with the thread guide yoke 7 and is mounted on the mounting 22 as is a leaf spring 81 which acts as a thread clamp 8 the restraining spring 71 which is primarily to prevent the piecing thread from sliding away on the thread guide yoke extends from its attachment point in the direction of the thread guide yoke 7 and crosses the latter the production of wrap yarn takes place as follows the binding thread b thread path b 39 running off from the binding thread bobbin 4 and the spinning fiber bundle emerging from the delivery roll pair of the drafting apparatus pass through the rotating hollow spindle the binding thread b being laid helically about the spinning fiber bundle s the spinning fiber bundle s emerging from the pair of delivery rolls can therewith remain untwisted or acquire a false twist in that it is brought for example into frictional contact with the hollow spindle 3 the wrap yarn produced is drawn off from the hollow spindle 3 by the takeoff roll pair 5 50 and is wound up into the yarn bobbin sp if the spinning fiber bundle s breaks because of a disturbance only the binding thread b is drawn out of the hollow spindle 3 the driving connection of the tangential belt 31 with the hollow spindle 3 is interrupted and the latter is braked to a standstill the spinning fiber bundle s still continuously emerging from the delivery roll pair 1 2 of the drafting apparatus is seized by the suction air stream flowing in the suction tube 11 and is sucked away in order to prevent further drawing of the binding thread b out of the hollow.