Lift limit device for a load lifting mechanism

摘要

A limit device for preventing travel of a hoist lift rope load above a predetermined height. The limit device includes an actuator mounted at a reference position adjacent the hoist lifting rope as it is raised and lowered by a prime mover. A switch is connected in a control circuit for the prime mover to place the prime mover in either a raise-lower mode or a raise-prevent mode. A switch actuating mechanism is connected between the actuator and the switch and is operatively connected to maintain the prime mover in its raise-lower mode when the actuator is in its reference position. A follower is mounted at any desired fixed position on the lift rope for travel therewith. Lifting of a load above a predetermined height will result in the follower contacting the actuator to move it from its reference position and cause the switch to place the prime mover in its raise-prevent mode and stop further lifting of the load.