GB353905A - Improvements relating to electron discharge tubes or thermionic valves - Google Patents

Abstract

353,905. Thermionic valves. NAAMLOOZE VENNOOTSCHAP PHILIPS' GLOEILAMPENFABRIEKEN, 13A, Emmasingel, Eindhoven, Holland. April 29, 1930, No. 13191. Convention date, Sept. 25, 1929. [Class 39 (i).] Filamentary cathodes consists of more than two filament spans electrically connected together at least at one end by a conductor 7, Fig. 1, the spans being tensioned each by a spring 8 interposed between the span and the conductor 7 so that the spans can expand independently. The cathode may be in sections connected together by the conductor 7 and mounted directly on the pinch, each section comprising spans connected in parallel. In Fig. 1, two sections each consisting of four spans are shown, the conductor 7 connecting the spans in parallel and also connecting the two sections in series. The conductor 7 may support the springs 8 and may be carried by glass beads 6 receiving grid and anode supports 4, 3. The ends of the springs 8 may be turned round the conductor 7 and secured by a strip 13, Fig. 3, welded to the conductor 7 and to the springs. The lower ends of the spans may be similarly supported. on springs. In a modification, Fig. 5, the springs are supported by, and have a sharply doubled part embedded in, a glass rod 14 and are welded to the conductor 7 at a distance from the rod 14. Specification 271, 945, [Class 39 (i), Electric lamps, Arc &c., is referred to.