GB1296337A - - Google Patents

Abstract

1296337 Vacuum switches SIEMENS AG 16 July 1971 [16 July 1970] 33618/71 Heading H1N A vacuum circuit-breaker 2 with separable contacts 6, 7, is provided with three arc electrodes 11, 16, 17, forming a system into which the arc travels and is extinguished without damaging the insulating body 5 or spattering it with metal vapour, the electrode 11 being mounted on contact 7 and having a cylindrical wall disposed inside and coaxial with the doublewalled electrode 16, which is at the same potential as contact 6, and the electrode 17 being at the potential of contact 7 and defining with electrode 16 an arc path portion extending radially away from the annular cross-section path defined by electrodes 11 and 16. When the arc enters channel 27 it is driven back by a strong loop action. One or more electrodes may have slits 35, Fig. 2 (not shown), for rotating the arc. An insulating ring-shaped gap 34 may be provided in the region of the upper end 29 of the electrode 16, and the electrode parts bonding the gap may be rounded by a beading, Fig. 3 (not shown), or overlap, Fig. 4 (not shown). Thus a loop action causes the arc to move rapidly up to end 29 of electrode 16. Electrode 11 may be shortened and electrode 17 varied in shape to provide an arrangement as in Fig. 5, with outer electrodes 39 and 40 replacing electrodes 17 and 16 and defining a channel 44 for the arc. The ring-shaped gaps 28 and 34 are offset from one another and no visual communication exists between these gaps, forming the channel inlet, and the point at which the channel opens into the insulating body 5.