Winding – tensioning – or guiding – Helical or random winding of material – Including particular material to spool connection
Reexamination Certificate
2000-05-15
2001-10-30
Mansen, Michael R. (Department: 3653)
Winding, tensioning, or guiding
Helical or random winding of material
Including particular material to spool connection
C242S476400, C242S477900
Reexamination Certificate
active
06308906
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a method of winding a continuously advancing yarn to a cross wound package, and so as to form a yarn reserve wind at the beginning of the winding cycle.
EP 0 311 827 and corresponding U.S. Pat. No. 4,948,057 disclose a winding method wherein an advancing yarn is wound on a driven tube which is clamped between two centering plates. The centering plates are rotatably supported. The tube lies against a drive roll, and is driven by same. After the tube has reached a predetermined winding speed, the yarn is caught and cut by a catching groove, which is arranged in the circumferential region of one centering plate. The loose yarn end is taken in by a suction device. After initial layers of the yarn have been wound on the tube laterally next to the winding range to a so-called yarn reserve wind, winding of the package starts. For catching and winding initial layers, the yarn is guided by a movable yarn guide.
Takeup devices of the described type are used, for example, in texturing machines for winding a textured yarn to a package. To this end, the continuously advancing yarn is caught before the winding start, cut, and deposited on the tube with a yarn reserve wind next to the actual winding range. In this connection, the yarn reserve wind forms the trailing yarn end of the package, which is knotted in a further processing operation to the leading yarn end of a second package. This makes it necessary to secure the yarn end on the tube surface in an easily recognizable and reliable manner. In the known method, the yarn is clamped at the front end of the package between the centering plate and the tube, so that after the package doff, the yarn end is no longer clamped. After completing the package and after doffing the package, there arises the problem that the yarn end disengages from the yarn reserve wind, and leads in the extreme case to a complete unwinding of the yarn reserve.
It is therefore an object of the invention to further develop a method of the initially described type in such a manner that the yarn end is reliably secured on the circumference of the tube, even when the packages are removed.
A further object of the invention involves depositing the yarn end on the circumference of the package with clear identification marks.
SUMMARY OF THE INVENTION
The above and other objects and advantages are achieved by the provision of a method of winding a continuously advancing yarn which comprises initially forming a yarn reserve on the tube outside the winding range by guiding the advancing yarn with a yarn guide which is moveable substantially parallel to the tube. The yarn guide is moved by a controllable drive such that the yarn guide is reciprocated to secure the trailing yarn end on the circumference of the tube with at least some of the winds of the yarn reserve. The advancing yarn is then wound onto the tube within the winding range to form a cross wound package.
The invention makes it possible to influence the winds in their slope, as well as in their direction of deposit. To this end, the yarn guide may be moved to reciprocate at different guiding speeds, which renders it possible to influence the slope of the yarn wind on the tube surface. In this connection, the higher the guiding speed, the steeper is the slope of the wind. The direction of the yarn deposit is dependent on the direction of movement of the yarn guide. Thus, at each change in direction of the yarn guide, the reciprocating movement causes a change in the direction of deposit of the winds on the tube surface.
When winding dye yarn packages (subsequently dyed packages), it is often necessary to wind a waste wind within the winding range, before winding a yarn reserve wind. Subsequent thereto, the yarn reserve is produced outside of the winding range, so as to start thereafter the actual winding cycle. These sequences of movements produce on the tube surface a plurality of wind transitions between the yarn reserve wind and the package. Since the leading yarn end with the waste wind is unsuitable for further processing, the trailing yarn end of the package is formed by the yarn reserve wind that is produced after the waste wind. The invention makes it easy to identify the yarn end after completion of the package. To this end, the yarn winds that are produced in a forward movement and a return movement between the package and the yarn reserve wind, are deposited with different slopes on the circumference of the tube. This is realized by carrying out the forward and the return movement of the yarn guide at different guiding speeds. The special advantage of this invention lies in that no waste yarn is included in the further processing operation.
In one embodiment of the method, the forward movement occurs in the transition of the yarn guide to the winding range before producing the waste wind, at a higher guiding speed than the return movement performed by the yarn guide after producing the waste wind. With that, the yarn end of the yarn reserve wind produced during the return movement, is deposited on the tube with a gentle slope, so that for forming the yarn end, it is possible to cut the yarn within the wind with a gentle slope.
However, it is also possible to perform the return movement of the yarn guide at a higher guiding speed than the forward movement. With that, the yarn end is to be formed with the yarn wind, which is deposited with a steeper slope between the yarn reserve and the package.
In the production of dye yarn packages, it is also common to wind a first yarn reserve wind before winding the waste wind. Such a first yarn reserve wind can be deposited inside or outside of the winding range. When winding outside of the winding range, it is preferred to wind the two yarn reserve winds in the same place on the tube circumference. This ensures that the second, relevant yarn reserve wind also exhibits a uniform dyeing as is required for further processing.
To secure the yarn end of a yarn reserve wind in an advantageous manner, the yarn guide may be operated at the beginning of the yarn reserve wind in a forward movement and a return movement directly following the forward movement. The forward movement occurs at a higher guiding speed than the return movement, so that the steep yarn wind deposited on the tube surface during the forward movement, is wound over by the winds following during the return movement. With that, it is realized that the yarn end is secured on the circumference of the tube by a plurality of side-by-side winds.
To secure the yarn end on the circumference of the tube with parallel winds, the distances covered by the yarn guide in its reciprocating movement may be different. Thus, a greater distance is covered in the forward movement than in the return movement, so that the winds deposited in the forward movement are covered by the winds produced in the return movement.
Another variant of the method is especially suited for securing the yarn with a minimal length of the yarn reserve wind. In this connection, the forward and return movements of the yarn guide occur briefly within a wind deposited on the tube, so that the deposited wind is directly wound over by a following wind.
The method of the present invention can be used with advantage in all known takeup devices. Thus, it is possible to transfer the yarn after a winding start from the yarn guide to a traversing yarn guide of a yarn traversing device, so that the yarn guide guides the yarn only during the catching and during the winding of the yarn reserve. However, it is also possible that the yarn guide guides the yarn during the catching, winding start, and winding, so that the yarn guide is simultaneously used a traversing yarn guide. Essential is that the movement of the yarn guide can be controlled by a controllable drive at a variable speed independently of the direction.
REFERENCES:
patent: 4948057 (1990-08-01), Greis
patent: 0 311 827 A2 (1989-04-01), None
Lieber Reinhard
Pyra Michael
Alston & Bird LLP
Barmag AG
Mansen Michael R.
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