Abstract: The yarn manufacturing process is monitored by detecting a yarn tension while the yarn spun by a spinning device is wound by a winding device. The yarn tension detected by the yarn tension sensor is corrected based on the rate of change in a winding condition such as a traverse speed or a winding speed, and whether the yarn manufacturing process is in a normal condition or not is judged based on the corrected tension. Also, an abnormal judging reference is corrected based on the rate of change in a winding condition, and whether the yarn manufacturing process is in a normal condition or not is judged based on the corrected abnormal judging reference.

Abstract: An apparatus, for measuring a yarn tension, capable of preventing a filament breakage or loop from being generated while eliminating the necessity of adjustment and keeping a desired precision of measurement. The apparatus is constructed by an unit 1 for an application of a vibration to a yarn being moved, an unit 2 for measuring an apparent transverse wave propagation velocity of the yarn, and a unit 3 for calculating a true transverse wave propagation velocity based on the yarn speed and the calculated apparent transverse wave propagation velocity of the yarn. A control of a winding of the yarn in accordance with a propagation velocity of the transverse wave is also disclosed.

Abstract: To equalize yarn tensions in a normal winding mode and a yarn switching mode when a yarn take-up operation is carried out by a yarn winder, the surface speed of the contact roller 4 or the frequency of current for driving the contact roller-driving motor 7 is controlled in a programmed manner. The programmed control is based on whether the winder is in the normal winding mode, the yarn switching mode in which the yarn is switched from a full bobbin to an empty bobbin, or a soft-touch winding mode in which the contact roller is brought into soft contact with the empty bobbin.

Abstract: An apparatus for winding a plurality of yarns comprises:a pair of spindle frames independently and horizontally movable along parallel passages;each of the spindle frames having a plurality of rotatable spindles horizontally projecting therefrom, which are vertically superposed and which are axially displaced by a predetermined length from the top spindle to the bottom spindle;a threading arm frame disposed at the center of the spindle frames and having threading arms pivotally mounted thereon, the number of the threading arms being the same as that of the spindles mounted on each spindle frame, and the threading arms are axially displaced by the predetermined length from the top arm to the bottom arm; andinduction motors connected to the rotatable spindles, respectively.