GB563896A - Improvements relating to gate valves - Google Patents

Abstract

563,896. Valves. SEAMARK, L. M. C. March 26, 1942, No. 4011. [Class 135] A gate valve actuated by a rotary spindle has a resilient valve member divided parallel to its axis and provided with threads or ridges preferably of buttress cross-section engaging corresponding recesses and threads or ridges on an actuating member. When the spindle is moved to close the valve, engaging surfaces of the threads and grooves which are set at an inclination to the axis of the spindle ride one on the other to jamb the valve in its seat. As shown in the Figure, the gate comprises a cylindrical plug 1 divided longitudinally at 2 and held against rotation by a groove 11 engaging a pin 12. A threaded plug 9 engages a threaded bore in the gate and has a squarethreaded aperture engaging a threaded actuating spindle 18. The spindle is held against axial movement by a collar 24 held between thrust rings 23 by a screwed ferrule 25. The plug 9 is held against rotation by pins 14 engaging recesses in the gate and plug and held in place by a spring ring 15 engaging a groove in the plug. The gate may have sealing ridges adapted to contact the removable cover 20 or the ferrule 25 when the valve is fully open to facilitate repacking the stuffing-box 26. To hold the gate in the closed position while permitting the removal of the actuating spindle and cover, a threaded retaining screw is inserted through an aperture normally closed by a plug 32 and screwed into a threaded socket 7 in the lower end of the gate. The lower end of the groove 11 may move into engagement with a fixed tapered expanding plug secured to the casing. The buttress threads may be formed in the valve spindle which may also be arranged to rise and fall. When applied to a sluice valve having a gate comprising flat valve plates joined by plate springs, the backs of the plates are formed with a series of grooves and ridges engaging similar grooves and ridges on the actuating plug. According to the Provisional Specification, the plates may be resilient and slightly curved in the direction transverse to the direction of movement and joined together by wire springs engaging recesses in the edges of the plates. Further, the plug 9 may have a peripheral flange with lugs engaging grooves in the casing. Also, the upper end of the gate may be slotted to receive downwardly projecting lugs formed on a disc slotted radially so that it becomes V-shaped. The arms of the disc are engaged with the flat faces of oppositely disposed recesses provided below the peripheral flange on the body of the plug.