GB826131A - Improvements in arc chutes in electric circuit interrupters - Google Patents

Abstract

826,131. Arc-rupturing in switches. GENERAL ELECTRIC CO. Dec. 13, 1955 [Dec. 13, 1954], No. 35770/55. Class 38 (5). An arc chute has two groups 50, 51 of spaced metallic plates stacked along intersecting sides of the arc chute, the groups being spaced apart to form an exhaust port 73 remote from the arc initiation point and having a relatively large venting area so that a comparatively large part of the arc produced gases will flow through the port and sweep the arc into engagement with the plates most remote from the arc initiation point. The metallic plates 53 of the group 50 are spaced by insulating strips 54 and are associated with aligned insulating plates 55. The plates 60 of the group 51 are upwardly inclined and disposed along one side of an exhaust duct 71. The switch may have two moving contacts 10 (one shown), co-operating with fixed contacts 12, 12a in narrow slots 33, 34 formed between insulating plates 37, 40, 38, the plates 37, 38 having elongated passages 43 communicating with venting pockets 42 and the plate 40 having perforations 44 to ensure the formation of arcs in both slots. The plate 40 also has slots 75 and irregular openings 76 to cause turbulence limiting the downward flow of arc gases. Magnetizable plates 67 secured to the outer side walls of the arc-chute assist the metallic plates 53, 60 in providing a low reluctance magnetic path to distort the field surrounding the arc and produce magnetic blow-out. Specification 687,886 is referred to. Reference has been directed by the Comptroller to Specification 714,979.