Abstract: A device for mechanically changing over the direction of transmission of turning force in which engaging elements are mounted between its driving member and driven member. It prevents the generation of abnormal noise resulting from the repeated engagement and disengagement of engaging elements when turning force is applied from the driven member. Sprags and sprag-supporting retainers are provided between an outer ring as driven member and an inner member as driving member. Also an elastic member is mounted between the outer ring and the inner member. When turning force is transmitted from the outer ring to the inner member, the inner member and one of the retainers begin rotating first, biased by the elastic member. The retainers thus rotate relative to each other, inclining the sprags in the same direction as the inner member to a ready-to-engage position. The sprags are thus prevented from repeatedly engaging and disengaging, so that there will be no abnormal noise.