GB484875A - Improvements in and relating to methods of introducing electric conductors into vacuum vessels - Google Patents

Abstract

484,875. Uniting metal to ceramic material by heat. BRITISH THOMSONHOUSTON CO., Ltd. Oct. 11, 1937, No. 27586. Convention date, Oct. 15, 1936. [Class 36] In a process for the manufacture of current leading - in conductors for vacuum vessels, of the type in which a metal ring is sealed to the circumference of a ceramic insulator by a glass flux, the glass 7 is first melted into an annular bulge in the metal ring 6 by means, such as a blow-pipe, forming an oxide coating on the ring, after which the ring is seated on the insulator 2 and together heated in a furnace having a neutral atmosphere until the glass runs, as shown at 8, into the crevice between ring and insulator. In the example, two metal tubes or rings 6 pushed upon the opposite ends of an insulator 2 are welded respectively to a flange 9 on a leading-in conductor 1 and a flange 11 on the wall 12 of a discharge vessel, this welding being effected either before or after the fusion of the glass 7. The ends of the insulator are reduced to form stops 10 against which the tubes 6 abut. In a modification, an additional conductor in the form of a Ranged metal tube is placed coaxially with the central conductor, with the flange located between the ends of two abutting tubular insulators which are coupled together by a metal ring bulged adjacent to its two ends to receive glass seals which are fused to the insulators ; the metal ring forms a terminal for the tubular conductor, which may be connected to a control grid of a vacuum discharge device.