GB277506A - Improvements relating to automatically closed hydraulic valves - Google Patents

Abstract

277,506. Boving &. Co., Ltd., and Cook, H. D. Oct. 4, 1926. Safety cut-off valves.- A valve device adapted to close automatically in the event of an abnormal flow, of the kind comprising a butterfly valve held in the open position by a catch released by a falling weight itself released by a catch actuated by a paddle in the main conduit, is provided with means whereby the opening or closing movement of the main valve resets the catch mechanism. The control paddle d is carried by a spindle d<2> mounted in bearings in the bye-pass conduit c and is provided with a weighted lever e having a claw e<1> adapted to engage a lug f<1> on a weighted lever f freely pivoted on a spindle g. The boss of the lever f has a shoulder f<2> adapted when the lever falls to engage a corresponding shoulder h<1> on the catch h and disengage it from the sector i secured to the valve spindle b<1>. The sector i is provided with a segmental sheave i<1> wrapped by a wire rope connected to the valve-closing weight and with a second smaller segmental sheave wrapped by a wire rope connected to the piston l of a dashpot l<1>. The sector i is formed with cam surfaces m<1>, m<2> adapted to engage a roller n on an extension of the lever f to reset the catches as the main valve moves to its open or closed position. The main valve is re-opened by means of an auxiliary pump adapted to restore the liquid to the top of the dash-pot piston, during this operation a valve in the leakage passage is closed by a Bowden-wire mechanism actuated by a grip lever q<1> on the pump actuating lever q. This valve may be actuated directly by a treadle mechanism. A remote control for the device comprises an electric solenoid s adapted to actuate a catch t to release a weighted lever u connected. by a slotted link v to the catch lever e.