Composite electrical transformer housing

Claim 1

A housing for an electrical transformer or the like, comprising: a tank having composite side walls of generally tubular configuration and an end wall integral therewith and closing one end thereof, said walls defining a container with one open end, and an integral peripheral rim at said open end arranged for supporting interengagement with a cover rim, and having an upward-facing seal-engaging surface, a cover having a composite dome-shaped end wall for closing the open end of the tank and an integral peripheral rim thereon arranged for interengagement with the tank rim so as to support the cover therefrom and having a downward-facing seal-engaging surface to be sealed to the tank rim, one or more terminal conductors extending through the cover wall, each supported in a bushing therein, said tank and cover comprising a formed metal liner, forming a vapor barrier over the inner surface of the tank or cover of which it forms a part, such liners having edge portions extending at least substantially to the interengaging faces of the rims of such tank or cover and being integral and continuous over the entire inner surfaces of such tank and cover, except for an opening to pass and to provide dielectrical separation from each terminal conductor extending through the housing wall, so that such liners extend at least substantially to the seal between the tank and cover and cover substantially the entire inner surface of the housing walls, the tank and cover also each comprising a corrosion-resistant outer layer of a thermosetting plastic molding composition molded in place under heat and pressure against said formed metal liner and extending over and in continuous bonded relation with the entire outer surface of the liner and extending over and beyond the edges of the liner at the rim of the tank or cover, sealing means between the rims of the tank and cover, including an inner sealing gasket substantially at the edges of the liners, and additional means outward of said liner edge portions to seal and fix the rims together so as to secure the gasket in sealing relation and form a closure outward of the liner edge portions, each said bushing being an integrally-molded bushing of thermoset plastic molding composition molded under heat and pressure about its terminal conductor in integrally-molded and continuous relationship with the adjacent outer plastic layer and in intimate conforming relationship with the terminal conductor so as to fix the same in the housing wall, and means sealing each terminal conductor to its bushing against leakage through the bushing longitudinally of the conductor.