Method for production of a yarn by the assembly of several basic yarns subjected to a prior transformation and device for carrying out the same

A method for producing a hybrid yarn, resulting from assembly by twisting, cabling or covering of a plurality of basic yarns, comprising:

• subjecting at least one yarn of a plurality of basic yarns to a prior transformation:
• at least one yarn of the plurality of basic yarns having a low elongation capacity under load, and at least one other yarn of the plurality of basic yarns having a higher elasticity and/or elongation capacity under load, the plurality of basic yarns being twisted separately to the different torsions, then assembled under equal or different tensions, and twisted together;
• a first transformation of the basic yarns is carried out in parallel in same machine by independent transformation means equipped with control means and being individually adjustable;
• carrying out on feeding devices a reduction in tension of each yarn of the basic yarns at an assembly point relative to an amount of tension resulting from the first transformation;
• the yarns are routed by guide means to the assembly point where the yarns are assembled and arranged in parallel;
• a bobbin receiving the assembled yarns in a device having, or being associated with, positive feeding means, operating without slippage with respect to the yarn, and configured to control speed of movement of the assembled yarns;
• placing the bobbin with assembled yarns in a spindle of a two-for-one twisting machine, the assembled yarns being joined together by twisting on themselves.

A method for producing a hybrid yarn, resulting from assembly by twisting, cabling or covering of a plurality of basic yarns, comprising:

• subjecting at least one yarn of a plurality of basic yarns to a prior transformation;
• at least one of the basic yarns having a low elongation capacity under load, and at least one other yarn of the plurality of basic yarns having a higher elasticity and/or elongation capacity under load, the plurality of basic yarns being twisted separately to different plies, then assembled under equal or different tensions, and twisted together;
• a first transformation of all or part of the plurality of basic yarns is carried out in parallel in same machine by independent transformation means equipped with control means and being individually adjustable;
• carrying out on feeding devices a reduction in tension of each yarn of the plurality of basic yarns at an assembly point relative to an amount of tension resulting from the first transformation, is carried out the feeding devices equipped with adjusting means and control systems adjustable individually so that the tension at the assembly point is adjusted individually;
• the yarns are routed by guide means to the assembly point where they are assembled and arranged in parallel;
• a bobbin receiving the assembled yarns in a device having, or being associated with, positive feeding means, operating without slippage with respect to the yarn, and able to control speed of movement of the assembled yarns;
• lacing the bobbin with the assembled yarns on a hollow twisting or covering spindle, in which the assembled yarns are joined by combining them with another yarn, by a direct cabling or covering method.

A device for preparing assemblies for producing a yarn resulting from assembly of a plurality of basic yarns in textile machines for transforming said yarns, comprising:

• upstream treatment or transformation units;
• first yarn feeding and advance means each controlled by an individual motor;
• feeding and spooling means having a thread guide;
• and
• assembly means for producing an assembly of several yarns, mounted in combination with several of the first yarn feeding and advance means, said assembly means, being placed between said first feeding means, and one of the feeding and spooling means being able to control speed of travel of the assembly of yarns, each individual motor, being subjected to a speed variator.