| 摘要 |
<p>923,040. Fluid-pressure servomotor control systems; valves. PARKER-HANNIFIN CORPORATION. May 9, 1961 [May 16, 1960], No. 16853/61. Class 135. Pump 1, Fig. 1, supplies fluid to two control valve units 6, 11 in series respectively controlling low pressure apparatus 20, 21, and highpressure apparatus 22, 23, the pressure being by-passed to sump when valves 16-19 are in neutral position via inlet chambers 34, 70, by-pass passages 39, hollow plug 40 sealing-off the exhaust chamber 41 in unit 6, connecting pipe 9 and pipe 8, and the pressure building up in chamber 34 on operating valves 16, 17 and in chambers 34, 70 on operating valves 18, 19. The pressure in 34 is normally relieved by a valve 50, Fig. 3, at one pressure, and on operating unit 11, is relieved at a higher pressure, the valve 50 being controlled by piston leak 68 and pilot valve 57 normally loaded by spring 58, the loading of 58 being increased by plunger 61 when it is exposed via 14 to the pressure in pipe 9 increased by operation of unit 11.</p> |
