Patent ID: 8497750

Claim:
A release mechanism for a circuit interrupting device, the release mechanism comprising: a ferromagnetic main frame through which a current can flow; and a ferromagnetic movable core configured to be translated in an opening of the main frame between a first position in which the circuit interrupting device remains closed and a second position in which the circuit interrupting device is opened, the release mechanism being configured to use flux generated inside the main frame by the current flowing through the main frame to displace the movable core between the first position and the second position; and at least two permanent magnets mounted on the main frame on each side of the opening and relatively oriented so as to generate a unidirectional unique magnet flux inside the main frame and the movable core, the magnet flux creating a first force on the movable core that maintains the movable core in the first position, wherein a first current is defined as a current flowing through the main frame and generating a first flux inside the main frame and the movable core in the same direction as the magnetic flux, a predetermined first limit value is defined in connection with the first current, a second current is defined as a current flowing through the main frame and generating a second flux inside the main frame and the movable core in the direction opposite to the magnetic flux, a predetermined second limit value is defined in connection with the second current, the permanent magnets, the movable core and the main frame are configured so that the movable core is displaced from the first position into the second position when the first current exceeds the predetermined first limit value, or when a second current exceeds the predetermined second limit value, and wherein the second limit value is different than the first limit value.