GB165152A - Improvements in and relating to electric switches - Google Patents

Abstract

165,152. British Thomson - Houston Co., Ltd., (General Electric Co.). March 11, 1920 Magnetic blow-outs. - An electric switch with a seriesconnected magnetic blow-out coil is provided with an arc shoot hinged to a support and so mounted as to enable the arc shoot to be swung away in either of two directions, thereby exposing the switch contacts, the shoot carrying a normally inactive magnetic blow-out coil disposed in the plane of movement of the switch contacts and adapted to be included in, the circuit with the 'arc formed between the contacts dividing the are formed between the sparking-tips, the twc portions of the arc being blown out through separate narrow paths in the arc. As applied to an automatic circuitbreaker in which the current is broken between main contacts 12, 13 with auxiliary sparking tips 29, 30 and a transversely arranged series-connected blowout coil 27, the narrow arcshoot 38 of asbestos &c. is hinged on rods 39, 40 and has a central dividing barrier 41 which supports a normally inactive blow-out coil 31, the magnetic circuit of which includes a central core 44 and thin iron plates 42, 43 mounted within the sides of the arc shoot 38, Fig. 4. As the arc is blown upwards by the coil 27, it moves from the main contacts 12, 13 to the sparking-contacts 29, 30, reaching sparking tips 33., 34 connected to the ends of the normally-inactive blow-out coil 31. As the resistance of the coil 31 is lower than that of the air gap between the sparking tips 33, 34, the arc current is diverted through the coil 31 thereby energizing this coil. An insulating division 35 divides the arc into two portions, whch are now blown out by the coil 31 through the two restricted side passages of the arc shoot.