GB407565A - Improvements in luminous electric discharge lamps - Google Patents

Abstract

407,565. Discharge lamps. GENERAL ELECTRIC CO., Ltd., Magnet House, Kingsway, London.-(Assignees of Patent-Treuhand- Ges. fur Elektrische Gl³hlampen ; 11, Ehrenbergstrasse, Berlin.) May 22, 1933, No. 14759. Convention date, May 23, 1932. [Class 39 (i).] In a lamp adapted to emit light from a tortuous discharge path in a direction normal to the plane containing at least two limbs of the path, the form of the discharge path is determined by a metal structure which is enclosed in a vitreous envelope which does not determine the form of the said path. The structure consists of a tungsten, nickel or iron box provided with partitions 11, 12, 13, which are formed of solid metal or of wire gauze. One or both of the sides 14, 15 of the structure are formed of glass, quartz or of wire gauze. Thermionic electrodes 18, 19, heated by the discharge, are housed in tubular extensions 16, 17. Termination of the discharge at the metal structure is prevented if the potential drop of the positive column is less than the sum of the falls of potential of the anode and cathode, or if the structure is oxidized. The structure may be silvered to form a reflector and may be connected through a resistance to one electrode to facilitate starting. Parts of the structure may be separated by insulation to form starting electrodes. The invention may be applied to a lamp which is formed so as to lie on a curved surface in such manner that any two straight portions of the discharge are parallel to each other and to the axis of the said surface.