GB568429A - Improvements in electric circuit interrupters - Google Patents

Abstract

568,429. Automatic circuit-breakers; snap-action switches ; actuation of switches. FLURSCHEIM, C. H., HOLMES, H., and METROPOLITAN-VICKERS ELECTRICAL CO., Ltd. Aug. 31, 1943, No. 14224. [Class 38 (v)] A circuit-breaker adapted to complete its closing movement with a snap action, comprises a movable contact 9 mounted on a lever 8 which is pivoted at 7 to a lever 6, in turn pivoted at 5 to the base 2. The pivot 7 is linked at 12, 13 to a bell-crank lever 14, which is pivoted at 19 to a normally-latched lever 20 and has a pin-and-slot connection 15, 16 with a press-button actuated plate 17 guided on the pivot 21 of lever 20. Also pivoted at 21 is a detent 23 which is linked at 25 to the contact-lever 8 and is formed with a surface 23a co-operating with the 0-section pivot 13 between link 12 and lever 14. When the button 18 is pressed inwards, levers 6, 8 rotate, as one, about pivot 5, compressing spring 10 by means of lower end of lever 8, until detent surface 23a engages pivot 13, so arresting the contact 9. The pivot 7 continues to move, as permitted by pivot 13 sliding along surface 23a, thus further compressing spring 10, until the pivot 13 slips past the end of the detent 23, whereupon the spring 10 rotates lever 8 about pivot 7 rapidly to close the contact 9, which is retained by the straight face of pivot 13 engaging the squared end of detent 23, Fig. 4. On automatic release by the series bimetal strip 31 or on depression of trip button 34, latch 28 is rotated about pivot 29 to release a pin 27 on lever 20 and hence pivot 13, the button 18 being restored by a wire spring 20a anchored between levers 20 and 14. The flameproof casing is adapted for mounting behind a panel.