the fiber material since the direct cumulative angle of rotation of the two motor drive shafts are a measure of the unit quantities of the transported fiber material fm then by means of the counter z the quantity of delivered fiber material and the quantity of removed fiber material is continually enumerated thereby the difference between delivered and removed fiber material can be continuously determined this quantity based on a starting quantity represents the content in storage dependent upon this value the rotational speed of the drive means for the low dynamic operational component ao 1 is accordingly adjusted the rotational speed for the high dynamic operating component is not adjusted the quantity of delivered fiber material fm is determined by counting signals from the signal generator t 1 that is connected to the drive shaft of a motor m 1 this motor m 1 drives the operational component ao 1 which delivers the fiber material fm to the storage s on the exit of the storage s the fiber band is transported by a high dynamic drive system ab 2 the drive means in the system are made up of a motor m 2 a signal generator t 2 which is placed on the drive shaft of the motor.