SELF-ADJUSTING CIRCUIT BREAKER WITH ROTATING TRIP ASSEMBLY

摘要

1516153 Automatic circuit breakers WESTINGHOUSE ELECTRIC CORP 15 Sept 1975 [18 Sept 1974] 37802/75 Heading H1N In a moulded case circuit breaker with a trip and latching mechanism having a latch member 45, 66 movable into latching engagement with a latchable member 33 to hold it in a latched position and movable out of latching engagement with this latchable member 33 to trip the circuit breaker in response to overload currents exceeding a predetermined level, the level at which the circuit breaker trips being settable by alteration of the amount of latching engagement between a first part 66 of the latch member and a latch 81 on the latchable member 33, the setting of the amount of latching engagement is maintained constant in spite of dimensional changes in the casing 11 by providing on the latchable member 33 a reference surface 85 against which a second part 45 of the latch member is resiliently held by a spring 83. The first part 66 of the latch member is an armature which co-operates with a magnetic yoke 65 for electromagnetic tripping of the circuit breaker and the second part 45 of the latch member is a bimetal strip for thermal tripping. The setting of the amount of latching engagement is effected by a screw 77 which changes the distance between the two parts 66 and 45 of the latch members, this member having pivots 71 which engage in holes in the casing. A maximum setting of the latch may be provided by a latch stop 87 on the latchable member 33. In an alternative embodiment the first part 66 of the latch member deflects a spring blade cantilevered from the casing to trip the circuit breaker, Fig. 4, not shown.