GB216896A - Improvements in or relating to electric discharge tubes having an incandescent cathode, an anode and one or more grid-electrodes - Google Patents

Abstract

216,896. Naamlooze Vennootschap Philips' Gloeilampenfabrieken. June 2, 1923, [Convention date]. Vacuum tubes.-A glass tube sealed to the wall of a thermionic valve ends in a number of adjacent glass tubes, of which one at least carries and seals the support for a grid and the other tubes carry and seal the supports for the eathode. As shown in Figs. 1 and 2, the tube 3 sealed to the tube 1 is extended to form three tubes 4, 5, 6, the ends of the tubes 4, 6 being sealed by discs or caps 7, 9 carrying the supports 24, 25 for the cathode 26, and the end of the tube 5 being sealed by a disc or cap 8 having a standard 11 carrying a table 12 to which supports 13 for the grid wire 15 are secured, for instance, by nuts when the supports are of nickel, chrome-iron, or molybdenum, but when of tungsten the supports are inserted in holes in the table and secured by set-screws. The other ends of the supports are secured to a disc 14. The discs 7, 8, 9, standard 11 and table 12 are preferably of chrome-iron. The table 12 is recessed to receive, the supports 24, 25 and is arranged so as to prevent electrons from passing into the tube 1. A V-shaped cathode may be held in tension by securing the middle to a rod 30, Fig. 4, which slides in a glass tube 29 secured by a clamp 28 to a standard 27 mounted on the cathode support 24. In use the valve is mounted with the metallic portion 2 forming the anode extending downwards. More than two electrodes may be mounted on the glass tubes.