Improvements in spring operating mechanisms for electric switches or circuit-breakers

摘要

545,061. Automatic circuit - breakers; actuation of switches. BRITISH THOMSONHOUSTON CO.; Ltd. Jan. 10, 1941, No. 382. Convention date, Jan. 10, 1940. [Class 38 (v)] A circuit-breaker opening or closing spring surrounds, and is anchored to, a pair of drums adjacent faces of which are provided with trippable latching means whereby the spring-energy - may be released. The arm 22 connected to the contacts is keyed to tubular extension 21 of drum, 20, which is rotatable on extension 17SP1/SP of shaft 17 to which are keyed the other drum 19 and operating arm 18. One end 30 of spring 24 takes in slot 31 in drum 20 whereas the other end 25 can be passed through any one of a number of holes 26 in a flange 27 and pinned at 28. Drum 19 carries a trippable latch 32 which is urged by spring 37 against a stop 36 on drum 20, in which position a surface thereon fits over a roller 38 on a shaft 39 and prevents clockwise rotation of 20, as seen in Fig. 7. Reverse rotation is prevented by a further latch on drum 19 engaging recess 43 in drum 20. When latch 32 is tripped by energizing the solenoid 48, spring 24 rotates drum 20 clockwise and brings arm 22 into the released position, the solenoid being de-energized by a switch 52 operated from the drum through levers 53, 54. During the releasing movement, arm 18 is held against movement in one direction by engagement of parts 56, 57 and in the other direction by an over-centre arrangement (not shown) attached to the operating rod which is pivoted to arm 18. Also during the releasing movement, cam surfaces 47, 47SP1/SP engage the drum-latches and hold them back. To restore the breaker, arm 18 is rotated clockwise, winding the spring 24, until the latch 32 reengages the roller 38. On reversely rotating arm 18, the arm 22 is restored to the position shown.