Exercise apparatus and method with sliding handle assembly

[0001] The present invention relates to an exercise apparatus and method with a slidable handle assembly, the apparatus and method being useful, in one example, for developing the muscles used during trunk rotation of a user in a standing position.

[0002] Physical exercise apparati have been designed in the past which enable a user to perform a variety of different exercises. A user, typically standing or sitting in front of the machine, pulls or pushes against various resistance mechanisms, such as a resistance cable attached to a weight stack. One particular exercise motion that is used in basically in every sport is known as trunk rotation, and comprises a combination of a hip rotation and a spinal rotation. For example, when a user swings a golf club or a baseball bat, or throws a football or a punch, a trunk rotation motion is required. Thus, it would be desirable to provide an exercise apparatus that develops the muscles utilized during such motion.

[0003] An apparatus and method are provided in accordance with the present invention in which a pair of opposing pulleys are slidably mounted over an elongated rod. The pulleys are interconnected by a pull cable having a hand grip at each end wherein a user grasps a respective one of the hand grips causing the associated pulley to slide along a length of the rod toward the opposing pulley, thus maintaining the moving pulley in substantial alignment with the longitudinal axis of the elongated rod. In this manner, a substantially upright (e.g., standing or kneeling) user grasping one hand grip and moving it away from the longitudinal axis of the elongated rod (e.g., across his upper torso while twisting his upper torso) can develop the muscles utilized during trunk rotation while maintaining a substantially constant torque about the user's spine during the exercise. This avoids the problems of the prior art apparatus and methods in which a pull cable may wrap around the user's trunk, which causes a significant reduction in torque around the spine.

[0004] In accordance with one embodiment of the invention, an exercise apparatus is provided comprising:

• • [0005] an elongated rod mounted on a frame, the rod having a longitudinal axis and first and second ends;
  • [0006] a pair of pulleys each mounted on an associated sleeve that is slidably mounted on the elongated rod;
  • [0007] each of the pulleys being interconnected to a force resistance mechanism and adapted to be held in a stable rest position at respective ones of the first and second ends of the elongated rod;
  • [0008] the pulleys each comprising a respective pulley wheel, the pulleys being interconnected by a pull cable having opposing ends wound around and interconnecting the pulley wheels;
  • [0009] each end of the pull cable being interconnected to an associated hand grip;
  • [0010] the interconnection between the pulleys and the force resistance mechanism being arranged such that when the user grasps a selected one of the hand grips and moves the hand grip away from the longitudinal axis, the pulley associated with the selected hand grip is slidable along the longitudinal axis of the elongated rod under forcible resistance from the force resistance mechanism.

[0011] In one embodiment, wherein the ends of the elongated rod are adjustably mounted to the frame such that the longitudinal axis is adjustable to one of a plurality of fixed vertical positions of selectively variable height relative to a ground surface on which a user is disposed for performing an exercise.

[0012] In one embodiment, the pulleys are interconnected to the force resistance mechanism via a connector cable.

[0013] In one embodiment, the connector cable is interconnected to each of the sleeves on which the pulleys are mounted.

[0014] In one embodiment, the rod is adjustably mounted to the frame via a frame member that pivots with respect to the frame.

[0015] In one embodiment, the elongated rod is mounted to the frame such that the rod is stationary against rotation transverse to its longitudinal axis.

[0016] In one embodiment, the elongated rod is mounted to the frame such that the longitudinal axis of the rod is disposed generally parallel to the ground surface at all fixed vertical positions of the rod.

[0017] In accordance with another embodiment of the invention, a method of performing a muscle exercise comprises providing an exercise apparatus comprised of a frame stationary with respect to a ground surface on which a user is disposed for performing an exercise, an elongated rod mounted on the frame having a longitudinal axis and first and second ends, a pair of pulleys each mounted on an associated sleeve that is slidably mounted on the elongated rod, wherein each of the pulleys is interconnected to a force resistance mechanism and wherein the pulleys are interconnected by a pull cable having opposing ends each interconnected to an associated hand grip engageable by the user, the method further comprising:

• • [0018] the user grasping a selected one of the hand grips and moving the selected grip away from the longitudinal axis of the rod with a degree of force sufficient to overcome the force resistance mechanism such that the pulley and sleeve associated with the selected hand grip slides along the longitudinal axis of the elongated rod.

[0019] In accordance with another embodiment of the invention, an exercise apparatus is provided comprising:

• • [0020] an elongated rod mounted on a frame, the rod having a longitudinal axis and first and second ends;
  • [0021] a pair of pulleys each mounted on an associated sleeve that is slidably mounted on the elongated rod;
  • [0022] each of the pulleys being interconnected to a force resistance mechanism and adapted to be held in a stable rest position at respective ones of the first and second ends of the elongated rod;
  • [0023] the pulleys each comprising a respective pulley wheel, the pulleys being interconnected by a pull cable having opposing ends wound around and interconnecting the pulley wheels;
  • [0024] each end of the pull cable being interconnected to an associated hand grip;
  • [0025] the interconnection between the pulleys and the force resistance mechanism being arranged such that when the user grasps a selected one of the hand grips and moves the hand grip away from the longitudinal axis, the pulley associated with the selected hand grip is slidable along the longitudinal axis of the elongated rod under forcible resistance from the force resistance mechanism; and
  • [0026] the rod being mounted on the frame such that the longitudinal axis of the rod is disposed in a generally horizontal orientation.

[0027] In one embodiment, the rod is adjustably mounted to the frame on a pivot arm structure, wherein the arm structure rotates with respect to the frame for adjusting the height of the rod above a ground surface on which a user is disposed.

[0028] In one embodiment, the apparatus includes a pivot adjustment mechanism including a support plate mounted on the frame with a plurality of apertures disposed in a circumferential array for adjusting the rotable position of the arm structure with respect to the frame.

[0029] In one embodiment, the sleeves are each interconnected to the force resistance mechanism via a connector cable and the connector cable engages one or more pulley wheels mounted to the pivot arm structure.

[0030] In one embodiment, the connector cable is assembled together with the sleeve for free rotation independent of the sleeve around the elongated rod.

[0031] In one embodiment, the sleeve is mounted for rotation about the longitudinal axis of the rod.

[0032] In accordance with another embodiment of the invention, an exercise apparatus is provided comprising:

[0033] an elongated rod mounted on a frame having a longitudinal axis;

[0034] a pair of pulleys each mounted on an associated sleeve adapted to slide along the elongated rod;

[0035] a pull cable having opposing ends wound around and interconnecting the pair of pulleys, each end of the cable being connected to an associated hand grip;

[0036] each pulley being slidable together with its associated sleeve along the elongated rod via a user grasping the associated hand grip and moving the hand grip away from the longitudinal axis; and

[0037] wherein the sleeves are interconnected to a force resistance mechanism holding the sleeves at opposing ends of the elongated rod under a selected resistance force.

[0038] In one embodiment, the hand grip is rotatable with respect to its associated sleeve.

[0039] In one embodiment, the elongated rod has a longitudinal axis, the rod being mounted on the frame such that the rod is disposed in a generally horizontal orientation.

[0040] In one embodiment, the elongated rod is mounted on the frame such that the longitudinal axis is selectively adjustable to one of a plurality of fixed positions of selectively variable vertical distance relative to a ground surface on which the user is supported.

[0041] In one embodiment, the sleeves are each interconnected to a force resistance mechanism via a connector cable.

[0042] In one embodiment, the force resistance mechanism comprises a plurality of incremental force resistance elements that are selectively engagable by the user with the connector cable.

[0043] In one embodiment, each of the sleeves are assembled together with respective collars, the sleeves being mounted together with the respective collars for free rotation around the elongated rod, the collars being interconnected to a respective opposing end of a connector cable, the collars being assembled together with the sleeves for free rotation independent of the sleeves around the elongated rod.

[0044] In one embodiment, the connector cable has opposing ends interconnected to respective ones of the sleeves, the connector cable having a portion intermediate the opposing ends engageable with the force resistance mechanism.

[0059] One embodiment of the apparatus of the present invention will now be described, which is meant to illustrate and not limit the scope of the claimed invention. Other embodiments and variations will be apparent to the skilled person and are intended to be included with the scope of the appending claims.

[0060] For ease of description, the left and right side frame elements and left and right side rotatable arm/handle assemblies are generally referred to as sub-elements a (left) and b (right) and are given the same reference number. The apparatus is essentially symmetrical with each of the left and right side frame, rotatable arm/handle assemblies, cable and pulley assemblies being the same. Thus, in some instances the sub-assembly only on one side will be described, it being clear from the drawings and reference numbers that the other side sub-assembly is the mirror image.

[0061] FIG. 1 is an overall view of an exercise apparatus 10 according to one embodiment of the invention. The apparatus includes a generally upright frame 11 which rests on a horizontal ground surface 2. The frame includes a lowermost base member 14, a vertical support structure 22 that includes an adjustable weight stack 150, and a C-shaped pivoting arm structure 50 adjustably mounted on the frame 11 for lowering or raising a front horizontal rod 12 extending between the two front ends of the C-shaped arm structure 50. A pair of left and right handle bracket assemblies 60a, 60b with respective left and right hand grips (e.g., handles) 90a, 90b are slidably mountable on the rod 12 for engagement by a user. When a user, standing in front of the machine 10, pulls the handle of on one of the handle assemblies, that handle will move (extend) toward the user as the associated handle bracket slides across the rod 12 in the direction of the opposing handle bracket. This sliding motion will be further described in the following detailed description and accompanying figures.

[0062] As shown in FIGS. 1-7, the rod 12 comprises an elongated cylindrically shaped rod having a longitudinal axis LA, the rod being mounted on the frame such that the longitudinal axis is disposed generally horizontally relative to the ground surface plane P2 which supports the frame and a user.

[0063] The apparatus 10 includes a base member 14 disposed generally parallel and adjacent to the horizontal plane P2 of the ground surface 2. The base 14 includes left and right elongated feet members 15a, 15b, joined by a cross bar 17. At the ends of each foot are mounting pads 16 with holes for bolting the front and rear ends of the feet to the ground surface 2 to maintain the machine in a stationary position. On top of the central cross bar 17 there is mounted a central vertical column or support 22 including a vertically-disposed housing 23 that encloses a weight stack 150. The housing includes left and right end supports (e.g., hollow tubes) 24a, 24b that are joined by a top support (e.g. hollow tube) 25, along with a front cover 26 and a rear cover 27 that define a central cavity 28 in which the weight stack resides. An elongated vertical opening 29 in the front cover 26 provides access to an adjustable pin 154 for selecting a number of weights in the stack to be attached to a connector (resistance) cable, thereby adjusting the amount of force required by the user to extend the pull handle assemblies 60a, 60b.

[0064] In the present embodiment, the rod 12 on which the slidable handle bracket assemblies 60a and 60b are mounted, forms one side of a rectilinear pivot arm structure 50. This is by way of example only, as other mechanically rigid support structures can be used for pivotably mounting the rod 12 to the frame 11. In this embodiment, the arm structure 50 includes left and right side arms 52a, 52b each joined at their rear ends to opposite ends of a transverse rear arm 51, wherein all three arms and the front rod 12 lie in a single horizontal plane P50 that in FIG. 1, is substantially parallel to the ground surface plane P2. This is referred to herein as the middle or central position, also illustrated (in use) in FIG. 2A. With the pivot arm 50 in the middle position, the front rod 12 is in the same horizontal plane P50 as the arm structure 50, parallel to the ground surface plane, and the rod 12 is disposed roughly three feet above the ground surface plane P2. This central position provides easy access by a user standing in front of the machine 10 and rod 12 for engaging and grasping the handles 90a, 90b in order to pull on the handle(s) and as a result slide the handle bracket(s) across the rod 12 (as shown in FIG. 2A).

[0065] To vary the direction of extension and range of motion of the user, the arm structure 50, including left and right side arms 52a, 52b and supporting rod 12, can be pivoted about a generally horizontal axis A which is disposed parallel to the ground surface plane P2. Pivoting the arm structure 50 clockwise about the axis A enables the user to raise the front rod 12 upwardly, so that the handle assemblies are now further away from the ground surface 2 (e.g., about five feet above the ground 2) than in the middle position, while still maintaining the rod 12 in a plane substantially parallel to the ground surface plane P2. Alternatively, pivot arm 50 can be pivoted in the opposite direction (counterclockwise), lowering the rod 12 so that the handles are now closer to the ground (see FIG. 2B), and a user 4 disposed in front of the machine now will pull upwardly on the handles. Again, the rod 12 is always maintained in a substantially horizontal plane parallel to the ground surface plane P2, but the distance from the ground surface plane varies depending on the pivoted position of arm structure 50 on frame 11.

[0066] FIG. 2A illustrates the cooperation of multiple pulley cable assemblies during use, including two handle pulley assemblies 70a, 70b engaging opposite ends of the pull cable assembly 68 and a connector (resistance) cable assembly 30 engaging the weight stack. Relevant portions of these assemblies are shown in FIG. 2A where a user 4 is performing an exercise with the support arms 52a, 52b in a horizontal middle position (same as FIG. 1). The pull cable assembly 68 is directly engaged by the user; it includes a pull cable 80 having a left end 81 engagable with the left slidable handle bracket 60a, and a right cable end 82 engagable with the right slidable handle bracket 60b. The left and right handle brackets 60a, 60b are initially disposed at opposing left and right ends 13a, 13b of the rod 12 (prior to use, as shown in FIG. 1). When a user grasps the grip 91b of right handle 90b and pulls it toward himself, as shown by arrows A1 in FIG. 2A, the right handle bracket 60b is caused to slide across the rod 12 toward the left handle bracket 60a, the latter being fixed in position on the left hand end 13a of rod 12 by its engagement with the resistance cable assembly 30 attached to the weight stack 150.

[0067] More specifically, the right handle bracket 60b includes a slidable sleeve (e.g., tube) 62b having a central bore 63b which slidably engages the outer cylindrical surface of rod 12. A pulley housing 71b attached to slidable tube 62b mounts a pulley wheel 76b, over which a pull cable 80 can be pulled (by a user) while the wheel rotates. At the right end 82 of pull cable 80, a stop ball 83b is provided that prevents the pull cable from being pulled out of the handle bracket 60b when the user pulls on the opposing handle 90a. The right end 82 of cable 80 is attached by a metal ring 84b to a Y-shaped handle frame 92b. A grip 91b is supported across the open ends 94b of the Y-shaped frame 92b, wherein an opening 93b between the grip and Y-shaped frame allows the user's fingers to be inserted for grasping the grip 91b. The opposing end 95b of the Y-frame 92b has an aperture which receives the ring 84b for connecting the stop ball 83b between the handle 90b and pull cable 80.

[0068] The right handle bracket assembly 60b further includes a tabbed collar 130b attached to the slidable tube 62b for connecting the handle bracket 60b to the resistance cable assembly 30. More specifically, a first end 32 of resistance cable 31 is attached to the tab portion of the collar 130b. The resistance cable 31 extends from collar 130b around four right side pulley wheels 35b-38b, and then around a central pulley 42 which is attached to the weight stack 150. The opposing left end 33 of resistance cable 32 is similarly engaged with the left handle bracket 60a and a mirror image pulley assembly with four pulley wheels, and ultimately engages the same central pulley wheel 42 engaged with the same common weight stack 150. Thus, in the present embodiment, a single resistance cable assembly 30 connects the left and right slidable handle brackets 60a, 60b, while a separate pull cable assembly 68 similarly connects the left and right handle brackets 60a, 60b, and together the two separate cable assemblies 30 and 68, which each engage the left and right slidable handle brackets 60a, 60b, enable the resistance training motion and exercises illustrated in the figures.

[0069] Returning to FIG. 2A, when a user 4 grasps the right handle 90b (shown in phantom lines in its initial position) and pulls the handle 90b toward himself while moving away from the machine 10, thereby extending the right handle away from the rod 12, he pulls against the resistance set by the resistance cable assembly 30 which is attached to a select number of weights in the weight stack 150. Here, an adjustable pin 154 selects the upper 5 weights in the stack as a desired resistance level; while the user pulls on the right handle these upper 5 weights rise upwardly along the parallel guide rods 152 of the weight stack. As a result the right handle bracket 62b slides to the left on the rod 12, allowing the pull cable 80 to extend further toward the user while the user continues to exert sufficient force to overcome the selected weight resistance 151 (upper 5 weights of the stack). The left handle bracket 60a remains stationary with respect to the frame 11, the stop ball 83a preventing the pull cable 80 from disengaging with the left handle bracket, and the resistance cable 31 attached to the left handle bracket resisting the force on the pull cable 80 exerted by the user pulling on the right handle. FIG. 2A includes a series of arrows A2 that illustrate the movement of the resistance pull cable 31 around the various pulley wheels, including the right front side wheel 35b, right rear side wheel 36b, right central lower wheel 37b, right central upper wheel 38b, and the common wheel 42 attached to the weight stack. In FIG. 2A the rod 12 is in the middle position, parallel to the ground plane P2, and here about 3 feet above the ground surface.

[0070] In contrast, FIG. 2B shows the pivot arm structure 50 rotated counterclockwise about axis A to a lowermost position, wherein the rod 12 is now horizontally aligned in a plane PL much closer to the ground plane 2, here a minimum of about 45 inches above the ground. In this position, the user pulls upwardly on the right handle 90b, again overcoming the resistance of the selected weights in the weight stack, similar to FIG. 2A. This adjustability of the height at which the rod 12 is positioned and thus the position at which the handle bracket assemblies are provided, enables a wide range of motion for the user exercising with this single apparatus. FIG. 4 shows in phantom lines a third uppermost position in which the pivot arm structure 50 is pivoted in the opposite direction (clockwise) about axis A, causing the rod 12 to be raised above the middle position, to an uppermost position, in a horizontal plane about five feet above the ground surface. The adjustment mechanism for the pivot arm structure is described below, and may include additional positions between the uppermost and lowermost positions.

[0071] FIGS. 3A-3D illustrate the coordinated motion of the pull cable assembly 68 and the resistance cable assembly 30 in use. These figures show a top view of the cable assemblies, with the arm structure 50 supported in the middle horizontal position (same as in FIG. 1).

[0072] FIG. 3A shows the pull cable 68 and resistance cable 30 assemblies respectively in solid lines, with the support arm structure 50 shown in phantom lines. Here the handles 90a, 90b are in an initial position, each located at the respective left and right ends 13a, 13b of the rod 12, respectively. The weight stack is at rest.

[0073] FIG. 3B is similar to FIG. 3A but now shows the right handle 90b being extended away from the machine 10, i.e., being pulled by the user (not shown) in a generally leftward direction (arrow A4), causing the right sliding bracket 60b to slide toward the left end of 13a the rod 12. The arrows A4 illustrate the respective motions of the pull cable 80 and the resistance cable 31 over the respective pulleys.

[0074] FIG. 3C is a mirror image of FIG. 3B, showing the effect of pulling on the left handle 90a, and the respective movements (arrows A5) of the pull cable 80 and resistance cable 31 over the pulleys.

[0075] FIG. 4 is a side elevational view of the apparatus of FIG. 1 showing in solid lines the pivot arm structure 50 in the horizontal middle position (in plane P50). FIG. 4 shows in phantom lines the rod 12 in an uppermost position, wherein the handle bracket is disposed near the top end of the vertical frame 11, and in an opposing lowermost position in which the rod 12 is disposed near the lowermost end of the frame (near the base member 14). The base 14 sits generally horizontal and adjacent to the ground plane P2, and the central support column 22 is vertically disposed above the base 14. Trusses 19a and 19b rigidly support the central support column 22 in an upright vertical position with respect to the base 14. About half-way up the vertical support 22, the pivot arm structure 50 is disposed at a height H1 in the horizontal plane P50. The right pulley housing 71b and handle 90b are in a relaxed position extending vertically downward, from the plane P50.

[0076] The arm structure 50 is pivotally mounted to the upright frame 11 by rotable joints 156 (see FIGS. 1, 4 and 5). A releasable pin 168 is positionable in one of a series of user selectable apertures 171 disposed about the radius of a support plate 170 of the height adjustment assembly 160 for selectively adjusting and positioning the longitudinal axis LA of the rod 12 in any one of a plurality of fixed vertically variable (height) positions relative to a ground surface plane P2. As shown, FIG. 4, the longitudinal axis LA of rod 12 can be selectively fixed at any one of a plurality of different vertical distances or heights including middle H1, uppermost H2 and lowermost H3 positions, relative to the ground plane P2. The rod 12 can be fixed at many other heights (varying vertical distances) above the ground plane P2 depending on the predetermined number and location of fixing apertures 171 provided on the pivot or height adjustment assembly 160. The apertures define the multiple pivotable positions of the support arm structure 50 on the upright frame 11.

[0077] FIG. 5 shows a top view of the apparatus of FIG. 1 in use wherein a user (not shown) is pulling on the right handle assembly 60b. The right handle bracket 60b is shown sliding across the rod 12 to the left, as previously described. The pull cable 80 extends from the right handle 90b, through the right handle bracket 60b, across a portion of the rod 12, into the left handle bracket 60a and ending at the left handle 90a. The resistance cable 31 extends from the right handle bracket 60b around the right front side pulley wheel 35b, around the right rear side pulley wheel 36b, around the right central pulley wheels 37b-38b, and into the central housing 23 (where it further extends around the common wheel 42, not shown) before exiting from the central housing 23 and extending over the left central pulley wheels 37a-38a, the left rear side wheel 36a, the left front side wheel 35a, and terminating at the left handle bracket 60a. The resistance pulley wheels are mounted in respective housings fixed to the pivot arm structure 50. The upper and lower central pulley wheels 37-38 are mounted to a transverse arm 56 extending between the side arms 52a, 52b of the pivot structure 50, with the resistance cable 31 disposed in a bore of the transverse arm 56. A pair of counterweights 55a, 55b are attached to a rear transverse arm 51 of the pivot arm structure for counterbalancing the pivot arm structure 50. A pair of diagonally disposed trusses 20a, 20b extending from the vertical support structure 22 support the transverse arm 56 and rotatable joints 156.

[0078] FIG. 5 also shows in greater detail the adjustment mechanism 160 for varying the pivot position of the arm structure 50. A user (not shown) engages a finger lever 162 at one end of an adjustment cable 163, the cable 163 extending through a central bore of the right support arm 52b and over a pulley wheel 165 mounted in the right end of transverse arm 56; the other end of the adjustment cable 163 is attached to a pin 168 for releasable insertion into one of the apertures 171 in the support plate 170, for selecting (fixing) the respective pivot position of the arm structure 50.

[0079] FIG. 6 is a fragmentary detailed perspective view of the left handle assembly 60a in use. When a user (not shown) pulls on the left handle 90a (not shown) connected to pull cable 80 in the direction of the arrow A10, the pull cable 80 rotates about pulley wheel 76a and is extended further from pulley housing 71a of the left handle bracket 60a. The housing 71a includes two spaced apart parallel plates between which is defined a cavity 72a in which the pulley wheel 76a resides; the wheel is free to rotate in the cavity, being rotatably mounted between the opposing plates by a pin 75a. The housing has an open end 74a from which the pull cable 80 extends, and an opposing second end 73a attached to the slidable tube or sleeve 62a of the left handle bracket 60a. The tube or sleeve 62a has a central bore 63a which is slidable over rod 12, as shown by the arrows. The tube or sleeve 62a is mounted on rod 12 by a bearing assembly 110a which is illustrated in FIGS. 7-8. Mounted on one end of the tube 62a is a tabbed collar 130a; the collar includes a tubular collar portion 131a concentrically disposed over and around the tube 62a (or an inwardly disposed distal tubular end 132a of the tube 62a), and a transverse arm 134a extending radially from the collar portion 131a and having at its opposing end a threaded connector 138a that secures the first distal end 33 of resistance cable 31 to the tube 62a/collar 130a. A snap ring 147a and washer 146a secure the collar 130a to the end of the tube 62a. The collar 130a is freely rotatably mounted on and around the slidable tube 62a and bracket 60a. Thus, both the bracket 60a and the collar 130a are freely rotatably mounted on and around the rod 12 for free rotation around the axis LA (see arrows A11), the bracket 60a and collar 130a being independently freely rotatable around each other and the rod 12 axis LA. Also extending from tube 62a is a curved arm 101a having at its opposing end a counterweight 100a for counterbalancing the weight of the pulley housing 71a, pulley wheel 76a and handle 90a. This ensures that both pull cable 80 and resistance cable 31 lie in planes substantially parallel to rod 12 (e.g., in plane P50 in the middle position).

[0080] As previously described, the left side support arm 52a has, adjacent its front end, a housing 39a for mounting the left front pulley wheel 35a, and a pair of aligned apertures 58a, through which the resistance cable 31 extends in parallel alignment with rod 12. As a result, when a user pulls on the left handle 90a, the pull cable 80 extends forwardly away from the frame 11, typically in a forwardly and rightwardly direction (see arrow A10), causing the pull cable 80 to rotate counterclockwise about wheel 75a, pulling the sliding tube 62a and the attached resistance cable 31 to the right (arrow A12) along rod 12, to the extent the user's pull force can overcome the resistance set by the weight stack 150 to which the resistance cable 31 is attached.

[0081] FIG. 7 is a more detailed internal view of the left handle assembly of FIG. 6, taken along lines 7-7, showing a cross section of the slidable tube 62a, tabbed collar 130a and a bearing assembly 110a for mounting tube 62a on rod 12. As shown and described below, the handle bracket 60a and slidable tube 62a are assembled together with the collar 130a in a manner such that the bracket 60a/tube 62a and collar 130a are each rotatable independently of each other (arrow A13) for free rotation around the longitudinal axis LA of the rod 12. The bearing assembly includes a pair of left and right bearing sleeves 112a, 112a concentrically disposed about axis LA and on either side of a hollow cylindrical spacer 114a; together the sleeves and spacer are secured within the central bore 63a of tube 62a, enabling the tube 62a to slide on the outer surface of rod 12 in both the left and right directions. A bearing retainer 118a and washer 116a are provided at each opposing end of the tube 62a for securing the bearing assembly within the tube bore 63a. This same bearing assembly is further illustrated in the exploded perspective view of FIG. 8.

[0082] As further illustrated in FIGS. 7-8, the collar 130a includes a tubular collar portion 131a which is secured to the outer circumference of the tubular end 132a of tube 62a at one distal end 65a thereof, the collar being secured to the tube by a washer 146a and snap ring 147a such that the collar 130a and the bracket 60a/tube 62a are longitudinally fixedly attached to each other and forced to travel or slide longitudinally along the axis LA together with each other. Extending transverse to the collar portion 131a is an arm or tab 134a having at its free end an aperture 136a through which the resistance cable 31 extends, and an adjacent threaded portion 138a which secures the first end 33 of resistance cable 31 to the left handle bracket 60a. As previously described the handle bracket assembly 60a maintains both the pull cable 80 and resistance cable 31 in substantially parallel alignment with the rod 12 during use.

[0083] In an alternative embodiment shown in FIG. 7A, the collar 130a on which the resistance cable 31 is mounted and the bracket 60a to which the handle pulley 76a is attached can alternatively be configured such that the collar 130a is mounted directly on the outside surface of the rod 12 via bearings that enable the collar 130a to rotate freely around and on the surface of the rod 12. In such an embodiment, the sleeve or bracket 60a is preferably rotatably mounted on an outside surface of a tubular element of the collar 130a such that the bracket 60a is rotatable independently and freely around and on the collar 130a.

[0084] FIGS. 9-11 show three schematic cross-sectional views of the left handle bracket assembly taken along line 9-9 of FIG. 7, with the left support arm 52a in three different positions. FIG. 9 shown the support arm 52a in a middle position (in horizontal plane P50). The rod 12 is shown in cross section within the bore of the bearing sleeve 112a; the bearing sleeve lies concentrically within the bore of tube 62a. The bearing sleeve and tube can rotate clockwise and counterclockwise about the rod 12. One end 33 of the resistance cable 31 is anchored to the arm 134a of 130a. The counterweight 100a on arm 101a counterbalances the bracket housing 71a and pulley wheel 76a, about which the pull cable 80 rotates.

[0085] In FIG. 10, the left support arm 52a has been rotated counterclockwise (see arrow A14, with respect to the position shown in FIG. 9) to a lower position, such that rod 12 now lies in a horizontal plane closer to the ground surface 2. In this position, a user will pull upwardly on pull cable 80 (see FIG. 2B). The left handle 90a (not shown) accommodates this upward pulling motion by pulley wheel 76a and pulley housing 71a being rotated clockwise (arrow 15) about rod 12. As a result, the counterweight 100a is now shown at a lower position (closer to ground plane P2), below the horizontal plane in which rod 12 resides.

[0086] Similarly, FIG. 11 shows the left support arm 52a rotated clockwise (arrow A16) in the opposite direction, placing rod 12 in a higher position. Now, a user pulls downwardly on pull cable 80, causing the pulley wheel 67a and pulley housing 71a to rotate counterclockwise (arrow A17) about rod 12. As a result, the counterweight 100a is now positioned above the horizontal plane in which rod 12 resides.

[0087] While specific embodiments of the present invention have been shown and described, it will be apparent that many modifications can be made thereto without departing from the scope of the invention. Accordingly, the invention is not limited by the foregoing description.