Adjustable dumbbell methods and apparatus

[00002] This is a divisional of U.S. patent application Ser. No. 09/747,214, filed on Dec. 21, 2000 (now U.S. Pat. No. 6,402,666, which in turn, is a continuation-in-part of U.S. patent application Ser. No. 09/290,144, filed on Apr. 13, 1999 (now U.S. Pat. No. 6,322,481), which in turn, is a continuation-in-part of U.S. patent application Ser. No. 09/020,119, filed on Feb. 6, 1998 (now U.S. Pat. No. 6,099,442).

[00003] The present invention relates to exercise equipment and more particularly, to adjustable weight dumbbells.

[00004] Exercise dumbbells are well known in the art and prevalent in the exercise equipment industry. Generally speaking, each dumbbell includes a handle and a desired number of weights or plates which are secured to opposite sides of the handle. The dumbbell is lifted up subject to gravitational force acting on the mass of the handle and attached weights. An example of an adjustable weight dumbbell is disclosed in U.S. Pat. No. 5,637,064 to Olson et al. (shows a dumbbell assembly having a plurality of weights which are stored in nested relationship to one another and selectively connected to a handle).

[00005] The present invention provides methods and apparatus which facilitate exercise involving the movement of weights subject to gravitational force. Generally speaking, the present invention allows a person to adjust weight resistance by latching a desired number of weights relative to a movable member and/or providing a desired amount of weight on opposite sides of a base member. The present invention may be applied to exercise weight stacks and/or free weight assemblies such as dumbbells and barbells.

[00006] Among other things, the present invention may be described in terms of a method of facilitating weight adjustment on an exercise dumbbell. A handle assembly is provided with a first plate, a second plate, a handle interconnected between the first plate and the second plate, a first bar projecting outward from the first plate in a first direction away from the handle, and a second bar projecting outward from the second plate in a second, opposite direction away from the handle. A first weight is configured to be secured in place between the first plate and a distal end of the first bar with the first bar occupying a downwardly opening slot in the first weight. A second weight is configured to be secured in place between the second plate and a distal end of the second bar with the second bar occupying a downwardly opening slot in the second weight. A base is provided with an upwardly facing support surface configured to support the handle assembly, and a discrete portion configured to support each said weight independent of the handle assembly. At least one said weight is selectively lifted and moved between the handle assembly and the discrete portion of the base. Many of the features and advantages of the present invention will become apparent to those skilled in the art from the more detailed description that follows.

[00037] For purposes of discussion, the present invention is described with reference to exercise dumbbells. However, those skilled in the art will recognize that one or more of the features which are disclosed herein with reference to dumbbells may be applied to barbells and/or weight stack machines, as well. Some examples of reciprocity between these two types of applications are disclosed in U.S. Pat. No. 6,033,350, which is incorporated herein by reference.

[00038] A first dumbbell constructed according to the principles of the present invention is designated as 100 and described with reference to FIGS. 1-8. The dumbbell 100 includes a parallelepiped block 110, which is preferably one or two pieces of injection molded plastic. A central opening 112, bounded by opposing end walls 111, is provided in the block 110 to receive and accommodate a person's hand. A cylindrical handle 120 is disposed within the opening 112 and extends perpendicularly between the end walls 111. The handle 120 has an outer diameter of about one inch and is sized and configured to be grasped.

[00039] Eight slots 114 are provided in the block 110 to receive and accommodate weights 140a and 140b. Each slot 114 is sized and configured to receive up to five one-pound weights 140a or one five-pound weight 140b. In other words, up to forty pounds of weights 140a and 140b may be inserted into the block 110.

[00040] FIG. 6 shows an end view of one of the weights 140a. The weight 140a is a twelve gauge steel plate approximately six inches wide and six inches high (the weights 140b present the same end view and are five times as thick). A notch 146 is provided in the weight 140a to accommodate a latch or selector rod 160, as further explained below. The sidewalls of the notch 146 may be made outwardly divergent in order to facilitate insertion of the latch 160 into the notch 146.

[00041] FIG. 3 shows an end view of the block 110. A longitudinal notch 116 is provided in the block 110 to align with the notch 146 in the weight 140a and likewise accommodate the latch 160. This notch may be provided with outwardly divergent sidewalls, as well. A transverse notch 117 is provided in the block 110 to facilitate operation of the latch 160 as further explained below.

[00042] As indicated by the arrows in FIG. 3, the latch 160 is movable in the direction X relative to the block 110. As shown in FIG. 7, the latch is movable (in the direction X) to a position outside the confines or planform of the block 110. When the latch 160 occupies the “open” position shown in FIG. 7, the weight 140a is freely movable in the direction Y (shown in FIG. 5) relative to the block 110. FIG. 5 shows the relative positions of the weights 140a and 140b and the block 110 when the notches 116 and 146 are aligned to receive the latch 160. When the weights 140a and 140b are latched in place, the longitudinal axis of the handle 120 is generally aligned with the inertia centers of the weights 140a and 140b.

[00043] When the latch 160 occupies the “closed” position shown in FIG. 5, the weight 140a is latched against movement relative to the block 110 (in the direction Y or otherwise). In particular, the relatively longer walls of the slot 114 prevent the weight 140a from moving axially relative to the handle 120; and the relatively shorter walls of the slot 114 prevent the weight 140a from moving in the radial direction X; and the latch 160 (along with the opposite, relatively shorter wall of the slot 114) prevents the weight 140a from moving in the radial direction Y.

[00044] FIG. 7 shows how the latch 160 is movably connected to the block 110. A cylindrical opening or bore 161 is provided in each of the end walls 111 of the block 110 to receive a respective shaft 164. Each shaft 164 has a first end connected to the latch 160 and a second, opposite end having a relatively large diameter head 165. A helical spring 166 is mounted on each shaft 164 and compressed between the head 165 and a plug 162 which inserts into the proximate end of the opening 161 to secure the spring 166 and the head 165 therein. The spring 166 biases the latch 160 toward the notches 116 and 146 and the closed position shown in FIG. 5. The spring 166 acts in the direction X, perpendicular to the direction Y, and thus, is not subject to gravitational force acting on the weight 140a.

[00045] The notch 117 enables a person to “reach behind” the latch 160 and pull it toward the open position shown in FIG. 7. The relative sizes of the weights 140a and 140b and the block 110 are such that the block 110 may be pushed downward relative to the weights 140a and 140b to temporarily secure the latch 160 in the open position (bearing against the outside edges of the weights 140a and 140b). Subsequent upward movement of the block 110 relative to the weights 140a and 140b will cause the latch 160 to snap into the notches 116 and 146.

[00046] FIG. 8 shows a base or housing 190 which is sized and configured to receive two of the dumbbells 100 and up to eighty pounds of weights 140a and 140b. A first compartment 191 is provided for one dumbbell 100, and a second compartment 192 is provided for another dumbbell 100. Each of four compartments 194 is sized and configured to receive and accommodate twenty pounds of weights 140a and 140b. In a preferred embodiment, twenty one-pound weights 140a and twelve five-pound weights 140b are provided together with two blocks 110 and one base 190. Assuming that each block 110 weighs three pounds, this arrangement provides two dumbbells 100 which may be adjusted between three and forty-three pounds in one pound increments.

[00047] Among other things, those skilled in the art will recognize that the dumbbell 100 and/or the base 190 provide convenient and reliable means for holding the weights in place prior to selection; changing the amount of weight engaged for exercise motion; supporting the weights during exercise motion; and/or returning the weights to their proper location at the conclusion of exercise motion.

[00048] Those skilled in the art will further recognize a variety of modifications to the foregoing embodiment which fall within the scope of the present invention. For purposes of illustration, some of the many possible variations are embodied on a dumbbell designated as 200 and described with reference to FIGS. 9-13. This second dumbbell 200 similarly includes a block-shaped member 210, which is preferably one or two pieces of injection molded plastic. A central opening 212 is provided in the block 210 to receive and accommodate a person's hand. The opening 212 is bounded by opposing end walls 211. A cylindrical handle 220 is disposed within the opening 212 and extends perpendicularly between the end walls 211.

[00049] Eight upwardly opening slots or compartments 214 are provided in the block 210 to receive and accommodate weights 240a and 240b. The compartments 214 are bounded by a bottom wall 219, and the handle 220 is positioned to align more with the centers of inertia of the weights 240a and 240b within the compartments 214 than with the geometric center of the end walls 211 on the block 210. The compartments are bounded by flanges 213 rather than continuous intermediate walls. One compartment 214 on each side of the block 210 is sized and configured to receive one ten-pound weight 240b, and the other three compartments 214 on each side of the block 210 are sized and configured to receive up to five one-pound weights 240a or one five-pound weight. In other words, up to fifty pounds of weights 240a and 240b may be inserted into the block 210.

[00050] The weight 240a is a twelve gauge steel plate approximately six inches wide and six inches high (the weights 240b are similar in shape but ten times as thick). Like on the first dumbbell weights 140a and 140b, a notch is provided in each weight 240a and 240b to accommodate a latch or selector rod 260, as further explained below. In addition, a hemispherical opening 245 is provided in each weight 240a and 240b to facilitate handling of the weights 240a and 240b.

[00051] FIG. 11 shows an end view of the block 210. A notch 216 is provided in the block 210 to align with the notches in the weights 240a and 240b and likewise accommodate the latch 260. A discrete notch 217 is provided in the block 210 to facilitate manipulation of the latch 260, as further explained below.

[00052] As in the case of the first embodiment 100, the latch 260 is movable in a first, horizontal direction relative to the block 210 (with reference to the upright orientations shown in FIGS. 10-13). The latch 260 is movable between an open position, outside the planform of the block 210, and a closed position, shown in FIGS. 11 and 13. When the latch 260 occupies the open position, the weights 240a and 240b are movable in a second, vertical direction relative to the block 210. FIG. 13 shows the relative positions of the weights 240a and 240b and the block 210 when the notches are aligned to receive the latch 260. When the latch 260 occupies the closed position, the weights 240a and 240b are latched against movement relative to the block 110 (in any direction).

[00053] The latch 260 includes a middle portion which selectively occupies the notch 216, opposite outside portions which extend perpendicularly away from the middle portion and overlie opposite outside walls 218 of the block 210, and opposite distal portions which extend perpendicularly away from respective outside portions and toward the bottom wall 219. The outside portions are slidably mounted to respective outside walls 218 by means of sleeve members 267, and the distal portions snap into and out of engagement with resilient clip members 268. The clip members 268 releasably retain the latch 260 in the closed position inside the notch 116. The arrangement is such that the clip members 268 are not subject to gravitational force acting on the weights 240a and 240b. Like on the first dumbbell 100, the notch 217 enables a person to “reach behind” the latch 260 and pull it toward the open position.

[00054] A base or housing similar to that shown in FIG. 8 may be provided for two of the dumbbells 200 and up to one hundred pounds of weights. In a preferred embodiment, the base is sized and configured to receive and accommodate twenty one-pound weights 240a, eight five-pound weights (not shown), and four ten-pound weights 240b. Assuming that each block 210 weighs three pounds, this arrangement provides two dumbbells 200 which may be adjusted between three and fifty-three pounds in one pound increments.

[00055] Among other things, those skilled in the art will recognize that the second embodiment provides convenient and reliable means for enclosing the weights during exercise motion, as well as holding the weights in place prior to selection; changing the amount of weight engaged for exercise motion; supporting the weights during exercise motion; and/or returning the weights to their proper location at the conclusion of exercise motion.

[00056] Additional variations of the present invention are embodied on a dumbbell designated as 300 and described with reference to FIGS. 14-21. As shown in FIG. 16, this third dumbbell 300 has a cylindrical bar 320 which is approximately sixteen inches long and one inch in diameter. Rigid plates 311 are secured to the bar 320 at locations about six inches apart from one another, thereby defining an intermediate handle portion and opposite distal portions.

[00057] Three weight supports or housings 330 are mounted on each of the distal portions of the bar 320, adjacent a respective plate 311. As shown in FIGS. 17-19, each housing 330 has a rectangular end wall 331 and opposite side walls or shoulders 337. A hole 332 is formed through the end wall 331 to receive the bar 320, and each housing 330 is mounted on the bar 320 in such a manner that the end wall 331 is relatively distant from the plates 311. The plates 311 have the same rectangular shape as the end walls 331.

[00058] The innermost housing 330 on each side of the bar 320 cooperates with a respective plate 311 to define a weight compartment or slot. The intermediate housing 330 on each side of the bar 320 cooperates with the end wall 331 of a respective innermost housing 330 to likewise define a weight compartment or slot. Similarly, the outermost housing 330 on each side of the bar 320 cooperates with the end wall 331 of a respective intermediate housing 330 to likewise define a weight compartment or slot. Posts 338 on the housings 330 cooperate with holes 339 in adjacent housings 330 and the plates 311 to maintain alignment and facilitate interconnection of the parts. A fastener 302 is fixedly mounted on each end of the bar 320 to prevent axial movement of the housings 330 relative to the bar 320.

[00059] Leaf springs 334 are provided on opposite sides of the housing 330. The leaf springs 334 may be described as inwardly convex and/or as having inwardly projecting portions 335 which are generally arcuate in shape. As further explained below, the leaf springs 334 perform both the latching and biasing functions which required discrete components on the previous embodiments. Openings 336 are provided in the end wall 331 to facilitate injection molding process which makes the housings 330.

[00060] Each compartment on the dumbbell 300 is sized and configured to receive up to five pounds of weight. For example, each compartment may support five one-pound weights 340a, or two two-pound weights 340b and one one-pound weight 340a, or one five-pound weight 340c. In other words, up to thirty pounds of weights 340a-340c may be inserted into the compartments on the dumbbell 300. A base similar to that shown in FIG. 8 may be provided for two of the dumbbells 300 and up to sixty pounds of weights. In a preferred embodiment, the base is sized and configured to receive and accommodate four one-pound weights 340a, eight two-pound weights 340b, and eight five-pound weights 340c. Assuming that each “empty” dumbbell 300 weighs three pounds, this arrangement provides two dumbbells 300 which may be adjusted between three and thirty-three pounds in one pound increments.

[00061] The weight 340a is a twelve gauge steel plate approximately six inches wide and seven inches high (the weights 340b are similar in shape but twice as thick, and the weights 340c are similar in shape but five times as thick). As shown in FIG. 20, a relatively deep, central notch 342 is provided in each weight 340a-340c to accommodate or provide clearance for the bar 320. Relatively shallow, arcuate notches 345 are provided in opposite sides of each weight 340a-340c to interact with the arcuate portions 335 of the leaf springs 334. In particular, as the weight 340a is inserted into a compartment, the peripheral edges of the weight 340a encounter the opposing leaf springs 334 and force the latter away from one another. When the arcuate portions 335 of the leaf springs 334 encounter the notches 345, the former snap toward one another and into the latter to bias the weight 340a against further movement relative to the housing 330.

[00062] The weights 340a-340c may be removed from the compartments by pushing the assembly downward against a floor surface. Under such circumstances, the weights 340a-340c press against the floor and thus, are subjected to an upward force equal in magnitude to the downward force. When the force is sufficient to overcome the biasing effect of the leaf springs 334, the arcuate portions 335 deflect away from one another and out of the notches 345. Once the arcuate portions 335 are bearing against the linear edges of the weights 340a-340c, the leaf springs 334 offer little resistance to removal of the weights 340a-340c.

[00063] An alternative method of removing the weights 340a-340c from the compartments may be described with reference to an optional opening 348 shown in the weight 340a in FIG. 20 and an optional tool 380 shown in FIG. 21. The tool 380 has a first distal portion 384 sized and configured for grasping, an intermediate portion or offset 386, and a second distal portion 388 sized and configured to insert into the opening 348 in the weight 340a. The tool 380 essentially allows a user to “grab” any of the weights 340a-340c and exert a sufficiently large pulling force to extract same from a weight housing 330.

[00064] Among other things, those skilled in the art will recognize that the dumbbell 300 provides convenient and reliable means for holding the weights in place prior to selection; changing the amount of weight engaged for exercise motion; supporting the weights during exercise motion; and/or returning the weights to their proper location at the conclusion of exercise motion.

[00065] Still more variations of the present invention are embodied on a dumbbell designated as 400 and described with reference to FIGS. 22-29. This fourth dumbbell 400 generally includes a handle assembly 410, a plurality of weights 440a-440h which are selectively connected to the handle assembly 410, and a base 490 which supports any of the weights 440a-440h that are not connected to the handle assembly 410.

[00066] The handle assembly 410 includes first and second plates 411 which are oval in shape. The plates 411 are rigidly secured to a cylindrical bar 420 at discrete locations spaced about six inches apart from one another. The bar 420 has an outside diameter of approximately one inch and is approximately sixteen inches long. The plates 411 cooperate with the bar 420 to define an intermediate bar portion which is sized and configured for grasping, as well as opposite distal ends of the bar 420. A rod 418 is rigidly secured between the plates 411 for reasons explained below.

[00067] A latch 430 is movably connected to the plates 411. The latch 430 may be described as equal in length to the bar 420 and extending parallel thereto. Optional end plates, similar in size and shape to the plates 411, for example, may be secured to the opposite, distal ends of the bar 420 to eliminate any perceived or potential hazard posed by protruding ends. The latch 430 moves within generally L-shaped slots 413 in the plates 411 (primarily in the radial direction designated as Y in FIG. 24). The latch 430 is movable between a “closed” position, shown in FIGS. 22-23, and an “open” position, shown in FIGS. 24-25, as more fully explained below.

[00068] The handle assembly 410 further includes a means for locking the latch 430 in either position relative to the plates 411. In particular, a relatively long tube 432 is movably mounted on the latch 430 between the plates 411. One end of the tube 432 has a relatively larger inside diameter which is bounded axially by a shoulder or rim 434. A relatively smaller tubular member 436 is mounted on the latch 430 proximate the larger diameter end of the long tube 432. A helical spring 438 is disposed within the larger diameter end of the tube 432 and compressed between the member 436 and the rim 434. The spring 438 biases the tube 432 away from the member 436.

[00069] A peg 439 projects from an opposite end of the tube 432 and parallel to the latch 430. As shown in FIG. 23, the peg 439 inserts into a first, radially inward hole in the plate 411 to secure or lock the latch 430 in the closed position. As shown in FIG. 25, the peg 439 inserts into a second, radially outward hole in the plate 411 to secure or lock the latch 430 in the open position. Movement of the tube 432 against the force of the spring 438 and toward the member 436 unlocks the latch 430 and allows it to be moved between the open position and the closed position. In other words, the latch 430 moves in a first, radial direction Y between a closed position and an open position, and the tube 432 moves in a second, axial direction X to lock and unlock the latch 430.

[00070] Each of the weights 440a-440h includes identical first and second plates 444, and a respective connector rod 446a-446h rigidly interconnected therebetween. Each plate 444 may be described as disc-shaped and includes a first, relatively large notch 442 to receive and accommodate the handle bar 420, and a second, generally L-shaped notch 443 which coincides in size and shape with a portion of the slots 413 in the plates 411.

[00071] The rod 446a is relatively short, and the weight 440a is disposed between the plates 444 on the other weights 440b-440h. The rod 446h is relatively long, and the plates 444 on the weight 440h are disposed outside the other weights 440a-440g. The rods 446b-446g and the plates 444 on the weights 440b-440g fall in between these two extremes.

[00072] The weights 440a-440h are supported by a base 490 when not carried away on the handle assembly 410. The base 490 has a flat bottom surface 492 and an arcuate top surface 494. The top surface 494 coincides with the lower periphery of the plates 411 and 444 and supports same in cup-like fashion. The base 490 has opposing side walls or surfaces 496 and 498 which extend in convergent fashion from opposite edges of the bottom surface 492 to opposite edges of the top surface 494. The side walls 496 and 498 cooperate with the rods 446h and 418, respectively, to maintain the weights 440a-440h and the handle assembly 410 in relative alignment. In particular, when the rods 446h and 418 abut respective side walls 496 and 498, the slots 413 in the plates 411 are disposed within the confines of the notches 442 in the plates 444 on the weight 440h. The same is true for each of the other weights 440a-440g having a respective rod 446a-446g rotated as far as possible toward the side wall 496.

[00073] A peg or stop 416 is provided on each of the plates 411 to facilitate alignment of the notches 443 relative to the slots 413. The pegs 416 project toward one another from respective plates 411 at a radial distance from the bar 420 equal to the radial distance between the rods 440a-440h and the bar 420. As a result, the rod 446a encounters the pegs 416 as the weight 440a is rotated relative to the handle assembly 410 and away from the surface 496 on the base 490. When the rod 446a abuts the pegs 416, the notches 443 in the plates 444 on the weight 440a align with the slots 413 in the plates 411, thereby allowing the latch 430 to occupy the radially inward ends of the notches 443, as well as the radially inward ends of the slots 413.

[00074] The present invention may also be described in terms of various methods. To illustrate this point, operation of the foregoing dumbbell 400 will be described with reference to methods of providing adjustable resistance to exercise. One such method may be described in terms of the steps of providing a base 490 sized and configured to support a plurality of weights 440a-440h in either of two positions; providing a handle assembly 410 with a handle bar 420 and a movable latch 430; selectively moving a desired number of the weights 440a-440b to an “engageable” position relative to the base 490; and moving the latch 430 into engagement with the weights 440a-440h occupying the “engageable” position. A further step may involve providing a biasing force and/or a structural interconnection which encourages the latch 430 and the weights 440a-440h to remain interengaged.

[00075] Various stages of the foregoing method are shown in the Figures. For example, in FIGS. 22-23, the latch 430 occupies the closed position relative to the plates 411 and is locked in that position by the peg 439. In FIG. 24, the latch 430 is locked in the open position, and the weights 440a-440h are free to rotate relative to the handle assembly 410 and/or the base 490. In FIGS. 25-26, the first two weights 440a-440b are shown rotated toward the pegs 416 until their notches 443 align with the slots 413. In FIG. 27, the latch 430 again occupies the closed position and is locked in that position by the peg 439. In FIGS. 28-29, the handle assembly 410 and weights 440a-440b are moved away from the base 490 and the remaining “unselected” weights 440c-440h.

[00076] With reference to the dumbbell 400, further method steps may include, for example, maintaining each of the plates 444 a fixed distance from the handle assembly 410 and/or adjacent plates 411 and 444. In this regard, spacers may be provided on the handle assembly 410 and/or on the plates 444 themselves. Methods and/or method steps may also be described with reference to more than one of the embodiments described above. For example, the present invention discloses a method of providing adjustable resistance to exercise involving the steps of disposing weights on opposite sides of a handle; supporting a desired number of weights against movement in a first direction relative to the handle; and applying a biasing force in a second, orthogonal direction to maintain the support for the weights. Those skilled in the art will also recognize other, non-disclosed structures which may be used to implement any of the methods described above or suggested by the foregoing embodiments. For example, a detent arrangement may be used to perform the “maintaining” step.

[00077] Yet another possible variation of the present invention is to arrange a plurality of loose weight plates in a row; move the desired number of plates upward relative to the remainder so that holes through the displaced plates align with holes in plates on a handle assembly; and insert a rod through the aligned holes to connect the displaced plates to the handle assembly. Still another possible variation is to use clips to connect multiple weight plates or weight housings to build weight combinations or modules which, in turn, may be selectively connected to a handle assembly or within compartments on a handle assembly.

[00078] Recognizing that aspects of various methods and/or embodiments of the present invention may be mixed and matched in numerous ways to arrive at still more variations of the present invention, and that this disclosure is likely to lead those skilled in the art to derive additional variations, the scope of the present invention is to be limited only to the extent of the following claims.