Clamping device

A clamping device comprising:

• at least one elastic element comprising a first end and a second end;
• a first barrel attached to the first end of the at least one elastic element and comprising a bottom surface, a plurality of first clamping portions, a hole defined in the bottom surface, a plurality of first slots, and a first receiving space comprising the hole, the first clamping portions and the first slots being alternately arranged around the first receiving space;
• and
• a second barrel attached to the second end of the at least one elastic element and received in the first receiving space, the second barrel comprising a plurality of second clamping portions, a plurality of second slots, a second receiving space, and an engaging portion, the second clamping portions and the second slots being alternately arranged around the second receiving space;
• the hole of the first barrel configured for receiving the at least one elastic element and the engaging portion of the second barrel, and the second barrel being rotatable relative to the first barrel in the first receiving space between a first position where the at least one elastic element is in a relaxed state and the second clamping portions are close to the respective first clamping portions, and a second position where the second clamping portions are further from the corresponding first clamping portions and the at least one elastic element applies a torsional force on the first barrel and the second barrel to force the first clamping portions to move toward the corresponding second clamping portions.

A clamping device comprising:

• a first barrel comprising a plurality of spaced first clamping portions, the first clamping portions arranged along a first imaginary circle;
• a second barrel coaxially aligned with and received in the first barrel, the second barrel comprising a plurality of spaced second clamping portions arranged along a second imaginary circle, a diameter of the second imaginary circle being less than a diameter of the first imaginary circle;
• and
• a torsional spring member coupled between the first barrel and the second barrel, the second barrel being rotatable relative to the first barrel in the first receiving space between a first position where the torsional spring member is in a relaxed state and the second clamping portions are close to the corresponding first clamping portions, and a second position where the second clamping portions are further from the respective first clamping portions and the torsional spring member applies a torsional returning force on the first barrel and the second barrel to force the first clamping portions to move toward the corresponding second clamping portions.