GB810198A - Improvements in fluid pressure valves - Google Patents

Abstract

810,198. Valves. DUNLOP RUBBER CO. Ltd. May 1, 1955 [May 19, 1955], No. 14423/55. Addition to 722,468. Class 135. In the solenoid-controlled fluid pressure valve described in the parent Specification, the stationary valve guide for the hollow cylindrical shuttle valve member 14 is replaced by a fluidtight slidable piston 14a integral with the shuttle member 14. The piston carries a sealing ring 11, a lubricating ring 10 and a retaining ring 12 and slides in a chamber 1 having a connection 8 to a source of fluid pressure, and coaxial outlet and relief passages 3, 22. The ends of the member 14 are chamfered to co-operate with a seating ring 5 and an annular sealing washer 13. The latter is retained in an external groove in a tubular member 28 projecting into the member 14 and terminating short of a partition 15 therein when the member 14 seals against the washer 13 to cut off the relief passage 22. The connection 8 communicates through a restricted passage 18 with a chamber 30 above the piston 14a. When the relief valve formed by the upper end of the shuttle member 14 is open the chamber 30 is connected to the passage 22 through radial passages 19. The shuttle member is loaded to close the outlet valve and open the relief valve by a spring 29. The passage 22 is normally closed by a spring-loaded exhaust valve 25 carried by a plunger 24 forming the core of a solenoid 20. On energization of the solenoid, the exhaust valve 25 opens and vents the pressure in the chamber 30 and so that the pressure in the chamber 1 below the piston 14a overcomes the spring 29. The outlet valve therefore opens and the relief valve closes. These valves remain in this position even if the solenoid is deenergized and the exhaust valve closed until the pressure at the source is shut off or substantially reduced.