GB735364A - Improvements in or relating to liquid dispensing apparatus - Google Patents

Abstract

735,364. Fluid-pressure servomotor-control systems. AVERY-HARDOLL, Ltd. March 29, 1954 [March 30, 1953; July 1, 1953], Nos. 8746/53 and 18266/53. Class 135. A hosecock for a liquid dispensing apparatus comprises a main valve 17 coacting with a seat 18 between an inlet 12 and an outlet nozzle 14, a pilot valve 24 actuated by a hand-lever 15 coacting with a lever 61, and an auxiliary pilot valve 34 operable by suction due to the stoppage of a flow of air when an air opening 41 is submerged by the rising level of liquid in a tank being filled whereby to cause closure of the main valve. Inlet pressure has access through a small opening 56 to a chamber 21 where it acts on the main valve in the closing direction. When the lever 15 is operated to open the pilot valve 24 the pressure in chamber 21 is released through a port 23, moving the valve 34 against its loading spring 38. The pressure liquid so released then escapes to the nozzle 14 through ports 32, and the main valve is opened, to an extent determined by the degree of opening of the pilot valve 24, by inlet pressure acting on an annular area of the valve surrounding a sealing ring 27. Some of the liquid discharged passes through ports 44 to an annular passage formed between a venturi 28 and a pipe 39 thereby inducing a flow of air from the opening 41 to the pipe 39 and thence through a ribbed, annular passage between a member 37 and the pipe 39 to the throat of the venturi. When the opening 41 becomes submerged the venturi causes a suction to be applied behind the valve 34 to cause the latter to move fully to the left to close the ports 32 and cut-off the escape from the chamber 21 thereby causing the main valve to close.