GB239736A - Improvements in electric discharge tubes - Google Patents

Abstract

239,736. General Electric Co., Ltd., Bartlett, A. C., Le Rossignol, R., and Gardiner, H. W. B. Oct. 30, 1924. V a c u u m tubes.- Anodes for high-power rectifiers and other discharge tubes in which the anode forms part of the hermetically - sealed envelope comprise two or more hollow parallel cylinders substantially closed in cross-section and each surrounding a straight portion of the cathode. A mica or other insulating tube within the envelope may be secured to one end of the anode and formed with means for supporting tensioned supports for the cathode filament at the end remote from the filament leads. The anode 11, Fig. 1, may be formed from a circular onepiece tube of metal such as copper by depressing the central part 24, Fig. 3, at each side to form two cylindrical chambers 23. Each chamber 23 surrounds a straight part 20 of the filament, the two parts 20 being connected at one end by a bridge 21 and supported at the other end from a foot-tube 16 by leads 19. The bridge 21 is carried by wires 25 supported by a cup 26, springs 27 acting against nuts 28 tensioning the parts 20 and the wires 25 being guided in perforated discs at the apices of wire tripods 29 on the cup 26. The cup 26 is carried by a mica tube 30 having an external ring 21 and secured by means of a flanged tube 32 and studs 33 to a metal ring 34 inserted in one end of the anode 11. A jacket 38 to which the anode lead may be connected is secured by welded flanges 36, 37 and a ring 39 to the anode. Glass tubes 12, 13 completing the envelope are sealed to the anode by nickeliron or like metal rings 14, 15 welded or soldered to the anode with the glass fused on, the foot 16 being sealed to the tube 12 and the envelope then evacuated through the tube 13 and sealed off. A guard ring 41 fitting over the ring 34 prevents discharges from the studs 33, and this ring 41 and a metal ring 35 inserted in the other end of the anode protect the glass near the joints with the metal. In a modification, the anode comprises parallel cylindrical metal tubes connected together at the ends and with the envelope completed by vitreous end-pieces. Specification 223,293 is referred to.