Defective weft yarn insertion prevention
AssigneePicanol N.V.
InventorJo Tacq
Life of this patent
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Abstract
A feed mechanism for several weft yarns, each with its own feed device capable of selecting the weft yarn to be inserted, includes sensors for monitoring the weft yarns for quality defects and for, upon detection a defect in a weft yarn, precluding the weft yarn from being selected for insertion until the portion of the weft yarn with the defect has been shunted into a region from where it can no longer be woven into the fabric.
Claims18
A method of controlling a weft yarn feeding mechanism, the feed mechanism including a control unit;
- means for alternately feeding at least two weft yarns, each weft yarn being fed by its own feed device, with each feed device including a yarn supply;
- and means for selecting a weft yarn to be inserted into a weaving shed to form a fabric, comprising the steps of:
- monitoring the weft yarns for quality defects in the region between the yarn supplies and the fabric;
- generating a defect-indicating signal based on said monitoring when a defect is detected;
- transmitting the signal to said control unit;
- causing the selection means to exclude the weft yarn with the defect from its selection operation;
- and
- after detection of the defect, continuing to move the weft yarn containing the defect through said selection means until the defect has reached a predetermined position downstream of said selection means at which insertion of a non-defective portion of the weft yarn containing the defect will not cause the defect to be inserted within the shed.
A weft yarn feeding mechanism for alternately supplying at least two weft yarns to be inserted into a weaving shed to form a fabric, each weft yarn being fed by its own feed device and each feed device comprising a yarn supply, and means for selecting a weft yarn to be inserted into the fabric, comprising:
- means including at least one detector for each feed device for monitoring a respective weft yarn for quality defects, and generating a defect signal based thereon, said detector being mounted between the yarn supply and the fabric and connected to a control unit, the control unit including means for receiving the defect signal;
- and means for preventing the selection means from selecting a weft yarn for weft insertion until a portion of the weft yarn which includes a defect has been shunted through the selection means into a predetermined region downstream of the selection means from where the defect will not be inserted into the shed when a non-defective portion of the weft yarn containing the defect is inserted into the fabric.
Dependencies are inferred from the claim text.