GB435663A - Improvements in electric lamps and similar devices - Google Patents

Abstract

435,663. Leading - in wires and filament supports for electric lamps &c. BRITISH THOMSON-HOUSTON CO., Ltd., Crown House, Aldwych, London. Dec. 7, 1934, No. 35214. Convention date, Dec. 8, 1933. [Class 39 (ii)] In manufacturing electric lamps, thermionic valves and similar devices, terminal members 10, 11, Fig. 1, are united to the edges of preformed openings in a glass body 13, after which the. ends of rigid leads 22, 23, Fig. 3, supporting a filament or other energy translation element are secured to the terminals 10, 11, the open edge of the glass body being subsequently sealed to the neck of a bulb. The body 13 is preferably of pressed glass, with outwardly extending tubular portions 16, 18 to the edges of which the thimbles or terminal members 10, 11 are fused, the thimbles preferably being made of copper with a tapered edge or rim 15 around which a ring 14 of glass is sealed to facilitate the joining process. Joining is effected by heating the projection 16 and edge of thimble 10 by a series of rotating fires, bringing these parts together and then pulling them apart to stretch and shape the seal. The thimble 11 and an exhausting-tube 12 are attached similarly. The leads 22, 23 are substantially of U-shaped section, with tubular ends 24 which engage within the smaller ends 25 of the thimbles, where they are secured by making annular indentations 26 in both members. The translation element or filament 27, Fig. 5, is mounted on the leads by means of insulating blocks 28, 29 of material such as asbestos, which are secured to the leads 22, 23 by bent wires 30, and carry filament-supporting wires 31, 32. The filament 27 is preferably coiled, with uncoiled ends 33 which are covered by separate tightly coiled sections of wire and welded to the respective leads 22, 23. Specification 377,602 is referred to.