GB616229A - Improvements in electron discharge devices - Google Patents

Abstract

616,229. Thermionic valves. WESTERN ELECTRIC CO., Inc. Aug. 30, 1946, No. 26181. Convention date, Sept. 24, 1945. [Class 39 (i)] An electron discharge device of the multigrid type has insulating spacer members 22 and 23 at either end of the electrode system, the grids being secured to the upper member 22 and free to expand downwards so that the initial alignment of the grid laterals is maintained during operation. The embodiment described is a beam power type device, comprising a central cathode 16 with internal heater 17 and insulator 18, two-part anode 19 secured via flanges 20 and pins 21 to the spacers, and beam-forming plates 27. Concentric grids 30 and 32 are wound respectively on support rods 31, 33 secured to the upper side of the upper spacer. Rods 31 are held in loop portions 36 of a pair of angularly bent straps 34, 35 whose ends are formed to grip two pins 38 riveted to spacer 22. Similarly, rods 33 are secured by straps 39, 40 to riveted pins 41. Straps 34, 35, together with anodes 19, may be blackened to increase heat dissipation. Lower spacer member 23 is mounted rigidly on a pair of conductor in-leads, further in-leads being flexibly connected to the grid rods. The whole unit is mounted inside a vitreous envelope by side mica spacers (Fig. 4, not shown), locking on the equilaterally spaced ears 43 on spacers 22, 23. Locating holes such as 49 in the respective spacers enable a locating rod test to ensure selection of correct spacers during assembly.