Closure assembly for fuel-tank filler neck

A fuel tank filler apparatus adapted for use in a vehicle fuel system, the fuel tank filler apparatus comprising

• a blow-molded fuel-tank filler neck associated with a fuel tank, the blow-molded fuel-tank filler neck shaped to extend around a central axis of the fuel tank filler apparatus to define a fuel receiving passageway and the blow-molded fuel-tank filler neck including an outer end having a top surface that defines a mouth that opens into the fuel receiving passageway,
• a capless filler neck closure adapted to be mated with the outer end of the blow-molded fuel-tank filler neck to block fuel and fuel vapor from escaping the blow-molded fuel-tank filler neck during use of the fuel tank filler apparatus, the capless filler neck closure including a nozzle-insertion housing that extends into the blow-molded fuel-tank filler neck, an outer dust cover mounted to pivot relative to the nozzle-insertion housing from a closed position arranged to block dust from entering the nozzle-insertion passageway to an open position arranged to allow a fuel nozzle to enter the nozzle-insertion passageway, and an inner closure door spaced apart from the outer dust cover along the central axis and mounted to pivot relative to the nozzle-insertion housing from a closed position arranged to block fuel and fuel vapor from escaping the associated fuel tank and an open position arranged to allow a fuel nozzle to enter fuel receiving passageway, and
• interface means for pushing a portion of the blow-molded fuel-tank filler neck into a round shape in order to facilitate receipt of the capless filler neck closure in the blow-molded fuel-tank filler neck and for coupling the capless filler neck closure to the blow-molded fuel-tank filler neck without welds or permanent attachment to facilitate selective decoupling of the capless filler neck closure from the blow-molded fuel-tank filler neck thereby allowing non-destructive removal of the capless filler neck closure for replacement or repair of the capless filler neck closure, wherein the interface means includes a retainer ring that couples the capless filler neck closure to the blow-molded fuel-tank filler neck, the capless filler neck closure is formed to include a cam slot that extends radially inwardly toward the central axis and away from the retainer ring, and the retainer ring includes an outer band that extends circumferentially around the blow-molded fuel-tank filler neck, a cap wall that extends radially inwardly away from the outer band into the cam slot formed in the capless filler neck closure to couple the retainer ring to the capless filler neck closure, and a crimp tab configured to engage the blow-molded fuel-tank filler neck to couple the retainer ring to the blow-molded fuel-tank filler neck.