GB372080A - Improvements in or relating to methods of manufacturing mercury vapour filled electron tubes - Google Patents

Abstract

372,080. Electric discharge tubes. TELEFUNKEN GES. FUR DRAHTLOSE TELEGRAPHIE, 12, Hallesches Ufer, Berlin. April 22, 1931, No. 11953. Convention date, April 22, 1930. [Class 39 (i).] In an electronic discharge tube of the kind having a filling of mercury vapour derived from a predetermined quantity of mercury contained in one or more small retaining vessels in communication with the interior of the tube, each such vessel is in the form of a capillary tube centrally enlarged and open at one or both ends, the mercury being released therefrom by the application of heat, derived e.g. from high frequency currents or from an external flame. Thus a capillary tube may be heated locally and subjected to internal pressure to provide enlargements E, Fig. 2, the tube being then filled with mercury and cut into sections such as K, Fig. 1. One or more such sections may be fixed to a metallic part of the electrode system, e.g. to the anode A or, as shown, to a metal plate M above the anode. Alternatively, the one or more sections K may be introduced into the pump lead of the discharge tube.