GB489626A - Improvements in the sealing of electric conductors through quartz envelopes - Google Patents

Abstract

489,626. Sealing leading -in wires; discharge lamps. GENERAL ELECTRIC CO., Ltd., FRANCIS, V. J., HARRIS, N. L., RYDE, J. W., and SCHNETZLER, K. G. Jan. 28, 1937, No. 32934. Divided out of 489,630. [Class 36] [Also in Group XL] A plurality of metal strips are arranged within a flattened tube of quartz or like material, the strips being substantially parallel to the axis of the tube and being spaced apart in a plane parallel to the longest dimension of the cross-section of the tube, the tube is heated so that its flattened sides collapse on to the strips in a direction substantially perpenclicular to said plane, and the body so formed is joined to the sides of an aperture in an envelope of quartz or like material. Molybdenum strips 6, Fig. 3a, are welded to molybdenum wires 7, 8, the wires 7 being twisted at 9 and the wires 8 held together temporarily by a cross wire 10. The strips are then placed in a quartz tube having circular parts 11, 12 and a flattened part 13 : the parts 12, 13 are then heated so that they collapse on the cable 9 and strips 6 respectively, and the ends of the parts 11, 12 are cut off. Electrode systems comprising running electrodes 2 and starting electrodes 4, Fig. 4, are then welded to the cables 9 of two strip systems and the parts 14 inserted in tubes 15 of the envelope 1 of a high pressure mercury vapour discharge lamp, a pumping tube 16 being attached to the envelope. Inert gas is passed into the envelope, the tubes 15 collapsed on to the parts 14, and the envelope is eventually sealed off at 17. The electrodes 4 may comprise rods of alkaline earth enclosed in tungsten spirals. British Specification 476,488 and U.S.A. Specification 1,271,245 are referred to. The Provisional Specification refers also to Specification 396,103, [Group XI].