transport from the groove feeler roll pair 3 to the draw frame which comprises the entry mid and delivery roll pairs 20 21 22 a dead time is computed that corresponds to the time delay in the fifo memory the theoretically computed dead time is continually corrected with consideration given to the dynamic drive of the regulation motor 11 and the drive line belonging thereto the speed of rotation for the regulation motor 11 as a control value is determined by the control and or regulation unit 10 which processes the actual band thickness of the fiber band the set value of the band thickness as a guide size and the speeds of rotation of the main motor 8 and the regulator motor 11 by means of the proportional superimposition of the speed of rotation of the main motor 8 and the regulation motor 11 and taking into consideration the computed dead time the band thickness is regulated in the draw frame at the regulation application point which lies between the middle roll pair 21 and the delivery roll pair 22 a component in accord with the invention of the regulated draw frame which has been presented as an example is at least one very precisely measuring band thickness sensor 30 at the delivery end of the draw frame which in the shown embodiment fig1 follows a band funnel 19 the sensor 30 of this embodiment for example can very exactly measure the band thickness variations which is also the band weight variations of the regulated or processed fiber band 2 u2032 leaving the machine by means of microwaves other principles of measurement with.