PURPOSE: To simplify the constitution of a device sharply without losing the reliability of its operation by providing the device with a small gear to be rotated by a motor and a large gear enabled to the engaged with the small gear and having a teeth-lost part on a part.

CONSTITUTION: The small gear 13 is fitted to the rotary shaft of a motor when a direct driving type motor is used for instance, and when a normal motor is used, fitted to the rotary shaft of a turntable. The small gear 13 is arranged so as to be opposed to the teeth-lost part 12 and is provided with a pawl 14 to be rotated unitedly with the small gear 13. The large gear 9 is fitted freely rotatavely to the shaft 11 implanted on the lower surface of a fixing board 10. Althrough teeth are arranged on the periphery of the large gear 9, a part of the teeth is cut to form the teeth-lost part 12. Thus, the constitution can be sharply simplified without losing the reliability of the operation.