GB476933A - Improvements in and relating to gas or vapour-filled electric discharge vessels madeof glass - Google Patents

Abstract

476,933. Discharge apparatus. ELIN AKT.-GES. FUR ELEKTRISCHE INDUSTRIE. May 14, 1936, Nos. 13722, 13723, and 13724. Convention dates, May 14, 1935, Sept. 12, 1935, and Dec. 24, 1935. [Class 39 (i)] In gas or vapour filled discharge vessels of glass in which the anodes are disposed in separate arms protruding from the main vessel, parts of the glass bounding the space behind the anode are protected from the discharge by a ceramic body which forms a surface covering for the screened parts, being of similar configuration and disposed in spaced relation thereto. Suitable materials are steatite and sintered corundum. In one form the anode lead is covered with glass and a cylindrical ceramic shield is slipped over it. In a modification, Fig. 6, the shield 3 is extended at its upper end 6 so as to protect the curved part of the envelope. One or more transverse baffle plates 4 may be added to impede the penetration of ionization into the space behind the anode. When the expansion coefficients are similar the ceramic part 6 or the transverse plates 4 may be sealed hermetically to the glass wall; in a modification, Fig. 10, the ceramic body 3 forms part of the wall, being hermetically sealed to the envelope and to the glass covering of the anode lead. The envelope may be made re-entrant as shown in Fig. 12 ; the ceramic body extends into the re-entrant portion 7, and may be provided with transverse baffles. In addition, a bell-shaped portion of the protective body may be extended around the anode, as shown, and ceramic shields or wall coatings may be provided, surrounding the discharge path between the anode and control grid. The Specification as open to inspection under Sect. 91 includes also the use of non- ceramic protective bodies. This subject-matter does not appear in the Specification as accepted.