Device for automatically winding up the initial reserve yarn quantity on the end of a small tubular element of a bobbin in the textile industry

Claim 1

Apparatus for forming an initial quantity of reserve yarn in the form of a single helically wound layer at one end of a bobbin, comprising a yarn slide bar parallel to the bobbin and having a first groove therein, a rotatable shaft parallel to and disposed between the yarn slide bar and the bobbin, a drum mounted nonrotatably on said shaft and having a helical peripheral groove thereon and a tapered surface on the same side of the drum as the midplane of the bobbin, said first groove lying substantially in a plane perpendicular to the axis of said shaft and disposed midway between the ends of said helical groove, and a yarn guide that reciprocates parallel to the bobbin along a path disposed between the bobbin and the rotatable shaft, whereby the yarn passing on one side of said slide bar through said first groove passes on the opposite side of said drum through said helical groove and thence to the bobbin, and traverses upon rotation of said helical groove to form said initial quantity of reserve yarn while remaining in said first groove, and then leaves said first groove when urged laterally by said tapered surface and enters said yarn guide.