Patent ID: 6923224

Claim:
A filler neck closure assembly for a vehicle fuel tank filler neck, the assembly comprising a housing adapted to be coupled to a fuel tank filler neck to receive a fuel-dispensing pump nozzle during fuel tank refueling, the housing including a top wall formed to include an outer nozzle-receiving aperture, a bottom wall formed to include an inner nozzle-receiving aperture adapted to open into the fuel tank filler neck when the housing is coupled to the fuel tank filler neck, and a side wall arranged to extend between the top and bottom walls to define an interior region of the housing, the housing including an outer closure mounted for movement relative to the top wall to open and close the outer nozzle-receiving aperture and a flapper door mounted for movement relative to the bottom wall to open and close the inner nozzle-receiving aperture, the housing further including a vent passage having an outer end opening into the interior region and an inner end adapted to open into the fuel tank filler neck when the housing is coupled to the fuel tank filler neck, a partition arranged to divide the interior region of the housing into an outer and inner vent chamber, the outer vent chamber communicating with the outer and inner nozzle-receiving apertures and defining a pump nozzle-receiving passageway adapted to receive the pump nozzle therein during movement of a pump nozzle through the outer and inner nozzle-receiving apertures to move the outer closure and flapper door to opened positions during fuel tank refueling, the inner vent chamber communicating with the vent passage, the partition is formed to include a vent channel to place the outer and inner vent chambers in fluid communication, the housing being formed to include a vent port to admit ambient air outside of the housing into the outer vent chamber when the outer closure and flapper door have been moved to closed positions, and a flow control valve assembly yieldably biased normally to close the vent passage to regulate flow of a gas through the vent passage.