Hold jar structure tightly

The utility model discloses a hold jar structure tightly, including body and the sleeve inside fixed with the body, be equipped with two vertical symmetrical arrangement's holding piece in the sleeve,the lower extreme of holding piece offsets and can rotate relatively, the internal locking spring that can inwards promote the holding piece that is equipped with of basis, the sleeve is equipped with the piston that can slide from top to bottom in the top of holding piece, and the bottom of piston is equipped with can be protruding with two holding piece outwardly strutting's unblock, be equipped with the step spacing to the piston stroke lower dead center on the telescopic inside wall. The utility model aims at providing an effectively prevent the hold jar structure tightly that the holdingpiece locked. 本实用新型公开了种抱紧缸结构，包括本体以及与本体内部固定的套筒，所述套筒内设有两个竖直对称布置的夹持片，所述夹持片的下端相抵并且可相对转动，所述的本体内设有可向内推动夹持片的锁紧弹簧，所述套筒在夹持片的上方设有可上下滑移的活塞，活塞的底部设有可将两个夹持片向外撑开的解锁凸起，所述套筒的内侧壁上设有对活塞行程下止点限位的台阶。本实用新型旨在提供种有效防止夹持片反锁的抱紧缸结构。