Adjustable magnetic trip unit and a circuit breaker incorporating the same
AssigneeEaton Corporation
InventorsFarhad Afshari, Arthur D. Carothers
Life of this patent
Estimating the term…
Abstract
The magnetic trip device of a circuit breaker has a magnetic pole in which a magnetic field is generated by load current, and an armature assembly that includes: a bracket supported for pivotal movement relative to the magnetic pole; a spring biasing the bracket to a position spaced from the magnetic pole; an armature hinged on the bracket; and an adjusting screw for adjusting a gap between the armature and the magnetic pole for calibrating the trip device without affecting the spring bias, which can be separately and independently adjusted to select the load current at which the magnetic trip is initiated.
Claims16
An adjustable magnetic trip device for interrupting load current through a circuit breaker, the trip device comprising:
- a magnetic pole in which a magnetic field is generated by the load current;
- and
- an armature assembly comprising:
- a bracket supported for movement toward and away from the magnetic pole;
- a spring biasing the bracket to a position spaced from the magnetic pole;
- an armature;
- and
- a mount selectively positioning the armature on the bracket to adjust a gap between the armature and the magnetic pole.
A circuit breaker comprising:
- a housing;
- separable contacts within the housing;
- a line conductor and a load conductor connected through the separable contacts;
- an operating mechanism within the housing operable to open the separable contacts when actuated;
- and
- an adjustable magnetic trip device within the housing actuating the operating mechanism and comprising:
- a magnetic pole adjacent the load conductor and in which a magnetic field is generated by load current passing through the load conductor;
- a bracket mounted for pivotal movement toward and away from the magnetic pole;
- a spring biasing the bracket to a position spaced from the magnetic pole;
- an armature;
- and
- a mount selectively positioning the armature on the bracket to adjust a gap between the armature and the magnetic pole without affecting the spring biased position of the bracket.
Dependencies are inferred from the claim text.