Fluid operated brakes and reversing clutches for winch drums

An operating mechanism for a double-drum winch which comprises:

• a. a pump for pumping hydraulic oil from a source thereof into a hydraulic oil supply circuit of the mechanism,
• b. low and high speed clutches capable of being hydraulically engaged to transmit power from a power source and being disengaged by the action of spring means provided respectively therein,
• c. a speed selecting control valve situated between said hydraulic oil supply circuit and a return circuit of said hydraulic oil and capable of selectively permitting hydraulic communication between one of said low and high speed clutches and said pump,
• d. a hook hoisting rotary clutch connected to said low and high speed clutches and capable of being hydraulically engaged to hoist the hook and being disengaged by the action of spring means provided therein,
• e. a hook dropping rotary clutch connected to said low and high speed clutches and capable of being hydraulically engaged to drop the hook and being disengaged by the action of spring means provided therein,
• f. a boom upward swinging rotary clutch connected to said low and high speed clutches and capable of being hydraulically engaged to swing the boom upward and being disengaged by the action of spring means provided therein,
• g. a boom downward swinging rotary clutch connected to said low and high speed clutches and capable of being hydraulically engaged to swing the boom downward and being disengaged by the action of spring means provided therein,
• h. a hook brake having a brake shaft and connected through a one-way clutch to said hook dropping rotary clutch,
• i. a boom brake having a brake shaft and connected through a one-way clutch to said boom downward swinging rotary clutch,
• j. hydraulically operated variable control valves situated between said hydraulic oil supply circuit and said return circuit in the vicinity of the respective rotary clutch and capable of selectively permitting hydraulic communication between said respective rotary clutch and said pump,
• k. a relief circuit situated between said hydraulic oil supply circuit and said return circuit, both the circuits being located between said speed selecting control valve and said pump, and provided therein with a pressure regulator valve to maintain the hydraulic oil pressure supplied into one of said low and high speed clutches at a predetermined constant value, wherein said low and high speed clutches and said rotary clutches are permitted to hydraulically communicate with said return circuit respectively through said speed selecting control valve and said hydraulically operated variable control valves when said clutches are not operated.