GB1136093A - Fluid control valves - Google Patents

Abstract

1,136,093. Valves. ROTAX Ltd. 30 Aug., 1966 [8 July, 1965], No. 28943/65. Heading F2V. [Also in Division G3] A valve controlling the flow from an inlet 12, Fig. 1, to an outlet 13 comprises a valve closure 18 carried by a piston 17 which is subjected to the fluid pressure in chambers 19, 20. The chamber 19 is connected by conduit 22 to the downstream pressure while the chamber 20 has a constant pressure regulated by a valve 24. The valve 18 is thus adjusted with changes in downstream pressure to keep this pressure constant. A second valve 29 is connected to a piston 25 and the chambers 26, 27 on opposite sides of the piston are connected by conduits 32, 33 to control valves 34, 35, Fig. 2, which under normal conditions are in the positions shown whereby the chamber 26 is connected to a pressure supply 39 and the chamber 27 to exhaust through ports 38 so that the valve 29 is open. A piston 50 is loaded by a spring 58 against downstream pressure applied through conduit 51. If the valve 18 sticks say or the downstream pressure rises above a predetermined value for any reason, the pressure causes the piston 50 to depress a plate 45 and actuate the valves 34, 35 to cause closure of the valve 29. Downward movement of the piston 50 to actuate the valves rocks a locking device until a rod 62 engages a notch 65 to hold the piston 50 in its lowermost position. To release the piston 50, a valve 53 is actuated to lower a second piston 49 which carries a spring 57 which, when the valve 53 is again actuated to cause the piston 49 to rise, rocks the lock to release the pin 62 from the notch 65. When the valve is operating normally, the valve 29 may be closed by actuation of the pilot valve 53 when the combined pressures on the pistons 50, 49 actuate the valves 34, 35.