GB995515A - Valves for controlling fluid flow - Google Patents

Abstract

995,515. Valves. NEW YORK AIR BRAKE CO. Sept. 13, 1963 [Dec. 20, 1962; March 21, 1963], No. 36145/63. Heading F2V. A valve includes a housing 11 containing a through valve bore 12 and a generally C-shaped exhaust chamber having a body portion 35 parallel with and spaced from the valve bore and two leg portions 24, 24<SP>1</SP> intersecting the bore at opposite ends, a first passage 37 extending through an internal wall between the bore 12 and the portion 35 and a second passage 38 extending into the housing from its outside surface, valve means 41 extending across the portion 35 to transmit to the second passage all of the fluid flowing through the first passage when the rate of flow is below a predetermined value and, when the rate of flow is above this value, to divert the balance of the flow above the predetermined rate into the exhaust chamber. The valve means comprises a sleeve containing a spring-loaded closure 46 which controls ports 43, 44 and has its position determined by the pressure drop across an orifice 47. A valve 21 slidably mounted in the bore 12 has three lands 29, 31, 32 which isolate the valve means from a supply port 22 when the valve 21 is moved to left or right to connect a motor port 14 through ports 33, 34 and a non-return valve within the valve 21 to supply an exhaust. A relief valve 26 is also provided. In Fig. 3, the closure member 45a is slidably mounted in the passages themselves and is provided with ports 44a for communication with the body portion of the exhaust chamber. The port 18 in the embodiment of Fig. 1 is blind and the valve controls a single-acting motor but it may be used in conjunction with a further set of ports in the valve 21 to control a double-acting motor.