Steam-driven tow line winch

Claim 1

In a winch system of the type including a tow line winch actuated by a steam-driven motor, a live steam line for supplying steam for operating the motor, an exhaust line, and a hunting valve for controlling the direction of steam flow from the live steam line through the motor to the exhaust line and thereby controlling the direction of operation of the winch, the improvement comprising: a pilot operated pressure control valve having a pilot port and connected between the live steam line and the inlet port of the hunting valve; a pilot line connecting the working pressure of the steam-driven motor to the pilot port of the pressure control valve and thereby actuating the pressure control valve toward a first position; a three-way cock in said pilot line having one position for connecting the working pressure of the motor to the pilot port and another position for connecting the working pressure of the motor to said exhaust line whereby the pressure control valve is put out of operation; and means for applying a predetermined bias to the pressure control valve and thereby actuating the pressure control valve toward a second position; so that the flow of steam from the live steam line through the pressure control valve to the hunting valve depends upon the ratio between the working pressure of the steam-driven tow line winch and the predetermined bias.