| 摘要 |
A circuit breaker comprising a solenoid coil, an armature actuatable by the coil and a magnetizable frame carrying the coil enclosed with a case comprising two abutting half-cases. A time delay device comprising a tube of non-magnetic material within which is a movable magnetizable core and with which the coil cooperates to actuate the armature after a time delay period upon predetermined energization of the coil. The tube has a pole piece at one end and the armature has an attractable portion which moves toward said pole piece on predetermined overload conditions, the core being biased toward the end of the tube away from the pole piece. An adjustable cam is carried between said half-cases. Said attractable portion of the armature being biased by a spring into engagement with said cam and away from said pole piece. Said cam being rotatable to vary the air gap between said pole piece and said attractable portion of the armature, whereby the trip point of the circuit breaker may be varied. |
