Electrical heating element and fitting assembly

Claim 1

An improved heating element and fitting assembly for mounting within spaced openings in a wall of a liquid heating vessel, said assembly comprising an elongated tubular sheath having opposite end portions, an electrical resistance heating element extending longitudinally within said sheath and supported therein by a thermally conductive insulator material, an electrical connector connected to each end of said heating element and projecting through the corresponding said end portion of said sheath, a drawn sheet metal tubular fitting mounted on each said end portion of said sheath and adapted to extend through the corresponding opening within the wall, each said fitting including an outwardly projecting peripheral flange portion integrally connected to a tubular wall portion, said tubular wall portion of each said fitting having a corrugated wall configuration of substantially uniform wall thickness and forming helical threads having an inner diameter substantially the same as the outer diameter of said sheath, means for rigidly securing each said fitting to the corresponding said end portion of said sheath and forming a liquid-tight seal between said fitting and said sheath, and a nut member mounted on said tubular wall portion of each said fitting and having helical threads conforming to said threads on said fitting for liquid-tight securing said fitting to the wall.