Dielectric stress relief at a high voltage cable termination

Claim 1

Means for relieving dielectric stress at a termination of a shielded and insulated high voltage cable including a housing that defines an opening for receiving a said high voltage cable, which housing comprises a layer of insulative material having a generally cylindrical shape, a conductive high voltage electrode at the inner surface of the housing for making contact with the conductor of a said high voltage cable, and a conductive ground electrode at the outer surface of the housing for conductive coupling to the shielding of a said high voltage cable, said ground electrode defining the mouth of the opening in the housing and diverging from the opening; and a tube of homogeneous insulative material having a relatively smooth geometry, being adapted for surrounding an exposed portion of the insulation of a said high voltage cable, and being adapted for positioning in the opening of the housing while surrounding said exposed portion with one end of the tube coaxially contacting the ground electrode at the mouth of the opening and the other end of the tube coaxially contacting the high voltage electrode; said housing characterized by the mouth of the opening being substantially the same diameter as the remainder of the opening; and said tube characterized by consisting of a nonrigid elastomeric material having a permittivity in a range from 10 to 25, characterized by having an outward extending ridge on one end that exceeds the diameter of the mouth of the opening to limit the relative insertion of the tube into the opening, and a conductive nonrigid elastomeric tubular extension integral with the other end of the tube for forming a part of said high voltage electrode, said conductive extension having a lip extending inwardly for contacting an exposed portion of the high voltage conductor of a said high voltage cable and at least a portion of the insulation adjacent said exposed portion of the high voltage conductor of a said high voltage cable.