Weight-adjustable dumbbell

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.

1 . A dumbbell comprising: 
 a dumbbell base having at least one locating hole;    a plurality of weights detachably mountable on said dumbbell base, said weights each having at least one through hole corresponding to the at least one locating hole of said dumbbell base; and    at least one lock pin insertable into the at least one locating hole of said dumbbell base and the at least one through hole of said weights to selectively secure said weights to said dumbbell base.    
   
   
       2 . The dumbbell as claimed in  claim 1 , wherein said weights each have a slot and a mounting flange adjacent to the slot, said mounting flange having two sidewalls and a top wall connected between said sidewalls, said sidewalls being provided with the at least one through hole of the respective weight, the mounting flange of one of said weights being overlapped on the mounting flange of another one of said weights to have each through hole of each weight in alignment with one locating hole of said dumbbell base when a number of said weights are attached to said dumbbell base.  
   
   
       3 . The dumbbell as claimed in  claim 2 , wherein said dumbbell base comprises at least one open chamber in communication with said locating holes for receiving the mounting flanges of said weights.  
   
   
       4 . The dumbbell as claimed in  claim 1 , wherein said weights each comprise a locating pin, said locating pin having a recess at one end thereof; wherein the locating pin of one of said weights is positioned in the recess of the locating pin of another one of said weights when a number of said weights are mounted on said dumbbell base.  
   
   
       5 . The dumbbell as claimed in  claim 1 , wherein said dumbbell base comprises a bar and two holder portions respectively provided at two distal ends of said bar; the at least one locating hole of said dumbbell is respectively defined in said holder portions.  
   
   
       6 . The dumbbell as claimed in  claim 1 , further comprising a connecting rod fixedly connected between two of said weights for supporting the others of said weights in said dumbbell base; said dumbbell base comprises at least one groove for accommodating said connecting rod.  
   
   
       7 . The dumbbell as claimed in  claim 1 , wherein said at least one lock pin each comprises a shank, and a retaining device provided at one end of said shank for securing the respective lock pin to said dumbbell base.  
   
   
       8 . The dumbbell as claimed in  claim 7 , wherein said retaining device comprises at least one steel ball movably mounted in the shank of the respective lock pin and a spring member mounted in the shank of the respective lock pin to support said at least one steel ball and to force said at least one steel ball partially out of the periphery of the shank of the respective lock pin.