Patent ID: 7090192

Claim:
A vacuum valve comprising: a valve body with a valve opening; a valve plate which is movable between an open position in which it lies next to the valve opening and releases the valve opening and a closed position in which the valve opening is covered; and a diaphragm plate which is movable between a passive position, in which it lies next to the valve opening and releases the valve opening, and an active position in which it partially covers the valve opening; wherein the vacuum valve has a completely open state in which the valve plate is in its open position and the diaphragm plate is in its passive position, a completely closed state in which the valve plate is in its closed position and the diaphragm plate is in its active position and the valve plate is sealed relative to the valve body, and a partially closed state in which the valve plate is in its open position and the diaphragm plate is in its active position, wherein the vacuum valve has a reduced cross section compared to the completely open state.