GB151939A - Improvements in or relating to electrical switching or circuit breaking mechanism - Google Patents

Abstract

151,939. Cutter Electrical & Manufacturing Co., (Assignees of Scott, W. M.). Oct. 2, 1919, [Convention date]. A u t o m a t i c circuitbreakers; cases; indicators. - Double-pole automatic circuit-breakers consists of a pair of independently operable circuit-breaker arms tripped by a single electromagnetic device and re-set, one after the other, by a common hand-operated resetting device operated from the exterior of the housing. The two similar current breakers which constitute the double-pole device each comprises fixed contacts 1, 2 mounted on the base 13 and connected in one side of the line, the supply leads and connexions being accommodated in a casing 11 at the rear of the base. The contacts 1, 2 are bridged bv a contact member 3 pivoted at 22 to a bracket on the base and operated through a toggle linkwork consisting of the link 23 having a fixed pivot 24, and a movable pivotal connexion 26 to the actuating lever 25, which is further pivoted at 27 to the contact-member. In the closed position, the toggle mechanism is underset and the closed position is maintained by a pivoted latch 6 engaging a pin 7 on the actuating lever 25. The latch is tripped on the occurrence of an overload in the coil 32 by the attraction of the armature 33, which carries a transversely-extending bar 8 with a lug which engages the tail of the catch of both circuitbreakers. Alternatively, the latch may be tripped by hand by. pressure on the external spring knob 34 connected through links to the armature. To re-set the switch, the external re-setting handle 43 which is mounted in the door of the casing is rotated first in one direction and then in the other; the handle-driven shaft carries two arms parallel with the switch base and terminating in rollers 41, 42. One of these rollers is brought into engagement with a similar roller 29 on one of the actuating levers and the toggle forced home and the switch locked; the handle is then reversed, bringing its other roller into engagement with the roller of the second circuit-breaker and closing the circuit. If an overload exists on the circuit, the first circuit-breaker is tripped to break the circuit even although the second circuit-breaker is in the act of closing. The re-setting handle is maintained normally in the zero position by a centralizing spring 56 and carries, externally, a pin 57 whereby it may be locked in the central position by a lock 59 passing round the pin and through an eye 58 on the door. Gravity.controlled pivoted plates 60 on the cover are moved by the actuating levers 25 so as to bring indicating disks on the plates opposite holes in the door to show the on or off condition of each circuitbreaker from the outside. The inspection door, which is hinged at the top, is securely fastened by a pivoted wedge-shaped piece on the door engaging with a projecting slotted plate 68 on the casing, and may be locked by a lock passing through a hole in the wedge-shaped piece.