GB929735A - Automatic nozzle shut-off device - Google Patents

Abstract

929,735. Valves. SYMINGTON WAYNE CORPORATION. May 17, 1961 [May 31, 1960], No. 17952/61. Class 135. A dispensing nozzle includes a main valve 14, an operating lever 18 which can be held open by a clip 20 and is pivoted to a support rod 22, an outer diaphragm 42 within a chamber 28 to form a sealed space 46, a link 48 coupling the outer diaphragm to a latching means 32 for the support rod 22, an inner diaphragm 76 also attached to the latching means, resilient means to bias the main valve 14 and to force the support rod away from the latching means, a conduit 68 connecting the passageway 16 upstream of the main valve with the sealed space 46 so that the latching means is maintained in engagement when fluid is supplied through the passageway at a predetermined pressure, a Venturi passageway 82 connecting the space between the diaphragms 42 and 76 to a portion of the passageway downstream of the main valve 14, and a conduit 86 to create a reduced pressure in the space when the open end of the conduit is submerged whereby the latching means is disengaged to allow the main valve to close, a slotted member 38 permitting the main valve to be closed by either submerging the nozzle tip or by absence of sufficient pressure in the passageway upstream of the main valve. If the pressure in passageway 16 falls below the predetermined minimum, spring 58 forces diaphragm 42 upwardly to disengage the latching means 32 and prevent the valve from being opened so that accidental discharge is prevented when the supply is restored. The latching means includes a cone-shaped portion 33 which forces locking balls 34 over a shoulder on the support rod. A check valve 74 closes at a lower pressure than the predetermined minimum for operating the diaphragm 42.