| 摘要 |
<p>1,183,884. Valves. RACINE HYDRAULICS Inc. 3 May, 1968 [22 Aug., 1967], No. 21132/68. Heading F2V. A main spool 17 is controlled by a pair of pilot spools located at opposite ends thereof and controlled, in turn, by low-pressure signals. Each pilot spool 67 (Fig. 3) has an inlet 62 or 70, exhaust 63 and a port 65 leading to a pilot chamber at the adjacent end of main spool 17. Extensions 110, 118 of each pilot spool carry control diaphragms 94, 98 and isolating diaphragms 100, 101, the chambers to the left and right respectively of the latter being interconnected by passages 140 and communicating with exhaust through restriction (141). The inlets 62, 70 receive fluid from high-pressure inlet 23 via passages 39, 40 in pressure-regulating spool 24 and passages 69, 68. The exhaust ports 63 also communicate via passage 73 with spring chamber 42 of the pressure-reducing valve. Leftward movement of a pilot spool is achieved by applying a signal to the right-hand control diaphragm. Subsequent return of the spool to vent the main spool chamber is achieved by applying the signal to the left-hand control diaphragm. Pins 170, 171 allow manual control.</p> |
