PURPOSE: To utilize the rotating force of a driving motor as operating sources of various control elements by interposing a clutch mechanism which is opened when a magnetic tape is drawn out and in operation when not between a rotating force leading-out mechanism and a movable member.

CONSTITUTION: A couple of left and right sliders 30a and 30b are provided facing the revolving shaft of a rotating drum 4, i.e. a pinion 19 as the rotating force leading-out mechanism, and the clutch mechanism 35 is interposed between the pinion 19 and sliders 30a and 30b. This clutch mechanism 35 consists of an oscillatory member 36 and a loading driving source for rotating the pinion 19a the pinion 19 meshes a sector gear 36a during unloading to utilize the rotating force of the rotating drum 4 as the operating sources of control elements, and is released to mesh the sector gear 36a during loading.