Power take-off device of a mobile working machine

The device (2) has an electronic control unit (14) for actuating a power take-off shaft clutch (12) arranged between a transmission (6) and a power take-off shaft (10). The control unit is provided with a flange-mounting function unit which, when activated, executes a rotary position correction of the power take-off shaft. The flange-mounting function unit causes minimal rotation of the power take-off shaft with a torque greatly restricted with respect to nominal torque of the secondary drive device. An independent claim is also included for a method for coupling and/or uncoupling a working machine to/from a secondary drive device of a mobile working appliance as an energy source.