GB636883A - Improvements in and relating to arc extinguishing devices for electric circuit breakers - Google Patents

Abstract

636,883. Arc-rupturing in switches. BRITISH THOMSON-HOUSTON CO., Ltd. Sept. 16, 1946, No. 27745. Convention date, Sept. 17, 1945. [Class 38 (v)] An arc shoot for a heavy-duty D.C. circuitbreaker such as disclosed in Specification 565,823 and having fixed and movable arcing contacts 3, 5, comprises high melting-point magnetic arc runners 12. 13 situated in two rear compartments formed by insulating plates 8, 9 and a shaped insulating barrier 30, and having lower portions 14, 15 extending into a front compartment formed by insulating plates 7, 8. The plate 8 has elongated openings 31, 32 extending from a base 33 of the barrier 30 and situated above and parallel to the arc runners. The arc runner 12 is mounted on a terminal 1, insulating fillers 16, 17 and a replaceabove slidable filler 18 being interposed between it and insulating end spacers 10, 11. The arc runner 13 is supported in insulating spacers 21, 22 between baffle plates 23 and has its upper end 28 bent through 90-180 degrees to cause movement of the arc root, thereby minimizing localized heating of the runner with consequent metallic vaporization. When the arc rises up the runners under the action of the magnetic flux, its ends pass through the openings 31, 32 into the rear compartments, leaving the main body in the front compartment separate from the metal-contaminated ends. To prevent reformation of the arc outside the shoot, the plate 8 is made larger than plates 7, 9.