Exercise Apparatus With an Inertia System

[0001] This application claims priority to U.S. Provisional Patent Application Ser. No. 61/337,332 filed on Feb. 2, 2010 and entitled “VARIABLE AMPLITUDE INERTIA DEVICE,” the disclosure of which is incorporated herein by reference.

[0002] The present description relates generally to an exercise apparatus having an oscillating inertia system and more particularly it relates to an exercise apparatus having an oscillating inertia system with instantaneously variable amplitude.

[0003] It can be appreciated that exercise devices have been in use for many years, and many of these devices use rotary inertia devices such as a flywheel. The flywheel is typically is used to make the exercise motion more fluid. Devices that may use flywheels include exercise bicycles, elliptic motion exercise devices, linear motion exercise devices such as cross country ski trainers, and certain pendulum exercise devices.

[0004] Exercise bicycles have been in use for many years, and many use continuously rotating flywheels to smooth the exercise motion. The flywheel is typically coupled to a crank with pedals to which the user applies force. However, the amplitude of the exercise motion is constrained by the crank system and the extension and flexion of the user's limbs is defined.

[0005] Conventional elliptic motion machines use flywheels coupled to a crank system to smooth the motion of the machine. Although the elliptic path of motion of the pedals is not circular as with the exercise bike, the path is nonetheless defined and constrained by the dimensions and configuration of the crank and linkage system.

[0006] Various embodiments of the invention are directed to devices, systems and methods relating to exercise apparatuses that utilize oscillating inertia systems having instantaneously variable amplitude. In one example, an oscillating inertia includes a rotational oscillator having inertial mass. The rotational oscillator is coupled to a limb engagement member through a coupling member. During operation, the oscillating inertia system is configured to rotate in one direction, come to a stop, rotate in the other direction, come to a stop, and so on repetitively. This oscillating rotation causes the limb engagement member of the exercise device to move through a range of motion where one extent of the range of motion is fixed and the other extent of the range of motion is variable in real time responsive to a user's exerted/applied force applied to the limb engagement member.

[0007] The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. The novel features which are believed to be characteristic of the invention, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present invention.

[0024] FIG. 1 shows an isometric view of an embodiment of an oscillating inertia system in an exercise apparatus. For visual clarity, frame 101 of the exercise apparatus is shown only in part. It is understood that the frame will provide supporting locations for one or more elements of the exercise apparatus and that the configuration of the frame is adapted for appropriate placement of various elements. The limb engagement member 103 is coupled to frame 101. Limb engagement member 103 is shown having example foot plate 105 to which the user applies force through his/her feet. However, limb engagement member 103 may have other components capable of engaging other portions or limbs of a user. As an example, handle 107 is a component that can engage the user's hand. It is understood that the location and type of coupling of limb engagement member 103 to frame 101 may be one of many known to one skilled in the art and may be adapted to achieve a desired exercise pattern. As an example, limb engagement member 103 may be pivotally coupled at one end to a frame or it may be coupled to the frame through an intervening linkage assembly, but coupling is not limited to these examples. Further, limb engagement member 103 may be of various shapes, various configurations, and may have multiple elements.

[0025] Rotational oscillator 110 is coupled to shaft 112 which may be supported by an axial rotation mechanism, such as bearings 114. In one embodiment, bearings 114 are mounted to and supported by frame 101 and together with frame 101 provide support to shaft 112. In some embodiments, rotational oscillator 110 is an approximate cardoid shape. Rotational oscillator 110 may be configured to have significant rotational inertia and also function as an inertial device by incorporating weight such as weight 130. Weight 130 may be placed on rotational oscillator 110 in an asymmetric position so that in a top dead center condition, weight 130 creates a torque to displace rotational oscillator 110 from the top dead center condition.

[0026] If there is insufficient inertia in rotational oscillator 110, additional inertia devices may be utilized in some embodiments. As an example, additional inertia/brake device 116 is mounted to shaft 112. Inertia/brake device 116 may serve dual purposes. It may be an inertia device and/or a brake device. Brakes frequently have significant rotational inertia, so a brake can perform dual functions of providing inertia and braking. In one embodiment, pulley 117 is mounted to shaft 112 and is coupled to a second inertia/brake device 120 by belt 118. Inertia/brake device 120 may be supported by bearings, not shown for visual clarity. In such cases, said bearings may be mounted to and supported by frame 101. Rotational oscillator 110 and/or inertia/brake device 116 may provide adequate inertia, but if not, second inertia/brake device 120 may be utilized to add inertia to the oscillating inertia system. Accordingly, in some embodiments, three different devices may operate as inertia devices and contribute significant inertia to the oscillating inertia system, the rotational oscillator 110, the inertia/brake device 116, and the inertia/brake device 120.

[0027] Any or all of the above-described devices may be used to add inertia to the oscillating inertia system. Those skilled in the art will understand that any moving components, such as shafts, pulleys, and bearings, have nominal inertia and nominal friction. However, such nominal inertia and nominal friction generally have only a small effect on the feel and operation of an exercise apparatus. In the disclosed embodiments, inertia devices have sufficient rotational inertia to allow smooth and satisfying operation of the exercise device, and brake devices have sufficient resistance to motion to provide meaningful workloads for the user of the exercise device.

[0028] Coupling member 122 is coupled to rotational oscillator 110 at rotational oscillator coupling location 124. In this embodiment, coupling member 122 is coupled to rotational oscillator 110 using a pin at coupling location 124. However, other ways of coupling the coupling member 122 to rotational oscillator 110 may be utilized. Alternate ways of coupling may utilize bolts, rivets, adhesives, pulley, or pin with bushing or bearing, but coupling is not limited to these examples.

[0029] Coupler 122 may be guided by guide elements 128 and 129 which contact coupler 122. Guide elements 128 and 129 may be coupled to and supported by frame 101 and may be implemented as pulley devices, static elements, etc. Coupling member 122 is functionally coupled to limb engaging member 103 at coupling location 126. In the embodiment shown in FIG. 1, coupling member may be made from any material which has sufficient strength and flexibility to be utilized in the illustrated system. For example, coupling member 122 may be implemented as a flexible element such as a belt, chain, or cable. Such flexible elements can be routed through the frame 101 with multiple guide elements 128 and 129 so that limb engagement member 103 can be placed at locations within the exercise device other than immediately below guide elements 128 and 129. Also, coupling member 122 may comprise multiple elements such as links, pivoting members, rotational members, and additional flexible elements that allow placement of limb engagement member 103 at locations within the exercise device other than immediately below guide elements 128 and 129.

[0030] In FIG. 1, as the user applies force to limb engagement member 103, force is transmitted through coupling member 122 to rotational oscillator 110. This in turn causes rotation of rotational oscillator 110, shaft 112, inertia/brake device 116, pulley 117, and inertia/brake device 120. Further, in some embodiments, the described system operates in an oscillating manner such that oscillation amplitude properties of rotational oscillator 110 are variable responsive to force applied by the user to limb engagement member 103. As such, embodiments provide significant advantages over previous devices because a user may, for example, take shorter strides or steps according to a desired exercise regime. These advantages, and structure which enables such, are shown in more detail below.

[0031] FIG. 2 shows 13 phases of rotation for rotational oscillator 110 so as to demonstrate the operation of an oscillating inertia system in accordance with an embodiment of the present invention. Each of the 13 phase drawings shows the position of the rotational oscillator and the limb engagement member at the beginning of the phase. For simplicity and visual clarity, only the basic elements of an example oscillating inertia system are shown.

[0032] The initial position of rotational oscillator 110 is shown in Phase 1. This initial position of the rotational oscillator also correlates to the position shown in FIG. 1. The rotational oscillator at the beginning of phase 1 has no initial rotational velocity. This is the first dwell point. As used herein, a dwell point is a point of no velocity. As the user applies force to limb engagement member 103, force is transmitted through coupling member 122 to rotational oscillator 110. In this embodiment, during the initial rotation, coupling member 122 contacts rotational oscillator 110 on a first surface of the coupling member. The transmitted force causes rotational acceleration of rotational oscillator 110 in a clockwise direction resulting in downward motion of limb engagement member 103. As the rotational oscillator gains rotational velocity during Phase 1, energy is added to any inertial devices which may be coupled to shaft 112.

[0033] During Phase 2 and Phase 3, the user continues to apply force to limb engagement member 103, limb engagement member continues to move downward, rotational oscillator 110 continues to accelerate in a clockwise direction, and energy is added to any inertial devices coupled to shaft 112.

[0034] During Phase 4 a transition occurs. At the beginning of Phase 4, rotational oscillator coupler location 124 is at a position where portions of coupling member 122 and limb engagement member 103 are nearly stationary. This may also be referred to as an equilibrium point. Coupling member 122 and limb engagement member 103 have moved to their furthest extents. Further, force applied by the user to limb engagement member 102 at the beginning of Phase 4 does not cause any further rotational acceleration of rotational oscillator 110. Although portions of coupling member 122 and limb engagement member 103 are nearly stationary at the beginning of phase 4, rotational oscillator 110 continues clockwise rotation driven by inertia devices. Immediately after the beginning of Phase 4, the limb engagement member 103 begins to move upward. Additionally, coupling member 122 is in contact with rotational oscillator 110 on a second surface of coupling member 122. Downward force applied to limb engagement member 103 causes deceleration of rotational oscillator 110. As the limb engagement member 103 moves upward while the user applies force downward, energy is subtracted from any inertial elements coupled to shaft 110.

[0035] During Phase 5 and Phase 6, limb engagement member 103 continues to move upward and any downward force applied by the user causes deceleration of rotational oscillator 110 and further subtraction of energy from any inertial devices coupled to shaft 112.

[0036] During Phase 7 a transition occurs. Forces applied to the limb engagement member 103 by the user and by gravity have decelerated rotational oscillator 110 to zero velocity at the beginning of phase 7. This is the second dwell point, or point of no velocity. Immediately after the beginning of phase 7, rotational oscillator 110 rotates in a counterclockwise direction, opposite that of Phases 1 through 6. As the user applies force to limb engagement member 103, force is transmitted through coupling member 122 to rotational oscillator 110. The transmitted force causes rotational acceleration of rotational oscillator 110 resulting in downward motion of limb engagement member 103. As the rotational oscillator gains rotational velocity during Phase 7, energy is added to any inertial devices which may be coupled to shaft 112.

[0037] During Phase 8 and Phase 9, the user continues to apply force to limb engagement member 103, limb engagement member continues to move downward, rotational oscillator 110 continues to accelerate, and energy is added to any inertial devices coupled to shaft 112.

[0038] During Phase 10, another transition occurs that is similar to the transition of Phase 4. At the beginning of Phase 10, rotational oscillator coupler location 124 is at a position where portions of coupler 122 and limb engagement member 103 are nearly stationary for an instant. Further, force applied by the user to limb engagement member 103 at the beginning of Phase 10 does not cause any further rotational acceleration of rotational oscillator 110. Immediately after the beginning of Phase 10, the limb engagement member 103 begins to move upward. Downward force applied to limb engagement member 103 causes deceleration of rotational oscillator 110. As the limb engagement member 103 moves upward while the user applies force downward, energy is subtracted from any inertial elements coupled to shaft 112.

[0039] During Phase 11 and Phase 12, limb engagement member 103 continues to move upward and any downward force applied by the user causes deceleration of rotational oscillator 110 and further subtraction of energy from any inertial devices coupled to shaft 112.

[0040] At the beginning of Phase 13, rotational oscillator 110 and coupling member 122 are in the same position as Phase 1. Once oscillation cycle of rotational oscillator 110 has completed, a new cycle begins repeating Phases 1 through 12. As can be seen, because of the oscillating motion provided by rotational oscillator 110, as opposed to a continuously rotating crank-type device, a user may move in a smaller amplitude of motion and maintain the same general motion pattern corresponding to the type of exercise being done by the user.

[0041] During Phases 1 though 13, limb engagement member 103 in this embodiment has completed two cycles of a continuous periodic motion, during a single oscillation period of rotational oscillator 110. Phases 1-6 represent one cycle and phases 7-13 represent a second cycle. Specifically, limb engagement member 103 has started at its highest position, moved downward to its lowest position, changed direction, moved upward to its highest position, changed direction, moved to its lowest position, changed directions and moved to its highest position. During Phases 1 through 13, rotational oscillator has started at dwell point 1, rotated to the equilibrium point, changed rotational direction, rotated back to the equilibrium point, and returned to dwell point 1 where the cycle begins again. The embodiments of FIG. 1 and FIG. 2 show the shaft 112 oriented horizontally. However, the shaft and the oscillating inertia system may be disposed in any number or orientations including, but not limited to, vertical.

[0042] FIG. 3A illustrates an embodiment which shows an example implementation where two limb engagement members and two oscillating inertia systems are utilized to engage two limbs of the user. Portions of this embodiment are shown schematically in isometric view in FIG. 4. Although many of the elements of the left side of the exercise apparatus are obscured in the side view of FIG. 3A, it is understood that the left side has the same elements as the right side and operates in the same manner. Limb engagement member 103 has first and second ends. Limb engagement member 103 is pivotally coupled near the first end to frame 101 at coupling location 106. Coupling member 122 is coupled to the second end of limb engagement member at coupling location 126. Coupling member 122 is also coupled to rotational oscillator 110 which is part of the oscillating inertia system.

[0043] During operation, the user steps onto right and left plate 105 and begins a vertical stepping motion by alternately stepping downward and upward with each foot. The downward stepping motion of the right foot applies force to limb engagement member 103 and accelerates rotational oscillator 110. An example of such acceleration and motion is illustrated with respect to Phases 1 through 3 in FIG. 2. As the user's foot and right foot plate 105 reaches the bottom of the stepping motion, the downward motion of right foot plate 105 decelerates to zero. This correlates to the beginning of Phase 4 in FIG. 2. In some embodiments, nearly the full weight of the user is supported by right foot plate 105 at this plate position. As rotational oscillator 110 continues to rotate, right foot plate 105 changes direction and begins to move upward. Because energy is being transferred from the inertial devices to foot plate 105 through coupling member 122, force is applied in a manner and direction which tends to lift the user's right foot. This lifting force exerted on the right foot signals the user to begin a transfer of weight to the left foot. The right foot plate 105 continues vertical motion as exemplified in Phase 5 and Phase 6 of FIG. 2. The weight of limb engagement member 103 and any force applied by the user to right foot plate 105 causes rotational oscillator 110 to continue to decelerate. As rotational oscillator 110 continues to decelerate, it reaches zero velocity and foot engagement member 103 comes to a stop. This correlates to the second dwell point at the beginning of Phase 7 in FIG. 2. At or near this time, the user has begun to transfer body weight from the left foot plate to the right foot plate. Right foot plate 105 once again begins downward motion and the rotational oscillator 110 accelerates. The right foot plate 103 has gone through a full cycle and the rotational oscillator 110 has gone through one half of a cycle. When right foot plate 105 goes through one more cycle, the rotational oscillator 110 will have gone through one full cycle as shown in FIG. 2. Although the embodiment of FIGS. 3A-B and 4 may be operated to simulate a climbing motion, it may also be operated to simulate a jumping motion. The user would initiate exercise by alternately extending and retracting both legs in unison. This would cause both limb engagement members to move upward and downward which in turn would cause oscillation of the rotational oscillators.

[0044] During operation of the embodiment of FIGS. 3A-B and 4, the lowest position of foot plate 103 is defined and controlled by the geometry of the exercise apparatus. However, the highest position of foot plate 103 is variable and controllable by the user. In some embodiments, this variability and control is exerted in an instantaneous manner as the user applies force to the foot plate 103. During operation, the user may instantly begin to alter forces applied to foot plate 105 so as to alter and vary the step height even though the oscillator may not have reached a particular dwell point. If the user applies greater force to the right foot plate and/or applies less force to the left foot plate during downward motion of the right foot plate, rotational oscillator 110 will have greater acceleration and supplemental inertia devices, if any, will store more energy. The greater energy stored during downward motion of the right foot plate will create force which tends to lift the right foot plate higher during upward motion. Alternately, if the user applies less force to the right foot plate and/or applies greater force to the left foot plate during downward motion of the right foot plate, rotational oscillator 110 will have less acceleration and supplemental inertia devices, if any, will store less energy. The reduced energy stored during downward motion of the right foot plate will tend to lift the right plate to a reduced height during upward motion. In this way, the user can alter the step height of the illustrated embodiment by instantaneously varying the forces applied to the foot plates. Although the new step height is not known until the step reaches the top of its upward motion, the application of forces to alter the step occurs instantaneously. Therefore, for this specification, instantaneously variable amplitude may connote that the user can apply forces instantaneously to limb engagement member 103 to alter the amplitude of motion, and not necessarily that the direction of motion instantaneously changes with the application of force.

[0045] During operation of an exercise apparatus having an oscillating inertia system, the user may prefer to have resistance to motion. In the embodiment of FIGS. 3A-B and 4, inertia/brake device 116 can be actuated to provide resistance to rotation. This actuation may be utilized to provide resistance to downward motion of the limb engagement member 103 and foot plate 105. In some embodiments, the brake can be configured to selectively apply resistance in one or both directions of motion by turning the brake on and off. Such switching may be mechanically accomplished, may be controlled via a microprocessor control circuit, or may be implemented in any other manner sufficient to provide a desired resistance. It may be desirable in some embodiments to drive an inertia/brake device unidirectionally. This can be accomplished with various mechanisms. FIG. 3B illustrates one such embodiment of an inertia/brake device 116. In FIG. 3B, shafts 112 and 205 are supported by bearings, not shown for clarity. Coupled to shaft 112 are two pulleys 194 and 195. Pulleys 194 and 195 have overrunning clutches that engage shaft 112. Each clutch freewheels in one direction of rotation but locks in the opposing direction of rotation. The clutches are configured so that when one clutch is locked, the other clutch is freewheeling, and vice versa. Pulleys 202 and 203 are coupled to and rotate with shaft 205. Inertia/brake device 208 is coupled to and rotates with shaft 205. Belt 200 wraps around the four pulleys in a serpentine manner. As rotational oscillator 110 and shaft 112 oscillate, pulleys 194 and 195 are alternately driven by overrunning clutches 196 and 197 so that only one of the two pulleys is driving shaft 112 at any time. This in turn causes belt 200 to drive pulleys 202 and 203, shaft 205, and inertia/brake device 208 unidirectionally. It is noted that while the above embodiment is implemented with belts and pulleys, the inventive concepts may be implemented in any manner, such as by utilizing belts, gears, and the like.

[0046] In embodiment of FIGS. 3A-B and 4, instantaneously variable step height and a defined lowest position of the foot plate provide significant advantages over traditional reciprocal steppers. Traditional reciprocal steppers have no lower limit of motion. Therefore, the user must consciously stop downward motion or the foot plate will strike the machine or the floor. This conscious stopping of the downward motion of the plate may be uncomfortable or unsatisfying for some users. The user perceives a more natural stepping motion when utilizing inventive aspects described herein, such as in the embodiment of FIGS. 3A-B and 4 because the user's full body weight is supported by a foot plate at its lowest position. Further, the oscillating inertia system begins to exert force which tends to naturally lift the user's foot immediately after the plate reaches its lowest position, prompting the user to transfer weight to the opposing plate.

[0047] The configuration and sizing of the rotational oscillator 110 and any possible inertia devices coupled to the rotational oscillator may be done so as to accommodate the intended user and the intended exercise pattern. For example, the designer of the exercise apparatus of some embodiments may choose an average weight, an average exercise stepping cadence, and an average step height. As the user applies full body weight at the top of a step and moves downward to the bottom of the step, the potential energy of the user at the top of the step is converted to rotational kinetic energy in rotational oscillator 110 and any inertia devices at the bottom of the step, assuming no frictional or braking resistance. The potential energy at the top of the step is proportional to step height multiplied by user body weight. The rotational kinetic energy in the inertia devices is proportional to rotational mass multiplied by rotational velocity squared. User weight, exercise cadence, step height, and rotational mass of the inertia devices are all interrelated as potential energy is converted to rotational kinetic energy and vice versa. The designer may define the potential energy at the top of the step by selecting the user body weight and the step height. In this case, the designer may select appropriate rotational oscillator 110 characteristics and inertia device rotational mass to achieve the desired exercise cadence and limb engagement member velocity profile. The rotational mass of the inertia devices can be increased by adding or redistributing mass to a radial location further from the center of rotation of the inertia device. FIG. 5 shows a rotational oscillator 110 such as is illustrated in the embodiments in FIGS. 1 and 3A-B. In order to achieve preferred rotational oscillator characteristics for a particular design use, a designer may desire to adjust the size and shape of the rotational oscillator. The rotational oscillator 110 will generally be sized so that a limb engagement member 103 moves through the specified step height. A rotational oscillator that is scaled up in size and operating through the same angular range of motion will create a larger step height. The shape of the rotational oscillator may impact the velocity characteristics of the limb engagement member 103.

[0048] As shown in FIG. 5A, torque applied to rotational oscillator 110 is proportional to the effective radius of force application Ra multiplied by force transmitted by coupling member 122. In FIG. 5B, rotational oscillator 110 has rotated to another position, and the effective radius Rb has decreased from Ra because coupling member 122 is contacting rotational oscillator 110 at a different location than in FIG. 5A. In FIG. 5C, rotational oscillator 110 has rotated to still another position, and the effective radius Rc has decreased still further. In FIG. 5A, the greater effective radius of force application results in relatively greater torque and radial acceleration of rotational oscillator 110 for a given force F than in FIGS. 5B and 5C. Further, for a given radial velocity of rotational oscillator 110 in FIG. 5A, the limb engagement member 103 falls at a faster rate than in FIGS. 5B and 5C. Therefore, the designer may select a rotational oscillator shape that generates the desired velocity characteristics of limb engagement member 103. The rotational oscillators of FIGS. 1-5 are an approximate cardoid shape. A characteristic of this shape is that as the rotational oscillator nears a dwell point and the limb engagement member is slowing to a stop, the effective radius of force application may be increasing. This greater radius of force application provides additional or supplemental torque to assist in direction change of the rotational oscillator and limb engagement members. FIGS. 6A-C show examples of various shapes and configurations of rotational oscillators. The shapes shown in FIGS. 6A-C are configured for oscillating motion and not continuous unidirectional rotation. Further, the shapes of FIGS. 6A-C are generally symmetric. However, rotational oscillators are not limited to the shapes shown and may be configured to create the desired operating characteristics of the exercise apparatus.

[0049] It may be desirable to allow the user to make adjustments to the exercise apparatus to alter the feel or function. Referring to FIG. 7, FIGS. 7A-C show a servo actuation system in accordance with one embodiment that changes the geometry of the oscillating inertia system under user control. The position of the rotational oscillator 110 is the same in all three figures. Servo motor 140 is coupled to frame 101 and is configured to move pulley displacement device 143. Such movement may be accomplished in many ways. For example, in some embodiments, pulley displacement device 143 may be moved by driving a height adjustment mechanism, such as lead screw 142. Pulley displacement device 143 comprises guide elements 128 and 129, and may be configured to engage lead screw 142. The initial position of guide elements 128 and 129 is shown in FIG. 7A. In the initial position shown in FIG. 7A, the effective radius of force application is R1. As the servo motor is actuated, guide elements 128 and 129 are moved up or down. In FIG. 7B, guide elements 128 and 129 have been moved upward by the servo actuation system and closer to rotational oscillator 110. The effective radius of force application R2 has been increased from the effective radius of force application R1 in FIG. 7A. Therefore, for a given force level at limb engagement member 103, greater torque is applied to the rotational oscillator resulting in greater rotational acceleration. In FIG. 7C, guide elements 128 and 129 have been moved downward by the servo actuation system and further from rotational oscillator 110. The effective radius of force application R3 is decreased from the effective radius of force application R1 in FIG. 7A. Therefore, for a given force level at limb engagement member 103, reduced torque is applied to the rotational oscillator resulting in reduced rotational acceleration. By moving the guide elements 128 and 129 in relation to the rotational oscillator 110, the operating characteristics of the oscillating inertia system may be changed. It is appreciated that various methods may be implemented to provide adjustment to the geometry of the disclosed exercise apparatuses. As such, the above description is not intended to be limiting.

[0050] FIG. 8 shows an example embodiment having a servo actuation system that allows the user to alter the rotational mass of the rotational oscillator 110. Servo motor 145 is coupled to rotational oscillator 110 and drives lead screw 147. Adjustable weight 149 engages lead screw 145. As the servo motor 145 is actuated, adjustable weight 149 moves closer to or further from shaft 112. As adjustable weight 149 moves further from the shaft 112, the rotational mass of rotational oscillator 110 increases. Therefore, the rate of acceleration of rotational oscillator 110 is reduced for a given level of force at the limb engagement member 103 and torque at rotational oscillator 110. As adjustable weight 149 moves closer the shaft 112, the rotational mass of rotational oscillator 110 decreases. Therefore, the rate of acceleration of rotational oscillator 110 is increased for a given level of force at the limb engagement member 103 and torque at rotational oscillator 110. By changing the rotational mass under servo control, the operating characteristics of the oscillating inertia system have been changed. Again, it is appreciated that various methods may be implemented to provide adjustable weighting to alter rotation mass of oscillator 110. As such, the above description is not intended to be limiting.

[0051] Referring to FIG. 9, FIGS. 9A-C show a schematic of an embodiment of an oscillating inertia system that utilizes spring force applied to the rotational oscillator 110. This embodiment also utilizes a coupling member 122 that comprises at least a portion that is a rigid link. Limb engagement member 103 is coupled to the frame and translates back and forth under operation. Limb engagement member 103 is coupled to rotational oscillator 110 through coupling member 122. Spring 152 is coupled to rotational oscillator 110 through spring coupler 150. As the user applies force to limb engagement member 103, force is applied to rotational oscillator 110. As rotational oscillator 110 rotates, spring 152 is extended or relaxed. The interaction of rotational oscillator 110 with spring coupler 150 is similar to the interaction of rotational oscillator 110 with coupling member 122 in FIGS. 1-8. In this manner, spring force may be used to provide additional or supplemental torque in the oscillating inertia system.

[0052] FIGS. 10A-B show an embodiment that operates similarly to the embodiment of FIG. 9. However, these embodiments utilize two springs 152a and 152b which may allow greater total spring force and/or greater spring life. This embodiment also utilizes a coupling member 122 that comprises at least a portion that is a rigid link. Limb engagement member 103 is coupled to the frame and translates back and forth under operation. Limb engagement member 103 is coupled to rotational oscillator 110 through coupling member 122. Springs 152a and 152b are coupled to rotational oscillator 110 through spring couplers 150a and 150b. Spring couplers 150a and 150b may be rigid or flexible depending on the particular design characteristics of the exercise device. Further, spring couplers 150a and 150b may function to provide additional tension/spring force to supplement the force of springs 152a and 152b. As the user applies force to limb engagement member 103, force is applied to rotational oscillator 110. As rotational oscillator 110 rotates, springs 152a and 152b are extended or relaxed. In the embodiment of FIG. 10B, the interaction of rotational oscillator 110 with spring coupler 150 is similar to the interaction of rotational oscillator 110 with coupling member 122 in FIGS. 1-8. In this manner, the extension of the springs in the embodiments of FIGS. 10A-B provides additional or supplemental torque to assist in direction change of the rotational oscillator and limb engagement members.

[0053] FIG. 11 shows an embodiment of an exercise apparatus that utilizes a compliant cross coupling system to link the right and left side members. It is anticipated that previously described embodiments, such as those described above related to FIGS. 3A-B, would have independently operating right and left oscillating inertia systems. However, it may be desirable to cross couple the right and left sides so that downward motion of one side creates an upward force on the other side and vice versa. Such application of force through the cross coupling system may prompt the user to step in alternating fashion.

[0054] As shown in the embodiment in FIG. 11, right and left limb engagement members 103 are coupled at their forward ends to compliant spring/damper units 158R and 158L. The right side spring/damper 158R is coupled to left side spring/damper 158L by coupler 160. Coupler 160 is guided and positioned by pulley 162. Spring/damper units 158R and 158L may have springs or a have a combination of springs and dampers. The spring/damper units extend as force is applied by limb engagement members 103 and coupler 160. During operation of the exercise apparatus, the user steps in reciprocating fashion so that the limb engagement member on one side rises and the limb engagement member on the other side lowers. If the user maintains perfect synchronization of the right and left sides at the maximum design step height, then spring dampers 158L and 158R do not extend. However, if the user deviates from perfect synchronization or steps at a lower step height, the spring dampers extend and provide a force at the limb engagement member 103 to prompt the user to alter his stepping pattern and improve synchronization of the right and left sides. Compliance in the cross coupling system allows the user to continue to instantaneously vary the step height. Coupler 160 may be of various configurations that cause opposing motion including, but not limited to, rigid links coupled to an oscillating rocker arm. Further, the FIG. 11 embodiment has two spring/dampers, but a single spring/damper or multiple spring/dampers may be used.

[0055] FIG. 12 shows another embodiment of an exercise apparatus with compliant cross coupling. The embodiment of FIG. 12 has right and left sides similar to the embodiment of FIGS. 3A-B and 4. The right and left sides are coupled by torsional spring/damper device 166. The right side of torsional spring/damper device 166 is coupled to right side shaft 112 and the left side of torsional spring/damper device 166 is coupled to the left side shaft 112. Torsional spring/damper device 166 may incorporate gears and/or overrunning clutches so that right side shaft 112 and left side shaft 112 rotate in opposition, i.e., where one side of torsional spring/damper device 166 rotates clockwise while the opposing side rotates counterclockwise, and vice versa. During operation, torsional spring/damper device 166 may impart rotational forces to respective rotational oscillators 110 as a user makes a stepping motion or stride.

[0056] FIG. 13A shows a side view of another embodiment which implements the inventive concepts disclosed herein. In this embodiment, an exercise apparatus utilizes an oscillating inertia system that has instantaneously variable step and/or stride height and instantaneously variable horizontal stride length. Frame 101 includes a basic supporting framework. An oscillating inertia system is coupled to one end of frame 101. Similar to the embodiment of FIG. 1, rotational oscillator 110 is coupled to shaft 112. Shaft 112 is supported by the frame through bearings, not shown. Also, coupled to shaft 112 is inertia/brake device 116. Coupling member 122 is coupled at one end to rotational oscillator 110 at 124. At its other end, coupling member 122 is coupled to limb engagement member 103 at coupling location 126. Coupling member 122 engages guide elements 128, 129, and 170.

[0057] In this illustrated embodiment, arcuate motion member 174 is pivotally coupled to frame 101 at coupling location 174. Limb engagement member 103 may also be coupled to arcuate motion member 172 at coupling location 176. Arcuate motion member 174 has an upper portion 178. Upper portion 178 may be used as a handle by the user. Arcuate motion member 178 may be straight, curved, or bent in any manner to accommodate a design preference for the apparatus. Limb engagement member 103 has foot plate 105 on which the user stands. Limb engagement member 103 may also be straight, curved, or bent in any manner to accommodate a design preference for the apparatus.

[0058] In the embodiment of FIG. 13A, coupling member 122 is a flexible element which may be a belt, a cog belt, a chain, a cable, or any flexible component able to carry tension. Although the coupling member in the embodiment of FIG. 13A is shown to be a unitary continuous flexible element, the coupling member may comprise multiple elements including, but not limited to, links, rotary spools, pivoting elements, and the like. In the embodiment shown in FIG. 13B, cross coupling is accomplished with pivoting links.

[0059] FIG. 13B depicts a top view of elements of the cross coupling system shown in FIG. 13A. Elements 180 are coupled to arcuate motion members 172. Thus, each of right and left elements 180 may move in unison with each right and left arcuate motion member 172 respectively. Connectors 182 couple right and left elements 180 to the right and left sides of rocker arm 184. Rocker arm 184 is pivotally coupled at its mid portion to frame 101 at location 186. As arcuate motion members 172 move, connectors 182 cause a rocking motion of rocker arm 184. This rocking motion causes right and left arcuate motion members 172 to move in opposition and thereby accomplish cross coupling in the fore and aft directions of the right and left pivotal linkage assemblies. Coupled to rocker arm 184 is brake device 188. Brake device 188 resists movement of rocker arm 184 and therefore resists fore and aft movement of arcuate motion member 172 and limb engagement member 103.

[0060] During operation of the embodiment shown in FIG. 13A, the user ascends the exercise device, stands on foot plates 105, and initiates a climbing motion by placing his/her weight on one of foot plates 105. As the user steps downward, force is transmitted through coupling member 122 initiating oscillation of rotational oscillator 110. As the rotational oscillator 110 continues to oscillate, foot plates 105 alternately lift and lower. This lifting and lowering motion simulates the lifting and lowering motion that a user's foot may undertake during walking, striding, jogging, and climbing. The user may instantaneously alter step or stride height by altering the vertical forces he/she applies to foot plates 105. As user's foot lowers during a stepping or striding motion, foot plate 105 comes to a stop and reverses direction as the rotational oscillator 110 oscillates. The user may simultaneously apply forward and rearward forces to move the foot plates fore and aft. The amplitude of the fore and aft motion is instantaneously variable by the user who may alter fore and aft forces applied to the foot plates instantaneously. By combining instantaneously variable step or stride height with instantaneously variable stride length, the user may achieve a wide variety of foot paths. FIG. 13C shows two possible such paths, the first in solid line, the second in dashed line. The height of each path is measured at the mid portion of each path. The height the path is controlled by the user through the oscillating inertia system, and the width of the path is controlled by the user through the application of variable fore and aft forces through the foot plates. Unlike other embodiments shown, the foot plates may not come to a complete stop during a striding motion. Instead, there may be motion in either the vertical direction and/or the horizontal direction. However, the oscillating inertia system in this embodiment affects vertical amplitude in the mid portion of the striding motion much as it does in other embodiments having vertical amplitude.

[0061] The operation of the rotational oscillator 110 provides a defined direction reversal of foot plate 105 at the bottom of each step or stride taken by the user. The variation in the vertical amplitude of step or stride height occurs at the mid portion of the step or stride while the bottom of the step or stride is defined and controlled by the oscillating inertia system and is the same from step to step. The user may instantaneously alter stride length by altering the forward and rearward force he/she applies to foot plates 105. The user may instantaneously select a nearly vertical step with little horizontal displacement, or he/she may instantaneously select a longer stride with greater horizontal displacement. When the user displaces the foot plates horizontally, the combined vertical displacement and horizontal displacement results in a closed path where the amount of horizontal and vertical displacement is controllable by the user in real-time.

[0062] Further, the systems described herein may have exercise parameters adjusted by a user. In one embodiment, an exercise apparatus may include an input device pad 300 which allows a user to select one or more factors such as weight, exercise velocity, and the like. Upon selection by a user, a control system 301 within the exercise apparatus may send control signals via control lines 302 in order to engage/disengage or alter properties of one or more portions of the apparatus, such as an inertia device 116, the operational range of rotation of rotational oscillator 110, etc., in order to conform to the user's specifications.

[0063] FIG. 14 shows a side view of another embodiment. This embodiment illustrates an example implementation of a recumbent exercise apparatus utilizing an oscillating inertia system. Frame 101 includes a basic supporting framework. An oscillating inertia system is coupled to one end of frame 101. Similar to the embodiment of FIG. 1, rotational oscillator 110 is coupled to shaft 112. Shaft 112 may be supported by the frame through bearings, not shown. Also, in this embodiment inertia/brake device 116 is coupled to shaft 112. Coupling member 122 is coupled at one end to rotational oscillator 110 at 124. At its other end, coupling member 122 is coupled to limb engagement member 103 at coupling location 126. Coupling member 122 engages guide elements 128, 129, and 170.

[0064] Limb engagement member 103 is coupled to the frame at coupling location 190 and its orientation is generally vertical. Limb engagement member 103 has foot plate 105 against which the user applies force. Limb engagement member 103 may be straight, curved, or bent in any manner to accommodate a design preference for the apparatus. In the embodiment of FIG. 14, coupling member 122 is a flexible element which may be a belt, a cog belt, a chain, a cable, or any flexible component able to carry tension. Although the coupling member in the embodiment of FIG. 14 is shown to be a unitary continuous flexible element, the coupling member may comprise multiple element including, but not limited to, links, rotary spools, and pivoting elements. Seat 192 is coupled to and supported by the frame. The seat 192 has adjustment that allows the user to position the seat 192 closer to or further from the foot engagement members 103.

[0065] During operation of the embodiment shown in FIG. 14, the user sits in seat 192 and initiates an exercise pattern by applying force to foot plates 105. As the user applies force to foot plates 105, force is transmitted through coupling member 122 initiating oscillation of rotational oscillator 110. As the rotational oscillator 110 continues to oscillate, foot plates 105 move fore and aft as the user extends and flexes his/her knee. As the knee extends, foot plate 105 comes to a stop and reverses direction as the rotational oscillator 110 oscillates. The operation of the rotational oscillator 110 provides a defined direction reversal of foot plate 105 to prevent over extension of the user's leg and knee. The amplitude of motion of foot plate 105 in the direction of the user during knee flexion is instantaneously variable as the oscillating inertia system operates. Therefore, the user may instantaneously vary the range of motion of the exercise pattern.

[0066] It is noted that adjustment mechanisms, such as those illustrated with respect to FIGS. 7-8 may also be included in other disclosed devices, such as the devices of FIGS. 12-14, to control various exercise parameters. Such implementations may vary based on desired design considerations and will be apparent to those of skill in the art reviewing the present disclosure.

[0067] It is appreciated that embodiments of the teachings disclosed herein may be used in multiple types of exercise equipment devices as shown above. Example devices may include an elliptical device, stair climber, recumbent exercise apparatus, combination devices which utilize arm motion (e.g., with recumbent/elliptic devices), upper body exercise devices, and the like.

[0068] Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present invention, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present invention. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.