GB224047A - Improvements in or relating to electric switches - Google Patents

Abstract

224,047. Denny, C. W. Sept. 20, 1923. Arc-rupturing devices; oil switches; electromagnetic switches; automatic circuit-breakers.- The contacts of electric switches are arranged so that a number of breaks in series are produced when the movable current-carrying member bearing the movable contacts is operated to break the circuit. In the oil switch shown in Figs. 2 - - 5 are stationary terminals E, E<1> and a movable bridging member C. On the terminals E, E<1> are mounted pairs of contact fingers B<1>, A' electrically connected thereto and pair of contact fingers B<2>, B<3> and A<2>, A<3> connected to sleeves F, F<1> mounted on but insulated from the terminals E, E<1>. On the movable bar C are contact portions at each end (Fig. 5) co-operating with the fixed contact fingers B<3>, A<3> and contact sleeves C<1>, C<2> mounted on but insulated from the bar C and adapted to co-operate with the other pairs of fixed contact fingers. Thus when the bridging bar is operated to open the switch three series breaks occur at each end of the bar. In. sulating barriers G are secured to the sleeves C<1> C<2> to prevent interaction between adjacent arcs. A similar arrangement of contacts in an air. break switch is also described. In the knife switch shown in Fig. 9 fixed contact fingers A<1> are connected to one terminal E<1> and contact fingers A<2>, A<3> are connected together but insulated from this terminal. The knife blade C connected to the other terminal E carries an insulated sleeve C<2> adapted to co-operate with fixed contacts A', A<2> so that three simultaneous series breaks occur when the switch is opened. A similar contact arrangement is also described in an electromagnetically operated contactor switch and an automatic circuit-breaker.