It has been often considered that known conventional fisherman's knots or weaver's knots are valuable as yarn splicing means suitable for mass production and it cannot be helped that yarn defects are caused by adoption of these yarn splicing methods.
Accordingly, in case of fisherman's knots or weaver's knots, improvement of the binding strength alone has been intended so that falling of yarns is not caused even if knots are pulled, but in connection with decrease of the thickness of the knot which is about 3 times the thickness of a single yarn, only reduction of the size of the yarn end projecting from the knot has been tried. However, this large thickness of the knot results in breakage of the yarn by a knitting needle at the knitting step and continuous operation of a knitting machine is inhibited. If a knitting machine is operated continuously irrespectively of occurrence of such breakage of yarns, a knitted fabric having defective holes is produced. Furthermore, in an air or water jet room, the yarn ends projecting from knots of wefts fall in contact with opened warps and there is caused a disadvantage that the wefts fail to reach the ends of a fabric being weaven. Moreover, knots appearing on a woven fabric as a final product are regarded as defects, and in order to obtain a high quality product, a region including such knots is excluded from the fabric and in case of a medium quality or lower quality product, there should be adopted a troublesome manual operation of pushing the knots to the backside of the fabric. Accordingly, if knots are sufficiently small but can resist pulling forces applied at various processing steps, the foregoing disadvantages involved in the manufacturing process and the product quality will be eliminated.
We previously filed some patent application for means for solving the foregoing basic problem. Also in the present invention, we propose a method and apparatus for solving this problem.
According to one of our previous proposals, a yarn on the package side and a yarn on the bobbin side, which are to be spliced together, are cut and yarn ends are held by a yarn cutting and holding device and the yarn ends are subjected to an action of a splicing nozzle. In this method, however, fibers of the yarn ends on both the sides of a formed knot are not wound on the yarn but left in the angular form, and there is caused a defect that two yarns are piled together in the spliced joint and the diameter of the spliced joint becomes larger than in other regions. The main problem of the present invention is how to eliminate this defect. Of course, the utility of our previous proposal is not denied at all by the present invention, but the basic problem in the manufacturing process has already been solved by our previous proposal through a product is still insufficient in the quality (the quality grade) to some extent. More specifically, when knots of our previous proposal are adopted for two doubled or twisted yarns, the above-mentioned defect concerning the quality is not conspicuous, but in case of the knitting process using cotton or wool or the weaving process where single yarns are often used for formation of knitted or woven fabrics, knots of our previous proposal tend to result in a defect of the quality. The present invention is to eliminate this disadvantage involved in our previous proposal.