Electrical heating element and fitting assembly

Claim 2

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 member extending longitudinally within said sheath, a thermally conductive electrical insulation material supporting said resistance heating member within said sheath and extending through each said end portion to a substantially flush relation with the end surface of said sheath, an electrical terminal connector extending from each end of said resistance heating member through the corresponding said end portion of said sheath, a sheet metal tubular fitting mounted on each said end portion of said sheath, each said fitting including an outwardly projecting peripheral flange portion integrally connected to a tubular wall portion projecting beyond the corresponding said flush end surfaces of said sheath and insulation material, said tubular wall portion of each said fitting having helical convolutions of substantially uniform wall thickness and forming external helical threads, and a sealant material surrounding each said end portion of said sheath and extending into the space defined between the corresponding end surface of said tubular wall portion and said flush end surfaces of said sheath and insulation material.

Claim 3

A heating element and fitting assembly as defined in claim 1 wherein each said fitting includes an annular hub portion having a curved inNer surface firmly engaging the corresponding said end portion of said sheath and providing a lead surface to facilitate mounting said fitting on the corresponding said end portion of said sheath.

Claim 4

A heating element and fitting assembly as defined in claim 2 wherein said flange portion includes a first wall portion projecting outwardly from said tubular wall portion, a second wall portion projecting inwardly from the outer periphery of said first wall portion, and said annular hub portion curves axially inwardly from said second wall portion.

Claim 5

A heating element and fitting assembly as defined in claim 1 wherein said convolutions within said tubular wall portion of said fitting have an inner diameter substantially the same as the outer diameter of said end portion of said sheath, and said sealant material extends into the space defined between said convolutions and the outer surface of said end portion of said sheath.

Claim 6

A heating element and fitting assembly as defined in claim 1 wherein said sealant material comprises a heat activated thermosetting sealant.

Claim 7

A heating element and fitting assembly as defined in claim 1 wherein said tubular wall portion includes a cylindrical portion connecting said flange portion to said helical convolutions.

Claim 8

A heating element and fitting assembly as defined in claim 1 wherein said fitting includes an annular hub portion connecting said convolutions to said flange portion, and said hub portion has a curved inner surface firmly engaging the outer surface of said sheath.

Claim 9

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 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 convoluted wall configuration of substantially uniform wall thickness and forming helical threads surrounding said sheath, each said fitting including a portion in radial press-fit engagement with the corresponding said end portion of said sheath, means for rigidly securing said fitting to 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 securing said fitting to the wall.

Claim 10

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 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 convoluted wall configuration of substantially uniform wall thickness and forming helical threads surrounding said sheath, each said fitting including a portion in radial press-fit engagement with the corresponding said end portion of said sheath, means for rigidly securing said fitting to 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 securing said fitting to the wall.

Claim 11

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 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 in axial cross section forming external threads thereon, each said fitting further including an inwardly projecting portion firmly engaging the outer surface of said sheath, and means forming a liquidtight seal beTween each said fitting and the corresponding said end portion of said sheath.

Claim 12

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 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 in axial cross section forming external threads thereon, each said fitting further including an inwardly projecting portion firmly engaging the outer surface of said sheath, and means forming a liquidtight seal beTween each said fitting and the corresponding said end portion of said sheath.