Abstract:
An adjustable weight-loaded dip-chin machine. Dip bars and chin bars with means for vertical adjustment are mounted on columns, which in turn are mounted on a base. An arm is pivotally attached to the base, and weights can be added to an arm spindle attached to the arm. A belt is attached to the arm, and the weighted arm spindle resist upward exerciser motion when performing dips or chins. A pivot hook releasably engages the arm spindle in an elevated position for convenience and safety when commencing and ending a squat exercise series. Means are disclosed for adjusting the height of the pivot hook on a column, and for automatically disengaging the pivot hook from the arm spindle when exercise commences. A squat platform is sized to fit between foot platforms, which together form a stable standing area for the exerciser. Squat handles are height-adjustably mounted to the columns.

Description:
CLAIM FOR PRIORITY 
     This application based on, and is a continuation-in-part, of U.S. patent application Ser. No. 11/811,920 filed Jun. 11, 2007, now U.S. Pat. No. 7,871,360 and of U.S. patent application Ser. No. 12/156,487 filed Jun. 2, 2008, now U.S. Pat. No. 7,918,770 and claims the benefit of the earlier filing date of these applications. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to exercise machines, and in particular to an adjustable weight-loaded dip-chin machine. 
     2. Background of the Invention 
     The dip-chin machine is one of the most important exercise machine available. This machine uses the resistance of one&#39;s own body to work the biceps, forearms, lateral muscles, triceps, chest, and shoulder muscles. Bars are provided for both dips and chins (also known as “chin-ups”). 
     Dips are performed by pushing oneself above the level of a pair of parallel dip bars located approximately shoulder-width apart. The exerciser grasps a dip bar with each hand, then lowers his or her body until elbows are bent and shoulders mildly stretched. The arms are used to push the exerciser upwards to the starting position. Leaning the body forward with elbows kept in works the chest muscles more. Keeping the body straight vertically with elbows close to the body works the triceps more. More strenuous dips can be accomplished by not permitting the exerciser&#39;s feet to touch the floor at all during the course of the exercise. 
     Chins are performed by pulling oneself upwards above a pair of roughly co-linear chin bars, grasping one bar with each hand. The chin bars are located above the shoulder height of the exerciser. The exerciser begins by grasping a chin bar with each hand, with palms facing the exerciser. The exerciser then pulls himself or herself upwards until either chin or chest touches the chin bars. The exerciser then slowly lowers himself or herself back to the standing position from which the chin exercise was initiated. Chin exercises strengthen the biceps, forearms, and lateral muscles. 
     One problem associated with current dip-chin machines is the inability to hook an arm bearing a weighted spindle in an elevated position, so that an exerciser may commence a squat series from a relatively erect position, and go as low as desired during subsequent squats. It would also be desirable to provide means to automatically release a hook holding the arm elevated when exercise commences. 
     Another problem with currently existing dip-chin machines is the absence of a solid platform to stand on, which is capable of accommodating different sized exercisers. The best foot support currently available is a pair of widely-spaced-apart foot supports, with a void in between which the exerciser could fall or slip into. 
     Still another problem associated with current dip-chin machines is the absence of an easily height-adjustable pair of squat handles, to aid in the squat exercise series. 
     Another problem associated with existing dip-chin machines is the lack of adjustability, either vertically or horizontally, of the dip bars and chin bars. This renders exercise difficult for non-standard sized exercisers. In addition, it would be desirable to vary the positions of the dip bars and chin bars in order to adjust the strenuousness of the dips and chins being performed, and to allow the exerciser to use the machine from an initial position standing either on the ground or on foot supports. This flexibility of use is not attainable unless the dip bars and chin bars are rendered adjustable on the dip-chin machine. 
     Still another problem associated with currently available dip-chin machines is the inability to add resistance acting against the exerciser&#39;s upward motion during dips and chins, thereby rendering the exercise more strenuous. Currently available dip-chin machines are either not weightable, or provide means to use weights to aid the exerciser during the exercise, thus rendering the exercise less strenuous. Thus, in order to make the dips and chins more strenuous it would be desirable to provide means of adding weight against the exercise being performed, not in aid of the exercise. In addition, it would be desirable to provide means for using elastic to work against the exercise, thus increasing the exercise value. 
     One currently available option is for the exerciser to wear a weight belt, from which weights dangle. While these weights have the effect of increasing the weight of the exerciser, and hence the strenuousness of the exercise, the procedure can be dangerous if the weights swing into the exerciser&#39;s limb(s), or if the exerciser were to slip off of the elevated foot support(s) and the heavy weights land on the exerciser&#39;s feet or other body part. Thus, it would be desirable to provide a safe way to add weight against the dip or chin being performed. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is an object of this invention to provide an adjustable weight-loaded dip-chin machine to which provides a stable standing area for the exerciser. Design features enabling the accomplishment of this object include a squat platform having substantially the same height as a pair of foot supports. Advantages associated with the realization of this object include increased stability and safety to exercisers using the machine. 
     It is another object of this invention to provide an adjustable weight-loaded dip-chin machine which provides an automatically-releasing means to hold its arm in an elevated position. Design features enabling the accomplishment of this object include a pivot hook rotatably attached to a column. Advantages associated with the realization of this object include increased ease of use and safety to exercisers using the machine, because exercisers can set the amount of weights desired, attach a belt line hook to the arm while the arm is elevated, raise the arm by standing up out of the mild squat required to attach the belt line hook to the arm, and then during subsequent exercise squat as low as desired. 
     It is yet another object of this invention to provide an adjustable weight-loaded dip-chin machine with variable-height squat handles. Design features allowing this object to be achieved include squat handles sized to removably fit into column apertures. Benefits associated with reaching this objective include increased convenience and effectiveness of squat exercises. 
     It is another object of the present invention to provide an adjustable weight-loaded dip-chin machine which provides a varying amount of weight which the exerciser can add acting against the dip or chin being performed. Design features allowing this object to be accomplished include an arm pivotally attached to a frame, an arm spindle on the arm, and weights sized to fit onto the arm spindle. Advantages associated with the accomplishment of this object include the ability to adjust the intensity of dips and chins being performed, and the consequent enhancement of the exercise experience to the exerciser. 
     It is another object of the present invention to provide an adjustable weight-loaded dip-chin machine which provides a varying amount of resistance which the exerciser can add acting against the dip or chin being performed. Design features allowing this object to be accomplished include an arm pivotally attached to a frame, at least one pin attached to the frame, and an elastic band connecting a pin with the arm spindle, and/or an elastic band connecting a pin with a belt worn by the exerciser, and/or weights depending from the belt worn by the exerciser. Advantages associated with the accomplishment of this object include the ability to adjust the intensity of dips and chins being performed, and the consequent enhancement of the exercise experience to the exerciser. 
     It is still another object of this invention to provide an adjustable weight-loaded dip-chin machine to which weights and force which resist the dips and chins being performed may be added safely. Design features enabling the accomplishment of this object include an arm pivotally attached to a frame, an arm spindle attached to the arm, weights which may be removably installed on the arm spindle, and a belt worn by the exerciser attached to the arm by means of a belt line. Advantages associated with the realization of this object include elimination of the necessity for an exerciser to climb up onto elevated foot supports bearing heavy weights dangling from a weight belt, and elimination of the possibility of injury to the exerciser from these weights. 
     It is still another object of this invention to provide an adjustable weight-loaded dip-chin machine to which provides varying distances between dip bar and belt attach points. Design features enabling the accomplishment of this object include an arm pivotally attached to a frame, an arm extension rigidly attached to and end of the arm opposite the frame, and dip bars attached to the frame, each having a plurality of legs spaced at differing distances from each other. Advantages associated with the realization of this object include the ability to accommodate varying sizes of exercisers using the machine. 
     It is yet another object of this invention to provide an adjustable weight-loaded dip-chin machine which is inexpensive to manufacture. Design features allowing this object to be achieved include the use of components made of readily available materials, and the use of existing weights which may be removably added to an arm spindle. Benefits associated with reaching this objective include reduced cost, and hence increased availability. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention, together with the other objects, features, aspects and advantages thereof will be more clearly understood from the following in conjunction with the accompanying drawings. 
       Sixteen sheets of drawings are provided. Sheet one contains  FIG. 1 . Sheet two contains  FIG. 2 . Sheet three contains  FIG. 3 . Sheet four contains  FIGS. 4 and 5 . Sheet five contains  FIGS. 6 and 7 . Sheet six contains  FIGS. 8 and 9 . Sheet seven contains  FIGS. 10 and 11 . Sheet eight contains  FIG. 12 . Sheet nine contains  FIG. 13 . Sheet ten contains  FIG. 14 . Sheet eleven contains  FIG. 15 . Sheet twelve contains  FIG. 16 . Sheet thirteen contains  FIGS. 17 and 18 . Sheet fourteen contains  FIG. 19 . Sheet fifteen contains  FIGS. 20 and 21 . Sheet sixteen contains  FIGS. 22 and 23 . 
         FIG. 1  is a right quarter side isometric view of an adjustable weight-loaded dip-chin machine. 
         FIG. 2  is a right side view of an adjustable weight-loaded dip-chin machine with its arm in the resting position. 
         FIG. 3  is a right side view of an adjustable weight-loaded dip-chin machine with its arm in the elevated position. 
         FIGS. 4-6  depict a dip bar bracket being installed on a column. 
         FIG. 7  is a top view of pair of dip bars mounted to respective columns  16 , showing a provision of the instant invention to accommodate different sized exercisers by varying the distance between the two dip bars. 
         FIGS. 8-10  depict a chin bar bracket being installed on a column. 
         FIG. 11  is a top view of a pair of chin bars  28  mounted to respective columns  16 . 
         FIG. 12  is a right quarter side isometric view of an alternate embodiment adjustable weight-loaded dip-chin machine incorporating a weight stack. 
         FIG. 13  is a right quarter side isometric view of an alternate embodiment adjustable weight-loaded dip-chin machine incorporating an arm extension. 
         FIG. 14  is a right side cross-sectional view, taken at section XIV-XIV of  FIG. 13 , of an alternate embodiment adjustable weight-loaded dip-chin machine incorporating an arm extension, with its arm in the resting position. 
         FIG. 15  is a right quarter side isometric view of an adjustable weight-loaded dip-chin machine incorporating a squat platform, pivot hook, and squat handles, with its arm in the resting position. 
         FIG. 16  is a right quarter side isometric view of an adjustable weight-loaded dip-chin machine incorporating a squat platform, pivot hook, and squat handles, with its arm being held in the elevated position by the pivot hook. 
         FIG. 17  is a lower end view of a squat platform. 
         FIG. 18  is an end view of a squat platform. 
         FIG. 19  is a right quarter side isometric view of a pivot hook. 
         FIG. 20  is a right quarter side isometric view of a pivot hook about to be rotatably installed on a column. 
         FIG. 21  is a right quarter side isometric view of a pivot hook pivotally installed on a column, at a right angle to the column. 
         FIG. 22  is a right quarter side isometric view of a pivot hook pivotally installed on a column, hanging downwards parallel to the column as urged by gravity. 
         FIG. 23  is a right quarter side isometric view of a squat handle. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to  FIG. 1  we observe a right quarter side isometric view of adjustable dip-chin machine  2 . Frame  1  is supported by base  3 , and arm  10  is pivotally attached to frame  1  at arm pivot point  9 . Arm  10  incorporates arm spindle  11 , to which weights  15  may be removably attached. It is contemplated to fall within the scope of this invention that arm  10  may be pivotally attached to base  3 , or pivotally attached to frame  1 . Even if arm  10  is pivotally attached to frame  1 , frame  1  is attached to base  3 , so in this case it can fairly be said that arm  10  is pivotally mounted to base  3  by means of frame  1 . 
     Frame  1  includes a pair of columns  16 . Each column  16  has a dip bar  26  and/or a chin bar  28  adjustably attached to it. Thus, the instant invention teaches that each dip bar  26  and chin bar  28  may be adjusted along the height of a respective column  16 , thereby rendering the instant adjustable dip-chin machine  2  the correct size for different exercisers, and also permitting the strenuousness of the exercises being performed to be varied. 
     Base  3  includes a pair of foot supports  5 , which are elevated relative to a surface upon which adjustable dip-chin machine  2  rests. Thus, an exerciser using adjustable dip-chin machine  2  may stand on foot supports  5 , or the surface upon which adjustable dip-chin machine  2  rests, while performing dips and/or chins. 
     In the preferred embodiment frame  1  comprised a pair of substantially parallel vertical columns  16 , each supported by a column brace  20  extending from a respective column  16  to a rear portion of base  3 . A rear extreme of arm  10  was pivotally attached to column braces  20 . A forward portion of arm  10  rested on arm support  8 , which extended horizontally between columns  16 . Arm  10  comprised a pair of arm braces  12 , one end of each arm brace  12  was rotatably attached to a respective column brace  20  at an arm pivot point  9 , opposite ends of the arm braces were mutually attached, and arm ring  14  was attached to the end of the arm braces  12  opposite column braces  20 . Each column  16  comprised a pair of opposed column faces  66  and column sides  68 . A plurality of column apertures  18  were disposed in one column side  68 , whereby the height of dip bar  26  and chin bar  28  could be adjusted. 
     In the preferred embodiment, base  3  included a pair of substantially parallel legs  4  extending from the rear to the front of adjustable dip-chin machine  2 . Each leg  4  was supported at each end by a foot  6 , and a foot support  5  was disposed atop each leg  4  forward of a column  16 . At least one peg  22  was attached to base  3 , in the preferred embodiment to leg  4  and/or foot support  5 , to which elastic band(s)  24  could be attached to a belt  30  worn by the exerciser, and/or to arm spindle  11 . Depending on the number and elasticity of elastic bands  24  connecting belt  30  and/or arm spindle  11  to pegs  22 , the strenuousness of the exercise could be varied. 
       FIG. 2  is a right side view of adjustable dip-chin machine  2  with its arm  10  in the resting position on arm support  8 .  FIG. 3  is a right side view of adjustable dip-chin machine  2  with its arm  10  in the elevated position. As may be observed in these figures, belt  30  (fastened around the waist of an exerciser, not shown) is attached to arm  10  by belt line  32 , at arm ring  14 . As an exerciser moves upwards while performing a dip or chin, so also does belt  30 , and arm  10  as indicated by arrow  34  in  FIG. 3 , because belt  30  is attached to arm  10  by means of belt line  32 . 
     Arm  10  may be weighted down by a variable number of weights  15  on arm spindle  11 , as desired by the exerciser or the trainer. In addition, one or more elastic bands  24  may be placed around arm spindle  11  and peg(s)  22  attached to frame  1 , and one or more elastic bands  24  can attach belt  30  and peg(s)  22 , as depicted in  FIGS. 2 and 3 . Finally, belt weight  36  such as chain or other appropriate weight may be attached to belt  30 , as shown in  FIG. 3 . Weights  15 , elastic bands  24 , and chain  36  exert force against the exerciser&#39;s upward motion while performing dips and chins, thus increasing the strenuousness of these exercises as desired by the exerciser and/or the trainer. 
     An important feature of the instant invention is the vertical adjustability of dip bars  26  along columns  16 .  FIGS. 4-6  depict a dip bar  26  bracket  40  being installed on a column  16 . Bracket  40  comprises bracket first leg  44  attached along one edge of bracket spine  42 , and bracket second leg  46  attached along an opposite edge of bracket spine  42 . Bracket first leg  44 , bracket spine  42 , and bracket second leg  46  define bracket aperture  50 , sized to admit column  16 . 
     Bracket second leg  46  comprises bracket second leg extension  48 , to which bracket pin  52  is rigidly attached. Each column  16  comprises a plurality of column apertures  18  sized to slidably admit bracket pin  52 . 
     Bracket  40  is installed on column  16  by first inserting bracket pin  52  into a column aperture  18  at the desired height on column  16 , as indicated by arrow  38  in  FIG. 4 . After bracket pin  52  is inserted in a column aperture  18  as depicted in  FIG. 5 , bracket  40  is rotated down around bracket pin  52  as indicated by arrow  70  in  FIG. 6  until column  16  is disposed within bracket aperture  50 , as depicted in  FIGS. 6 and 7 . 
     Bracket  40  may be re-positioned on column  16  by merely reversing the above steps, and then re-installing bracket  40  on column  16  using a different column aperture  18 , as desired. 
     As illustrated in  FIG. 5 , in the preferred embodiment bracket aperture width  54  was substantially equal to or greater than column width  56 , thus permitting column  16  to fit into bracket aperture  50 . In addition, in the preferred embodiment bracket second leg extension depth  58  was substantially equal to column depth  60 , thus permitting bracket pin  52  to fit into column aperture  18 . 
     Another way of describing the dimensional relationship between bracket pin  52  on bracket  40  relative to column apertures  18  on column  16  is depicted in  FIG. 9 , which illustrates that bracket pin offset  64  (from bracket spine  42 ) is equal to or greater than column aperture offset  62  (from column face  66 ), thus affording bracket pin  52  the offset clearance required for it to slide into a column aperture  18 . 
       FIG. 7  is a top view of a pair of dip bars  26 , each mounted to a respective column  16 , showing a provision of the instant invention to accommodate different sized exercisers by varying the distance from the other dip bar  26 . In the embodiment depicted in  FIG. 7 , each dip bar  26  comprised a dip bar first leg  61 , a dip bar second leg  63  spaced farther away from the other dip bar  26  than dip bar first leg  61 , and a dip bar third leg  65 , spaced farther away from the other dip bar  26  than dip bar second leg  63 . As may be observed in  FIG. 7 , the farther the exerciser moves from columns  16 , the farther apart dip bars  26  are spaced. The exerciser has merely to choose the dip bar  26  separation best suited for the dips being performed. 
       FIGS. 8-10  depict a chin bar  28  bracket  40  being installed on a column  16 . The apparatus and method of installation are the same as for bracket  40  with dip bar  26  attached as described above. Bracket  40  is installed on column  16  by first inserting bracket pin  52  into a column aperture  18  at the desired height on column  16 , as indicated by arrow  74  in  FIG. 8 . After bracket pin  52  is inserted in a column aperture  18  as depicted in  FIG. 9 , bracket  40  is rotated down around bracket pin  52  as indicated by arrow  72  in  FIG. 10  until column  16  is disposed within bracket aperture  50 , as depicted in  FIGS. 10 and 11 . 
     Bracket  40  may be re-positioned on column  16  by merely reversing the above steps, and then re-installing bracket  40  on column  16  using a different column aperture  18 , as desired. 
       FIG. 11  is a top view of a pair of chin bars  28  mounted to respective columns  16  using brackets  40 . Chin bar  28  is attached to, and offset from, bracket  40  by means of chin bar support  33 . Chin bar support  33  serves to offset chin bar  28  away from column  16  in the direction of the exerciser, thus rendering use of the instant adjustable dip-chin machine more ergonomic and user-friendly. 
     Referring now also to  FIG. 1 , each chin bar comprises down-sloping chin bar dogleg  29  attached to chin bar  28  at chin bar dogleg angle  31 . The down slope of chin bar dogleg  29  renders chin bar  28  easier to use because it serves to effectively vary the distance between the exerciser and chin bar  28 : the farther from columns  16 , the lower chin bar dogleg  29  slopes. It was determined experimentally that a chin bar dogleg angle  31  substantially between 5 degrees and 25 degrees was optimal. 
       FIG. 12  is a right quarter side isometric view of an alternate embodiment adjustable dip-chin machine  2  incorporating weight stack  80 . Weight stack  80  comprises a plurality of stack weights  82  sliding on weight guides  84 . The placement of stack pin  86  determines the amount of stack weights  82  which will be connected to cable  90 . Cable  90  is attached to weight stack  80 , then is routed through pulleys  88  attached to frame  1  and base  3 , and finally attaches to belt  30 . 
     When an exerciser wearing belt  30  moves upwards while performing a dip or chin, belt  30  pulls cable  90 , which in turn raises a number of stack weights  82  determined by the placement of stack pin  86 . In this embodiment of adjustable dip-chin machine  2 , the exerciser and/or trainer determine an appropriate amount of weight to be added for the exercise, stack pin  86  is set accordingly, and then the exerciser performs the dips and/or chins, these exercises being rendered appropriately more strenuous by the addition of weight from weight stack  80 . 
     In addition, as in the preferred embodiment of adjustable dip-chin machine  2  previously described, one or more elastic bands can attach belt  30  to base  3 , and chain  36  or other appropriate weight may be attached to belt  30 . Weight stack  80 , elastic bands  24 , and chain  36  exert force against the exerciser&#39;s upward motion while performing dips and chins, thus increasing the strenuousness of these exercises as desired by the exerciser and/or the trainer. 
     Weight stacks  80  are old and well-known in the industry. Thus, although the particular weight stack  80  depicted in  FIG. 12  shows stack weights  82  selected by stack pin  86  sliding on weight guides  84 , it is intended to fall within the scope of this invention that any weight stack configuration known in the art may be used to supply downward force to belt  30 , as described above. 
       FIG. 13  is a right quarter side isometric view of an alternate embodiment adjustable dip-chin machine  2  incorporating arm extension  92  rigidly attached to an end of arm  10  opposite column braces  20 .  FIG. 14  is a right side cross-sectional view, taken at section XIV-XIV of  FIG. 13 , of an alternate embodiment adjustable dip-chin machine  2  incorporating arm extension  10 , with arm  10  in the resting position. 
     In this alternate embodiment of adjustable dip-chin machine  2 , arm extension  92  incorporates a plurality of arm extension apertures  94  sized to admit belt line hook  96 . In use, the user inserts belt link hook  96  into the most comfortable arm extension aperture  94 , then proceeds with exercising. As previously mentioned, differently-sized exercisers may be accommodated by varying their distance from the other dip bar  26 . In the embodiment depicted in  FIG. 7 , each dip bar  26  comprised a dip bar first leg  61 , a dip bar second leg  63  spaced farther away from the other dip bar  26  than dip bar first leg  61 , and a dip bar third leg  65 , spaced farther away from the other dip bar  26  than dip bar second leg  63 . As may be observed in  FIG. 7 , the farther the exerciser moves from columns  16 , the farther apart dip bars  26  are spaced. The exerciser has merely to choose the dip bar  26  separation best suited for the dips being performed. 
     Thus, the distance of an exerciser from columns  16  may vary, and the exerciser&#39;s position along foot supports  5  may vary. Depending on the distance of the exerciser from columns  16 , the exerciser may wish to change the attached point of belt line  32  along arm extension  92 , after donning belt  30  for exercise using the instant invention as described previously. The exerciser accomplishes this objective by inserting belt line hook  96  into the arm extension aperture  94  which is most comfortable and appropriate in view of the exerciser&#39;s distance from columns  16 , as indicated by arrows  98 . 
     Referring now to  FIG. 15  we observe a right quarter side isometric view of adjustable weight-loaded dip-chin machine  2  incorporating squat platform  100 , pivot hook  120 , and squat handles  140 , with arm  10  in the resting position on arm support  8 .  FIG. 16  is a right quarter side isometric view of adjustable weight-loaded dip-chin machine  2  incorporating squat platform  100 , pivot hook  120 , and squat handles  140 , with its arm  10  being held in the elevated position by pivot hook  120 . 
       FIG. 17  is a lower end view of squat platform  100 .  FIG. 18  is an end view of squat platform  100 . 
     As may be observed in these figures, squat platform  100  comprises platform deck  102  supported along opposite edges by platform sides  112 . Platform groove  104  in platform deck  102  is sized to admit arm extension  92  when arm  10  is resting on arm support  8  in the resting position. 
     Squat platform  100  further comprises a platform side foot  108  attached to each platform side  112  along an edge of each platform side  112  opposite platform deck  102 . Platform anti-slip pads  110  are attached to the undersides of each platform side foot  108 , and serve to help hold squat platform  100  in position. 
     Squat platform  100  further comprises a platform center foot  106  for additional support and stability. 
     As may be observed in  FIG. 18 , the sum of platform side height  116  and platform anti-slip pad height  118  is substantially equal to platform height  114 . As a result of this dimensionality, platform anti-slip pads  110  and platform center foot  106  all rest upon the floor, not only producing an extremely well-supported and stable platform deck  102 , but also preventing squat platform  100  from sliding around, because part of its weight is supported by platform anti-slip pads  110 . 
     Squat platform  100  may be inserted between foot supports  5  for use, as indicated by arrow  101  in  FIG. 15 , into the position depicted in  FIG. 16 . As may be noted, squat platform height  114  is substantially equal to foot support height  7 . Platform anti-slip pads  110  help hold squat platform  100  securely in position between foot supports  5 . 
     Thus, when squat platform  100  is emplaced between foot supports  5  as depicted in  FIG. 16 , platform deck  102  in combination with foot supports  5  produce a flat surface for the exerciser to stand on, interrupted only by platform groove  104  and the narrow gaps between squat platform  100  and foot supports  5 . This feature of the instant invention contributes greatly to the convenience, comfort, and safety of the instant invention by providing a stable, non-slip surface upon which the exerciser can stand. In addition, this feature contributes greatly to the versatility of the instant invention, because exercisers having different widths of foot prints can use the apparatus, be they large individuals, or smaller women and children. 
       FIG. 19  is a right quarter side isometric view of pivot hook  120 .  FIG. 20  is a right quarter side isometric view of pivot hook  120  about to be pivotally installed on column  16 .  FIG. 21  is a right quarter side isometric view of a pivot hook  120  pivotally installed on column  16 , at a right angle to column  16 .  FIG. 22  is a right quarter side isometric view of pivot hook  120  pivotally installed on column  16 , hanging downwards parallel to column  16  as urged by gravity. 
     Referring now to these figures, and also  FIGS. 15 and 16 , pivot hook  120  comprises pivot hook aperture  122  at one end of pivot hook arm  121 . Pivot hook aperture  122  is sized to admit arm spindle  11 . Pivot hook pin  124  and pivot hook handle  126  are attached to the end of pivot hook arm  121  opposite pivot hook aperture  122 . 
     Pivot hook  120  additionally comprises pivot hook bracket  128  attached to pivot hook arm  121  between pivot hook pin  124  and pivot hook aperture  122 . Pivot hook bracket  128  is sized to embrace column  16 , as depicted in  FIG. 22 , in order to act as a stop against rotation of pivot hook  120  relative to column  16 . 
     Pivot hook bracket  128  comprises pivot hook leg  129  rigidly attached to pivot hook bracket spine  127 . One edge of pivot hook bracket spine  127  is attached to pivot hook arm  121 ; pivot hook bracket leg  129  is attached to an edge of pivot hook bracket spine  127  opposite pivot hook arm  121 . As may be observed in  FIG. 21 , pivot hook bracket spine width  130  is substantially equal to or greater than column width  56 , in order to allow pivot hook bracket  128  to embrace column  16  as depicted in  FIG. 22 . Pivot hook arm  121 , pivot hook bracket spine  127 , and pivot hook bracket leg  129  define pivot hook bracket aperture  132 , sized to admit column  16 . 
     Pivot hook  120  serves to hold arm  10  in an elevated position such as is depicted in  FIG. 16 , so that an exerciser may conveniently attach belt line  32  to arm  10 , e.g. by inserting belt line hook  96  through an arm extension aperture  94 . Advantages in elevating arm  10  prior to so doing include increased ease of use and safety to exercisers using the machine, because exercisers can set the amount of weights desired, attach belt line  32  to arm  10  while arm  10  is elevated, raise arm  10  by standing up out of the mild squat required to attach belt line hook  96  to arm  10 , and then during subsequent exercise squat as low as desired. Following this procedure permits the first squat to be mild and easy, and subsequent squats to be as low as the exerciser wishes. 
     When the exerciser wishes to cease exercising, pivot hook  120  can be easily engaged by pulling pivot hook handle  126  towards the exerciser and lowering arm  10  until arm spindle  11  rests within pivot hook aperture  122 . This procedure is safer and less injury-prone than squatting deeply at the conclusion of the squat exercise series until arm  10  rests on arm support  8  as depicted in  FIG. 15 . 
     Because the height of pivot hook  120  may be varied according to which column aperture  18  pivot hook pin  124  is inserted, the elevated height of arm  10  may be varied as desired when arm spindle  11  is disposed within pivot hook aperture  122 , which contributes greatly to the convenience and safety of the instant invention. One reason for this is the ability to rotatably attach pivot hook  120  at a height on column  16  appropriate to the size of the individual exerciser. 
     Thus, an important feature of the instant invention is the vertical adjustability of pivot hook  120  relative to column  16 .  FIGS. 20-22  depict pivot hook  120  being installed on a column  16 , the first step of which is to insert pivot hook pin  124  into a column aperture  18  at a desired height, as indicated by arrow  138  in  FIG. 20 . Pivot hook pin  124  is sized to slidably fit into column apertures  18 . 
     After pivot hook pin  124  is inserted in a column aperture  18  as depicted in  FIG. 21 , pivot hook  120  is allowed to rotate down around pivot hook pin  124  under the influence of gravity as indicated by arrow  131  in  FIG. 22 , until column  16  is disposed within pivot hook bracket aperture  132 , as depicted in  FIG. 22 . 
     Pivot hook  120  may be re-positioned on column  16  by merely reversing the above steps, and then re-installing pivot hook  120  on column  16  using a different column aperture  18 , as desired. 
     As may be observed in  FIG. 21 , in the preferred embodiment pivot hook bracket  128  was disposed at a pivot hook bracket offset distance  134  from the end of pivot bracket arm  121  opposite pivot hook aperture  122  substantially equal to or greater than column depth  60 . This dimensional relationship avoided mechanical interference between pivot hook bracket  128  and column  16  when sliding pivot hook pin  124  into a column aperture  18 . 
     Another important feature of the instant pivot hook  120  design is its ability to automatically disengage from arm spindle  11  when arm spindle  11  is lifted. This automatic disengagement is provided by the natural force of gravity in two ways. First, as urged by gravity, pivot hook arm  121  will tend to hang vertically downwards from pivot hook pin  124 . Second, the gravity force moment acting on pivot hook arm  121  due to the pivot hook handle angle  137  between pivot hook handle  126  and the longitudinal axis of pivot hook arm  121  tends to urge pivot arm  121  to rotate down as indicated by arrow  131  in  FIG. 22 , until this rotation is stopped by pivot hook bracket  128 , and hold pivot hook bracket  128  in intimate engagement with column  16 . 
     Thus, the value of pivot arm handle angle  137 , as well as the dimensional relationship between pivot hook handle length  136  and pivot hook arm length  135 , is important to the function of automatic disengagement of pivot hook  120  from arm spindle  11 , and its subsequent retention it the stowed position shown in  FIG. 22 . In the preferred embodiment, pivot hook handle angle  137  was 40±20 degrees, and pivot hook handle length  136  was 38%±20% of pivot hook arm length  135 . 
       FIG. 23  is a right quarter side isometric view of squat handle  140 . Squat handles  140  may be installed through any column aperture  18  desired, thus providing vertical adjustability. Squat handle  140  comprises squat handle hand grip  142  rigidly attached to squat handle pin  144 . Squat handle pin  144  is sized to slidably fit into column apertures  18 . The cross-sectional area of squat handle hand grip  142  exceeded that of squat handle pin  144 , thus allowing squat handle hand grip  142  to act as a stop when squat handle pin  144  is inserted into a column aperture  18 . Squat handle pin aperture  146  sized to slidably admit safety pin  148  is disposed at an end of squat handle pin  144  opposite squat handle hand grip  144 . 
     Once squat handle pin  144  has been slid through an appropriate column aperture  18 , safety pin  48  is slid through squat handle pin aperture  146  to lock squat handle  140  in place onto column  16 . 
     In the preferred embodiment, frame  1 , base  3 , arm  10 , brackets  40 , dip bars  26 , chin bars  28 , squat platform  100 , pivot hook  120  and squat handles  140  were made of metal, synthetic, or any other appropriate material. Belt  30  was a conventional exercise weight belt. Belt line  32  and cable  90  were any appropriate elongate member, including cable, rope, synthetic, chain, etc. Chain  36  was conventional metal link chain or other appropriate chain. Weight stack  80  was a commercially available weight stack. Squat platform anti-slip pads  110  were made of rubber, synthetic, or any other appropriate anti-slip material. 
     While a preferred embodiment of the invention has been illustrated herein, it is to be understood that changes and variations may be made by those skilled in the art without departing from the spirit of the appending claims. 
     DRAWING ITEM INDEX 
     
         
           1  frame 
           2  adjustable dip-chin machine 
           3  base 
           4  leg 
           5  foot support 
           6  foot 
           7  foot support height 
           8  arm support 
           9  arm pivot point 
           10  arm 
           11  arm spindle 
           12  arm brace 
           14  arm ring 
           15  weight 
           16  column 
           18  column aperture 
           20  column brace 
           22  peg 
           24  elastic band 
           26  dip bar 
           28  chin bar 
           29  chin bar dogleg 
           30  belt 
           31  chin bar dogleg angle 
           32  belt line 
           33  chin bar support 
           34  arrow 
           36  belt weight 
           38  arrow 
           40  bracket 
           42  bracket spine 
           44  bracket first leg 
           46  bracket second leg 
           48  bracket second leg extension 
           50  bracket aperture 
           52  bracket pin 
           54  bracket aperture width 
           56  column width 
           58  bracket second leg extension depth 
           60  column depth 
           61  dip bar first leg 
           62  column aperture offset 
           63  dip bar second leg 
           64  bracket pin offset 
           65  dip bar third leg 
           66  column face 
           68  column spine 
           70  arrow 
           72  arrow 
           74  arrow 
           80  weight stack 
           82  stack weight 
           84  weight guide 
           86  stack pin 
           88  pulley 
           90  cable 
           92  arm extension 
           94  arm extension aperture 
           96  belt line hook 
           98  arrow 
           100  squat platform 
           101  arrow 
           102  platform deck 
           104  platform groove 
           106  platform center foot 
           108  platform side foot 
           110  platform anti-slip pad 
           112  platform side 
           114  platform height 
           116  platform side height 
           118  platform anti-slip pad height 
           120  pivot hook 
           121  pivot hook arm 
           122  pivot hook aperture 
           124  pivot hook pin 
           126  pivot hook handle 
           127  pivot hook bracket spine 
           128  pivot hook bracket 
           129  pivot hook bracket leg 
           130  pivot hook bracket spine width 
           131  arrow 
           132  pivot hook aperture 
           134  pivot hook bracket offset distance 
           135  pivot hook arm length 
           136  pivot hook handle length 
           137  pivot hook handle angle 
           138  arrow 
           140  squat handle 
           142  squat handle hand grip 
           144  squat handle pin 
           146  squat handle pin aperture 
           148  safety pin