| 摘要 |
<p>The system includes a plurality of two-position control valves (26, 30, 36, 40), each controlling fluid flow into and out of a corresponding one of a plurality of hydraulic load devices (14, 16, 18, 20). First and second pressure responsive servo actuators (50 and 52) associated with each control valve operate to move each control valve to first and second positions, respectively. A two-position, solenoid-operated reset valve (56) controls fluid flow into and out of a pilot circuit (54). The pilot circuit communications fluid to and from the second servo actuator (52) of each control valve and to and from a plurality of two-position solenoid-operated, pilot valves (64, 66, 68, 70). Each pilot valve controls fluid flow into and out of the first servo actuator (50) of a corresponding one of the control valves. A detent mechanism (48) holds each control valve in either its first or its second position in the absence of fluid pressure in the servo actuators. A particular hydraulic function may be actuated by momentary energization of particular solenoids of the reset and/or the pilot valves. The first actuators (50) are larger than the second actuators (52) so that pulsing the reset valve and a pilot valve simultaneously sets the control valve corresponding to the selected pilot valve and resets any other control valve.</p> |
