Abstract: A tank bleeder valve for the metered admixture of volatilized fuel to the fuel-air mixture of an internal combustion engine has a valve housing with inflow and outflow necks, between which an electromagnetically actuatable seat valve is disposed. The inflow neck communicates with the vent neck of a fuel tank, and the outflow neck communicates with the engine intake manifold. To prevent dieseling of the engine after the ignition is switched off, the seat valve is embodied such that it is very tightly closed when there is no current. To this end, the valve opening of the seat valve is embodied as an annular gap, coaxially surrounded on the inside and outside by a valve seat in the form of an annular double seat. The valve element of the seat valve is embodied as an annular disk of magnetically conductive material, which is loaded with a closing force acting in the closing direction of the seat valve. The annular disk simultaneously acts as the armature of the electromagnet.

Abstract: A rotary positive-displacement pump in which the vane or vanes separating the chambers are locked in the inner dead center point after a certain outlet pressure has been attained, in order to shut off the pump. A corresponding locking apparatus has a detent which assures that each vane is locked in a form-locking manner in the position which shuts off the pumping action. Preferably, the locking apparatus has an overstroke step by means of which it is assured that each vane is constantly held at an increased distance from its sliding surface so that friction and impact noises are positively avoided.