Abstract: A refueling fuel level responsive control valve with a two-stage closing operation providing an initial soft shutoff cue to the filler nozzle operator, and a subsequent final shutoff after a limited amount of “roundoff” filling to a maximum fuel level. The control valve includes two float-operated valve elements which dose serially in response to initial shutoff and final shutoff refueling fuel levels. The initial shutoff partially closes the control valve to create a temporary shutoff-inducing increase in fuel tank pressure. Final shutoff occurs after allowing a few round-off “clicks” of the filler nozzle to fully close venting through the control valve.

Abstract: An onboard vapor recovery system for a vehicle fuel system having a fuel tank, a filler neck dynamically sealed by high pressure fuel flow from a filler nozzle, and a vapor recovery apparatus such as a carbon canister. The system includes a liquid level operated control valve which shuts off refueling with a two-stage closing operation providing an initial soft shutoff and a final shutoff. The system also preferably includes a valve in the fuel tank to maintain a predetermined pressure head sufficient to hold the system closed against further refueling at least temporarily, and a positive action, one-way check valve in the lower end of the filler pipe to prevent spitback of fuel from the pressurized tank once refueling has ceased.

Abstract: A one-way check valve assembly for use in the filler pipe of a vehicle fuel system to prevent liquid fuel from backing up the filler pipe. The check valve assembly includes a valve member formed from a resilient material, normally biased to a closed position in sealing engagement with the interior surface of the filler pipe flow passage, and forced open during refueling by the flow of fuel through the filler pipe inlet to the fuel tank. In a preferred form the valve member comprises a thin-walled flexible membrane formed in butterfly fashion about a central pivot member in the filler pipe. In an illustrative form the individual wings or sides of the valve member are semi-elliptical and in the closed position are angled downstream from the pivot point, conforming to the filler pipe contour in sealing fashion as angular sections of the flow passage.

Abstract: A weldable vapor vent valve assembly comprising a heat-resistant valve body and a weldable connector portion fastened to an upper end of the valve body for welding onto the outer surface of a polymeric fuel tank. In one embodiment the weldable connector portion is overmolded onto an upper end of the valve body, with the mechanical connection and fluid seal between the weldable connector portion in the valve body strengthened by one or more sets of circumferential anti-leak ribs on the upper end of the valve body. In another embodiment the weldable connector and the valve body are manufactured separately, and the seal and connecting means for assembling the two in a fluid- and vapor-tight manner allow the valve body to be assembled to the weldable connector in a simple axial press-fit.

Abstract: The present invention comprises a rollover vent valve for mounting on a vehicle fuel tank to selectively vent fuel vapor from the fuel tank to a vapor trap such as a carbon canister. The valve includes a liquid fuel responsive control element connected to a valve element via lever arm structure to move the valve element between open and closed venting positions on a valve seat. The mechanical opening advantage obtained with the lever arm structure provides for a powerful peel-away action to ensure opening of the valve despite a tank/canister pressure differential acting to maintain the valve element in the closed position. In one embodiment the lever arm structure includes a hammer-claw mechanism to provide an initial pivotal opening force using the maximum potential of the lever arm, and a subsequent rectilinear opening force.

Abstract: A vapor vent valve for venting air and fuel vapor from vehicle fuel tanks comprises a hollow valve body having radial flow ports formed therein, and an axially slidable shutter movable between a valve open position remote from the radial flow ports and a valve closed position covering the radial flow ports. An axially slidable float mounted on the valve body adjacent the shutter lowers and raises the shutter between the valve open and closed positions in response to changes in the tank fuel level. The axial shutter and float structure is unaffected by the radial outflow of air and fuel vapor through the ports.

Abstract: A high pressure vapor vent valve for automotive fuel tanks is provided with bayonet-insertion, turn-to-lock locking structure mating with an opening in the fuel tank. An O-ring mounted on the valve body provides a fluid-tight radial compression seal between the valve body and the fuel tank wall to prevent leakage of fuel and fuel vapor therebetween. The O-ring radial compression seal is effected independently of the locking structure.