GB537372A - Improvements in or relating to hydraulic control valves - Google Patents

Abstract

537,372. Hydraulic control valves. BRITISH THERMOSTAT CO., Ltd., and HURST, W. F. F. MARTIN-. Sept. 18,1939, No. 26068. [Class 135] Hydraulic control apparatus includes a main valve 3 which is electrically actuated to control the flow of pressure fluid to pistons 46, 57, actuating valve members 44, 53, respectively controlling the flow of pressure fluid to one end of a hydraulic ram cylinder 66 or other hydraulic device. The valve members 44, 53 are spring urged to the right, Fig. 5, and control valve closure members 43, 52, 56. The valve member 3 comprises a rod carrying ball valves 2, 24, and is held in the position shown by spring means so that the valve 24 is open and valve 2 closed. Both pistons 46, 57, are thus subjected to exhaust pressure through the pipes 60, 30, 34 so that the left-hand end of the cylinder 65 is opened to fluid pressure via chamber 49, and pipe 67, and the right-hand end thereof is subjected to exhaust pressure via chamber 55 and pipe 68. Upon energization of a solenoid acting on an armature associated with the valve rod the latter is raised to open valve 2 and close' valve 24. Pressure fluid is then led to the pistons 46, 57, by way of casings 38, 37, and pipe 60 and the valve members 44, 53 are moved to the left to open up the passages 49, 67 to exhaust and 55, 68 to pressure fluid and so reverse the movement of the hydraulic piston 65. The apparatus may be used on aircraft for the automatic operation of devices controlling the admission and circulation of heated air, the temperature of which actuates a thermal device which energizes or de-energizes the electromagnetic device of the main valve 3.