| 摘要 |
1528566 Winch braking apparatus CATERPILLAR TRACTOR CO 21 July 1977 [17 Nov 1976] 30698/77 Heading B8B [Also in Division F2] A control for an hydraulically operated winch having an hydraulically disengaged brake 14 and a multispeed hydraulically controlled transmission, comprises a transmission and brake control valve 28 manually controlled by an actuator 30 whereby the transmisison is placed in neutral automatically whenever the brake is to be disengaged. The valve 28 comprises a spring centered spool valve movable by the actuator 30 to select the rate of elevation at a high or low speed. The braking part of the valve 28 includes an inlet supplied either directly from a pump 20 or from an accumulator 62, and an outlet leading to the brake 14 and also to a metering pump 16 driven by the winch drum, the pump acting as a governor for the amount of brake release depending on the drum speed. The spring centred spool of the braking valve incorporates metering slots to graduate the supply of brake release fluid. |
