GB418867A - Improvements in or relating to electron discharge tubes or electric incandescent lamps - Google Patents

Abstract

418,867. Thermionic valves. NAAMLOOZE VENNOOTSCHAP PHILIPS' GLOEILAMPENFABRIEKEN, 13D, Emmasingel, Eindhoven, Holland. Oct. 26, 1933, No. 29765. Convention date, Feb. 4. [Class 39 (i).] Electron discharge tubes or electric incandescent lamps are provided with a cap or plate of vacuum-tight ceramic material, other than a ceramically shaped and densely burned mass of magnesium silicate, which forms part of the wall of the tube or lamp and in which the supporting and leading-in wires for the electrodes or filament are mounted, the usual stem being dispensed with. The porcelain known under the Registered Trade Mark " Calit " may be used as the vacuum - tight ceramic material. In the example, contact pins 2 with their ends inserted within the ceramic cap 1 are connected to the leading-in conductors 3, which may serve also as electrode-supportingwires. The cap is provided with strengthening ribs or shoulders 4 which may be disposed at right-angles to each other. Alternatively, the ribs may be of other shapes, for example, circular, as shown dotted in Fig. 2. The upper edge of the cap may be provided with a groove 8 which may receive a layer of molten glass into which the glass bulb 7 is sealed. Instead of making the cap entirely of the ceramic material a plate-shaped ceramic portion may be mechanically united with a layer of other material carrying the external contact members. The bulb may be made of the same ceramic material as the cap.