GB499681A - Electron discharge devices - Google Patents

Abstract

499,681. Thermionic valves. STANDARD TELEPHONES & CABLES, Ltd. Nov. 5, 1937, No. 30380. Convention date, Nov. 13, 1936. [Class 39 (i)] The cathode of a device for dealing with highfrequency oscillations, is formed with a flat perforated surface covered with emissive material on the side remote from the anode. The Specification describes two constructions of diode generator. Fig. 1 shows an arrangement comprising an envelope formed in two parts, one of which is a metal cylinder 14 in one piece with a coaxial inner cylinder 13 forming the anode. The cathode 18 is a perforated disc coated with emissive material on its upper face and forming the end of a cylinder 17 coaxial with the cylinder 13. The cylinder 17 is formed with a flange 19 which is held against a ring 21 resting on a shoulder on the anode structure by means of a screwed ring 29, a washer 30, and insulating washers 20, 28. Within the cylinder 17 is a heater 22 the leads of which pass through a glass portion 10 of the envelope sealed to the portion 15. One of the leads is connected to the cathode by means of a wire 26 clamped between the flange 19 and the insulating, washer 28. The cylinder 17 is grooved to obstruct conduction of heat. Fig. 5 shows the flange 19 of the cathode cylinder 17 welded to a portion 34 of the envelope formed with a flange 35 and an inner cylindrical wall 36. The anode 13 is formed on the end of a cylinder 41 having a shoulder 40 accommodating an insulator 39 by which it is separated from the wall 36. The cylinder 41 is made in one piece with a second portion 42 of the envelope, the portions 34, 42 being sealed to a glass ring 43.