GB553350A - Improvements in or relating to metal-to-glass seals of medium size - Google Patents

Abstract

553,350. Sealing metal to glass. LIEBMANN, G., and CATHODEON, Ltd. Nov. 20, 1941, No. 14915. [Class 36] In sealing metal tubes of small diameter through the walls of a glass envelope in a vacuum-tight manner, the tube or tubes is or are secured to a metal disc or thimble the periphery of which lies outside the external surface of the tube or tubes, and the glass is sealed to that part of the disc or thimble which lies outside said external surface that part of the disc or thimble lying within the tube or tubes having an aperture or bush therein, in or to which a beaded leading- in conductor or a glass exhaust tube is sealed. In Fig. 1, nickel &c. tubes 3, 4 of the same or different diameters, are welded on opposite sides of a chrome-iron, platinum, copper, molybdenum or iron-nickel-cobalt disc 2, the edge of the disc 2 being sealed to the glass envelope 1 before or after the welding of the tubes 3, 4 thereto. In Fig. 2, a thimble 8 has its preferably thinned edge sealed to the envelope 1, and the tubes 3, 4 are pushed respectively over the outside and into the inside of the thimble and preferably welded thereto. In each case, the disc or thimble is apertured, or has a bush 5 pressed out therefrom, and has a lead-in wire 6 sealed thereto by a glass bead 7 either before, after or simultaneously with the other operations. More than one lead-in wire may be similarly sealed. Either of the tubes 3, 4 may be omitted. In another form, in place of the lead-in wire, a glass exhaust tube is sealed to the disc or thimble ; the tube 3 is then preferably short to permit sealing-off of the exhaust tube, after which a further metal tube may be fitted into or over the tube 3 and welded &c. thereto.