GB434197A - Valve control system - Google Patents

Abstract

434,197. Hydraulic valve systems; controlling motor vehicles electric switches. SHAND, R. C., 127, Wildwood Gardens, and JURS, A. E., 304, Pacific Street, both in Piedmont, California, U.S.A., (trading as SHAND & JURS CO.). Feb. 19, 1934, No. 5435. [Class 135] [See also Groups XXXI and XXXVII] Relates to a closed hydraulic valve system for discharging liquids from a compartmented tank vehicle, similar to that described in Specification 434,196 and comprising a lift valve in each compartment operated by a hand-actuated pump device acting through a hand-set selector-valve. The selector valve, however, allows the valve of one compartment only to be opened at a time venting the liquid from the other valves, and is locked on actuation of the pump. The pump, Fig. 8, comprises a piston 93 actuated against a spring 144 by a hand lever 98 which is connected to fixed pivots 107, 113 by links 104, 109 and to the piston rod 92 by link 99, by which means the piston remains depressed when actuated, with the handle 98 not detachable. The selector valve, Figs. 8, 9, comprises a plug cock 118 set by a handle 122 to put passage 129 into communication with one of the outlets 127 to the (four) tank valves, the other three valves being vented by groove 131 and passage 133 to the liquid reservoir above the pump piston. The selector valve 118 is locked during discharge from a tank compartment by a projection 143 carried by the pump piston engaging a recess of the crown 141. The valves, Fig. 3, of the tank compartments each comprise a valve ring 24a carried by a moving cylinder 26 co-operating with a stationary piston 28. The pressure liquid from a pump outlet 127 passes by a pipe 19 and passages 48, 31 to the chamber 29<a>, liquid from the tank compartment, after straining at 39, discharging by conduit 16 attached to a casing 41 mounted on the outside of the tank and through which the complete valve may be withdrawn for repairs. Each conduit 16 may be further controlled by a spring-closed lift valve, Fig. 5, which on opening by a hand-operated pinion 76 and rack 77, is normally retained open by a spring catch 79. The catch, however, is mounted on a fusible plug 83 and is released in the event of fire. The ignition circuit of the vehicle motor is broken or short-circuited on actuation of the valve-operating pump, by liquid pressure transmitted through connections 188, 187, Fig. 7, to a metal bellows 176. This bellows, on actuation, lifts contacts 181 from contacts 182 breaking the ignition circuit, or if desired makes contact between contacts 184, 186 short-circuiting the ignition circuit. Fig. 2 (not shown), illustrates a driver's emergency valve, and fusible elements in the pipes 19, for venting the pump pressure so as to close the tank valves. Fig. 17 (not shown), illustrates a vent for the roof of each tank compartment, comprising a loose ball valve which closes if the tank is overturned, associated with a liquid seal and with soft plugs which are blown out by a dangerous pressure or which melt in the event of fire. A modified form of the selector valve shown in Fig. 8 is described, Fig. 13 (not shown), in which the plug cock is arranged at right angles to the pump cylinder. In this form the cock controls eight tank compartments, its outlets being arranged in two planes; the end of the pump piston rod locks the cock by engaging the crown laterally.