Patent Publication Number: US-6666800-B2

Title: Methods and apparatus for adjusting resistance to exercise

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This is a continuation-in-part of U.S. patent application Ser. No. 09/695,668, filed on Oct. 24, 2000, which in turn, discloses subject matter entitled to the filing date of U.S. Provisional No. 60/162,291, filed on Oct. 28, 1999. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to exercise equipment and more particularly, to exercise equipment that uses a variable number of weights to resist exercise motion. 
     BACKGROUND OF THE INVENTION 
     Exercise weight stacks are known in the art. Generally speaking, weight plates are arranged in a stack and movably mounted on at least one guide rod. A selector rod is connected to a desired number of weight plates by a pin (or other suitable means known in the art). The selector rod and any selected weight plates are connected to a force receiving member by a cable (or other suitable means known in the art) which pulls the weight plates upward in response to exercise movement. 
     Although exercise weight stacks are prevalent in the exercise industry, they nonetheless suffer from certain shortcomings. For example, in order to provide a large amount of weight at a reasonable cost and within a reasonable amount of space, equipment manufacturers use a small number of relatively heavy weight plates. As a result, the amount of weight being lifted cannot be adjusted in small increments. On the other hand, a relatively large number of lighter weight plates may be used in order to provide smaller increments in weight adjustment, but the resulting equipment would be relatively more expensive and/or bulky. 
     Attempts have been made to address the issue of incremental weight adjustments. One such approach involves the provision of a loose half-weight (weighing one-half as much as a weight plate in the stack) that is selectively movable onto the top plate at the discretion of a user. This particular arrangement is not well suited for institutional environments because the half-weight may be lost, stolen, or misused. Another prior art approach involves the provision of a half-weight or other fractional weight(s) that is/are selectively movable from a peg on the frame onto an aligned peg on the top plate of the stack. This approach not only fails to overcome the possibility of losing the half-weight, but it creates a balance problem during movement of the selected weights, and it also increases the potential for injury due to the proximity of the two pegs and their movement relative to one another. Yet another prior art approach involves the provision of a second, smaller weight stack comprising weight plates which weigh a fraction of the weight plates in the primary stack. Unfortunately, this approach adds significantly to both the cost and the size of the equipment. 
     Yet another prior art weight stack machine with supplemental or secondary weights is disclosed in French Patent No. 2,613,237 to Louvet. The Louvet machine includes a stack of primary weight plates movable along a guide rod in response to exercise movement, and a stack of secondary weights movable along the guide rod and selectively stored above the stack of primary weight plates. The secondary weights are supported by gates which are rotatably mounted on rigid frame members, and which have pegs that rotate into engagement with holes in the frame members. Each of the nine secondary weights has a mass equal to one-tenth the mass of one of the primary weight plates. One disadvantage of the Louvet machine is that nothing prevents a user from releasing a secondary weight without grasping the weight. As a result, the secondary weight may be free to drop downward onto the top plate in the primary weight stack, thereby increasing the likelihood of personal injury and/or damage to the machine. Also, each of the secondary weights is not separately supported by a respective gate. As a result, the entire stack of secondary weights may be released at one time, with or without a user holding onto any of the weights. 
     Still other prior art approaches are disclosed in Soviet Union Patent No. 1347-948-A and Japan Patent No. 10-118222. Each of these patents discloses first and second secondary weights which are movably mounted on discrete guide rods located outside the planform of the primary weight stack. The secondary weights in the Soviet patent are pivotally mounted on respective, dedicated guide rods for movement into respective positions overlying the top plate in the primary weight stack. The secondary weights in the Japan patent are releasably secured to the top plate by a separate selector pin. A shortcoming common to both of these approaches is the need for separate guide rods for the secondary weights, and/or the imposition of non-aligned weight on the primary weight stack. In other words, despite all of the efforts discussed above, room for better solutions and/or improvements still exists. 
     A prior art weight stack machine having both a primary weight stack and counter-weights is disclosed in U.S. Pat. No. 4,765,611 to MacMillan (cited during prosecution of a parent application). The MacMillan patent discloses two different embodiments that use counter-weights to impose a first magnitude of gravitational force during the power stroke portion of an exercise, and that release the counter-weights to impose a relatively greater, second level of gravitational force during the return stroke portion of the exercise. One MacMillan machine places a desired number of primary weights on a first end of a lever, and intermittently links a desired number of counter-weights to an opposite, second end of the lever. The other MacMillan machine places a desired number of primary weights on a first end of a cable, and intermittently links a desired number of counter-weights to an opposite second end of the cable. These approaches are not specifically directed toward the concept of fractional adjustments to resistance, and even if they were, room for improvement would remain. 
     SUMMARY OF THE INVENTION 
     Generally speaking, the present invention relates to exercise methods and apparatus involving a stack of primary weight plates movably mounted relative to a frame, and at least one secondary weight which is selectively activated to incrementally reduce the weight of the selected primary weight plates. A connector is selectively interconnected between the secondary weight and the top plate in the primary weight stack. More specifically, the connector includes a first portion which is connected to the top plate, a second portion which selectively supports the secondary weight, and a third portion which is intermediate the first portion and the second portion, and which is connected to the machine frame. As a result of this arrangement, the secondary weight acts as a counter-weight vis-a-vis the top plate when the former is supported by the second portion of the connector. The connector is preferably a cable, and the third, intermediate portion of the connector is preferably routed about pulleys on the frame. Moreover, the frame is preferably provided with structure to guide the secondary weight in a direction opposite that of the top plate. 
     On some embodiments of the present invention, the secondary weight is selectively movable between an active position, supported by the connector, and an inactive position, supported by the frame. On other embodiments of the present invention, a fastener or latch is selectively movable between an active position, interconnected between the frame and the secondary weight, and an inactive position, connected at most to only of the frame and the secondary weight. In any event, the secondary weight(s) may be configured for engagement and disengagement in various ways, including rotational movement, translational movement, or a combination thereof. Many of the features, variations, and advantages of the present invention will become apparent from the more detailed description that follows. 
    
    
     BRIEF DESCRIPTION OF THE FIGURES OF THE DRAWING 
     FIG. 1 is a partially fragmented, front view of an exercise apparatus constructed according to the principles of the present invention; 
     FIG. 2 is a sectioned side view of a secondary weight on the exercise apparatus of FIG. 1; 
     FIG. 3 is a partially sectioned and fragmented, front view of a secondary weight assembly on the exercise apparatus of FIG. 1, with optional knobs shown on the secondary weights; 
     FIG. 4 is a partially fragmented, side view of the secondary weight assembly of FIG. 3; 
     FIG. 5 is a partially sectioned top view of the secondary weight assembly of FIG. 3; 
     FIG. 6 is a partially sectioned fragmented, front view of the secondary weight assembly of FIG. 3, with one of the secondary weights rotated out of engagement with the secondary weight holder (and without the optional knobs); 
     FIG. 7 is a partially fragmented, side view of the secondary weight assembly of FIG. 6; 
     FIG. 8 is a partially sectioned fragmented, front view of the secondary weight assembly of FIG. 6, with all of the secondary weights rotated out of engagement with the secondary weight holder; 
     FIG. 9 is a partially fragmented, side view of the secondary weight assembly of FIG. 8; 
     FIG. 10 is a front view of another secondary weight assembly constructed according to the principles of the present invention; 
     FIG. 11 is a side view of the secondary weight assembly of FIG. 10; 
     FIG. 12 is a partially sectioned front view of the secondary weight assembly of FIG. 10 (showing the assembly with its selector pin removed); 
     FIG. 13 is a partially sectioned front view of the secondary weight assembly of FIG. 10 (showing the assembly with its selector pin moved to an active position); 
     FIG. 14 is a partially sectioned front view of the secondary weight assembly of FIG. 10 (showing the assembly with its selector pin moved to an inactive position); 
     FIG. 15 is a partially sectioned front view of yet another secondary weight assembly constructed according to the principles of the present invention; 
     FIG. 16 is a partially sectioned bottom view of the secondary weight assembly of FIG. 15 (showing the assembly with its selector pin in an inactive position); 
     FIG. 17 is a partially sectioned bottom view of the secondary weight assembly of FIG. 15 (showing the assembly with its selector pin in an intermediate position); and 
     FIG. 18 is a partially sectioned bottom view of the secondary weight assembly of FIG. 15 (showing the assembly with its selector pin in an active position). 
    
    
     DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT 
     The present invention provides methods and apparatus related to incremental adjustment of weight stack resistance. In a preferred application, an otherwise conventional weight stack machine is provided with at least one counter-weight that is selectively maneuverable between an inactive position, supported by the frame, and an active position, acting upon the top plate in the primary weight stack. 
     With reference to the Figures of the Drawing, wherein like numerals represent like parts and assemblies throughout the several views, FIG. 1 shows a weight stack machine  2200  that has been constructed in accordance with the principles of the present invention. The machine  2200  includes a top plate  2123  and additional, underlying weight plates  2120  which are arranged in a vertical stack and movably mounted on a frame  2110  by guide rods  2112  and  2114  (or other suitable means known in the art). Bushings  2212  and  2214  may be rigidly mounted on the top plate  2123  to encourage proper alignment of the top plate  2123  and the underlying weight plates  2120  relative to the guide rods  2112  and  2114 . A resilient bumper  2116  is preferably mounted on a lower portion of the frame  2110  to support any weight plates not in use and/or to absorb impact when the lifted weight plates are returned to a rest position. A selector rod extends through the weight stack and is connected to at least one force receiving member  2199  by a cable  2138  (or other suitable means known in the art). An intermediate portion of the cable  2138  is routed about at least one pulley  2238  on the frame  2110 . 
     A transparent shield  2202  is mounted on the frame  2110  and spans the front of the machine  2200 , effectively separating a user of the machine  2200  from the guide rods  2112  and  2114  and the weight stack. A central slot  2203  is provided in the shield  2202  to facilitate insertion of a conventional selector pin into engagement with any desired weight plate  2120  in the stack. This embodiment  2200  requires a selector pin which inserts entirely inside the shield  2202 , since the slot  2203  is limited to the height of the weight stack. However, those skilled in the art will recognize that other weight stack selection methods may be employed without departing from the scope of the present invention. 
     A central block  2223  is rigidly mounted on the top plate  2123  and axially aligned with the cable  2138 . Both the weight stack cable  2138  and a second cable  2230  are connected to the block  2223  and/or the underlying top plate  2123 . The second cable  2230  is routed about pulleys  2231  and  2232  to a secondary weight assembly  2201 . A remote end of the cable  2230  is connected to a counterweight  2240  which preferably has a mass equal to that of the central block  2223  on the top plate  2123 . As a result of this arrangement, the counterweight  2240  offsets the weight of the central block  2223  and maintains the cable  2230  taut as the top plate  2123  moves up and down relative to the frame  2110 . 
     The assembly  2201  includes an elongate housing or tube  2210  that has a longitudinal axis and is mounted on a side of the frame  2110  by bolts or other suitable fasteners. One side of the housing  2210  is bounded by square corners and bears against the frame  2110 . An opposite side of the housing  2210  is rounded and faces away from the frame  2110 . Those skilled in the art will recognize that the present invention is not limited to such an arrangement. In any event, a vertical slot  2218  extends vertically along the rounded side of the housing  2210 , to accommodate vertical travel of the weights  2250 ,  2260 , and  2270  relative to the housing  2210 . Discrete horizontal slots  2215 ,  2216 , and  2217  extend from the vertical slot  2218  toward the front of the machine  2200 , to accommodate rotation of respective weights  2250 ,  2260 , and  2270  relative to the housing  2210 . Each horizontal slot  2215 ,  2216 , and  2217  terminates with a downwardly extending notch (designated as  2219  in FIG.  7 ), to bias a respective weight  2250 ,  2260 , or  2270  to remain in place relative to the housing  2210 . 
     As shown in FIG. 5, the cross-section of the housing  2210  is configured to accommodate the counterweight  2240  and the similarly sized secondary weights  2250 ,  2260 , and  2270 . The housing  2210  is preferable made of plastic, and the weights disposed inside the housing  2210  are preferably made of stainless steel, so that the latter are slideable relative to the former with relatively little frictional resistance. Other weight guiding arrangements, including strips of low friction material or guide rods, for example, may be used without departing from the scope of the present invention. Each of the weights  2250 ,  2260 , and  2270  is preferably configured to weigh one-quarter as much as one of the weight plates  2120  in the stack. However, other quantities of mass and/or numbers of weights may be provided in the alternative. 
     FIG. 2 shows a cross-section of the lowest secondary weight  2250 , which is representative of the other secondary weights  2260  and  2270  (and may also be representative of the counterweight  2240 , depending upon manufacturing preferences). The weight  2250  may be described as a cylindrical shell having an outside diameter sized for linear movement within the housing  2210 . A central bore  2253  extends through the weight  2250  and defines an inside diameter sized to accommodate unhindered passage of the cable  2230 . A relatively larger diameter recess  2254  extends into the bottom of the weight  2250  to receive a rubber disk  2255 , which defines an inside diameter at least as large as that of the bore  2253 . If economies of scale dictate that the counterweight  2240  be configured similar to the secondary weight  2250 , then an anchor piece may be configured to fasten to the end of the cable  2230  and to occupy the recess  2254  and bore  2253  on the counterweight  2240 . 
     A shaft  2257  extends radially outward from each of the secondary weights  2250 ,  2260 , and  2270 . As suggested by FIGS. 3-5, handles  2258  (or other suitable members) may be mounted on the shafts  2257  to facilitate maneuvering of the weights  2250 ,  2260 , and  2270  relative to the housing  2210 . Each shaft  2257  is sized and configured to rest within a respective notch  2219 , move along a respective horizontal slot  2215 ,  2216 , or  2217 , and move along the common vertical slot  2218 . FIGS. 3-4 show each of the secondary weights  2250 ,  2260 , and  2270  with its shaft  2257  occupying a respective notch  2219 . Under these conditions, the secondary weights  2250 ,  2260 , and  2270  are supported by the housing  2210  (in stationary positions), and the secondary weight assembly  2201  has no effect on the “primary” weight selected by a user of the machine  2200  (recognizing that the counterweight  2240  and the block  2223  simply counterbalance one another). 
     FIGS. 6-7 show the lowest secondary weight  2250  with its shaft  2257  rotated out of its horizontal slot  2215  and into the vertical slot  2218 . As a result, the lowest secondary weight  2250  is free of the housing  2210  and supported instead by the counterweight  2240 . In this activated state, the secondary weight assembly  2201  reduces the exercise load of the primary weight stack by one-quarter of the weight of a plate  2120  in the primary weight stack. For example, if each of the weight plates  2120  weighs ten pounds, and one hundred pounds is currently secured to the selector rod, then the “activation” of the lowest secondary weight  2250  reduces the selected weight to ninety-seven and one-half pounds. 
     FIGS. 8-9 show all three secondary weights  2250 ,  2260 , and  2270  with their shafts  2257  rotated out of their respective horizontal slots  2215 ,  2216 , and  2217 , and into the vertical slot  2218 . As a result of this change, all three secondary weights  2250 ,  2260 , and  2270  are free of the housing  2210  and supported by the counterweight  2240 . In this activated state, the secondary weight assembly  2201  reduces the exercise load of the primary weight stack by three-quarters of the weight of a plate  2120  (or seven and one-half pounds in the example set forth in the foregoing paragraph). 
     The slots  2215 ,  2216 , and  2217  are configured in such a manner that all three secondary weights  2250 ,  2260 , and  2270  may be rotated together relative to the housing  2210 . In this regard, the middle horizontal slot  2216  is sufficiently tall to accommodate travel of the middle weight  2260  upward into contact with the highest weight  2270  while the weights  2260  and  2270  are in their stationary orientation. Similarly, the lowest horizontal slot  2215  is sufficiently tall to accommodate travel of the lowest weight  2250  upward into contact with the middle weight  2260  while the weights  2250  and  2260  are in their storage orientation (regardless of the vertical position of the middle weight  2260  relative to the highest weight  2270 ). In other words, a user may lift up the lowest weight  2250  until both of the weights  2260  and  2270  are supported on the lowest weight  2250 , and then the weights  2260  and  2270  will rotate together with the weight  2250  into activation (with the shafts  2257  within the vertical slot  2218 ). 
     In addition to reducing noise and/or absorbing impact, the rubber disks  2255  provide a high friction interface between adjacent weights to discourage relative rotation therebetween. Those skilled in the art will recognize that registration pegs or other suitable means may be provided in the alternative, or in addition to the disks  2255 , to maintain the activated secondary weights in alignment with both the counterweight  2240  and one another. 
     Those skilled in the art will also recognize that the secondary weight assembly  2201  may be operated in an additive mode, as opposed to a deductive mode, from the perspective of a person using the machine  2200 . For example, from the user&#39;s perspective, the secondary weights  2250 ,  2260 , and  2270  could be considered “zeroed” when activated and movable along the vertical slot  2218 , and “additive” when deactivated and supported by the housing  2210 . In this alternative arrangement, the top plate  2123  is preferably configured to provide ten pounds of resistance when all four of the weights  2240 ,  2250 ,  2260 , and  2270  are supported on the cable  2230 . When the shaft  2257  on the highest weight  2270  is rotated into the horizontal slot  2217  (a stationary position), the result is a two and one-half pound increase in the user-applied force required to lift the top plate  2123 . 
     Another embodiment of the present invention is designated as  2301  in FIGS. 10-14. Like the previous embodiment  2201 , the secondary weight assembly  2301  is suitable for use in connection with a primary weight stack. The assembly  2301  similarly includes a tubular housing or sleeve  2310  that is sized and configured to accommodate passage of a “counter-weighting” cable  2230 ′, as well as vertical travel of both an anchor weight  2340  and a secondary weight  2350 . Among other things, the assembly  2301  allows a person to latch and unlatch the secondary weight  2350  without lifting or otherwise handling the secondary weight  2350 . 
     One end of the cable  2230 ′ is preferably connected to the top plate in a weight stack, and an opposite end of the cable  2230 ′ is secured relative to the anchor weight  2340 . For example, the cable  2230 ′ may be inserted through a central opening in the anchor weight  2340  and secured to ball  2334  having a diameter greater than the opening. A recess is preferably provided in the bottom of the anchor weight  2340  to accommodate the upper half of the ball  2340 . The cable  2230 ′ is routed through an opening in the secondary weight  2350  having an inside diameter that is significantly greater than the diameter of the cable  2230 ′. To the extent that economies of scale may warrant making the weights  2340  and  2350  similar in size and shape, an insert may be provided for the opening in the anchor weight  2340  to secure the cable  2230 ′ relative thereto. 
     Forward and rearward flanges  2311  and  2313  are provided on the right side of the housing  2310 . The forward flange  2311  is provided with an opening  2312  that may be described in terms of an inverted V having a first leg that extends in front of the secondary weight  2350 , and a second leg that extends away from the secondary weight  2350  and beyond the side wall of the housing  2310 . The rearward flange  2313  is provided with a circular opening  2314  that is aligned with the vertex of the V-shaped opening  2312 . 
     A selector pin  2320  extends through both openings  2312  and  2314 . The selector pin  2320  has a forward end connected to a knob  2322 , and a rearward end connected to another knob  2324 , or any other member suitable for creating a ball joint or a sloppy pivot joint. In this regard, the diameter of the opening  2314  is greater than the diameter of the pin  2320 , and the length of the pin  2320  is greater than the depth of the housing  2310 , thereby allowing the pin  2320  to pivot in non-parallel planes. 
     In the absence of exercise activity, the force of gravity acting upon the top plate in the primary weight stack exerts an upward force on the portion of the cable  2230 ′ extending within the housing  2310 . This upward force is sufficient to support both the anchor weight  2340  resting on the ball  2334 , and the secondary weight  2350  resting on the anchor weight  2340 . An interface is defined in the area of contact between the secondary weight  2350  and the anchor weight  2340 , and the assembly  2301  is constructed so that this interface is laterally aligned with the flanges  2311  and  2313  when the cable  2230 ′ is at rest. A notch  2352  is provided in the lower right side of the secondary weight  2350 , and a similar notch  2342  is provided in the upper right side of the anchor weight  2340 . Either notch  2352  or  2342  is sufficient to define a gap between the weights  2350  and  2340 , and thereby provide clearance for operation of the selector pin  2320 . 
     When the selector pin  2320  occupies the position shown in FIG. 13, the pin  2320  blocks the path of the secondary weight  2350 . As a result, the anchor weight  2340  will move down and up by itself during exercise activity. Depending on tolerances, the secondary weight  2350  may move a small amount, with the effect of reducing the overall resistance at the very beginning of the exercise stroke (which some people may consider a beneficial feature). The force of gravity acting on the secondary weight  2350  and the pin  2320  biases the pin  2320  to remain in the position shown in FIG.  13 . Additional biasing arrangements, including a toggled or over-center spring, may also used to maintain the pin  2320  in a desired position. 
     When the selector pin  2320  is moved to the position shown in FIG. 14, the pin  2320  is outside the path of the secondary weight  2350 , and the secondary weight  2350  is free to move down and up together with the anchor weight  2340  during exercise activity. The force of gravity acting on the pin  2320  biases the pin to remain in the position shown in FIG.  14 . Indicia  2319  may be provided on the housing  2310  to indicate the effect of moving the pin  2320  between opposite ends of the V-shaped opening  2312 . On this embodiment  2301 , the secondary weight  2350  is designed to change the resistance by  5  pounds, an amount equal to one-half the weight of each plate in the primary weight stack. 
     In the event that the pin  2320  is accidentally moved to the position shown in FIG. 13 while the secondary weight  2350  is beneath its rest position, upward motion of the secondary weight  2350  will simply urge the pin  2320  upward, until the pin  2320  is no longer in the way. As shown in FIGS. 12-14, the upper right side of the secondary weight  2350  may be beveled to help perform this function. Generally speaking, it may be desirable to bevel or chamfer all of the corners and edges of the weights  2350  and  2340  to facilitate smooth travel thereof. 
     Yet another embodiment of the present invention is designated as  2401  in FIGS. 15-18. Like the previous embodiment  2301 , this secondary weight assembly  2401  is also suitable for use in connection with a primary weight stack, and it also enables a person to latch and unlatch a secondary weight  2450  without lifting or otherwise handling the secondary weight  2450 . The assembly  2401  similarly includes a tubular housing or sleeve  2410  that is sized and configured to accommodate passage of a connector cable  2230 ″, as well as vertical travel of both the secondary weight  2450  and an anchor weight  2440 . The cable  2230 ″ is preferably arranged in the same manner as the cable  2230 ′, extending downward into the housing  2410  and through an opening  2453  in the secondary weight  2450 , and connected to the anchor weight  2440  by means of a ball  2434 . 
     In the absence of exercise activity, the cable  2230 ″ and the weights  2440  and  2450  occupy the respective positions shown in FIG.  15 . Each of the weights  2440  and  2450  has a relatively larger cross-section that is octagonal, and a relative smaller cross-section that is square. The weights  2440  and  2450  are arranged so that the square portion  2454  of the secondary weight  2450  rests on the square portion  2444  of the anchor weight  2440 , thereby defining a gap between the octagonal portion of the secondary weight  2450  and the octagonal portion of the anchor weight  2440 . 
     The housing  2410  has opposing side walls with respective slots  2412  that are laterally aligned with the interface between the two inactive weights  2440  and  2450 . The slots  2412  extend perpendicular to the cable  2230 ″ on the embodiment  2401 , but they may be configured in alternative ways to achieve various results. At a location beneath the slots  2412 , an L-shaped support  2414  extends outward from the front wall of the housing  2410  and then upward. A selector pin  2420  has opposite end portions  2422  that extend toward one another and into respective slots  2412 . The pin  2420  is generally U-shaped and sufficiently large to just straddle the housing  2410 . An intermediate portion  2424  of the pin  2420  serves as both a handle for purposes of moving the pin  2420 , and a stop for purposes of limiting movement of the pin  2420 . 
     FIG. 16 shows the pin  2420  in an inactive position, with the ends  2422  of the pin  2420  in the forward ends of respective slots  2412 , and outside the planform of the secondary weight  2450  (and outside the planform of the anchor weight  2440 ). The pin  2420  is hanging downward from the slots  2412 , and the intermediate portion  2424  of the pin  2420  extends beneath the support  2414  and is resting against the front wall of the housing  2410 . The force of gravity acting on the pin  2420  biases the pin  2420  to remain in this position. When the pin  2420  occupies the position shown in FIG. 16, the secondary weight  2450  is free to move down and up together with the anchor weight  2440  during exercise activity. 
     FIG. 17 shows the pin in an intermediate position, with the handle portion  2424  of the pin  2420  pivoted upward into co-planar alignment with the slots  2412 , and outside the planform of the support  2414 . FIG. 18 shows the pin  2420  in an active position, with the ends  2422  of the pin  2420  in the rearward ends of respective slots  2412 , and beneath the octagonal portion of the secondary weight  2450 . The pin  2420  is hanging downward (to a lesser extent than in FIG.  16 ), and is resting on the support  2414  and inside the upwardly extending end of the support  2414 . The support  2414  cooperates with the force of gravity acting on the pin  2420  to maintain the pin  2420  in this position. When the pin  2420  occupies the position shown in FIG. 18, the anchor weight  2440  moves down and up by itself during exercise activity. 
     The present invention may be considered advantageous to the extent that it facilitates storage and/or handling of the weights outside the path of the primary weight stack; accommodates any desired shrouding of the machine components; does not negatively impact the balance of the top plate; does not require handling of the secondary weight; and/or does not require elaborate guides for the secondary weight (which moves in a direction opposite the primary weight stack). Among other things, the opposite, downward movement of the secondary weight renders the present invention relatively safer and easier to use. For example, any accidental release of the secondary weight causes a decrease in exercise resistance. Moreover, the present invention requires little, if any, handling of the secondary weight. 
     Those skilled in the art will also recognize that the present invention may be implemented in a variety of ways. For example, the subject invention is not limited to the operational specifics of the depicted weight selection assemblies, and other weight selection methods, including ones disclosed in U.S. Pat. No. 5,944,642 and the patents identified above in the Background of the Invention (all of which are incorporated herein by reference), may be used to selectively engage and disengage counterweight (s) vis-a-vis the cable  2230  or other connector. Also, the present invention may be implemented with a flexible connector, such as cable  2230 , or with other connector arrangements, including a pivoting lever, for example. Moreover, features and/or applications discussed with reference to particular embodiments may be mixed and matched to arrive at additional embodiments and/or methods. In other words, the foregoing description not only references specific embodiments and particular methods, but it also provides sufficient information to enable those skilled in the art to recognize additional embodiments, methods, improvements, combinations, and/or applications. In view of the foregoing, the scope of the present invention is to be limited only to the extent of the following claims.