Polyester bushing and method of making same
AssigneeGeneral Electric Company
InventorsPhilip A. Cacalloro, Joseph A. St. Jacques
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Abstract
An improved electrical bushing is disclosed which includes, in combination, an insulating body of a polyester material, a current-carrying stud, and an adhesive coating applied to the grooved peripheral surface of the stud. The bushing is manufactured by applying the adhesive coating to the peripheral surface of the stud. The polyester insulating body is then molded about the stud. Heast is applied to concurrently cure the polyester body and adhesive coating to achieve a bonded, fluid-tight seal between the stud and the insulating body.
Claims18
An electrical bushing for connection at one end to a power line and at its other end to electrical apparatus including a housing through which the bushing is adapted insulatively to carry electric current between the power line and the electrical apparatus, the bushing including, in combination,
- (a) a massive insulating body of a polyester material.
- (b) a current-carrying metal stud, and
- (c) a film-like adhesive coating of an epoxy-based adhesive far thinner than the wall thickness of said body applied to the peripheral surface of said stud and adhesively bonded to the metal stud, said polyester-material body being molded about said coated stud in bonded, fluid-sealing relation with said coating and said stud by (i) a molding operation that brings said polyester material in uncured condition and under substantial pressure into contact with said adhesive coating about the outer surface of said adhesive coating after said adhesive coating has dried but not fully cured and (ii) a curing operation that effects curing of said coating and said polyester material while in contact.
A method of manufacturing an electrical bushing having, in combination, a massive insulating body surrounding a current-carrying metal stud, said method comprising the steps of:
- (a) applying a film-like adhesive coating of epoxy-based adhesive far thinner than the wall thickness of said body to the peripheral surface of said stud;
- (b) molding said insulating body of a polyester material about the adhesive-coated peripheral surface of said stud by a molding operation that brings said polyester material in uncured condition and under substantial pressure into contact with said adhesive coating about the outer surface of said adhesive coating after said adhesive coating has dried but not fully cured;
- and
- (c) heating said stud and said insulating body to cure said polyester material and said adhesive coating while in contact, thereby effecting an adhesive bond between said stud and said cured coating and also a bonded, fluid-tight seal between said body and said stud through said adhesive coating.
Dependencies are inferred from the claim text.