GB258557A - Contact device for electrical switchgear - Google Patents

Abstract

258,557. Maschinenfabrik Oerlikon. Sept. 16, 1925, [Convention date]. Contacts. - An arrangement of main and arcing contacts for heavy current switches comprises fixed contact members 7<1>, 8<1> secured to a bar 1 and movable contact members 7, 8 mounted on a common support 2. The support 2 is pivoted at 3 to a member 4 movable about a fixed pivot 5. The pivot pin 3 extends also into slots 14 in a rectilinearly movable operating rod 6 a spring 9 being interposed between a projection 10 on the bar 6 and the mid-point of the bar 2, the turning movement of which is limited by a stop 11. As the contacts are brought into engagement the arcing contacts 7, 7' first engage as shown in Fig. 1 while further movement of the operating rod brings the main contacts 8, 8<1> also into engagement. Continued motion of the rod permitted by the slots 14 causes equal contact pressure to be exerted through the spring 9 on both contacts (Fig. 2). The contacts 7, 7<1> are formed as arcing contacts and a magnetic blow out may be provided to quench the are between one or a plurality of parallel-connected pairs of arcing contacts during separation. Instead of being pivoted to the rod 4 the member 2 may be guided by arranging the pivot pin 3 to project into suitable fixed guideways. The contacts may alternatively be constructed as laminated brushes.