GB579466A - Improvements relating to control valves for fluid under pressure - Google Patents

Abstract

579,466. Pressure - regulating valves. WESTINGHOUSE BRAKE & SIGNAL CO., Ltd. April 15, 1944, No. 6983. Convention date, May 27, 1943. [Class 135] A pressure-regulating valve of the selflapping type comprises a pressure supply valve member 24 controlling the supply from a conduit 52 to a conduit 53 and a pressure release valve member 22 controlling the release of pressure past a stem 23 and through passages 36, 35 to atmosphere. The desired pressure in conduit 53 is obtained by a corresponding movement of a lever 43 which acts through a stem 32 on a comparatively strong spring 39 which moves a diaphragm 5, which carries a valve seat 20 for the release valve 22, downwards so as to close this release valve and open the supply valve 24. The pressure which builds up in conduit 53 and chamber 18 acts upon the diaphragm 5, through a restriction 51, to move it back to the neutral position in which both valves are closed and also acts through a passage 8 on another diaphragm 3 which is connected to the operating stem 32. The pressure on this latter diaphragm balances the upward thrust on spring 39 from the lower diaphragm and relieves the actuating lover 43 of strain. Any further movement of lever 43 in either direction causes operation of either of the valves 24 or 22 and a corresponding increase or reduction in the pressure in conduit 53. A friction device comprising a spring-pressed ring 46, Fig. 2, is provided on the spindle 44 of the lever 43 to prevent any unintentional movement of the lever by shock or jarring.