Patent GB-893714-A (GB)
Title: An improved fluid flow control valve device
IPC: F15B13/06
Filed: 1960-09-15
Abstract: 893,714. Valves. WESTINGHOUSE AIR BRAKE CO. Sept. 15, 1960 [Sept. 17, 1959], No. 31760/60. Class 135. A valve device comprises a valve body 2 having a part-spherical surface and a valve operating shaft 59 projecting from a pivot point 60 through an opening 23 in the surface, and biased to a normal unoperated position, and a slider 73 movable between two positions, in one of which, retaining means 70, 71, 75 on the spherical surface and the slider are arranged to co-operate when the shaft is moved to an operated position causing actuation of one or more valve mechanisms 16, 17, to retain the shaft in that operated position against its bias to the normal unoperated position, such cooperation of the retaining means being prevented when the slider is in the other of the two positions. The slider 73 is connected to the shaft 79 by a pin 78 in the shaft engaging in one or other of slots 76, 77, Fig. 4, formed in a boss 73 integral with the slider; the slider is formed with a groove 75 provided in a curved surface conforming to the spherical surface of the body 2. In operation, when the shaft is moved to the left from the position shown in Fig. 1, the arm 66 of an element 65 actuates the valve 16 until, at the extreme position of the shaft, the groove locks into engagement with the projection 70 under the action of a spring 85, the latter exerting a greater force than that of the combined force of the return and regulating springs 21, 36 of the valve so that the shaft is retained in this position after manual force is removed. By rotating the slider through 90 degrees and engaging the slot 76 with the pin 78, the slider is arranged to pass between the projections 70, 71 and thus prevent any locking of the shaft at the end of its stroke; a dust cover 79 is located over the slider. The valve mechanism 16, which is identical to the valve 17, is of the self-lapping type and comprises a closure member 32 secured to a spindle 33 which is rigidly connected to a piston 19, the spindle being adjustably screwed to a sleeve 39 having a shoulder 40 against which a follower 37 is urged by springs 21, 36. The valve 32 co-operates with a seat formed on a member 31 having a closure surface 35 co-operating with a fixed seat 25 separating an inlet chamber 26 from a delivery chamber 24 ; annular members 27, 29 formed as spacers, are made from a sintered material in order to act as filters. In operation, when the shaft is moved to the left, the member 65 acts through a peg 69 and thimble 41 on the follower which thereby moves the valve 32 into contact with the tubular seat of the member 31 thereby cutting off communication between the delivery chamber 24 and exhaust; continued movement of the follower 37 moves the closure surface 35 away from its seat and thereby permits fluid to flow from an inlet 9 through filter 27 into the delivery chamber 24. When the pressure in the chamber 24 reaches a certain pressure determined by the loading of the spring 21 it acts against the piston 19 in order to bring the valve 32 and closure member 35 into the selflapping positions. The self-lapping valves may be converted into non-lapping valves by unscrewing a plug 90, 90 so that they abut the underside of the thimble 41 and thereby provide a solid connection between the valve 32 and thimble 41. The arm 68, Fig. 2, of the member 65 actuates a non-lapping type valve 18, which may be converted to a lapping- type valve by removing the lower end of the piston member 48 in order to provide only a resilient connection between the peg 69 and closure member 51.