GB555511A - Improvements in and relating to automatic electric circuit-breakers - Google Patents

Abstract

555,511. Automatic circuit-breakers. ARROW ELECTRIC SWITCHES, Ltd. Jan. 5, 1942, No. 138. Convention date, Jan. 15, 1941. [Class 38 (v)] A circuit-breaker particularly adapted for mounting with others in a casing in the manner described in Specification 555,537, comprises a moulded, flat-sided, insulating base 10 divided by a longitudinal partition 16 and transverse passage 20 into four circuit-breaker containing cavities. Passage 20 contains busbar 22 having two pairs of ears 22a, 22b overlying and securing the upper ends of supports 82 of bimetal latches 7a. A handle 30 is pivoted on a pin 38 in bearings closed by the fibre liner 32 of the cover 34. To each is pivoted at 40 a C-shaped carrier 42 of a silver contact 44 which can be operated "on" and "off" as a dead-centre spring type of switch and can be released on overload by deflection of the bimetal latch 74. The spring 70 is anchored between a hook 72 and the pivot 64 and its end 71 is bent round against the barrier 100. Pivot 64 is supported in slots in the base and supports a latch 52 comprising a pair of limbs one on either side of the carrier 42 and united by a yoke which is slotted at 60 to receive the carrier. A projection 90 on the latter engages a slightly-curved surface 62 of the yoke and one limb is extended upwardly at 57 to take in a hole 76 at the end of the bimetal latch. In manual operation between on and off positions, as depicted in the two mechanisms of Fig. 2. the pivot 40 moves across the line of centres 38, 64 straining and relaxing the spring 70 which holds the contact carrier in both extreme positions. When tripped, the latch 52 moves clockwise under the action of the spring, and is reset by moving the lever 30 "off," whereupon movement of the lever to the "on" position recloses the breaker. The Specification as open to inspection under Sect. 91 included also means for adapting the individual breakers to single or multi-pole circuits and for providing an adjustable threepoint support for the bimetal latches. This subject-matter does not appear in the Specification as accented, but forms the subject-matter of Specification 555,537.