Dumbbell

Abstract

The present invention relates to a dumbbell and especially relates to an improvement on an assembly mode of a grip rod and flanges at both ends thereof in the dumbbell. The present invention axially positions the grip rod and the flange by the assembly of the first assembly groove in an L shape on the grip rod and the positioning block on the flange, then circumferentially positions the grip rod and the flange by plugging a positioning pin in the first assembly groove of the grip rod and the second assembly groove of the flange simultaneously, in cooperation with the shaft-hole fitting of the grip rod and the flange themselves, thereby implementing screw-free installation of the grip rod and the flange, simple manufacturing, a low cost and a high installation efficiency.

What is claimed is: 
     
         1 . A dumbbell, comprising:
 a grip rod,   flanges assembled at both ends of the grip rod, and   a positioning pin, wherein:
 an end portion of the grip rod is provided with a first assembly groove, 
 the first assembly groove comprises a first vertical groove that is arranged in an axial direction of the grip rod from an end face of the grip rod and a first horizontal groove that is arranged in a circumferential direction of the grip rod, 
 the first vertical groove and the first horizontal groove are in communication and joined so that the first assembly groove is in an L shape, 
 each of the flanges has a center hole, 
 the center hole has a first hole end and a second hole end, 
 a diameter of the center hole matches an outer diameter of the end portion of the grip rod, 
 the end portion of the grip rod is inserted into the center hole from the first hole end, 
 an inner wall of the center hole is provided with a second assembly groove, 
 the second assembly groove comprises a second vertical groove that is arranged in an axial direction of the center hole from the second hole end, 
 the inner wall of the center hole is fixedly provided with a positioning block adjacent to the second vertical groove, 
 a shape of the positioning block matches the first assembly groove, 
 the positioning block is aligned and inserted into the first vertical groove and follows along the first vertical groove to abut a groove bottom of the first vertical groove, 
 the grip rod and each of the flanges are relatively rotatable to make the positioning block snap into the first horizontal groove, and 
 the positioning pin is inserted into the first vertical groove and the second vertical groove simultaneously to restrict relative rotation of the grip rod and each of the flanges, thereby implementing axial positioning and circumferential positioning of the grip rod and each of the flanges. 
   
     
     
         2 . The dumbbell of  claim 1 , wherein:
 groove widths of the first vertical groove and the second vertical groove are equal, and   the positioning block and the second vertical groove are combined to form an L-shaped structure matching the first assembly groove so that when the positioning block is snapped into the first horizontal groove, the first vertical groove and the second vertical groove are configured to overlap.   
     
     
         3 . The dumbbell of  claim 1 , wherein:
 the second assembly groove further comprises a second horizontal groove that is arranged in the second hole end in a circumferential direction of the center hole,   the second horizontal groove is in communication with the second vertical groove so that the second assembly groove is in an inverted L shape, and   the positioning pin is in an inverted L shape and comprises an axial extension matching the first vertical groove and the second vertical groove and a circumferential extension matching the second horizontal groove.   
     
     
         4 . The dumbbell of  claim 1 , wherein:
 a groove wall of at least one side of the second vertical groove defines a concave U-shaped structure, and   a side edge corresponding to a groove wall of the positioning pin defines a convex U-shaped structure.   
     
     
         5 . The dumbbell of  claim 1 , wherein the second hole end is provided with a reduced diameter step for limiting the end portion of the grip rod. 
     
     
         6 . The dumbbell of  claim 1 , wherein an end portion of the positioning block facing away from the second hole end is flush with a groove bottom of the second vertical groove. 
     
     
         7 . The dumbbell of  claim 1 , wherein:
 there are two of the first assembly grooves that are 180° symmetrically disposed at each end portion of the grip rod, and   there are two of the second assembly grooves that are 180° symmetrically disposed corresponding to the first assembly grooves.   
     
     
         8 . The dumbbell of  claim 1 , wherein:
 the first assembly groove and the second assembly groove are rectangular grooves, and   the positioning block is rectangular.   
     
     
         9 . The dumbbell of  claim 1 , wherein:
 the grip rod is a tubular structure having an inner hole,   the tubular structure comprises an inner tube and an outer tube sleeved and fixed on an outer periphery of the inner tube,   both ends of the inner tube are exposed out of the outer tube,   the first assembly grooves are disposed at both ends of the inner tube,   both ends of the outer tube are provided with inserting portions convexly protruding along an axial direction of the outer tube,   each of the flanges has slots matching the inserting portions, and   the inserting portions are in an inserted-sleeved connection with the slots when the grip rod is inserted into the center hole.