GB630136A - Improvements in electron discharge device - Google Patents

Abstract

630,136. Glass to metal seals. SYLVANIA ELECTRIC PRODUCTS, Inc. Aug. 16, 1946, No. 24518. Convention date, Aug. 22, 1945. [Class 36] [Also in Group XL (a)] A method of manufacturing a discharge device of the type in which the envelope consists of metal discs 5, 6, Fig. 11, and glass envelope portions 1, 2, 3, comprises effecting all the seals between the discs and the glass portions simultaneously, pressure being applied axially to the composite structure during sealing, and while the glass is plastic the discs are guided toward one another until further movement is prevented by stops. Preferably, members 18, 19 Fig. 11, form the guiding means and the members 19 form the stops; the members 18, 19 pass through holes 8, 9, Fig. 4, in the discs 5, 6. Glass tubing 1, 2 is centred by member 13 and sleeves 20, 21 of ceramic material. The glass tube 3 is centred by a pair of pliers, Fig. 13A (not shown). After sealing the active electrode parts are riveted or screwed on to the inner peripheries of the discs. The anode proper 48, Figs. 5, 10, is cup shaped and has a flange formed with holes 50, Fig. 5, and slots 51 which register with holes 9, 8 respectively in the disc 5. An outer anode ring 52, Fig. 24, is soldered to the disc 5 after sealing. The grid frame 53, Fig. 7, similarly has holes 55 and slots 56. The indirectly heated cathode 73, Fig. 24, is sealed through header 71. Rivets 58 may have extensions which extend to the proximity of the grid or (as shown) through holes 8 in the grid disc 6 so as to capacitatively couple the electrodes and may also couple resonators associated with the electrodes. If the anode and grid discs are very thin they may be specially shaped to reinforce them, Fig. 12 (not shown). A number of units for assembly and sealing may be mounted on the intermittently rotatable turret of a machine, for quantity production. Any of the electrodes may be composed of two or more parts in addition to the discs.