GB850031A - Improvements in or relating to a stop valve comprising a screw spindle - Google Patents

Abstract

850,031. Valves. CUPEDO, D. J. Jan. 29, 1958 [Feb. 8, 1957], No. 3017/58. Class 135. A stop valve for remote actuation by pneumatic or hydraulic means, or, as stated, by electromagnetic means, and arranged also for direct manual actuation, comprises a screwed operating spindle 1, Fig. 1, carrying at its lower end the valve closure member (not shown) and which co-operates with a movable nut 4 provided with at least one radial stud 5, this stud being guided in an axially extending slot 7 of a member 6 surrounding the nut, the slot 7 having at its upper end a lateral enlargement 8 into which the stud is moved by the actuating means against the force of a spring (not shown) surrounding the spindle, the nut being constrained in this position to allow the valve to be manually actuated. As shown in Fig. 1, an actuating lever 42 for moving the stud 5 into the enlargement 8 is operated pneumatically or hydraulically through a piston and cylinder device 45, 47. The cylinder 45 may be adjustably mounted with respect to a fixed part 50 of the valve (Fig. 3, not shown). In another modification (Figs. 4 and 5, not shown) the nut 4 itself constitutes an actuating piston coaxial with the valve spindle 1 and to which an actuating fluid pressure is applied. Figs. 6 and 7 show a pneumatic remote control arrangement of the stop valve incorporating the lastmentioned embodiment, and in which the stud 5 is positively locked into the enlargement 8 by the locking and release lever 12 disclosed in prior Specification 822,208. Operating cylinder 65 houses the nut 4 constituting a piston concentric with the valve spindle and this is supplied with pressure through a conduit 69 to raise the stud 5 into the enlargement 8 and open the valve, this movement being assisted by a ramp 70 which provides a stop. In this position the stud 5 is latched into a catch on the lever 12-see Specification 822,208. Closing of the valve is effected through a second piston and cylinder device 33, which actuates the lever 12 to release and move the stud out of the enlargement so that the valve closes under its spring, Selector valves 78, 79, Fig. 7, enable the stop valve to be operated locally through pressure supply conduit 82, or from a remote station through a three position actuating valve 73 having valve opening, valve closing, and vent positions respectively, this valve being supplied through conduit 72. Indication at the remote station of the stop valve open and closed positions is given by a pressure operated indicator 84 actuated through a relay valve 80 which has an operating button 81 co-operating with a flange 25 on the spindle, the valve 80 being supplied from both the supply conduits 72 and 82. The stop valve may have a watertight cover 70a to enable it to be used as a remote control valve in inaccessible positions e.g. underwater.