Improvements relating to series-trip mechanisms for heavy-current electric circuit-breakers

摘要

777,723. Automatic circuit-breakers. REYROLLE & CO., Ltd., A: June 28,1955 [June 29, 1954], No. 18992/54., Class 38(5) To reduce the size of an overload tripping mechanism and to improve the speed of operation the cross section of a portion 14 of a main conductor 10 is reduced to less than that required to carry the rated overload current without overheating and means are provided for removing any excessive heat generated, the reduced portion being closely surrounded by a magnetic yoke 15 having an armature 17 connected to the tripping means of a circuit- breaker. In the arrangement shown, conical portions 13 and end portions 12 act as "heat sinks" for removing heat from the portion 14. The yoke 15 and armature 17 may be formed by cutting a magnetic cylinder along a plane parallel to its axis. The armature 17 is guided by means of pivoted arms 18 and is connected to a link 20 which slides against the bias of a spring 26 in a guide 23 carried on supporting frame 24, the link being connected by an insulating rod 21 to a trip latch (not shown). The yoke 15 may be supported by an insulating block 16 between rectangular sections of the main conductor 10.