Method of conducting business including making and selling a custom article of footwear

[0001] The present Patent Application refers to and claims the benefit of priority under 35 U.S.C. § 119(e) of each of the following U.S. Provisional Applications: Provisional Patent Application Ser. No. 60/360,784, filed on Mar. 1, 2002; Provisional Patent Application Ser. No. 60/345,951, filed on Dec. 29, 2001; and, Provisional Patent Application Ser. No. 60/292,644, filed on May 21, 2001. This Patent Application is a Continuation-In-Part of Patent Application Ser. No. 09/523,341, filed Mar. 10, 2000, entitled “Article of Footwear Having a Spring Element and Selectively Removable Components”, now U.S. Pat. No. 6,449,878. Further, the present Application refers to and claims the benefit of priority under 35 U.S.C. § 120 of each of the following Patent Applications: U.S. patent application Ser. No. 09/573,121, filed on May 17, 2000, entitled “Customized Article of Footwear and Method of Conducting Retail and Internet Business”, now U.S. Pat. No. 6,601,042, International Patent Application PCT/US01/07484, filed on Mar. 8, 2001, entitled “Article of Footwear Having a Spring Element and Selectively Removable Components”, and, International Patent Application PCT/US01/16159 filed on May 16, 2001, entitled “Customized Article of Footwear and Method of Conducting Retail and Internet Business”.

[0002] The present invention teaches an article of footwear including means for adjusting the length, width, girth, and foot shape. Further, the present invention teaches a customized article of footwear including a spring element, and selectively removable and replaceable components. Moreover, the present invention teaches a novel method of manufacturing articles of footwear, and also, a novel way of doing both retail and Internet business.

[0003] The article of footwear taught in the present invention includes a spring element which can provide improved cushioning, stability, and running economy. Unlike the conventional foam materials presently being used by the footwear industry, a preferred spring element is not substantially subject to compression set degradation and can provide a relatively long service life. The components of the article of footwear including the upper, insole, spring element, and sole can be selected from a range of options, and can be easily removed and replaced, as desired. Further, the relative configuration and functional relationship as between the forefoot, midfoot and rearfoot areas of the article of footwear can be readily modified and adjusted. Accordingly, the article of footwear can be customized by an individual wearer or specially configured for a select target population in order to optimize desired performance criteria. Moreover, the present invention teaches a novel method of manufacturing an article of footwear, and also, a novel way of doing both retail and Internet business.

[0004] Conventional athletic footwear typically include an outsole made of a thermoset rubber compound which is affixed by adhesive to a midsole made of ethylene vinyl acetate or polyurethane foam material which is in turn affixed by adhesive to an upper which is constructed with the use of stitching and adhesives. Because of the difficulty, time, and expense associated with renewing any portion of conventional articles of footwear, the vast majority are generally discarded at the end of their service life. This service life can be characterized as having a short duration when a wearer frequently engages in athletic activity such as distance running or tennis. In tennis, portions of the outsole can be substantially abraded within a few hours, and in distance running the foam midsole can become compacted and degrade by taking a compression set within one hundred miles of use. The resulting deformation of the foam midsole can degrade cushioning and footwear stability, thus contribute to the origin of athletic injuries. Accordingly, many competitive distance runners who routinely cover one hundred miles in a week's time will discard their athletic footwear after logging three hundred miles in order to avoid possible injury.

[0005] Even though the service life of conventional athletic footwear is relatively short, the price of athletic footwear has steadily increased over the last three decades, and some models now bear retail prices over one hundred and twenty dollars. However, some of this increase in retail prices has been design and fashion driven as opposed to reflecting actual value added. In any case, conventional athletic footwear remain disposable commodities and few are being recycled. The method of manufacture and disposal of conventional athletic footwear is therefore relatively inefficient and not environmentally friendly. In contrast with conventional athletic footwear, the present invention teaches an article of footwear that includes spring elements which do not take a compression set or similarly degrade, thus the physical and mechanical properties afforded by a preferred article of footwear remain substantially the same over a useful service life which can be several times longer than that of conventional articles of footwear. The present invention teaches an article of footwear which represents an investment, as opposed to a disposable commodity. Like an automobile, the preferred article of footwear includes components which can be easily renewed and replaced, but also components which can be varied and customized, as desired.

[0006] Published examples of devices and means for selectively and removably affixing various components of an article of footwear include, e.g., U.S. Pat. Nos. 2,183,277, 2,200,080, 2,220,534, 2,552,943, 2,588,061, 2,640,283, 2,873,540, 3,012,340, 3,818,617, 3,878,626, 3,906,646, 3,982,336, 4,103,440, 4,107,857, 4,132,016, 4,262,434, 4,267,650, 4,279,083, 4,300,294, 4,317,294, 4,351,120, 4,377,042, 4,535,554, 4,606,139, 4,807,372, 4,887,369, 5,042,175, 5,083,385, 5,317,822, 5,339,544, 5,410,821, 5,533,280, 5,542,198, 5,615,497, 5,628,129, 5,644,857, 5,657,558, 5,661,915, 5,678,327, 5,692,319, 5,729,916, 5,826,352, 5,896,608, 6,151,805, 6,247,249 B1, 6,282,814 B1, 6,324,772 B1, 6,332,281 B1, and application WO 02/13641 A1, all of these patents and patent applications hereby being incorporated by reference herein.

[0007] Conventional athletic footwear cannot be substantially customized for use by the consumer or wearer. The physical and mechanical properties of conventional athletic footwear are relatively fixed generic qualities. However, the body weight or mass and characteristic running technique of different individuals having the same footwear size can vary greatly. Often, the stiffness in compression of the foam material used in the midsole of athletic shoes can be too soft for individuals who employ more forceful movements, or who have greater body mass than an average wearer. Accordingly, conventional articles of athletic footwear do not provide optimal performance characteristics for individual wearers.

[0008] In contrast, the present invention permits a wearer to customize a preferred article of footwear. For example, the length, width, girth, and configuration of the upper, as provided by various last options, or by two or three dimensional modeling and footwear design equipment including computer software and data storage systems, or by two or three dimensional measurement devices such as scanners, as well as the type of footwear construction and design of the upper can be selected by the consumer or wearer. Further, the physical and mechanical properties of the article of footwear can be selected and changed as desired in order to optimize desired performance characteristics given various performance criteria or environmental conditions. For example, the configuration and geometry of the article of footwear, and the stiffness of the spring elements can be customized, as desired. In addition, the ability to easily remove, renew, and recycle the outsole portions of the preferred article of footwear can render the use of softer materials having enhanced shock and vibration dampening characteristics, but perhaps diminished wear properties, viable from a practical standpoint. Moreover, the outsole portion of the preferred article of footwear can be selected from a variety of options with regards to configuration, materials, and function.

[0009] The physical and mechanical properties associated with an article of footwear of the present invention can provide enhanced cushioning, stability, and running economy relative to conventional articles of footwear. The spring to dampening ratio of conventional articles of footwear is commonly in the range between 40-60 percent, whereas the preferred article of footwear can provide a higher spring to dampening ratio, thus greater mechanical efficiency and running economy. The preferred article of footwear can include an anterior spring element that underlies the forefoot area which can store energy during the latter portion of the stance phase and early portion of the propulsive phase of the running cycle, and then release this energy during the latter portion of the propulsive phase, thus facilitating improved running economy. It is believed the resulting improvement in running performance can approximate one second over four hundred meters, or two to three percent.

[0010] The preferred article of footwear can provide differential stiffness in the rearfoot area so as to reduce both the rate and magnitude of pronation, or alternately, the rate and magnitude of supination experienced by an individual wearer, thus avoid conditions which can be associated with injury. Likewise, the preferred article of footwear can provide differential stiffness in the midfoot and forefoot areas so as to reduce both the rate and magnitude of inward and/or outward rotation of the foot, thus avoid conditions which can be associated with injury. The preferred spring elements can also provide a stable platform which can prevent or reduce the amount of deformation caused by point loads, thus avoid conditions which can be associated with injury.

[0011] Again, the viability of using relatively soft outsole materials having improved shock and vibration dampening characteristics can enhance cushioning effects. Further, in conventional articles of footwear, the shock and vibration generated during rearfoot impact is commonly transmitted most rapidly to a wearer through that portion of the outsole and midsole which has greatest stiffness, and normally, this is a portion of the sole proximate the heel of the wearer which undergoes the greatest deflection and deformation. However, in the present invention a void space exists beneath the heel of a wearer and the ground engaging portion of the outsole. Some of the shock and vibration generated during the rearfoot impact of an outsole with the ground support surface must then travel a greater distance through the outsole and inferior spring element in order to be transmitted to the superior spring element and a wearer. In addition, in the present invention, a posterior spacer which can serve as a shock and vibration isolator, and also vibration decay time modifiers can be used to decrease the magnitude of the shock and vibration transmitted to the wearer of a preferred article of footwear.

[0012] There are many published examples of attempts to introduce functional spring elements into articles of footwear, e.g., U.S. Pat. Nos. 357,062, 1,088,328, 1,107,894, 1,113,266, 1,352,865, 1,370,212, 2,444,865, 2,447,603, 2,456,102, 2,508,318, 3,333,353, 4,429,474, 4,492,046, 4,314,413, 4,486,964, 4,506,460, 4,566,206, 4,771,554, 4,854,057, 4,878,300, 4,942,677, 5,042,175, 5,052,130, 5,060,401, 5,138,776, 5,159,767, 5,203,095, 5,279,051, 5,337,492, 5,343,639, 5,353,523, 5,367,790, 5,381,608, 5,437,110, 5,461,800, 5,528,842, 5,596,819, 5,636,456, 5,647,145, 5,678,327, 5,701,686, 5,729,916, 5,822,886, 5,875,567, 5,937,544, 5,940,994, 6,029,374, 6,195,915, 6,247,249 B1, 6,282,814 B1, 6,327,795, 6,330,757, 6,324,772 B1, French Patent 472,735, Italian Patent 633,409, European Patent Applications EP 0 890 321 A2, EP 1 048 233 A2, EP 1 033 087 A1, EP 1 025 770 A2, and PCT Patent Application WO 98/07341, all of these patents and patent applications hereby being incorporated by reference herein. Relatively few of these attempts have resulted in functional articles of footwear which have met with commercial success. The limitations of some of the prior art has concerned the difficulty of meeting the potentially competing criteria associated with cushioning and footwear stability. In other cases, the manufacturing costs of making prior art articles of footwear including spring elements have proved prohibitive.

[0013] The spring element and various other novel structures taught in the present invention can be used in a wide assortment of articles of footwear including but not limited to those used for running, walking, basketball, tennis, volleyball, cross-training, baseball, football, golf, soccer, cycling, sandals, hiking boots, and army boots. The present invention teaches an article of footwear which can provide a wearer with improved cushioning and stability, running economy, and an extended service life while reducing the risks of injury normally associated with footwear degradation. The preferred article of footwear provides a wearer with the ability to customize the fit, but also the physical and mechanical properties and performance of the article of footwear. Moreover, the preferred article of footwear is economical and environmentally friendly to both manufacture and recycle.

[0014] The present invention also teaches articles of footwear including means for adjusting the foot shape, length, width, and girth. For example, spring elements, anterior outsole elements, stability elements, and uppers having different configurations, and also alternate positions for selectively affixing various portions of an upper can be used to adjust and customize the fit of an article of footwear for an individual wearer. The upper can also include elastic or elongation means for adjusting the width, girth, and foot shape. The components of the article of footwear possibly including but not limited to the upper, insole, spring element, and sole can be selected from a range of options, and can be easily removed and replaced, as desired. Further, the relative configuration and functional relationship as between the forefoot, midfoot and rearfoot areas of the article of footwear can be readily modified and adjusted. Accordingly, the article of footwear can be configured and customized for a wearer or a select target population in order to optimize performance criteria, as desired.

[0015] Moreover, the present invention teaches a novel method of manufacturing articles of footwear, and also, a novel way of doing both retail and Internet business. For example, the anatomical features, configuration, and dimensions of a given wearer's foot and any other special needs, requirements, or preferences can be recorded by direct communication, observation, and measurement in a retail or medical setting, or alternately, by a wearer or other individual within their home or other remote site, and this data can be used to generate information and intelligence relating to the manufacture of a custom article of footwear. Conventional measuring or reproduction means such as rulers, measuring tapes, Brannock devices, two or three dimensional scanners, pressure sensors, infrared thermography, stereolithography, photographs, photocopies, FAX e-mail, cameras, images, tracings, video, television, computers and computer screens, software, data storage and retrieval systems, templates, molds, models, and patterns can be used to help determine and make selections relating to an individual's foot shape, length, width, girth, and the like.

[0016] Teachings which have been published or that otherwise constitute public information regarding the conduct of Internet or retail business include: U.S. Pat. No. 5,897,622 granted to Blinn et al.; U.S. Pat. No. 5,930,769 granted to Rose; U.S. Pat. No. 5,983,200 granted to Slotznick; U.S. Pat. No. 5,983,201 granted to Fay; U.S. Pat. No. 6,206,750 B1 granted to Barad et al.; the press release by Nike, Inc. dated Nov. 22, 1999 and the Internet website www.nike.com, and in particular, the section associated with the Nike iD program; the Internet website www.customatix.com; the Internet website www.adidas.com, and in particular, click on “products,” then click on “mass customization,” and see everything related to the “MI Adidas” initiative; and, the publication in the Oakland Tribune on Dec. 18, 1996 relating to the Internet Mall website, and in particular, the Internet website www.copycaps.com. All the patents recited in this paragraph are hereby incorporated by reference herein.

[0017] Given the provision of an adequate and ready stock of the various components anticipated for use in making the preferred articles of footwear, and the information and intelligence created from the data relating to an individual wearer or target population, a worker and/or automated system can assemble or manufacture a customized article of footwear within five minutes. In fact, it is possible to assemble a selected and customized article of footwear according to the present invention in less than one minute using a single fastener. This can be accomplished at the point of purchase or service center which can be located in a retail or medical facility, or alternatively, at a remote manufacturing environment. Accordingly, similar to the rapid delivery eyewear service centers and retail stores which presently exist, a consumer can now also be provided with a custom article of footwear within minutes. Alternately, if and when an individual's data is received from a remote site at the Website or other address of a company which practices the present invention, and then transmitted to a manufacturing or assembly center, a custom article of footwear can be made and possibly delivered to an individual's home or other designated address by same day or overnight service, as desired.

[0018] A preferred article of footwear can include an anterior side, a posterior side, a medial side, a lateral side, a longitudinal axis, a transverse axis, an upper, a sole, at least one fastener, and a spring element comprising a superior spring element and an inferior spring element. The superior spring element can extend substantially between the posterior side and the anterior side of the article of footwear and be substantially positioned within the upper in order to secure the upper to the superior spring element. The inferior spring element and the sole can be substantially positioned inferiorly and externally with respect to the upper, and the superior spring element can be affixed in functional relation to the inferior spring element by at least one fastener. The article of footwear can further include an upper having a plurality of openings on the inferior side in the forefoot area. Further, an anterior outsole element including a backing can be at least partially positioned within the upper. However, the substantial portion of the anterior outsole element including the ground engaging portion and a plurality of traction members can project through the openings in the upper, thus the substantial portion of the anterior outsole element can nevertheless be substantially positioned inferiorly and externally relative to the upper. In an alternate embodiment, the article of footwear can further include an upper having a plurality of openings on the inferior side, but also on a portion of the medial side, lateral side, and anterior side in the forefoot area, and the anterior outsole element can then include a backing having an elevated profile and traction members that extend upwards about a portion of the medial side, lateral side, and anterior side of the upper. The article of footwear can further include an insole, a stability element, a sole including an anterior outsole element, a middle outsole element, and a posterior outsole element having a backing, and also closure means such a strap including VELCRO® hook and pile, or a strap including openings and eyelets for receiving conventional shoe laces. A strap can encompass the medial side, lateral side, inferior side, and superior side of the upper, and an alternate embodiment of a strap can also include a portion that encompasses the posterior side of the upper. In any case, a strap can be selectively removable and replaceable. In an alternate embodiment, the upper can be over-lasted, that is, over-sized in order to accommodate a removable and replaceable midsole cushioning element which can be inserted into the forefoot area between the insole and the upper. The insole can include an elevated profile about the medial side, lateral side, anterior side, and posterior side for protecting a wearer's foot from contact with an elevated portion of an anterior outsole element, a stability element, a side support, or a heel counter. The inferior side of the upper can include an opening in the rearfoot area for positioning a removable and replaceable cushioning element such as a fluid-filled bladder or a resilient foam material. The superior side of an insole can include an opening in the rearfoot area for positioning a removable and replaceable cushioning element such as a fluid-filled bladder or a resilient foam material. A fluid-filled bladder can be positioned between the superior spring element or posterior spring element and the inferior spring element.

[0019] The inferior spring element can be affixed in functional relation to the superior spring element and can project rearward and downward therefrom forming a V-shape. The superior spring element can further include an anterior spring element and a posterior spring element affixed together in functional relation, and the inferior spring element can be affixed in functional relation to the posterior spring element. The anterior spring element and posterior spring element can be affixed together in an overlapping relationship. The anterior spring element can further include a projection, and the posterior spring element can include a recess for accommodating the anterior spring element. The superior spring element can have a configuration generally corresponding to the bottom net of the last of an article of footwear and can either be generally planar, or curved. At least a portion of the superior spring element can be curved to mate with the anatomy of a wearer. Further, the superior spring element can possibly also include a side stabilizer or a heel counter. An anterior spring element can have a curved shape and incorporate toe spring. The amount of toe spring incorporated in an anterior spring element can be in the range between 0-40 mm, and in particular, in the range between 10-30 mm A substantial portion of the anterior spring element can extend anterior of 50 percent of the length of the upper as measured from the posterior side of the upper, whereas a substantial portion of the inferior spring element can extend within 50 percent of the length of the upper as measured from the posterior side of the upper. A posterior spring element can include a side stabilizer. Further, a superior spring element or posterior spring element can include an integral heel counter.

[0020] The inferior spring element can include a longitudinal axis, a transverse axis, and a flexural axis. The flexural axis can be consistent with the transverse axis. An inferior spring element including a flexural axis consistent with the transverse axis can have a symmetrical configuration on both the medial side and lateral side. Alternately, an inferior spring element including a flexural axis consistent with the transverse axis can have an asymmetrical configuration, and can have greater concavity downwards adjacent the transverse axis on the medial side than on the lateral side. Alternately, the inferior spring element can include a flexural axis deviated from the transverse axis in the range between 10-50 degrees. In particular, given an average individual wearer who would be biomechanically characterized as a rearfoot striker, it can be advantageous for the flexural axis to be deviated from the transverse axis in the range between 10-30 degrees in footwear intended for walking or running. Accordingly, the length of the effective lever arm on the medial side of the inferior spring element will be shorter than that on the lateral side, that is, as measured between the posterior side of the inferior spring element and the location of the flexural axis on each respective side. One way of expressing the length differential of the effective lever arms of the inferior spring element on the medial side versus the lateral side is with a ratio. In this regard, it can be advantageous for effecting rearfoot stability that the ratio of the length of the effective lever arms on the lateral side relative to those on the medial side be in the range between 1/1 to 2/1, and in particular, in the range between 1.25/1 to 2/1, and preferably in the range between 1.25/1 to 1.75/1. Further, in a men's size 9 article of footwear, the posteriormost position of the flexural axis on the medial side can be in the range between 1-6 inches from the posterior side of the upper, and in particular, in the range between 2-4 inches from the posterior side of the upper. An inferior spring element including a flexural axis deviated from the transverse axis can have a symmetrical configuration on both the medial side and lateral side. Alternately, an inferior spring element including a flexural axis deviated from the transverse axis can have an asymmetrical configuration, and can have greater concavity downwards adjacent the transverse axis on the medial side than on the lateral side. Whether the flexural axis be consistent with the transverse axis or be deviated therefrom, an inferior spring element having a symmetrical configuration on the medial side and lateral side can include an anterior portion extending between its anterior side and an anterior tangent point, a middle portion including an anterior curve extending between the anterior tangent point and a posterior tangent point, and a posterior portion extending between the posterior tangent point and the posterior side of said inferior spring element. It can be advantageous that the anterior curve be configured to have a symmetrical fitted radius of curvature. Moreover, the posterior portion of the inferior spring element can be inclined, or include a posterior curve.

[0021] The inferior spring element can attain maximum separation from the superior spring element at a position anterior of the posterior side of the inferior spring element, and can substantially maintain the maximum separation between that position and the posterior side of the inferior spring element. Alternately, the inferior spring element can attain maximum separation from the superior spring element at a position anterior of the posterior side of the inferior spring element, and the separation can then be decreased between that position and the posterior side of the inferior spring element. The inferior spring element can be concave downwards near the anterior side of the inferior spring element, but can be concave upwards or convex near the posterior side of the inferior spring element. The inferior spring element can be made in a laminate configuration or structure. Further, the inferior spring element can be made in a tapered configuration or structure. An inferior spring element can exhibit less stiffness in compression on the lateral side relative to the medial side, and it can be advantageous for walking and running activity that the differential stiffness be in the range between two-to-three to one.

[0022] The spring element can be made of a fiber composite material, and an unidirection carbon fiber composite material including a toughened epoxy can be preferred for use. Alternately, the spring element can be made of a metal material such as spring steel or titanium. The spring element is preferably made of a material having spring characteristics such that the material is capable of storing and returning at least 70 percent of the energy imparted thereto. A preferred fiber composite material, or alternately, a metal material such as spring steel or spring grade titanium is capable of storing and returning at least 90 percent of the energy imparted thereto when their mechanical characteristics are measured using ASTM 790. The spring element can provide deflection in the range between 5-50 mm. For example, deflection approximately in the range between 8-15 mm could be selected by some wearers for a training shoe intended for use in running at a relatively fast pace, a racing flat, or a track spike. Alternately, deflection approximately in the rage between 15-50 mm could be selected by some wearers for a training shoe intended for use in running at a relatively slow pace. The superior spring element can have a thickness in the range between 0.5-10.0 mm. The superior spring element can include an anterior spring element having a thickness in the range between 0.5-2.5 mm, and in particular, in the range between 1.0-1.75 mm. The superior spring element can also include a posterior spring element having a thickness in the range between 1-10 mm. When the superior spring element, or posterior spring element has a three dimensional shape in the rearfoot area including an integral heel counter or side counters, the superior spring element or posterior spring element can have a thickness in the range between 1-5 mm The inferior spring element can have a thickness in the range between 3-10 mm. The spring element can include areas having different thickness, notches, slits, or openings which can serve to produce differential stiffness characteristics when the spring element is loaded. The anterior spring element can include at least one longitudinal notch or slit, and also a plurality of transverse notches or slits on the medial side and lateral side for influencing the flexural modulus and torsional characteristics in a desired manner. It can sometimes be advantageous for the transverse notches or slits on the lateral side to extend for a greater distance relative to those present on the medial side, and also for a pair of opposing notches or slits on the medial side and lateral side to approximately correspond the position of the metatarsal-phalangeal joints, that is, be positioned between 60-70 percent of the length of the upper as measured from the posterior side. The spring element can include different types, orientations, configurations, and numbers of fiber composite layers in different areas in order to achieve differential stiffness when the spring element is loaded. Accordingly, the flexural modulus or stiffness exhibited by a spring element in the rearfoot area, midfoot area, forefoot area, and also that exhibited about any axis can be engineered, as desired.

[0023] The article of footwear can further include a posterior spacer between the superior spring element or posterior spring element and the inferior spring element. Further, an anterior spacer can be used between a superior spring element and an anterior spring element, or alternately between an anterior spring element and an inferior anterior spring element. An anterior spacer or posterior spacer can also possibly be positioned between the anterior spring element and the posterior spring element. An anterior spacer and a posterior spacer can have a wedge or sloped shape. An anterior spacer can have a gently rounded shape near the posterior side. The shape of a posterior spacer and an anterior spacer can be used to modify the configuration and performance of a spring element and that of an associated article of footwear.

[0024] In an alternate embodiment of an article of footwear, the superior spring element can extend substantially between the posterior side and anterior side of the upper. Again the superior spring element can consist of a posterior spring element and an anterior spring element configured in an overlapping relationship. The inferior spring element can be affixed in functional relation to the superior spring element or posterior spring element, thus form a spring element having a v-shape in the rearfoot area. Further, an inferior anterior spring element can be positioned and affixed in function relation to an anterior spacer and the superior spring element or anterior spring element, thus forming a spring element having a v-shape in the forefoot area as well. The inferior anterior spring element can include at least one longitudinal notch or slit, and also at least one transverse notch or slit for influencing the flexural and torsional characteristics in a desired manner. Again, as with all the other major components of the article of footwear, the inferior anterior spring element, anterior spacer, and anterior outsole element can be selectively removed and replaced, as desired.

[0025] Cushioning elements such as fluid-filed bladders or foam materials can be formed or affixed to the backing portion of the anterior outsole element, and also to the backing portion of the posterior outsole element. Alternately, a cushioning element can include a web portion, backing portion, or flange, and the cushioning element can be inserted into a pocket in the anterior outsole element or the posterior outsole element and a substantial portion of the cushioning element can then project through an opening in the backing portion of the respective outsole element. Accordingly, the cushioning element can be affixed in position, but the cushioning element can nevertheless be selectively removable and replaceable. Again, a fluid-filled bladder can be positioned between the superior spring element or posterior spring element and the inferior spring element. Further, a fluid-filled bladder can also be positioned on the inferior side of the inferior spring element. In addition, a fluid-filled bladder positioned between the superior spring element or posterior spring element and the inferior spring element including at least one chamber can be in fluid communication with another chamber or fluid filled bladder positioned on the inferior side of the inferior spring element. Fluid-filled bladders including valves that can also serve as a motion control device can be used. Moreover, fluid-filled bladders that form part of a larger dynamically-controlled cushioning system can be used. Such an article of footwear can include at least one fluid-filled bladder including a plurality of chambers, a control system possibly including a CPU, a pressure detector, and a regulator for modulating the level of fluid communication between different fluid-filled bladders or chambers.

[0026] The sole can consist of a single component, or alternately can consist of a two part component including an anterior outsole element and a posterior outsole element, or alternately can consist of a three part component including an anterior outsole element, a middle outsole element, and a posterior outsole element. The anterior outsole element can be affixed in functional relation to the superior spring element, or anterior spring element. The anterior outsole element can include an undercut portion for mating with openings in the upper, thus providing a snap fit with the upper. The posterior outsole element and the middle outsole element can be affixed to the inferior spring element, and thereby be affixed in functional relation to the superior spring element. The sole can include a midsole and an outsole, or merely an outsole. The sole can also include an outsole having a backing, a tread or ground engaging surface, traction members, a rocker configuration, and lines of flexion, whether in partial or complete combination. The sole can include a bicycle cleat, or traction members suitable for use on natural or artificial turf The anterior outsole element can have a generally planar configuration, or alternately, a three dimensional wrap configuration. The anterior outsole element can be made in different length sizes, width sizes, and last or foot shapes, as desired. The backing portion of the anterior outsole element can include an elevated profile and thereby substantially define the shape of the upper in the forefoot area. Further, the backing portion of the anterior outsole element can be molded and cut to a desired length, width, girth and footshape, as desired. The backing portion of an anterior spring element can be substantially positioned in the forefoot area, or alternately, can substantially extend full length A gasket can be used to seal the junction between the anterior outsole element and the upper. The sole can further include a cushioning element such as a fluid-filled bladder, or a foam material. A cushioning element can be affixed in functional relation to the backing portion of an outsole element. Alternately, a cushioning element can include a web portion, backing portion, or flange, and the cushioning element can be inserted into a pocket in the outsole element and a substantial portion of the cushioning element can project through a opening in the backing portion of the outsole element. Accordingly, the cushioning element can be affixed in position, but the cushioning element can nevertheless be selectively removable and replaceable. A middle outsole element can be made of at least one fluid-filled bladder, or alternately be made of a resilient foam material. In a bottom plan view, a middle outsole element can have a generally triangular shape. A cushioning element can be positioned on the medial side in order to create a differential cushioning and stability effect. In an alternate embodiment, the sole can be affixed in functional relation to the exterior of the upper. The anterior outsole element can include male mating structures for mating with female mating structures on the superior spring element. Again, the sole can be selectively removable and replaceable, and can be made with a multiplicity of alternate configurations and materials which are particularly suitable for use given specific environmental conditions and performance tasks.

[0027] The upper can further include a sleeve for affixing at least a portion of the superior spring element in function relation thereto. The upper can be substantially made using a single piece of textile material that can be cut by an automatic cutting machine, and stitched using an automatic three dimensional sewing machine. Alternately, the upper can be substantially made of a molded plastic material. Alternately, the upper can be substantially made of a three-dimensional woven textile material.

[0028] The components of the article of footwear including the upper, insole, superior spring element possibly including an anterior spring element and a posterior spring element, inferior spring element, sole including an anterior outsole element and a posterior outsole element having a backing, and at least one fastener can be selectively removable and replaceable. A fastener can include a male part and a female part, and can further include a geometric shape such as a square, triangular, pentagon, hexagon, or other shape which can substantially prevent the rotation of various components of a spring element relative to one another. A fastener can include locking means such as a plastic material whereby the male part and female part cannot be accidentally loosened.

[0029] The article of footwear can further include a spring guard for protecting the posterior aspect of the mating portions of the superior spring element or posterior spring element and the inferior spring element. The article of footwear can further include a vibration decay time modifier. The vibration decay time modifiers can include a head and a stem The head of the vibration decay time modifiers can be dimensioned and configured for vibration substantially free of contact with the base of the posterior spacer or spring element in directions which substantially encompass a 360 degree arc and normal to the longitudinal axis of the stem.

[0030] In an alternate embodiment of an article of footwear, the spring element can consist of a superior spring element which can include an anterior spring element and a posterior spring element affixed together in functional relation, but not include an inferior spring element projecting rearward and downward therefrom. In an alternate embodiment, the anterior spring element can include a medial anterior spring element and a lateral anterior spring element that are removably affixed in functional relation to the posterior spring element. In an alternate embodiment, the anterior spring element and inferior spring element can consist of a single component, or alternately, can be affixed together in functional relation, and the posterior spring element can be affixed in functional relation thereto. An alternate article of footwear can have an anterior side, a posterior side, a medial side, a lateral side, a superior side, an inferior side, a longitudinal axis, a transverse axis, and a plurality of fasteners. The upper can include a plurality of alternate openings on the inferior side at a plurality of different positions, and the alternate openings can be offset by a distance corresponding to a change in one standard width size and configured for receiving the plurality of fasteners. Spring elements can be made in different configurations for accommodating different length sizes, width sizes, and also different last or foot shapes. A spring element can have a plurality of openings, or alternately, can have notches or slits for accommodating a plurality of fasteners, and the spring element can be positioned within the upper. The upper can then be removably affixed in functional relation to the spring element by the plurality of fasteners, as desired.

[0031] An article of footwear can have an anterior side, a posterior side, a medial side, a lateral side, a superior side, an inferior side, a longitudinal axis, and a transverse axis. The article of footwear can include an upper including a plurality of openings on the inferior side, an insole, a fastener, and a sole including an anterior outsole element and a posterior outsole element. The anterior outsole element can be positioned in functional relation within the upper and can include a plurality of traction members. The traction members can substantially project through the openings on the inferior side of the upper. The article of footwear can include a spring element including a superior spring element and an inferior spring element, and the superior spring element can extend substantially between the posterior side and the anterior side of the article of footwear and be substantially positioned in functional relation within the upper to secure the upper to the superior spring element. The inferior spring element can be substantially positioned inferiorly and externally with respect to the upper. The posterior outsole element can be affixed in function relation to the inferior spring element and the superior spring element by a fastener. The upper, insole, superior spring element, inferior spring element, anterior outsole element, posterior outsole element, and fastener can be selectively removable and replaceable. The article of footwear can further include a stability element, a sole including an anterior outsole element, a middle outsole element, and a posterior outsole element having a backing, a midsole cushioning element such as a fluid-filled bladder or a resilient foam material, and closure means such a strap including VELCRO® hook and pile, or a strap including openings and eyelets for receiving conventional shoe laces.

[0032] The present invention teaches a method of making a custom article of footwear comprising the steps of:

[0033] a) Collecting data relating to an individual's preferences and the anatomical features and measurements of said individual's foot;

[0034] b) Creating information and intelligence for making said article of footwear for said individual;

[0035] c) Providing said information and intelligence to a physical location at which said article of footwear can be made;

[0036] d) Selecting a foot length size;

[0037] e) Selecting a three dimensional foot shape including width and girth dimensions;

[0038] f) Selecting a plurality of footwear components including an upper including closure means, an insole, a spring element, at least one mechanical fastener, and a sole which can be selectively removed and replaced using mechanical engagement means including said at least one mechanical fastener; and,

[0039] g) Removably securing said plurality of footwear components including said upper including closure means, said insole, said spring element, said at least one mechanical fastener, and said sole in functional relation with said mechanical engagement means including said at least one mechanical fastener, and completing the assembly and making of said article of footwear.

[0040] The present invention also teaches a method of conducting business including making and selling a custom article of footwear comprising the steps of:

[0041] a) Collecting data relating to an individual's preferences and the anatomical features and measurements of said individual's foot;

[0042] b) Creating information and intelligence for making said article of footwear for said individual;

[0043] c) Providing said information and intelligence to a physical location at which said article of footwear can be made;

[0044] d) Providing a plurality of footwear components, and a plurality of variations of each footwear component, said footwear components comprising footwear uppers, footwear spring elements, at least one mechanical fastener, and footwear soles which are capable of being assembled to form said custom article of footwear using said at least one mechanical fastener, and each of the components being selectively interchangeable and being removable and replaceable;

[0045] e) Selecting a plurality of footwear components from the provided sources including at least an upper, a spring element, at least one mechanical fastener, and a sole which can be selectively removed and replaced;

[0046] f) Removably securing said plurality of footwear components including said upper, said spring element, and said sole in functional relation with said at least one selected mechanical fastener, thereby making said custom article of footwear; and,

[0047] g) Causing said custom article of footwear to be delivered to a designated address.

[0048] The physical location can be a retail store and the assembly of the article of footwear can be completed within thirty minutes. Preferably, the assembly of the article of footwear can be completed within five minutes, and even in less than one minute. Alternately, the physical location can be a medical facility. Alternately, the physical location can be a manufacturing center for making the article of footwear, or a distribution center, and the data relating to the individual's preferences and the anatomical features and measurements of the individual's foot can be transmitted from a remote site, and the article of footwear can be caused to be delivered from the manufacturing center or the distribution center to a designated address. The data can be transmitted electronically by means including but not limited to the Internet, telephone and Fax. In the continental United States, and possibly within many other host countries in which the novel method of making an article of footwear and conducting business would be practiced, an article of footwear can be caused to be delivered to a designated,address within a selected number of working days. For example, the article of footwear can sometimes be delivered the same day, or the next day, or otherwise within a different selected number of working days, as desired.

[0049] The ability to easily customize and adapt the preferred article of footwear in a desired manner can render the present invention suitable for use in running, walking, basketball, tennis, volleyball, cross-training, baseball, football, golf, soccer, cycling, sandals, skating, hiking boots, and army boots.

[0573] The article of footwear taught in the present invention includes a spring element which can provide improved cushioning, stability, and running economy. Unlike the conventional foam materials presently being used by the footwear industry, a preferred spring element is not substantially subject to compression set degradation and can provide a relatively long service life. The components of the article of footwear including the upper, insole, spring element, and sole can be selected from a range of options, and can be easily removed and replaced, as desired. The present invention also teaches an article of footwear including means for adjusting the length, width, girth and foot shape. Further, the relative configuration and functional relationship as between the forefoot, midfoot and rearfoot areas of the article of footwear can be readily modified and adjusted. Accordingly, the article of footwear can be customized by a wearer or specially configured for a select target population in order to optimize desired performance criteria. Moreover, the present invention teaches a novel method of manufacturing an article of footwear, and also, a novel way of doing both retail and Internet business.

[0574] FIG. 1 is a medial side view of an article of footwear 22 including a spring element 51 consisting of at least two portions, a superior spring element 47 and an inferior spring element 50. The portions of spring element 51 can be integrally formed in a single component, but can alternately be formed in at least two parts which can be affixed together by adhesives. Preferably, the superior spring element 47 is capable of being removably affixed in functional relation to the inferior spring element 50, upper 23, and sole 32 with the use mechanical engagement means including at least one mechanical fastener 29.

[0575] A mechanical fastener 29 can be made, e.g., of metal, ceramic, composite, thermoplastic, or thermoset materials. Threaded nuts and bolts, rivets, pop-rivets, push-rivets, snap rivets, snaps, hooks, clips, mating male and female structures, quarter turn fasteners, bayonet style fasteners, quick-release fasteners, and the like, can be used as a fastener. Preferred metals for use in a fastener can include aluminum, stainless steel titanium, zinc coated steel, and other metals or treatments that are resistant to substantial degradation caused normal oxidation and corrosion. Thermoplastic snap-rivets 151 and push rivets 152 made and distributed by Richco, Inc. of Chicago, Ill. are shown in FIGS. 481-482. A large variety of fasteners are made, e.g., by Penn Engineering & Manufacturing Corporation of Danboro, Pa., Avibank Manufacturing, Inc. of Burbank, Calif., Atlas Engineering of Kent, Ohio, Stayfast Products, Inc. of Fort Mill, S.C., DFS International Inc. of Orlando, Fla., and Fairchild, Inc. of Simi Valley, Calif. Shown in FIG. 483 is a standard full hex blind threaded insert 153 made by Atlas Engineering, Inc., and similar configurations are also available from Stayfast Products, Inc. Armand Savoie of MacNeill Engineering of Marlborough, Mass. is the inventor of so-called “Q-lock” fasteners taught in U.S. Pat. Nos. 6,151,805, and 6,332,281, and these patents are hereby being incorporated by reference herein Fasteners having a threaded portion which further include a portion that can be collapsed or crimped in order to grip a portion of a structure into which they are being fitted are known in the prior art. When a thermoplastic material is used, a fastener can possibly be formed or affixed in position with the use of heat and pressure, welding, adhesive, polymerization, and then later be removed by destructive method or again with the use of heat and pressure. For example, the distal end of a male portion of a fastener can be melted and formed into a rivet like shape with the use of heat and pressure. When a thermoset material is used, a fastener can possibly be formed or affixed in position with the use of heat and pressure, polymerization, vulcanization, and later be removed with the use of heat and pressure, or destructive method. Contact adhesives and light cure adhesives can also be used to create or affix a fastener.

[0576] Preferably, a selectively removable and replaceable mechanical fastener 29 can be used, thus enabling some or all of the components of a spring element 51 and an article of footwear 22 to be removed and replaced, as desired. A fastener can include Allen head or star drive mechanical mating configurations for use with a like installation and removal tool. If desired, a fastener can also be torque limited so as to tighten to an appropriate and desired maximum torque value. So-called “smart bolts” developed for NASA which are known by the tradename INTELLIGENT FASTENER® and made by Ultrafast, Inc. of Malvern, Pa. can be used. Fasteners known in the prior art having a male portion including threads that are coated with a thermoplastic or other locking material, or alternately, a fastener having a female portion including a thermoplastic or other locking material, can also be used in order to prevent loosening during use. Moreover, fasteners including mating male and female parts which can be easily and quickly coupled and released by so-called quarter turn, bayonet, or quick-release structures and methods can be advantageous for use. In this regard, the thickness of a superior spring element 47, inferior spring element 50, and upper 23 can be known, thus standardized or graded for various sizes of an article of footwear. Accordingly, it is possible to design and engineer fasteners 29 including mating male and female parts that can be easily and quickly coupled and released by so-called quarter turn, bayonet, or quick-release structures and methods. Moreover, alternate inferior spring elements 50 having different thickness within an engineered and preferred selected range can be accommodated and used, as desired.

[0577] Again, it can be readily understood that other conventional means can be used to affix the upper 23 in functional relation to the spring element 51 and outsole 43, such as VELCRO® hook and pile, or other mechanical engagement means and devices. For example, as shown in FIG. 4, a portion of the posterior outsole element 46 can slip over and trap a portion of the inferior spring element 50 and then be secured with fasteners 29. Further, at least one hook 27 can extend from the backing 30 of anterior outsole element 44 and engage a portion of the upper 23 or the superior spring element 47 as a portion of the outsole 43 is attached to a preferred article of footwear 22.

[0578] Again, published examples of devices and means for selectively and removably affixing various components of an article of footwear include, e.g., U.S. Pat. Nos. 2,183,277, 2,200,080, 2,220,534, 2,552,943, 2,588,061, 2,640,283, 2,873,540, 3,012,340, 3,818,617, 3,878,626, 3,906,646, 3,982,336, 4,103,440, 4,107,857, 4,132,016, 4,262,434, 4,267,650, 4,279,083, 4,300,294, 4,317,294, 4,351,120, 4,377,042, 4,535,554, 4,606,139, 4,807,372, 4,887,369, 5,042,175, 5,083,385, 5,317,822, 5,339,544, 5,410,821, 5,533,280, 5,542,198, 5,615,497, 5,628,129, 5,644,857, 5,657,558, 5,661,915, 5,678,327, 5,692,319, 5,729,916, 5,826,352, 5,896,608, 6,151,805, 6,247,249 B1, 6,282,814 B1, 6,324,772 B1, 6,332,281 B1, and application WO 02/13641 A1, all of these patents and patent applications hereby being incorporated by reference herein.

[0579] Also shown in FIG. 1 is an upper 23 including a heel counter 24, tip 25, vamp 52, anterior side 33, posterior side 34, medial side 35, top or superior side 37, bottom or inferior side 38, forefoot area 58, midfoot area 67, rearfoot area 68, midsole 26, a spring element 51 including an inferior spring element 50, an outsole 43 including an anterior outsole element 44 and posterior outsole element 46 having a tread or ground engaging surface 53, and the presence of toe spring 62. The upper 23 can be made of a plurality of conventional materials known in the footwear art such as leather, natural or synthetic textile materials, paper or cardboard, stitching, adhesive, thermoplastic material, foam material, and natural or synthetic rubber. Since the various components of a preferred article of footwear 22 can be easily removed and replaced, a wearer can select a custom upper 23 having a desired size, shape, design, construction and functional capability. The article of footwear 22 can also include means for customizing the shape, width, and fit of the upper 23 such as taught in U.S. Pat. Nos. 5,729,912, 5,813,146, WO 99/24498 A2, and the like, the recited patents and patent application hereby being incorporated by reference herein. Further, the present invention teaches novel devices and methods for customizing the width, girth, and last or foot shape of the preferred article of footwear, as discussed in greater detail below. Moreover, the article of footwear 22 can include a custom insole 31 using light cure material as taught in the applicant's U.S. Pat. No. 5,632,057, hereby incorporated by reference herein.

[0580] The upper 23 can be made with the use conventional patterns, materials, and means known in the prior art. Accordingly an upper 23 can include a natural or synthetic textile material 137 such as a woven or knit fabric, and the like. It can be readily understood that the textile material 137 can consist of a three dimensional textile material, a multi-layer textile material, water resistant or waterproof materials, shape memory textile materials, or stretchable and elastic textile materials, and the like. The textile material 137 included in the upper 23 can also be formed by three dimensional weaving or knitting methods known in the prior art such as in the manufacture of socks, and a suitable pattern for use can be derived or cut therefrom.

[0581] Alternately, the textile material 137 forming at least a portion of the upper 23 can be made in the origami-like patterns taught in U.S. Pat. No. 5,604,997 granted to Dieter, U.S. Pat. No. 5,729,918 granted to Smets, U.S. Pat. No. 6,295,679 B1 granted to Chenevert, patent applications WO 02/13641 A1 by Long and WO 02/23641 A1 by Kilgore et al, and the like, all of these patents and patent applications being assigned to Nike, Inc. Further, the upper 23 can be made in accordance with the teachings of U.S. Pat. No. 6,237,251 granted to Litchfield et al., and also those of U.S. Pat. No. 6,299,962 granted to Davis et al, and the like, both of these patents being assigned to Reebok International, Ltd. In addition, generally similar to the teachings of U.S. Pat. No. 6,024,712 granted to Iglesias et al., the upper 23 can include a textile material that is overmolded with a thermoplastic material. All of the patents and patent applications recited in this paragraph are hereby incorporated by reference herein.

[0582] As shown in FIG. 349, the textile material 137 can be impregnated or overmolded with a plastic material 138 forming a stability element 136d, e.g., a relatively rigid thermoplastic material such as nylon, polyester, or polyethylene, or alternatively, an elastomeric thermoplastic material such as those made by Advanced Elastomer Systems that are recited elsewhere herein, a foam thermoplastic material, a rubber material, or a polyurethane material The textile material 137 can be impregnated or overmolded while positioned in a substantially planar two dimensional orientation as shown in U.S. Pat. No. 6,299,962 granted to Davis et al, or alternately, while positioned in a relatively complex three dimensional shape on a footwear last 80, mold, or the like. For example, stability element 136d shown in FIG. 349 can be made of a thermoplastic material or a polyurethane material that is directly injection molded and bonded to the upper 23.

[0583] Alternately, a foam material can be applied to the upper 23 as taught in U.S. Pat. No. 5,785,909 granted to Chang et al., and also U.S. Pat. No. 5,885,500 granted to Tawney et al., and the like, both patents being assigned to Nike, Inc., these recited patents hereby being incorporated by reference herein. The textile material 137 can possibly be impregnated or overmolded with the use of a spray, dipping, or roller application generally similar to that known in the screenprinting prior art. If the plastic material 138 is of the thermoplastic variety, it can then be caused to cool and take a set.

[0584] Alternately, a thermoset material which is used to impregnate or overmold the textile material 137 can be caused to cross-link by conventional means known in the prior art. As taught in the applicant's pending U.S. Ser. No. 09/570,171, filed May 11, 2000, light-cure materials which can be caused to set and cure upon exposure to a specific range of light frequency and wavelength having adequate power can also be used. When the inferior side 38 of the upper 23 includes a plurality of openings 72 for accommodating the passage of a plurality of traction members 115 associated with the anterior outsole element 44 therethrough, it can be advantageous that the inferior side 38 of the upper 23 in the forefoot area 58, and possibly also that the midfoot area 67 and rearfoot area 68 be impregnated or overmolded by plastic material 138, or other suitable material. Alternately, the inferior side 38 of the upper 23 can be otherwise reinforced in order to enhance its structural integrity.

[0585] As shown in FIG. 350, the upper 23 can be made in general accordance with the so-called Huarache style commercialized by Nike, Inc. The textile material 137 can have elastic qualities, or alternatively, a rubber, neoprene foam rubber, polyurethane, or other material can be used in those areas of the vamp 52 and quarters 119 in which the location of a textile material 137 is indicated. In this regard, the textile material 137, or alternately, a substitute material having substantial elastic characteristics extends into the collar area 122 in order to facilitate entry and exit of a wearer's foot. Moreover, it can be readily understood that the upper 23 can include removable quarters including openings 72 and eyestays 139 for accommodating laces, straps 118, or other conventional closure means.

[0586] The upper 23 can also be made of new thermoplastic materials which have not yet been used to make articles of footwear that are biodegradable and environmentally friendly. For example, textile materials made from polylactic acid polymers derived from corn or other vegetation known by the tradename NATUREWORKS® fibers are presently under development and being commercialized by Cargill Dow Polymers LLC of Minneapolis, Minn. in cooperation with the Kanebo Corporation which is associated with the Itochu Corporation of Osaka, Japan. The physical and mechanical properties of fibers and thermoplastic materials derived from polylactic acid generally compare favorably with many existing fibers and thermoplastic materials, but unlike the vast majority of the synthetic fibers and thermoplastic materials presently being used in the manufacture of articles of footwear, those derived from polylactic acid are capable of substantially biodegrading when buried in the soil over a period of two to three years. Moreover, other biodegradable and environmentally-friendly plastic materials and fibers can also be suitable for use.

[0587] As shown in FIG. 4, the anterior outsole element 44 and posterior outsole element 46 can include a backing 30 portion. The outsole 43 can be firmly secured in function relation to the upper 23 and spring element 51 with the use of at least one fastener 29. In an alternate embodiment, it is possible to configure the posterior outsole portion 46 such that a portion can slip over and trap the posterior side of the inferior spring element 50, and the posterior outsole element 46 can then be secured with at least one fastener 29 near the anterior side of the posterior outsole element 46 and inferior spring element 50. Since the posterior outsole element 46 consists of a resilient elastomer such as natural or synthetic rubber, during footstrike and the early portion of the braking phase of the gait cycle, the posterior outsole element 46 can become somewhat elongated and distended along the longitudinal or anterior to posterior axis and to lesser degree the medial to lateral or transverse axis, and this can further contribute to reducing the shock and vibration generated upon impact, as the forces and direction of loading during footstrike and the braking phase have not only vertical or z axis, but also x and y axis components.

[0588] The ground engaging portion 53 of the outsole 43 can be made of a natural or synthetic rubber material such as nitrile or styrene butadiene rubber, a thermoplastic material, an elastomer such as polyurethane, a hybrid thermoplastic rubber, and the like. Further, these materials can possibly be suitable for use when blown or foamed. Suitable hybrid thermoplastic and rubber combinations include dynamically vulcanized alloys which can be injection molded such as those produced by Advanced Elastomer Systems, 338 Main Street, Akron, Ohio 44311, e.g., SANTOPRENE®, VYRAM®, GEOLAST®, TREFSIN®, VISTAFLEX®, GEOLAST®, DYTROL XL®, and taught in the following Patents, e.g., U.S. Pat. Nos. 5,783,631, 5,779,968, 5,777,033, 5,777,029, 5,750,625, 5,672,660, 5,609,962, 5,591,798, 5,589,544, 5,574,105, 5,523,350, 5,403,892, 5,397,839, 5,397,832, 5,349,005, 5,300,573, 5,290,886, 5,177,147, 5,157,081, 5,100,947, 5,086,121, 5,081,179, 5,073,597, 5,070,111, 5,051,478, 5,051,477, 5,028,662, and U.S. RE 035398. SANTOPRENE® is known to consist of a combination of butyl rubber and ethylene-propylene. KRATON® thermoplastic elastomers made by the Shell Oil Corporation, DYNAFLEX® thermoplastic elastomers, and VERSAFLEX® thermoplastic elastomer alloys distributed by GLS Corporation of McHenry, Ill. can also be suitable for use. Further, the material compositions taught in both U.S. Pat. No. 6,342,544 B1 and U.S. Pat. No. 6,367,167 granted to Krstic et al. and assigned to Nike, Inc. can also be suitable for use, and these patents are hereby incorporated by reference herein.

[0589] The backing 30 portion of the outsole 43 can be made of a formulation of a thermoplastic material such as nylon, polyurethane, or SANTOPRENE® that is relatively firm relative to the ground engaging portion 53 of the outsole 43. For example, a polyurethane or SANTOPRENE® material having a hardness between 35-75 Durometer Asker C could be used on the ground engaging portion 53 of the outsole 43, whereas a polyurethane or SANTOPRENE® material having a hardness between 75-100 Durometer on the Shore A or D scales could be used to make the backing 30 of outsole 43. A polyurethane backing 30 can be bonded to a polyurethane ground engaging portion 53 of outsole 43 or other material, or alternately, a SANTOPRENE® backing can be bonded to a SANTOPRENE® ground engaging portion 53 of outsole 43. This can be accomplished by dual injection molding, or over-molding of the like materials.

[0590] One advantage when using homogenous materials for the two portions of the outsole 43 concerns the affinity of like materials for effectively bonding together. Another advantage in using homogenous materials for the two portions of the outsole 43 concerns the “green” or environmentally friendly and recyclable nature of the component at the end of its service life. It is possible for the spent homogenous outsole 43 component including the backing 30 and ground engaging portion 53 to be recycled by the footwear manufacturer or by a third party, e.g., the outsole 43 can be re-ground into pieces and be thermoformed to make a portion of a new outsole 43 component. Further, the relative absence of adhesives in the manufacture of the outsole components and article of footwear taught in the present invention also makes for a “green” or environmentally friendly product. In contrast, conventional articles of footwear are commonly manufactured with the extensive use of adhesives for bonding a foam midsole to an upper and outsole. These adhesives are commonly non-environmentally friendly and can pose health hazards, and the resulting article of footwear cannot be so easily disassembled or recycled at the end of its service life. Moreover, the process associated with making conventional foam materials in making a midsole, and the blowing agents used therein, can be non-environmentally friendly and relatively energy inefficient as compared with conventional injection molding of thermoplastic materials, or the use of light cure materials and methods, as taught in the applicant's co-pending U.S. patent application Ser. No. 08/862,598 entitled “Method of Making a Light Cure Component For Articles of Footwear,” hereby incorporated by reference herein. For example, instead of using large presses imparting both heat and pressure upon compression molds for effecting the cure of a midsole or outsole component over perhaps a seven minute cycle time, injection molding equipment and light cure technology can be used to reduce the cycle times to perhaps fractions of a second with relative energy efficiency and little or no waste product in a relatively environmentally friendly manufacturing environment. Accordingly, manufacturing can be located in the United States, or otherwise closer to the intended market.

[0591] It is also possible for heterogeneous materials to be used in making the backing 30 and ground engaging portion 53 of the outsole 43. For example, Advanced Elastomer Systems has developed a formulation of SANTOPRENE® which is capable of bonding to nylon. See also U.S. Pat. Nos. 5,709,954, 5,786,057, 5,843,268, and 5,906,872 granted to Lyden et al. and assigned to Nike, Inc. which relate to chemical bonding of rubber to plastic materials in articles of footwear, all of these patents hereby incorporated by reference herein Further, in an alternate embodiment of the present invention, the backing 30 can simultaneously comprise at least a portion of the spring element 51 of the article of footwear 22, as shown in FIG. 16. In addition, the outsole 43 can also include desired lines of flexion 54. The following patents and some of the prior art recited therein contain teachings with respect to lines of flexion 54 in articles of footwear such as grooves, and the like: U.S. Pat. Nos. 5,384,973, 5,425,184, 5,25,964, 5,709,954, 5,786,057, 4,562,651, 4,837,949, and 5,024,007, all of these patents being hereby incorporated by reference herein.

[0592] The use of a relatively soft elastomeric material having good dampening characteristics on the ground engaging portion 53 of an outsole 43 can contribute to enhanced attenuation of the shock and vibration generated by impact events. Relatively soft elastomeric materials having good dampening characteristics tend to have inferior abrasion and wear characteristics, and this can pose a practical limitation on their use in conventional articles of footwear constructed with the use of adhesives having non-renewable outsoles. However, the use of relatively soft elastomeric materials having good dampening characteristics does not pose a practical problem with respect to the preferred article of footwear 22 taught in the present application since the outsole 43 can be easily renewed and replaced. Accordingly, the preferred article of footwear 22 can provide a wearer with enhanced cushioning effects relative to many conventional articles of footwear.

[0593] The spring element 51 can be made of a resilient material such as metal, and in particular, spring steel or titanium. Titanium is widely used in the aerospace and automotive industries in part due to its excellent strength to weight ratio and durability. Titanium materials are available in three general categories depending upon their alloy content: alpha, that is, a material having a close packed hexagonal atomic arrangement, alpha/beta, and beta, that is, a material having a body centered cubic atomic arrangement, The preferred titanium alloys for use in a spring element 51 are those which can be characterized either as alpha/beta, or beta. Examples of suitable alpha/beta, or beta titanium alloys include “15-3” and “6-4” which can be obtained from TIMET®, Titanium Metals Corporation, of 403 Ryder Avenue, Vallejo, Calif. 94590, and also from President Titanium of Hanson, Mass. 02341.

[0594] The spring element 51 can alternately be made of a thermoplastic material, or alternately, a preferred fiber composite material. Glass fiber, aramid or KEVLAR® fiber, boron fiber, or carbon fiber composite materials can be used individually, or in partial or complete combination. Glass fiber composite materials are generally available at a cost of about $5.00 per pound, whereas carbon fiber materials are generally available at a cost of about $8.00-$14.00 per pound. Glass fiber composite materials generally exhibit a lower modulus of elasticity or flexural modulus, thus less stiffness in bending as compared with carbon fiber materials, but can generally withstand more severe bending without breaking. However, the higher modulus of elasticity of carbon fiber composite materials can provide greater stiffness in bending, a higher spring rate, and reduced weight relative to glass fiber composite materials exhibiting like flexural modulus. Blends or combinations of glass fiber and carbon fiber materials are commonly known as hybrid composite materials.

[0595] Carbon fiber composite materials can be impregnated or coated with thermoplastic materials or thermoset materials. The modulus of elasticity or flexural modulus of some finished thermoplastic carbon fiber composite materials can be lower than that of some thermoset carbon fiber composite materials. For example, a sample of thermoplastic carbon fiber composite material having a relatively broad weave can have a flexural modulus in the range between 10-12 Msi, and in the range between 5-6 Msi in a finished part, whereas a “standard modulus” grade of thermoset impregnated unidirectional carbon fiber composite material can have a flexural modulus in the range of 33 Msi and in the range between 18-20 Msi in a finished part. Also available are “intermediate modulus” carbon fiber composite materials at approximately 40 Msi and “high modulus” carbon fiber composite materials having a flexural modulus greater than 50 Msi and possibly as high as approximately 100 Msi. Accordingly, in order the achieve a desired flexural modulus or stiffness value, a thicker and heavier part made of a thermoplastic carbon fiber composite material can be required, that is, relative to a thermoset impregnated unidirectional carbon fiber composite material

[0596] Impregnated carbon fiber composite materials are commonly known as “prepreg”materials. Such materials are available in roll and sheet form and in various grades, sizes, types of fibers, and fiber configurations, but also with various resin components. Various known fiber configurations include so-called woven, plain, basket, twill satin, unidirectional, multi-directional, and hybrids. Prepreg carbon fiber composite materials are available having various flexural modulus, and generally, the higher is the modulus then the more expensive is the material. A standard modulus unidirectional prepreg peel-ply toughened carbon fiber composite material such as C2000, 33550, 150 GSM, having a 35 percent resin content, or alternately, “quick-cure” 2510 made by Zoltek Materials Group, Inc. of San Diego, Calif. 97121 can be suitable for use. This prepreg material can have a thickness of 0.025 mm or 0.01 inches including the peel-ply backing and in the range between 0.13-0.15 mm or 0.005 inches without. It is therefore relatively easy to predict the number of layers required in order to made a part having a known target thickness, but one should also allow for a nearly 10 percent reduction in thickness of the part due to shrinkage during the curing process. The cost in bulk of a suitable unidirectional 33 Msi thermoset standard modulus carbon fiber composite material having a weight of approximately 150-300 grams per square meter made and distributed by Zoltek Materials Group, Inc. is presently approximately in the range between $8.00 and $9.00 per pound, and one pound yields approximately one square meter of material

[0597] The required thickness of a spring element 51 and any possible sub-components can vary considerably depending upon, e.g., the materials being used, the construction and processing methods being used, the overall design and configuration of a particular part, the fastener(s) possibly being used, the intended activity or particular application, and also the weight, biomechanical technique, and characteristic running speed or velocity of an individual wearer. Nevertheless, the following information can serve as a broad guideline both when making and selecting a spring element 51 and any possible sub-components for use in an article of footwear. The superior spring element can have a thickness approximately in the range between 0.5-10.0 mm The superior spring element can include an anterior spring element having a thickness approximately in the range between 0.5-2.5 mm, and in particular, in the range between 1.0-1.75 mm. It can be advantageous that the anterior spring element 48 maintain a thickness that is not much less than 1 mm in order to well distribute point loads, enhance robustness of the part, and to provide a noticeable performance enhancement. The superior spring element or posterior spring element can have a thickness in the rearfoot area approximately in the range between 1-10 mm, but when formed in a three dimensional cupped shape including a heel counter, can have a lesser thickness in the range between 1-5 mm The inferior spring element can have a thickness approximately in the range between 3-10 mm.

[0598] The following more specific guidelines relate to an article of footwear including a spring element having relatively short lever arms which can provide approximately 10 mm of deflection generally resembling the embodiment represented in drawing FIGS. 1-4. The required thickness of the superior spring element 47 or anterior spring element 48 in the forefoot area 58 of an article of footwear intended for use in running when using standard modulus 33 Msi thermoset unidirectional prepreg carbon fiber composite material is then normally approximately in the range between 1.0-1.25 mm for an individual weighing 100-140 pounds running at slow to moderate speeds, approximately in the range between 1.25-1.50 mm for an individual weighing 140-180 pounds running at slow to moderate speeds, and in the range between 1.5-1.75 mm for an individual weighing 180-220 pounds running at slow to moderate speeds. When running at higher speeds, e.g., on a track and field surface, individuals generally prefer a thicker and stiffer plate relative to that selected for use at slow or moderate speeds. The perceived improvement in running economy can be on the order of at least one second over four hundred meters which corresponds to approximately two to three percent improvement in athletic performance. The superior spring element 47 or anterior spring element 48 can store energy when loaded during the latter portion of the stance phase and early portion of the propulsive phase of the running cycle, and then release that energy during the latter portion of the propulsive phase. A spring element can provide not only deflection for attenuating shock and vibration associated with impact events, but can also provide a relatively high level of mechanical efficiency by possibly storing and returning in excess of 70 percent of the energy imparted thereto. Accordingly, the spring to dampening ratio of the material of which the spring element is made can be expressed as being equal to or greater than 70/30 percent. In fact, a preferred unidirectional carbon fiber composite material or spring titanium material can return in excess of 90 percent of the energy imparted thereto during the materials test associated with ASTM 790. In contrast, most conventional prior art athletic footwear soles including foam midsoles and rubber outsoles have a spring to dampening ratio somewhere between 40 and 60 percent. The preferred article of footwear 22 can then afford a wearer with greater mechanical efficiency and running economy than most conventional prior art athletic footwear.

[0599] Further, unlike the conventional foam materials used in prior art articles of footwear such as ethylene vinyl acetate which can become compacted and take a compression set, the spring elements 51 used in the present invention are not substantially subject to compression set degradation due to repetitive loading. The degradation of conventional foam materials can cause injury to a wearer, as when a broken down midsole results in a wearer's foot being unnaturally placed in a supinated or pronated position as opposed to a more neutral position, or when a compacted foam midsole in the forefoot area 58 causes a wearer's metatarsals to drop out of normal orientation or to unnaturally converge. Further, the quality of cushioning provided by conventional foam materials such as ethylene vinyl acetate or polyurethane rapidly degrades as the material becomes compacted and takes a compression set. In contrast, the spring elements 51 taught in the present invention do not substantially suffer from these forms of degradation, rather provide substantially the same performance and geometric integrity after extended use as when new. Given an article of footwear including removable and replaceable components, in the event of a fatigue or catastrophic failure of a spring element, the damaged part can simply be removed and replaced.

[0600] Again, given an article of footwear including a spring element generally resembling the embodiment represented in drawing FIGS. 1-4, the required thickness of a superior spring element 47, or posterior spring element 49 for the rearfoot area 68 of an article of footwear intended for running use when using standard modulus 33 Msi thermoset uni-directional prepreg carbon fiber composite material is approximately in the range between 2.0-5.0 mm, and in particular, is approximately in the range between 2.75-3.25 mm for an individual weighing in the range between 100-140 pounds, approximately in the range between 3.25-3.75 mm for an individual weighing in the range between 140-180 pounds, and approximately in the range between 3.75-4.25 for an individual weighing between 180-220 pounds. It can be advantageous for the sake of robustness that the thickness of the inferior spring element 50 be at least equal to or greater than that of the corresponding superior spring element 47 or posterior spring element 49 in the rearfoot area 68, as the inferior spring element 50 has a more complex curved shape and is subject to direct repetitive impact events. Accordingly, given an article of footwear including a spring element generally resembling the embodiment represented in drawing FIGS. 1-4, the required thickness of the inferior spring element 50 when using standard modulus 33 Msi thermoset unidirectional prepreg carbon fiber material is approximately in the range between 2.0-5.0 mm, and in particular, is approximately in the range between 2.75-3.25 mm for an individual weighing in the range between 100-140 pounds, approximately in the range between 3.25-3.75 mm for an individual weighing in the range between 140-180 pounds, and approximately in the range between 3.75-4.25 for an individual weighing between 180-220 pounds.

[0601] Different individuals can have different preferences with respect to the thickness and stiffness of various spring element components regardless of their body weight, and this can be due to their having different running styles or different habitual average running speeds. During normal walking activity the magnitude of the loads generated are commonly in the range between one to two body weights, whereas during normal running activity the magnitude of the loads generated are commonly in the range between two to three body weights. Accordingly, the flexural modulus of a spring element for use in an article of footwear primarily intended for walking can be reduced relative to an article of footwear intended for running, thus the thickness and/or stiffness of the spring element can be reduced. During a lateral movement and jumping sport such as basketball, the loads generated can be much higher and in the range between 2.5 and 10 body weights. Accordingly, greater stiffness and/or thickness can be required of a spring element 51 and any sub-component parts. As result it can sometimes be advantageous to introduce an additional cushioning medium such as a fluid-filled bladder and/or a foam material between a superior spring element 47 or posterior spring element 49 and an inferior spring element 50, and also between a superior spring element 47 or anterior spring element 48.1, and an anterior spring element 48.2.

[0602] When making spring elements using carbon fiber composite material, it is important to recognize that relatively slight variations in the configuration or design can have both substantial and subtle effects upon the exhibited stiffness, service life, and overall performance of the component. For example, consider the long bow, versus the recurve bow configuration used in archery. These two shapes provide different stiffness characteristics when the bow is being drawn, and also when the arrow is released. For example, when the inferior spring element 50 is made in a sharper curved shape it can exhibit greater stiffness and a different stress/strain curve, that is, relative to when it is made in a more gentle curved configuration.

[0603] Again, given an article of footwear including a spring element generally resembling the embodiment represented in drawing FIGS. 1-4, the following constitutes an approximate guideline regarding the required thickness and stiffness of a superior spring element 47 or anterior spring element 48 made of standard modulus 33 Msi unidirectional carbon fiber composite material for use in the forefoot area 48 of a running shoe given a wearer's body weight and common perception. Again, much depends on an individual's body weight, running technique, speed, and the intended application. For example, an individual having a given body weight who happened to be a heavy heel striker would likely select an anterior spring element 48 having the next highest stiffness value. Likewise, an individual who habitually runs at a faster pace than another individual having a similar body weight and running technique might also select an anterior spring element 48 having the next highest stiffness value. Nevertheless, Table 1 shown below can provide guidance to runners making selections regarding a suitable spring element 51.

[0604]

TABLE 1
Runner's Body Weight (pounds)
Thickness (mm)	100	120	140	160	180	200	220
.75	S	VS	VS	VS
1.0	M	S	S	S	VS	VS
1.25	H	M	M	M	S	S	VS
1.50	VH	H	H	M	M	M	S
1.75		VH	VH	H	H	M	M
2.0				VH	VH	H	H
2.25						VH	VH
Key to Abbreviations
VS = Very Soft = Suitable For Long Slow Distance (LSD) Running Slower than 7:00 minutes/mile.
S = Soft = Suitable For Running 6:00 minutes/mile.
M = Medium = Suitable For Running sub-5:00 minutes/mile.
H = Hard = Suitable For Running sub-60 seconds/400 meters.
VH = Very Hard = Suitable For Short Sprints, and Jumps.

[0605] Again, regarding the rearfoot area 68 of the superior spring element 47 or posterior spring element 49, the thickness of the part can vary considerably depending upon whether a relatively flat configuration, or alternately, a cupped shape anatomical configuration which possibly includes a curved midfoot area 67 including longitudinal and transverse arch support, medial and lateral side stabilizers, or a heel counter 24 is incorporated therein. Given a three dimensional cupped or anatomical shaped posterior spring element 49 including a heel counter, and an individual weighing between 100-200 pounds the minimum thickness required to achieve the desired robustness is believed to be approximately in the range between 1.0 and 1.5 mm. However, when a fastener 29 is used to affix the inferior spring element 50 to the superior spring element 47 or posterior spring element 49, even with the presence of a large washer or flange, a fastener 29 can still impart a relatively large point load, thus a minimum thickness of 2.5 mm in the area near the position of the fastener 29 can be required in order to ensure robustness.

[0606] Regardless, the upwardly extending portions of a posterior spring element 49 forming a heel counter 24 and also the anterior edge of the part can generally be made to have a thickness in the range between 0.5-2.0 mm. It is believed to be advantageous for the purposes of commercialization to over-engineer the part with respect to load tolerance and robustness and to make the inferior side of the posterior portion of a superior spring element 47 or a posterior spring element 49, in not more than three or four different thickness: e.g., approximately 2.0 mm for the range between 100-140 pounds body weight; approximately 2.5 mm for the range between 140-180 pounds body weight; and, approximately 3.0 mm for the range between 180-220 pounds body weight.

[0607] It can be helpful to provide guidance regarding the stiffness characteristics associated with various portions of a spring element 51, e.g., S (soft), M (medium), and H (hard), VH (very hard) UH (ultra hard), or to otherwise identify suitable performance criteria by specific event, player position, and the like. One way of expressing the relationship between superior spring elements 47 or posterior spring elements 49 having a three dimension cupped shape including a heel counter which are made in one of three different thickness in the rearfoot area 68, and the possible use of five different alternate thickness in the forefoot area 58 of the superior spring element 47 or an anterior spring element 48 in a running shoe suitable for use in track and field is shown in Table 2 below.

[0608]

TABLE 2
Runner's Weight &	Runner's Weight &
Posterior Spring	Anterior Spring
Thickness in	Thickness in
Rearfoot Area	Forefoot Area (mm)
(3D Part)(mm)	1.0	1.25	1.5	1.75	2.0
2.0 (100-140 lbs)	LSD	5k-10k	800/1500	Sprints
2.5 (140-180 lbs)	LSD	5k-10K	800/1500	Sprints	Sprints
3.0 (180-220 lbs)	LSD	LSD	5k-10k	800/1500	Sprints

[0609] Regarding the amount of deflection in the rearfoot area 68 associated with the superior spring element 47 or posterior spring element 49, if and when the superior spring element 47 or posterior spring element 49 is made in a three dimensional cupped shape possibly including a heel counter 24, then not much deflection will take place, e.g., normally something in the range between 0-2.0 mm. It is important to recognize that if the superior spring element 47 or posterior spring element 49 is made in a three dimensional cupped shape including a heel counter that only permits something in the range between 0-2.0 mm of deflection, then this can place a larger load and requirement for deflection upon the inferior spring element 50. Accordingly, all things being equal, the inferior spring element 50 could then have to be made thicker and/or stiffer. Nevertheless, if and when the superior spring element 47 or posterior spring element 49 is substantially flat and planar, and the inferior spring element 50 is curved, but both parts have about the same thickness, then the inferior spring element 50 will generally still exhibit the most deflection. However, the superior spring element 47 or posterior spring element 49 will also account for a portion of the total deflection. In the abstract, if the parts are engineered so as to permit 10 mm of total deflection, then the inferior spring will normally account for at least half and perhaps nearer to three quarters of the deflection, before the two parts would meet and “bottom out” the mechanical system. Here, a great deal depends upon the design and manufacture of the parts, the application, and the wearer's body weight and technique.

[0610] Given a running shoe used in a typical linear running motion, even 4-6 mm of deflection of the superior spring element 47 or posterior spring element 49 in the rearfoot area 68 will not pose a biomechanical or stability problem provided that the article of footwear is designed properly. It should be noted that the fat pad on the human heel is known to commonly deflect approximately in the range between 8-10 mm, and also the longitudinal arches of many individuals are known to commonly deflect in the range between 2-6 mm. Moreover, in existing conventional articles of footwear including foam midsoles equal to or greater than 4-6 mm of deflection commonly takes place on both the top and bottom sides of the sole during a rearfoot impact event.

[0611] A question can be raised concerning the possibility of 4-6 mm of deflection taking place at the lateral rear corner, that is, deflection having a torsional component. If a line 80 mm in length is drawn representing the width of the bottom net of the outsole 43 of a typical running shoe sole in the rearfoot area 68, and then a line 6 mm high is drawn perpendicular to and intersecting the line having a length of 80 mm at the end on the lateral side, the resulting angle as measured from the opposite side of the line having a length of 80 mm is only approximately five degrees. This does not degrade stability since the feet of most individuals are normally supinated approximately 7-8 degrees upon footstrike when running barefoot on grass, and substantial rotative movements commonly take place between the rearfoot and forefoot areas of an individual's foot during running activity. Further, the average runner commonly pronates approximately 7-8 degrees when running barefoot on grass, but double that magnitude of pronation can be associated with running in conventional prior art articles of footwear including foam midsoles. However, both the rate and magnitude of pronation can often be reduced by using an article of footwear made according to the present invention, that is, relative to a conventional prior art article of footwear. Moreover, it can possibly be advantageous to engineer an article of footwear including a spring element 51 intended for running so as to approximate the magnitude of supination upon footstrike, and also the subsequent magnitude and rate of pronation commonly observed when individuals run barefoot on natural grass. Nevertheless, it can be readily understood that the design and engineering of an article of footwear including a spring element 51 can have different requirements for other sport applications which include lateral and random movements.

[0612] Again, the required thickness of the inferior spring element 50 will depend in part upon whether the superior spring element 47 or posterior spring element 49 is contributing to deflection, and by how much, the design and composition of the inferior spring element 50, but also a wearer's body weight, biomechanical technique, and speed. For example, given an article of footwear including a spring element generally resembling the embodiment represented in FIGS. 1-4 which provides approximately 10 mm of total deflection, and a generally planar superior spring element 47 or posterior spring element 49 making a contribution to deflection of less than or equal to 5 mm, and an individual running at slow to moderate speeds, the approximate required thickness of an inferior spring element 50 made of standard modulus 33 Msi carbon fiber composite material having a curved configuration and a diagonal flexural axis 59 is shown in Table 3 provided below.

[0613] If and when the superior spring element 47 or posterior spring element 49 has a three dimensional shape including a heel counter and therefore makes little or no contribution to deflection, that is, deflection in the range between 0-2.0 mm, then the inferior spring element 50 will generally need to be approximately at least 0.25 -0.5 mm thicker in order to effectively manage the loading associated with greater deflection so as to not exceed approximately 60-66 percent of the inferior spring element's 50 maximum engineered loading capacity. This percentage represents an approximate threshold regarding the capability of carbon fiber composite materials to withstand cycling loading for hundreds of thousands or millions of cycles.

[0614] It is important to note that as the flexural axis 59 is rotated from the transverse axis 91 orientated at 90 degrees to the longitudinal axis 69 and towards a 45 degree angle, the effective length of the flexural axis 59 and stiffness of the inferior spring element 50 can be increased. Further, when the superior spring element 47 or posterior spring element 49 and the inferior spring element 50 are being fabricated, it can be advantageous to position some of the layers of the carbon fiber material both consistent with and perpendicular to the orientation of the flexural axis 59, since this area can function as a fulcrum point and be associated with high local loading.

[0615] The length of the effective lever arms 60 and 61 of the superior spring element 47 or posterior spring element 49, and the inferior spring element 50 on the medial and lateral sides will also influence the stiffness of the larger spring element 51. Accordingly, it can be readily understood that scalar effects can be present with respect to widely varying sizes of articles of footwear. Again, given an article of footwear including a spring element generally resembling the embodiment represented in FIGS. 1-4 providing approximately 10 mm of deflection and made of standard modulus 33 Msi carbon fiber composite material, the approximate required thickness of an inferior spring element 50 as a function of the body weight of a runner, and also the type of superior spring element 47 or posterior spring element 49 being used is shown in Table 3 below.

[0616]

	TABLE 3
	Superior/Posterior	Superior/Posterior
	Spring Deflects = 5 mm	Spring Deflects 0-2 mm
	Thus, Inferior Spring	Thus, Inferior Spring
Body Weight (lbs)	Thickness (mm)	Thickness (mm)
100	2.5-2.75	2.75-3.25
120	2.75-3.0	3.0-3.5
140	3.0-3.25	3.25-3.75
160	3.25-3.50	3.5-4.0
180	3.5-3.75	3.75-4.25
200	3.75-4.0	4.0-4.5
220	4.0-4.25	4.25-4.75

[0617] When the superior spring element 47 consists of a single part, the thickness can vary and be tapered from the posterior side 34 to the anterior side 33, that is, the part can gradually become thinner moving in the direction of the anterior side 33. This can be accomplished by reducing the number of layers during the building of the part and/or with the use of compressive force during the molding or curing process. When the superior spring element 47 consists of two parts, e.g., an anterior spring element 48 and a posterior spring element 49, the parts can be made in different thickness. Alternately, the posterior spring element 49 can be made of a higher modulus material having a given thickness, and the anterior spring element 48 can be made of a lower modulus material having the same thickness, thus the two parts can possibly have the same thickness but nevertheless provide different and desired spring and dampening characteristics.

[0618] Alternately, the number of fiber composite layers, the type of fiber and resin composition of the layers, the inclusion of a core material, and the geometry and orientation of the layers, can be varied so as to create areas of differential stiffness in a spring element 51. For example, the inferior spring element 50 can project from the superior spring element 47 with the flexural axis 59 orientated consistent with a transverse axis, that is, at approximately 90 degrees with respect to the longitudinal axis 69 provided that the aforementioned variables concerning the fiber composite layers are suitably engineered so as to render the medial side 35 of the inferior spring element 50 approximately 2-3 times stiffer than the lateral side 36, that is, in an article of footwear intended for walking or running activity.

[0619] Further, the configuration of a spring element 51, and in particular, an inferior spring element 50 having an flexural axis 59 orientated at approximately 90 degrees with respect to the longitudinal axis 69, can be configured so as to provide differential stiffness. For example, a portion of a spring element 51 can include transverse or longitudinal slits, notches, openings, a core material, or reduced thickness so as to exhibit areas of differential stiffness, as shown in FIG. 10. Several configurations and methods for achieving differential stiffness in the midfoot area 67 or rearfoot area 68 of an article of footwear are recited in U.S. Pat. No. 5,875,567, this patent being hereby incorporated by reference herein. However, the relatively sharp portion of the spring element that is shown projecting beyond the medial side of the sole in U.S. Pat. No. 5,875,567 could possibly result in injury to the medial side of a wearer's opposite leg during running. Further, given the common orientation of the foot of a wearer who would be characterized as a rearfoot striker during footstrike, an inferior spring element 50 having an flexural axis 59 orientated consistent with transverse axis 91, that is, at 90 degrees with respect to the longitudinal axis 69, is generally not so advantageously disposed to receive repetitive loading and exhibit robustness during its service life relative to an inferior spring element 50 having an flexural axis 59 deviated from the transverse axis 91 in the range between 10 and 50 degrees, as shown in FIGS. 9 and 10. In this regard, the foot of a wearer characterized as a rearfoot striker is normally somewhat dorsiflexed, supinated and abducted during footstrike, as recited and shown in U.S. Pat. Nos. 5,425,184, and 5,625,964, these patents being hereby incorporated by reference herein Accordingly, given an average individual having normal biomechanics who would be characterized as a rearfoot striker, it can be advantageous for the flexural axis 59 of the inferior spring element 50 to be deviated from the transverse axis 91 in the range between 10-30 degrees in footwear intended for walking or running. However, the flexural axis 59 of an inferior spring element 50 can be deviated from the transverse axis 91 in the range between 30-50 degrees in footwear intended for use by individuals who tend to more substantially pronate during the braking and stance phases of the gait cycle. Other teachings having possible merit relating to differential stiffness in the rearfoot area of an article of footwear include, e.g., U.S. Pat. Nos. 4,506,462, 4,364,189, 5,201,125, 5,197,206, and 5,197,207, all of these patents hereby being incorporated by reference herein.

[0620] In order to make carbon fiber composite spring elements, it can be advantageous to create a form or mold. The form or mold can be made of wood, composite material, metal, and the like. For example, prototype forms or molds can be made of thin sheets of stainless steel which can be cut and bent into the desired configurations. The stainless steel can then be treated with a cleaner and appropriate release agent. For example, the stainless steel can be washed with WATERCLEAN and then dried, then given two coats of SEALPROOF sealer and dried, and finally given two coats of WATERSHIELD release agent and dried, all of these products being made by Zyvax, Inc. of Boca Raton, Fla., and distributed by Technology Marketing, Inc. of Vancouver, Wash., and Salt Lake City, Utah. A “prepreg” uni-directional carbon fiber composite material including a peel-off protective layer that exposes a self-adhesive surface can then be cut to the approximate shapes of the desired spring element by a razor blade, scissors, cutting die, water jet cutter, or automatic cutting machine. Suitable carbon fiber composite materials for use include F3(C) 50K made by FORTAFIL, AS4C made by “EXCEL, T300 made by TORAY/AMOCO, and in particular, ZMG-2000-Z346-150-35-24” which is a 150 GSM material including a toughened epoxy with a 35 percent resin content made by Zoltek Materials Group, Inc., and the like. The individual layers of carbon fiber composite material can have a thickness in the range between approximately 0.13-0.15 mm or 0.005 inches and be affixed to one another to build the desired thickness of the spring elements, but allowing for a reduction of approximately 10 percent due to shrinkage which commonly takes place during the curing process. The individual layers can be alternated in various orientations, e.g., some can be orientated parallel to the length of the desired spring element, and others inclined at 45 degrees to the left or right, or at 90 degrees. The result can be a quasi-isotropic fiber composite material, that is, one having a relatively homogenous flexural modulus in all directions. However, the flexural modulus or stiffness in bending exhibited by the spring element in various orientations can be specifically engineered by varying the number, type, and orientation of the fiber composite layers.

[0621] Once the spring element components have been built by adhering the desired number, type, and orientation of glass or carbon fiber composite layers together, the spring element can be rolled or placed under pressure and applied to the stainless steel prototype form or mold. When making prototype spring elements, the carbon fiber composite lay-up including the stainless steel form or mold can be wrapped in a peel ply or perforated release film such as Vac-Pak E 3760 or A 5000 Teflon® FEP, then wrapped in a bleeder such as A 3000 Resin Bleeder/Breather or RC-3000-10A polyester which will absorb excess resin which could leach from the spring elements during curing. This assembly can then be enclosed in a vacuum bagging film, e.g., a Vak-Pak® Co-Extruded Nylon Bagging Film such as Vac-Pak HS 800 and all mating edges can be sealed with the use of a sealant tape such as Schnee Morehead vacuum bag tacky tape, or RAP RS200. A vacuum valve can be installed in functional relation to the vacuum bagging film before the vacuum bag is completely sealed. The vacuum valve can be subsequently connected to an autoclave vacuum hose and a vacuum pump, and the assembly can be checked for leaks before placing it in an oven for curing. The entire assembly, while under constant vacuum pressure, can then be placed into an oven and heated at a temperature of approximately 250 degrees Fahrenheit for one to two hours in order to effect setting and curing of the carbon fiber composite spring elements. Upon removal from the oven and cooling, the vacuum bag can be opened and the cured carbon fiber composite spring elements can be removed from within the bleeder and the peel ply or release film, and separated from the stainless steel form or mold. The spring element parts can then possibly be cut or trimmed with a saw, a grinding wheel, a sander, a CNC machine, or with the use of water jet cutting equipment. The fasteners 29 can then be affixed and the spring element installed in functional relation to the upper and outsole of a prototype article of footwear.

[0622] The method of making fiber composite materials in a production setting differs depending upon whether thermoplastic or thermoset materials are being used. For example, thermoplastic carbon fiber composite materials including their resin coatings are commonly available in flat sheet stock. Parts can then be cut from these sheets using water jet cutting equipment. These parts can then be preheated for a short time in an oven in order to reach a temperature below, but yet relatively close to the melt point of the thermoplastic material, thus rendering the part moldable. Production compression molds are commonly milled from aluminum, then polished and treated with a non-stick coating and release agent. The cost of a single aluminum production compression mold is approximately $2,500. The heated thermoplastic carbon fiber composite parts can then be placed into a relatively cold compression mold and subjected to pressure as the part is simultaneously caused to set and cool. The parts can then be removed and inspected for possible use. One manufacturer of thermoset fiber composite parts is Performance Materials Corporation of 1150 Calle Suerte, Camarillo, Calif. 93012.

[0623] The production method and process is different when a thermoset carbon fiber composite unidirectional prepreg material is being used to make a desired part. The uncured layered thermoset part can be placed into an aluminum compression mold which has been preheated to a desired temperature. The mold is closed and the part is then subjected to both heat and pressure. In this regard, the set and cure time of thermoset fiber composite materials is temperature dependent. Generally, the set and cure time for thermoset parts will be about one hour given a temperature of 250 degrees Fahrenheit. However, it is often possible for the same thermoset parts to reach their gel state and take a set, whereupon the shape of the part will be stable, in about one half hour given a temperature of 270 degrees Fahrenheit, in about fifteen minutes given a temperature of 290 degrees Fahrenheit, or in about seven minutes given a temperature of 310 degrees Fahrenheit. Having once reached their gel state and taken a set, the thermoset parts can then be removed from the mold. The parts can later be placed in an oven and subjected to one to two hours of exposure to a temperature of 250 degrees Fahrenheit in order to complete the curing process. Moreover, Zoltek Materials Group, Inc. of San Diego, Calif. makes a “quick cure” thermoset material identified by their product code number 2510 which can completely cure in ten minutes given a mold temperature of 250 degrees Fahrenheit, and perhaps even faster at higher temperatures.

[0624] An alternate method of making thermoset carbon fiber composite spring element components involves making and using a single sided mold having sufficient width to encompass at least one part along the x axis, but the mold can then extend along the y axis for many feet, or vice-versa. For example, the mold can be made of 7075 grade aluminum which can be purchased from Metals USA, Specialty Metals Northwest, Inc. at 3400 S.W. Bond Avenue, in Portland, Oreg. The mold can have a have a width of 16 inches, a length of 30 inches, and maximum thickness of 1¼ inches, and be machined to provide a desired configuration using CNC equipment. Accordingly, a relatively long lay-up of carbon fiber material can be placed upon the mold, vacuum bagged, and then cured in an autoclave. For example, ZMG-2000-Z346-150-35-24″ which is a 150 GSM prepreg carbon fiber material including a toughened epoxy with a 35 percent resin content made by Zoltek Materials Group, Inc. can be used. A thicker material such as 300 GSM prepreg carbon fiber material can be used alone, or alternately, in combination with a 150 GSM material in order to more rapidly build up the thickness of the desired part. A large number of individual components can then be cut from the resulting cured sheet of carbon fiber material For example, approximately seven full-length superior spring element 47 parts can be obtained from a sheet of carbon fiber composite material formed upon mold having the size recited above. Alternately, approximately fourteen inferior spring elements 50 can be obtained from a sheet of carbon fiber composite material formed upon a mold having the size recited above. The individual parts can be cut with a saber saw, a CNC machine using a vacuum fixture for holding the cured sheet of carbon fiber composite material, or with a multi-dimensional water jet cutter. A provider of water jet cutting services is Hegar Manufacturing of 15600 S.E. FOR/MOR, Clackamas, Oreg. A superior spring element or anterior spring element having a planar configuration, or alternately, a curved shape can be made by this method. Moreover, an inferior spring element having more dramatic curved shape can be made by this method.

[0625] An alternate method of making carbon fiber composite parts involves using an injection mold. An uncured carbon fiber material which may or may not already be impregnated with a resin can be placed into an injection mold, and resin can then be injected under pressure and subsequently cured to form a finished part. Alternately, a resin containing short or long glass, carbon, or boron fibers can be injected into a mold and caused to set. The compression and injection mold methods of making fiber composite parts can be advantageous for use when attempting to make components having multiple complex curved shapes. Manufacturers of thermoset fiber composite parts include All Composites of 3206 232nd Street, East Spanayay, Wash. 98387, and Quatro Composites of 12544 Kirkham Court, Number 16, Poway, Calif. 92064.

[0626] Alternative methods of making fiber composite parts can include the use of light cure technology, other forms of compression or injection molding, reaction injection molding, and also pulltrusion. Compression molding, injection molding, and reaction injection molding have been widely used in the automotive industry, e.g., the body of the Corvette largely consists of fiber composite construction. Thermoplastic materials, or alternately, thermoset materials including polymers, resins, or epoxies which are rubber toughened that further include glass fiber, aramid fiber, carbon fiber, or boron fiber materials, and the like, can possibly be used. For example, Dow Chemical Company of Midland, Mich. makes SPECTRUM® reaction moldable polymer which has been used to make automobile body parts, and LNP Engineering Plastics of Exton, Pa. makes THERMOCOMP® and VERTON® thermoplastic materials which can include long carbon fibers. Further, PPG of Pittsburgh, Pa., Corning, of Coming, N.Y., and Vetrotex of Valley Forge, Pa., are makers of electrical and structural grade fiberglass products.

[0627] FIG. 2 is a top view showing the superior side 37 of the article of footwear 22 shown in FIG. 1. Shown are the tip 25, vamp 52, insole 55, anterior side 33, posterior side 34, medial side 35, and lateral side 36 of the upper 23 of the article of footwear 22. Also shown is the forefoot area 58, midfoot area 67, rearfoot area 68, and position approximately corresponding to the weight bearing center of the heel 57.

[0628] FIG. 3 is a bottom view showing the inferior side 38 of the article of footwear 22 shown in FIG. 1. Shown is an outsole 43 having a tread or ground engaging surface 53 consisting of anterior outsole element 44 that includes lines of flexion 54, and a posterior outsole element 46 that extends substantially within the midfoot area 67 and rearfoot area 68. Alternately, posterior outsole element 46 can be made in two portions, that is, a posterior outsole element 46 positioned adjacent the posterior side 34 in the rearfoot area 68, and a stabilizer 63 or middle outsole element 45 having a generally triangular shape positioned substantially in the midfoot area 67. For the sake of brevity, both options have been shown simultaneously in FIG. 3. It can be readily understood that stabilizer 63 or middle outsole element 45 can be made in various configurations, and various different stiffness in compression options can be made in order to optimize desired performance characteristics such as cushioning and stability for an individual wearer, or a target population of wearers. In this regard, a stabilizer 63 or middle outsole element 45 can include a foam material, gas filled bladders, viscous fluids, gels, textiles, thermoplastic materials, and the like.

[0629] FIG. 4 is a longitudinal cross-sectional medial side view of the article of footwear 22 shown in FIG. 1, with parts broken away. Shown in FIG. 4 is a two part outsole 43 consisting of anterior outsole element 44, and posterior outsole element 46, each having a backing 30. Also shown are the upper 23, including a tip 25, vamp 52, heel counter 24, fasteners 29, and insole 31. The insole 31 can be made of a foamed or blown neoprene rubber material including a textile cover and having a thickness of approximately 3.75 mm, or a SORBOTHANE®, or PORON® polyurethane foam material including a textile cover. The insole 31 can include a light cure material for providing a custom fit in accordance with U.S. Pat. No. 5,632,057 granted to the present inventor, hereby incorporated by reference herein The superior spring element 51 underlies the insole 31 and can be configured to approximate the shape of the insole 31 and last bottom about which the upper 23 can be affixed during the manufacturing process, or alternately, to a soft data storage and retrieval computer software three dimensional model relating to the configuration and pattern of the upper 23 of the article of footwear.

[0630] The spring element 51 can consist of a plurality of portions, and preferably three portions, an anterior spring element 48, a posterior spring element 49, and an inferior spring element 50 which can be affixed together in functional relation, e.g., with the use of at least one mechanical fastener 29, and the like. The anterior spring element 48 can underlay a substantial portion of the forefoot area 58 and is preferably affixed to the posterior spring element 49 in the forefoot area 58 or midfoot area 67 posterior of a position in the range between approximately 60-70 percent of the length of the upper 23 of the article of footwear 22 as measured from the posterior side 34, that is, a position posterior of the metatarsal-phalangeal joints of a wearer's foot when the article of footwear 22 is donned. The metatarsal-phalangeal joints are normally located near approximately 70 percent of foot length on the medial side 35 of the foot, and nearer to approximately 60 percent of foot length on the lateral side 36 of the foot. Accordingly the anterior spring element 48 can underlay the metatarsal-phalangeal joints of the foot and energy can temporarily be stored and later released to generate propulsive force when the anterior spring element 48 undergoes bending during the stance and propulsive phases of the running cycle. The anterior spring element 48 can be selectively and removably attached and renewed in the event of damage or failure. Further, a wearer can select from anterior spring elements 48 having different configurations and stiffness, and therefore customize the desired stiffness of the anterior spring element 48 in an article of footwear 22. For example, different individuals having different body weight, running styles, or characteristic running speeds could desire anterior spring elements 48 having different stiffness.

[0631] Likewise, the superior spring element 47 or posterior spring element 46 can be selectively and removably affixed to the inferior spring element 50 in the rearfoot area 68 or midfoot area 67 of the article of footwear 22. Accordingly the superior spring element 47 or posterior spring element 49 can underlay a substantial portion of the wearer's rearfoot and perhaps a portion of the wearer's midfoot and energy can be stored during the braking and early stance phases of the running cycle and released during the later portion of the stance and propulsive phases of the running cycle to provide propulsive force. The anteriormost portion of wearer's rearfoot on the lateral side of the foot is consistent with the junction between the calcaneus and cuboid bones of the foot which is generally in the range between 25-35 percent of a given foot length and that of a corresponding size upper 23 of an article of footwear 22. The superior spring element 47 or posterior spring element 49, and inferior spring element 50 can be selectively and removably attached and renewed in the event of failure. Further, a wearer can select from superior spring elements 47 or posterior spring elements 49, and inferior spring elements 50 having different configurations and stiffness, and therefore customize the desired stiffness of these spring elements in an article of footwear 22. For example, different individuals having different weight, running styles, or characteristic running speeds could desire to select superior spring elements 47 or posterior spring elements 49, and inferior spring elements 50 having different stiffness.

[0632] Accordingly, the spring element 51 of a preferred article of footwear can consist of three portions, an anterior spring element 48 which is positioned anterior of at least approximately 70 percent of the length of the upper 23 of the article of footwear 22 as measured from the posterior side 34, a posterior spring element 49 which extends anteriorly from proximate the posterior side 34 of the upper 23 of the article of footwear 22 and is affixed in functional relation to the anterior spring element 48, and an inferior spring element 50 which is affixed in functional relation to the posterior spring element 49. The inferior spring element 50 projects rearwards and downwards and can extend beneath a substantial portion of the rearfoot area 68 of the article of footwear 22. Alternately, the spring element 51 can be formed in two portions or a single part.

[0633] In the embodiment shown in FIG. 4, the elevation of the wearer's foot in the rearfoot area 68 measured under the weight bearing center of a wearer's heel 57 is approximately 26 mm and the elevation of the wearer's foot in the forefoot area 58 measured under the ball of the foot proximate the metatarsal-phalangeal joints is approximately 16 mm in a size 9 men's article of footwear. The difference in elevation between the forefoot area 58 measured under the ball of the foot and the rearfoot area 68 measured under the weight bearing center of a wearer's heel 57 in a men's size 9 article of footwear is commonly in the range between 10-12 mm, and is approximately 10 mm in the embodiment shown in FIG. 4.

[0634] For some footwear applications, such as competition in track and field or road racing, the maximum amount of deflection that might be desired by some individuals between the superior spring element 47 or posterior spring element 49 and the inferior spring element 50 could be in the range between 8-15 mm. As shown in FIG. 4, the maximum amount of deflection possible as between posterior spring element 49 and inferior spring element 50 is approximately 10 mm. However, greater amounts of deflection in the range between 15-50 mm can be desired for use by some individuals in various footwear applications, as shown and discussed herein with respect to other embodiments of the present invention. Nevertheless, it can be advantageous from the standpoint of injury prevention that the elevation of the rearfoot area 68 minus the maximum amount of deflection permitted between the superior spring element 47 or posterior spring element 49 and the inferior spring element 50 be equal to or greater than the elevation of the forefoot area 58. It can also be advantageous as concerns the longevity of the working Rife of the spring element 51 that the amount of deflection permitted be equal to or less than approximately 75 percent the maximum distance between the proximate opposing sides of the spring element 51, that is, as between the inferior surface of the superior spring element 47 or posterior spring element 49 and the superior surface of the inferior spring element 50.

[0635] The amount of deflection or compression provided under the wearer's foot in the forefoot area 58 by the embodiment shown in FIG. 4 is commonly approximately in the range between 4-6 mm, and such can be provided by an insole 31 having a thickness of 3.75 mm in combination with an anterior outsole element 44 having a total thickness of 6.5 mm including a backing 30 having a thickness of approximately 1.5 mm and a tread or ground engaging portion 53 having a thickness of approximately 5 mm, and in particular, when the ground engaging portion 53 is made of a relatively soft and resilient material having good traction, and shock and vibration dampening characteristics. For example, a foamed natural or synthetic rubber or other elastomeric material can be suitable for use. If hypothetically, an outsole material having advantageous traction, and shock and vibration dampening characteristics only lasts 200 miles during use, that is, as opposed to perhaps 300 miles associated with a harder and longer wearing outsole material, this does not pose a practical problem, as the outsole 43 portions can be easily renewed in the present invention, whereas a conventional article of footwear would normally be discarded. Accordingly, it is possible to obtain better traction, and shock and vibration dampening characteristics in the present invention, as the durability of the outsole 43 portions is not such an important criteria

[0636] FIG. 5 is a longitudinal cross-sectional lateral side view of the article of footwear 22 shown in FIG. 1, with parts broken away. Shown in dashed lines is the medial aspect of the inferior spring element 50. It can be advantageous that the flexural axis 59 be deviated from the transverse axis 91 in the range between 10-50 degrees in an article of footwear intended for use in walking or running. As shown in FIGS. 4 and 5, the flexural axis 59 is deviated at about 35 degrees from the transverse axis 91 of the article of footwear 22.

[0637] It can be readily understood that posterior of the flexural axis 59 the length of the superior lever arm 60 and inferior lever arm 61 formed along the medial side 35 of the superior spring element 47 or posterior spring element 49 and the inferior spring element 50 are shorter than the length of the corresponding superior lever arm 60.1 and inferior lever arm 61.1 formed along the lateral side 36 of the superior spring element 47 or posterior spring element 49 and the inferior spring element 50. Accordingly, when the inferior spring element 50 is affixed in functional relation to the superior spring element 47 or posterior spring element 49 and is subject to compressive loading, the inferior spring element 50 exhibits less stiffness in compression at the lateral and posterior corner, and increasing stiffness in compression both anteriorly and laterally. Again, it can be advantageous for enhancing rearfoot stability during walking or running that the spring element 51 including inferior spring element 50 exhibit approximately two to three times the stiffness in compression on the medial side 35 relative to the stiffness exhibited on the lateral side 36. Further, as shown in FIGS. 4 and 5, the inferior aspect of the spring element 51 has a concave configuration in the midfoot area 67, that is, between the inferior most portion of the anterior spring element 48 in the forefoot area 58 and the inferior most portion of the inferior spring element 50 in the rearfoot area 68. It can be readily understood that the configuration of this concavity 76 and the flexural modulus of the spring element 51, as well as the stiffness of the anterior outsole element 44, middle outsole element 45, posterior outsole element 46, anterior spacer 55, and posterior spacer 42 can be engineered to provide optimal cushioning characteristics such as deflection with respect to the midfoot area 67 and rearfoot area 68 for an individual wearer, or for a target population having similar needs and requirements.

[0638] FIG. 6 is a top view of a spring element 51 in the article of footwear 22 similar to that shown in FIG. 2, but having a relatively more curved shape corresponding to a relatively more curve lasted upper 23 shown in dashed lines. Shown is a spring element 51 consisting of a single full length superior spring element 47.

[0639] FIG. 7 is a top view of a two part spring element 51 consisting of anterior spring element 48 and posterior spring element 49 in the article of footwear 22 shown in FIG. 2, with the upper 23 shown in dashed lines.

[0640] FIG. 8 is a top view of a two part spring element 51 consisting of anterior spring element 48 and posterior spring element 49 in an article of footwear 22 generally similar to that shown in FIG. 2, but having a relatively more curved shape corresponding to a relatively more curve lasted upper 23 which is shown in dashed lines. The anterior spring element 48 and posterior spring element 49 can be affixed with three fasteners 29 in triangulation. The posterior spring element 48 can include a projection 70 proximate the longitudinal axis 69 of the article of footwear 22. The configuration of this projection 70 can at least partially determine the torsional rigidity of the assembled spring element 51 consisting of anterior spring element 48 and posterior spring element 49, thus the degree to which the forefoot area 58 can be rotated inwards or outwards about the longitudinal axis 69. Further, the number, dimension, and location of the fasteners 29 used to affix the anterior spring element 48 and posterior spring element 49 can affect both the flexural modulus of the superior spring element 47 along the length of the longitudinal axis 69, but also rotationally about the longitudinal axis 69, that is, the torsional modulus of the superior spring element 47. A portion of the anterior spring element 48 is shown broken away in order to reveal the optional inclusion of an anterior spacer 55 between the anterior spring element 48 and the posterior spring element 49.

[0641] As shown in FIG. 8, an anterior spacer 55 which can possibly consist of a cushioning medium having desired spring and dampening characteristics can be inserted in the area between the anterior spring element 48 and posterior spring element 49, that is, within an area of possible overlap as between the two components. The configuration and compressive, flexural, and torsional stiffness of an anterior spacer 55 can be used to modify the overall configuration and performance of a spring element 51 and article of footwear 22. In this regard, an anterior spacer 55 can have uniform height, or alternately an anterior spacer 55 can have varied height. Further, an anterior spacer 55 can exhibit uniform compressive, flexural and torsional stiffness throughout, or alternately an anterior spacer 55 can exhibit different compressive, flexural, and torsional stiffness in different locations. These varied characteristics of an anterior spacer 55 can be used to enhance the cushioning, stability and overall performance of an article of footwear 22 for a unique individual wearer, or for a target population of wearers. For example, an anterior spacer 55 having an inclined or wedge shape can be used to decrease the rate and magnitude of pronation, supination, and inward or outward rotation of portions of a wearer's foot during portions of the walking or running gait cycle, and can also possibly correct for anatomical conditions such as varus or valgus. The relevant methods and techniques for making corrections of this kind are relatively well known to qualified medical doctors, podiatrists, and physical therapists. See also U.S. Pat. Nos. 4,399,620, 4,578,882, 4,620,376, 4,642,911, 4,949,476, and 5,921,004, all of these patents hereby being incorporated by reference herein. Normally, an anterior spacer 55 having an inclined wedge shape that increases in height from the lateral to the medial side, or one which exhibits greater stiffness in compression on the medial side can be used to compensate for a forefoot varus condition, whereas an anterior spacer 55 having an inclined wedge shape that increases in height from the medial to the lateral side, or one which exhibits greater stiffness in compression on the lateral side can be used to compensate for a forefoot valgus condition. An individual with a profound anatomical condition such as varus or valgus, or having a history of injury would be prudent to consult with a trained medical doctor when contemplating modification to their articles of footwear. Further, an anterior spacer 55 can also have a wedge or complex curved shape along the longitudinal axis 69, that is, in the posterior to anterior orientation, and various configurations of an anterior spacer 55 can be provided which can be used to modify the amount of toe spring 62 and the overall conformance of a spring element 51 and article of footwear 22, as desired.

[0642] FIG. 9 is a bottom view of the article of footwear 22 shown in FIG. 3, with the anterior outsole element 44 and posterior outsole element 46 removed to reveal the anterior spring element 48, posterior spring element 49, and inferior spring element 50. The flexural axis 59 of inferior spring element 50 is deviated approximately 35 degrees from the transverse axis 91. This configuration can be advantageous for use by distance runners who otherwise tend to pronate significantly during the braking and stance phases of the running cycle. Further, a portion of the inferior spring element 50 is shown broken away to reveal the optional use of a posterior spacer 42 which can serve a role in functional relation to the inferior spring element 50 and the superior spring element 47 or posterior spring element 49 analogous to that of the anterior spacer 55 which can be used as between the anterior spring element 48 and posterior spring element 49. Further, a posterior spacer 42 can also have a wedge or complex curved shape along the longitudinal axis 69, that is, in the posterior to anterior orientation, and various configurations of a posterior spacer 42 can be provided which can be used to modify the overall conformance of a spring element 51 and article of footwear 22, as desired.

[0643] It can be readily understood that in this specification and the associated drawing figures, the orientation and location of the longitudinal axis 69 is determined by longitudinally bisecting the rearfoot area 68 of the article of footwear 22, and likewise, any related components that are present in the rearfoot area 68 such as the inferior spring element 50, and also the posterior portion of the superior spring element 47 or posterior spring element 49. It is recognized that a longitudinal axis 69 drawn in this manner will not bisect the forefoot area 58 of an article of footwear 22 having a substantially curve lasted configuration. The orientation of the transverse axis 91 can be determined by drawing a line perpendicular to the longitudinal axis 69 as defined above, that is, the transverse axis 91 intersects the longitudinal axis 69 at a 90 degree angle. Accordingly, when an article of footwear 22 or component such as an inferior spring element 50 is recited as including or having a longitudinal axis 69 or transverse axis 91, it can be readily understood that this refers to the aforementioned defined coordinate system for describing, e.g., the orientation, relationship, or various specific features of the sub-components which are part of an article of footwear made according to the present invention.

[0644] FIG. 10 is a bottom view of an alternate article of footwear 22 with the anterior outsole element 44 and posterior outsole element 46 removed to reveal anterior spring element 48, posterior spring element 49 and an alternate configuration of inferior spring element 50. The flexural axis 59 of inferior spring element 50 is deviated approximately 30 degrees from the transverse axis 91. The anterior spring element 48, posterior spring element 49, and inferior spring element 50 are shown affixed together in an overlapping relationship in FIGS. 9 and 10. However, it can be readily understood that various components of a spring element 51 can be affixed in function relation with the use of adhesives, mating male and female parts such as tongue and groove, or other configurations and devices known in the prior art.

[0645] The possible use of notches 71 or openings 72 in order to diminish the stiffness in bending or flexural modulus exhibited by a portion of spring element 51, and two substantially transverse lines of flexion 54 is also shown in FIG. 10. Shown with a dashed line 90 in FIG. 10, and also in medial side view in FIG. 14, is the possible inclusion of a rocker 87 configuration in the forefoot area 58 of the sole 32 an article of footwear 22. It can be advantageous for the point of greatest elevation of the rocker 87 to be located approximately in the range between 1-4 cm posterior of the metatarsal-phalangeal joints. The location of the first metatarsal-phalangeal joint 88 on the medial side 35 of an average wearer's foot is normally at slightly less than seventy percent of foot length, and the location of the fifth metatarsal-phalangeal joint 89 on the lateral side 36 is normally somewhat greater than sixty percent of foot length as measured from the posterior side 34 of the wearer's foot. Accordingly, a rocker 87 can be positioned in the range between 1-4 cm behind a generally transverse and slightly diagonal line that can be drawn as between these two approximate positions for any given size article of footwear.

[0646] FIG. 11 is a longitudinal cross-sectional medial side view of an alternate article of footwear 22 generally similar to that shown in FIG. 1, with parts broken away, but having a forefoot area 58 without substantial toe spring 62. This particular article of footwear 22 can be suitable for use in activities such as tennis, volleyball, or basketball.

[0647] FIG. 12 is a longitudinal cross-sectional medial side view of an alternate article of footwear 22 generally similar to that shown in FIG. 11, with parts broken away, having a forefoot area 58 without substantial toe spring 62, but including an anterior outsole element 44, foam midsole 26, and upper 23 which are affixed together with the use of adhesives.

[0648] FIG. 13 is a longitudinal cross-sectional medial side view of an alternate article of footwear 22 generally similar to that shown in FIG. 12, with parts broken away, having a forefoot area 58 without substantial toe spring 62, but including a detachable anterior outsole element 44 and foam midsole 26.

[0649] FIG. 14 is a longitudinal cross-sectional medial side view of an alternate article of footwear 22 similar to that shown in FIG. 4, further including a spring guard 40. The spring guard 40 can be made of a relatively soft resilient material such as a foam material, or a natural or synthetic rubber. The spring guard 40 can prevent foreign matter from becoming lodged in the area proximate the junction of the superior spring element 47 or posterior spring element 49 and the inferior spring element 50, thus can prevent damage to spring element 51. The spring guard 40 can be affixed to the superior spring element 47 or posterior spring element 49, or to the inferior spring element 50, or to both portions of the spring element 51. Alternately, the spring guard 40 can form a portion and extension of posterior spacer 42, as shown in FIG. 18. Further, the spring guard 40 can also serve as a vibration decay time modifier 41, as shown in FIG. 20. Also shown in FIG. 14 is the approximate position of the first metatarsal-phalangeal joint 88 on the medial side 35, and a sole 32 or outsole 43 including a rocker 87 configuration in the forefoot area 58. As shown, the rocker 87 configuration can be formed and substantially consist of a portion of the sole 32 or outsole 43, or alternately, the rocker 87 configuration can be formed at least in part by an inferiorly protruding portion of the spring element 51, and in particular, the anterior spring element 48.

[0650] FIG. 15 is a longitudinal cross-sectional medial side view of an alternate article of footwear 22 generally similar to that shown in FIG. 4, with parts broken away, having a upper 23 including a sleeve 39 for accommodating the superior spring element 47. The sleeve 39 can be formed in a portion of the upper 23 inferior to the insole 31, and can possibly consist of a portion of the t-sock 56. The spring element 51 can include an inferior spring element 50, and a superior spring element 47 that can include an anterior spring element 48 and a posterior spring element 49. The superior spring element 47 can be positioned within sleeve 39, thus at least partially retaining the superior spring element 47 in functional relation to the upper 23 of the article of footwear 22.

[0651] Further, in contrast with the configuration of inferior spring element 50 shown in FIG. 16, an alternate inferior spring element 50.1 is shown in FIG. 15. The alternate inferior spring element 50.1 descends from proximate the superior spring element 47 or posterior spring element 49 and attains maximum separation therefrom. The inferior spring element 50.1 can then possibly extend posteriorly in a parallel relationship with respect to the overlaying superior spring element 47. However, the inferior spring element 50.1 then curves upwards as the inferior spring element 50.1 extends towards the posterior side 34 of the article of footwear 22. It can sometimes be advantageous that the inferior spring element 50.1 be tapered in the range between approximately 1-15 degrees, or otherwise be curved upwards, as it extends towards the posterior side 34 and lateral side 36 corner of the sole 32 of the article of footwear 22.

[0652] FIG. 16 is a longitudinal cross-sectional medial side view of an alternate article of footwear 22 generally similar to that shown in FIG. 4, with parts broken away. However, this alternate embodiment does not include an additional covering such as a coating, textile, or outsole 43 on the inferior side of the upper 23, as shown in FIG. 4. Accordingly, the inferior side of the upper 23 is in direct contact with the superior side of the backing 30 of the outsole 43, that is, anterior outsole element 44 and posterior outsole element 46 when the article of footwear 22 is assembled. Further, in an alternate embodiment of the present invention, the backing 30 of an outsole 43 can be made of a material having sufficient flexural modulus and resilience as to simultaneously serve as a spring element of the article of footwear, as shown in FIG. 16. Accordingly, the anterior spring element can consist of two portions, anterior spring element 48, and anterior spring element 48.1, which also serves as the backing 30 of anterior outsole element 44.

[0653] In the article of footwear shown in FIG. 16, when a line is drawn parallel to the ground support surface and tangent to the inferior surface of the superior spring element 47 in the forefoot area 58, the approximate slope of the superior spring element 47 as it extends posteriorly is approximately five degrees. When affixed in functional relation to the superior spring element 47 or posterior spring element 49, the inferior spring element 50 projects downwards and rearwards therefrom before attaining the desired amount of separation between the components which at least partially determines the maximum amount of deflection that the resulting spring element 51 can provide. As shown in FIG. 16 and several other drawing figures, once the inferior spring element 50 descends and attains the desired amount of separation, the inferior spring element 50 extends posteriorly in a substantially parallel relationship with respect to the corresponding overlaying portion of the superior spring element 47 or posterior spring element 49. Accordingly, after descending from proximate the superior spring element 47 or posterior spring element 49 and establishing the desired amount of separation, the inferior spring element 50 does not curve upwards as it extends towards the posterior side 34 of the article of footwear 22. Instead, it is known in prior art articles of footwear, and can also be advantageous in the present invention for a portion of the outsole 43 near the posterior side 34, and in particular, proximate the posterior side 34 and lateral side 36 corner, to be tapered in the range between 1-15 degrees, or otherwise curved upwards. However, the overall configuration of the article of footwear 22 including the amount of toe spring 62 and the aforementioned slope of the superior spring element 47 can influence or determine the amount of slope or curvature that is advantageous to incorporate in this portion of the outsole 43.

[0654] FIG. 17 is a longitudinal cross-sectional medial side view of an alternate article of footwear 22 generally similar to that shown in FIG. 4, having a upper 23 affixed to superior spring element 47, with parts broken away. The upper 23 is affixed to the top or superior surface of superior spring element 47, thus the superior spring element 47 can be exposed on its bottom or inferior surface. Accordingly, the superior surface of the outsole 43 portions including backing 30 can be placed in direct contact with the superior spring element 47 when they are affixed into position.

[0655] FIG. 18 is a longitudinal cross-sectional medial side view of an alternate article of footwear 22 similar to that shown in FIG. 17, further including a posterior spacer 42. As shown in FIG. 18, a posterior spacer 42 can include a spring guard 40. As shown in FIG. 20, a spring guard 40 can further include a vibration decay time modifier 41. The posterior spacer 42 can serve to at least partially isolate the superior spring element 47, upper 23 and wearer from the transmission of shock and vibration which could be imparted by the inferior spring element 50 and posterior outsole element 46 caused by an impact event.

[0656] It can be readily understood that a posterior spacer 42 can serve a purpose analogous to that of anterior spacer 55, and vice-versa. Accordingly, a posterior spacer 42 can consist of a cushioning medium having desired spring and dampening characteristics. The posterior spacer 42 can be inserted between the inferior spring element 50 and posterior spring element 49, that is, within an area of possible overlap as between the two components. The configuration and stiffness of a posterior spacer 42 can be used to modify the overall configuration and performance of a spring element 51 and article of footwear 22. In this regard, a posterior spacer 42 can have uniform height, or alternately a posterior spacer 42 can have varied height. Further, a posterior spacer 42 can exhibit uniform compressive, flexural, or torsional stiffness throughout, or alternately can exhibit different properties in different locations. These varied characteristics of a posterior spacer 42 can be used to enhance the cushioning and/or stability of an article of footwear 22 for an unique individual wearer, or for a target population of wearers.

[0657] For example, a posterior spacer 42 having an inclined or wedge shape can be used to decrease the rate and magnitude of pronation, supination, inward or outward rotation of portions of a wearer's foot during phases of the walking or running gait cycle, and can also possibly correct for anatomical conditions such as varus or valgus. Again, the relevant methods and techniques for making corrections of this kind are relatively well known to qualified medical doctors, podiatrists, and physical therapists. Normally, a posterior spacer 42 having an inclined wedge shape that increases in height from the lateral to the medial side, or a posterior spacer 42 which exhibits greater stiffness in compression on the medial side can be used to reduce the magnitude and rate of rearfoot pronation, whereas a posterior spacer 42 having an inclined wedge shape that increases in height from the medial to the lateral side, or a posterior spacer 42 which exhibits greater stiffness in compression on the lateral side can be used to reduce the magnitude and rate of rearfoot supination. An individual having a profound anatomical condition such as varus or valgus, an individual who dramatically pronates or supinates, or an individual who has a history of injury would be prudent to consult with a trained medical doctor when contemplating modification to their articles of footwear.

[0658] It can be readily understood that with the use of an anterior spacer 55 positioned between anterior spring element 48 and posterior spring element 49, and a posterior spacer 42 positioned between the superior spring element 47 or posterior spring element 49 and the inferior spring element 50, that the configuration and functional relationship as between the forefoot area 58, midfoot area 67, and rearfoot area 68 of an article of footwear 22 can be adjusted and customized as desired by an individual wearer. Further, the use of an anterior spacer 55 and/or posterior spacer 42 having a select configuration can be used to adjust the amount of support provided by a superior spring element 47 or posterior spring element 49 which can possibly further include contours for mating with the complex curved shapes of a wearer's foot. For example, it is possible to customize the amount of support that is provided to the medial longitudinal, lateral longitudinal and transverse arches, and to the sides of a wearer's foot.

[0659] FIG. 19 is a longitudinal cross-sectional medial side view of an alternate article of footwear 22 having a posterior spacer 22 including a spring guard 40, and also a vibration decay time modifier 41 having a stem 64 and a head 65. The vibration decay time modifier 41 can be affixed in function relation to a portion of spring element 51, and in particular, a portion of an inferior spring element 50. The head 65 of the vibration decay time modifier 41 can be dimensioned and configured for vibration substantially free of contact with a spring element S1 in directions which substantially encompass a 360 degree arc and normal to the longitudinal axis of the stem 64, that is, when the vibration decay time modifier 41 is initially excited by shock and vibration. When the superior spring element 47 or posterior spring element 49 and inferior spring element 50 are subjected to compressive loading a vibration decay time modifier 41 can also serve as a stop and prevent any possible impact between these elements. The inclusion of a posterior spacer 42 and/or a vibration decay time modifier 41 can partially attenuate shock and vibration associated with impact events associated with movements such as walking or running, and can reduce the vibration decay time following an impact event. This can serve to enhance comfort, proprioception, reduce local trauma, and possibly solicit greater application of force and improved athletic performance.

[0660] Generally, the efficiency of a vibration decay time modifier will be enhanced the closer it is positioned in functional relation to a negative nodal point. When properly configured and placed proximate the negative nodal point of an object or implement, relatively little mass is required in order to substantially prevent, or alternately, to attenuate resonant vibration within fractions of a second. A negative nodal point is a point at which a substantial portion of the vibration energy in an excited object or implement will pass when it is excited by energy associated with an impact or other vibration producing event. Discussion of modes of vibration and negative nodal points can be found in Arthur H. Benade, Fundamentals of Musical Acoustics, 2nd edition, New York: Dover Publications, 1990, Harry F. Olson, Music, Physics and Engineering, 2nd edition, New York: Dover Publications, 1967, and U.S. Pat. No. 3,941,380 granted to Francois Rene Lacoste on Mar. 2, 1976, this patent hereby being incorporated by reference herein. A technology taught by Steven C. Sims in U.S. Pat. No. 5,362,046, granted Nov. 4, 1994, this patent hereby being incorporated by reference herein, has been commercialized by Wilson Sporting Goods, Inc. into the SLEDGEHAMMER® INTUNE® tennis rackets, and by Hillerich and Bradsby Company, Inc. in the LOUISVILLE SLUGGER® SIMS STINGSTOP® aluminum baseball and softball bats, as well as the POWERBUILT® SIMS SHOCK RELIEF® golf club line, and LIMBSAVER® product for archery. These products substantially eliminate the vibration and stinging associated with impact events experienced by a wielder's hands. Certain aspects of the aforementioned teachings can be applied in the present invention in order to accomplish a similar results with regards to an article of footwear 22 and the lower extremities of a wearer.

[0661] The source of shock and vibration can derive from a relatively controlled and harmonic movement, such as when a wearer repeatedly impacts the pavement while running in an article of footwear 22. Further, the source of shock and vibration can be random in nature, as when a wearer rides a wheeled vehicle such as a bicycle or motorcycle over rough terrain. Alternately, the source of shock and vibration can be constant and mechanically driven as when a wearer rides a bicycle, or a motor vehicle such as a motorcycle or snowmobile. A shock wave, that is, a shock pulse or discontinuity can travel at the speed of sound in a given medium. In the human body, the speed of sound in bone is approximately 3,200 meters/second, and in soft tissue approximately 1,600 meters I second. A shock wave traveling in a relatively dense fluid medium such as water has approximately five times the power that it does in a less dense fluid medium such as air. It is important to recognize that the human body is largely comprised of water and like fluid medium.

[0662] When a metal bell is struck, the bell will resonate and continue to ring for an extended time while the vibration energy is gradually dampened out. When a small bell is rung, one can place one's hand upon it and silence it. In that case, the primary dampening means for attenuating the resulting shock and vibration is the anatomy of the human subject. The same thing can happen when an impact event takes place as between an individual's foot and the materials which are used in an athletic shoe, and a running surface. When an individual runs on an asphalt surface in running shoes, the sound of the impact event that one hears is the audible portion of the shock wave that has been generated as result of the impact.

[0663] Many individuals know from experience that a vibrating implement or object can numb the hands. This is even more true when the source of the vibration is continuous and driven as when power equipment is being used. Associated with that numbness can be pain, reduced sensation and proprioception, and reduced muscular effort and performance as the body responds to protect itself from a perceived source of trauma and injury. Chronic exposure to high levels of vibration can result in a medical condition known as white finger disease. Generally, the lower extremities of most individuals are not subject to high levels of driven vibration. However, bicycle riders wearing relatively rigid articles of footwear can experience constant driven vibration, thus their feet can become numb or “go to sleep” over time. Motorcycle riders can also experience the same phenomenon.

[0664] The preferred article of footwear includes spring and dampening means for at least partially attenuating shock and vibration, that is, the initial shock pulse, pressure wave, or discontinuity and associated peak g's that are imparted to a wearer due to an impact event. At a cellular or molecular level, such vibration energy is believed to disturb normal functions such as blood flow in tendon tissue. Given appropriate engineering with respect to the characteristic or desired spring stiffness, mass, deflection, frequency, dampening, and percent transmissibility, an article of footwear of the present invention can partially attenuate shock and vibration. Viscous, friction, and mechanical dampening means can be used to attain this end. It is known that the mean power frequency associated with the rearfoot impact event in running generally corresponds to 20 Herz, and that of the forefoot to 5 Herz. The design and configuration, as well as the spring and dampening characteristics of a spring element 51, posterior spacer 42, and vibration decay time modifier 41 can be engineered so as to target these frequencies and provide a specific characteristic tuned mechanical response.

[0665] An anterior spacer 55, posterior spacer 42, and vibration decay time modifier 41 can be made of a cushioning medium such as a natural or synthetic rubber material, or a resilient elastomer such as polyurethane. In this regard, thermoset or thermoplastic materials can be used. Thermoplastic materials can be less expensive to produce as they can be readily injection molded. In contrast, thermoset materials are often compression molded using a relatively time and energy consuming vulcanization process. However, some thermoset materials can possess superior dampening properties and durability. Dampening materials which can be cured with the use of ultrasonic energy, microwave, visible or ultraviolet light, radio frequency, or other portions of the electromagnetic spectrum can be used. Room temperature cure elastomers, such as moisture or evaporation cure, or catalytic cure resilient materials can also be used. A suitable dampening material can be made of a butyl, chloroprene, polynorborene, neoprene, or silicone rubber, and the like. Alternately, a dampening material can be made of an elastomeric material such as polyurethane, or SORBOTHANE®. Suitable hybrid thermoplastic and rubber combinations can also be used, including dynamically vulcanized alloys which can be injection molded such as those produced by Advanced Elastomer Systems, 338 Main Street, Akron, Ohio 44311, e.g., SANTOPRENE®, VYRAM®, GEOLAST®, and TREFSIN®. SANTOPRENE® is known to consist of a combination of butyl rubber and ethylene-propylene. Generally, other materials developed for use in the audio industry for dampening vibration such as EAR ISODAMP®, SINATRA®, EYDEX®, and the like, or combinations thereof, can be used. Fillers such as organic or inorganic microspheres, carbon black or other conventional fillers can be used. Plasticizing agents such as fluids or oils can be used to modify the physical and mechanical properties of the dampening material in a desired manner. The preferred dampening material has transition characteristics suitable for the expected operational temperature of an article of footwear 22, and other physical and mechanical properties well suited to dampen shock and vibration and reduce vibration decay time.

[0666] It can be advantageous that the dampening material used to make a solitary vibration decay time modifier 41 including a stem 64 and a head 65 have a hardness in the range of 10-30 durometer, and preferably approximately 20 durometer on the Shore A scale. A relatively soft dampening material is capable a dampening a wide range of exciting vibration frequencies, and also relatively low vibration frequencies. However, a harder dampening material having greater shear and tear strength can sometimes be advantageous for use when making an anterior spacer 55 or posterior spacer 42 due to the magnitude of the loads which can be placed upon these components during use. A vibration decay time modifier 41 can be affixed to spring element 51 by conventional means such as adhesive, mechanically mating parts, chemical bonding, heat and pressure welding, radio frequency welding, compression molding, injection molding, photocuring, and the like.

[0667] In a conventional article of footwear having a foam midsole and rubber outsole, the materials located between the wearer's foot and the inferior ground engaging surface of the outsole normally become compressed during footstrike and subsequent loading of the sole. During compressive loading the stiffness of these materials increases linearly or geometrically and as result the ability of the sole to dampen shock and vibration rapidly diminishes. Further, the area of the sole which transmits most of the shock and vibration can be relatively small and localized. In this regard, the energy associated with a shock pulse or discontinuity passes tends to pass quickly by the shortest route and through the hardest or stiffest material in which it is in communication. Again, the transmission of shock and vibration is extremely fast in the human body and the materials used in conventional articles of footwear. In a conventional article of footwear, the shock and vibration resulting from impact with the support surface is rapidly transmitted through the outsole, midsole, upper and insole and into a wearer's foot.

[0668] However, in the present invention the shock and vibration generated proximate the inferior ground engaging surface 53 of the outsole 43 must travel anteriorly along the outsole 43 and inferior spring element 50 before being transmitted to the superior spring element 47, upper 23 and wearer, thus for a greater distance relative to a conventional article of footwear. This affords more time and space in which to attenuate and dampen shock and vibration. Further, in the present invention the outsole 43 can be made of a softer material having better shock and vibration dampening characteristics than is normally the case in a conventional article of footwear. In addition, a posterior spacer 42 can serve as a shock and vibration isolator between the inferior spring element 50 and the superior spring element 47, upper 23, and wearer's foot. Moreover, as shown in FIGS. 19 and 20, at least one vibration decay time modifier 41 can be positioned in direct communication with inferior spring element 50 in order to dampen shock and vibration before it can be transmitted to a wearer. Accordingly, the present invention can provide a wearer with enhanced cushioning, shock and vibration isolation, and dampening effects relative to conventional footwear constructions.

[0669] FIG. 20 is a longitudinal cross-sectional medial side view of an alternate article of footwear 22 including a posterior spacer 42 similar to that shown in FIG. 18. As shown in FIG. 20, a posterior spacer 42 can include a spring guard 40 and at least one protrusion which can be configured and engineered to serve as a vibration decay time modifier 41.

[0670] FIG. 21 is a longitudinal cross-sectional medial side view of an alternate article of footwear 22 generally similar to that shown in FIG. 1, but having various components including the upper 23, spring element 51, and outsole 43 affixed together with the use of adhesives in the manner of a conventional article of footwear.

[0671] FIG. 22 is a bottom view of an alternate article of footwear 22 generally similar to that shown in FIG. 3, having a spring element 51 configured for accommodating a detachable bicycle cleat 73. The article of footwear 22 can then serve as bicycling shoe, and possibly also as a functional upper 23 for an in-line skate, as taught in the applicant's co-pending U.S. patent application Ser. No. 09/228,206 entitled “Wheeled Skate With Step-In Binding And Brakes,” hereby incorporated by reference herein.

[0672] Also shown in FIG. 22 is flexural axis 59, and with the use of a dashed line, an alternate position of flexural axis 59.1 with reference to the longitudinal axis 69. It can be readily understood that other more anterior or more posterior positions of a flexural axis 59 with reference to the longitudinal axis 69 are possible. The position of the flexural axis 59 can be selected in order to influence or determine the physical and mechanical properties of a spring element 51, and the overall conformance and performance of an article of footwear 22, as desired. Generally, it can be advantageous that the posteriormost portion of the flexural axis on the medial side be located in the range between 1-6 inches from the posterior side of the upper, and in particular, in the range between 2-4 inches from the posterior side of the upper. However, in the footwear embodiment shown in FIG. 22, it can be advantageous both with respect to the stability of the preferred article of footwear 22, but also the weight and cost of the spring element, that the posteriormost position of the flexural axis 59 on the medial side 35 be located approximately in the range between 1-3.5 inches from the posterior side 34 of the upper 23 in a men's size 9 article of footwear 22. The method of grading and scaling various footwear components for other men's or women's sizes is well known in the footwear industry, thus the preferred range as concerns the position of the flexural axis 59 on the medial side 32 can be determined from this information for any given size article of footwear 22.

[0673] It can be readily understood that this teaching concerning the angular orientation of the flexural axis 59 with reference to the longitudinal axis 69 can be applied to other embodiments of a preferred article of footwear 22. Possible angular deviation of the flexural axis 59 from the transverse axis 91 in the range between 10-50 degrees was previously discussed. One advantage to using a flexural axis 59 that is deviated from the transverse axis 91 in the range between 10-50 degrees is that it permits the use of an inferior spring element 50 having a relatively homogenous construction and a substantially uniform thickness, and this both serves to reduce manufacturing costs and enhances product reliability. It can be readily understood that various combinations and permutations with respect to the position of the flexural axis 59 with reference to the longitudinal axis 69 and the angular deviation of the flexural axis 59 from the transverse axis 91 can be functional.

[0674] FIG. 23 is a medial side view of an alternate article of footwear 22 generally similar to that shown in FIG. 17, but having the anterior outsole element 44, posterior outsole element 46, and inferior spring element 50 removed, and further including track spike elements 66. This embodiment can facilitate enhanced athletic performance and can be used by track and field athletes in the sprinting and jumping events. Further, the spring element 51 can extend upwards about the area of the heel to form an integral heel counter 24, as shown in FIG. 23. In addition, the spring element 51 can extend upwards about the lateral side 36 of the forefoot area 58 to form a side support 74, as shown with dashed lines in FIG. 23. Various configurations of a side support 74 and/or an integral heel counter 24 can be incorporated in any or all embodiments of a preferred article of footwear 22, as desired. Moreover, the superior spring element 47 used in any or all embodiments of a preferred article of footwear 22 can be configured to mate with or otherwise support the complex curved shapes and structures associated with the anatomy of the human foot.

[0675] FIG. 24 is a cross sectional view of the anterior spacer 55 included in the article of footwear 22 shown in FIG. 8, taken along line 24—24. As shown in FIG. 24, the anterior spacer 55 has a uniform elevation.

[0676] FIG. 25 is a cross sectional view of an alternate anterior spacer 55.1 generally similar to that shown in FIG. 8, but having a wedge shape 28, taken along a line consistent with line 24—24. As shown in FIG. 25, the anterior spacer 55.1 has a wedge shape 28 which slopes upward from the lateral side 36 to the medial side 35.

[0677] FIG. 26 is a cross sectional view of the posterior spacer 42 included in the article of footwear 22 shown in FIG. 9, taken along line 26—26. As shown in FIG. 26, the posterior spacer 42 has a uniform elevation.

[0678] FIG. 27 is a cross sectional view of an alternate posterior spacer generally similar to that shown in FIG. 9, but having a wedge shape, taken along a line consistent with line 26—26. As shown in FIG. 27, the posterior spacer 42.1 has a wedge shape 28 which slopes upward from the lateral side 36 to the medial side 35.

[0679] FIGS. 24-27 have been provided to illustrate a few of the possible configurations of an anterior spacer 55 and posterior spacer 22, and other variations are both possible and anticipated. For example, the configuration and slope of the wedge shapes 28 can be the opposite of that represented, and the anterior spacer 55 and/or posterior spacer 22 can slope upwards from the medial side 35 to the lateral side 36. Further, the anterior spacer 55 and/or posterior spacer 22 can have more complex or compound curved shapes. In addition, it can be readily understood that the amount of elevation and/or degree of slope of the anterior spacer 55 and/or posterior spacer 42 can be varied. The compressive, flexural and torsional stiffness of different anterior spacers 55 and/or posterior spacers 22 can also be varied. Moreover, an anterior spacer 55 and/or posterior spacer 22 can be made to exhibit differential stiffness in different portions.

[0680] Again, an anterior spacer 55 or posterior spacer 42 can also have a wedge or complex curved shape along the longitudinal axis 69, that is, in the posterior to anterior orientation, and various configurations can be provided which can be used to modify the overall conformance of a spring element 51 and article of footwear 22, as desired. Accordingly, many variables can be manipulated and selected to optimize the configuration and performance of an article of footwear for an individual, or for a given target population having similar characteristics and requirements.

[0681] FIG. 28 is a longitudinal cross-sectional medial side view of an alternate article of footwear 22 having a different configuration of a spring element 51, with parts broken away. In this embodiment, the anterior spring element 48 and inferior spring element 50 can be affixed in functional relation with the use of mechanical means such as fasteners 29, and the like, or alternately be formed as a single component identified herein as anterior and inferior spring element 75. The anterior portion of the spring element 51 can pass through a slit in the t-sock 56 or upper 23 and then be affixed with fasteners 29 to outsole 43, thereby firmly securing the upper 23 in functional relation thereto. As shown, the posterior spring element 49 can be affixed to the posterior portion of the spring element 51 with at least one fastener 29, and a posterior spacer 42 can also be inserted therebetween. Alternately, the posterior spacer 42 be formed as a coating or otherwise consist of a portion of the t-sock 56 or upper 23. As shown in FIG. 28, the posterior spring element 49 can be made to further include an integral heel counter 24.

[0682] FIG. 29 is a longitudinal cross-sectional medial side view of an alternate article of footwear 22 including a superior spring element 47, and a selectively removable sole 32. The superior spring element 47 can have the approximate configuration of the bottom net of a corresponding last 80 or other hard template, model, or pattern. Alternately, the superior spring element 47 can be made in accordance with a soft model created and maintained in a data storage and retrieval computer environment. A superior spring element 47 can possibly simultaneously consist and serve as a lasting board 79, and vice-versa. However, not every structure and material composition of a lasting board 79 would be such as to possibly create or serve as a spring element 51. A lasting board 79 can-be made of wood, cellulose, cardboard, or other natural fiber, reconstituted leather, a textile formed by knitting or weaving, a non-woven textile, a textile formed by stitch bonding, metal such as steel, spring steel, aluminum, or titanium, a thermoplastic material such as nylon, polyester, polypropylene, an elastomer such as polyurethane, thermoplastic rubber or other natural or synthetic rubber, or alternately, as preferred and previously discussed in detail, a fiber composite material such as carbon fiber.

[0683] The sole 32 can include separate midsole 26 and outsole 43 components, or can be made as a single component. Various sole 32 components can be made having different physical and mechanical characteristics, and performance capabilities for possible selection and use by a wearer. The sole 32 can be selectively removed and replaced by a wearer in order to customize the article of footwear 22, or to renew a component, as desired. As shown in FIG. 29, the spring element 51 does not include an inferior spring element 50, rather the spring element 51 consists of a superior spring element 47, or an anterior spring element 48 and posterior spring element 49 which are affixed in functional relation.

[0684] FIG. 30 shows a bottom view of an alternate article of footwear 22 having an anterior lasting board 79 positioned in the forefoot area 58. Also shown is a portion of the inferior side 38 of the upper 23 including a plurality openings 72 which can be made to register with corresponding openings 72 in an anterior lasting board 79, thus enabling the use of a plurality of fasteners 29 to affix the upper 23 in functional relation to the anterior lasting board 79, and a sole 32 which can possibly include a midsole 26 and outsole 43, or merely an outsole 43. The article of footwear 22 shown in FIG. 30 also consists of a slip-lasted construction in the forefoot area 58 including a t-sock 56 to which the upper 23 is affixed by stitching or adhesive, or other conventional means. The t-sock 56 can consist of a substantially non-stretchlastic textile material, but preferably consists of a stretchlastic textile material. Alternately, the t-sock 56 can be made of cellulose, paper, cardboard, or other natural fiber, reconstituted leather, a textile formed by knitting or weaving, a non-woven textile, a textile formed by stitch bonding, a thin film or sheet consisting of thermoplastic material such as nylon, polyester, polypropylene, and the like, an elastomer such as polyurethane, thermoplastic rubber or other natural or synthetic rubber. Alternately, the upper 23 can consist of a different type of slip lasted construction, a moccasin construction, a string lasted construction, or another conventional footwear construction known in the art. The article of footwear 22 can include a sole 32 in the midfoot area 67 and rearfoot area 68 which is affixed to the upper 23 in a conventional manner with the use of adhesives. Alternately, the sole 32 can be affixed to a full length lasting board 79, or a posterior lasting board 79 with the use of fasteners 29.

[0685] It can be readily understood that within certain practical limitations, different lasting boards 79 having different configurations possibly including different lengths, foot shapes, and widths can be used with a given upper 23 in order to customize the fit of an article of footwear 22 for a unique individual or target population. For example, a plurality of lasting boards 79 can be developed for use with different target populations consisting of individuals having generally similar anatomical characteristics and foot dimensions. Further, it can also be readily understood that within certain practical limitations, different uppers 23 having different configurations possibly including different lengths, widths, and foot shapes can be used with a given lasting board 79 in order to customize the fit of an article of footwear 22 for a unique individual or target population. For example, a plurality of uppers 23 can be developed for use with different target populations consisting of individuals having generally similar anatomical characteristics and foot dimensions.

[0686] FIG. 31 shows a bottom view of the inferior side 38 of the upper 23 of an article of footwear 22 generally similar to that shown in FIG. 30, but including two alternate openings 72 at a plurality of different positions at which a fastener 29 can be used. In the American sizing system, a change in length by one size corresponds to ⅓ inch, and changes in width as between respective sizes A, B, C, D, and E are associated with increments of ¼ inch. Further, the increments in length and width associated with other sizing systems are also known. Given an upper 23 having two alternate openings 72 that are separated by ¼ inch for possible use at each different position at which a fastener 29 can be used, and in particular, about the forefoot area 58, it is possible for the article of footwear 22 to provide three possible options such as width sizes B, C, and D. For example, if the openings 72 closest to the lateral side 23 and medial side 22 are associated with an article of footwear 22 having a B width, then increasing the width of the upper 23 by moving the adjacent opening 72 on one side or the other to that position will provide a width, and moving the other adjacent opening 72 on the opposite side in like manner will provide a D width. It is generally advantageous to configure an upper 23 having only two alternate openings 72 for possible use at each different position at which a fastener 29 can be used in accordance with the width sizing model shown in FIG. 32.

[0687] FIG. 32 shows an article of footwear 22 which is adjustable along the entire length of the upper 23 including the forefoot area 58, midfoot area 67, and rearfoot area 68 having two alternate openings 72 for possible use at each different position at which a fastener 29 can be used, and the possible use of local reinforcement material 81 in the area about the openings 72. The reinforcement material 81 can be made of tape, textile, plastic, natural or synthetic rubber, natural or synthetic leather, metal, or other robust material which serves to enhance the strength of the upper 23. The reinforcement material 81 can also be tactified, or otherwise possess relatively high static and dynamic coefficients of friction, and can possibly include a self-adhesive material 83. Nevertheless, it can be advantageous that the self-adhesive material 83 have a repeatable or renewable adhesion and release capability. Also shown is the use of a t-sock 56 made of stretchlastic material that has greater than 100 percent elongation which can easily accommodate the possible ½ inch width expansion of the upper 23.

[0688] FIG. 33 shows a bottom view of the inferior side 38 of the upper 23 of an article of footwear generally similar to that shown in FIGS. 30 and 31, but including three alternate openings 72 for possible use at each different position at which a fastener 29 can be used. In the American sizing system, a change in length by one size corresponds to ⅓ inch, and changes in width as between respective sizes A, B, C, D, and E are associated with increments of ¼ inch. Further, the increments in length and width associated with other sizing systems are also known Given an upper 23 having three alternate openings 72 that are separated by ¼ inch for possible use at each fastener 29 position, and in particular, about the forefoot area 58, it is possible for the article of footwear 22 to provide five possible width size options such as width sizes A, B, C, D, and E. For example, if the openings 72 closest to the lateral side 23 and medial side 22 are associated with an article of footwear 22 having a size A width, then increasing the width of the upper 23 by moving the next adjacent opening 72 on one side or the other to that position will provide a B width, and moving the other adjacent opening 72 on the opposite side will provide a C width, and so on, thus possibly also providing size D and E widths, as desired. It can be advantageous to configure an upper 23 having three alternate openings 72 for possible use at each different position at which a fastener 29 can be used in accordance with the width sizing model shown in FIG. 34.

[0689] FIG. 34 shows an upper 23 having three alternate openings 72 for possible use at each different position at which a fastener 29 can be used, and also the possible use of reinforcement material 81 in the area about and between the openings 72. This reinforcement material 81 can be made of tape, textile, plastic, natural or synthetic rubber, natural or synthetic leather, metal, or other robust material that will serve to enhance the strength of the upper 23. The reinforcement material 81 can also be tactified, or otherwise possess a relatively high static and dynamic coefficient of friction, and can possibly include a self-adhesive material 83. Nevertheless, it can be advantageous that the self-adhesive material 83 have a repeatable or renewable adhesion and release capability. Also shown is the use of a t-sock 56 made of stretchlastic material that has greater than 100 percent elongation which can easily accommodate the possible 1 inch width expansion of the upper 23.

[0690] FIG. 35 shows a lasting board 79 for the forefoot area 58 including a plurality of openings 72, or alternately, a plurality of indications with respect to making a plurality of openings 72 for use in the present invention. These openings 72 can provide alternate positions for use in affixing portions of the upper 23 in functional relation to the lasting board 79 with the use of fasteners 29. Also shown is the use of a code for indicating each different position where a fastener 29 can be used, and also the three alternative openings 72 for possible use at each different position. The same code can also be used with corresponding parts of the upper 23 and sole 32. Accordingly, the information and intelligence created from the raw data which has been collected with respect to an individual wearer or target population can indicate the selection of a specific lasting board 79 and also a specific code indicating the openings 72 to be used in order to provide an individual wearer or target population with an optimal or preferred custom fit. For example, various lasting boards 79 having a particular size length, foot shape configuration, and size width can be given numerical and/or alphabetical identification. Further, the various different positions at which a fastener 29 can be used, and in particular, the alternate openings 72 which are present at each different position can be given an alphabetical and/or numerical identification, as shown in FIG. 35.

[0691] Accordingly, the raw data or feedback provided by an individual when transformed into information and intelligence could possibly indicate the selection a lasting board 79 having American length size 11, last or foot shape number 3 from amongst a possible selection of thirty different last or foot shape configurations, and also indicate selection of the following code with respect to utilization of the various different positions and alternate openings 72: Code 1.1/2.2/3.2/4.2/5.2/6.1/7.2/8.2. In contrast, an different individual could require the same lasting board 79 having American length size 11, last or foot shape number 3, but a different code for optimal utilization of the various different positions and alternate openings 72, e.g., Code 1.2/2.1/3.1/4.2/5.3/6.1/7.2/8.2. Obviously, a different individual could require a lasting board 79 having a different length and also a different last or foot shape, and the data and preferences of different individuals can also indicate or result in the selection of different uppers 23 having different functions, designs, styles, materials, and sizes.

[0692] FIG. 36 shows an alternate lasting board 79 or spring element 51 for use in the forefoot area 58 of an article of footwear 22. The spring element 51 consists of a posterior spring element 49 and an anterior spring element 48 which includes a longitudinal slit 82 that at least partially separates the medial side 35 from the lateral side 36 and permits somewhat independent articulation and flexion of these two portions. It can be advantageous for the position of the longitudinal slit 82 to coincide with the space between an wearer's first and second toes and corresponding metatarsals, or alternately, with the space between an wearer's second and third toes and corresponding metatarsals. This can facilitate independent articulation of the toes and metatarsals of the foot and possibly enhance both comfort and athletic performance. See also U.S. Pat. No. 5,384,973 granted to the present inventor and assigned to Nine, Inc., previously incorporated by reference herein. The physical and mechanical properties of the anterior spring element 48 can be varied as between its anterior side and posterior side, but also as between its medial side 35 and lateral side 36.

[0693] A lasting board 79 or spring element 51 component having a given size length can also sometimes be used with articles of footwear 22 which are in the range between one to three different half sizes longer and shorter. As shown in FIG. 36, at least one alternate set of openings 72 can be included on the posterior spring element 49 for affixing the posterior spring element 49 in functional relation to the anterior spring element 48. Further, an alternate set of openings 72 can be included on the anterior spring element 48 for the same purpose. In the American sizing system, length changes of one full size approximately correspond to increments of ⅓rd of an inch, and the distances associated with other sizing systems are also known. Accordingly, two sets of alternate openings 72 spaced apart by a distance corresponding to a full size length can sometimes render a lasting board 79 or spring element 51 suitable for use with three or four sizes.

[0694] FIG. 37 shows a different alternate lasting board 79 or spring element 51 including an anterior spring element 48 and a posterior spring element 49. The anterior spring element 48 for use in the forefoot area 58 of an article of footwear 22 consists of two separate parts, that is, a medial anterior spring element 78, and lateral anterior spring element 77. This configuration separates the medial side 35 from the lateral side 36 and permits substantial independent articulation and flexion of these two parts. It can be advantageous for the position of the longitudinal opening 72 between the medial anterior spring element 78 and lateral anterior spring element 77 to coincide with the space between an wearer's first and second toes and corresponding metatarsals, or alternately, with the space between an wearer's second and third toes and corresponding metatarsals. This can facilitate independent articulation of the toes and metatarsals of the foot and possibly enhance both comfort and athletic performance. See U.S. Pat. No. 5,384,973 granted to the present inventor and assigned to Nike, Inc., previously incorporated by reference herein. The physical and mechanical properties of the medial anterior spring element 78 and lateral anterior spring element 77 can be varied as between their respective anterior sides and posterior sides, but also as between their respective medial sides 35 and lateral sides 36. Further, the configuration and also the physical and mechanical properties of the medial anterior spring element 78 and lateral anterior spring element 77 can be different from one another. In addition, different medial anterior spring elements 78 and lateral anterior spring elements 77 can be selected for use in an article of footwear 22. Also shown in FIG. 37 is the possible use of a plurality of different alternate openings 72 for affixing the medial anterior spring element 78 and lateral anterior spring element 77 in different relative positions. Given American footwear sizing, if the medial anterior spring element 78 and lateral anterior spring element 77 are configured to provide a size B width when the two parts are in a closed position, that is, the two parts are adjacent to one another, then moving one of the parts ¼ inch will provide a size C width, and moving the other part ¼ inch will provide a D width, and the two parts will then be separated by ½ inch. If the medial anterior spring element 78 and lateral anterior spring element 77 are configured to provide a size A width when the two parts are in a closed position, that is, the two parts are adjacent to one another, then moving one of the parts ¼ inch will provide a size B width, and moving the other part ¼ inch will provide a C width, and so on, such that when providing an E width the two parts will be separated by one inch. The position of any potential openings 72 corresponding to half or whole size increments associated with a given sizing system which are to be made in portions of a lasting board 79, spring element 51, upper 23, or sole 32, can be indicated upon any or all of the components, or alternately, the various openings 72 can be made in stock parts intended for future use. Further, it can be readily understood that the openings 72 and any other adjustments which are made to various components of a customized article of footwear 22 can be unique to an individual wearer.

[0695] FIG. 38 is a transverse and exploded cross-sectional view taken along line 38—38 in FIG. 16 of an alternate article of footwear 22 showing a lasting board 79 or spring element 51 having male mechanical engagement means affixed thereto, and also an upper 23, insole 31, sole 32, and female mechanical engagement means for engaging in functional relation with the male mechanical engagement means. The male and female mechanical engagement means can consist of fasteners 29 have a male part 85 and a female part 86. Alternately, the male part 85 can be affixed to the sole 32, or the fasteners 29 can consist of loose parts. The fasteners 29 shown on the left in FIG. 38 can be visible on the inferior side 38 of the sole 32. Alternately, a fastener 29 can include a male part 85 or female part 86 which is affixed within the sole 32, and the corresponding mating part can be inserted and affixed in functional relation from the superior side within the defined space of the upper 23 of an article of footwear 22, as shown on the right in FIG. 43. Alternately, as shown on the right in FIG. 38, the fasteners 29 can include a resilient material suitable for use on the sole 32 or outsole 43 such that the fasteners 29 are hardly visible and their use does not appreciably degrade the cushioning or traction provided by the sole 32 or outsole 43. Alternately, a fastener 29 including a resilient material or other material can project from the surface of the sole and form a traction member, lug, or cleat, as shown in FIG. 23.

[0696] FIG. 39 is a transverse cross-sectional view ten at a position consistent with line 38—38 in FIG. 16 of an alternate article of footwear 22 showing an insole 31 overlapping the superior side 38, medial side 35, lateral side 36, and a portion of the inferior side 38 of a lasting board 79 or spring element 51. The insole 31 can include a stock fit recess 84 for receiving the lasting board 79 or spring element 51. The insole 31 can be affixed by adhesive or overmolded to the lasting board 79 or spring element 51. Alternately, a portion of the insole 31 can be trapped between the inferior side 38 of the lasting board 79 or spring element 51 and the upper 23 when the article of footwear 32 is assembled, as shown in FIG. 39. This configuration can also serve to protect and cushion the edges of the lasting board 79 or spring element 51.

[0697] FIG. 40 is a cross-sectional view taken at a position consistent with line 38—38 in FIG. 16 of an alternate article of footwear 22 showing a portion of the sole 32 or outsole 43 overlapping the inferior side 38, medial side 35, lateral side 36, and a portion to the superior side 37 of a lasting board 79 or spring element 51. This configuration serves to cover and protect the sides of the spring element 51. The spring element 51 and outsole 43 can be affixed to the upper 23 using a separate lasting board 79 positioned within the upper 23 and secured with fasteners 29. Alternately, a backing 30 can be used and take the position of the spring element 51, and the spring element 51 can be used and take the position of the lasting board 79, that is, the spring element 51 can simultaneously serve as the lasting board 79, as previously discussed.

[0698] FIG. 41 is a transverse cross-sectional view taken at a position consistent with line 38—38 in FIG. 16 of an alternate article of footwear 22 showing a separate lasting board 79 and a spring element 51, and also an upper 23, insole 31, and outsole 43. In this alternate embodiment of an article footwear 22, the outsole 43 can cover, be affixed, bonded, or over-molded to the spring element 51. The spring element 5 l can be completely covered by the outsole 43 on the inferior side 38, or alternately, portions of the spring element 51 can be visible and exposed.

[0699] FIG. 42 is a transverse cross-sectional view taken at a position consistent with line 38—38 in FIG. 16 of an article of footwear 22 showing a sole 32 or outsole 43 that is directly affixed and integral to the upper 23, and also a lasting board 79 or spring element 51, and an insole 31. The upper 23 can be made at least in part of a synthetic textile or leather made of a thermoplastic material, and the sole 32 can be made of the same type of thermoplastic material, or alternately, a different material which can be bonded to the upper 23. For example, a polyurethane material can be used for this purpose. The sole 32 can be affixed or overmolded onto the upper 23 by direct injection method. The direct injection process can be performed upon a substantially finished upper 23 into which a last 80 has been inserted, or upon an unfinished upper 23 which still has a relatively flat configuration and the upper 23 of the article of footwear 22 can then be completed using a three dimensional stitching process.

[0700] FIG. 43 is a transverse cross-sectional view taken along a position consistent with line 38—38 in FIG. 16 of an alternate article of footwear 22 showing a sole 32 directly affixed to an upper 23, an insole 31, and also a lasting board 79 or spring element 51 located within a recess 84. The contours associated with the recess 84 can provide a mechanical interlock between the upper 23, spring element 51, and backing 30 of the sole 32 or outsole 43. As shown in FIG. 43, the lasting board 79 or spring element 51 does not extend to the perimeter of the upper 23 or sole 32, and this can reduce the stiffness exhibited at the perimeter or edge of the sole 32, as discussed in U.S. Pat. No. 5,921,004 granted to the present inventor, and assigned to Nike, Inc., hereby incorporated by reference herein. It can be advantageous in an article of footwear 22 intended for use in running to extend the lasting board 79 or spring element 51 to the perimeter or edge of the sole 32 in those areas which are shown in dark shading in FIG. 24 of U.S. Pat. No. 5,921,004, but not to the perimeter or edge of the sole 32 in those areas which are not shaded. Accordingly, in the transverse cross-sectional view shown in FIG. 43, it can be advantageous to extend the lasting board 79 or spring element 51 to the perimeter or edge of the sole 32 on the medial side 35, but not on the lateral side 36. The sole 32 can be removably affixed to the upper 23 with the use of fasteners 29, and the lie. As shown on the right in FIG. 43, a fastener 29 can include a male part 85 or female part 86 which is affixed within the sole 32, and the corresponding mating part can be inserted and affixed in functional relation from the superior side within the defined space of the upper 23 of an article of footwear 22. Alternately, the sole 32 can be permanently affixed to the upper 23 with the use of adhesives, or overmolded by direct injection process.

[0701] FIG. 44 is a medal side view of an article of footwear 22 comprising a sandal which includes a spring element 51. Again, a spring element 51 can include an anterior spring element 48, a posterior spring element 49, and an inferior spring element 50 affixed together in functional relation. It can be readily understood that a plurality of different designs and configurations are possible with respect to the upper 23 of a preferred sandal. A sandal according to the present invention can be designed for high fashion, or alternately, for hiking and recreational use, as shown in FIG. 44. Further, the various components of a sandal can be affixed together with adhesive, or alternately, can be selectively and removably replaced with the use of mechanical engagement means including but not limited to fasteners 29, and the like.

[0702] The present invention teaches and makes possible not only a novel method of manufacturing articles of footwear, but also, a novel way of doing both retail and Internet business. The configuration and dimensions of a given wearer's foot and any other special needs and requirements or wearer preferences can be recorded by direct observation and measurement in a retail or medical setting, or by a wearer or other individual at their home or other remote site, and this data can be used to generate information and intelligence relating to the manufacture of an appropriate custom article of footwear for the wearer and intended end use. This information and intelligence relating to an individual wearer or target population can include a so-called soft virtual model that is created and maintained in computer software or other data storage and retrieval system for present and future use.

[0703] Conventional measuring or reproduction means including but not limited to rulers, measuring tapes, Brannock devices, two or three dimensional scanners, pressure sensors, infrared thermography, stereolithography, paper, photographs, photocopies, cameras, images, tracings, video, verbal communication, telephone, television, FAX, computers and computer screens, software, data storage and retrieval systems, e-mail, lasts, lasting boards, templates, molds, models, and patterns can be used, as well as other tangible mediums of expression, and the like. Some of the data which might be collected could include, but not be limited to an individual's: foot length, foot width at one or more locations; foot girth at one or more locations; arch characteristics such as high arch, normal arch, or low arch; the presence of a varus or valgus condition; bunions; Morton's toe; two dimensional foot shape; three dimensional foot shape; data collected using F-scan equipment and software made by Tekscan, Inc. of Boston, Mass.; strike index, plantar pressure, and center of pressure data collected using Pedar or Emed equipment made by Novel Electronics, Inc. of St. Paul, Minn.; digital photographs or video images showing superior, inferior, anterior, medial, lateral, and perspective views of an individual's foot; video data collected of an individual while in motion using digital cameras; biomechanical analysis of an individual's motion such as rearfoot motion analysis, and possibly including top, bottom, side, frontal, rear, and perspective view using equipment and software made by manufacturers such as Mikromak GmbH, of Erlangen, Germany, Northern Digital of Waterloo, Ontario, Canada, Motion Analysis of Santa Rosa, Calif., VICON Motion Systems of Lake Forest, Calif., or Peak Performance Technologies, Inc., of Englewood, Colo.; and, the individuals name; mailing and e-mail address; password, phone number; sex; weight; age; training age; walking or running pace; fit preference such as loose, normal, or tight; activity preference; affiliation; sizing system preference such as inches or metric; place of payment such as zip code or city; method of payment such as cash, check, debit card, credit card, and including the relevant account number and expiration date.

[0704] Given this collected raw data, information and intelligence can then be created including an individual record which could include a virtual model of an individual's feet. This information and intelligence can be used to select one or more options with respect to a footwear last, or other footwear configuration including length size, width, and girth measurements. Accordingly, this information and intelligence can be used to identify specific categories and footwear models for consideration. If and when working in a computer environment, the various options can be displayed for consideration and selection. Further, an individual can then click on various categories or models in order to receive additional technical information and also pricing information. In addition, an individual can then click on various segments or components of a virtual model or article of footwear being presented, and so access more specific menus relating to selections which can be made according to their preference with respect to the structure, function, material, color, and design of a given component. Accordingly, an individual can make a final and confirmed selection.

[0705] Given the collected data, the information and intelligence created, and a ready and adequate stock of the various components anticipated for use in making articles of footwear, an individual consumer, or alternately, a worker in a retail, medical, manufacturing, or distribution center which possibly includes an automated system including robotics can gather the required components for assembly. An individual can then purchase the required components and assemble the article of footwear themselves. Alternately, the article of footwear can be manufactured or assembled by a worker in a retail, medical, manufacturing, or distribution center. In any case, a custom article of footwear can be manufactured and assembled within thirty minutes, and in some cases even in less than one minute.

[0706] For example, selections can be made from a ready stock of different uppers 23, lasting boards 79, spring elements 51 and related sub-component parts, insoles 31, and sole 32 components possibly including midsoles 26, and outsoles 43, having different configurations and dimensions corresponding to a selected article of footwear 22, and the resulting custom article of footwear 22 can be rapidly made or assembled, as desired. Again, this task can be performed by the consumer, or a service provider at the point of purchase in a retail setting or medical facility. Accordingly, similar to the rapid delivery eyewear retail stores and service centers that presently exist, a consumer can now also be provided with a custom article of footwear within minutes.

[0707] In brief, as illustrated in the flow chart shown in FIG. 250, a method of making a custom article of footwear according to the present invention can include the following steps, or their equivalent:

[0708] a) Collecting data relating to a wearer's preferences and the anatomical features and measurements of the wearer's foot;

[0709] b) Creating information and intelligence for selecting and making an article of footwear for the wearer including creating a virtual model and providing the wearer with options; and,

[0710] c) Selecting specific options and creating an article of footwear; and,

[0711] d) Providing the custom article of footwear to the wearer.

[0712] In particular, as illustrated in the flow chart shown in FIG. 251, a method of making a custom article of footwear according to the present invention can include the following steps, or their equivalent:

[0713] a) Collecting data relating to a wearer's preferences and the anatomical features and measurements of the wearer's foot;

[0714] b) Creating from the collected data information and intelligence for making the article of footwear for the wearer;

[0715] c) Providing the information and intelligence to a physical location at which the article of footwear can be made;

[0716] d) Selecting a foot length size;

[0717] e) Selecting a three dimensional foot shape including width and girth dimensions;

[0718] f) Selecting a plurality of footwear components including an upper including closure means, an insole, a spring element, at least one mechanical fastener, and a sole which can be selectively removed and replaced using mechanical engagement means including the at least one mechanical fastener; and,

[0719] g) Removably securing the plurality of footwear components including the upper including closure means, the insole, the spring element, the at least one mechanical fastener, and the sole in functional relation with the mechanical engagement means including the at least one mechanical fastener, and completing the assembly and making of the article of footwear.

[0720] Alternately, if and when an individual's data and final selection is received from a remote site at the Website of a footwear company which practices the present invention, and this information is then possibly transmitted electronically to a manufacturing, assembly center, or distribution center, the selected and required components for the customized article of footwear, or a fully assembled article of footwear can be made available or delivered to a consumer at their home or other designated address within a selected number of working days, e.g., by mail, will call, courier, FEDEX, UPS, or other like means of delivery. Within the continental United States, and many other host countries in which the present invention would be practiced, a customized article of footwear could be caused to be delivered by same day or overnight service, as desired. Accordingly, the present invention teaches a novel method of manufacturing articles of footwear, and also, a novel way of doing both retail and Internet business.

[0721] In brief, as illustrated in the flow chart shown in FIG. 252, a method of conducting business including making and selling a custom article of footwear according to the present invention can include the following steps, or their equivalent:

[0722] a) Collecting data relating to a wearer's preferences and the anatomical features and measurements of the wearer's foot;

[0723] b) Creating information and intelligence for selecting and making an article of footwear for the wearer including creating a virtual model and providing the wearer with options;

[0724] c) Selecting specific options and creating the article of footwear; and,

[0725] d) Providing the custom article of footwear to the wearer.

[0726] In particular, as illustrated in the flow chart shown in FIG. 253, a method of conducting business including making and selling a custom article of footwear according to the present invention can include the following steps, or their equivalent:

[0727] a) Collecting data relating to a wearer's preferences and the anatomical features and measurements of the wearer's foot;

[0728] b) Creating information and intelligence for making the article of footwear for the individual;

[0729] c) Providing the information and intelligence to a physical location at which the article of footwear can be made;

[0730] d) Providing a plurality of footwear components, and a plurality of variations of each footwear component, the footwear components comprising footwear uppers, footwear spring elements, at least one mechanical fastener, and footwear soles which are capable of being assembled to form the custom article of footwear using the at least one mechanical fastener, and each of the components being selectively interchangeable and being removable and replaceable;

[0731] e) Selecting a plurality of footwear components from the provided sources including at least an upper, a spring element, at least one mechanical fastener, and a sole which can be selectively removed and replaced;

[0732] f) Removably securing the plurality of footwear components including the upper, the spring element, and the sole in functional relation with the at least one selected mechanical fastener, thereby making the custom article of footwear; and,

[0733] g) Causing the custom article of footwear to be delivered to a designated address.

[0734] FIG. 45 is a medial cross-sectional side view of an alternate article of footwear 22 having outsole 43 portions affixed directly to the superior spring element 47 in the forefoot area 58 and/or midfoot area 67. Again, the superior spring element 47 can be made of a fiber composite material such as carbon fiber composite or a metal material such as titanium The outsole 43 portions in the forefoot area 58 and also the midfoot area 67 can be affixed directly to the superior spring element 47 by conventional adhesives, and alternately, by self-adhesive means, or mechanical means. As shown in FIG. 47, the upper 23 includes a plurality of openings 72 for accommodating the outsole 43 portions, thus when the superior spring element 47 including the outsole 43 portions is inserted into the upper 23 the outsole 43 portions pass through the plurality of openings 72 as the superior spring element 47 is placed into proper position. An insole 31 can then be inserted into the upper 23, and the article of footwear 22 can then be donned by a wearer. Alternately, the insole 31 can also be affixed to the superior spring element 47 and inserted into the upper 23 as a single unit. Further, a portion of the anterior side 33 of the superior spring element 47 can be inserted into a sleeve 39 of the upper 23 and thereby be retained in position, as discussed and shown in connection with FIG. 15. Moreover, a part including backing 30, or alternately, an anterior spring element 48.1 including a portion of the outsole 43 can be used near the anterior side 33 of the forefoot area 58, and be affixed with the use of mechanical engagement means including male and female parts, e.g., at least one hook 27 and opening 72, and/or a fastener 29, as shown in FIG. 46. The inferior portion of the upper 23 can be made of a strong and long wearing textile material such as KEVLAR®, or a NYLCO® ballistic multi-ply fabric such as “N-915 W” having a protective polyurethane face coating distributed by Worthen Industries, Inc., of 3 East Spit Brook Road, Nashua N.H., and 530 Main Street, Clinton, Mass. These fabric materials can be hand cut, die cut, laser cut, or cut using other conventional means including the possible use of an automatic cutting table.

[0735] FIG. 46 is a medial cross-sectional side view of an alternate article of footwear 22 having outsole portions 43 affixed directly to the superior spring element 47 in the forefoot area 58, and further including a supplemental posterior spring element 49.1 in the rearfoot area 68. The addition of a supplemental posterior spring element 49.1 which can be selected from a range of alternate posterior spring elements 49.1 having different thickness or shapes enables the stiffness and mechanical properties of the superior spring element 47 in the rearfoot area 68 to be easily changed and customized. The possible greater relative thickness of the superior spring element 47 in combination with the supplemental posterior spring element 49.1 can be accommodated by stock-fitting it in the inferior portion of the insole 31, and by engineering the approximate thickness into the desired forefoot versus heel elevation differential. Also shown in FIG. 46 is the use of a part including backing 30, or alternately, an anterior spring element 48.1 including a portion of the outsole 43 near the anterior side 33 of the forefoot area 58. When affixed in position the backing 30, or alternately, an anterior spring element 48.1 thereby traps a portion of the upper 23 between the backing 30 or anterior spring element 48.1 and superior spring element 47. The backing 30, or alternately, an anterior spring element 48.1 can be affixed with the use of mechanical engagement means including male and female parts, e.g., at least one hook 27 and opening 72, and/or a fastener 29, as shown in FIG. 46. The fasteners 29 can be visible from the bottom side as shown in the forefoot area 58, or alternately not be visible, as shown in the rearfoot area 68 in FIG. 46.

[0736] FIG. 47 is a bottom view of the alternate article of footwear 22 shown in FIG. 45 having outsole 43 portions affixed directly to the superior spring element 47 in the forefoot area 58 and midfoot area 67. As shown in FIG. 47, the outsole 43 portions pass through openings 72 in the inferior side 38 of the upper 23. The portions of the upper 23 about the openings 72 can form relatively narrow links or bridges 97 connecting the opposing sides of the upper 23, thus still substantially maintain the shape, and integrity of upper 23. A wide variety of structures and patterns can be used regarding the bridges 97 formed on the inferior side 38 of the upper 23. Shown in the rearfoot area 68 is inferior spring element 50 including posterior outsole element 46, a single fastener 29, and a locating pin 96. The locating pin 96 can be affixed to the inferior spring element 50, or alternately to the superior spring element 47 or posterior spring element 49 and be configured for passing through corresponding mating openings 72 in the various sub-components of the spring element 51. Further, the fastener 29 can be a loose part, or alternately can be affixed to one of the various sub-components of the spring element 51. Moreover, as shown in FIG. 101, the fastener 29 and/or locating pin 96 can have a round transverse cross-section, but at least one of these components preferably has a more complex geometric shape when viewed in a transverse cross-section, such as square, rectangle, pentagon, octagon, or star shape. Accordingly, the insertion of the fastener 29 and/or locating pin 96 can serve to lock the various sub-components of the spring element 50 into a specific geometric orientation so that they cannot be caused to shift or freely rotate about the axis of the fastener 29 and/or locating pin 96 when the sub-components are properly affixed in place.

[0737] FIG. 48 is a medial cross-sectional side view of an alternate article of footwear 22 having outsole 43 portions affixed directly to an anterior spring element 48.1 in the forefoot area 58. Like the embodiment shown in FIG. 16, the superior spring element 47 is affixed to the anterior spring element 48.1 by fasteners 29 thereby trapping and firmly securing an inferior portion of the upper 23 therebetween. However, the use of a single fastener 29 for securing the inferior spring element 50 and numerous gaps 98 between portions of the anterior outsole element 44 are shown in FIG. 48.

[0738] FIG. 49 is a medial cross-sectional side view of an alternate article of footwear 22 having outsole 43 portions affixed directly to an anterior spring element 48.2 in the forefoot area 58 which is affixed to an anterior spacer 55.2 and the superior spring element 47. Again, the shape and thickness of an anterior spacer 55.2 in various locations can be varied so as to create a sloped shape, or other complex shapes along the longitudinal axis 69 or transverse axis 91 of the article of footwear 22. This can determine the relative position of the fulcrum created by the anterior spacer 55.2, but also the angular inclination, magnitude of deflection, and exhibited stiffness of the anterior spring element 48.2. As shown in FIG. 235, the inferior spring element 50 has a flexural axis 59 which is generally transverse to the longitudinal axis 69. Alternately, an inferior spring element 50 having a flexural axis 59 that is diagonal with respect to the longitudinal axis 69 could be used. In addition, as shown in FIG. 100, a midsole element 26 including a fluid-filed bladder can be employed in the space between the anterior spring element 48.2 and the inferior portion of the upper 23. When a gas-filled bladder is used, the gas contained within the bladder can be at ambient atmospheric pressure, or alternately, be pressurized above atmospheric pressure.

[0739] FIG. 50 is an exploded side view of a spring element 51 including a superior spring element 47 having an anterior spring element 48 and a posterior spring element 49, superior posterior spacer 42.1, and inferior posterior spacer 42.2, a fastener 29 including male and female portions, and an inferior spring element 50. The spacers 42.1 and 42.2 can be made in varying thickness and configurations and can be used to change the geometry and configuration of a spring element 51, as desired. Further, the spacers 42.1 and 42.2 can include gripping surfaces for firmly locking the components of a spring element 51 in position when affixed by a fastener 29. Also shown is a fastener 29 affixed in position on the anterior spring element 48 and projecting beyond the inferior surface thereof Accordingly, the inferior portion of this fastener 29 can be approximately flush, or alternately, can slightly protrude beyond the inferior portion of the upper 23 when the anterior spring element 48 is inserted in position As shown, the posterior spring element 49 is positioned superior with respect to the anterior spring element 48 which in turn is positioned superior with respect to the inferior spring element 50.

[0740] FIG. 51 is an exploded side view of a spring element 51 including a superior spring element 47 having an anterior spring element 48 and a posterior spring element 49, superior posterior spacer 42.1, and inferior posterior spacer 42.2, a fastener 29 including male and female portions, and an inferior spring element 50. The spacers 42.1 and 42.2 can be made in varying thickness and configurations and can be used to change the geometry and configuration of a spring element 51, as desired. Further, the spacers 42.1 and 42.2 can include gripping surfaces for firmly locking the components of a spring element 51 in position when affixed by a fastener 29. Also shown is a fastener 29 affixed in position on the anterior spring element 48 that is flush with the inferior surface thereof As shown, the anterior spring element 48 is positioned superior with respect to the posterior spring element 49 which in turn is positioned superior with respect to the inferior spring element 50.

[0741] FIG. 52 is an exploded side view of a spring element 51 including a superior spring element 47 having an anterior spring element 48 and a posterior spring element 49, superior posterior spacer 42.1, and inferior posterior spacer 42.2, a fastener 29 including male and female portions, and an inferior spring element 50. The spacers 42.1 and 42.2 can be made in varying thickness and configurations and can be used to change the geometry and configuration of a spring element 51, as desired. Further, the spacers 42.1 and 42.2 can include gripping surfaces for firmly locking the components of a spring element 51 in position when affixed by a fastener 29. Also shown is a fastener 29 affixed in position on the anterior spring element 48 that is flush with the inferior surface thereof. As shown, the posterior spring element 49 is positioned superior with respect to the inferior spring element 50 which in turn is positioned superior with respect to the anterior spring element 48. Further, the posterior spring element 49 includes a heel counter 24, and the anterior spring element 48 can include a side support 74 on the medial side 35 and/or the lateral side 36.

[0742] FIG. 53 is a bottom plan view of a spring element 51 for use in an article of footwear 22 having a superior spring element 47 and an inferior spring element so having an asymmetrical shape. The inferior spring element 50 has a more complex shape and diminished area on the lateral side 36 relative to the medial side 35, and can thereby exhibit less flexural modulus or stiffness in bending on the lateral side 36.

[0743] FIG. 54 is a bottom plan view of a spring element 51 for use in an article of footwear 22 having a superior spring element 47 and an inferior spring element 50 having an asymmetrical shape. The inferior spring element 50 has a more complex shape and diminished area on the medial side 35 relative to the lateral side 36, and can thereby exhibit less flexural modulus or stiffness in bending on the medial side 35.

[0744] FIG. 55 is a bottom plan view of a spring element 51 for use in an article of footwear 22 having a superior spring element 47 and an inferior spring element 50 having a symmetrical shape. The inferior spring element 50 is affixed to the superior spring element 47 by a single fastener 29 that can be quickly and easily affixed by a wearer in order to service, renew or customize the spring element 51 and associated article of footwear.

[0745] FIG. 56 is a bottom plan view of a spring element 51 for use in an article of footwear 22 having a superior spring element 47 and an inferior spring element 50 having a symmetrical shape and showing an alternate medial mounting position. The superior spring element 47 can include several alternate openings 72 at different positions along the same transverse axis 91 for accommodating the fastener 29. The same inferior spring element 50 can be affixed in several alternate positions, or alternately, various inferior spring elements 50 having a different configurations, such as inferior spring elements having greater width along the transverse axis 91, can be affixed into position. Accordingly, the configuration and mechanical properties of the spring element 51 can be readily adapted in order to customize exhibited performance for an individual wearer. The configuration shown in FIG. 56 can decrease the effective lever arm present at the lateral posterior corner of the inferior spring element 50.

[0746] FIG. 57 is a bottom plan view of a spring element 51 for use in an article of footwear 22 having a superior spring element 47 and an inferior spring element 50 having a symmetrical shape and showing an alternate lateral mounting position. The superior spring element 47 can include several alternate openings 72 at different positions along the same transverse axis 91 for accommodating the fastener 29. The same inferior spring element 50 can be affixed in several alternate positions, or alternately, various inferior spring elements 50 having a different configurations, such as inferior spring elements having greater width along the transverse axis 91, can be affixed into position. Accordingly, the configuration and mechanical properties of the spring element 51 can be readily adapted in order to customize performance for an individual wearer. The configuration shown in FIG. 57 can increase the effective lever arm present at the lateral posterior corner of the inferior spring element 50.

[0747] FIG. 58 is a bottom plan view of a spring element 51 for use in an article of footwear 22 having a superior spring element 47 and an inferior spring element 50 having a symmetrical shape and showing an alternate mounting angle. The fastener 29 and any openings 72 therefore in the spring element 51 can have complex geometric shapes such as pentagon, hexagon, octagon, or star shape, or alternately, the fastener 29 and spring element 51 can include mating male and female surfaces which permit them to engage one another at various angular increments. Accordingly, the configuration and mechanical properties of the spring element 51 can be readily adapted in order to customize performance for an individual wearer. As shown in FIG. 58, the inferior spring element 50 is directed towards the medial side 35, and this will tend to decrease the effective lever arm present at the lateral posterior corner of the inferior spring element 50.

[0748] FIG. 59 is a bottom plan view of a spring element 51 for use in an article of footwear 22 having a superior spring element 47 and an inferior spring element 50 having a symmetrical shape and showing an alternate mounting angle. The fastener 29 and any openings 72 therefore in the spring element 51 can have complex geometric shapes such as pentagon, hexagon, octagon, or star shape, or alternately, the fastener 29 and spring element 51 can include mating male and female surfaces which permit them to engage one another at various selected angular increments. Accordingly, the configuration and mechanical properties of the spring element 51 can be readily adapted in order to customize performance for an individual wearer. As shown in FIG. 59, the inferior spring element 50 is directed towards the lateral side 36, and this will tend to increase the effective lever arm present at the lateral posterior corner of the inferior spring element 50.

[0749] FIG. 60 is a bottom plan view of a spring element 51 for use in an article of footwear 22 having a superior spring element 47 and an inferior spring element 50 having a symmetrical shape and showing an alternate medial mounting position. The inferior spring element 50 can be affixed at one of several alternate positions along the same transverse axis 91, and also be affixed at various selected angular increments.

[0750] FIG. 61 is a bottom plan view of a spring element 51 for use in an article of footwear 22 having a superior spring element 47 and an inferior spring element 50 having a symmetrical shape and showing an alternate lateral mounting position. The inferior spring element 50 can be affixed at one of several alternate positions along the same transverse axis 91, and also be affixed at various selected angular increments.

[0751] FIG. 62 is a bottom plan view of a spring element 51 for use in an article of footwear 22 having a superior spring element 47 and an inferior spring element 50 having a symmetrical shape, and showing an alternate more anterior mounting position. The superior spring element 47 can include several alternate openings 72 and positions along the same longitudinal axis 69 for affixing the inferior spring element 50 thereto. This can permit a given superior spring element 47 and inferior spring element 50 to be used with several different size length articles of footwear, and can also be used to customize the configuration and performance of the spring element 51. Generally, the configuration shown in FIG. 62 will tend to decrease the effective lever arm present at the lateral posterior corner of the inferior spring element 50.

[0752] FIG. 63 is a bottom plan view of a spring element 51 for use in an article of footwear 22 having a superior spring element 47 and an inferior spring element 50 having a symmetrical shape and showing an alternate more posterior mounting position. The superior spring element 47 can include several alternate openings 72 and positions along the same longitudinal axis 69 for affixing the inferior spring element 50 thereto. This can permit a given superior spring element 47 and inferior spring element 50 to be used with several different size length articles of footwear, and can also be used to customize the configuration and performance of the spring element 51. Generally, the configuration shown in FIG. 63 will tend to increase the effective lever arm present at the lateral posterior corner of the inferior spring element 50.

[0753] FIG. 64 is a top plan view of a superior spring element 47 having a surface including affixing means. The superior spring element 47 can include a surface having texture, roughness, or protuberances 99 for enhancing or effecting a mechanical bond. Further, the superior spring element 47 can include a tactified or adhesive surface 100. In this regard, a self-adhesive surface which can be exposed by removal of a peel-ply layer 149 can be used. It can be readily understood that a surface including affixing means can be used with any or all sub-components of a spring element 51, and also the upper 23 of an article of footwear 22.

[0754] FIG. 65 is a bottom plan view of a spring element including a superior spring element 47 and an inferior spring element 50 having a notch 71 and a longitudinal slit 82. As shown, the longitudinal slit 82 partially bisects the inferior spring element 50. When an article of footwear 22 including the inferior spring element 50 is loaded near the lateral posterior corner the stiffness in bending is reduced relative to an otherwise similar inferior spring element 50 which does not include the longitudinal slit 82. As a result, the rate and magnitude of rearfoot pronation experienced by a wearer of an associated article of footwear 22 can be reduced.

[0755] FIG. 66 is a bottom plan view of a spring element 51 including a superior spring element 47 and an inferior spring element consisting of two separate portions 50.1 and 50.2. The configuration and physical properties of each portion 50.1 and 50.2 can thereby be individually varied and customized for optimal performance.

[0756] FIG. 67 is a bottom plan view of a spring element 51 including a superior spring element 47 and an inferior spring element 50 having a notch 71 and diagonal slit 82 that starting on the medial side 35 partially traverses the inferior spring element 50. The diagonal slit 82 creates a line of flexion 54 that reduces the flexural modulus or stiffness in bending exhibited by the inferior spring element 50 at the lateral posterior corner. As a result, the rate and magnitude of rearfoot pronation experienced by a wearer of an associated article of footwear 22 can be reduced.

[0757] FIG. 68 is a bottom plan view of a spring element 51 including a superior spring element 47 and an inferior spring element 50 having two notches 71. The two notches 71 approximately oppose one another forming a line of flexion 54 that is diagonal with respect to the longitudinal axis 69 of the inferior spring element 50. The diagonal line of flexion 54 reduces the flexural modulus or stiffness in bending exhibited by the inferior spring element 50 at the lateral posterior corner. As a result, the rate and magnitude of rearfoot pronation experienced by a wearer of an associated article of footwear 22 can be reduced.

[0758] FIG. 69 is a bottom plan view of a spring element 51 including a superior spring element 47 and an inferior spring element 50 having a slit 82. The slit 82 forms a line of flexion 54 that is diagonal with respect to the longitudinal axis 69 of the inferior spring element 50. The diagonal line of flexion 54 reduces the flexural modulus or stiffness in bending exhibited by the inferior spring element 50 at the lateral posterior corner. As a result, the rate and magnitude of rearfoot pronation experienced by a wearer of an associated article of footwear 22 can be reduced.

[0759] FIG. 70 is a bottom plan view of a spring element 51 including a superior spring element 47 and an inferior spring element 50 having an opening 72. The opening 72 can be circular or oval shaped and is centrally positioned under the weight bearing center of a wearer's heel 57. The presence of opening 72 will decrease the flexural modulus or stiffness in bending and including the exhibited torsional stiffness exhibited by the inferior spring element 50. As a result, the rate and magnitude of rearfoot pronation experienced by a wearer of an associated article of footwear 22 can be reduced.

[0760] FIG. 71 is a bottom plan view of a spring element 51 including a superior spring element 47 and an inferior spring element 50 having an opening 72. The opening 72 is asymmetrical and elongated such as to reduce the flexural modulus or stiffness in bending, and including the torsional stiffness exhibited by the inferior spring element 50 on the lateral side 36 of the line of flexion 54 created thereby. As a result, the rate and magnitude of rearfoot pronation experienced by a wearer of an associated article of footwear 22 can be reduced.

[0761] FIG. 72 is a bottom plan view of a spring element 51 including a superior spring element 47 and an inferior spring element 50 having an opening 72. The opening 72 is asymmetrical and elongated such as to reduce the flexural modulus or stifflness in bending, and including the torsional stiffness exhibited by the inferior spring element 50 on the lateral side 36 of the line of flexion 54 created thereby. As a result, the rate and magnitude of rearfoot pronation experienced by a wearer of an associated article of footwear 22 can be reduced.

[0762] FIG. 73 is a top plan view of a spring element 51 including a superior spring element 47 with parts broken away posterior of the flexural axis 59 in order to reveal a midsole 26 cushioning element and an inferior spring element 50. The midsole 26 cushioning element can include or substantially consist of a fluid-filled bladder 101. It can be readily understood that a fluid-filled bladder 101 can contain a gas, liquid, or viscous material pressurized at ambient atmospheric pressure, or alternately, above atmospheric pressure. Published examples of fluid-filled bladders for possible use in articles of footwear include, but are not limited to: U.S. Pat. Nos. 5,930,918 and 5,363,570 assigned to Converse, Inc.; U.S. Pat. Nos. 5,704,137, 5,191,727, 5,097,607, and 4,934,072 assigned to Brooks Sports, Inc.; U.S. Pat. Nos. 5,718,063, 5,493,792, 5,155,927, and 4,768,295 assigned to Asics Corporation; U.S. Pat. Nos. 5,197,206, 5,197,207, and 5,201,125 assigned to Puma AG. Rudolf Dassler Sport; U.S. Pat. No. 5,598,645 assigned to Adidas International B.V.; U.S. Pat. Nos. 5,369,896, and 6,041,521 assigned to Fila Holdings SpA.; U.S. Pat. Nos. 4,217,705, 4,370,754, 4,441,211, 4,453,271, 4,486,901, 4,513,449, 4,874,640, and 5,235,715 granted to Byron Donzis; U.S. Pat. Nos. 4,926,503, 4,985,931, 5,029,341, 5,035,009, and 5,036,761 granted to J. C. Wingo; U.S. Pat. Nos. 5,572,804, 5,976,451, 6,029,962, and 6,098,313 granted to Joseph Skaja and/or Martyn Shorten; U.S. Pat. Nos. 4,183,156, 4,219,945, 4,271,606, 4,287,250, 4,340,626, 4,906,502, 4,936,029, 5,042,176, 5,083,361, and 5,543,194 granted to Marion F. Rudy; U.S. Pat. No. 6,161,240 granted to Ing-Jing Huang, and, U.S. Pat. Nos. 4,817,304, 5,406,719, 5,592,706, 5,425,184, 5,595,004, 5,625,964, 5,755,001, 5,802,739, 5,833,630, 5,979,078, 5,987,780, 5,993,585, 6,013,340, 6,020,055, 6,055,746, 6,082,025, 6,119,371, 6,127,026, 6,161,240, 6,258,421 B1, 6,321,465 B1, EP 0752216 A3, WO 01/70060 A2, WO 01/70061 A2, WO 01/70062 A2, WO 01/70063 A2, WO 01/70064 A2, and, WO 01/78539 A2, which are assigned to Nike, Inc, all of the recited patents and patent applications in this paragraph hereby being incorporated by reference herein. In particular, fluid-filled bladders including valves that can provide a motion control device such as taught in the above recited patent application WO 01/0061 A2, and fluid-filled bladders comprising a dynamically-controlled cushioning system, as taught in the above recited patent application WO 01/78539 A2, can be used. In the latter case, an article of footwear can include at least one fluid-filled bladder including a plurality of chambers, a control system possibly including a CPU, a pressure detector, and a regulator for modulating the level of fluid communication between different fluid-filled bladders or chambers. It can be readily understood that the fluid-filled bladders taught in the recited patents and patent applications, and the like, could be used in combination with a spring element 51, e.g., various alternate embodiments shown in FIGS. 73-82, 96-100, and 115-117.

[0763] Alternately, a midsole 26 cushioning element can also be made of a foam rubber or plastic material such as polyurethane or ethylene vinyl acetate. In addition, the midsole 26 can simultaneously comprise a posterior spacer 42. As shown in FIG. 73, a midsole 26 cushioning element can occupy substantially the entire space, area, and volume between the superior spring element 47 and the inferior spring element 50 posterior of the flexural axis 59. Alternately, a midsole 26 cushioning element can occupy a portion of the space, area, and volume between a superior spring element 47 and inferior spring element 50, as shown, e.g., in FIGS. 74-82, 96-98, 118-20, and the like.

[0764] FIG. 74 is a top plan view of a spring element 51 including a superior spring element 47 with parts broken away posterior of the flexural axis 59 in order to reveal a midsole 26 cushioning element and an inferior spring element 50. The midsole 26 cushioning element can be made of a fluid-filled bladder 101. It can be readily understood that a fluid-filled bladder 101 can contain a gas, liquid, or viscous material pressurized at ambient atmospheric pressure, or alternately, above atmospheric pressure. Alternately, the midsole 26 cushioning element can be made of a foam rubber or plastic material such as polyurethane or ethylene vinyl acetate. In addition, the midsole 26 can simultaneously comprise a posterior spacer 42. The termination of the midsole 26 at the relatively linear line of flexion 54 which is diagonal with respect to the longitudinal axis 69 creates an additional fulcrum associated with bending of the inferior spring element 50. As shown in FIG. 74, the midsole 26 encompasses substantially the entire space, area, and volume between the superior spring element 47 and the inferior spring element 50 posterior of the flexural axis 59 and anterior of the line of flexion 54. The flexural modulus or stiffness in bending, and including the torsional stiffness exhibited by the inferior spring element 50 on the lateral side 36 and posterior of the line of flexion 54 can thereby be decreased. As a result, the rate and magnitude of rearfoot pronation experienced by a wearer of an associated article of footwear 22 can be reduced.

[0765] FIG. 75 is a top plan view of a spring element 51 including a superior spring element 47 with parts broken away posterior of the flexural axis 59 in order to reveal a midsole 26 cushioning element and an inferior spring element 50. The midsole 26 cushioning element can be made of a fluid-filled bladder 101. It can be readily understood that a fluid-filled bladder 101 can contain a gas, liquid, or viscous material pressurized at ambient atmospheric pressure, or alternately, above atmospheric pressure. Alternately, the midsole 26 cushioning element can be made of a foam rubber or plastic material such as polyurethane or ethylene vinyl acetate. In addition, the midsole 26 can simultaneously comprise a posterior spacer 42. The termination of the midsole 26 at the arcuate line of flexion 54 creates an additional fulcrum associated with bending of the inferior spring element 50. As shown in FIG. 74, the midsole 26 encompasses substantially the entire space, area, and volume between the superior spring element 47 and the inferior spring element 50 posterior of the flexural axis 59 and anterior of the arcuate line of flexion 54. The flexural modulus or stiffness in bending, and including the torsional stiffness exhibited by the inferior spring element 50 on the lateral side 36 and posterior of the line of flexion 54 can thereby be decreased. As a result, the rate and magnitude of rearfoot pronation experienced by a wearer of an associated article of footwear 22 can be reduced.

[0766] FIG. 76 is a top plan view of a spring element 51 including a superior spring element 47 with parts broken away posterior of the flexural axis 59 in order to reveal a midsole 26 cushioning element and an inferior spring element 50. The midsole 26 cushioning element can be made of a fluid-filled bladder 101. It can be readily understood that a fluid-filled bladder 101 can contain a gas, liquid, or viscous material pressurized at ambient atmospheric pressure, or alternately, above atmospheric pressure. Alternately, the midsole 26 cushioning element can be made of a foam rubber or plastic material such as polyurethane or ethylene vinyl acetate. In addition, the midsole 26 can simultaneously comprise a posterior spacer 42. The termination of the midsole 26 at the arcuate line of flexion 54 creates an additional fulcrum associated with bending of the inferior spring element 50. As shown in FIG. 74, the midsole 26 encompasses substantially the entire space, area, and volume between the superior spring element 47 and the inferior spring element 50 posterior of the flexural axis 59 and anterior of the arcuate line of flexion 54. The flexural modulus or stiffness in bending, and including the torsional stiffness exhibited by the inferior spring element 50 on the lateral side 36 and posterior of the line of flexion 54 can thereby be decreased. As a result, the rate and magnitude of rearfoot pronation experienced by a wearer of an associated article of footwear 22 can be reduced.

[0767] FIG. 77 is a top plan view of a spring element 51 including a superior spring element 47 with parts broken away posterior of the flexural axis 59 in order to reveal a column shaped midsole 26 cushioning element and an inferior spring element 50. Again, a midsole 26 cushioning element can consist of a fluid-filled bladder, or a foam material. As shown, the single midsole 26 cushioning element has an oval or elliptical shape in a top plan view. However, it can be readily understood that a single midsole 26 cushioning element can have other geometric shapes. As shown, the midsole 26 cushioning element is located on the medial side 35. The relative flexural modulus or stiffness in bending, and including the torsional stiffness exhibited by the inferior spring element 50 on the lateral side 36 can thereby be decreased. As a result, the rate and magnitude of rearfoot pronation experienced by a wearer of an associated article of footwear 22 can be reduced.

[0768] FIG. 78 is a top plan view of a spring element 51 including a superior spring element 47 with parts broken away posterior of the flexural axis 59 in order to reveal two column shaped midsole 26 cushioning elements and an inferior spring element 50. Again, a midsole 26 cushioning element can consist of a fluid-filled bladder, or a foam material. As shown, the two midsole 26 cushioning elements have a circular shape in a top plan view. However, it can be readily understood that the two midsole 26 cushioning elements can have other geometric shapes. As shown, the midsole 26 cushioning elements are located on the medial side 35. The relative flexural modulus or stiffness in bending, and including the torsional stiffness exhibited by the inferior spring element 50 on the lateral side 36 can thereby be decreased. As a result, the rate and magnitude of rearfoot pronation experienced by a wearer of an associated article of footwear 22 can be reduced.

[0769] FIG. 79 is a top plan view of a spring element 51 including a superior spring element 47 with parts broken away posterior the flexural axis 59 in order to reveal three column shaped midsole 26 cushioning elements and an inferior spring element 50. Again, a midsole 26 cushioning element can consist of a fluid-filled bladder, or a foam material. As shown, the three midsole 26 cushioning elements have a circular shape in a top plan view. However, it can be readily understood that the three midsole 26 cushioning elements can have other geometric shapes. As shown, the midsole 26 cushioning elements are located on the medial side 35. The relative flexural modulus or stiffness in bending, and including the torsional stiffness exhibited by the inferior spring element 50 on the lateral side 36 can thereby be decreased. As a result, the rate and magnitude of rearfoot pronation experienced by a wearer of an associated article of footwear 22 can be reduced.

[0770] FIG. 80 is a top plan view of a spring element 51 including a superior spring element 47 with parts broken away posterior of the flexural axis 59 in order to reveal six column shaped midsole 26 cushioning elements and an inferior spring element 50. Again, a midsole 26 cushioning element can consist of a fluid-filled bladder, or a foam material. As shown, the column shaped midsole 26 cushioning elements are symmetrically positioned on both the medial side 35 and lateral side 36, and the midsole 26 cushioning elements have a circular shape in a top plan view. However, it can be readily understood that the midsole 26 cushioning elements can have other geometric shapes. If desired, at least the posteriormost midsole 26 cushioning element on the lateral side 36 can be made of a composition as to exhibit less stiffness in compression than those on the medial side 35. As a result, the rate and magnitude of rearfoot pronation experienced by a wearer of an associated article of footwear 22 can be reduced.

[0771] FIG. 81 is a top plan view of a spring element 51 including a superior spring element 47 with parts broken away posterior of the flexural axis 59 in order to reveal five column shaped midsole 26 cushioning elements and an inferior spring element 50. Again, a midsole 26 cushioning element can consist of a fluid-filled bladder, or a foam material. The midsole 26 cushioning elements have a circular shape in a top plan view. However, it can be readily understood that the midsole 26 cushioning elements can have other geometric shapes. As shown, three of the column shaped midsole 26 cushioning elements are positioned on the medial side 35 and two of the column shaped midsole 26 cushioning elements are positioned on the lateral side 36. The relative flexural modulus or stiffness in bending, and including the torsional stiffness exhibited by the inferior spring element 50 on the lateral side 36 can thereby be decreased. As a result, the rate and magnitude of rearfoot pronation experienced by a wearer of an associated article of footwear 22 can be reduced.

[0772] FIG. 82 is a top plan view of a spring element 51 including a superior spring element 47 with parts broken away posterior of the flexural axis 59 in order to reveal a midsole 26 cushioning element including an opening 72 and an inferior spring element 50. Again, a midsole 26 cushioning element can consist of a fluid-filed bladder, or alternately and as shown in FIG. 82, the midsole 26 cushioning element can consist of a foam material. As shown, the midsole 26 cushioning element encompasses a significant portion of the space, area, and volume between the superior spring element 47 and the inferior spring element 50 posterior of the flexural axis 59. However, the void space or opening 72 is asymmetrically positioned closer to the lateral side 36 than the medial side 35, thus the flexural modulus or stiffness in bending, and including the torsional stiffness exhibited by the inferior spring element 50 on the lateral side 36 can thereby be decreased. As a result, the rate and magnitude of rearfoot pronation experienced by a wearer of an associated article of footwear 22 can be reduced.

[0773] FIG. 83 is a top plan view of a spring element 51 including a superior spring element 47 with parts broken away posterior of the flexural axis 59 in order to reveal an inferior spring element 50 having convex peak 92 portions and concave valley 93 portions extending longitudinally on the medial side. The presence of convex peak 92 portions and concave valley 93 portions can increase the flexural modulus or stiffness in bending, and including the torsional stiffness exhibited by the inferior spring element 50 on the medial side 35 relative to the lateral side 36. As a result, the rate and magnitude of rearfoot pronation 6 n experienced by a wearer of an associated article of footwear 22 can be reduced.

[0774] FIG. 84 is a cross-sectional view along line 84-84 of the inferior spring element 50 shown in FIG. 83 having convex peak 92 portions and concave valley 93 portions.

[0775] FIG. 85 is a cross-sectional view similar to that shown in FIG. 84 of an alternate inferior spring element 50 having an extension 94 on the medial side 35. As shown, the extension 94 projects both above and below the two planes formed by the superior side 37 and inferior side 38 of the inferior spring element 50. The presence of an extension 94 can increase the flexural modulus or stiffness in bending, and including the torsional stiffness exhibited by the inferior spring element 50 on the medial side 35 relative to the lateral side 36. As a result, the rate and magnitude of rearfoot pronation experienced by a wearer of an associated article of footwear 22 can be reduced.

[0776] FIG. 86 is a cross-sectional view similar to that shown in FIG. 84 of an alternate inferior spring element 50 having an extension 94 on the medial side 35. As shown, the extension 94 projects above the plane formed by the superior side 37 of the inferior spring element 50. The presence of an extension 94 can increase the flexural modulus or stiffness in bending, and including the torsional stiffness exhibited by the inferior spring element 50 on the medial side 35 relative to the lateral side 36. As a result, the rate and magnitude of rearfoot pronation experienced by a wearer of an associated article of footwear 22 can be reduced.

[0777] FIG. 87 is a cross-sectional view similar to that shown in FIG. 84 of an alternate inferior spring element 50 having an extension 94 on the medial side 35. As shown, the extension 94 projects below the plane formed by the inferior side 38 of the inferior spring element 50. The presence of an extension 94 can increase the flexural modulus or stiffness in bending, and including the torsional stiffness exhibited by the inferior spring element 50 on the medial side 35 relative to the lateral side 36. As a result, the rate and magnitude of rearfoot pronation experienced by a wearer of an associated article of footwear 22 can be reduced.

[0778] FIG. 88 is a cross-sectional view similar to that shown in FIG. 84 of an alternate inferior spring element 50 having concave peaks 92 and convex valleys 93 on the superior side 37. The presence of convex peaks 92 and concave valleys 93 can increase the flexural modulus or stiffness in bending, and including the torsional stiffness exhibited by the inferior spring element 50 on the medial side 35 relative to the lateral side 36. As a result, the rate and magnitude of rearfoot pronation experienced by a wearer of an associated article of footwear 22 can be reduced.

[0779] FIG. 89 is a cross-sectional view similar to that shown in FIG. 84 of an alternate inferior spring element 50 having greater thickness on the medial side 35. The presence of greater thickness can increase the flexural modulus or stiffness in bending, and including the torsional stiffness exhibited by the inferior spring element 50 on the medial side 35 relative to the lateral side 36. As a result, the rate and magnitude of rearfoot pronation experienced by a wearer of an associated article of footwear 22 can be reduced.

[0780] FIG. 90 is a top plan view of a spring element 51 including a superior spring element 47 with parts broken away posterior of the flexural axis 59 in order to reveal an inferior spring element 50 having convex peaks 92 and concave valleys 93 extending transversely from the medial side 35. The presence of convex peaks 92 and concave valleys 93 can increase the flexural modulus or stiffness in bending, and including the torsional stiffness exhibited by the inferior spring element 50 on the medial side 35 relative to the lateral side 36. As a result, the rate and magnitude of rearfoot pronation experienced by a wearer of an associated article of footwear 22 can be reduced.

[0781] FIG. 91 is a side view of a spring element 51 similar to that shown in FIG. 90 including a superior spring element 47 and an inferior spring element 50 including inserts 95 such as dowels and convex peaks 92 and concave valleys 93. An insert 95 can consist of a relatively light-weight material which can create or quickly build a desired generally planar thickness or convex peak 92 when substantially encapsulated by a fiber composite material. The presence of convex peaks 92 and concave valleys 93 can increase the flexural modulus or stiffness in bending, and including the torsional stiffness exhibited by the inferior spring element 50 on the medial side 35 relative to the lateral side 36. As a result, the rate and magnitude of rearfoot pronation experienced by a wearer of an associated article of footwear 22 can be reduced.

[0782] FIG. 92 is a side view of a spring element 51 including a superior spring element 47 and an inferior spring element 50 including convex peaks 92 and concave valleys 93. The presence of convex peaks 92 and concave valleys 93 can increase the flexural modulus or stiffness in bending, and including the torsional stiffness exhibited by the inferior spring element 50 on the medial side 35 relative to the lateral side 36. As a result, the rate and magnitude of rearfoot pronation experienced by a wearer of an associated article of footwear 22 can be reduced.

[0783] FIG. 93 is a top perspective view of a spring element 51 including a superior spring element 47 and an inferior spring element 50 showing a cross-section taken along line 94—94. The inferior spring element 50 can be affixed to the superior spring element 47 at one or more locations proximate its anterior side, and the inferior spring element 50 can then gradually and evenly project downwards from the superior spring element 47 on the medial side 35 and lateral side 36. Accordingly, the configuration and relationship between the inferior spring element 50 and superior spring element 47 can appear as shown in the transverse cross-sectional view shown in FIG. 94.

[0784] FIG. 94 is a cross-sectional view of the spring element 51 shown in FIG. 93 taken along line 94—94.

[0785] FIG. 95 is a transverse cross-sectional view of an alternate spring element 51 taken along a line similar to 94—94 shown in FIG. 93. Again, the inferior spring element 50 can be affixed to the superior spring element 47 at one or more locations near its anterior side. However, the inferior spring element 50 projects downwards from the superior spring element 47 on the medial side 35 unevenly relative to the lateral side 36. Accordingly, the configuration and relationship between the inferior spring element 50 and superior spring element 47 can appear as shown in the transverse cross-sectional view shown in FIG. 95. As shown, the inferior spring element 50 is sloped upwards from the lateral side 36 to the medial side 35. Accordingly, when the inferior spring element 50 is loaded at the lateral and posterior corner during the walking or running gait cycle, the inferior spring element 50 can exhibit greater counter-clockwise movement and torsional stiffness. In particular, when the inferior spring element 50 is affixed near its anterior end at a single and central location, the medial side 35 of the inferior spring element 50 can move counter-clockwise and exert force upon the support surface thereby actively posting and supporting the medial side 35.

[0786] FIG. 96 is a longitudinal cross-sectional medial side view of an alternate article of footwear 22 including a midsole 26 cushioning element affixed to both the superior spring element 47 and the inferior spring element 50. Alternately, the midsole 26 cushioning element can be affixed only to the superior spring element 47, or alternately, the midsole 26 cushioning element can only be affixed to the inferior spring element 50. The midsole 26 cushioning element shown in FIG. 96 can generally resemble that shown in FIG. 77.

[0787] FIG. 97 is a longitudinal cross-sectional medial side view of an alternate article of footwear 22 including two midsole 26 cushioning elements affixed to the superior spring element 47. Alternately, the midsole 26 cushioning element can be affixed only to the inferior spring element 50, or alternately, the midsole 26 cushioning element can be affixed to both the inferior spring element 50 and superior spring element 47. The midsole 26 cushioning element shown in FIG. 97 can generally resemble those shown in FIG. 78.

[0788] FIG. 98 is a longitudinal cross-sectional medial side view of an alternate article of footwear 22 including three midsole 26 cushioning elements affixed to the inferior spring element 50. Alternately, the midsole 26 cushioning element can be affixed only to the superior spring element 47, or alternately, the midsole 26 cushioning element can be affixed to both the inferior spring element 50 and superior spring element 47. The midsole 26 cushioning elements shown in FIG. 98 can generally resemble those shown in FIGS. 79, 80, 81. In addition, the height of the various midsole 26 cushioning elements can be the same, or alternately, the height of the midsole 26 cushioning elements can vary, thus introducing both a fulcrum and a distinct change in the exhibited stiffness of the spring element 51 in various stages. Accordingly, one or more of the midsole 26 cushioning elements can be loaded at the same time, or at different times during the gait cycle. As a result, the rate and magnitude of rearfoot pronation experienced by a wearer of an associated article of footwear 22 can be reduced.

[0789] FIG. 99 is a longitudinal cross-sectional medial side view of an alternate article of footwear 22 including a midsole 26 cushioning element comprising a fluid-filled bladder affixed between the superior spring element 47 and the inferior spring element 50. The midsole 26 cushioning element comprising a fluid-filled bladder 101 can generally resemble that shown in FIG. 73. It can be readily understood that a fluid-filled bladder 101 can contain a gas, liquid, or viscous material pressurized at ambient atmospheric pressure, or alternately, above atmospheric pressure. As shown in FIG. 73, the midsole 26 encompasses substantially the entire space, area, and volume between the superior spring element 47 and the inferior spring element 50 posterior of the flexural axis 59. However, the midsole 26 can encompass a portion of the space, area, and volume between the superior spring element 47 and the inferior spring element 50 posterior of the flexural axis 59, as shown in FIGS. 74-82, and many other configurations are possible.

[0790] FIG. 100 is a longitudinal cross-sectional medial side view of an alternate article of footwear 22 including a midsole 26 cushioning element comprising a first posterior fluid-filled bladder 101.1 affixed between the superior spring element 47 and the inferior spring element 50 in the rearfoot area 68, and a second anterior fluid-filled bladder 101.2 affixed between the superior spring element 47 and an inferior anterior spring element 48.2 in the forefoot area 58. The alternate article of footwear 22 shown in FIG. 100 can be generally similar to that shown in FIG. 49, but with the addition of fluid-filled bladders 101.1 and 101.2. It can be readily understood that a fluid-filled bladder can contain a gas, liquid, or viscous material pressurized at ambient atmospheric pressure, or alternately, above atmospheric pressure. As shown in FIG. 100, the midsole 26 cushioning elements encompass substantially the entire space, area, and volume between the superior spring element 47 and the inferior spring element 50 posterior of the flexural axis 59, but also substantially the entire space, area, and volume between the superior spring element 47 and the inferior anterior spring element 48.2 posterior of the anterior position of attachment behind the anterior spacer 55.2. Alternately, the midsole 26 cushioning elements can encompass only a portion of the space, area, and volume between the superior spring element 47 and the inferior spring element 50, and/or the superior spring element 47 and the inferior anterior spring element 48.2, thus many other configurations are possible.

[0791] FIG. 101 is a perspective exploded view of a spring element 51 including a superior spring element 47, and an inferior spring element 50 showing a fastener 29 and a locating pin 96. The superior spring element 47 and inferior spring element 50 can both include registered openings 72 having a shape such as a square, rectangle, diamond, triangle, pentagon, octagon star, or other non-circular complex shape which can thereby be mechanically engaged and locked in position with respect to the fastener 29. In addition, a locating pin 96 can also be used to align and maintain the superior spring element 47 and inferior spring element 50 in proper position. The locating pin 96 can possibly be affixed to either the superior spring element 47 or inferior spring element 50, and can possibly pass through the upper 23 of an article of footwear 22 before engaging a corresponding component of the spring element 51.

[0792] FIG. 102 is a bottom plan view of a spring element 51 including a superior spring element 51 and an inferior spring element 50 having an insert 95. The insert 95 can be made of metal such as titanium or spring steel and can serve to increase the flexural modulus or stiffness in bending and also the torsional stiffness of the inferior spring element 50 on the medial side 35 relative to more substantial use of a fiber composite material 102 on the lateral side 36. The insert 95 can be partially or completely encapsulated by a fiber composite material 102.

[0793] FIG. 103 is a bottom plan view of a spring element 51 including a superior spring element 47 and an inferior spring element 50 having a different fiber composite material 102.1 on the medial side 35 than the fiber composite material 102.2 used on the lateral side 36. For example, a unidirectional carbon fiber composite material 102.1 could be used on the medial side 35, whereas a woven carbon fiber composite material 102.2 could be used on the lateral side 36. This can serve to increase the flexural modulus or stiffness in bending and also the torsional stiffness of the inferior spring element 50 on the medial side 35 relative to the lateral side 36.

[0794] FIG. 104 is a bottom plan view of a spring element 51 including a superior spring element 47 and an inferior spring element 50 having different fiber composite materials on the medial side 35 than on the lateral side 36. For example, a unidirectional carbon fiber composite material could be used on the medial side 35, whereas a fiberglass material could be used on the lateral side 36. This can serve to increase the flexural modulus or stiffness in bending and also the torsional stiffness of the inferior spring element 50 on the medial side 35 relative to the lateral side 36.

[0795] FIG. 105 is a bottom plan view of a spring element 51 including a superior spring element 47 and an inferior spring element 50 having different fiber composite material 102 orientations on the medial side 35 than on the lateral side 36. For example, on the medial side 35, when an inferior spring element 50 substantially consisting of uni-directional carbon fiber composite material 102 is being constructed, the direction of the fibers in one layer can be orientated parallel with respect to the longitudinal axis 69 or at 0 degrees, and the next layer can be orientated at about 45 degrees to the right, and then the next layer at about 45 degrees to the left. This sequence can then be repeated until the part is constructed to the desired thickness. If desired, on the lateral side 36, a greater number of the layers can be orientated between 0 degrees and 45 or 90 degrees right, as opposed to 0 degrees and 45 or 90 degrees left, as this can reduce the flexural modulus or stiffness in bending exhibited by the inferior spring element 50, since uni-directional carbon fiber composite materials normally exhibit greatest stiffness when bending at 90 degrees relative to the orientation of the fibers. This can serve to increase the flexural modulus or stiffness in bending and also the torsional stiffness of the inferior spring element 50 on the medial side 35 relative to the lateral side 36, and create a line a flexion 54.

[0796] FIG. 106 is a bottom plan view of a spring element 51 including a superior spring element 47 and an inferior spring element 50 having an uni-directional fiber composite material 102.1 orientated differently on the medial side 35, lateral side 36, and posterior side 34, than in the middle portion 105. In this alternate embodiment, the middle portion 105 can be constructed by alternating the orientation of the layers at 0 degrees, 45 degrees right, and 45 degrees left in a continuous sequences, whereas the medial side 35, lateral side 36, and posterior side 34 can omit layers at 45 degrees left and right, and instead possibly use a greater number of layers at 0 degrees. The resulting inferior spring element 50 can exhibit less stiffness in bending at the medial, lateral and posterior sides and edges than in the middle 105. This could be advantageous with regards to reducing the stiffness in bending even if not the actual length of the effective lever arm created by the sole of an associated article of footwear 22, thus reduce the magnitude of pronation or supination exhibited in certain lateral movement applications of the article of footwear such as tennis, volleyball, or basketball. However, a dramatic reduction in the stiffness of the sole about the medial side 35, lateral side 36, and posterior sides 34 can at some point prove counter-productive and result in instability, and so ideally, the stiffness variable should be optimized and customized for use by an individual wearer for use in the particular targeted activity.

[0797] FIG. 107 is a top plan view of a spring element 51 including a superior spring element 47 and an inferior spring element 50 made of a metal material. The metal material can substantially consist of a titanium alloy, or spring steel. The inferior spring element 50 can be cut and formed in a single part from a flat sheet stock of titanium alloy by bending the piece about the flexural axis 59, or alternately, the inferior spring element 50 can be stamped, forged, cast or molded into the desired shape.

[0798] FIG. 108 is a cross-sectional view of the spring element 51 shown in FIG. 107 taken along line 108—108.

[0799] FIG. 109 is a bottom plan view of a spring element 51 including a superior spring element 47 and an inferior spring element 50 made of a metal material The metal material can substantially consist of a titanium alloy, or spring steel. The spring element 51 can be cut and formed in a single part from a flat sheet stock of titanium alloy by bending the piece about a generally longitudinal flexural axis 59.1 on the medial side 35 and also about a generally longitudinal flexural axis 59.2 on the lateral side 36. Alternately, the inferior spring element 50 can be stamped, forged, cast or molded into the desired shape. The inferior spring element 50 can be have relatively greater separation from the superior spring element 47 near the posterior side 34 than near the anterior side 33.

[0800] FIG. 110 is a cross-sectional view of the spring element 51 shown in FIG. 109 taken along line 110—110.

[0801] FIG. 111 is a bottom plan view of a spring element 51 including a superior spring element 47 and an inferior spring element 50 having a symmetrical cantilever shape. The middle portion 105 of the inferior spring element 50 is generally planar and can lie flat 14 against a portion of the superior spring element 47 when the two components are affixed together. However, the medial side 35, lateral side 36, and posterior side 34 of the inferior spring element 50 descend in an arcuate fashion from the middle portion 105 to form a cantilever shape whereby the inferior spring element 50 has a concave configuration when viewed in a transverse cross-section, as shown in FIG. 112.

[0802] FIG. 112 is a cross-sectional view of the spring element 51 shown in FIG. 111 taken along line 112—112, and is shown with the superior side 37 up.

[0803] FIG. 113 is a bottom plan view of a spring element 51 including a superior spring element 47 and an inferior spring element 50 having an asymmetrical cantilever shape. The middle portion 105 of the inferior spring element 50 is generally planar and can lie flat against a portion of the superior spring element 47 when the two components are affixed together. However, the medial side 35, lateral side 36, and posterior side 34 of the inferior spring element 50 descend in an arcuate fashion from the middle portion 105 to form a cantilever shape whereby the inferior spring element 50 has a concave configuration when viewed in a transverse cross-section, as shown in FIG. 114.

[0804] FIG. 114 is a cross-sectional view of the spring element 51 shown in FIG. 113 taken along line 114—114, and shown with the superior side 37 up. It can be seen by comparing FIGS. 111 and 133, and their corresponding cross-sectional views shown in FIGS. 112 and 114, that the inferior spring element 50 shown in FIGS. 113 and 114 has an asymmetric shape. The length of the lever arm of the inferior spring element 50 on the medial side 35 is shorter than that present on the lateral side 36, and at the lateral and posterior corner. This can serve to enhance the flexural modulus or stiffness in bending and also the torsional stiffness of the inferior spring element 50 on the medial side 35 relative to the lateral side 36, and create a line a flexion 54.

[0805] FIG. 115 is a cross-sectional view of the spring element 51 shown in FIG. 74 taken along line 115—115. A midsole 26 cushioning element consisting of a fluid-filled bladder 101 is located between the superior spring element 47 and inferior spring element 50. The fluid-filled bladder 101 can extend posteriorly to greater degree on the medial side 35 in order to create differential stiffness relative to the lateral side 36 and rearfoot strike zone.

[0806] FIG. 116 is a cross-sectional view of the spring element 51 shown in FIG. 75 taken along line 116—116. A midsole 26 cushioning element consisting of a fluid-filled bladder 101 is located between the superior spring element 47 and inferior spring element 50. The fluid-filled bladder 101 can extend posteriorly to greater degree on the medial side 35 in order to create differential stiffness relative to the lateral side 36 and rearfoot strike zone.

[0807] FIG. 117 is a cross-sectional view of the spring element 51 shown in FIG. 74 taken along line 117—117. A midsole 26 cushioning element consisting of a fluid-filled bladder 101 is located between the superior spring element 47 and inferior spring element 50. The fluid-filled bladder 101 can extend posteriorly on the medial side 35 in order to create differential stiffness relative to the lateral side 36 and rearfoot strike zone.

[0808] FIG. 118 is a cross-sectional view of an alternate spring element 51 taken along a line similar to 115 shown in FIG. 74. In this alternate embodiment, a midsole 26 cushioning element consisting of a foam material is located between the superior spring element 47 and inferior spring element 50 on the medial side 35. The inferior spring element 50 is affixed to the superior spring element 47 on the medial side 35, and the inferior spring element 50 then descends to a position of maximum separation from the superior spring element 47 at the lateral side 36. The midsole 26 cushioning element consisting of foam material supports the spring element 51 on the medial side 35, and an outsole 43 can underlie at least a portion of the foam material and spring element 51.

[0809] FIG. 119 is a cross-sectional view of an alternate spring element 51 taken along a line similar to 116 shown in FIG. 75. In this alternate embodiment, a midsole 26 cushioning element consisting of a foam material is located between the superior spring element 47 and inferior spring element 50 on the medial side 35. The inferior spring element 50 is affixed to the superior spring element 47 on the medial side 35, and the inferior spring element 50 then descends to a position of maximum separation from the superior spring element 47 at the lateral side 36. The midsole 26 cushioning element consisting of foam material supports the spring element 51 on the medial side 35, and an outsole 43 can underlie at least a portion of the foam material and spring element 51.

[0810] FIG. 120 is a cross-sectional view of an alternate spring element 51 taken along a line similar to 117 shown in FIG. 76. In this alternate embodiment, a midsole 26 cushioning element consisting of a foam material is located between the superior spring element 47 and inferior spring element 50 on the medial side 35. The inferior spring element 50 is affixed to the superior spring element 47 on the medial side 35, and the inferior spring element 50 then descends to a position of maximum separation from the superior spring element 47 at the lateral side 36. The midsole 26 cushioning element consisting of foam material supports the spring element 51 on the medial side 35, and an outsole 43 can underlie at least a portion of the foam material and spring element 51.

[0811] FIG. 121 is a side view of a spring element 51 including a superior spring element 47 including a heel counter 24, side support 74 and an inferior spring element 50.

[0812] FIG. 122 is a cross-sectional view taken along line 122—122 of the superior spring element 47 shown in FIG. 121. The superior spring element 47 includes a side support 74 on the medial side 35.

[0813] FIG. 123 is a cross-sectional view taken along line 123—123 of the superior spring element 47 shown in FIG. 121. The superior spring element 47 includes a heel counter 24 that provides support to both the medial side 35 and lateral side 36.

[0814] FIG. 124 is a cross-sectional view of an alternate superior spring element 47 taken along a line similar to 122 shown in FIG. 121. The superior spring element 47 includes side supports 74 on both the medial side 35 and lateral side 36.

[0815] FIG. 125 is a cross-sectional view of an alternate superior spring element 47 taken along a line similar to 122 shown in FIG. 121. The superior spring element 47 has an arcuate shape generally corresponding to the anatomical shape of a wearer's foot and includes side supports 74 on both the medial side 35 and lateral side 36.

[0816] FIG. 126 is a bottom plan view of a spring element 51 generally similar to that shown in a side view in FIG. 49 including a superior spring element 47, an inferior anterior spring element 48.2, and an inferior spring element 50. The inferior anterior spring element 48.2 is affixed by three fasteners 29 directly to the superior spring element 47 near the anterior side 33. The inferior spring element 50 is also affixed to the superior spring element 47 by a fastener 29. The approximate position of the metatarsal-phalangeal joints of a wearer's foot corresponding to the spring element 51 and an associated article of footwear 22 is normally slightly less than 70 percent of the length of an article of footwear 22 as measured from the posterior side 34 on the medial side 35, and greater than 60 percent of the length of an article of footwear 22 as measured from the posterior side 34 on the lateral side 36, but still somewhat less than on the medial side 35, as shown by line 104.

[0817] FIG. 127 is a bottom plan view of a spring element 51 generally similar to that shown in a side view in FIG. 49 including a superior spring element 47, an inferior anterior spring element 48.2, and an inferior spring element 50. The inferior anterior spring element 48.2 is affixed by three fasteners 29 to the anterior spacer 55.2 and the superior spring element 47 near the anterior side 33. As shown in FIG. 127, the posteriormost portion of the anterior spacer 55.2 upon which the superior spring element 47 and inferior anterior spring element 48.2 bear is shown by a dashed line that is anterior and parallel to line 104 indicating the approximate position of the metatarsal-phalangeal joints.

[0818] FIG. 128 is a bottom plan view of a spring element 51 generally similar to that shown in a side view in FIG. 49 including a superior spring element 47, an inferior anterior spring element 48.2, and an inferior spring element 50. The anterior spring element 48.2 is affixed by three fasteners 29 to the anterior spacer 55.2 and the superior spring element 47 near the anterior side 33. As shown in FIG. 127, the posteriormost portion of the anterior spacer 55.2 upon which the superior spring element 47 and inferior anterior spring element 48.2 bear is shown by a dashed line that converges towards line 104 on the medial side 35.

[0819] FIG. 129 is a bottom plan view of a spring element 51 generally similar to that shown in a side view in FIG. 49 including a superior spring element 47, an inferior anterior spring element 48.2, and an inferior spring element 50. The inferior anterior spring element 48.2 is affixed by three fasteners 29 to the anterior spacer 55.2 and the superior spring element 47 near the anterior side 33. As shown in FIG. 127, the posteriormost portion of the anterior spacer 55.2 upon which the superior spring element 47 and inferior anterior spring element 48.2 bear is shown by a dashed line that converges towards line 104 on the medial side 35 more dramatically than the spring element 51 embodiment shown in FIG. 128.

[0820] FIG. 130 is a bottom plan view of a spring element 51 generally similar to that shown in a side view in FIG. 49 including a superior spring element 47, an inferior anterior spring element 48.2, and an inferior spring element 50. The inferior anterior spring element 48.2 is affixed by one fastener 29 directly to the superior spring element 47 near the anterior side 33.

[0821] FIG. 131 is a bottom plan view of a spring element 51 generally similar to that shown in a side view in FIG. 49 including a superior spring element 47, an inferior anterior spring element 48.2, and an inferior spring element 50. The inferior anterior spring element 48.2 is affixed by one fastener 29 directly to the superior spring element 47 near the anterior side 33. However, the inferior anterior spring element 48.2 has less overall anterior to posterior length, and in particular, less area posterior of line 104 than the embodiment shown in FIG. 130.

[0822] FIG. 132 is a bottom plan view of a spring element 51 including a superior spring element 47, and an inferior spring element 50 having a U-shape. The inferior spring element 50 can be affixed to the superior spring element 47 with two fasteners and includes a notch 71 that can extend to various lengths in the middle portion 105 thereby imparting to the inferior spring element 50 a U-shape.

[0823] FIG. 133 is a bottom plan view of a spring element 51 including a superior spring element 47, and an inferior spring element 50 having a J-shape. The inferior spring element 50 can be affixed to the superior spring element 47 with two fasteners and includes a notch 71 that can extend to various lengths in the middle portion 105 thereby imparting to the inferior spring element 50 a J-shape.

[0824] FIG. 134 is a bottom plan view of a spring element 51 including a superior spring element 47 and an inferior spring element 50 including portions having a gently curved convex shape. The inferior spring element 50 can be curved upwards about a portion of the medial side 35, lateral side 36, and posterior side 34. This can increase the exhibited stiffness of the inferior spring element 50 about the sides in these areas. As result, the generally planar middle portion 105 of the inferior spring element 50 in the area anterior of the flexural axis 59 can assume most of the work associated with flexion and torsion. In some applications, the use of a curved convex structure or other method of increasing the stiffness of a specific portion of a spring element 51 can possibly be used to enhance the stability and performance of an article of footwear.

[0825] FIG. 135 is a cross-sectional view of the spring element 51 shown in FIG. 134 taken along line 135—135 showing a superior spring element 47 having a gently curved convex shape so as to better accommodate the shape of a wearer's heel, and an inferior spring element 50 having a similar convex shape including an outsole 43 affixed thereto.

[0826] FIG. 136 is a cross-sectional view of an alternate spring element 51 taken at a position similar to that shown in FIG. 134. Again, the superior spring element 47 has a gently curved convex shape that can better accommodate the shape of a wearer's heel. However, the inferior spring element 50 has a cantilever shape including a concavity 76 in the middle portion 105. The middle portion 105 of the inferior spring element 50 is generally planar and can lie flat against a portion of the superior spring element 47 when the two components are affixed together. However, a portion of the medial side 35, lateral side 36, and posterior side 34 of the inferior spring element 50 descends from the middle portion 105 to form a curved cantilever shape. Further, the inferior spring element 50 is curved slightly upwards at the edges about the medial side 35, lateral side 36, and posterior side 34. The possible introduction of curvature at the edges of an inferior spring element 50 can also be used to effect the exhibited flexural and torsional stiffness of the component, as desired. As shown, an outsole 43 can be affixed to the curved edge portions of the inferior spring element 50.

[0827] FIG. 137 is a side view of a spring element 51 consisting of a superior spring element 47 including toe spring in the forefoot area 58 and an inferior spring element 50 including a compound curved shape forming a concavity 76 in the midfoot area 67.

[0828] FIG. 138 is a side view of a spring element 51 consisting of a superior spring element 47 that is relatively flat in the forefoot area 58 and an inferior spring element 50 including a compound curved shape forming a concavity 76 in the midfoot area 67.

[0829] FIG. 139 is a side view of a spring element 51 having a flexural axis 59 in the forefoot area 58 consisting of a superior spring element 47 including toe spring and an inferior spring element 50 including a relatively flat shape.

[0830] FIG. 140 is a side view of a spring element 51 having a flexural axis 59 in the forefoot area 58 consisting of a superior spring element 47 having a relatively flat shape and also an inferior spring element 50 including a relatively flat shape.

[0831] FIG. 141 is a side view of a spring element 51 having a flexural axis 59 in the midfoot area 67 consisting of a superior spring element 47 made in continuity with an inferior spring element 50 forming an elliptical shape on the posterior side 34.

[0832] FIG. 142 is a side view of a spring element 51 having a flexural axis 59 in the midfoot area 67 consisting of a superior spring element 47 formed in continuity with an inferior spring element 50 forming an upwardly rounded shape on the posterior side 34.

[0833] FIG. 143 is a side view of a spring element 51 having a flexural axis 59 in the midfoot area 67 consisting of a superior spring element 47 formed in continuity with an inferior spring element 50 forming a downwardly rounded shape on the posterior side 34.

[0834] FIG. 144 is a side view of a spring element 51 having a flexural axis 59 and a concavity 76 in the midfoot area 67 consisting of a superior spring element 47 formed in continuity with an inferior spring element 50 forming an elliptical shape on the posterior side 34.

[0835] FIG. 145 is a side view of a spring element 51 consisting of a superior spring element 47, a posterior spacer 42, and an inferior spring element 50 having a relatively flat shape. As shown, a posterior spacer 42 can provide a substantial elevation in the rearfoot area 68.

[0836] FIG. 146 is a side view of a spring element 51 consisting of a superior spring element 47, a posterior spacer 42, and an inferior spring element 50 having an upwardly curved shape at the posterior side 34. As shown, a posterior spacer 42 can provide a substantial elevation in the rearfoot area 68.

[0837] FIG. 147 is a side view of a spring element 51 consisting of a superior spring element 47, a posterior spacer 42, and an inferior spring element 50 having a complex curved shape at the posterior side 34. As shown, a posterior spacer 42 can provide a substantial elevation in the rearfoot area 68.

[0838] FIG. 148 is a side view of a spring element 51 consisting of a superior spring element 47, a posterior spacer 42, and an inferior spring element 50 having an arcuate shape. As shown, a posterior spacer 42 can provide a substantial elevation in the rearfoot area 68.

[0839] FIG. 149 is a side view of a spring element 51 consisting of a superior spring element 47, a posterior spacer 42, and an inferior spring element 50 that is orientated downward along the posterior spacer 42, but which is relatively flat near the posterior side 34. As shown, a posterior spacer 42 can provide a substantial elevation in the rearfoot area 68.

[0840] FIG. 150 is a side view of a spring element 51 consisting of a superior spring element 47 made in continuity with an inferior spring element 50 forming an elliptical shape on the posterior side 34. As shown, the anterior portion of the inferior spring element 50 is affixed to a posterior spacer 42 which can provide substantial elevation in the rearfoot area 68. Alternately, an inferior spring element 50 can be made as a separate part, and can then be affixed to a posterior spacer 42 and/or superior spring element 47 near the anterior end of the inferior spring element 50, and also be affixed to the superior spring element 47 near the posterior end of the inferior spring element 50.

[0841] While it is generally preferred or advantageous that the inferior spring element 50 and flexural axis 59 be positioned in the midfoot area 67 or rearfoot area 68, it is possible for the inferior spring element 50 to extend into the anterior portion of the midfoot area 67 and forefoot area 58, as shown in FIGS. 151-154, and the like. FIG. 151 is a bottom plan view of a spring element 51 consisting of a superior spring element 47 and an inferior spring element 50. Line 104 indicates the approximate position of a wearer's metatarsal-phalangeal joints relative to the superior spring element 47. Again, on the medial side 35 the metatarsal-phalangeal joints are commonly found at slightly less than 70 percent of foot length and on the lateral side 36 greater than 60 percent of foot length, but yet somewhat less than on the medial side 35, that is, as measured from the posterior side 34 of an article of footwear 22. FIG. 151 illustrates the possibility of the flexural axis 59 being generally consistent with line 104.

[0842] FIG. 152 is a bottom plan view of a spring element 51 consisting of a superior spring element 47 and an inferior spring element 50. Line 104 indicates the approximate position of a wearer's metatarsal-phalangeal joints relative to the superior spring element 47. FIG. 152 illustrates the possibility of the flexural axis 59 being posterior and generally parallel to line 104.

[0843] FIG. 153 is a bottom plan view of a spring element 51 consisting of a superior spring element 47 and an inferior spring element 50. Line 104 indicates the approximate position of a wearer's metatarsal-phalangeal joints relative to the superior spring element 47. FIG. 153 illustrates the possibility of the flexural axis 59 being posterior and generally parallel to line 104 on the medial side 35, but then curved posteriorly away from line 104 on the lateral side 36.

[0844] FIG. 154 is a bottom plan view of a spring element 51 consisting of a superior spring element 47 and an inferior spring element 50. Line 104 indicates the approximate position of a wearer's metatarsal-phalangeal joints relative to the superior spring element 47. FIG. 154 illustrates the possibility of the flexural axis 59 being posterior and curved posteriorly away from line 104 on the medial side 35 and lateral side 36.

[0845] FIG. 155 is a top plan view of a spring element 51 which can consist solely of a superior spring element 47, or alternately, a superior spring element 47 can serve as a sub-component of a more complex spring element 51, such as one that could further include an inferior spring element 50. Further, a spring element 51 can extend substantially the entire length of an article of footwear 22, thus in the forefoot area 58, midfoot area 67, and rearfoot area 68, or alternately, in only a portion of the length of an article of footwear 22. In this regard, a spring element 51 can be positioned in solely the rearfoot area 68, or alternately the rearfoot area 68 and midfoot area 67, or alternately solely in the forefoot area 58, or alternately the forefoot area 58 and midfoot area 67. Also shown in FIG. 155 are three primary characteristic last shapes corresponding to the insole net, top net, or bottom net associated with a given last or configuration of an article of footwear 22. In this regard, on the medial side 35 is shown a line corresponding to straight last 108, semi-curved last 106, and curved last 107 configurations. A semi-curved last 106 shape is used in most of the drawing figures herein, but it can be readily understood that a more curved last 107 or straight last 108 configuration can be used in any or all of the embodiments. It can be readily understood that the teachings regarding possible alternate embodiments, structure, and function contained in this paragraph can also be applied to man y of the other embodiments shown in the drawing figures of this patent application, and in particular to FIGS. 155-220, but for the sake of brevity the relevant discussion contained in this paragraph will not be repeated in association with each embodiment and drawing figure.

[0846] FIG. 156 is a top plan view of a spring element 51 that includes a notch 71 on the lateral side 36 posterior of the approximate position of a wearer's metatarsal-phalangeal joints indicated by line 104. The inclusion of a notch 71 can reduce the flexural modulus or stiffness in bending exhibited along the longitudinal axis 59, but also the torsional stiffness exhibited as between the forefoot area 58, and both the midfoot area 67 and rearfoot area 68. The inclusion of a notch 71 can also create a potential or actual generally transverse line of flexion 54 as between the medial side 35 and the lateral side 36 of the spring element 51.

[0847] At higher walking or running speeds, or when jumping, it is known that individuals often impart higher forces on the medial side 35 of the forefoot 58 to greater degree than the lateral side 36, and so there can then sometimes be a need, and it can be advantageous to provide greater stiffness on the medial side 35 of the forefoot area 58. Further, given the biomechanical events associated with walking and running, it can be advantageous to reduce the torsional stiffness exhibited on the lateral side 36 of the forefoot area 58 relative to the medial side 35, as this can reduce the length of the effective lever arm formed by the spring element 51 and sole 32 of an article of footwear 22, thereby reduce the rate and magnitude of inward rotation of the foot and so enhance stability and performance. In addition, reducing the torsional stiffness exhibited on the lateral side 36 of the forefoot area 58 can increase the amount of deflection which takes place during impact and the ground support phase of the gait cycle, thus enhance perceived and actual cushioning effects. Moreover, the transition and work performed by the foot during the ground support phase can then be smoother and more economical, but also more natural or comfortable for a wearer. It can be readily understood that this description of biomechanical events and advantageous function could apply to many of the embodiments recited in the specification and shown in the drawing figures of this patent application, but for the sake of brevity the discussion contained in this paragraph will not be repeated in association with each embodiment and drawing figure.

[0848] FIG. 157 is a top plan view of a spring element 51 that includes two notches 71 on the lateral side 36, a first notch 71 posterior and a second notch 71 anterior of the approximate position of a wearer's metatarsal-phalangeal joints indicated by line 104. The inclusion of notches 71 can reduce the flexural modulus or stiffness in bending exhibited along the longitudinal axis 59, and in particular, in the area between both notches 71. Further, the inclusion of notches 71 can also reduce the torsional stiffness exhibited in the area between both notches 71, and also as between the forefoot area 58, and both the midfoot area 67 and rearfoot area 68. The inclusion of notches 71 can also create at least one potential or actual generally transverse line of flexion 54 as between the medial side 35 and the lateral side 36 of the spring element 51, but also at least one potential or actual generally longitudinal line of flexion 54 as between adjacent notches 71 located on the same side.

[0849] FIG. 158 is a top plan view of a spring element 51 that includes two notches 71 on the lateral side 36, a first notch 71 posterior and a second notch 71 anterior of the approximate position of a wearer's metatarsal-phalangeal joints indicated by line 104. Further, the spring element 51 includes one notch 71 on the medial side 35 that is generally transverse and opposing the anteriormost notch 71 on the lateral side 36.

[0850] Again, The inclusion of notches 71 can reduce the flexural modulus or stiffness in bending exhibited along the longitudinal axis 59, and in particular, in the area between both notches 71. Further, the inclusion of notches 71 can also reduce the torsional stiffness exhibited in the area between both notches 71, and also as between the forefoot area 58, and both the midfoot area 67 and rearfoot area 68. The inclusion of notches 71 can also create at least one potential or actual generally transverse line of flexion 54 as between the medial side 35 and the lateral side 36 of the spring element 51, but also at least one potential or actual generally longitudinal line of flexion 54 as between adjacent notches 71 located on the same side. It can be readily understood that this description of function could apply to many of the embodiments recited in the specification and shown in the drawing figures of this patent application, but for the sake of brevity the discussion contained in this paragraph will not be repeated in association with each embodiment and drawing figure.

[0851] FIG. 159 is a top plan view of a spring element 51 that is configured in a shape consistent with a straight last 108 and includes two notches 71 on the lateral side 36 that extend over half the distance from the lateral side 36 to the longitudinal axis 59, one being located posterior and another anterior of the approximate position of a wearer's metatarsal-phalangeal joints indicated by line 104.

[0852] FIG. 160 is a top plan view of a spring element 51 that includes two notches 71 on the lateral side 36, a first notch 71 being located posterior and a second notch 71 being located anterior of the approximate position of a wearer's metatarsal-phalangeal joints indicated by line 104, and also an opening 72 in the form of a longitudinal slit 82 located therebetween.

[0853] FIG. 161 is a top plan view of a spring element 51 that includes a notch 71 on the lateral side 36 being located posterior of the approximate position of a wearer's metatarsal-phalangeal joints indicated by line 104, and another notch 71 extending from near the anterior side 33 and forming a longitudinal slit 82.

[0854] FIG. 162 is a top plan view of a spring element 51 that includes two notches 71 on the lateral side 36, a first notch 71 being located posterior and a second notch 71 being located anterior of the approximate position of a wearer's metatarsal-phalangeal joints indicated by line 104, and an another notch 71 extended from near the anterior side 33 and forming a longitudinal slit 82.

[0855] FIG. 163 is a top plan view of a spring element 51 that includes one notch 71 on the lateral side 36 located posterior of the approximate position of a wearer's metatarsal-phalangeal joints indicated by line 104, and also an opposing notch 71 on the medial side 35.

[0856] FIG. 164 is a top plan view of a spring element 51 that includes three notches 71 on the lateral side 36, a first notch 71 being located posterior, a second notch 71 being along, and a third notch 71 being anterior of the approximate position of a wearer's metatarsal-phalangeal joints indicated by line 104, and also three opposing notches 71 on the medial side 35.

[0857] FIG. 165 is a top plan view of a spring element 51 that includes one notch 71 on the lateral side 36 located posterior of the approximate position of a wearer's metatarsal-phalangeal joints indicated by line 104, and a notch 71 extending from the anterior side 33 forming a longitudinal slit 82 thereby defining two fingers 109.1 and 109.2.

[0858] FIG. 166 is a top plan view of a spring element 51 that includes three notches 71 on the lateral side 36, a first notch 71 being located posterior, a second notch 71 being along, and a third notch 71 being located anterior of-the approximate position of a wearer's metatarsal-phalangeal joints indicated by line 104.

[0859] FIG. 167 is a top plan view of a spring element 51 that includes three notches 71 on the lateral side 36, a first notch 71 being located posterior, a second notch 71 being along, and a third notch 71 being located anterior of the approximate position of a wearer's metatarsal-phalangeal joints indicated by line 104, and a notch 71 on the medial side 35 opposing the posteriormost notch 71 on the lateral side 36.

[0860] FIG. 168 is a top plan view of a spring element 51 that includes three notches 71 on the lateral side 36, a first notch 71 being located posterior, a second notch 71 being along, and a third notch 71 being located anterior of the approximate position of a wearer's metatarsal-phalangeal joints indicated by line 104, and a notch 71 on the medial side 35 opposing the posteriormost notch 71 on the lateral side 36, and another notch 71 on the medial side 35 opposing the anteriormost notch 71 on the lateral side 36.

[0861] FIG. 168 is a top plan view of a spring element 51 that includes three notches 71 on the lateral side 36, a first notch 71 being located posterior, a second notch 71 being along, and a third notch 71 being located anterior of the approximate position of a wearer's metatarsal-phalangeal joints indicated by line 104, and a notch 71 on the medial side 35 opposing the posteriormost notch 71 on the lateral side 36, and another notch 71 on the medial side 35 opposing the anteriormost notch 71 on the lateral side 36.

[0862] FIG. 169 is a top plan view of a spring element 51 that includes three notches 71 on the lateral side 36, a first notch 71 being located posterior, a second notch 71 being along, and a third notch 71 being located anterior of the approximate position of a wearer's metatarsal-phalangeal joints indicated by line 104, and a notch 71 on the medial side 35 opposing the posteriormost notch 71 on the lateral side 36, and another notch 71 on the medial side 35 opposing the middle notch 71 on the lateral side 36.

[0863] FIG. 170 is a top plan view of a spring element 51 that includes four notches 71 on the lateral side 36, a first notch 71 being located posterior, a second notch 71 being along, and third and fourth notches 71 being located anterior of the approximate position of a wearer's metatarsal-phalangeal joints indicated by line 104, and a notch 71 on the medial side 35 opposing the posteriormost notch 71 on the lateral side 36.

[0864] FIG. 171 is a top plan view of a spring element 51 that includes four notches 71 on the lateral side 36, a first notch 71 being located posterior, a second notch 71 being located along, and a third and fourth notch 71 being located anterior of the approximate position of a wearer's metatarsal-phalangeal joints indicated by line 104, and a notch 71 on the medial side 35 opposing the posteriormost notch 71 on the lateral side 36, and another notch 71 on the medial side 35 opposing the anteriormost notch 71 on the lateral side 36.

[0865] FIG. 172 is a top plan view of a spring element 51 that includes four notches 71 on the lateral side 36, a first notch 71 being located posterior, a second notch 71 being located along, and a third and fourth notch 71 being located anterior of the approximate position of a wearer's metatarsal-phalangeal joints indicated by line 104, and a first notch 71 on the medial side 35 opposing the posteriormost notch 71 on the lateral side 36, a second notch 71 on the medial side 35 consistent with the position of line 104, and a third notch 71 on the medial side 35 opposing the anteriormost notch 71 on the lateral side 36.

[0866] FIG. 173 is a top plan view of a spring element 51 that includes four notches 71 on the lateral side 36, a first notch 71 being located posterior, a second notch 71 being located along, and a third and fourth notch 71 being located anterior of the approximate position of a wearer's metatarsal-phalangeal joints indicated by line 104, and four notches 71 on the medial side 35 opposing those on the lateral side 36.

[0867] FIG. 174 is a top plan view of a spring element 51 having the shape of a curved last 107 and a notch 71 extending from the anterior side 33 forming a longitudinal slit 82 thereby defining two fingers 109.1 and 109.2.

[0868] FIG. 175 is a top plan view of a spring element 51 having the shape of a semi-curved last 106 and a notch 71 extending from the anterior side 33 forming a longitudinal slit 82 that nearly extends to line 104 thereby defining two fingers 109.1 and 109.2.

[0869] FIG. 176 is a top plan view of a spring element 51 that includes three notches 71 on the lateral side 36, a first notch 71 located posterior, a second notch 71 located along, and third notch 71 located anterior of the approximate position of a wearer's metatarsal-phalangeal joints indicated by line 104, a notch 71 extending from the anterior side 33 forming a longitudinal slit 82 thereby defining two fingers 109.1 and 109.2, and a notch 71 on the medial side 35 opposing the anteriormost notch 71 on the lateral side 36

[0870] FIG. 177 is a top plan view of a spring element 51 that includes three notches 71 on the lateral side 36, a first notch 71 located posterior, a second notch 71 located along, and a third notch 71 located anterior of the approximate position of a wearer's metatarsal-phalangeal joints indicated by line 104, a notch 71 extending from the anterior side 33 forming a longitudinal slit 82 thereby defining two fingers 109.1 and 109.2, and two notches 71 on the medial side 35, one opposing the anteriormost and another opposing the posteriormost notches 71 on the lateral side 36.

[0871] FIG. 178 is a top plan view of a spring element 51 that includes three notches 71 on the lateral side 36, a first notch 71 located posterior, a second notch 71 located along, and a third notch 71 located anterior of the approximate position of a wearer's metatarsal-phalangeal joints indicated by line 104, a notch 71 extending from the anterior side 33 forming a longitudinal slit 82 thereby defining two fingers 109.1 and 109.2, and three notches 71 on the medial side 35 opposing those on the lateral side 36.

[0872] FIG. 179 is a top plan view of a spring element 51 that includes two notches 71 on the lateral side 36, a first notch 71 located posterior and a second notch 71 located anterior of the approximate position of a wearer's metatarsal-phalangeal joints indicated by line 104, a notch 71 extending from the anterior side 33 forming a longitudinal slit 82 thereby defining two fingers 109.1 and 109.2, and a notch 71 on the medial side 35 opposing the anteriormost notch 71 on the lateral side 36.

[0873] FIG. 180 is a top plan view of a spring element 51 that includes one notch 71 on the lateral side 36 located posterior of the approximate position of a wearer's metatarsal-phalangeal joints indicated by line 104, and two notches 71 extending from near the anterior side 33 forming two longitudinal slits 82 thereby defining three fingers 109.1, 109.2, and 109.3.

[0874] FIG. 181 is a top plan view of a spring element 51 that includes one notch 71 on the lateral side 36 located posterior of the approximate position of a wearer's metatarsal-phalangeal joints indicated by line 104, and three notches 71 extending from near the anterior side 33 forming three longitudinal slits 82 thereby defining four fingers 109.1, 109.2, 109.3, and 109.4.

[0875] FIG. 182 is a top plan view of a spring element 51 that includes three notches 71 on the lateral side 36, a first notch 71 being located posterior, a second notch 71 being located along, and a third notch 71 being located anterior of the approximate position of a wearer's metatarsal-phalangeal joints indicated by line 104, and a notch 71 on the medial side 35 opposing the anteriormost notch 71 on the lateral side 36.

[0876] FIG. 183 is a top plan view of a spring element 51 that includes four notches 71 on the lateral side 36, a first notch 71 being located posterior, a second notch 71 being located along, and third and fourth notches 71 being located anterior of the approximate position of a wearer's metatarsal-phalangeal joints indicated by line 104, and a notch 71 on the medial side 35 opposing the anteriormost notch 71 on the lateral side 36.

[0877] FIG. 184 is a top plan view of a spring element 51 that includes two notches 71 extending from near the anterior side 33 forming two longitudinal slits 82 thereby defining three fingers 109.1, 109.2, and 109.3.

[0878] FIG. 185 is a top plan view of a spring element 51 that includes three notches 71 extending from near the anterior side 33 forming three longitudinal slits 82 thereby defining four fingers 109.1, 109.2, 109.3, and 109.4.

[0879] FIG. 186 is a top plan view of a spring element 51 that includes one notch 71 on the lateral side 36 located posterior of the approximate position of a wearer's metatarsal-phalangeal joints indicated by line 104, an opposing notch 71 on the medial side 35, and two notches 71 extending from near the anterior side 33 forming two longitudinal slits 82 thereby defining three fingers 109.1, 109.2, and 109.3.

[0880] FIG. 187 is a top plan view of a spring element 51 that includes two notch on the lateral side 36, a first notch 71 being located posterior and a second notch 71 being located anterior of the approximate position of a wearer's metatarsal-phalangeal joints indicated by line 104, and two opposing notches 71 on the lateral side 36.

[0881] FIG. 188 is a top plan view of a spring element 51 that includes one notch 71 on the lateral side 36 located posterior of the approximate position of a wearer's metatarsal-phalangeal joints indicated by line 104, a notch 71 extending from the anterior side 33 forming a longitudinal slit 82 thereby defining two fingers 109.1 and 109.2, and a notch 71 on the medial side 35 opposing the notch 71 on the lateral side 36.

[0882] FIG. 189 is a top plan view of a spring element 51 that includes two notches 71 on the lateral side 36, a first notch 71 being located posterior and a second notch 71 being located anterior of the approximate position of a wearer's metatarsal-phalangeal joints indicated by line 104, a notch 71 extending from the anterior side 33 forming a longitudinal slit 82 thereby defining two fingers 109.1 and 109.2, and two notches 71 on the medial side 35 opposing the two notches 71 on the lateral side 36.

[0883] FIG. 190 is a top plan view of a spring element 51 that includes one notch 71 on the lateral side 36 located posterior of the approximate position of a wearer's metatarsal-phalangeal joints indicated by line 104, an opposing notch 71 on the medial side 35, and three notches 71 extending from near the anterior side 33 forming three longitudinal slits 82 thereby defining four fingers 109.1, 109.2, 109.3, and 109.4.

[0884] FIG. 191 is a top plan view of a spring element 51 that includes four notches 71 on the lateral side 36, a first notch 71 being located posterior, a second notch 71 being located along, and third and fourth notches 71 being located anterior of the approximate position of a wearer's metatarsal-phalangeal joints indicated by line 104, and four notches 71 on the medial side 35 opposing those on the lateral side 36, and a notch 71 extending from the anterior side 33 forming a longitudinal slit 82 thereby defining two fingers 109.1 and 109.2.

[0885] FIG. 192 is a top plan view of a spring element 51 that includes a notch 71 on the medial side 35 being located posterior of the approximate position of a wearer's metatarsal-phalangeal joints indicated by line 104, and the notch 71 then extends laterally and anteriorly towards the anterior side 33 forming a longitudinal slit 82.

[0886] FIG. 193 is a top plan view of a spring element 51 that includes a notch 71 on the lateral side 36 being located posterior of the approximate position of a wearer's metatarsal-phalangeal joints indicated by line 104, and the notch 71 then extends medially and anteriorly towards the anterior side 33 forming a longitudinal slit 82 and a relatively wide opening 82 in the forefoot area 58.

[0887] FIG. 194 is a top plan view of a spring element 51 that includes a relatively wide opening 82 in the forefoot area 58.