GB373471A - Improvements in and relating to vacuum electric circuit interrupters - Google Patents

Abstract

373,471. Vacuum switches and fuses. BRITISH THOMSON-HOUSON CO., Ltd., Crown House, Aldwych, London.-(Assignees of Prince, D. C.; 1424, Wendell Avenue, Schenectady, New York, U.S.A.) July 14, 1931, No. 20256. Convention date, July 14, 1930. [Class 38 (v).] A vacuum circuit interrupter is provided with one or more grids or barriers arranged in the gap between the electrodes and electrically insulated so as to be free to assume any potential. The breakdown voltage of the interrupter is increased by the use of such a grid. As shown in Fig. 2 applied to a vacuum or low pressure switch with electrodes 10, 11 supported by yieldable portions 16, 17 of the casing to allow of longitudinal movement, a wire-mesh grid in the form of a disc 14 is supported by the walls of the casing in the gap between the electrodes. The grid has a central contact portion which is engaged by both electrodes in the closed position of the switch. As applied to a vacuum fusible cut-out, Fig. 2, the fuse wire is arranged between tungsten electrodes for D.C.. and nickel or copper electrodes for A.C., the electrodes being covered by shields 2<1>, 31 at the sealing points. A pair of grids 7, 8 supported from the container and spaced equidistantly from the electrodes and from one another increase the breakdown voltage of the fuse.