GB1267264A - - Google Patents

Abstract

1,267,264. Winches. HYDRAULIK BRATTVAAG A.S. 7 Jan., 1970 [11 Jan., 1969], No. 802/70. Heading B8B. An hydraulic winch system for slueing a loading boom of a ship's derrick comprises a pair of hydraulically driven guy wire winches 16A, 16B connected to a common source of pressure fluid, the winches having wires 20, 21 engaging the boom from opposite sides and being controlled by valve means whereby when one winch is hauling and the other is paying out, the flow of fluid through the paying out winch is restricted to maintain the wire therefrom taut. Hydraulic fluid from a line 26 is supplied to the winch motors 15A, 15B and returns to a control valve 25 through lines 24A, 24B depending on which winch is selected to pay out, the fluid passing between the motors through a line 29 connected to a discharge line 28, to which fluid returning to the valve 25 is discharged. A reduced winding pressure for both winch motors is obtained simultaneously by a neutral setting of the valve 25, in which the supply is open to discharge from the valve 25 through a throttle valve 27 which reduces the supply pressure. One way back pressure valves 30 in the lines 24A, 24B create a back pressure in the associated motor which is paying out wire whereby a braking action thereof is achieved to hold the wire taut. In a further embodiment, Fig. 3 (not shown), a valve is placed between the control valve and the rest of the circuit to facilitate the driven pay out of one winch whilst the other is held stationary. In a further embodiment, the speed of pay out of each winch motor is limited due to a by-pass valve which prevents the fluid discharging from the paying out winch motor to re-circulate through the motor to prevent the formation of a reduced pressure and hence speeding up of said winch.