GB520635A - Improvements in or relating to the sealing of electric conductors through quartz - Google Patents

Abstract

520,635. Sealing metal to quartz. THERMAL SYNDICATE, Ltd., and REYNOLDS, F. Oct. 26, 1938, No. 30899. [Class 36] In a vacuum-tight seal between an electric conductor and fused quartz wherein the conductor comprises one or more thin strips 1 of Mo, W, or other suitable metal or alloy, the relatively thick inlead or inleads 2 are secured to the fused quartz by surrounding them with crushed, quartz 4 which is then heated to sintering temperature. In Fig. 3, the strip and inleads are inserted in a quartz tube 3 which is collapsed on to the strip except at its ends; the quartz 4 is inserted, the tube 3 exhausted, and the tube is heated by an oxy-coal gas or oxy-hydrogen flame adjacent each end of the seal until it collapses, on to the crushed quartz, fuses the outer part of the latter, and sinters the inner part, the ends of the tube being then cut away. In-Fig. 5, the strip 1 is first sealed to a quartz tube 5 and is then inserted into a quartz tube 6, crushed quartz 4 being then inserted and heated as before. The inleads may be of flat, round or other section and may be integral with the strip 1, the latter, being first flattened, and then reduced in thickness by grinding or etching ; the inleads may have projections or be otherwise roughened.