Terminal bushing for electrical apparatus comprising a polymeric shell molded about a central conductor

摘要

A terminal bushing which has (a) an elongated central conductor made by a powder metallurgy process from metal particles sintered together at elevated temperatures after being compacted under pressure and (b) a tubular shell of polymeric insulating material molded under high within a mold pressure about the central conductor and forming a joint with the central conductor that has a high resistance to leakage along the conductor. The central conductor includes at opposite ends of the molded tubular insulating shell mold-interface regions that are formed by the powder metallurgy process and are located to interface with and to fit tightly within the mold that is used for molding the insulating shell, thereby limiting to low values the quantity of pressurized polymer ejected about the mold-interface regions during the molding.