GB491685A - Improvements in or relating to electron discharge devices - Google Patents

Abstract

491,685. Discharge apparatus. STANDARD TELEPHONES & CABLES, Ltd. Aug. 10, 1937, No. 22008. Convention date, Oct. 7, 1936. [Class 39 (i)] The enclosing vessel of an electron - discharge device is composed of several parts secured together, one part supporting one or more electrodes of an electrode assembly and one or more contact members adapted to be grasped by contacts of electrodes of the assembly supported by another part, the contacting device being capable of movement lateral to that necessary to bring the parts together, whereby the electrodes carried on the separate parts may be aligned with each other. In the form shown, two electrode assemblies are carried by a structure consisting of two concentric cylinders 24, 27 each having top and bottom closure members, the outer cylinder 27 being metallically connected to a central post 13 from which the inner cylinder 24 is carried by insulators. The filamentary cathodes 11 are carried by the cross-bar 12 and J-shaped springs 15. The anodes 40 are supported by leads 44 passing through the top of the envelope. Each assembly forms a pentode comprising a control grid 21, Fig. 3, of U-shaped parallel wires secured to arms 17 extending from support rod 20, screen and suppressor grids 23, 26 of similar construction secured to cylinders 24, 27 respectively by welded bracing wires 25, 28, and a hollow crescent-shaped anode 40. The suppressor grids have solid end pieces 39. The connection to the shield grid is made by a blade 54 attached to the lead 53 and engaging two resilient strips 50 extending between studs 47 welded to the inner cylinder 24. Resilient wires 69 press against the insulators 48 surrounding the studs 47 and permit a slight rotary adjustment of the cylinders 24, 27. A shielding flange 38 extends from the bottom of cylinder 27. In a modification, the filament is a flat strip and the anodes are of carbon with three diverging flanges, the support rod passing through the centre flange. The cylinders 24, 27 act as a large surface condenser connected between the screen and suppressor grids.