Patent attributes
A one-way rotational transfer mechanism includes a rotary input shaft; a hollow-cylindrical rotary output shaft positioned around the rotary input shaft; a circumferentially-uneven-width-space forming portion formed on the rotary input shaft to form at least one accommodation space between the rotary input shaft and the cylindrical inner peripheral surface; a movable member; balls positioned between first and second holding surfaces; at least one roller member installed in the accommodation space; and a biasing device which biases the movable member so that the balls are sandwiched between the first and second holding surfaces and so that an normal surface and the roller member come into pressing contact with each other. The circumferentially-uneven-width-space forming portion is shaped so that a rotation of the rotary input shaft is transferred to the hollow-cylindrical rotary output shaft via the roller member when the rotary input shaft is rotated.