PURPOSE: To efficiently move an actuating member by simple constitution by providing a means for separating an actuating means from operating assotiation with a driving means in response to the arrival of the actuating means to a given position.

CONSTITUTION: An actuating lever 1 has a hole part 1a therein a guide bar 2 passes, and a semicircular female part 1b. Rotating a motor 4 in one direction rotates a drive shaft 3, in coaxial with a motor shaft to be retained by bearing plates 5 and 6, in the same direction with the motor 4. Rotating the drive shaft 3 moves the actuating lever 1 according to a guide bar 2 in parallel to the drive shaft 3 because of the engagement between the male screw part of the drive shaft 3 and the female part 1b of the actuating lever 1. A cam pin 1c is in the lower side of the actuating lever, and comes contact with the cam surface of the cam part 7a of a bottom board 7 to ensure the engagement between the female screw part 1b of the actuating lever 1 and the drive shaft 3. The continuous rotation of the motor 4 gradually moves it in an A direction to near a corner part 7e where the cam part 7a disappears.