Abstract:
A weight-adjustable dumbbell includes a dumbbell base, which has a plurality of locating holes, a plurality of weights, which are detachably mountable on the dumbbell base, each having a plurality of through holes corresponding to the locating holes of the dumbbell bases, and a plurality of lock pins insertable into the locating holes of the dumbbell base and the through holes of the weights to selectively secure the weights to the dumbbell base.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to a dumbbell and more particularly, to a weight-adjustable dumbbell.  
         [0003]     2. Description of the Related Art  
         [0004]     When making a body building exercise, a dumbbell is commonly used to train the muscles. There are dumbbells that allow the user to adjust the total weight. A weight-adjustable dumbbell generally comprises a bar, a plurality of weights selectively detachably mounted on the ends of the bar, and two screw caps respectively threaded onto the ends of the bar to lock the loaded weights. When adjusting the total weight of the dumbbell, the user must detach the screw caps from the bar, and then remove some of the weights from the bar or attach new weights to the bar, and then fasten the screw caps to the bar again after loading of the selected weights. This adjusting procedure is complicated. Further, if the end caps are not fastened tight or the weights are not evenly arranged on the two ends of the bar, the user may be unable to keep the dumbbell in balance when lifting the dumbbell, thereby causing an accident.  
       SUMMARY OF THE INVENTION  
       [0005]     The present invention has been accomplished under the circumstances in view. It is one object of the present invention to provide a dumbbell, which allows the user to adjust the total weight of the dumbbell conveniently.  
         [0006]     To achieve the above-mentioned object, the weight-adjustable dumbbell provided by the present invention comprises a dumbbell base having at least one locating hole; a plurality of weights detachably mountable on the dumbbell base, the weights each having at least one through hole corresponding to the at least one locating hole of the dumbbell base; and at least one lock pin insertable into the at least one locating hole of the dumbbell base and insertable into the at least one through hole of the weights to selectively secure the weights to the dumbbell base. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]      FIG. 1  is a perspective view of a weight-adjustable weight according to the present invention.  
         [0008]      FIG. 2  is an exploded view of the weight-adjustable dumbbell according to the present invention.  
         [0009]      FIG. 3  is a front view of the weight-adjustable dumbbell according to the present invention.  
         [0010]      FIG. 4  is a side view of the weight-adjustable dumbbell according to the present invention.  
         [0011]      FIG. 5  is a top view of the weight-adjustable dumbbell according to the present invention.  
         [0012]      FIG. 6  is a sectional view taken along line  6 - 6  of  FIG. 4 .  
         [0013]      FIG. 7  is a sectional view taken along line  7 - 7  of  FIG. 3 .  
         [0014]      FIG. 8  is a sectional view taken along line  8 - 8  of  FIG. 3 .  
         [0015]      FIG. 9  is a schematic drawing of the present invention, showing a number of weights separated from the dumbbell base. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0016]     Referring to  FIG. 1 , a weight-adjustable dumbbell in accordance with the present invention is shown comprising a dumbbell base  11 , a plurality of weights  21 - 29 , and two lock pins  91 . The weights  21 - 29  are respectively arranged at two sides of the dumbbell base  11 . The two lock pins  91  are detachably fastened to the dumbbell base  11  at two sides.  
         [0017]     Referring to  FIGS. 2 through 5 , the dumbbell base  11  comprises a bar  12 , and a holder portion  13  at each of the two distal ends thereof. Each holder portion  13  has a recess  14  at each of the front and back sides, a groove  15  at the bottom side, a plurality of locating holes  16  symmetrically arranged at two sides at different elevations in a staggered manner between the two recesses  14 , numerical marks  19  marked in the front recess  14  corresponding to the locating holes  16  for indicating the total weight of the weight-adjustable dumbbell, a substantially inverted U-shaped stop plate  17  mounted in the back recess  14  around the corresponding locating holes  16 , and an open chamber  18  at an outer side in communication between the locating holes  16 . Further, the total weight of the dumbbell base  11  is about 5 lbs.  
         [0018]     The weights  21 - 29  are heavy plates each having a weight about 2.5 lbs. The weights  21 - 29  each have a slot  31 - 38 , and a substantially inverted U-shaped mounting flange  4148  adjacent to the slot  31 - 38 . The substantially inverted U-shaped mounting flange  4148  has two sidewalls  51 - 58  and a top wall  61 - 68  connected between the sidewalls  51 - 58 . The weights  21 - 29  have a different pitch between the sidewalls  51 - 58  and a different elevation among the top walls  61 - 68 . Further, a connecting rod  39  is connected between the two outer weights  29 .  
         [0019]     Referring to  FIGS. 4 and 5 , when the weights  21 - 29  are set in the dumbbell base  11  at two sides, the mounting flanges  41  of the weights  21  are respectively received in the open chambers  18  of the two holder portions  13  of the dumbbell base  11 ; the mounting flanges  42  of the weights  22  are respectively inserted through the slots  31  of the weights  21  into the space between the two sidewalls  51 ; the mounting flanges  43  of the weights  23  are respectively inserted through the slots  32  of the weights  22  into the space between the sidewalls  52 ; the mounting flanges  44 - 48  of each of the other weights  24 - 28  are respectively inserted through the slots  33 - 37  of each of the weights  23 - 27  in the space between the corresponding sidewalls  53 - 57 . When assembled, the mounting flanges  41 - 48  are attached to one another in proper order to keep the top walls  61 - 68  vertically spaced from one another at a predetermined distance, and the top side of the connecting rod  39  is spaced from the top wall  68  of the weight  28  at a distance.  
         [0020]     The top wall  61 - 68  of the mounting flange  41 - 48  has a downwardly extending pointed locating pin  81 . The locating pin  81  has a head  82  protruding over the top side of the top wall  61 - 68 . The head  82  has a top recess  83 . When the weights  21 - 29  are set in the dumbbell base  11  at two sides, the heads  82  of the locating pins  81  at the top walls  61  are respectively received in respective open chamber  18  in the holder portions  13 ; the bottom ends of the locating pins  81  at the top walls  61  are respectively received in the recesses  83  of the locating pins  81  at the top walls  62 ; the bottom ends of the locating pins  81  at the top walls  62  are respectively received in the recesses  83  of the locating pins  81  at the top walls  63 ; the bottom ends of the locating pins  81  at the top walls  63 - 67  are respectively received in the recesses  83  of the locating pins  81  at the top walls  64 - 68 ; the; the bottom ends of the locating pins  81  at the top walls  68  are respectively received in respective holes  84  at the connecting rod  39 . Therefore, the weights  21 - 29  are secured together by means of the locating pins  81 .  
         [0021]     As shown in  FIGS. 2 and 6 , the sidewalls  51 - 58  of the mounting flanges  4148  each have at least one through hole  71 - 78  corresponding to each other, and the connecting rod  39  between the two weights  29  has two through holes  79 . When the weights  21 - 29  are set in the dumbbell base  11  at two sides, the through holes  71 - 78  of the mounting flanges  4148  and the through holes  79  of the connecting rod  39  are in communication with the respective locating holes  16  at the dumbbell base  11 , and the topmost through holes  71 - 78  of the mounting flanges  41 - 48  are respectively communicated with one of the locating holes  16  at the holder portion  13 .  
         [0022]     As shown in  FIGS. 5-8 , each lock pin  91  has a round shank  93 , a head  94  at one end of the round shank  93 , and a retaining device  95  at the other end of the round shank  93 . The retaining device  95  is comprised of two steel balls  96  and a spring member  97 . The steel balls  96  are movably mounted in the round shank  93  and partially forced out of the periphery of the round shank  93  by the spring member  97 .  
         [0023]     The round shank  93  of each of the lock pins  91  can be respectively inserted through the locating holes  16  of the dumbbell base  11  and the through holes  71 - 79  of the weights  21 - 29 , keeping the head  94  of each of the lock pins  91  respectively received in the recess  14  at the front side of the holder portion  13  at each of the two distal ends of the dumbbell base  11  and the retaining device  95  of each of the lock pins  91  respectively suspending in the recess  14  at the back side of the holder portion  13  at each of the two distal ends of the dumbbell base  11 . Therefore, the steel balls  96  of each lock pin  91  are forced outwards by the respective spring member  97  into engagement with the inside wall of the respective recess  14  to lock the weights  21 - 29  to the dumbbell base  11 .  
         [0024]     Referring to  FIGS. 3-8  again, if the locating pins  91  are set in the locating holes  16  corresponding to “50” of the numerical marks  19 , the round shanks  93  of the locating pins  91  are respectively inserted through the through holes  71 - 79  corresponding to the corresponding locating holes  16  and positioned in the respective holder portions  13 , joining the weights  21 - 29  to the dumbbell base  11 . When the user holds the bar  12  of the dumbbell base  11  to lift the weight-adjustable dumbbell, the weights  21 - 29  are carried by the dumbbell base  11  by means of the lock pins  91  and the locating pins  81 , therefore the user can proceed with an about 50 lbs weight training.  
         [0025]     Referring to  FIG. 9 , if the user wishes to proceed with an about 30 lbs weight training, the user must insert the lock pins  91  in the through holes  16  corresponding “30” of the numerical marks  19 . At this time, the round shanks  93  of the lock pins  91  are respectively inserted through the through holes  71 - 75  to secure the weights  21 - 25  to the dumbbell base  11 . When the user lifts the dumbbell base  11 , the weights  21 - 25  are moved with the dumbbell base  1 , making a 30 lbs weight training. Because the weights  26 - 28  are supported on the connecting rod  39  between the weights  29  and attached to one another, the weights  26 - 29  are prohibited from biasing, and the user can conveniently load and unload the weights  21 - 29 . Further, when the lock pins  91  are mounted in the through holes  16  corresponding to “5” of the numerical marks  19 , the lock pins  91  are positioned in the holder portions  13  of the dumbbell base  11 , and the user can use the weight of 5 lbs of the dumbbell base  11  itself to make a weight training.  
         [0026]     Although a particular embodiment of the invention has been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims.