GB390879A - Improvements in or relating to electric circuit interrupters - Google Patents

Abstract

390,879. High-tension switches. WESTINGHOUSE ELECTRIC & MANUFACTURING CO., East Pittsburg, U.S.A.- (Assignees of Dyer, L. W. ; 2324, Braddock Avenue, Swissvale, and Rawlins, H. Le G. ; 710, Coal Street, Wilkinsburg, both in Pennsylvania. U.S.A.) Nov. 10, 1931, No. 31132. Convention date, Nov. 26, 1930. [Class 38 (v).] In a circuit-breaker wherein the arc is extinguished by insulating liquid trapped in pockets formed by a number of superimposed insulating discs with insulating spacers between them the pockets constitute an elongated passage through which the arc gases are constrained to flow through the - whole length of the arc to escape through venting means arranged adjacent to the fixed contacts. In the construction shown in Fig. 1, the arc at break is drawn between the contacts 5, 6 in an arc-extinguishing chamber immersed in the oil or water tank 1. The chamber contains a number of superimposed insulating discs 37 separated from one another by insulating washers 36 so as to constitute a cellular structure through which the movable pin contact passes and from the cells of which oil and gases produced by the arc flow into the arc stream and have a deionizing effect. The circuit is broken within the first half-cycle of the break and a very rapid downward movement of the bridging contact member is effected by the double springs 15, 16 which are held in the stressed condition when the switch is closed by the engagement of a spring-pressed ball latch 29 with a slot in the rod 13. When the latch is released by the action of the tripping member 39 or a cam device 31, the springs very rapidly move down the operating rod 8 and the final movement is cushioned by the springs by the engagement of the head 25 with a collar 18. In a modification of the cellular structure, Fig. 2, the openings in the insulating discs progressively increase in size towards the vent 52. The Specification as open to inspection under Sect. 91 describes also an arrangement in which oil is trapped in the chambers of a cellular structure and is forced by the arc pressure from one chamber to another instead of being forced through a common vent. This subject-matter does not appear in the Specification as accepted.