GB682026A - Improved valve - Google Patents

Abstract

682,026. Manually and mechanically actuated valves. WINFREE, R. W. July 31, 1950, No. 19018/50. Class 135. In a valve which includes a closure member movable under manual control towards and away from its seat, a device in the valve housing comes into action when the closure member has been manually approached to a predetermined distance from its seat and releases the closure member from manual control so that it continues its closing movement under the control of a resilient member. In an embodiment, the valve 21, Fig. 1, is urged by a spring 18 towards the closed position. The upper end of the stem of the valve is provided with a stepped surface 28 which, when the valve is open, is forced by the spring 18 into engagement with a similar stepped surface 30 carried by a rotary screwed cap 8. Keys 15 formed on the upper part of the valve stem engage in corresponding grooves in the valve casing and allow the stem to execute only a longitudinal movement. As the cap 8 is rotated in the direction to permit the valve to close, the stepped surfaces 28, 30 will first be in sliding and abutting relation but, when the surface 30 slides off the surface 28, the connection between the two parts of the stem will be broken and the valve will be projected by spring 18 into the closed position. In another embodiment, the two parts of the valve stem 53, 70, Fig. 8, are connected by a swivel pin 56 which allows a small amount of lost motion between them. The lower part 70 carries a rigid projection 69 which, as the valve approaches the closed position, engages a spring-loaded projection 66 in a casing fixed in position in the valve housing. The friction between the two projections is sufficient to arrest the movement of the part 70 until the lost-motion between the two parts of the stem has been taken up. Projection 69 will then be forced past projection 66 and the valve loading spring will complete the movement of the valve to the closed position. In a modification, the two projections are replaced by a pivoted latch which momentarily disconnects the manual drive and allows the valve loading spring to act.