Electrical insulating bushing with a weather-resistant sheath

Claim 1

A rigid insulating bushing arrangement which passes through, and is stationarily supported by, a casing wall of a high voltage electrical apparatus exposed to weather, said bushing arrangment comprising: (a) an elongated, rigid electrical conductor extending in an axial direction through a casing wall of a high voltage electrical apparatus; (b) a rigid tubular insulating member of synthetic resin cast around so as to be bonded in a gas tight manner to the electrical conductor and having an interior portion adapted to be located within the casing wall of the apparatus, and an elongated exterior portion unitary with, and extending axially from, the interior portion beyond the casing wall of the apparatus, said exterior portion having an end face; (c) a flange around the rigid tubular insulating member in engagement with the casing wall and serving to support the tubular insulating member from the casing wall; (d) a sheath of weather-resistant insulating material mounted on and enclosing the exterior portion over a major portion of the length of the exterior portion, said sheath including a plurality of axially overlapping and interfitted, individually distinct collars which together extend over the major portion of the length of the exterior portion, said collars being readily detachable from the exterior portion, said sheath further including an insulating cap covering the end face of the exterior portion and detachably mounted on the one of the collars nearest the end face; and (e) a stress cone around the rigid tubular insulating member and axially overlapping and interfitted with the one of the collars nearest the interior portion of the tubular insulating member.