The present invention relates to a yarn carrier, and a method and apparatus for manufacturing the same, and wherein the carrier is characterized by the ability to accommodate the tail of the yarn to be wound thereon between the carrier and the base plate of the winding machine, without severing the yarn tail during winding of the package.
Yarn carriers of the described type are designed to be wound with a yarn, and with a yarn tail extending from the carrier to permit the trailing end of the yarn on an exhausted carrier to be tied to the leading end of the yarn on a succeeding fully wound carrier. The yarn tail is typically formed at the beginning of the yarn winding operation by taking a length of yarn and extending it over the open large end of the carrier. The carrier is then mounted into a cradle of the winding machine which includes a base plate which fits into the large end of the cone and holds the yarn tail. A nose plate secures the small end of the carrier for proper rotation about a fixed axis in the machine, and the carrier is rotated by a rotating drum which engages the surface of the carrier and which feeds the yarn onto the rotating carrier in a predetermined reciprocating pattern.
Such yarn carriers are commonly manufactured from a sheet of paper which is wound about a mandrel to form a frusto-conical tubular member composed of several layers of the paper sheet. Both ends of the resulting tubular member are trimmed during the winding operation to provide even end surfaces, and the carrier is then finished to provide a rounded nose at the small end. The above end trimming operation is conventionally effected by a knife blade which moves radially inwardly against the paper sheet as it is being wound, and this operation inherently produces a rather sharp, annular burr at the intersection of the inner wall surface and the cut end surface at the large end of the tubular member. The annular burr at the large end is undesirable, in that it acts to sever the yarn tail when the yarn tail is positioned between the large end of the carrier and the base plate of a winding machine in accordance with the above described winding procedure. More particularly, the carrier often rotates relative to the base plate during the starting and stopping of the winding operation, and this relative movement causes the annular burr to sever the yarn tail.
To alleviate the severance problem, it has been proposed to polish the inside wall at the large end of the tubular member, to eliminate the burr. More particularly, this prior polishing operation has been performed with the use of a chuck having a profile matching the desired profile of the large end of the carrier, and it resulted in a slightly beveled edge on the inside of the large end of the carrier, and with the paper material at the large end being compressed to form a relatively hard inner surface.
While the polishing of the inner end of the carrier has been a generally satisfactory method of removing the sharp annular burr and thereby avoiding the severance of the yarn tail during the winding process, modern winding machines have been designed with a universal base plate which is adapted to receive carriers of various angles of taper, to thereby avoid the expense of changing base plates whenever a different style of carrier is being wound. While such universal base plates are efficient from this point of view, they create a further problem in that the yarn tail is often pinched by a non-flush fit between the inside end surface of the carrier and the base plate, and such pinching in turn often results in the severance of the yarn tail. This problem is particularly acute where the carrier includes a hardened inner end surface as described above, since the hardened nature of the inner end surface tends to aggravate the severity of the pinching problem.
Other solutions for the problem of severing the yarn tail have been proposed, note for example, U.S. Pat. Nos. 4,700,834 and 4,700,904, both issued to Martinez. These prior patents suggest the formation of spaced apart grooves, or grooves of crisscross configuration, or forming a ring of loose non-woven fibrous material of substantial thickness on the inside surface of the large end of the carrier. However, these rather elaborate constructions do not address the problem associated with the sharp annular burr as discussed above.
It is accordingly an object of the present invention to provide a yarn carrier, and a method and apparatus for manufacturing the same, which effectively avoids the above noted problem of severance of the yarn tail during the winding operation.