Abrading – Abrading process – Roll – roller – shaft – ball – or piston abrading
Reexamination Certificate
2001-03-01
2002-07-09
Hail, III, Joseph J. (Department: 3723)
Abrading
Abrading process
Roll, roller, shaft, ball, or piston abrading
C451S028000, C451S041000, C493S296000, C493S293000, C242S118320
Reexamination Certificate
active
06416396
ABSTRACT:
TECHNICAL FIELD AND BACKGROUND OF THE INVENTION
This invention relates to an apparatus and method for milling the end surfaces of textile packages, and is particularly useful in grinding away the sharp edges formed on the base end of paper textile cones and tubes in order to prevent yarn tail breakage during yam winding. Winding takes place in open-end spinning, ring spinning, twisting and other processes wherein yarn is wound onto the yarn packages. Yarn packages used in these processes are wound with a trailing “tail” of yarn by which the end of yarn on an exhausted package is tied to the leading end of yarn on the succeeding full package. The tail is necessary if the transfer from the exhausted to a full package is to take place without dropping needles, which causes a serious defect in the knitted fabric.
While the invention disclosed in this application has utility on a number of different types of yarn packages, for purposes of illustration the invention will be described with reference to a tubular textile yarn package which is formed of pressed paper and has a generally frusto-conical shape. While packages come in various configurations, one common type of package is a cone which has an angle of taper of 5 degrees, 57 minutes.
As described above, this type of package must be wound with a tail in order for it to be considered a first quality package. An acceptable rate of yarn tail breakage is about one percent, with between two and three percent being average. Since knitters require yarn packages with yarn tails, yarn tail breakage is a serious problem both from the standpoint of yarn quality and from the standpoint of increased cost to the processor which results from backwinding defective packages, returns from customers, and the like.
The yarn tail is usually formed by taking a length of yarn and extending part of it over the open mouth of the large end of the package. The package is then applied to a cradle which has a package holder base plate which fits into the large end of the package and holds the yarn, and a package holder nose plate which secures the package for proper rotation about a fixed axis. See FIG.
12
. The package is wound by surface drive against a rotating drum which feeds the yarn onto the rotating package in a predetermined pattern. This assembly is referred to generally herein as a “yarn package holder.”
Until relatively recently, winders were designed so that the package holder base plate had an internal taper which corresponded to the taper of the package. This meant that for a fairly substantial distance on the order of 6 mm, the surface of the package holder base plate and the inner surface of the package were parallel with each other and in flush contact. The yarn trapped across the mouth of the package was thereby held firmly along the entire length of contact between the package and the base plate. This resulted in a secure grip while, at the same time, any stress applied to the yarn was spread over a relatively long distance.
Some winder manufacturers have designed cradles which have universal package holder base plates and nose plates. The plates are adapted to receive packages having various angles of taper without the additional labor and lost operating time required to conform the cradle to the precise type of package being wound. While substantial efficiencies are achieved by this new type of winder, the angle of the portion of the base plate which fits into the large end of the package is no longer necessarily parallel to and flush with the inner surface of the package. Therefore, the yarn tail passes between the package and the base plate at two diametrically opposed edges rather than wide, flush surfaces. As long as there is little or no relative movement between the base plate and package, this fact is of little consequence. Therefore, when starting an empty package, there is often little difficulty since the package itself is very lightweight and has very little inertia.
Accordingly, the package begins rotation with the base plate and there is little or no relative movement which could cause the yarn to be pinched or cut. However, as yarn is wound onto the package, it increases substantially in weight and inertia. Many winders have automatic stop motions which utilize, for example, an air brake to very quickly stop the rotation of package when the package is full or when a break in the yarn occurs. The substantial inertia created by a full or near-full package is sufficient to cause the package to rotate relative to the base plate during stopping and starting. In the new types of winders described above, the edge of the base plate which presses against the yarn exerts a substantial amount of force and is more than sufficient to cut the yarn in two. As a result, the yarn package is no longer first quality and must either be rewound or sold as second quality.
Murata winders are widely used in the textile industry and present a unique, potential cause of yarn tail breaks. Murata winders include a rubber drive ring which sits on one end of the yarn package holder and, when the package is donned, sits against the adjacent end of the package. The drive ring contacts the driving surface of the drum during the initial winding phase and causes the package to rotate. When enough yarn has been built up on the package, the diameter of the package becomes greater than the diameter of the drive ring, and thus the package is thereafter rotated by direct contact between the package and the drum.
It has been observed that the rubber ring will sometimes cut the yarn tail both during starting and stopping due to the contact between the rubber ring and the end edge of the package across which the yarn tail extends. The problem has become progressively worse as the winding speed of modern winders, open-end spinning machines, twisters, and the like have increased.
Applicant has reduced this problem to a significant extent by modifying the design of the package to incorporate grooves into the end of the packages which protect the yarn by providing a slight recess in which the yarn at least partially resides thereby reducing the force on the yarn. This development is exemplified in applicant's prior U.S. Pat. No. 4,700,904.
Paper textile packages have improved in quality in recent years by reducing manufacturing tolerances to provide packages with very little variation from package to package. This has resulted in precisely cut surfaces which leave sharp edges which can easily cut through a yarn as a result of even momentary contact. For example, the end of a paper cone thus has a very flat base with very sharp edges on the inner and outer sides. These edges must be “eased” slightly in order to prevent loss of transfer tails, as described above. The invention disclosed in this application permits this to be done quickly, inexpensively and automatically during package manufacture by milling these sharp edges away without effecting the quality of the package. The milling takes place during a grinding process, and thus the term “grinding” is used generically in this application to describe in general a process by which very sharp edges are eased to prevent yarn cutting. The grinding performs two functions. It removes the sharp edges and also leaves a slightly roughened, fuzzy surface caused by tearing loose paper fibers on the surface of the package. The rough surface provides a “nest” within which the yarn is positioned, protecting it from abrasion and breaking.
SUMMARY OF THE INVENTION
Therefore, it is an object of the invention to provide an apparatus and method for milling the end surfaces of textile packages which is particularly useful in grinding away the sharp edges formed on the base end of paper textile cones and tubes in order to prevent yarn tail breakage during yarn winding.
It is another object of the invention to provide a apparatus and method for milling the end surfaces of textile packages which grinds away sharp surfaces on the end, and inner and outer edges of the base of a textile package simultaneously.
It is another object o
Adams, Schwartz & Evans P.A.
Berry Jr. Willie
Conitex-Sonoco LLC
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