Patent ID: 7156374

Claim:
A chain block comprising a load sheave winding up a load chain having a load attached thereto, a hand wheel that is arranged on one side of the load sheave and rotatable in one of a normal direction and a reverse direction in response to the manual operation of a hand chain, a pinion shaft that is inserted through the load sheave along the center axis of the load sheave in a manner that allows the load sheave to be freely rotatable thereabout, one end of the pinion shaft screwed into the center of the hand wheel and the other end of the pinion shaft including a spindle gear, a reduction gear composed of a small-diameter gear and a large-diameter gear in a unitary body, the large-diameter gear in meshing engagement with the spindle gear, a main shaft gear, in meshing engagement with the small-diameter gear, transferring a torque of the reduction gear to the load sheave, wherein when the hand wheel is rotated in a load lowering direction with the load sheave in no-load condition, the pinion shaft moves in the direction of axis in response to the rotation of the hand wheel until the pinion gear is disengaged from the reduction gear.