GB940108A - Electric circuit breakers - Google Patents

Abstract

940,108. Electrically released switches; snap action switches; contact members for switches. WESTINGHOUSE ELECTRIC CORPORATION. April 12, 1962 [May 19, 1961], No. 14149/62. Heading H2B. A circuit breaker (Fig. 3) comprises a contact assembly 13 as described in Specification 940,109, an arc extinguishing structure 15, manual operating mechanism 17 and a trip mechanism 19 assembled between insulating side plates 21 and housed in an insulating casing 5 (Fig. 2). The operating mechanism consists of two toggle levers 38, 39 and tension springs 67 movable overcentre by a pivoted handle 63. The trip mechanism comprises a bimetal 115 and an electromagnet 123 and pivoted armature 102 both operative on overload to rotate a lever 73 to allow a latch 87 to drop into a flat on its shaft 75 and to release a pivoted latch arm 43 and thus collapse the toggle 38, 39 whereupon the contacts 23, 25 open and the handle 63 moves to a central position. To reset the strip mechanism handle 63 must be moved first to its off position when an abutment 140 thereon forces the arm 43 back into engagement with its latch 87. The arc extinguishing structure consists of a conducting arc runner 162 in connection with the fixed contact 23 and a number of plates 151 which may either be of conducting magnetic material to divide the arc or of insulating material to elongate it. The two part casing 5 is held together by hollow rivets 12. Multi-pole breakers (Figs. 16, 17, not shown) may be made up by assembling several single pole breakers side by side and passing long rivets through the hollow rivers 12. Knockouts (Fig. 1, not shown) are provided in the sides of casing 5 to accommodate inserts which link the shafts 75 of adjacent breakers and handles 63 are linked by ties engaging in openings 177 therein.