Patent Publication Number: US-6338701-B1

Title: Cable and puley linkage for exercise machine

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a Continuation-In-Part of Application Ser. No. 09/365,139 filed Jul. 30, 1999, which is a Continuation of application Ser. No. 08/977,189 filed Nov. 24, 1997 now U.S. Pat. No. 5,951,444. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates generally to weight lifting exercise machines, and is particularly concerned with a cable and pulley linkage apparatus for coupling a load to various exercise stations in such a machine. 
     A typical exercise or weight machine has a support frame, a load such as a weight stack mounted on the frame, and various different exercise stations linked to the load, usually by means of a cable and pulley system consisting of a series of fixed and floating pulleys around which one or more cables extend. Such a machine is described in my U.S. Pat. No. 5,236,406, for example, the contents of which are incorporated herein by reference. 
     One problem with existing cable and pulley linkages is that a large number of pulleys is required to link a weight stack to several exercise stations, and the more pulleys you provide, the greater the space that is required. Additionally, there is a limit to the resistance ratio and the number of pulling points which can be achieved with current floating pulley arrangements. A 3 to 1 resistance ratio is the maximum which can be achieved in most current systems. 
     SUMMARY OF THE INVENTION 
     It is an objective of the present invention to provide a new and improved cable and pulley linkage system for weight lighting exercise machines. 
     According to one aspect of the present invention, a cable and pulley linkage system is provided, which comprises a floating double pulley having a support bracket and a pair of pulleys rotatably mounted on the same pivot axis on the support bracket in a side-by-side arrangement, a second floating pulley having at least one pulley, a first cable secured to the second floating pulley providing a first pulling point, a second cable secured to the double floating pulley providing a second pulling point, and a third cable extending around the single and double floating pulleys and providing third and fourth pulling points, whereby the system has at least four pulling points for selective linking to a load and exercise stations. 
     In one possible arrangement, the first cable is linked to a load such as a weight stack (100% load), the second cable is linked to a first exercise station, and the third cable extends around one of the pair of floating pulleys, then around the single floating pulley, and finally around the other of the pair of floating pulleys, providing two pulling points which may both be connected to exercise stations, or to one exercise station and one fixed point or cable tie-off, or to two cable tie-offs. In each case, the first exercise station has a 2 to 1 resistance ratio (200% of load), and the third cable has a 50% load at one or both ends. 
     In an alternative embodiment, a third pulley is secured to the double pulley support bracket beneath the pair of pulleys. In this case, the second cable extends around the third pulley to provide two pulling points at 100% of load each. These may both be connected to exercise stations, or one may be connected to a fixed cable tie-off. 
     The second floating pulley assembly may be a single pulley, or alternatively may comprise a pair of vertically aligned pulleys. In this case, the first cable extends around the uppermost pulley of the pair to provide two pulling points, one of which may be linked to the load or weight stack. This arrangement provides a 4 to 1 resistance ratio between the first cable and the second cable, where the first floating pulley assembly has a double pulley only. Alternatively, where a third pulley is mounted on the first floating pulley assembly, two pulling points at a 2 to 1 resistance ratio are provided. At the same time, the third cable in this arrangement provides two pulling points at 100% of load, or 1 to 1, and the first cable provides a third 100% pulling point. 
     According to another aspect of the present invention, a cable and pulley assembly is provided which comprises at least one floating pulley unit having a pulley housing and a pair of pulleys rotatably mounted side-by-side in the housing for rotation about a first pulley axis, a first cable linked to the pulley housing, a second cable extending around the pair of side by side pulleys and having opposite ends, and the resistance on the first cable being four times that at one end of the second cable. 
     In one alternative, the first cable is connected to the pulley housing at one end and has a resistance of four times that at one end of the second cable. In another alternative, a third pulley is rotatably mounted on the first pulley unit housing for rotation about a second pulley axis spaced from the first pulley axis, and the first cable extends around the third pulley and has opposite ends, the resistance at each end of the first cable being twice that at one end of the second cable. The third pulley axis is preferably perpendicular to the first pulley axis. 
     Each cable end may be selectively linked to an exercise resistance, a cable tie-off, or an exercise station. In some embodiments, a second floating pulley unit having a housing and a third pulley rotatably mounted in the housing is linked to the first floating pulley unit. The second cable extends around the third pulley, and a third cable is linked to the second pulley unit housing and to an exercise resistance, tie-off, or exercise station. The third cable may extend around a pulley rotatably mounted on the exercise resistance or weight stack, so that the end of the third cable may also be linked to an additional exercise station. In another alternative, the second cable extends from one of the side-by-side pulleys in a cable path extending around a pulley rotatably mounted on the weight stack or exercise resistance, and then back around the other of the side-by-side pulleys, so that the same cable links the first floating pulley unit to the load and still has opposite ends free for linking or connecting to different exercise stations. 
     This system permits five or more exercise stations to be linked to a resistance or load with a cable and pulley system where the pulleys are in line, on top of one another, rather than spreading out sideways as was necessary in the past. It therefore takes up much less space on the frame. Also, much fewer pulleys and pulley support brackets are required, and the streamlined design will enhance the appearance of the overall machine. The ability to provide two 2 to 1 resistance cables in one floating pulley was also not an option in previous systems. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will be better understood from the following detailed description of some preferred embodiments of the invention, taken in conjunction with the accompanying drawings, in which like reference numerals refer to like parts, and in which: 
     FIGS. 1A to  1 C illustrate three basic prior art floating pulleys used in prior art cable and pulley systems; 
     FIGS. 1D to  1 F illustrate various prior art cable and pulley systems using these floating pulleys; 
     FIG. 2 is a perspective view of a double floating pulley assembly forming part of some embodiments of the cable and pulley system of this invention; 
     FIG. 3 is an end elevational view of the pulley assembly of FIG. 2; 
     FIG. 4 is a perspective view of a triple floating pulley assembly according to another embodiment of the invention; 
     FIG. 5 is a perspective view of a first cable and pulley system according to one embodiment of the invention using the double pulley assembly of FIGS. 2 and 3; 
     FIG. 6 is a perspective view of a second cable and pulley system according to another embodiment of the invention, using the triple pulley assembly of FIG. 4; 
     FIG. 7 is a perspective view illustrating a modification of the system of FIG. 6; 
     FIG. 8 is a perspective view of a third cable and pulley system utilizing the double pulley assembly of FIGS. 2 and 3; FIG. 9 is a perspective view illustrating a modification of the system of FIG. 8; 
     FIG. 10 is a perspective view of a cable and pulley system according to another embodiment of the invention, using the triple pulley assembly of FIG. 4; 
     FIG. 11 is a perspective view of another embodiment of the cable and pulley system; 
     FIG. 12 is a schematic side elevation view illustrating one alternative for linking the cable and pulley assembly of FIG. 8 to a weight stack; 
     FIG. 13 is a schematic view similar to FIG. 12 illustrating addition of another cable and pulley assembly to provide extra pulling points; 
     FIG. 14 illustrates a modification of the assembly of FIG. 13; 
     FIG. 15 is a schematic side elevation view of the cable and pulley assembly of FIG. 5 linked to a weight stack; 
     FIG. 16 illustrates a modification of FIG. 15 in which two cable and pulley assemblies are linked to the weight stack; 
     FIG. 17 is a schematic side elevation view of a modified cable and pulley assembly with one side-by-side pulley unit linked directly to a weight stack; and 
     FIG. 18 is a schematic side elevation view of an alternative side-by-side pulley unit which may replace any of the side-by-side pulley units illustrated in FIGS. 12 to  17 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIGS. 1A to  1 F illustrate the capabilities of some of the prior art pulley and cable systems, so that they may be compared to the cable and pulley systems of this invention as illustrated in FIGS. 2 to  18 . 
     FIG. 1A illustrates a simple, prior art single floating pulley  10  with a first cable  12  linked to the pulley housing  14  and a second cable  16  extending around the pulley. This arrangement provides one weight stack or load connection point  18  and two possible exercise pulling points  19 , 20 , one at a 100% or 1:1 resistance ratio, and one at a 200% or 2:1 resistance ratio. The single floating pulley may be reversed, with point  20  attached to the load and points  18 , 19  providing two 50% or 1:2 resistance ratios. 
     In FIG. 1B, a prior art double floating pulley is illustrated in which two pulleys  21 , 22  are stacked vertically one on top of the other in pulley housing  24 . In this case, a first cable  25  extends around one of the pulleys and a second cable  26  extends around the other pulley, providing one weight stack or load attachment  27  and three 100% or 1:1 pulling points  28 . 
     FIG. 1C illustrates another prior art floating pulley arrangement. In this arrangement, a single floating pulley  30  is mounted in a housing  31  to which two, oppositely directed cables  32 , 33  are secured. One of the cables  32  extends around a fixed pulley  34 , then back around the single floating pulley  30 . If the free end  35  of this cable is secured to the load or weight stack, the pulling point  36  on cable  33  has a 300% or 3:1 resistance ratio. 
     Thus, existing floating pulleys can provide resistance ratios of 1:2 (50% of load), 1:1 (100% of load), 2:1 (200% of load), and 3:1 (300% of load). 
     FIGS. 1D to  1 F illustrate some prior art cable and pulley systems using combinations of these floating pulleys. FIG. 1D illustrates a combination of three single floating pulleys  10  in which each pulley has a single cable  12  connected to housing  14 , and a cable  38  extends around all three pulleys  10 . If the central cable  12  is connected to the weight stack, the opposite ends of cable  38  provides two 50% pulling points, while each of the other two cables  12  provide a 100% pulling point. 
     In FIG. 1E, a combination of two single floating pulleys  10  and a double floating pulley  21 , 22  is illustrated. In this case, the cable  25  extending around the lowermost pulley  21  of the double floating pulley has opposite ends extending around respective single floating pulleys  10 . In this combination, one end of cable  26 , for example, can be connected to the weight stack, providing a 100% pulling point at the opposite end of cable  26  as well as at each end of cable  25 . Each cable  12  will provide a 200% pulling point. 
     FIG. 1F illustrates an alternative arrangement of three single floating pulleys  10  to provide three 100% pulling points and one 400% pulling point. 
     In each of these floating pulley combinations, the floating pulleys spread out sideways to increase the number of pulling points, considerably increasing space requirements. Additionally, at least three floating pulleys and pulley housings are needed to provide four pulling points, and additional floating pulleys must be provided for additional exercise stations, thus the system spreads out sideways even more in such arrangements, increasing space requirements. 
     FIGS. 2 to  4  of the drawings illustrate two alternative floating side-by-side pulley units  40 , 50 , respectively, of the present invention which are at the heart of each of the alternative embodiments of the cable and pulley linkage of the invention as illustrated in FIGS. 5 to  18 . FIGS. 2 and 3 illustrate a double floating pulley unit  40  according to a first embodiment and FIG. 4 illustrates a triple floating pulley unit  50  according to a second embodiment of the invention. The double floating pulley unit  40  basically comprises a generally U-shaped pulley housing  42  having a cable tie-off  44  extending from its base wall  45 . A pair of side-by-side pulleys  46  are rotatably mounted on a single pulley axle  48  extending between the side walls  49  of the pulley housing. This pulley device is used in the cable and pulley linkage systems of FIGS.  5 , 8 , 9 , 11  and  12  to  17 . 
     The triple floating pulley unit  50  illustrated in FIG. 4 is a modification of the double floating pulley device of FIGS. 2 and 3, and like reference numerals are used for like parts as appropriate. However, the cable tie-off  44  is replaced with a single pulley housing  52  in which a single pulley  54  is rotatably mounted for rotation about an axis  55  perpendicular to the double pulley axle or axis  48 . 
     The double and triple floating pulley units of FIGS. 2 to  4  may be used in a number of different configurations to produce a more versatile and compact pulley and cable linkage for a multiple station, weight lifting exercise machine. Some of these alternatives are illustrated in FIGS. 5 to  18 . In these embodiments, like reference numerals have been used for like parts as appropriate. In each of these embodiments, any cable end may selectively be attached to the frame of an exercise machine, attach to a single floating pulley, or continue on to an exercise station. 
     One possible linkage using the double floating pulley unit  40  is illustrated in FIG.  5 . In this linkage, a first cable  56  is secured to the cable tie-off  44  and a second cable  58  extends from a fixed point or tie off  60  on the frame, or a movable arm, around a first one of the pair of pulleys  46 , then around a single floating pulley  62  positioned above the double pulley unit  40 , and finally back around the second one of the pulleys  46 . The free ends of cables  56  and  58  can be connected to different exercise stations, while a third cable  64  connects the single pulley unit  62  to a load such as a weight stack. A 1:2 or 50% resistance is thus provided at the end of cable  58 , while a 2:1 or 200% resistance is provided at the end of cable  56 . The cable  56  thus has a resistance four times that at each end of cable  58 . 
     The arrangement of FIG. 5 may be connected in different configurations. For example, both ends of cable  58  may be connected or linked by additional pulleys to exercise stations, providing two 50% pull points as well as the 200% pull point. In another alternative, both ends of cable  58  may be connected to fixed points on the frame, or tie-offs  60 , providing a single 2:1 or 200% exercise pull point. Alternatively, tie-offs  60  may be on one or more movable arms. 
     FIG. 6 illustrates another possible cable and pulley linkage which uses the triple floating pulley unit  50  in combination with a single floating pulley  62  as in the previous embodiment. A first cable  65  extends around the lower, single pulley  54  of unit  50 , while the cable  58  is arranged as in the previous embodiment, extending around one of the two pulleys  46 , then around the single pulley  62 , and then back down around the second of the pulleys  46 . In the illustrated embodiment, both ends of cable  58  are connected to exercise stations, cable  64  is connected to the weight stack, and both ends of cable  65  are also connected to exercise stations, providing four pull points in an in-line arrangement. Each end of cable  58  will have a 1:2 or 50% resistance while each end of cable  65  has a 1:1 or 100% resistance. 
     The cables in FIG. 6 can also be connected differently to provide different combinations of pull points. For example, one or both ends of cable  58  may be connected to fixed tie-offs or movable arms, if a reduced number of exercise stations are involved. FIG. 7 illustrates another alternative in which one end of cable  65  is connected to a fixed tie-off or movable arm  66 , and one end of cable  58  is also connected to a fixed tie-off or movable arm  67 , so that the opposite ends of cables  65  and  58  can be used as 100% and 50% pull points, respectively, at different exercise stations. In this case there are only two exercise stations. Alternatively, both ends of cable  58  may be connected to exercise stations, providing three pull points or exercise station connections, two at 50% and one at 100%. 
     FIG. 8 illustrates another alternative cable and pulley assembly using the double floating pulley unit  40  of FIGS. 2 and 3 in combination with a double floating pulley unit  70  which has two pulleys  72  positioned in a vertically spaced configuration, with the pulleys in line on top of one another, in a pulley housing  73 . The vertically stacked double pulley unit  70  is spaced above the side-by-side floating pulley unit  40 . A first cable  74  is connected to the tie-off  44  at the bottom of unit  40 . A second cable  75  extends around one of the two pulleys  46 , then around the lowermost of the pulleys  72 , and then back around the other of the two pulleys  46 . A third cable  76  extends around the uppermost pulley  72  of unit  70 . In this assembly, one end  78  of cable  76  is preferably connected to the load or weight stack. The other four cable ends may be connected to exercise stations, if desired. The other end of cable  76  and both ends of cable  75  each have a 1:1 resistance ratio, or 100% of load, as indicated in the drawing. The end of cable  74  will have a 4:1 resistance ratio, i.e. 400% of load. Therefore, this cable and pulley assembly increases the resistance of an incoming, load-bearing cable by four times, in a compact, in line arrangement, which was not possible in any prior art cable and pulley systems. 
     Instead of connecting both ends of cable  75  to exercise stations, as in FIG. 8, one or both ends of cable  75  may be connected to a fixed tie-off point or bracket on the support frame of the exercise machine, if fewer exercise stations are used, or to a moveable arm, or to additional pulleys. 
     FIG. 9 illustrates another modification of the assembly of FIG. 8, in which the opposite end of cable  76  to the load is connected to a fixed tie-off or bracket  80 , and one end of cable  75  is also connected to a fixed tie-off or bracket  81 . In each of these alternatives, the lower cable  74  still has a 4:1 resistance ratio, or 400% of load, and two or three additional pull points at 100% are provided. 
     FIG. 10 illustrates another modified cable and pulley assembly which uses a double, vertically stacked floating pulley  70  as in FIG. 8 and 9, but in combination with the triple floating pulley unit  50  rather than the double pulley unit  40 . As in the previous embodiment, upper cable  76  extends around the uppermost pulley  72 , and a cable  75  connects the lowermost pulley  72  to the side by side pulleys  46  of pulley unit  50 . As in the previous embodiment, cable  75  extends around one of the pulleys  46 , lowermost pulley  72 , and then around the other pulley  46 . A cable  82  extends around the lower pulley  54  of the triple pulley unit  50 . One end  83  of cable  76  may be connected to the load or weight stack, and up to five exercise stations may be connected to the other cable ends, i.e. the opposite end of cable  76  and each end of the cables  75  and  82 . 
     In this arrangement, the free end of cable  76  has a 1:1 resistance ratio, or 100% of load, as do the opposite ends of cable  75 . The opposite ends of the lowermost cable  82  each have a 2:1 resistance ratio, or 200% of load. This assembly provides pull points for up to five exercise stations in a simple, in line arrangement, whereas in the past such a large number of exercise stations would have required a cable and pulley system which extended sideways and took up much more room than the illustrated assembly. 
     There are a number of possible configurations for the cable ends of the assembly of FIG.  10 . In the illustrated embodiment, each cable end apart from the load bearing cable end is connected to an exercise station. However, one or both ends of the central cable  75  may be connected to a fixed tie-off on the frame, or to a moveable arm, providing only one or two 100% pull points rather than three as in FIG.  10 . This may be appropriate for machines having less than five exercise stations, for example. Alternatively, one or both ends of the lower cable  82  may be connected to a fixed tie-off, providing one 200% pull point or only 100% pull points, as desired. In another possible alternative, one end of cable  75  and one end of cable  82  may be connected to a fixed tie-off. This arrangement would provide two 100% pull points and one 200% pull point. In another alternative, both ends of cable  75  and one end of cable  82  may be connected to fixed tie offs, providing one 100% pull point at the free end of cable  76  and one 200% pull point at the free end of cable  82 . 
     In another possible alternative, the opposite end of cable  76  to the load may be connected to a fixed tie-off, with both ends of each of the cables  75  and  82  connected to exercise stations, or with one or more of these cable ends connected to fixed tie-offs, depending on the number and location of pull points required. The cable ends may alternatively be connected to a moveable arm rather than to a fixed tie-off. 
     The cable and pulley assembly of FIG. 10 therefore has great versatility, permitting any number of exercise stations from two to five to be connected to the assembly, in various combinations of 100% and 200% resistance as desired. The assembly is simple and compact, with only two floating pulley units linked in line without spreading sideways which is normally the case in systems involving four or more pull points or exercise stations. 
     FIG. 11 illustrates another alternative cable and pulley assembly, which is similar to that of FIG. 9, combining the double, side-by-side pulley unit  40  with a double, vertically spaced pulley unit  70 , but includes an additional, single floating pulley unit  62  between units  40  and  70 . In this assembly, a first cable  84  is connected to the cable tie-off  44  of unit  40 , a second cable  85  extends between unit  40  and the single floating pulley unit  62 , a third cable  86  extends between unit  62  and the lowermost pulley  72  of unit  70 , and a fourth cable  88  extends around the uppermost pulley  72  of unit  70 . 
     In the illustrated embodiment, a number of pull points which are vertically spaced and in line are provided. One end  89  of cable  88  may be connected to a weight stack. The other end of cable  88  may be connected to an exercise station at a 1:1 resistance ratio (100% of load). Cable  86  has one end secured to the housing of single cable unit  62 , and the opposite end is secured to a cable tie-off  90 , which may be on the fixed frame of the exercise machine, or on a movable arm. Alternatively, the free end of cable  86  may be connected to an exercise station, and in this case it will have a 1:1 resistance ratio, or 100% of load. 
     The opposite ends of cable  85  may each be linked to exercise stations, and will each provide a 1:2 resistance ratio, or 50% of load. Alternatively, one or both ends of cable  85  may be connected to a cable tie-off mounted either on the fixed frame of the machine or on a movable arm. The end of cable  84  may be linked to an exercise station to provide a 2:1exercise ratio, or 200% of load. 
     The assembly of FIG. 11 provides an arrangement of three floating pulley units in line, one on top of the other, providing up to five pull points for appropriate connection or linkage to exercise stations, with resistance ratios of 1:1,2:1, and 1:2. In an alternative assembly (not illustrated), the double pulley unit  40  may be replaced with the triple pulley unit  50  of FIG. 4, providing one more pulling point, in an equivalent manner to FIGS. 7 and 10. In this case, a cable will pass around the lowermost pulley  54  of the triple pulley unit to provide two possible pull points at 100% of load each. One or more of the cable ends in this arrangement may also be selectively connected to a cable tie-off on the frame or a movable arm. 
     FIG. 12 schematically illustrates a side-by-side pulley unit  40  in an arrangement as illustrated in FIG. 8, and like reference numerals have been used for like parts as appropriate, and indicates one possible arrangement for linking cable  76  to a weight stack  78 . In the arrangement of FIG. 12, the third cable  76  linked to the weight stack  78  via a series of pulleys  110 , 112 , 114 , with pulley  112  rotatably mounted at the top of the weight stack. This leaves one end  116  of the cable free for providing another exercise pull point. The opposite end  118  of the cable  76  extends around a further pulley  120  and may also be linked to an exercise station. This arrangement provides the loads as indicated at the various pulling points. It will be understood that any of the five free cable ends illustrated in FIG. 12 may selectively be attached to the frame, to a single pulley, or continue on to an exercise station. 
     FIG. 13 illustrates a modification of the assembly of FIG. 12, in which an additional side-by-side pulley unit  40  is linked to the cable  76  on the opposite side of weight stack  78 . The pulley unit  40  on the left hand side of the weight stack as viewed in FIG. 13 is linked to a single floating pulley  62  in an arrangement similar to that illustrated in FIG. 5, and like reference numerals to those used in FIGS. 5,  8 , and  12  have been used for like parts as appropriate. 
     In the arrangement of FIG. 13, the cable  76  continues on from single pulley  114  on the opposite side of the weight stack to pulley units  40  and  70 , and is linked to the housing of single floating pulley  62  as illustrated. This provides additional pulling points at various different percentages of the weight stack load, which may be used at different exercise stations. In FIG. 13, a total of seven possible pulling points is provided. 
     FIG. 14 illustrates a modification of the assembly of FIG. 1 3 , in which the single floating pulley  62  on the left hand side of the weight stack is replaced with a double floating pulley unit  70 , as on the right hand side. In this case, cable  76  wraps around the upper pulley  72  of pulley unit  70  and continues on for selective connection to an exercise machine frame, a further exercise station, or another single pulley. This arrangement provides eight possible pulling points with the indicated loads at the various cable ends. 
     FIG. 15 illustrates an assembly similar to that of FIG. 12 but with the side-by-side pulley unit  40  linked to a single floating pulley unit  62  in an arrangement similar to that of FIG.  5 . The cable  64  secured to the housing of the single pulley unit  62  extends around pulleys  110 , 112 , and  114 , with pulley  112  being rotatably mounted at the upper end of weight stack  78 . Thus, cable  64  is linked to the weight stack while still providing a potential pulling point for linking to another exercise station, a cable tie off on the frame of the exercise machine, or a further pulley. 
     FIG. 16 illustrates a modification of the assembly of FIG. 15 in which an additional side-by-side pulley unit  40  is linked to a single pulley unit  62  as in FIG. 5, and the housing of the second pulley unit  62  is linked to the end of cable  64 , providing an additional three pulling points. Thus, in FIG. 16, a cable  64  extends from the first single pulley unit  62  on one side of the weight stack, around pulleys  110 , 112 , and  114 , and is then linked to the second single pulley unit on the opposite side of the weight stack. 
     FIG. 17 illustrates another possible configuration of a cable and pulley assembly using a side-by-side pulley unit  40 . In this configuration, a first cable  122  is linked to the housing  45  of the pulley unit  40 . A second cable  124  engages the load or weight stack  78  and feeds the side-by-side pulleys  46 . Cable  124  extends around one of the side-by-side pulleys  46 , then around a sequence of four single pulleys  125 , 126 , 127 , 128  before extending around the other pulley  46  of the floating pulley unit  40 . Pulley  126  is rotatably mounted on top of the weight stack  78 , or may be suitably linked to the weight stack via an additional cable (not illustrated). This provides three possible pulling points at the indicated load percentages. 
     FIG. 18 is a schematic illustration of the side-by-side pulley unit  50  of FIG. 4 which has two side-by-side pulleys  46  and a third pulley  54  mounted on the housing beneath pulleys  46 . The cable  58  extending around pulleys  46  is shown extending around a single floating pulley in a pulley unit  62 , as also illustrated in FIG.  6 . It will be understood that any of the side-by-side, two pulley units  40  of FIGS. 12 to  17  may be replaced with a three pulley unit  50  as illustrated in FIG. 18 in alternative configurations. Additionally, it will be understood that any cable end may attach to the frame, to a single floating pulley, or extend on to an exercise station. 
     The cable and pulley assembly of this invention requires less pulleys and pulley housings to provide a plurality of possible pull points at varying resistance ratios of 1:2, 1:1, 2:1, and 4:1. The design is relatively compact, since two or more floating pulley units are positioned in line on top of one another, instead of spreading out sideways as in prior art arrangements. 
     This provides a much less bulky and more pleasant appearance in the machine. The assembly can provide a resistance ratio of up to 4:1, as in FIGS. 8 and 9, and can provide two, three, four, five or six pull points for linking to various exercise stations, as desired. A combination of the pulley unit  50  in the arrangement of FIG. 12 provides six pulling points, and with FIG. 14 provides ten pulling points. A number of the alternatives provide two 2:1 resistance cables or pull points in a single floating pulley, such as the assembly of FIG.  10 . This invention provides a double, side-by-side pulley unit or triple floating pulley unit in combination with at least one additional floating pulley unit in a large number of different possible configurations. Additionally, the triple floating pulley unit  50  provides more pulling points from a single location than was possible in any prior art arrangement. 
     It will be understood that the alternative cable and pulley assemblies of FIGS. 5 to  18  are just some of the possible configurations which may be obtained by combining the floating pulley unit  40  and/or  50  with other single or double pulley units. The double, side-by-side pulley unit  40  in combination with a cable fed around both pulleys provides two pulling points with the original resistance, and a third pulling point with four times the original resistance (see FIG.  8  and  9 ), or in the triple unit of FIG. 4, two pulling points with two times the original resistance (e.g. FIG.  10 ). 
     The side-by-side pulley unit of this invention, in combination with a cable that feeds around both of the side-by-side pulleys, gives more pulling points and the ability to perform more exercises off a single load or weight stack. Numerous possible variations are possible, depending on what resistance is desired at each of the pulling points, and combinations with pulling points at various different resistances are possible. 
     Although some preferred embodiments of the invention have been described above by way of example only, it will be understood by those skilled in the field that modifications may be made to the disclosed embodiments without departing from the scope of the present invention, which is defined by the appended claims.