GB172615A - Improvements in and connected with electric incandescent lamps - Google Patents

Abstract

172,615. Skaupy, F. Nov. 16, 1921. Filaments; lamps with filaments non-conductive when cold.-The incandescing body 1 comprises a transparent refractory and preferably coloured substance free from cloudiness and from the Tyndall effect, and therefore adapted to emit selective radiation determined mainly by the chemical composition of the body, and but slightly by its temperature. It may be arranged in heat-conducting connection with a metallic conductor 2 of very small radiating surface. The body may be coloured by substances incorporated in it or applied to its surface. It may consist of oxides, nitrides, carbides, sulphides, and fluorides of thorium, scandium, magnesium, boron, &c. sintered to produce the transparent condition, and may take the shape of discs, balls, pictorial illustrations, signs, &c. It may be produced similarly to artificial gems, heat being applied to the material externally or by passing an electric current of very high frequency through a mixture of the material and a substance which renders it conducting and evaporates away. The colouring material may consist of oxides, nitrides, &c. of cerium, titanium, zirconium, &c., or the metals themselves applied to the surface of the body, and more than one colour may be applied to each body. The conductor 2 may be applied to the bodv in colloidal solution and sintered, or as easily reducible compounds, for example colloidal tungstates, afterwards heated in a reducing atmosphere, or they may be applied by cathodic atomization. They may be in the form of a spiral or be in several axial lines parallel to the body 1, either on the exterior surface or, in the case of hollow bodies, in the interior thereof. Specification 1580/82 is referred to.