US Patent 10112810 Lifting hoist with hysteresis clutch

A lifting hoist (10) having a drive train (14) containing a slip clutch arrangement (23) with a hysteresis clutch (26). The drive train (14) transfers torque, friction-free, in both forward and backward directions of movement between the motor (15) and a gearing (16). The hysteresis clutch (23) forms an unbranched torque transmission path between the motor (15) and the gearing (16). The hysteresis clutch (26) acts as a vibration damper, allows controlled emergency load lowering, and acts as a secure torque limiter in emergency malfunctions when lowering a load. It further can be used as a load indicator by reducing the load-lifting speed before the nominal load is reached or in the event of an overload.