GB473162A - Electric overload cut-out - Google Patents

Abstract

473,162. Cut - outs. VEREINIGTE GLUHLAMPEN UND ELEKTRIZITATS AKT.-GES. July 23, 1936, No. 20414. Convention date, July 23, 1935. [Classes 37 and 38 (i)] [Also in Group XI] In an electric cut-out having a metallic core surrounded by a protecting metal sheathing, wherein upon passage of excess current the core is oxidized and is thereby rendered a high resistance, the metallic core and the sheathing are each formed of a metal alloyed with another metal, the latter metals being intermediate the core metal and the sheathing metal in the electromotive series and exhibiting among themselves a small potential difference only in this series. The effect is to reduce corrosion. A common constituent of the core and sheath alloys may be used, being preferably a metal of the iron group. In an example, a molybdenumnickel alloy is used for the core and a nickelsilver alloy for the sheath. The cut-out may be provided in the cap of a gas-filled incandescent lamp preferably of the type having spiralized filaments and the quantities of the metals alloyed with the core and sheath metals are chosen so as not to permit the evolution of metallic vapour in sufficient quantity to afford a conducting path for the current to which the cut-out responds. Specification 442,172 is referred to.