Patent GB-758253-A (GB)
Title: Improvements in and modifications of fluid valves
IPC: F16K29/00
Filed: 1953-07-08
Abstract: 758,253. Valves. HOLMES & CO., Ltd., W. C., and INGHAM, C. July 6, 1954 [July 8, 1953], No. 18892/53. Class 135. In a gas valve of the double-faced type in which two valve discs 1 with annular sealing faces 6 are mounted on bosses 2 cast on levers or slippers 3 supported for relative pivotal movement within a central yoke 4 which also supports a removable nut 51 running on a threaded spindle 36 rotatably mounted in a bonnet 37 attached to the valve casing and in which a conical wedge piece 23 at the base of the valve cooperate with the ends of the levers 3 when the valve is in the closed position, the valve discs are pressed against sealing faces 7 in the valve casing 8 by spring means 9 which act on the levers or slippers 3 so that the effective pressure is applied centrally to the discs through the bosses 2. The spring means comprise leaf springs 9 held against transverse movement by slots 10 in the slippers and against longitudinal movement by flanges 11 on cam-shaped castings 12, 13. The casting 12 has a tapered bore 15 separated by a shoulder 21 from rectangular opening 16 which embraces a boss 18 integral with the yoke 4. The boss 18 has at its outer end a rectangular extension 20 over which the opening 16 will pass when the casting is turned through 90 degrees from the position shown in Fig. 3.. This releases the casing 12 and due to the non-circular shape of the latter also releases the tension on the springs 9 which can thus be removed or replaced through the slots 10. The valve casing has removable covers such as 66 to facilitate access to the mechanism. The casing 13 may be detachable like the casting 12, but preferably is solid and integral with the yoke 4. The valve discs move over guides 65 which are inclined to a plane passing through the axis of the spindle 36 and at right angles to the disc facings 6. The wedge-piece 23 has a threaded portion 24 by which it is adjustably supported in a flanged sleeve 25 bolted to the bottom of the valve casing. The wedge-piece is locked in its adjusted position by a short stem 32 of rectangular or other non-circular section co-operating with a hole of similar section in the base of the wedge-piece. The stem 32 is integral with a plate 33 bolted to the sleeve 25. Lubricant or anti-corrosive fluid is supplied to a chamber 53 below the nut 51 when the valve is in the fully open position by means of a tube 50 which opens at its upper end into a recess 47 surrounding the thrust collar 38. The recess 47 is supplied through a further tubular member 49 bearing an inlet valve 48 at its outer end. The bonnet 37 is surmounted by an apertured cover 41 which provides a stuffing box 41a. The cover is secured by bolts 46 which also clamp a gland 43 in position. A threaded part 59 of the spindle of smaller pitch than the square thread 52 supports a nut 60 with a pointer arm passing out through a slot in cover 41 and serving as an indicator of the position of the discs 1. The upper spindle bearing 55 is lubricated through a passage 57 with an inlet fitting 58. In a modification, one of the slippers is integral with the yoke 4, the other being pivoted on the end of the web 5. In this case only one leaf spring 9 is provided and this is held against endwise movement by flanges on two cams rigid with a bar passing through the yoke. A portion of one of the flanges is cut away to facilitate release of the leaf spring when the cams are turned. The threads 52 are lubricated by an inclined bore in the spindle 36 opening into the recess 47. The spindle is also lubricated adjacent the gland 43.