GB650560A - Grid-controlled gaseous electron discharge device - Google Patents

Abstract

650,560. Thermionic valves. SYLVANIA ELECTRIC PRODUCTS, Inc. Jan. 30, 1948, No. 2898. Convention date, Feb. 1, 1947. [Class 39 (i)] The grid of a gas-filled electron discharge device, such as a thyratron having a long and slender cathode, is solid and has one or more apertures arranged transversely to the cathode, so that small errors in the positioning of the electrodes will not affect the performance of the device. In Figs. 4 and 5, the grid 18 has three apertures, and when the device has fired, the resultant conduction from the cathode 20 to the anode 22 is through one aperture only. In Figs. 6 and 7, the grid 26 is U-shaped and arranged around the cathode 28 which has only a small emissive coating 30 arranged opposite a single aperture in the grid. An auxiliary negative grid comprising the two arms 38 of a U-shaped rod is arranged between the grid 26 and the rod-shaped anode 42. The grid 26 may, alternatively, be arranged to electrostatically screen the anode instead of the cathode, and the grid aperture may be perpendicular to the cathodes as shown, or at some other substantial angle thereto. The cathode, anode, and grid 38 extend through upper and lower mica locating members 50, 52, through which also project rods 32, 36 to which the solid grid 26 is secured, the rods 32, 36 being lap welded to dummy and lead-in conductor rods 56, 37 which, together with rods 40, 44 to which the grid 38 and anode are respectively lap-welded, support the lower member 52. The cathode is connected by a tab 48 to a similar lead 46. The upper member 50 is held by staking the rods above it and by welding getter-strip 54 to rods 32 and in contact with the member.