| 摘要 |
PURPOSE:To prevent an unstable state from being produced at switching even when a motor is reversed by bringing a switch drive member into slide contact with a cam member, and causing the switch drive member to interlock with the cam member through a drive body fixed in the rotating direction of a motor and movable in a reversing direction. CONSTITUTION:When a motor is rotated, a cam member 28 and a profile cam 32 are rotated and a D-shaped protrusion 33 also is rotated to open and close a damper. In which case, a stop in an opening and a closing position is needed, through displacement of the outer size of the profile cam 32, a switch drive member 34 to hold a permanent magnet 36 is moved, and a switch 37 is turned ON and OFF. When the switch 37 is turned OFF, the switch drive member 34 is stopped at a slope 32b. In which case, when reversing is effected during restarting, the cam member 28 is also reversed, a drive body 39 is energized in a direction in which it ascends the slope 32b but since resistance is high, the shaft part of the switch drive body 34 is moved in the direction of a shaft hole against the force of a leaf spring 40b. Thereby, the position of the permanent magnet 36 is not changed, and the switch 37 is prevented from unstable operation. |
