VACUUM INTERRUPTER

A vacuum interrupter includes a vacuum envelope having a cylindrical metallic housing with at least one opening end and a disc-shaped and apertured end plate of insulating ceramics which is hermetically sealed to the opening end. One metallized layer to which the opening end is hermetically brazed is in an outer-diameter region of a sealing surface of the plate, while another metallized layer to which another metallic members of the envelope is hermetically brazed is formed in an inner-diameter region of the plate. There are provided, within the envelope near two spaced edges of the inner-diameter region and outer-diameter region metallized layers, metallized-layer-edge shields having opposite surfaces separated by a distance which is smaller than that between the metallized layers. Each of the opposite surfaces has extensions at the axial opposite ends so that each extension extends away from an extension of the other surface. The shields increase significantly the internal dielectric strength of the envelope.