PURPOSE: To house and arrange a gear system in a small space, by arranging a driving gear, a first notch gear, and a second notch gear respectively so as to enclose the periphery of an intermediate gear.

CONSTITUTION: Since the driving gear 46, the first notch gear 38, and the second notch gear 39 are arranged so as to enclose the periphery of the intermediate gear 45, both notch gears 38 and 39 with different function are driven rotatably respectively by one intermediate gear 45 being always driven rotatably by the driving gear 46. And the driving gear 46 is also the gear to transfer a driving force to a pair of reel bases. In such way, it is possible to house and arrange the driving gear for driving the reel base required for a tape recorder, the first notch gear 38 for switching the reproducing (recording) mode, and the second notch gear 39 for switching a tape feeding direction, in the small space centering the intermediate gear 45.