drafted slivers are introduced at the outlet of the draw unit into a sliver guide 44 and are by means of calender rolls 45 and 46 pulled through a sliver trumpet 47 in which the slivers are combined into a single sliver 48 which is subsequently deposited into a non illustrated coiler can the calender rolls 37 38 the lower input roll iii and the lower mid roll ii which are mechanically coupled to one another for example by means of a tooth belt are driven by a regulating motor 49 as a function of an inputted nominal desired value the upper rolls 40 and 41 are driven by friction from the respective lower rolls the lower output roll i and the calender rolls 45 46 are driven by a principal motor so the regulating motor 49 and the principal motor 50 have a respective regulator 51 and 52 the rpm regulation is effected by a closed regulating circuit in which the regulator 51 is connected with a tachogenerator 53 and the principal motor 50 is connected with a tachogenerator 54 at the inlet of the draw unit a mass proportionate magnitude for example the cross section of the slivers 35 is sensed by the measuring organ 39 at the outlet of.