GB287055A - Improvements in electrode structures for electron discharge devices - Google Patents

Abstract

287,055. British Thomson-Houston Co., Ltd., (Assignees of Nolte H. J., and Relyea, W. 1.). March 12, 1927, [Convention date ]. Vacuum tubes.-A spider attached to the grid support wires carries an insulating rod, one end of which has means for centring the grid-cathode structure from the anode, and the other end carries a tensioning spring for the cathode filaments. As shown in Fig. 2, extensions of the support wires 6 for the grid - are braced by cross-wires 9 and flat metal collars 10. A quartz rod 16 is spaced by spiders consisting of braces 15 secured to the wires 6 and collars 12 bolted in grooves in the rod. A metal plate 19 spaces the rod from the anode 1. A plate 23, attached to the spring 20, has spring fingers which engage in a groove in the rod, and may be secured therein by a wire. The spring of the plate 23, collars 12 and plate 19 along the rod is approximately proportional to the potential differences between the cathode, grid, and anode. The other end of the spring is secured to an hexagonal insulating plate 24 having perforations through which pass the filament sections 21 and U-shaped support 29. The sections are secured by wire to the supports 29 which prevent overheating of the plate 24. The Z-shaped supports 28, Fig. 3, tor carrying the upper ends of the filament sections, are mounted on each of two leads 26, and their lower ends are arranged regularly in alternate positions. The arrangement of filament sections is such that displacement due to the magnetic field produced by the filament current is avoided. The wires 6 between the ends of the grid are braced by wires, not shown, the split ends of which are coiled around the wires 6. A wire screen, not shown, is mounted on the upper end of the wires 6 to protect the glass portion of the envelope from bombardment. Specification 258,298 is referred to.