GB371328A - Improvements in and relating to methods of joining metal to glass - Google Patents

Abstract

371,328. Discharge apparatus. BRITISH THOMSON-HOUSTON CO., Ltd., Crown House, Aldwych, London.-(Assignees of Gates, E. F. ; 223, 4th Street, Scotia, New York, U.S.A.) Oct. 17, 1930, No. 31154. Convention date, Oct. 17, 1929. Void [Published under Sect. 91 of the Acts]. [Class 39 (i).] In a method of sealing a thin metal member to glass, particularly applicable to the sealing of a thin metal window, of a chromium-iron alloy, into an X-ray tube, the edge of the metal window is first formed with a glass bead which is then sealed to the aperture in the X-ray tube. The X-ray tube has re-entrant stems 4 normal to one another, on which a tungsten copper-backed anode 2 and a combined cathode and ray-focusing arrangement 3 are carried, the X-rays being directed through the window 5. During formation of the sealing bead 5, which is of French lead glass, the metal disc 5 is held between two massive metal cylinders 8, 9, Fig. 2, clamped by means of a spring member 10, and the bead is applied from a cane 6 by means of a torch 7. The window 5 is sealed into the envelope 1 before the formation of the re-entrant stems 4 and during this process the envelope 1 is rotatably mounted on a hollow shaft 17, Fig. 4, passing through a plug 12 and a centring ring 20 and carrying one of the heat-conductive window-clamping members 19. The other clamping member 18 is carried on a rod 28 and cross-piece 30, the rod 28 being resiliently carried in a sleeve 26 which is secured to the shaft 17 by a rod 24 and clamp 25. The spring 32 serves to press the members 18, 19 together. During sealing of the window edge by the torch 33 the whole tube and fitting is rotated by means of a belt 16 on a pulley 15 secured to the hollow shaft 17. To prevent collapse of the envelope 1 air may be passed through the tube 17, e.g. by blowing, into the envelope 1 through holes 22 in the tube 17.