Tension setting and controlling method and apparatus in an automatic winder

In an automatic winder provided with a plurality of winding units, each winding unit having a tension device and a yarn joining device for joining together a yarn extending from a feed bobbin and a yarn extending from a package, a method of controlling yarn tension comprising the steps of:

• joining yarns with the yarn joining device;
• applying tension, which is greater than that normally applied by the tension device but smaller than that applied in a test of yarn strength, to the joined yarn after the step of joining by the joining device;
• detecting whether a yarn breakage occurs following the step of applying tension;
• repeating the steps of joining, applying and detecting upon the detection of a yarn breakage;
• detecting the frequency of detected yarn breakages;
• and
• comparing the detected frequency with a preset value, wherein upon the detected frequency exceeding the preset value, a judgment is made that the joining device is abnormal.

A method for inspecting a yarn joining device operable for joining together a yarn on the side of a feed bobbin and a yarn on the side of a package, and operable with a tension device for controlling tension of a yarn wound on the package from the feed bobbin, the method comprising the steps of:

• joining yarns with the yarn joining device;
• applying tension, which is greater than that normally applied by the tension device but smaller than that applied in a test of yarn strength, to the joined yarn after the step of joining by the joining device;
• detecting a yarn breakage occurring following the step of applying tension;
• repeating the steps of joining, applying and detecting upon the detection of a yarn breakage;
• detecting the frequency of detected yarn breakages;
• and
• comparing the detected frequency with a preset value, wherein upon the detected frequency exceeding the preset value, a judgment is made that the joining device is abnormal.

In a yarn winding apparatus operatively controlled by a control device and having a yarn tension detector to detect yarn winding tension, as wound yarn detector for detecting the amount of yarn wound and a yarn tension adjuster to adjust yarn winding tension, a method of controlling yarn tension comprising the steps of:

• determining a functional relationship between yarn tension and amount of yarn wound;
• detecting the amount of yarn wound;
• determining the yarn tension value which is functionally related, according to the determined functional relationship, to the detected amount of yarn wound;
• and
• adjusting the yarn winding tension with the yarn tension adjuster toward the determined tension value.

In a yarn winding apparatus having an adjustable yarn tenser operable in a predefined yarn tension range, and also having a yarn winding speed controller, a method of controlling yarn winding tension comprising the steps of:

• sensing the yarn winding tension;
• adjusting the yarn winding tension with the adjustable yarn tenser upon the yarn winding tension being within the predefined tension range;
• and
• adjusting the winding speed with the winding speed controller upon the yarn winding tension exceeding the predefined range.

In a yarn winding apparatus operatively controlled by a control device and having a yarn tension detector to detect yarn winding tension and a yarn tension adjuster to adjust yarn winding tension, a method of controlling yarn tension comprising the steps of:

• inputting data to the control device, the input data corresponding to at least one of the kind of yarn processed with the yarn winding apparatus, the thickness of the yarn processed with the yarn winding apparatus, and the standard winding speed of the yarn winding apparatus;
• determining a tension value based on the data input to the control device;
• and
• adjusting the yarn winding tension with the yarn tension adjuster toward the tension value determined by the control device.

A yarn winding apparatus having an adjustable yarn tenser for adjusting the yarn winding tension for winding yarn about a yarn package, the apparatus comprising:

• input means operable for receiving data corresponding to at least one dimension of the yarn package;
• calculating means operatively connected with the input means, for determining a functional relationship between yarn tension and amount of yarn wound, the functional relationship being dependent on data received by the input means;
• detecting means for detecting the amount of yarn wound about the yarn package;
• and
• control means, operatively connected with the calculating means, the detecting means and the adjustable yarn tenser, for controlling the adjustable yarn tensor to adjust the yarn winding tension toward the tension, which is functionally related, according to the functional relationship determined by the calculating means, to a detected amount of yarn wound.

A yarn winding apparatus for winding yarn at an adjustable winding speed and winding tension, the apparatus comprising:

• a yarn tension sensor;
• an adjustable yarn tenser operable in a predefined winding tension range;
• a winding speed adjuster;
• control means, operatively connected with the yarn tension sensor, the winding speed adjuster and the adjustable yarn tenser, for operating the adjustable yarn tenser to control the winding tension when the winding tension is within the predefined tension range and for operating the winding speed adjuster to control the winding tension when the winding tension exceeds the predefined tension range.