Closure member for the fuel tank of an automotive vehicle

A closure mechanism for a tank, the mechanism comprising a cap housing, a locking tube associated with the cap housing so as to be rotatable relative thereto, a cap means disposed opposite the cap housing and associated with the locking tube, a pressure plate associated with the locking tube, means for selectively connecting the cap housing with the locking tube so as to enable the locking tube to rotate with the cap housing, and a clamping ring means associated with the locking tube so as to be rotatable therewith and to enable a locking and unlocking of the closure mechanism on a filler opening of the tank, characterized in that the locking tube and pressure plate are formed as two separate members, the pressure plate surrounds the locking tube and is mounted thereon with a sliding fit, and in that sealing means are provided for sealing separating surfaces between the locking tube and the pressure plate, said closure mechanism allowing said locking and unlocking on the filler opening of the tank without movement of said pressure plate with said locking tube being necessary.