OVER-WINDING ALARMING METHOD AND DEVICE FOR WIRE ROPE OF PIPE LAYER

PROBLEM TO BE SOLVED: To prevent an erroneous alarm of an over-wind alarming device for a hook hoist wire rope of a pipe layer. SOLUTION: An over-wind alarm is emitted when an over-wind of a wire rope is sensed only during the boom lowering operation or hook raising operation. After sensing of over-wind, the emission of the over-wind alarm is continued until over-wind is no more sensed. A parallel circuitry formed from a boom lowering sensing switch 43 to be actuated when the boom is lowered and a hook raising sensing switch 44 actuated when the hook is raised and an over- wind switch 32 of an over-wind sensing means 20 actuated when an over-wind is sensed are connected in series to an alarming means 42.