PURPOSE: To enable smooth acceleration of a doffer, by linking a cylinder- driving system to a doffer-driving system via a clutch in the start-up of a carding engine, releasing the clutch when the revolution of the doffer reaches a preset low rate of revolution and driving the doffer at a high rate of revolution.

CONSTITUTION: In the start-up of a carding engine, a doffer 10 is driven by the combination of a doffer-driving variable speed motor M2 and a cylinder- driving main motor D1 keeping a clutch MC in connected state until the doffer reaches a predetermined low rate of revolution. The cylinder 1 and the doffer 10 are driven surely synchronized manner. When the doffer 10 reaches a predetermined low rate of revolution, the clutch is released and the rotation of the motor M2 is accelerated to smoothly transfer the doffer 10 to a high-speed revolution without causing the drop of the rotational speed.