PURPOSE: To prevent malfunctions caused by impacts, by providing another armature lever for preventing malfunctions, which prevents an original armature lever for actuating members from moving rotationally by the impacts, in addition to the original armature lever for actuating members.

CONSTITUTION: Two armature levers 3a, 3b are so provided as to make a nearly right angle with each other at their static positions. That is, the armature lever 3b is hard to move against an impact in a direction V, and is easy to move against an impact in a direction H. On the other hand, the armature lever 3a is easy to move against the impact in the direction V, and is hard to move against the impact in the direction H. Therefore, either armature lever 3a or 3b is resistant to the impact in the direction V or H. For this reason, one of the armature levers can be used as an original armature lever, i.e., as the armature lever 3a for actuating members, and the other one can be used as the armature lever 3b for stopping, which prevents the armature lever 3a for actuating members from malfunctioning. Thereby, the malfunctions caused by the impacts can be prevented.