GB733879A - Improvements in or relating to electric lamps - Google Patents

Abstract

733,879. Electric incandescent lamps. PHILIPS ELECTRICAL INDUSTRIES, Ltd. Jan. 30, 1953 [Feb. 4, 1952], No. 2753/53. Class 39 (2). [Also in Group XXI] The leading-in wires to the filament of an electric incandescent lamp or photographic flash lamp are brought to the exterior of a cylindrical non-conductive lamp cap to serve as terminal contacts, the end portion of one of the wires being secured to the cap surface near the bulb wall and the end portion of the other wire secured at a part of the cylindrical surface remote from the bulb wall. The leading-wires 4, 41 may be taken through separate channels 5, 5<SP>1</SP> in a cap 2, preferably made of synthetic resin, and the end portions of the wires brought out through apertures at different distances from the lamp bulb and carried around the surface of the cap, the extremities of the wires being fixed by spots of adhesive 7, 71 respectively in cavities provided in the cap surface. Holders for use with the lamps are provided with contacts in positions corresponding to those of the ends of the leading-in wires. In order to facilitate the fixing of the lamp in a holder the part of the cap that carries the leading-in wire remote from the bulb may be made of smaller diameter than the other part and may also be slightly conical. Fig. 3 shows a modification comprising a cap of thermoplastic synthetic resin with two cylindrical portions of different diameters provided respectively with vertical positioning-ribs 10, 10<SP>1</SP> and 11, 11<SP>1</SP>, the interior of the cap being hollow so that the leading-in wires, 4, 41 can be located therein parallel with the axis and their end portions 8, 8<SP>1</SP> brought out and then bent upwardly over the two cylindrical surface portions and secured within grooves 9, 91 by applying a hot iron at those points. In further modifications, Figs. 5 and 6 (not shown), the portion of the cap of reduced diameter has a deep radial slot through which one leading-in wire is brought and then bent upwardly and secured on the wider portion of the cap. The caps may be secured to the bulbs by adhesives such as water glass or those having synthetic resin as basis. In the case of flashlight bulbs coated externally with a layer of lacquer the applied lacquer solution may cover part of the cap and, on hardening, secure the cap to the bulb.