operative cleaning position when they have moved out of the area occupied by the yarn attaching machine 11 i e when the roller 10 moves down the other ramp 12 39 by the action of said spring in the embodiment shown in the top half of fig1 instead of the flexible hose sections the air connections 14 15 are in the form of telescopic ducts to whose forward ends the vertically extending hoses 6 39 7 39 are connected these telescopic ducts are extended when the roller 10 comes into contact with the rail 12 the mode of operation of this embodiment is identical to that of the embodiment shown in the bottom half of fig1 the cleaning device and the yarn attaching machine may move towards one another during operation or the cleaning device may overtake the yarn attaching machine because normally the speed of motion of the cleaning device is three times that of said machine in the embodiment shown in fig2 the supporting and fixing device 8 39 of respective hoses 6 7 is attached to one end of an arm 16 forming part of a triangular linkage 16 20 the arm 16 is pivotally mounted at 17 to the blower housing 1 and filter casing 2 the other end of the arm 16 is articulated through a joint 18 to an arm 20 which is in turn articulated through a joint 19 to a threaded spindle 21 the spindle 21 is moved by a rotating spindle nut 23 the nut 23 being powered.