<p>Disclosed is a device which is equipped with a rotary body (M) so combined with a support body as to be capable of rotating at least between a reference position and an extended position and which is so constituted that the rotary body or the support body is used at the extended position. A biasing force acts on the rotary body at the extended position in the direction, in which the rotary body is rotationally returned to the reference position. The device is further equipped with a speed changeover means for differentiating the rotation speed of the rotary body from the extended position to a predetermined intermediate position during the returning rotation from the rotation speed thereof from the predetermined intermediate position to the reference position.</p>
