GB512791A - Improvements in or relating to gas-filled incandescent electric lamps - Google Patents

Abstract

512,791. Electric incandescent lamps. SOC. ANON. POUR LES APPLICATIONS DE L'ELECTRICITE ET DES GAZ RARES ETABLISSEMENTS CLAUDE-PAZ & SILVA. March 15, 1938, No, 8018. Convention date, Jan. 27. [Class 39 (ii)] The bulb of a gasfilled lamp terminates at its two opposite ends, E', E<2> in pinches T', T<2> respectively, located on the outer surface of the container and supporting filaments F<1>, F<2> connected in series by a conductor X situated outside the bulb or container, which encloses, no part made of glass. The bulb is made of small volume in relation to its power and may be filled with a mixture of 98 per cent. xenon and 2 per cent. nitrogen. To avoid overheating, the bulb and both pinches are preferably made of a glass which is transparent to infra- 'red rays. In the example the lamp bulb is enclosed within an outer bulb Z and is maintained in position by a doubly bent rod Y at its upper end. The outer bulb may be made of frosted, opal, or enamelled or coloured glass, and the space between the bulbs may be filled with a cooling- fluid. When the inner bulb has a filling containing more than 50 per cent. of xenon, its internal volume in cubic' centimetres may be less than that given by the formula V=4 #W where W is the rated wattage of the lamp. To avoid excessive volatilisation of the tungsten filaments however, the volume is preferably greater than #W