Patent Publication Number: US-10307637-B2

Title: Exercise machine having horizontally extending and selectively connected weight plates

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to an exercise machine having particular application for enabling a user to exercise his biceps during an exercise routine. By applying pulling forces to a pair of handles of the machine, a user can lift a pair of weight plate carriages and one or more vertically upstanding weight plates from respective horizontally extending pluralities of weight plates that are selectively connected to the weight plate carriages. 
     2. Background Art 
     Conventional exercise machines typically include a vertical stack of weight plates positioned one on top of the other which have a set of bore holes therethrough and which are known to those in the art as a selectorized weight stack. A pair of guide rods pass through respective side bore holes to create a vertical track along which the stack of weight plates can ride. A center post passes through another bore hole at the center of the stack, and a selector pin is inserted through one of a series of pin holes formed in the center post so that a particular number of weight plates from the stack can be lifted by the user. The number of weight plates and the total weight to be lifted during any exercise will depend upon the particular pin bole along the center post into which the selector pin is inserted. A pulling force applied by the user to a cable which communicates with the center post will generate a lifting force which can be repeated a number of times to cause any number of weight plates from the stack to be lifted depending upon the location of the selector pin relative to the center post. 
     It can be appreciated that the aforementioned weight plate lifting exercise machine having a pair of guide rods to be received through the side bore holes of each weight plate will be noisy to use and have relatively high maintenance costs. That is, it will be necessary from time-to-time to clean and lubricate the guide rods to ensure that the weight plates will slide easily therealong. Moreover, the selector pin is removable from the center post of the weight plate lifting exercise machine following a workout. Consequently, the selector pin is known to be lost, stolen or damaged which can interfere with the ability to use the machine on an as-needed basis. In cases where the selector pin is not immediately available, substitutes have sometimes been used which may be functionally and/or structurally inadequate to ensure that the apparatus will be properly and safely used. 
     Accordingly, an improvement to the conventional weight plate lifting exercise machine is desirable in order to overcome the shortcomings described above by reducing noise and eliminating the requirement for a center post, the guide rods, and a selector pin to cooperate with the center post. 
     SUMMARY OF THE INVENTION 
     In general terms, an exercise machine is disclosed by which to enable a user to exercise his biceps. The machine includes a shrouded weight plate retention housing having an upstanding barrier at each side thereof. Located adjacent each upstanding barrier is an identical weight plate carriage that is adapted to lift in a vertical direction one or more vertically upstanding weight plates from a horizontally extending plurality of weight plates that are arranged in parallel side-by-side alignment with one another. The weight plates have different lengths and correspondingly different weights (e.g., from 5 to 20 pounds). A lifting cable is connected at one end thereof to the top of a weight plate carriage positioned at one side of the weight plate retention housing. The opposite end of the lifting cable is wrapped around a weight plate carriage lifting cam. A coupling rod connects the cam to a lifting arm of the exercise machine. A lifting force applied by one arm of the user to a handle end of the lifting arm during an exercise routine causes the lifting arm and the cam to rotate, whereby to impart a vertical uplifting three to the weight plate carriage by way of the lifting cable in order to lift the carriage and any of the weight plates that are selectively connected thereto. 
     A weight plate lifting block is affixed to the top of the weight plate carriage. A pair of engagement pin receiving holes are formed in the lifting block. The lifting block is received within a lifting cavity that is formed in each of the first (e.g., 5 pounds) and second (e.g., 10 pounds) weight plates from the horizontally extending plurality of weight plates. Each of the first and second weight plates has an identical locking cartridge connected at one side thereof. A user actuated control knob communicates with an engagement pin that is located within and slidable through the locking cartridge. When the user moves the control knob from an unlocked position to a locked position, the engagement pin is correspondingly pushed from a retracted position withdrawn inwardly of the locking cartridge to an extended position projecting outwardly from the locking cartridge for receipt by a respective one of the pair of engagement pin receiving holes formed in the lifting block, whereby one or both of the first and second weight plates are selectively connected to the weight plate carriage to be lifted thereby depending upon the position of the control knobs of the locking cartridges. 
     A weight plate clasp (e.g., a hook) is pivotally connected to and rotated by a torsion spring forwardly of the weight plate lifting block at the top of the weight plate carriage. A third weight plate (e.g., 20 pounds) from the horizontally extending plurality of weight plates has a hook retaining cavity formed therein in which the weight plate hook is positioned. A locking cartridge is connected to one side of the third weight plate. When a user moves a control knob from an unlocked position to a locked position, an engagement pin is correspondingly pushed outwardly from the locking cartridge and into the hook retaining cavity of the third weight plate within which to capture the hook end of the weight plate hook that is pivotally connected to the weight plate lifting block, whereby the third weight plate is connected to the weight plate carriage to be lifted thereby. 
     Each of the third and remaining weight plates (e.g., 20 pounds) from the horizontally extending plurality of weight plates has a rotatable weight plate clasp (e.g., a hook) pivotally connected thereto at the hook retaining cavity thereof to be rotated by a torsion spring into the hook retaining cavity of a succeeding weight plate. A locking cartridge is connected to one side of each of the fourth and additional ones of the weight plates. When the user moves a control knob from the locking cartridge connected to any one of these weight plates from an unlocked position to a locked position, an engagement pin is correspondingly pushed outwardly from the locking cartridge and into the hook retaining cavity of the weight plate to which the locking cartridge is connected. The engagement pin captures the hook end of the rotatable weight plate hook that is pivotally connected to the preceding (e.g., the third) weight plate, whereby the succeeding (e.g., the fourth) weight plate is selectively connected to the preceding weight plate and to the weight plate carriage so that each of the fourth and remaining weight plates can be lifted depending upon the position of the control knobs of the respective locking cartridges. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1 and 2  show an exercise machine by which a user can exercise his biceps by lifting one or more weight plates from horizontally extending pluralities of weight plates that are selectively connected to and lifted by weight plate carriages located at opposite sides of the machine; 
         FIG. 3  shows details of a weight plate carriage located at one side of the machine of  FIGS. 1 and 2  to which the weight plates front one horizontally extending plurality of weight plates are selectively connected; 
         FIG. 4  shows one weight plate carriage and the horizontally extending plurality of weight plates thereof in an at-rest position with no uplifting pulling force being applied to the carriage; 
         FIGS. 5 and 6  show the weight plate carriage of  FIG. 4  and the weight plates which have been selectively connected thereto being lifted in a vertical direction after an uplifting pulling force has been applied to the carriage; 
         FIG. 7  shows the directions in which a pair of carriage guide cables are moved when the uplifting pulling force is applied to the weight plate carriage of  FIGS. 5 and 6  to lift the carriage in the vertical direction; 
         FIG. 8  shows the weight plates from one horizontally extending plurality of weight plates positioned side-by-side one another according to a preferred embodiment of this invention; 
         FIGS. 9-11  illustrate first and second weight plates from the horizontally extending plurality of weight plates of  FIG. 8  being selectively connected to a weight plate lifting block of the weight plate carriage; 
         FIGS. 12-16  illustrate details of each of the third and succeeding weight plates from the horizontally extending plurality of weight plates of  FIG. 8 ; 
         FIG. 17  is a partial cross-section of the horizontally extending weight plates with, for example, the first, third, fourth and fifth weight plates from the plurality of weight plates being selectively coupled to the weight plate carriage when the carriage is at-rest; 
         FIG. 18  shows the weight plate carriage and the weight plates selectively connected thereto as shown in  FIG. 17  being lifted in the vertical direction in response to an uplifting pulling force being applied to the carriage; and 
         FIG. 19  shows the weight plate carriage and the weight plates selectively connected thereto as shown in  FIG. 18  being lowered after the uplifting pulling force that was previously applied to the carriage has been terminated. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     A machine  1  by which to enable a user to exercise his biceps is initially described while referring to  FIGS. 1 and 2  of the drawings. The exercise machine  1  shown in  FIGS. 1 and 2  is commonly found and used in a gym as part of a fitness and exercise routine. As will soon be explained, the exercise machine includes a pair of weight plate carriages (designated  3  in  FIG. 2 ) each of which having a plurality of (e.g., rectangular) vertically upstanding weight plates that are aligned side-by-side one after another so as to extend horizontally across the weight plate carriage. As will also be explained, the weight plates from each plurality thereof have a variety of different lengths and correspondingly different weights to be selectively lifted with the weight plate carriage  3  by which the user can adjust the total weight lifted and thereby control the intensity of the workout according to his needs and capability. 
     The exercise machine  1  includes a shrouded weight plate retention housing  4  having a pair of upstanding barriers  5  and  7  located at opposite sides of the housing  4 . Each of the upstanding barriers  5  and  7  is surrounded by a tubular steel frame member  9  running along the bottom and a tubular steel frame member  10  running continuously around the sides and top. Each upstanding barrier  5  and  7  that is surrounded by the tubular frame members  9  and  10  includes an upper shrouded section  12  and a lower shrouded section  14 . The upper and lower shrouded sections  12  and  14  of the barriers  5  and  7  are preferably manufactured from plastic or metal and provide the sides of the weight plate retention housing  4  of the exercise machine  1  with continuous walls to prevent the user&#39;s hands and arms from extending outside the housing. 
     Another tubular steel frame member  16  is located between the upstanding barriers  5  and  7  of the weight plate retention housing  4 . Standing upwardly from frame member  16  is a seat adjustment post  18 . A 4-bar linkage  20  is coupled between the seat adjustment post  18  and a padded seat  22  upon which the user of the exercise machine  1  is seated. Once a position control lever  24  is depressed, the 4-bar linkage  20  allows the elevation of the seat  22  to be adjusted according to the needs and size of the user. 
     The exercise machine  1  includes a pair of identical handles  28  to be gripped by the hands of the user wishing to lift those weight plates which are carried by the weight plate carriages  3 . Since they are identical, only one handle  28  and its interconnection with one weight plate carriage  3  at one side of the weight plate retention housing  4  will be described. As is best shown in  FIG. 2 , the handle  28  bends upwardly and outwardly from a lifting arm  30 . The lifting arm  30  extends above art elbow pad  32  that is seated upon an elbow pad support  34  that is affixed to the upstanding barrier  7  of the weight plate retention housing  4 . One elbow of the user rests upon the elbow pad  32  when the user applies a pulling farce to the handle  28  by which to lift selected ones of the weight plates that are carried by the weight plate carriage  3  at one side of housing  4  in a manner that will soon be disclosed. The lifting arm  30  is connected at one end thereof to the handle  28  and at the opposite end to a counter weight  36 . 
     A rotatable weight plate carriage lifting cam  38  is located between the upper shrouded section  12  of the upstanding barrier  7  at one side of the weight plate retention housing  4  and the lifting arm  30 . A coupling rod  40  extends outwardly from the shrouded section  12  to pass through the rotatable cam  38  and through the lifting arm  30  to which an end cap  42  is connected to establish a pivot approximately midway between the handle  28  and the counter weight  36  at opposite ends of arm  30 . The lifting arm  30  is adapted to rotate back and forth at the pivot in response to a pulling force applied by the user to the handle  28 . Inasmuch as the rotatable cam  38  is coupled to the lifting arm  30  by the coupling rod  40 , a rotation of the lifting arm  30  causes a simultaneous rotation of both the cam  38  and the coupling rod  40 . 
     A weight plate carriage lifting cable or belt  44  is connected at one end thereof to the weight plate carriage  3  and at the opposite end to the rotatable weight plate carriage lifting can  38 . Accordingly, a rotation of the rotatable cam  38  with the coupling rod  40  and the lifting arm  30  in response to a pulling force applied by the user to the handle  28  will cause a linear uplifting force to be applied to the weight plate carriage  3  by way of the cable  44  whereby to lift the weight plate carriage  3  and selected ones of the weight plates. 
     Referring to  FIG. 3  of the drawings, details are disclosed concerning the weight plate carriage  3  that is located adjacent the upstanding barrier  7  at one side of the exercise machine  1 . As indicated earlier, an identical weight plate carriage (not shown) is located at the opposite side of the exercise machine  1 . The weight plate carriage  3  includes a pair of vertical carriage alignment columns  48  and  50  running along the opposite sides thereof. Upper and lower spacing flanges  52  and  53  extend between the carriage alignment columns  48  and  50  to hold the columns in spaced parallel alignment. A top plate  54  extends across the top of the weight plate carriage  3  between the alignment columns  48  and  50 . 
     Upper and lower ball bearing loaded rollers  56  and  57  are partially recessed within and rotatably connected to the outwardly facing side of the carriage alignment column  48 . Upper and lower ball bearing loaded rollers  58  and  59  are also partially recessed within and rotatably connected to the outwardly facing side of the carriage alignment column  50 . Each of the pairs of upper and lower rollers  56 ,  57  and  58 ,  59  has a radiused guide track  60  running circumferentially therearound. The upper and lower rollers  56 - 59  are rotatably connected to the carriage alignment columns  48  and  50  of the weight plate carriage  3  by means of respective bolts (not shown) that are received by the alignment columns through bolt holes  62  formed therein. 
     Recessed partially within and affixed (e.g., welded) to one of the carriage alignment columns  50  at the top of and at one side of the weight plate carriage  3  is a weight plate lifting block  64 . The weight plate lifting block  64  holds a hook-shaped weight plate clasp  66  at the top of the weight plate carriage  3 . The weight plate clasp  66  is pivotally connected to lifting block  64  by means of a (e.g., shoulder) bolt  67  for a purpose that will soon be explained. A pair of engagement pin receiving holes  68  and  69  are formed through the lifting block  64 . 
     One end of the aforementioned weight plate carriage lifting cable  44  is connected to the rotatable weight plate carriage lifting cam ( 38  of  FIGS. 1 and 2 ). The opposite end of the lifting cable  44  is wrapped around and connected to a cable lock  70 . The cable lock  70  is affixed (e.g., welded) to the top plate  54  that extends across the top of the weight plate carriage  3 . Thus, and as was previously described when referring to  FIGS. 1 and 2 , a pulling three applied by the user of the exercise machine to the handle  28  imparts a rotation to the rotatable weight carriage lifting cam  38  which, in turn, causes a linear uplifting pulling force to be applied to the lifting cable  44 , whereby the weight plate carriage  3  and selected ones of the weight plates carried thereby are lifted as part of the user&#39;s exercise routine. 
       FIGS. 4-6  of the drawings illustrate the weight plate carriage  3  connected to one of the upstanding barriers  7  located at one side of the shrouded weight plate retention housing (designated  4  in  FIGS. 1 and 2 ) of the exercise machine  1 . The weight plate carriage  3  is shown in  FIG. 4  at-rest with no pulling force being applied to lifting cable  44 , and the weight plate carriage  3  is shown in  FIGS. 5 and 6  after being lifted in response to a pulling force applied to cable  44 . An upper carriage stabilizer plate  72  extends laterally across the upstanding barrier  7  between the frame member  10  at opposite sides thereof. A lower carriage stabilizer plate  74  is affixed (e.g., welded) to the frame member  9  at the bottom of barrier  7 . The weight carriage lifting cable  44  is connected from the cable lock  70  at the top of the weight plate carriage  3  to the weight plate carriage lifting cam  38  by way of a hole  75  formed through the upper carriage stabilizer plate  72 . 
     A first carriage stabilizer post  76  extends vertically through the upstanding barrier  7  between the upper and lower carriage stabilizer plates  72  and  74  thereof so as to lie adjacent one side of the weight plate carriage  3 . A second carriage stabilizer post  78  also extends vertically through the barrier  7  between the upper and lower carriage stabilizer plates  72  and  74  so as to lie adjacent the opposite side of the weight plate carriage  3 . The first and second carriage stabilizer posts  76  and  78  are (e.g. cylindrically) shaped to be received within the radiused guide tracks (designated  60  in  FIG. 3 ) from the pairs of upper and lower rollers  56 ,  57  and  58 ,  59  that are rotatably connected to the carriage alignment columns  48  and  50  at opposite sides of the weight plate carriage  3 . 
     A horizontal pivot support brace  79  extends laterally across the top of the upstanding barrier  7  between the frame member  10  at opposite sides of the barrier  7  so as to lie above the upper carriage stabilizer plate  72 . The previously described coupling rod  40  projects inwardly from the pivot support brace  79  of the barrier  7  to be received through the lifting arm  30  which lies above the elbow pad  32  (of  FIG. 2 ). As was earlier explained, a pivot axis is created by coupling rod  40  around which the lifting arm  30  is rotated in response to a pulling force applied by the user to the handle  28  connected to lifting arm  30 . 
     An elbow pad support bracket  80  is also affixed to the pivot support brace  79  adjacent the coupling rod  40 . An elbow pad support rod  81  projects from the elbow pad support bracket  80  to be connected to the elbow pad support  34  (of  FIG. 2 ) by which to hold the elbow pad  32  in place below the lifting arm  30  so as to withstand the pressure of the user&#39;s elbow thereupon. 
     As was also previously explained, the weight plate carriage  3  and any of a number of weight plates that are selectively coupled thereto are lifted as a unit in response to an uplifting pulling force being applied by the weight plate carriage lifting cable  44  to the cable lock  70  atop the carriage  3 . The weight plate carriage  3  is repeatedly lifted and lowered during successive exercise cycles by way of a pair of carriage guide cables  82  and  84 . First ends of the carriage guide cables  82  and  84  are connected to one another at a first eyeball tie rod hushing  86  located at one side of the weight plate carriage  3 . Opposite ends of the carriage guide cables  82  and  84  are connected to one another at a second eyeball tie rod bushing  88  located at the opposite side of the carriage  3 . 
     A pair of upper cable pulleys  90  and  91  are affixed to the upper carriage stabilizer plate  72  so as to be spaced from one another above the weight plate carriage  3 . A first pair of lower cable pulleys  92  and  93  are affixed to the tubular steel frame member  9  at the bottom of the upstanding barrier  7  so as to be spaced from one another below the weight plate carriage  3 . The upper cable pulley  90  is axially aligned with the lower cable pulley  92  at one side of the carriage  3 , and the upper cable pulley  91  is axially aligned with the lower cable pulley  93  at the opposite side of the carriage  3 . A second pair of lower cable pulleys  94  and  95  are also affixed to the frame member  9  of barrier  7  so as to be spaced from one another below the carriage  3 . However, the second pair of lower cable pulleys  94  and  95  are spaced inwardly of and slightly above the first pair of lower cable pulleys  92  and  93 . 
     The first  82  of the pair of carriage guide cables extends from the first tie rod bushing  86  located at one side of the weight plate carriage  3  to run up, over and around the upper cable pulley  90 , down and under the lower cable pulley  94  from the second pair thereof, under the lower cable pulley  93  from the first pair thereof, and up to the second tie rod bushing  88  located at the opposite side of the carriage  3 . The second  84  of the pair of carriage guide cables extends from the second tie rod bushing  88  located at the opposite side of the weight plate carriage  3  to run up, over and around the upper cable pulley  91 , down and under the lower cable pulley  95  from the second pair thereof, under the lower cable pulley  92  from the first pair thereof, and up to the first tie rod bushing  86  located at the first side of the carriage  3 . 
     The first and second eyeball tie rod bushings  86  and  88  are attached to opposite sides of the weight plate carriage  3  so as to be carried by the carriage as it moves up and down relative to the first and second carriage stabilizer posts  76  and  78  during successive exercise cycles in response to repetitive pulling forces applied by the user to the handlebars (designated  28  in  FIG. 1 ). As the weight plate carriage  3  moves up and down, the pairs of upper and lower rollers  56 ,  57  and  58 ,  59  roll over the first and second carriage stabilizer posts  76  and  78  which are fixed in place between the upper and lower carriage stabilizer plates  72  and  74 .  FIG. 7  of the drawings shows the directions in which the carriage guide cables  82  and  84  move as the weight plate carriage  3  is pulled by the weight plate carriage lifting cable  44  upwardly through the weight plate retention housing (designated  4  in  FIG. 1 ) to a lifted position shown in  FIGS. 5 and 6 . As shown by the cable matrix of  FIG. 7 , the cables  82  and  84  work against one another (i.e., move in opposite directions) to ensure that the weight plate carriage  3  will remain horizontally level and avoid shifting to one side or the other regardless of the magnitude of the weight that is lifted by the carriage. 
     Details of the individual weight plates to be lifted and carried by each weight plate carriage  3  of the exercise machine  1  herein disclosed are initially described while referring to  FIG. 8  of the drawings. As a unique feature of this invention, the vertically upstanding weight plates are arranged side-by-side in spaced parallel alignment with one another in a horizontally extending plurality of weight plates. A total of seven weight plates are shown in  FIG. 7 , but the particular number of weight plates to be lifted by carriage  3  during any exercise routine is a matter of choice. The first two weight plates  100  and  101  from the horizontal plurality have an identical length (e.g., ten inches). The first weight plate  100  has an ideal weight of 5 pounds, and the second weight plate  101  has an ideal weight of 10 pounds. The remaining five weight plates  102 ,  103 ,  104 ,  105  and  106  from the horizontal plurality have an identical but longer length (e.g., twenty two inches) relative to weight plates  100  and  101 . Each of the weight plates  102 - 106  has an identical weight of preferably 20 pounds. 
       FIGS. 9-11  of the drawings illustrate the first two (i.e., the lightest) weight plate  100  and  101  from the horizontally extending plurality thereof being detachably connected to the weight plate carriage  3  that is located at one side of the exercise machine  1 . As was explained when referring to  FIG. 3 , a weight plate lifting block  64  is affixed to the carriage alignment column  50  which runs along one side of the weight plate carriage  3 . As was also explained, the hook-shaped weight plate clasp  66  is pivotally connected to the weight plate lifting block  64  at the top of the weight plate carriage  3  by means of a bolt  67 , and a pair of engagement pin receiving holes  68  and  69  are formed though lifting block  64  adjacent the bolt  67 . 
     Each of the first two weight plates  100  and  101  has a respective lifting cavity  112  and  114  extending downwardly from the top thereof and a removable locking cartridge  116  and  118  mounted at one side thereof by a pair of screws  120 . The lifting cavities  112  and  114  of weight plates  100  and  101  are sized to receive therewithin the weight plate lifting block  64 . 
     Each of the locking cartridges  116  and  118  that is mounted at one side of respective weight plates  100  and  101  is identical to one another tend similar to that described in my U.S. Pat. No. 8,047,970 issued Nov. 1, 2011, the teachings of which are incorporated herein by reference. Therefore, only a brief description of one of the identical locking cartridges (e.g.,  116 ) will be described with respect to the weight plate  100  when referring particularly to  FIGS. 10 and 11 . 
     The locking cartridge  116  includes a lock body  122 . A longitudinal engagement pin channel  124  (best shown in  FIG. 11 ) extends through the lock body  122  towards the lifting cavity  112  that is formed in weight plate  100 . An engagement pin  126  is slidable reciprocally through the engagement pin channel  124  in the lock body  122  between a retracted position shown in  FIG. 10  at which the weight plate  100  is detached from the weight plate lifting block  64  received within the lifting cavity  112  and an axially extended position shown in  FIG. 11  at which the weight plate  100  is detachably connected to the weight plate lifting block  64 . 
     A user actuated control knob (i.e., switch)  128  communicates with one end of the engagement pin  126  by way of a pair of rotatable engagement pin positioning arms  130  and  132 . First ends of the positioning arms  130  and  132  are pivotally coupled to one another at a pivot pin  134  located inside the lock body  122  of locking cartridge  116 . The opposite end of one engagement pin positioning arm  130  is connected to the control knob  128 . The opposite end of the other engagement pin positioning arm  132  is coupled to the engagement pin  126  at a cavity thrilled therein. The engagement pin positioning arm  132  communicates with a torsion (e.g., coil) spring  136  within the lock body  122  of locking cartridge  116  to urge the positioning arm  132  to rotate in a clockwise direction around the pivot pin  134  and thereby cause the engagement pin  126  to be normally biased to the aforementioned retracted position of  FIG. 10  so as to be withdrawn within the longitudinal engagement pin channel  124 . 
     The control knob  128  is adapted to slide back and forth between locked and unlocked positions along a guide slot  138  (best shown in  FIG. 9 ) through the lock body  122  of the locking cartridge  116 . Depending upon whether the weight plate  100  and the particular weight (5 pounds) thereof is to be connected to the weight plate lifting block  64  and lifted by the weight plate carriage  3 , the engagement pin  126  is moved axially through the engagement pin channel  124  formed in the lock body  122  towards one of its retracted or extended positions in response to a pushing or pulling force applied by the user to the control knob  128 . The weight plate  100  is connected to the lifting block  64  when the control knob  128  is pushed through guide slot  138  to its locked position and the engagement pin  126  is correspondingly moved to its extended position (of  FIG. 11 ) for receipt within a locking channel  125  which runs through weight plate  100  and the engagement pin receiving hole  68  that is formed in lifting block  64  and axially aligned with locking channel  125 . 
     The same technique as just described for weight plate  100  is used if the second weight plate  101  shown in  FIG. 9  and the particular weight (10 pounds) thereof were to be detachably connected to the lifting block  64  to be lifted by the weight plate carriage  3 . In this case, with the lifting block  64  located within the lifting cavity  114  of weight plate  101 , the control knob  128  of the locking cartridge  118  can be pushed through guide slot  136  to its locked position so that the engagement pin from locking cartridge  118  will be moved to its extended position for receipt by the engagement pin receiving hole  69  that is formed in the lifting block  64  adjacent the pin receiving hole  68 . 
     Turning now to  FIGS. 12-16  of the drawings, details are provided by which any one or more of the remaining identical 20 pound weight plates  102 - 106  from the horizontally extending plurality thereof shown in  FIG. 8  are detachably connected to the weight plate carriage  3  of the exercise machine  1 . Each of the remaining weight plates (e.g.,  102 ) includes an identical removable locking cartridge  142  that is mounted within a cartridge cavity  143  located at one side of the weight plate and held in place by a pair of screws  144 . The locking cartridge  142  shown in  FIGS. 12-16  is identical to the locking cartridge designated  116  in  FIGS. 10 and 11 . Therefore, identical reference numerals will be used for both locking cartridges  116  and  142 , so that the details and operation of locking cartridge  142  will not be explained once again. 
     A hook retaining cavity  146  extends downwardly from the top of the weight plate  102 . Located within the cavity  146  is a hook-shaped weight plate clasp  148  which is identical to the hook-shaped clasp  66  that is shown in  FIG. 3  and connected to the weight plate lifting block  64  affixed to the weight plate carriage  3 . As is best shown in  FIG. 12 , a hole  150  formed through the top of the weight plate clasp  148  is axially aligned with a torsion (e.g., coil) spring  152  at one side of clasp  148  and a ring-shaped washer  154  at the opposite side for receipt therethrough of a threaded shoulder bolt  156 . The shoulder bolt  156  is received through a bolt hole  158  formed in the top of the weight plate  102  so as to run through the weight plate clasp  148  and laterally across the top of the hook retaining cavity  146 . Thus, and as is best shown in  FIGS. 13-16 , the shoulder bolt  156  connects the weight plate clasp  148  to the weight plate  102  within the cavity  146  thereof and establishes a pivot axis around which the weight plate clasp  148  can rotate. The torsion spring  152  is located within the hook retaining cavity  146  of weight plate  102  at which to engage and rotate the clasp  148  around shoulder bolt  156  and outwardly from cavity  146  (best shown in  FIG. 14 ). 
     Seated on the top of the weight plate  102  so as to lie over and cover the hook retaining cavity  146  thereof is a curved hook-deflecting strike plate  160 , the advantage of which will soon be described. A pair of engagement pin channels  161  and  162  are axially aligned with one another through the weight plate  102  at the opposite sides of the hook retaining cavity  146  (best shown in  FIG. 12 ). When the locking cartridge  142  is secured to the weight plate  102  within the cartridge cavity  143  at one side thereof, the engagement pin  126  is slidable between retracted and extended positions depending upon whether a pushing or a pulling force is applied to the control knob  128  of cartridge  142 . 
     When the weight plate  102  for any of the other weight plates  103 - 106  from the horizontal plurality of  FIG. 8 ) and the particular weight (20 pounds) thereof is to be lifted by the weight plate carriage  3 , the control knob  128  of the locking cartridge  142  is pushed along the guide slot  138  to its locked position. Pushing the control knob  128  correspondingly causes the engagement pin  126  to move outwardly from cartridge  142  to its extended position at which to be received through the axially aligned engagement pin channels  161  and  162  and thereby capture the hook-shaped weight plate clasp  148  within the hook retaining cavity  146 . When it is desirable to disconnect the weight plate  102  from the weight plate carriage  3 , the control knob  128  of the locking cartridge  142  is pulled through the guide slot  138  to its unlocked position. Pulling the control knob  128  in an opposite direction correspondingly causes the engagement pin  128  to move inwardly of cartridge  142  to its retracted position at which to be separated from and release the weight plate clasp  148 . 
     A roll pin  164  (best shown in  FIG. 12 ) extends outwardly from the locking cartridge  142  through a pair of roll pin channels  165  and  166  that are axially aligned with one another through the weight plate  102  at opposite sides of the hook retaining cavity  446 . The roll pin  164  is positioned within the hook retaining cavity  146  of weight plate  102  at which to engage the weight plate clasp  148  and thereby limit the rotation of the clasp through the cavity  146 . 
     The manner by which any one or more of the weight plates  100 - 106  from the horizontally extending plurality of weight plates shown in  FIG. 8  are selectively coupled to and lifted by one of the pair of weight plate carriages  3  of the exercise machine  1  is now described when referring to  FIGS. 17-19  of the drawings. As was previously explained, the first weight plate  100  from the horizontally extending plurality has a weight of 5 pounds, the second weight plate  101  has a weight of 10 pounds, and each of the third-seventh weight plates  102 - 106  has an identical weight of 20 pounds. Therefore, depending upon the number of weight plates that are selectively coupled to and lifted by the weight plate carriages  3  at opposite sides of the weight plate retention housing  4  of the exercise machine  1  shown in  FIGS. 1 and 2 , the user can lift between 5 to 115 pounds in 5 pounds increments with each arm as he applies successive pulling forces to the handles  28  of the machine  1  during his exercise routine. 
       FIG. 17  shows, for example, the weight plates  100 ,  102 ,  103  and  104  from the horizontally extending plurality of weight plates being selectively coupled to one weight plate carriage  3  located at one side of the weight plate retention housing  4  of the exercise machine  1  so that a total of 65 pounds will be lifted by one arm of the user when he applies a pulling force to one handle  28  of the machine. In this example, the other weight plates  101 ,  105  and  106  are not coupled to or lifted by the weight plate carriage  3 . 
     Referring to  FIGS. 9-11 and 17  of the drawings, the weight plate  100  is shown coupled to the weight plate carriage  3  when the control knob  128  of the locking cartridge  116  is pushed through the guide slot  138  from its unlocked position shown in  FIG. 10  to its locked position shown in  FIG. 11 . Pushing the control knob  128  of the locking cartridge  116  to the locked position causes the engagement pin  126  to correspondingly move through the engagement pin channel  124  formed in the lock body  122  of locking cartridge  116  and the axially aligned locking channel  125  formed in the weight plate  100  for receipt by the engagement pin receiving hole  68  formed in the weight plate lifting block  64 , whereby the weight plate  100  is detachably connected to the lifting block  64  and to the top of the weight plate carriage  3  to which the lifting block  64  is affixed. 
     With respect to the weight plate  101 , the control knob  128  of the locking cartridge  118  of  FIG. 9  is left in place in its unlocked position. In this case, the engagement pin  126  remains retracted within the engagement pin channel  124  formed in the lock body  122  of cartridge  118 , whereby the engagement pin  126  lies outside the engagement pin receiving hole  69  formed in the weight plate lifting block  64 , such that the weight plate  101  is disconnected from the weight plate carriage  3 . 
     Referring to  FIGS. 12-17  of the drawings, in addition to the weight plate  100 , each of the weight plates  102 ,  103  and  104  is also shown selectively coupled to the weight plate carriage  3  when the respective control knobs ( 128  in  FIG. 8 ) of the locking cartridges ( 142  in  FIG. 8 ) that are associated with weight plates  102 - 104  are pushed through guide slots  138  from their unlocked position (as shown) to their locked position. As an important feature of this invention for enabling the user to selectively couple some or all of the weight plates  100 - 106  to the weight plate carriage  3 , and as is best shown in  FIG. 17 , each of the hook-shaped weight plate clasps (e.g.,  148 ) that are pivotally connected to weight plates  102 - 104  is biased (i.e., pushed) by its torsion spring  152  (of  FIGS. 13-16 ) so as to rotated into the hook retaining cavity  146  that is formed in the succeeding weight plate lying immediately in front thereof. 
     It may be observed from  FIG. 17  that neither the first nor the last weight plates  100  and  106  has a weight plate clasp (i.e., book) connected thereto. Moreover, the clasp  66  that is pivotally connected to the weight plate lifting block  64  of the weight plate carriage  3  is rotated by a torsion (e.g., coil) spring  65  (of  FIG. 9 ) forwardly of weight plate  101  and into the hook retaining cavity  146  (of  FIG. 14 ) of weight plate  102  to be captured by the engager eat pin  126  of locking cartridge  142  (of  FIG. 12 ) of weight plate  102 . What is more, and as may also be observed from  FIG. 17 , the rotatable clasp  148  pivotally connected to weight plate  102  is pushed by its torsion spring  152  (of  FIG. 12 ) so as to rotate forwardly and into the hook retaining cavity of weight plate  103 , the rotatable clasp  148 - 1  pivotally connected to weight plate  103  is rotated into the hook retaining cavity of the weight plate  104 , the rotatable clasp  148 - 2  pivotally connected to weight plate  104  is rotated into the hook retaining cavity of weight plate  105 , and the rotatable clasp  148 - 3  pivotally connected to weight plate  105  is rotated into the hook retaining cavity of weight plate  106 . 
     With the weight plate carriage  3  at-rest as shown in  FIGS. 4 and 17 , no pulling force is applied to the weight plate carriage lifting cable  44  such that none of the weight plates  100 - 106  is being lifted by the weight plate carriage  3 . When the control knobs  128  of each of the locking cartridges  142  of the weight plates  102 - 104  (of  FIG. 8 ) are pushed to their locked position, the engagement pins  126 ,  126 - 1  and  126 - 2  from respective ones of the locking cartridges  142  of weight plates  102 - 104  are correspondingly pushed through their axially aligned engagement pin channels  161  and  162  (of  FIG. 12 ). The engagement pins  126 ,  126 - 1  and  126 - 2  thusly capture the hook-shaped weight plate clasps  66 ,  148  and  148 - 1  that are located within the hook retaining cavities  146  of those weight plates  102 ,  103  and  104  that are selected by the user to be lifted by the weight plate carriage  3 . 
       FIGS. 5, 6 and 18  show the weight plate carriage  3  being lifted in the vertical direction through the weight plate retention housing  4  of  FIGS. 1 and 2  relative to the carriage stabilizer posts  76  and  78  when an upward pulling force is applied to the weight plate lifting cable  44  in response to the user applying a pulling force to one of the handles  28  of the exercise machine  1  as shown in  FIG. 1 . As previously explained, when the carriage  3  is pulled upwardly, the pairs of upper and lower rollers  56 ,  57  and  58 ,  59  thereof roll along the carriage stabilizer posts  76  and  78 . Because they are coupled to the weight plate carriage  3  by way of the weight plate lifting block  64  and the weight plate clasps  66 ,  148  and  148 - 1 , the weight plates  100 ,  102 ,  103  and  104  will all be simultaneously lifted. Because they are not coupled to the weight plate carriage  3  at the weight plate lifting block  64  thereof, the remaining weight plates  101 ,  105  and  106  will not be lifted and will remain stationary during the exercise routine. 
     Of course, and without having to leave his seat ( 22  of  FIG. 2 ), the user can selectively change the number of weight plates  100 - 106  that are coupled to and lifted by the weight plate carriage  3  to increase or decrease the weight to be tilled during his exercise routine. The foregoing is accomplished by simply pushing or pulling different ones of the control knobs  128  of the locking cartridges  116 ,  118  and  142  (of  FIG. 8 ) to their locked or unlocked positions. 
       FIG. 19  of the drawings shows the weight plate carriage  3  being lowered by gravity relative to the carriage stabilizer posts  76  and  78  when the user terminates the pulling force applied to the handle  28  which in turn terminates the upward pulling three being applied to the weight lifting cable  44 . Because the weight plate  105  was not lifted, the hook-shaped weight plate clasp  148 - 2  that is pivotally connected to and rotated outwardly from the preceding weight plate  104  is not captured by the engagement pin from the locking cartridge  142  (of  FIG. 8 ) carried by the succeeding weight plate  105 . Thus, the hook end of the weight plate clasp  148 - 2  remains free in front of the weight plate  104 . 
     As the weight plate carriage  3  is lowered towards its at-rest position of  FIG. 17 , the outwardly rotated weight plate clasp  148 - 2  moves into contact with the curved hook-deflecting strike plate (designated  160  in  FIG. 16 ) at the top of weight plate  105 . The curved strike plate  160  urges the clasp  148 - 2  to momentarily rotate rearwardly against the normal bias of the torsion spring  152  (of  FIG. 16 ) towards the preceding weight plate  104  by which to enable all of the uplifted weight plates  100 ,  102 ,  103  and  104  to move downwardly towards those weight plates  101 ,  105  and  106  which were not lifted. Once the weight plate carriage  3  is lowered to its at-rest position of  FIG. 17 , the torsion spring  152  (of  FIG. 16 ) will automatically expand and push the weight plate clasp  148 - 2  forwardly towards and into the hook retaining cavity  146  of the adjacent weight plate  105  as shown in  FIG. 17 .