PURPOSE: To prevent a spring as a returning means, a rod, a control body, etc., from being damaged even when an operating piece collides with a door by mounting the spring to a connecting-supporting body, a support plate to the operating piece, and the control body to the rod respectively.

CONSTITUTION: When an operating piece 4 is subjected to an external force to turn in a horizontal plane, a rod 21 is pressed into the connecting--supporting body 7 side through a support plate 23 mounted to the operating piece 4. With the movement of the rod 21, a second switch 8 outputs a reversing operation command to an electric motor by operating a control body 27 to compress a spring 22 mounted to the connecting-supporting body 7. Further, when the external force is released, the operating piece 4 is returned from a position to which it has turned to the original position since the support plate 23 is subjected to pressing force provided through the rod 21. Namely, since the operating piece 4 is not provided with the spring 22 as a turning means, the rod 21 and the control body 27, the spring 22, the rod 21, the control body 27 are not damaged even when the operating piece 4 collides with a door.