Hoist having worm safety device.

摘要

A hoist having a worm safety device in which the worm (30) is continuously meshed with a worm wheel (26) coupled to the drum (10). The worm (30) is accelerated to a speed greater than that of the worm wheel (26) and at a torque sufficient to overcome the frictional contact between the worm (30) and worm wheel (26) when the hoist direction is reversed.