Included are: a closing spring which provides a closing drive force for closing a contact of a switch device by rotating a camshaft by release of energy; a first semi-circular latch which retains stored energy of the closing spring via a closing lever; an output lever which pivots by being pressed by a cam provided on the camshaft when retention by the first semi-circular latch is released and the energy of the closing spring is released, and transmits the closing drive force to the switch device via a linking mechanism; and a second semi-circular latch which prevents the output lever from pivoting in a tripping direction via a tripping lever and retains stored energy of an interrupting spring provided on the linking mechanism, the pivoting of the output lever being caused by transmission of the stored energy of the interrupting spring.