US Patent 7242570 Vacuum capacitor

A vacuum capacitor including an insulating cylinder having first and second ends which are opposite to each other. A stationary-side flange is installed to the first end of the insulating cylinder. A stationary electrode supporting plate is installed to an inner surface side of the stationary-side flange. A movable-side flange is installed to the second end of the insulating cylinder. A movable electrode supporting plate is installed to an inner surface side of the movable-side flange through an electrostatic capacity adjusting screw and movable relative to the stationary electrode supporting plate by turning of the electrostatic capacity adjusting screw. Additionally, a diaphragm is sealingly connected between the movable-side flange and the movable electrode supporting plate, the diaphragm having corrugation and defining a vacuum side and an atmospheric side in the vacuum capacitor.