Energy absorbing contact arm stop

A circuit breaker comprising:

• a housing;
• a cassette disposed within said housing, said cassette includes an inner surface;
• at least two fixed contacts disposed within said cassette;
• a rotar movable contact assembly disposed within said cassette, said movable contact assembly comprising at least two movable contacts on a contact arm, said contact arm being positionable in a closed position and a blown open position, wherein said contact arm is closed when said at least two movable contacts are in contact with said at least two fixed contacts and said contact arm is blown open when said at least two movable contacts are repelled away from said at least two fixed contacts in response to a short circuit condition;
• said movable contact assembly further comprising at least one contact spring, said at least one contact spring having an orientation that exerts a closing bias torque on said contact arm relative to said at least two fixed contacts when said contact arm is closed, said closing bias torque not increasing from a closed position to a blown open position of said movable contact arm;
• and
• at least one kinetic energy-absorbing stop disposed proximate to said inner surface, wherein a surface of said contact arm, said inner surface, and a surface of said at least one kinetic energy-absorbing stop are generally parallel to each other when said contact arm is in said blown open position,
• wherein said at least one kinetic energy-absorbing stop absorbs and dissipates the kinetic energy resulting from magnetic repulsive forces forcing said at least two movable contacts and said at least two fixed contacts apart during a short circuit condition so that said contact arm does not rebound to the closed position.

A circuit breaker comprising:

• a housing;
• a cassette disposed within said housing, said cassette includes an inner surface;
• a first fixed contact disposed within said cassette;
• a second fixed contact disposed within said cassette;
• a movable contact assembly disposed within said cassette, said movable contact assembly comprising;
• at least two movable contacts on a contact arm, at least one contact springs that positions at least one spring support member and exerts a closing bias torque on said contact arm when said contact arms is closed, said closing bias torque acting through said spring support member not increasing from a closed position to a blown open position of said contact arm;
• wherein said contact arms is positionable in a closed position and a blown open position, wherein said contact arms is closed when said at least two movable contacts are in contact with said first and second fixed contacts and said contact arm is blown open when said at least two movable contacts are repelled away from said first and second fixed contacts in response to a short circuit condition;
• a first kinetic energy-absorbing stop disposed proximate to a first recess of said inner surface of said cassette, wherein a first surface of said contact arm, said first recess of said inner surface, and a surface of said first kinetic energy-absorbing stop are generally parallel to each other when said contact arm is in said blown open position;
• and
• a second kinetic energy-absorbing stop disposed proximate to a second recess of said inner surface of said cassette, wherein a second surface of said contact arm, said second recess of said inner surface, and a surface of said second kinetic energy-absorbing stop are generally parallel to each other when said contact arm is in said blown open position;
• wherein said first and second kinetic energy-absorbing stops absorb and dissipate the kinetic energies resulting from magnetic repulsive forces forcing said at least two movable contacts and said first and second fixed contacts apart during a short circuit condition so that said contact arms does not rebound to the closed position.