An electrical transformer housing or the like, adapted for direct-buried installation, comprises a tank and a cover sealed thereto, formed of composite walls. The walls have a formed metal liner over substantially their entire area and a molded plastic outer layer covering the entire outer surface of the liner, molded in place against the liner and bonded thereto. Rims on the tank and cover are molded integrally with the plastic outer cover, are sealed to each other outward of the liner by an intervening gasket, and interfit in a trough which receives sealing compound to fix the rims together and provide a secondary seal. Terminal conductor inserts are molded in place in bushings molded integrally with the outer layer of the cover, through openings in the cover liner. The metal liner forms a vapor barrier over as much as 99 percent of the area of the tank and cover to exclude moisture or other fluid which diffuses through the plastic outer layer and the plastic exterior protects the liner and provides corrosion resistance and other advantageous properties.

Sealed power transformer

Composite electrical transformer housing

An integrally bonded composite structure of a substrate part or layer of metal or the like, an elastic interface layer, and a thermoset plastic wall or layer molded in place against it is formed by: (1) coating the substrate, as by spraying, with a thin coating of a thermosetting soluble elastomer, such as a chloroprene rubber (Neoprene), formulated to chemically bond to the substrate surface, and also containing a coupling agent which will react with the thermoset plastic layer during curing of the latter; (2) heating the coating to dry and stabilize the same on the substrate so as to withstand transfer flow of molding composition but without completely curing the coating composition; and (3) molding the plastic layer against the coated substrate under heat and pressure as in a heated molding die while the coating is in incompletely cured state, and thereby completing the curing of the coating as the molded plastic layer is cured and producing an integral chemical bond from the molded layer through the interface layer to the substrate. This gives an impervious seal between the substrate and the plastic and a bond with very high resistance to separation. The parts and the interface between them may be of either simple or complex shape.

Composite of metal and thermoset plastic

An hermetic sealing system for plastic tanks and covers. A plastic tank has a flat surface on the upper edge of its wall, such surface having a first groove formed therein. A lip portion extends from the flat surface and has a second groove therein. A flexible gasket is mounted in the first groove extending above the flat surface. A cover member rests on the flat surface compressing the flexible gasket and has an extending edge portion which fits into the second groove. An epoxy material is poured into the second groove and cured thus sealing the cover to the tank.

Hermetic sealing system for plastic tank and cover

An electrical transformer having a core-winding assembly, with the core-winding assembly and all other metallic parts of the transformer totally enclosed within a nonmetallic casing. The core-winding assembly is supported in the nonmetallic casing from the top cover of the casing. The nonmetallic casing comprises a nonmetallic bottom which is keyed into the sidewalls of the nonmetallic casing to provide a fluidtight joint.

Transformer having a nonmetallic casing

A distribution transformer assembly for an electrical power distribution system, the transformer assembly including a fluid-tight non-metallic enclosure which can be buried in the ground, a distribution transformer having a primary and a secondary winding positioned within said enclosure, said enclosure including sealed primary and secondary electrical terminators or bushings for operatively connecting the transformer to the distribution system and insulating liquid substantially filling said enclosure to dissipate heat losses through the walls of the enclosure to the adjacent ground, at least one of the terminators having a one-way vent to the atmosphere.

An under-ground vented non-metallic transformer assembly

This invention relates to high frequency transformers of types capable of use for substantial amounts of power. The objects of the invention include the provision of highly dependable transformers of the above indicated type, in which the working temperatures and power losses will be low,...

Sealed power transformer

Citations

Composite electrical transformer housing

Composite of metal and thermoset plastic

Hermetic sealing system for plastic tank and cover

Transformer having a nonmetallic casing

An under-ground vented non-metallic transformer assembly

References

High-frequency power transformer

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