Improvements in and relating to means for the automatic regeneration of the vacuum in vacuum containers

摘要

351,641. Maintaining high vacua. INTERNATIONAL GENERAL ELECTRIC CO., Inc., 120, Broadway, New York, U.S.A.-(Assignees of Allgemeine Elektricitats Ges.; 2, Friedrich Karl-Ufer, Berlin.) April 24, 1930, No. 12694. Convention date, April 24, 1929. [Class 8 (i).] The vacuum in a container more particularly a high vacuum switch container is maintained by making use of a relay, controlled by the positive ion current which flows when the pressure reaches a predetermined limit, which connects a heating device for the vaporization of a regenerating substance such as calcium, barium, or magnesium. The container 15 has an extension in which a glass tube 1 containing the regenerating substance is situated, and an extension 5 enclosing a grid 13, a filament 12, and an electrode 14. When the vacuum in the container is reduced, a sufficient current flows between the grid 13, and the electrode 14, to operate a relay 4, closing the circuit of a heating filament 2 and resulting in the vaporization of the regenerating substance which reduces the pressure in the main container. An electrode 7 may be introduced close to the filament 2 and positively charged with respect to it, so that the emission of electrons from the filament 2 is accelerated to bring about ionization of the gases and vapours. The electrode 7 may be continuously charged or only when the relay 4 operates. To prevent the vaporization of the regenerative substance in the tube 1 during the initial evacuation of the container 15, the tube is at first sealed and heated by means of the filament 2 to open at a weak spot 3 after the container 15 has been treated.