GB515586A - Improvements in electron discharge devices - Google Patents

Abstract

515,586. Thermionic valves. STANDARD TELEPHONES & CABLES, Ltd., VANGEEN, A. I., and WHATLING, J. H. June 7, 1938, No. 16923. [Class 39 (i)] An electron discharge device comprises a grid 15 having rectangular turns wound upon four parallel rods 10 extending from a vitreous stem 2, the grid surrounding a cathode 19 and one or more additional grids which extend between parallel insulating plates 14 supported by the parallel rods and disposed transversely thereto, a tubular anode 3 pureferably of rectangulai cross-section surrounding the grid and a hollow end cap 4 of similar cross-section having a closed outei end surrounding the insulating plate remote from the stem. The parallel rods 10 are welded to supports 11 in turn welded to a band 12 clamped about the stem 2. At the ends of the suppressor grid winding a metal tape is wound around the rods and welded in position. The insulating bridges 14 may be of lavite and are retained in position by stops 16 welded to the rods 10. The anode consists of two flanged portions welded to rods 17 held in projections 18 of the bridges. Within the suppressor grid is a cathode 19, a control grid wound on two rods 21 which extend through the upper bridge and carry a metal band 22, and a screening grid wound upon two rods 27. Two or more rods 10 extend above the electrodes and carry hollow rivets 25 by which a shielding cap 4 is secured to the rods and thereby also electrically connected to the suppressor grid. The supports 11 are bent outwardly at their upper ends and by means of hollow rivets 26 carry a two-part sheet-metal shielding skirt 5. The cap 4 and skirt 5 extend a short way into the anode and both are cut away for the passage of the projections 18. Specification 446,975 is referred to.