Adjustable dumbbell

Abstract

The present invention relates to an adjustable dumbbell, which includes a rotatably disposed grip rod and a locking element, wherein a locking portion is disposed at both ends of the grip rod, the locking element includes a base, a movable pin and a compression spring, the movable pin is slidably disposed in the base, the base is provided with a first spring sleeve column, the movable pin is provided with a second spring sleeve column, and both ends of the compression spring are respectively sleeved and positioned on the first spring sleeve column and the second spring sleeve column. In the present invention, the base and the movable pin are both provided with the spring sleeve column, which is not only convenient to mount and position the compression spring during assembly, but also can prevent the compression spring from falling out due to the shaking of dumbbells in use.

What is claimed is: 
     
         1 . An adjustable dumbbell, comprising:
 a dumbbell piece adjustment system, and   a locking element, wherein:
 the dumbbell piece adjustment system is used to adjust a number of dumbbell pieces attached to the adjustable dumbbell, 
 the dumbbell piece adjustment system has a locking portion, 
 the locking element comprises a base, a movable pin, and a compression spring, 
 the movable pin is slidably disposed in the base, 
 the base is provided with a first spring sleeve column, 
 the movable pin is provided with a second spring sleeve column, 
 both ends of the compression spring are respectively sleeved and positioned on the first spring sleeve column and the second spring sleeve column and respectively abut the base and the movable pin, and 
 the movable pin is tensioned to an outside of the base by an elastic restoring force of the compression spring and clamped into the locking portion, thereby locking the dumbbell piece adjustment system. 
   
     
     
         2 . The adjustable dumbbell according to  claim 1 , wherein the compression spring, the first spring sleeve column, and the second spring sleeve column are provided with two sets side-by-side. 
     
     
         3 . The adjustable dumbbell according to  claim 1 , wherein:
 the base is provided with a U-shaped convex slideway,   the movable pin has a sliding groove having a shape that matches the U-shaped convex slideway, and   the sliding groove and the U-shaped convex slideway are slidingly fitted.   
     
     
         4 . The adjustable dumbbell according to  claim 3 , wherein:
 a main body of the movable pin is rectangular in shape and has a first side edge and a second side edge on an opposite side of the main body relative to the first side edge,   the first side edge and the second side edge are respectively provided with two sliding grooves side-by-side,   the base has a rectangular inner groove adapted to the movable pin, and   two opposite groove walls of the rectangular inner groove are respectively provided with the two sliding grooves side-by-side.   
     
     
         5 . The adjustable dumbbell according to  claim 1 , wherein:
 the dumbbell piece adjustment system comprises a grip rod, flange driving members, a planetary gear system, and a telescopic rod,   the flange driving members are fixedly assembled at both ends of the grip rod,   the planetary gear system comprises an outer casing and a planetary gear mechanism disposed in the outer casing,   the telescopic rod is helically driven by the planetary gear mechanism so that when the grip rod is rotated, the flange driving members drive the planetary gear mechanism to rotate and make the telescopic rod extend and retract, thereby adjusting the number of dumbbell pieces attached to the adjustable dumbbell,   the locking element is fixedly mounted on the outer casing,   the flange driving members extend into the outer casing,   one end of each of the flange driving members toward the outer casing is provided with a locking ring with an annular structure, and   the locking portion is a notch disposed on the locking ring and matching a shape of the movable pin.   
     
     
         6 . The adjustable dumbbell according to  claim 5 , wherein:
 the planetary gear mechanism comprises a ring gear, a planetary wheel, a planetary carrier, and a sun wheel,   the planetary carrier is fixed on the outer casing,   the ring gear is in linkage connection with each of the flange driving members,   the sun wheel is a gear shaft with a shaft hole, and   the telescopic rod is connected in the shaft hole of the gear shaft through a screw pair.