Abstract: A low-voltage limiting circuit breaker comprises a stationary contact part and a movable contact part itself comprising a support pivoting around a fixed axis between a closed position and an open position, a contact finger pivoting around a fixed axis between a non-repelled position and a repelled position, and a bistable device comprising a spring arranged between the support and the finger. When the finger is positioned in its repelled position and the support pivots from its closed position to its open position, it drives the finger to its non-repelled position. A part of the energy necessary to pass the dead point of the bistable device is provided by a spring which urges the support to its open position only at the beginning of opening, which enables the opening spring of the circuit breaker not to be overdimensioned.

Abstract: A low-voltage multipole circuit breaker with high electrodynamic strength comprises a case made of insulating material, subdivided into a front compartment housing an operating mechanism commanding opening and closing of the circuit breaker and a rear compartment separated from the front compartment by an intermediate wall. The rear compartment is itself subdivided into individual compartments by separating partitions, each individual compartment housing one of the poles of the circuit breaker. The operating mechanism is linked to a pole shaft common to all the poles. The pole shaft is located in the rear compartment and supported by bearings passing through the separating partitions.