Cartridge heater structure

A cartridge heater structure comprising an elongate cylindrical metal case with front and rear ends, an elongate heater element supported within the case, a plug of dielectric material within at least the rear portion of the case axially forward of the rear end of the case, elongate flexible jacketed power lines with front end portions extending through the plug and electrically connected with said element and rear end portions extending rearwardly from the case, an elongate tubular flexible braided metal sheath with front and rear ends engaged about and extending longitudinally of the lines and a coupling structure coupling the front end of the sheath with the rear end of the case, said coupling structure including an elongate axially extending inner tube part freely engaged about the lines and within the front portion of the sheath, an elongate axially extending outer tube part engaged about the inner tube part with a forward portion of the sheath held securely therebetween, one tube part has a radially outwardly projecting flange arranged within the rear portion of the case between the rear end of the case and the plug and retaining means between the rear end portion of the case and said flange retaining the flange in the case and against axial rearward displacement therefrom.