GB647465A - Improvements in and relating to high frequency electronic discharge devices - Google Patents

Abstract

647,465. Thermionic valves. BRITISH, THOMSON-HOUSTON CO., Ltd. Oct. 11, 1946, No. 30424. Convention date, April 21, 1945. Addition to 584,787. [Class 39 (i)] In a high-frequency electronic discharge device as claimed in the parent Specification a shield member 39, Fig. 2, is secured to the grid disc 29 so as to prevent material vaporized from the cathode from depositing on the insulator 34. The shield may also be attached to the anode disc of a diode, Fig. 1 (not shown), for the same purpose. The constructions described are otherwise the same as those described with reference to Figs. 1 and 6 of the parent Specification. The Specification as open to inspection under Sect. 91 also describes a construction, Fig. 3 (Cancelled), having anode 40 of steel coated with copper or silver, mesh grid 59 carried from metal wall 46 by metal cylinder 60 and an indirectly-heated cathode comprising disc 51 supported from sleeve 49 by thin cylinder 52 to restrict the flow of heat. The cathode construction also includes heat-shield 53 and an internal heater of which one lead 58 is connected to the thimble 56 sealed by glass body 57 and the other lead 55 is secured to sleeve 49 sealed to metal wall 46 via glass member 48 and solder trough 47. Insulator 44 spaces the grid and anode supports. An annular shield 61 prevents material vaporized from the cathode from reaching the glass member 48. This subjectmatter does not appear in the Specification as accepted.