referring to the drawings , there is shown in fig1 through 3 a weight lifting exercise machine according to one form of the invention , indicated generally at 10 . machine 10 has an overall frame 11 with a first upright member comprised as a support and guide rail 12 ; and a second upright front support member 14 . an overhead beam 15 connects the upper ends of the support members 12 , 14 and overhangs the front support member 14 . a frame stand includes a horizontal lateral leg 16 connected to a longitudinal horizontal leg 18 in a “ t ” shape . the lower ends of the support members 12 , 14 are connected to the longitudinal leg 18 . a foot brace 25 is assembled to the end of the leg 18 opposite its connection to the lateral leg 16 . an exercise station includes an horizontal bench support beam 20 pivotally connected to and extending forward from the lower portion of the second upright structural member 14 . the outer end of the support beam 20 is connected to a vertical leg 21 attached to a horizontal leg 29 . a weight bench includes a seat 22 attached to the support beam 20 , and a backrest 23 . backrest 23 is positioned adjacent to seat 22 and is connected at one end to a hinge structure 24 so that it can be pivoted up and down , or from the upright position shown in fig1 through 3 , to a flat horizontal position . the back rest 23 is held upright by a u - shaped rod 26 that interconnects with notches in a positioning bracket 27 . a dumbbell carrier is assembled to the guide rail 12 for up and down sliding movement on the guide rail . as shown in fig1 through 3 , carrier 30 carries a dumbbell weight 31 . the structure of carrier 30 is more particularly shown in fig4 and 5 . the carrier 30 has dumbbell racks or receptacles comprised as a pair of brackets 33 , 34 positioned in back to back relationship and separated by a carriage structure . each bracket has a plurality of openings for receipt of the bar of a dumbbell . first bracket 33 has side plates 35 , 36 connected by a back plate 38 . a first side plate 35 has a series of vertically spaced , hook - shaped edge openings 39 a , 40 a , 42 a . second side plate 36 has a corresponding plurality of edge openings 39 b , 40 b , 42 b . each of the edge openings defines a pocket for receipt of a section of a dumbbell bar . the bar of the dumbbell is engageable in a pair of corresponding openings . a plurality of such bars can be accommodated by each bracket . the openings are upwardly open and hook - shaped to inhibit unintended disengagement of the bar from the bracket . the second bracket 34 similarly has side plates 43 , 44 and a back plate 46 . the second bracket 34 also has a plurality of hook - shaped edge openings arranged in corresponding pairs . the first and second carrier brackets 33 , 34 are connected to a carriage structure for movement up and down the guide rail 12 . this carriage structure includes the backplates 38 , 46 of the brackets 33 , 34 , and sidewall structures 47 , 48 . each of the sidewall structures 47 , 48 includes a channel shaped member connected to the backplates 38 , 46 of brackets 33 , 34 by nut and bolt assemblies 50 . the backplates and sidewall structures form a guide opening 54 that is slightly oversized with respect to the cross - sectional dimensions of the guide rail 12 . this permits up and down sliding movement of the dumbbell carrier 30 on the guide rail 12 . downward movement of the carrier 30 is stopped by stop members 57 . means can be provided , if necessary , to facilitate movement of the carrier 30 on guide rail 12 , such as rollers , grease , or the like . as shown , pads of low friction material are in place to facilitate movement of carrier 30 on rail 12 . referring to fig6 sidewall structure 48 has an end wall 49 and a short overlapping interior wall 51 . a slide pad 52 of teflon ® or similar low friction material is fastened to interior wall 51 in confronting relationship to rail 12 . in like fashion , slide pads 53 are fastened to the interior surfaces of the back plates 38 , 46 of brackets 33 , 34 . as shown in fig2 the standard dumbbell 31 has end weights 55 connected by a dumbbell bar 56 . the hook - shaped openings or pockets 39 , 40 , 42 are adapted to secure the dumbbell bar 56 in place . a number of dumbbells can be stacked in the bracket . as shown in fig4 the carrier can accommodate six dumbbells , three in each bracket . more or less could be provided . dumbbells of various weights can be loaded on to the carrier 30 according to the exercise prerogative of the user . for example , two forty - pound dumbbells can be loaded onto the carrier 30 , along with two ten - pound dumbbells and one five - pound dumbbell for a total loaded weight of 105 pounds plus the weight of the carrier 30 . weight increments can be added and subtracted according to the weights of the various dumbbells available . referring again to fig1 through 3 , a main weight handle 58 is connected to the carrier 30 so that movement of the weight handle 58 moves the carrier 30 against the influence of gravity . the connection between the weight handle and the carrier can be a system of levers , linkages , cables , belts , a combination thereof , or other such connecting means capable of transmitting a tension force . in the embodiment shown in fig1 through 3 , the weight handle is connected to the carrier 30 through a cable and pulley system . the cable can be wire , rope , chain , or the like or any combination thereof , capable of transmitting a tension force . the weight handle is readily detachable and interchangeable with other weight handles . for example , another weight handle can be shorter , or fashioned of rope . a weight handle could be fashioned as a head harness for neck exercise , or as a harness to fit other body parts according to the specialized exercise routine . a main cable 59 is fastened at one end to an eye clip 60 that is attached to the carrier 30 ( fig4 ). the other end of main cable 59 is fastened to another eye clip 62 that is centrally attached to the weight handle 58 . the intermediate segment of main cable 59 is trained over a pulley system which includes first , second and third pulleys , 63 , 64 and 65 , that are mounted in the overhead beam 15 . the overhead beam 15 can be a box beam with downwardly open slots so that pulley axles can be mounted between the sidewalls and carry pulleys as shown . the beam 15 extends forward from the front support member 14 . the weight handle 58 is positioned off of the forward tip of overhead beam 15 where it can be pulled away from overhead beam 15 in an action that lifts the carrier 30 along the guide rail 12 . return movement of the weight handle 58 is stopped by the overhead beam 15 . bench support beam 20 is removable from the overall frame 11 when not in use in order to provide clearance for the exercising person so approach the weight handle 58 standing . the inside end of beam 20 has a bracket 67 that engages a segment of the second support member 14 of frame 11 . a pin 68 passes through aligned holes in the bracket 67 and support member 14 to secure the beam in place . the support beam is removable simply by removal of the pin 68 and moving the beam 20 away from the frame . additionally , bench support beam can be pivoted upwardly about pin 68 as shown and described with respect to fig3 a . a secondary weight handle system lends versatility to the machine 10 . a secondary cable 71 is connected at a fixed end to frame 11 as at leg 18 of the frame stand . the opposite end of secondary cable 71 is connected to a second weight handle 72 . a pulley block 74 carries an upper pulley 75 and a lower pulley 76 . a segment 59 a of the main cable 59 is trained over upper pulley 75 . the segment 59 a is located between the first and second pulleys 63 , 64 of the pulley system of the first weight handle 58 . the secondary cable 71 is trained over the lower pulley 76 of pulley block 74 . a sixth pulley 78 is mounted at the lower end of the second support post 14 of frame 11 . a seventh pulley 79 is mounted in the vertical leg 21 that is attached to the support beam 20 . the secondary cable 71 extends from the lower pulley 76 to the sixth pulley 78 and then over the seventh pulley 79 to the connection at the second weight handle 72 . the second weight handle 72 shown in the configuration of fig1 through 3 is adapted for engagement by the ankles and lower legs of the exercising person . leg pads 81 , 82 are fastened to the ends of the second weight handle 72 . the second weight handle 72 is connected to the lower end of a pivot arm 83 . pivot arm 83 is pivotally connected to the upper end of a support member 85 . the lower end of support member 85 is fastened to the end of the horizontal support beam 20 . a padded support bar 86 is also connected to the support member 85 . the second weight handle 72 is engagable by the legs and ankles of the exercising person . the exercising person can be sitting on the seat 22 facing the support member 85 . the ankles engage the pads 81 , 82 on the second weight handle 72 in a lifting motion . this lifts the carrier 30 through the secondary cable 71 . alternatively , the exercising person can stand facing the machine and engage the back of the ankle on one of the pads 81 , 82 one leg at a time . from fig1 through 3 , it may easily been seen that the second weight handle 72 could be configured to be manually grasped by the exercising person and lifted to mimic lifting a barbell . fig3 a shows an embodiment of the invention of the form shown in fig1 through 3 wherein the bench support beam 20 is pivoted about the pin 68 to a position up against the second support member 14 and out of the way . a strap 73 or other suitable holding structure secures the bench support in the stored position . a secondary weight handle 72 a is available at the lower end of the second support member 14 . a foot brace 25 is assembled to the end of the leg 18 for use by a sitting exercising person . another form of the invention is shown in fig7 and indicated generally at 10 a . the machine 10 a is like the machine 10 shown in fig1 through 3 with the exception of a modified dumbbell carrier 30 a . the machine 10 a has a frame 11 including a first upright guide post and rail 12 , a second upright support member 14 , and an overhead horizontal beam 15 . frame 11 is supported on a stand which includes horizontal legs 16 , 18 . a support beam 20 carries a seat 22 with a back rest 23 . a weight handle 58 is connected through a cable 59 to the carrier 30 a . a second weight handle 72 is connected by a secondary cable 71 to the weight carrier 30 a for manipulation as described above . the carrier 30 a differs from the carrier 30 in that it only has a single receptacle bracket for engagement of dumbbells . the carrier 30 a has a bracket 88 with side plates 89 , 90 that have vertically spaced , hook - shaped edge openings arranged in pairs for receipt of dumbbell handles . the bracket 88 has a back plate 92 that together with sidewall structure 93 forms a carriage up and down movement on the guide rail 12 . dumbbells like the dumbbell 94 can be loaded on the carrier 88 according to the weight preference of the exercising person . [ 0038 ] fig4 a shows another weight carrier - guide rail configuration wherein two guide rails are provided . many existing weight machines currently employ a weight system using a pair of parallel guide rails , whereby the present invention can be retrofitted to such machines . the weight carrier is shown generally at 30 b and a pair of vertical guide rails are shown in phantom at 12 b and 12 c . the weight carrier 30 b has a top plate 37 fastened between the side walls 46 a , 47 a . top plate 37 has a pair of guide rail mounting openings 41 a , 41 b . the guide rails 12 b , 12 c are engaged in the openings 41 a , 41 b for up and down movement of the carrier on the guide rails . [ 0039 ] fig8 shows a yet further form of the invention indicated generally at 10 b . the form of the invention at 10 b differs from the earlier form of the invention indicated generally at 10 in fig1 through 3 in the structure of the dumbbell carrier and in the configuration of the exercise station . otherwise the machines are the same . machine 10 b has a frame 11 that includes a first support member or guide rail 12 and a second upright support member 14 connected by an overhead beam 15 . legs 16 and 18 stabilize the frame . a dumbbell carrier 30 b is connected to the main cable 59 that is trained over pulleys attached to the overhead beam 15 and then to the main weight handle 58 . the dumbbell carrier 30 b is adapted to carry hand weights or dumbbells having a box - like configuration , of the type sold under the trademark powerblock ®. the dumbbell carrier 30 b is more particularly shown in fig9 . the dumbbell carrier 30 b includes a carriage structure to straddle and ride along the guide rail 12 . the carriage structure includes lateral side wall structures 96 , 97 connected to back plates 98 , 99 by bolts 116 . a pair of receptacle baskets 101 , 102 are connected respectively to the back plates 98 , 99 . each basket 101 , 102 is adapted to carry one or more of the block style dumbbells 100 . for example , the basket 101 has a flat base or tray 104 connected to a back wall 103 which is in turn connected to a back plate 98 by bolts 108 . basket 101 has inclined side walls 105 , 106 and a front lip 107 for confining weights placed on the tray 104 of the basket 101 . an eye clip 110 is connected to the dumbbell carrier 30 b for connection to the main cable 59 of machine 10 b . referring back to fig8 the exercise station 112 includes a pair of horizontal , parallel tracks 113 , 114 and a seat assembly 115 mounted for sliding of movement on the tracks . seat assembly 115 faces frame 11 and is adapted to travel back and forth on the tracks relative to the frame . foot supports 117 , 118 are mounted at the inward ends of the tracks 113 , 114 . suitable connecting structure 119 releasably connects the tracks 113 , 114 and the foot supports to the frame 11 . a secondary weight handle 121 is connected to the free end of the secondary cable 71 where it is trained over the pulley 78 assembled in the second frame support member 14 . the inward limit of travel of the secondary weight handle 121 is the second support member 14 . pulling on the secondary weight handle 121 away from the frame 11 raises the weight carrier 30 b and any weights carried thereon through the secondary cable 71 trained over the pulley block assembly 74 . in use of the machine 10 b , the exercising person optionally engages either the main weight handle 58 or the secondary weight handle 121 . when engaging secondary weight handle 121 , the exercising person is seated on the seat assembly 15 with feet engaging the foot supports 117 , 118 . the exercising person engages the secondary weight handle 121 and pulls it away from the frame 11 , continuing the exercise routine by moving the secondary weight handle 121 away from and toward the frame 11 against the weight offered by the dumbbell carrier 30 b . a collection of one or more dumbbells is assembled on the trays of the baskets 101 , 102 . [ 0044 ] fig8 a shows a modification of the exercising machine of fig8 . the sliding seat assembly has been removed and a short seat assembly 109 has been installed . short seat assembly is assembled to the second support member 14 beneath the main weight bar 58 . hold down pads 111 are also assembled to the second support member 14 positioned for engagement by the thighs of the exercising person seated on short seat assembly 109 and pulling on weight handle 58 . a still further form of a weight lifting exercise machine according to the invention is shown in fig1 and indicated generally at 124 . the machine 124 includes an overall frame 125 that is relatively tall and open at the front . a stand for frame 125 includes front legs 126 , 127 and back legs 133 , 136 . each of the front legs 126 , 127 has a front foot 129 , 130 engaging the supporting surface , and a horizontal section 131 , 132 extending rearward from the foot . back legs 136 , 133 connect respectively at the base of each to the horizontal sections 131 , 132 of the front legs 129 , 130 . back legs 136 , 133 are connected brace 138 . each back leg 136 , 133 extends upwardly and is inclined forwardly , terminating in an upper horizontal section 134 , 135 . the ends of the upper sections 134 , 135 are connected by an overhead beam 137 . first and second generally vertical guide rails 141 , 143 carry first and second weight carriers 149 , 150 . weight carriers 149 , 150 ride up and down on the guide rails 141 , 143 . a weight handle 145 is connected at first and second ends respectively to the first and second carriers . the weight carriers can be loaded with dumbbells as the dumbbell 153 . the weight handle 153 is lifted against the weight resistance of the carriers and any weights carried by the carriers . a first vertical track member 139 is parallel to and spaced from the first guide rail 141 . a second such track member 142 is disposed in similar fashion to the second guide rail 143 . the guide rails and track members are connected to the horizontal leg sections 134 , 135 of the back legs , at their upper ends . the lower ends are connected to the horizontal sections 131 , 132 of the front legs . each of the track members has a vertical slot facing the corresponding guide rail . ends of the weight handle 145 have first and second guide members 146 , 147 , that have pegs or fingers 148 , 152 that ride in the slots of the track members for safety and stability when lifting and lowering the weight handle 145 . in use of the embodiment of the invention shown in fig1 , a plurality of dumbbells are loaded onto the weight carriers 149 , 150 to achieve a desired total weight . the exercising person stands in front of the frame 125 and grasps the weight handle 145 . frame 125 is relatively tall so as to permit the exercising person to stand under the overhead beam 137 . the exercising person lifts the weight handle 145 against the weight afforded by the dumbbells located on the weight carriers . the exercising person can engage in weight lifting exercises of the type normally accomplished with a barbell . the path of the weight handle is confined to up and down movement , a safety consideration .