Cable termination housing having means for preventing corona and uniformly grading voltage

Claim 1

An electric power cable termination housing comprising an elongated body of elastomeric insulating material, wall means defining a passageway through said body from one end to another end thereof, and a coating of electrically conductive material mounted on and substantially coextensive with a major part of the outer surface of said body, a portion of said coating of conductive material also being mounted on a predetermined length of said wall means extending inward from said one end of the body, the wall means of said passageway adjacent said one end of the body being resiliently dilatable and adapted to receive therein in watertight sealing relationship an insulated electric cable having a semiconductive outer shield, said resiliently dilatable wall means being operable to hold the conductive coating on the wall means in electrical contact with the semiconductive outer shield on a cable positioned in the housing in watertight sealing relationship with said predetermined length of the wall means, said body of insulating material being formed to define a generally conical outer surface portion near said one end thereof to afford an electrical stress cone for grading electric fields developed when an energized high-voltage cable is mounted in said passageway, and including a generally cylindrical body portion formed integrally with said conical outer surface portion and extending outward therefrom, the outer end of the generally cylindrical portion of said body comprising said one end of the body, said generally cylindrical body portion being formEd to have a substantially uniform wall thickness over a major part of its length and to have a thinner wall thickness for a minor part of its length at the end thereof adjacent said conical outer surface portion of the body of insulating material, said thinner walled minor part of the generally cylindrical body portion being substantially more flexible than the thicker walled major part thereof so that said thicker walled part can move at an angle with respect to the longitudinal axis of said passageway without being stretched sufficiently to break a seal between it and a cable positioned therein while said thinner walled part flexes to allow such movement.