GB224980A - Improvements in electric circuit breakers - Google Patents

Abstract

224,980. English Electric Co., Ltd., and Morris, F. Aug. 29, 1923. Automatic circuit-breakers ; switches actuating. - In a breaker adapted either for rapid or slow operation and comprising three members pivotally connected together and forming between them a compound toggle, acting as a principal toggle when two adjacent members are held rigid by a catch device and permitting the two members to act as a secondary toggle when the catch is out of action, the catch is carried by the two members, only one of which moves during the rapid action of the breaker. The movable contact 2 is carried on a lever 3 pivoted at 4 to a lever 6, which is in turn pivoted to the framework at 8 and has an extension 38 engaged by a biassing spring 40. The compound toggle comprises link 10, pivoted at 11 to lever 6, link 13, and lever 14 pivoted to the frame at 15. The elements 13, 14 may be latched to form a principal, toggle or single element by means of a light projection 20 on the former engaged by a relatively heavy latch 17 pivoted at 18 to the latter and controlled by a spring 19, and, with the parts 13, 14 so latched together, the breaker could be operated' as a slow action switch by rotating the lever 14 manually or otherwise to collapse the principal toggle. A quick break is imparted by tripping the latch 17 so that, lever 14 remaining stationary against stop 22, the spring 40 breaks the toggle 14, 13 and moves the lever 6 against stop 39. To re-close. the lever 14 is first moved clockwise until the latch 17 engages projection 20 and the lever 14 is then moved back to reset the principal toggle consisting (of link 10 and link 13 and lever 14 together. A. single operating lever 23, pivoted at 15, can operate the breaker with a quick break by means of a U-shaped slot 24, the left-hand limb of which engages the tail 26 of the latch 17 to open the switch. Further movement of this limb reengages the latch 17 and reverse movement of the lever causes the right-hand limb thereof to engage the lever 14 to re-set the 'breaker. Electromagnetic means for tripping comprises a lever 33, pivoted at 15, and carrying a boss 34 which engages the tail 26 of the catch 17. This lever is operated from a rod 32 connected to a bell-crank lever 29 which carries an armature 28 co-operating with a pole-piece 27. A setting screw 36 and scats 31 are provided for varying the tension of the control spring 35. It will be seen two modes of opening are possible, one by moving the membe.r 14 by hand when a slow motion is suitable, the other being a rapid action by tripping means.