Pulley blockThe pulley block is composed of a fixed pulley and a movable pulley,Website:http://www.xqcranes.com, which is both labor saving and can change the direction of the force.pulley block is by around a central shaft rotating grooved disk and across the disc of the soft cable (rope, tape, wire ropes, chains, etc.) which can rotate around the center shaft to rotate a simple machine. (can be seen as a distortion of the lever)