the mouth 9 of said tube 3 the kinematically firm attachment of the spinning in head 1 in the plane of motion of the swing lever 5 is advantageous in that the axis of the yarn introducing element is permanently kept parallel to the axis of take off tube 3 according to one of the exemplary embodiments as shown in fig3 the attaching means is at least one leaf spring 10 whose surface in the spinning in position of the spinning in head 1 is parallel to the axis of take off tube 3 it however is more preferable to use of pair of such springs 10 as shown in fig3 according to another embodiment fig5 the attaching means is a compensating pivot 11 which is attached to the swing lever 5 with elastic members 12 the compensating pivot 11 is mounted for free reciprocation through the spinning in head 1 so as to be in the yarn introducing position parallel to the take off tube 3 and to allows motion in the direction of arrows according to the embodiment shown in fig4 and 6 the preferable kinematically firm guiding of the spinning in head 1 in the plane of its movement but with a swing motion across the mouth 9 of the take of tube 3 is achieved by attaching means consisting on the one hand of a fixed pivot 13 provided on the swing lever 5 and allowed to pass freely through holes 14 in in two spaced apart guide walls 15 and 16 of the spinning in head 1 and on.