Dumbbell and exercise system having dumbbell

1. A dumbbell, comprising:

a hand-hold assembly, having a first channel and two opposite ends;

two weight adjusting assemblies, connected with the two opposite ends of the hand-hold assembly respectively and rotated relative to the hand-hold assembly about a rotation axis;

a plurality of weights, supported by the weight adjusting assembly; wherein,

each weight adjusting assembly comprises a first cover rotatably connected with one of the two opposite ends of the hand-hold assembly, a supporting base fixed to the first cover and having an upper sub-base and a lower sub-base spaced apart from the upper sub-base for forming a receiving space, and an engaging tube extending from the first channel into the receiving space and moved toward or away from the hand-hold assembly so that the engaging tube locks the weights or unlocks the weights, the hand-hold assembly comprises a hand-hold tube and a pair of connection members connected respectively with the ends of the hand-hold assembly; the first cover has a center hole; each of the two opposite ends of the hand-hold assembly passes through the respective center hole, the hand-hold assembly further comprises a pair of first elastic plungers, the first elastic plungers are respectively mounted on the two opposite ends of the hand-hold assembly and extend into the corresponding first channel.

2. The dumbbell according to claim 1 , wherein, the engaging tube has an inner wall and an outer wall opposite to the inner wall, a second channel formed in the inner wall, and a spiral groove is formed on the outer wall; each of the pair of first elastic plungers is inserted into the respective spiral groove.

3. The dumbbell according to claim 2 , wherein, each of the weight adjusting assemblies further comprises a second cover and a strength block received in the second cover; one end of the supporting base is fixed to the first cover and the other end of the supporting base is fixed to the strength block.

4. The dumbbell according to claim 3 , wherein, each of the weight adjusting assemblies further comprises a third cover connecting the first cover to the second cover.

5. The dumbbell according to claim 4 further comprising a connecting rod passing through the first channel and the second channel with both ends thereof fixed to the strength blocks.

6. The dumbbell according to claim 1 , wherein, each of the pair of connection members comprises a carrying disk and an engaging ring protruded from the carrying disk in g rotation axis direction toward the first cover; the first cover assembled with the carrying disk and abuts against the carrying disk.

7. The dumbbell according to claim 6 , wherein, the weight adjusting assembly further comprises an elastic locking assembly mounted on the first cover, the elastic locking assembly comprises a pressing block, an elastic member with one end connected with the pressing block and the other end abuts against the first cover;

the engaging ring comprises a plurality of interval space;

the pressing block is pushed into the interval space so that the first cover stops rotating; or,

the pressing block is not pushed into the interval space so that the first cover rotates about the rotation axis.

8. The dumbbell according to claim 7 , wherein, the weight adjusting assembly further comprises a second elastic plunger mounted on the first cover; the engaging ring further comprises a receiving hole for receiving the second elastic plunger while the first cover rotates to a right position where the second elastic plunger is axially aligned with the receiving hole.

9. The dumbbell according to claim 1 , wherein, each of the upper sub-base and the lower sub-base has a guiding slot, the guiding slots are formed on a side of the upper sub-base and a side of the lower sub-base close to the receiving space; the engaging tube has two protruding parts located at an end thereof, the protruding parts are inserted into the guiding slots respectively.

10. An exercising system, comprising:

a dumbbell comprising: a hand-hold assembly, having a first channel and two opposite ends;

two weight adjusting assemblies, rotatably connected with the two opposite ends of the hand-hold assembly respectively and rotated relative to the hand-hold assembly about a rotation axis;

a plurality of weights, supported by the weight adjusting assembly; wherein,

each weight adjusting assembly comprises a first cover rotatably connected with one of the two opposite ends of the hand-hold assembly, a supporting base fixed to the first cover and having an upper sub-base and a lower sub-base spaced apart from the upper sub-base for forming a receiving space, and an engaging tube extending from the first channel into the receiving space and moved toward or away from the hand-hold assembly so that the engaging tube locks the weights or unlocks the weights, the hand-hold assembly comprises a hand-hold tube and a pair of connection members connected respectively with the ends of the hand-hold assembly; the first cover has a center hole; each of the two opposite ends of the hand-hold assembly passes through the respective center hole, the hand-hold assembly further comprises a pair of first elastic plungers, the first elastic plungers are respectively mounted on the two opposite ends of the hand-hold assembly and extend into the corresponding first channel;

a dumbbell seat, configured for carrying the dumbbell.

11. The exercising system according to claim 10 , wherein, the dumbbell seat comprises a pair of weight carrying parts and a middle part located between the weight carrying parts; the weight carrying parts is configured for carrying the weights and the weight adjusting assemblies.

12. The exercising system according to claim 11 , wherein, the middle part is formed as a groove.