GB489630A - Improvements in the sealing of electric conductors through quartz envelopes - Google Patents

Abstract

489,630. Stealing leading-in conductors ; discharge lamps. GENERAL ELECTRIC CO., Ltd., FRANCIS, V. J., HARRIS, N. L., RYDE, J. W., and SCHNETZLER, K. G. Jan. 28, 1937, Nos. 2538 and 13553. [Class 36] [Also in Group XL]. A plurality of thin metal strips are arranged side by side in the space between an outer tube of quartz or like vitreous material and an elongated core, which may be a tube or rod, of the same or similar vitreous material extending along the axis of the outer tube, the lengths of the strips being substantially parallel to the axis of the outer tube ; the tube is softened by heat and caused to collapse on the strips and core ; and, a vitreous part of the body so formed is joined to the sides of an aperture in a quartz or like envelope. The tube and core may be circular, flattened or polygonal. Molybdenum strips 3, Fig. 9a, welded to molybdenum wires 4, are sealed between a quartz core 2 and quartz tube 1, the latter being exhausted before being collapsed on to the core ; the uncollapsed portions are cut away at 5 and one of the ends sealed in an aperture in an envelope. In Fig. 10e, two wires 7 are welded to each end of each of two molybdenum strips 6; these bodies and a core 8 are held by a jig 10 in a tube 9 closed at one end : the tube is evacuated, collapsed on to the strips 6 and core 8, a flange 11 added, one end of the tube cut off at 12, an electrode system mounted on the protruding wires 7, the body sealed in an aperture in an envelope 14, Fig. 11, and the other end of the tube 9 finally cut off. Dimensions of the lamp are given. In another form, Fig. 3, a seal comprisirig an outer tube 6, core 7 and strips 13 is used in a high-pressure mercury-vapour discharge lamp having a spherical quartz bulb 1, electrodes 15 comprising perforated tungsten canisters filled with alkaline earths, and a hood 4; in a modification, the seal is interrupted between its ends by an enlargement of the outer tube in which stouter molybdenum wires are employed to join strips on either side. Fig. 5 shows an incandescent lamp in which the filament 20 is carried by wires 18, 19 connected to strips 8 within the seal and by a wire 21 fixed in the inner face of the seal. In a further form, Fig. 7, an inner tube 18 sealed to the core 7 by intermediate glasses, carries a lead-in conductor 17 independent of the strips 8. In yet another form, Fig. 8, a wire 26 acting as support for the filament 27 connected across the electrodes 2, 3 of a discharge lamp, protrudes from a rod 25 forming the core of the seal. British Specifications 472,658, [Group XL], 476,488, and 476,833, and U.S.A. Specification 1,271,245 ate referred to. Specification 396,103, [Group XI], also is referred to in the first Provisional Specification.