Fluid pressure-controlled winch mechanism

摘要

A winch drum carrying a cable is supported by drive mechanism which includes a normally disengaged drive input clutch that is engageable in response to pressurized fluid to reel in cable. A normally engaged disconnect clutch disengages in response to fluid pressure to free the drum for rotation independently of the drive mechanism. A normally engaged brake immobilizes the drive mechanism except when released by fluid pressure. A control valve provides for directing pressurized fluid to appropriate ones or combinations of the clutches and brake as necessary to establish any of four operational conditions including Reel-In, Brake-On, Brake-Off and Disconnect modes of operation. A check valve between the flow lines that connect the control valve to the input clutch and to the brake assures that there is no momentary overlapping of engagements of both the input clutch and the brake when the Reel-In mode of operation is initiated or terminated.