GB716406A - Improvements in and relating to filament lamps - Google Patents

Abstract

716,406. Electric incandescent lamps. BRITISH THOMSON-HOUSTON CO., Ltd. Sept. 14, 1953 [Oct. 20, 1952], No. 26253/52. Class 39 (2) In an electric incandescent lamp comprising a metal collar 1 adapted to be sealed to a reflector, a base portion 2 located within and hermetically sealed to the collar, and filament-supporting leading in wires insulatingly sealed through the base portion and extending outwardly of the lamp, the inner surface of the base portion is treated so as to provide a reflecting surface. In the example a metal base portion 2 located within and either integral with or sealed to a metal collar 1 is of parabolic form and supports four leading-in wires 3-6 which are sealed therein by individual glass globules 7-10 respectively. Two filaments 11 and 12 mounted on the respective pairs of leading-in wires are so positioned relative to the collar 1 that they are positioned in a predetermined manner relative to a reflector sealed subsequently to the collar. The filament-supporting leads may be made of nickel, or an alloy of nickel and iron, or nickel-plated copper or iron, and their outer ends 13 may be connected finally to contact pins on a base or may themselves serve as contact pins. The concave parabolic surface 14 may be rendered reflecting by any known " silvering " process or, if made of metal may be highly polished. The open neck 15 of a glass bulb or envelope may be sealed to the collar 1 either directly or by a suitable solder glass. In a modification, Fig. 2 (not shown), the metal collar 1 is of inverted dished form. Specification 698,465 is referred to.