Vacuum interrupter with single insulating member having conical exterior attaching surfaces and supporting a floating shield

Claim 1

In a vacuum interrupter, a hollow insulating member, said insulating member having first and second spaced-apart conic exterior surfaces and having an external and an internal flange, an electrically conductive envelope having first and second openings therein, the portion of said envelope surrounding said first opening having a conic surface adapted to mate with said second conic surface of said insulating member to provide an expandable sealed joint, a stationary contact member extending through said insulating member into said envelope, the relative sizes of said insulating member and said stationary contact member being such as to provide internal clearance space therebetween which is substantially smaller than the diameter of said stationary contact member, said internal flange on said insulating member further reducing said clearance space to allow only for thermal expansion clearance in the region where said stationary contact emerges from said insulting member into said envelope, sealing means connected between said stationary contact member and said insulting member to support said stationary contact member and to seal off said internal clearance space, said sealing means having a conic surface adapted to mate with said first conic surface of said insulating member to provide an expandable sealed joint, a movable contact member extending through said second opening in said envelope, flexible electrically conductive sealing means connected between said movable contact member and said envelope and located exteriorly of said envelope, and an electrically conductive floating shield surrounding portions of said stationary and movable contact members, said shield being supported by said external flange on said insulating member.