Abstract: A printing apparatus including a plurality of movable flexible endless belts incorporated in a plate drum which are aligned side by side, each of the endless belts being provided with spaced printing type on its outer peripheral surface and arranged side by side in at least on row within the plate drum. The endless belt has power transmitting means including an electromagnetic clutch which is coupled to a slip ring segment for feeding current to the clutch. A plurality of slip ring segments are arranged on substantially concentric circular lines. Every time each of the belts is displaced by a distance corresponding to one spacing between adjacent type, the displacement is detected as an electric pulse by a detecting means. A selected type can be brought to a specified position by the use of means for selectively determining the duration of energization of the electromagnetic clutch based on the detection effected as above.