GB831611A - Improvements in valve apparatus for the control of fluids - Google Patents

Abstract

831,611. Valves; fluid-pressure servomotorcontrol systems. FRANCAIS ETAT. May 8, 1956 [May 13, 1955], No. 14281/56. Class 135. A valve consisting of relatively movable parts with passages that may be brought into communication with each other has at least one O-ring of flexible material mounted in one of said parts and positioned so that a portion of it passes over the opening to the fluid passage in the other part, the opening consisting of ports that are elongated in the direction of movement of the O-ring and are of a width no greater than the diameter of the cross-section of the O-ring. In one embodiment a slidable closure member 2 (Figs. 1, 2) is movable to an upper position in which a reduced portion 5 interconnects an inlet 3 and outlet 4, the inlet 3 containing a tubular insert 9 formed with ribs 8 to provide ports that are elongated in the direction of movement of an O-ring 6 carried by the member 2. Additional O-rings 7, 15 are also carried by the member 2. The insert 9 is secured by screws 10. In a modification the movable member 2 is provided with an oblique passageway instead of the reduced portion 5 for interconnecting the inlet and outlet which may be at right angles to the axis of the member 2 as in Fig. 1 or arranged to be coaxial with the oblique passageway through the member 2 when the latter is in the open position. The upper end of the movable member may be connected to an operating lever whilst the lower end may be subjected to a fluid pressure for operating the valve against the force of a loading spring. A further embodiment of the invention consists of a rotary, cylindrical plug valve of which the plug 2, Fig. 3, has a passageway 11 for interconnecting the inlet 3 and outlet 4, and a groove 12 containing an O-ring 6 for surrounding the inlet 3 when the valve is closed. An insert 9 has ribs 8 to provide ports that are elongated in the direction of movement of that part of the ring 6 that sweeps over the inlet port. A further embodiment of the invention comprises a pressure regulating valve consisting of a movable member 2, Fig. 8, loaded by an adjustable spring 29 to a position in which a passage 27 communicates with the inlet 3. The passage 27 communicates with the outlet 4 through passages 28, and increase of outlet pressure raises the movable member 2 against its spring to cause an O-ring 6 to pass over a single elongated slot at the inner end of the inlet 3. Fig. 10 illustrates the application of the invention to a valve in a positional control servo system, the movable valve member 2 being housed in a sleeve 1 which is connected to the movable part 68 of a servomotor controlled by the valve. The movable member 2 is provided with lands having O-rings 36, 37, 40, 41 with coact with elongated ports 33, 34, 35 in the sleeve 1. The ports 33 communicate with a pressure fluid supply 65 whilst the ports 34, 35 communicate with either end of the servomotor 60. Other lands on the movable member 2 and also on the exterior of the sleeve 1 are fitted with O-rings but these do not pass over ports. Pressure fluid exhaust ports 66, 67 are provided in the outer casing C. A certain deflection of the member 2 in either direction results in a corresponding movement of the member 68 of the servomotor due to the connection of the latter with the sleeve 1. It is stated that the elongated port or ports may be provided on the movable member and the O-ring or rings on the fixed member.