GB257014A - Improvements in or relating to electric contactors or circuit-breakers - Google Patents

Abstract

257,014. Reyrolle & Co., Ltd., A., and Leeson, B. H. May 20, 1925. Sparking - preventing and are-rupturing devices; electromagnetic switches. -Electric contactors as circuit-breakers have adjacent to the contacts a conduit or chimney through which the arc vapours are blown by a jet of air which is produced by operation of the switch. As shown in Fig. 1 the switch comprises fixed contacts D<1> adapted to be bridged by a conducting bar D which is attached by a rod B<2> to the core B<1> of the operating electromagnet B. The core B<1> also carries a piston F working in a cylinder E and on release of the electromagnet core the piston is moved down by a spring G forcing a stream of air through holes E near the base of the cylinder and between the separating contacts. The arc gases are thereby blown upwards through conduits H of refractory insulating-material which have open ends adjacent to the contacts. The switch is contained within a metal casing A provided with air vents A<1>, A<2>, the conduits H being arranged to prevent the arcs spreading to the metal container. Alternatively the core itself may act as a piston. In the electromagnetic contactor shown in Figs. 4 and 5 the piston B<6> is attached to the core B‹ and works in a cylinder communicating with pipes E<5> provided with outlet slits E immediately behind the pairs of co-operating contacts D<3>, D<6>. The spring mounted movable contacts D<3> are operated when the core B<5> is released through a rod B' and rotary contact spindle J', and as the contact separate jets of air are forced between them from the slits E<6> so that the rising arc gases are forced upwardly through the conduits or chimneys H'. Each contact carries a suitable arcing barrier D<8>.