Vapor recovery systems

A refueling vapor recovery system, comprising:

• a liquid fuel tank including a fill tube having an inlet into which a liquid fuel fill nozzle may be inserted for delivery of liquid fuel into said tank, and a removable closure cap for said fill tube;
• a vapor storage means;
• a vapor recovery passageway extending from the fuel tank to a vapor storage means;
• a valve within said vapor recovery passageway, said valve comprising a housing having an interior, a movable wall dividing said interior into first and second fluid chambers, said first fluid chamber including a vapor inlet connected to said vapor recovery passageway, for receiving vapor from the fuel tank, and a vapor outlet connected to said vapor recovery passageway, and through which vapor flows when the outlet is open, from said first chamber to the vapor storage means, and a closure member for the outlet connected to the movable wall, said second fluid chamber including a combined inlet and outlet;
• a signal pressure region in said system which is at a first pressure when the closure cap is on the fill tube and there is vapor pressure within the fuel tank, and is at a lower second pressure when the closure cap is removed from the fill tube;
• and
• a signal pressure passageway interconnected between said signal pressure region and the combined inlet and outlet for the second chamber, said signal pressure passageway communicating pressure from said signal pressure region to the second fluid chamber of the valve;
• and
• wherein when the closure cap is installed on the fill tube and there is vapor pressure within the fuel tank, said signal pressure region and said second fluid chamber are at said first pressure and vapor pressure from the tank is within the first fluid chamber, and the pressures in the first and second fluid chambers acting on the wall positions the wall to in turn position the valve closure member in a position closing the outlet from the first fluid chamber;
• and
• wherein following removal of the closure cap and during introduction of liquid fuel into the fuel tank, the pressure in said signal pressure region and said second chamber drops to the lower second pressure and the pressure in the first and second fluid chambers acting on the wall displaces the wall and moves the valve closure member plug member into a position opening the outlet from the first fluid chamber, allowing vapor within the fuel tank to flow through the vapor recovery passageway to the vapor storage means, with the introduction of liquid fuel into the fuel tank acting to displace vapor from the fuel tank through the vapor recovery passageway to the vapor storage means.

A vehicle, comprising:

• a liquid fuel tank including a fill tube having an inlet into which a liquid fuel nozzle is inserted for delivery of liquid fuel into the said tank, a removable closure cap for said fill tube and, a refueling vapor recovery system, comprising:
• a vapor storage means
• a vapor recovery passageway extending from the fuel tank to the vapor storage means;
• a valve within said vapor recovery passageway, said valve comprising a housing having an interior, a movable wall dividing said interior into first and second fluid chambers, said first fluid chamber including a vapor inlet connected to said vapor recovery passageway, for receiving vapor from the fuel tank, and a vapor outlet connected to said vapor recovery passageway, and through which vapor flows when the outlet is open, from said first chamber to the vapor storage means, and a closure member for the outlet connected to the movable wall, said second fluid chamber including a combined inlet and outlet;
• a signal pressure region in said system which is at a first pressure when the closure cap is on the fill tube and there is vapor pressure within the fuel tank, and is at a lower second pressure when the closure cap is removed from the fuel tank and a fill nozzle is in the fill tube, delivering liquid fuel into the fill tube;
• and
• a signal pressure passageway interconnected between said signal pressure region and the combined inlet and outlet for the second chamber, said signal pressure passageway communicating pressure from said signal pressure region to the second fluid chamber of the valve;
• and
• wherein when the closure cap is installed on the fill tube and there is vapor pressure within the fuel tank, said signal pressure region and said second fluid chamber are at said first pressure and vapor pressure from the tank is within the first fluid chamber, and the pressures in the first and second fluid chambers acting on the movable wall positions the movable wall to in turn position the valve closure member in a position closing the outlet from the first fluid chamber;
• and
• wherein following removal of the closure cap and during introduction of liquid fuel into the fuel tank, the pressure in said signal pressure region and said second chamber drops to the lower second pressure and the pressure in the first and second fluid chambers acting on the movable wall displaces the wall and moves the valve closure member into a position opening the outlet from the first fluid chamber, allowing vapor within the fuel tank to flow through the vapor recovery passageway to the vapor storage means, with the introduction of liquid fuel into the fuel tank acting to displace vapor from the fuel tank through the vapor recovery passageway to the vapor storage means.