Sheathed electric heating element assembly

In a metallic sheathed electric heating element assembly having a resistance element, a sheath surrounding said resistance element, pulverulent electrically insulating material within said sheath and surrounding said resistance element, said insulating material being tightly compacted and extending within said sheath short of an open end thereof, and a terminal pin electrically and mechanically connected to an end of said resistance element within the compass of said sheath, said resistance element contiguous its place of attachment to said pin being surrounded by said compacted insulating material, the improvement comprising said pin having an inner part to which said resistance element is connected, and an outer part spaced from said inner part, and a thermal switch electrically connected to and in series between said inner and outer parts, within said sheath but spaced toward said open end from said compacted insulating material, bushings adjacent ends of said thermal switch, said bushings being of a diameter greater than that of the thermal switch, and a sleeve surrounding said bushings and said thermal switch.