GB765252A - Combined electric switch and circuit breaker device - Google Patents

Abstract

765,252. Automatic circuit-breakers; snapaction switches; interlocking switches; switch cases. ARROW ELECTRIC SWITCHES, Ltd. Feb. 11, 1955 [March 23, 1954], No. 4100/55. Class 38(5) A combined switch and circuit-breaker device comprises a switch with manuallyoperable means to open and close contacts, a circuit-breaker with current responsive means to cause the opening of contacts and manually-operable means to reclose these contacts, and interlocking means to prevent the reclosure of the circuit-breaker contacts while the switch contacts are closed. Snap-action switches. Blade spring contacts 18 are biased towards fixed contacts 14 and operated by cams 24 on a shaft 22. Actuating member 39a, 39b secured to the shaft 22 are connected by over-centre tension springs 35 to triangular plates 32a, 32b secured on the ends of a pivoted shaft 26. Operating members 34a, 34b with push buttons 37, 36 are pivotally connected to the plates 32a, 32b. The two sets of members 39a, 39b, plates 32a, 32b and members 34a, 34b are oppositely disposed so that depression of one push button opens, and depression of the other push button closes, the contacts with a snap-action. Automatic circuit-breakers. The fixed contacts 20c, 47 co-operate with contacts 46 of fabricated bridging contact wafers having arc-extinguishing fibre discs 49. The contact wafers are mounted on a shaft 40 which is biased towards the open position by a spring 82 but normally held in the closed position by a latch 60 engaging a shoulder 52 on a latch disc 50 mounted on the shaft 40. Under overload conditions one or more bimetallic elements (indicated at 79) turn the latch 60 to release the disc 50, the spring 82 then turning the shaft 80 through 90 degrees to open the contacts. The circuit-breaker may be reclosed when the switch is open by depressing a push button 58 abutting a pin 56 projecting from the disc 50. This turns the disc, shaft and contacts 46 until the latch 60 reengages the shoulder 52. The circuitbreaker may be tripped manually on the depression 'of a trip button 67 which turns the latch 60. Interlocking switches. When the circuitbreaker trips under overload conditions, an interlocking lever 70 is moved by a spring 73 so that one of its limbs 71 abuts a shoulder 54' of the disc 50 and prevents the manual reclosure of the circuit-breaker. When the switch is opened, a releasing finger 90 secured to the shaft 22 engages and moves the lever 70 so that the limb 71 is removed from engagement with the shoulder 54 to permit the reclosure of the circuit-breaker. Switch cases. The various parts are housed in a two-part casing 10, 12 having apertures and recesses for retaining and securing the parts.