GB277123A - Improvements in electron discharge devices - Google Patents

Abstract

277,123. Standard Telephones & Cables, Ltd., (Western Electric Co., Inc.). June 12, 1926. Addition to 255,320. Vacuum tubes. - In electron-discharge tubes having a shield 17 surrounding the leading-in wires to the inner electrodes and serving to prevent corona discharges between the anode 11 and the supporting structure of the other electrodes. as described in the parent Specification, the shield is sealed by fusing it to a stem 16 of the vitreous envelopes. The seal may be of the ordinary kind shown in Fig. 1, or the shield may be provided with projections 40, Fig. 3, which are fused to the glass stem 16. A wire grid 22 may be mounted on rods 21 carried by a ring 19 having a groove into which the end of the shield 17 is fixed, the cathode supporting-rod 27 passing through the ring and being attached to a metal disc 26. This disc is carried by a rod 25 clipped to a glass extension 23 of the stem 13, and nearly closes the end of the shield 17 to prevent its interior from being overheated. In the case of a two-electrode tube, the ring 19 is replaced by a disc 38, Fig. 2, which completely closes the shield 17 and carries the cathode. Long leading- in wires 31 carried by the disc 26 or the disc 38 are connected to outer leading-in wires 33 by flexible lengths of copper braid 32. The wires 33 are sealed into metal thimbles 15 either directly solder 34, or by screwing them into tapped recesses in the thimbles and running solder into the joints during the preglowing of the copper to remove occluded gases. The anode is fused to the glass envelope as described in Specification 202,047.