Deck load hoisting and lowering device - has controller keeping rope taut and is disengaged automatically by mechanism with excessive load detector

摘要

The device hoists and lowers a load between a deck and a surface moving in the vertical direction, having a hoist winch with rope attached to the load. When engaged, an automatic controller for the winch keeps the rope taut when attached to the load on the moving surface. An automatic mechanism (19) disengages the controller (36,37,38). There can be a detector (6) for when the winch is winding in under automatic control and controlling the mechanism. It typically incorporates a signal threshold unit and a weigher for the load when hoisting or lowering. When the weight signal exceeds the threshold the mechanism is operated automatically.