Abstract: A shut-off valve in a gas line leading to a fuel tank of a motor vehicle, comprising a valve seat and a valve body which is movable by means of the opening and closing movement of a fuel tank lock. In order to provide a valve which opens a large flow cross-section in the open position, it is provided that the valve body comprises a flexible diaphragm which is pretensioned against the valve seat, an actuating lever being fastened at the side of the diaphragm remote of the valve seat, the free end of the actuating lever communicating with a tappet which is movable transversely relative to the longitudinal axis of the actuating lever and is coupled with the fuel tank lock. The valve seat is enclosed by an annular space which can be completely covered by the diaphragm, wherein the annular space communicates with a branch of the gas line and the interior space of the valve seat communicates with the other branch of the gas line.

Abstract: A self-closing fuel tank closing device mountable on a fuel tank filler pipe includes a filler cap which is tensioned in the direction of a sealing seat and is rotatable in the direction of the interior of the filler pipe. The filler cap is carried by a swivel arm supported at one end thereof. In order to achieve a small construction and degressive torque characteristics on opening the filler cap, it is provided that the free end of the swivel arm is supported on a supporting surface which runs approximately perpendicular to the longitudinal axis of the fuel tank closing device. The device further includes a clamping device which pretensions the filler cap in the direction of the sealing seat and is mounted on the swivel arm in the region between the free end and the filler cap.