Abstract: The closure includes a base adapted to be screwed into a fuel tank filler pipe and having a fill opening normally closed by a hinged flapper which is opened when a fuel nozzle is inserted into the fill opening. The base is shielded against being manually gripped and unscrewed from the filler pipe by a cover also having a fill opening and normally supported for free rotation on the base so that turning of the cover normally is ineffective to unscrew the base. When a key is inserted into the cover, it couples the cover and the base for rotation as a unit and thereby enables the base to be unscrewed from the filler pipe. The same key also is used to actuate a locking device for locking the flapper in its closed position.

Abstract: A hinged flapper valve is mounted to swing between open and closed positions with respect to a fill opening formed through a base mounted in the outer end portion of a motor vehicle fuel tank filler pipe, the flapper being swung to its open position as an incident to insertion of a fuel nozzle into the filler pipe. A locking ring is rotatably supported on the base for turning between locked and unlocked positions and, when in its unlocked position, frees the flapper to swing to its open position. When the locking ring is turned to its locked position, it draws the flapper into tight engagement with the base to seal the fill opening therein and to hold the flapper securely closed. Turning of the locking ring between its locked and unlocked positions may be effected automatically by a motor adapted to be controlled from inside the vehicle.