GB741180A - Improvements in or relating to liquid immersed electric circuit breakers - Google Patents

Abstract

741,180. Liquid-blast switches. METROPOLITAN-VICKERS ELECTRICAL CO., Ltd. Feb 19, 1954 [March 18, 1953], No. 7521/53 Class 38(5) In a liquid blast switch a moving contact assembly 3 comprises a first pair of contacts 9 (one shown) which co-operate in respective arcing chambers 5 with stationary contacts 1. a further pair of contacts 20 in series with the first pair of contacts and arranged in the assembly in a further arcing chamber 18 or respective arcing chambers and a conducting bridging member 23 to interconnect the further pair of contacts. The switch shown. in Figs. 1 and 2 has six "breaks" and has a moving contact assembly 3 with parallel spaced insulating boards 4 carried on and movable with an operating rod 2. Arcing chambers 5 housed between the boards 4 each contain one contact of the first pair of contacts, i.e. a pivoted contact 9 biased upwardly by a spring 13; A further arcing chamber 18 extends transversely of the boards 4 on each side of the rod 2 and houses a pair of stud contacts 20 and a bridging member 23. Each member 23 is provided with pivoted spring-biased contact fingers 24, is carried on a plunger 29 and is upwardly biased by spring 33. When the assembly 3 is moved upwards to close the switch, as the stationary contacts 1 enter their respective arcing chambers 5, the plungers 29 come into engagement with a fixed member 35 so that the upward movement of the bridging member 23 is arrested and as the upward movement of the assembly continues, the contacts 20 are brought into engagement with the contact fingers 24. In a modified arrangement, Figs. 5 and 6 (not shown), the arcing chambers 5 are fixed around the stationary contacts and two or three further arcing chambers in the 'assembly (as 18) extend parallel to. a single supporting board.