position with respect to the mounting axis or the pressure roller furthermore it constitutes an inexpensive solution to the problem solved by the invention the controlled movement of the suction nozzle 7 or 41 from a lateral position to the central plane of the drafting arrangement is preferably carried out so fast that the yarn loop f is extended the length of the gap between cap 5 or 28 and the cover 4 this serves to aid in preventing the yarn section 6 from getting caught in this gap fig1 to 16 illustrate three further embodiments which show that the cap does not necessarily have to be provided on the axle of the pressure roller the corresponding components of the embodiment described with reference to fig5 to 10 have the same reference numerals as corresponding components in fig1 to 16 alternative components are exclusively limited to the cap and its carrier the attachment of the cap on the carrier is not made within the pressure roller but on a surface component of the cap which is not touched by the yarn during the depositing movement in the embodiments shown in fig1 and 12 cap 105 is carried by an arm 106 which is mounted on a service robot not shown see however ep 421 152 as an element of a handling device cap 105 can be delivered to pressure roller 3 during an operating process by means of.