GB513715A - Improvements in electric discharge lamps - Google Patents

Abstract

513,715. Discharge lamps. GENERAL ELECTRIC CO., Ltd. (Patent-Treuhand-Ges. fur Electrische Gluhlampen). May 12, 1938, No. 14190. [Class 39 (i)] In an electric discharge lamp wherein partitions subdividing the envelope fit it so closely that the discharge cannot pass round their edges and so force the discharge to take a path much longer than the straight line joining the electrodes, the partitions are made wholly or partly of metal coated with an insulating material. In one form, Fig. 1, the discharge is made to pass to and fro along the cylindrical envelope 1 by longitudinal radial partitions 2 carried on a coaxial tube 4. The sectors are closed at each end by discs 7 and the partitions are pierced by holes 12 alternately at the top and bottom to allow the discharge to pass from one sector to the next. The discharge from the electrode 6 enters a space within the partition structure through a hole 8 in the end disc 7. Within the tube 4, a stabilizing impedance 5 is connected between electrode 6 and its external lead. In another form, Fig. 3, the cylindrical envelope 1 is subdivided by two interlacing helices carried on the coaxial tube 4, so that the discharge follows the path between electrodes 13 and 14 indicated by the arrows. The partitions are preferably highly reflecting and may be of iron coated with a suspension of zirconia sintered on, or they may be of aluminium electrolytically oxidized. They may act as auxiliary electrodes and they and the electrodes may be made apart from the envelope and then slipped into it. The insulating coating may be of luminescent material and the envelope may be similarly coated. Specification 407,563, [Group XVIII], is referred to.