| 摘要 |
<p>922,644. Fluid-pressure servomotor control systems; valves. C. A. NORGREN CO. Nov. 2, 1961 [March 20, 1961], No. 39253/61. Class 135. Fluid flow from an inlet 16 to an outlet 21 is controlled by a closure member 26 attached to tube 28, the member 26 being urged on to a resilient slot 25 by a combined resilient and sealing element 27. The position of the member 26 is determined by a diaphragm 63 having a control disc 64 abutting and closing the upper end of the tube 28; the position of the diaphragm 63 depends upon the pressure in a chamber 60 that is controlled by a pilot valve 47 which determines the fluid flow from the inlet 16 via passages 34, 35, 54 and an adjustable porous bleed 55 to atmosphere; the underside of the diaphragm is subjected to outlet pressure. The passage 54 is open to the chamber 60. The pilot valve 47 is actuated by an adjustably spring-loaded diaphragm 74, the chamber 71 of which is connected to the outlet 21 by a passage 70. If, as a result of an outlet pressure greater than that required, the member 26 seats before the required pressure is attained, the diaphragm 63 continues to rise and lifts the disc 64 from the tube 28 whereby outlet fluid escapes to atmosphere through the latter. Similarly, a pressure surge downstream of the valve will cause the same relief action by acting directly on the diaphragm 62.</p> |
