GB381420A - Improvements in or relating to electric incandescent lamps or discharge tubes - Google Patents

Abstract

381,420. Thermionic valves. DICKER, S. G. S., 20, Holborn, London.-(Naamlooze Vennootschap Philips' Gloeilampenfabrieken ; 13D, Emmasingel. Eindhoven, Holland.) Jan. 7, 1932, No. 497. [Class 39 (i).] The bulbs and screw caps of electric discharge tubes are connected in such a manner that a limited free movement is provided between them without the interposition of an elastic body or elastic connection. In one form an inner cap 2, Fig. 1, cemented to the bulb 1 is provided with three lips or projections 3 adapted to be inserted within apertures 5, Fig. 2, in the screw cap 4 and bent over at their ends to ensure a limited free movement of the screw cap in the axial direction relatively to the bulb, the sizes of the lips and slits preferably being such that no appreciable movement in a tangential direction is admitted. The leading-in wires 7, 8 are connected respectively to the centre contact of the cap 4 and the inner cap 2. In another form an inner cap 10, Fig. 5, cemented to the bulb is provided with three radial pins 11 adapted to be engaged within corresponding apertures 13 in the screw cap 12, the apertures being of sufficient size to allow a limited movement of the pins 11 within them. An inner,cap may be dispensed with by providing the bulb itself with projecting parts or re-entrant portions co-operating with corresponding apertures, cavities, or projecting parts of the cap. Specification 381,637 is referred to.