Patent ID: 8373523

Claim:
An electromagnetic trip device for a circuit breaker, comprising: a current path including a conductor guiding an electric current through at least one contact point formed between a fixed contact piece and a movable contact piece; a movable contact lever carrying the at least one movable contact piece, the contact lever being mounted to be movable between a closed contact position and an open contact position; and a magnetic circuit including an air-gap in which the movable contact lever is at least partially located, wherein the electric current flows through the contact lever, the current path extending through the air gap, so that a magnetic field generated by the current flowing through the contact lever directly interacts with a magnetic field within the air-gap to generate a Lorentz-type repelling force on the contact lever, and wherein a central portion of the contact lever is configured to be a thin but high metal sheet, which is configured to glide in the air gap with its broad sides in a parallel manner adjacent to side walls of the air gap.