Patent GB-1458105-A (GB)
Title: Tank filling apparatus employing emergency shutoff valve
IPC: B67D7/48
Filed: 1974-02-14
Abstract: 1458105 Automatic shut-off valve AEROQUIP AG 14 Feb 1974 [6 April 1973] 6737/74 Heading B8T [Also in Divisions F2 and G3] A valve for automatically shutting off the delivery of petrol to a tank when the level of petrol contained within the tank has reached a pre-selected value comprises a ring 50<SP>1</SP> slidably mounted within a nozzle 148 and connected via webs 58 to a shaft 56; the ring and shaft being movable between an open position at which the flow of petrol is unrestricted and a closed position where the ring engages a seal 32 thereby cutting off the petrol flow. Shaft 56 is secured to a support rod 40<SP>1</SP> axially movable within a sleeve 26<SP>1</SP> threaded to a ring member 34, both sleeve and ring member being threaded to a spider 20<SP>1</SP> fixed to the valve wall 138 by means of webs 24. A piston 64<SP>1</SP> in an annular chamber 68<SP>1</SP> is held in contact with the roof of the chamber by a helical spring 80, in which position it holds three detent balls 38<SP>1</SP> in engagement with an annular groove 62 in the support rod 40<SP>1</SP> thereby holding the support rod and the ring 50<SP>1</SP> in the open position. The flow of petrol acts upon an annular slot 72 formed between spider 20<SP>1</SP> and a disc 70<SP>1</SP> to produce a Venturi effect within chamber 68<SP>1</SP>, the resulting fall in pressure within the chamber being compensated by an inflow of air through a passage 82 which may be connected via a flexible conduit 108 to a level detecting device. On the petrol within the tank reaching the maximum required level, the flow of air into chamber 68<SP>1</SP> ceases, the resultant drop in pressure drawing piston 641 downward, to release detent balls 38<SP>1</SP> from annular groove 62 in support shaft 40<SP>1</SP> which together with ring 50<SP>1</SP> descends under the action of the flowing liquid into the closed position. A vented chamber 86 serves to cushion the motion of the ring 50<SP>1</SP> to reduce damage to seal 32. The valve may be reset for a subsequent delivery by a lever 441. The level detecting device (Fig. 6) may consist of two members 110, 116 threadedly attached and resiliently held relative to each other so that communication between vents 114, 120 is obstructed by a ball valve 126 thereby preventing the inflow of air and shutting off the delivery valve. In order to fill the tank, the two members 110, 116 are rotated relative to each other into an open position where ball valve 126 no longer obstructs the air flow; the device may then be placed on the tank rim 136, an arm 132 which abuts rim 136 holding the device in the open position. The delivery valve will then be shut off as described, when the air flow is obstructed by petrol within the tank reaching the level of the lower end 122 of member 116. The delivery valve may be connected in series to a variable flow valve 140, the purpose of which is to supply petrol at a slow rate until it has reached a pre-selected level, and at a higher rate thereafter. The flow of petrol produces a Venturi effect in a chamber 182, the fall in pressure being compensated by an inflow of air through a vent 192 which communicates via a tube 194 to a level sensitive device comprising a floatable ball which seals the lower end of tube 194 when the petrol within the tank has risen to a pre-selected level. The resulting pressure fall in chamber 182 displaces seal 186 and reduces the pressure above an annular piston 170 which is then forced upward by the pressure of liquid below thereby opening side channels which allow a greatly increased petrol flow into the tank.