US3310248A - Yarn package winding method - Google Patents

Description

March 21, 1967 T HAVE YARN PACKAGE WINDING METHOD Filed Aug. 31, 1964 FIG.2

INVENTOR.

LAMBERTUS TEN HAVE United States Patent 3,310,248 YARN PACKAGE WINDING METHOD Lambertus Ten Have, Bennekom, Netherlands, assignor to American Enka Corporation, Enka, N.C., a corporation of Delaware Filed Aug. 31, 1964, Ser. No. 393,119 Claims priority, application Netherlands, Sept. 4, 1963, 297,508 1 Claim. (Cl. 242-43) This invention relates to a method of winding a yarn package and more particularly to a yarn package of greater size having uniform porosity and uniformly drawn filaments. The invention also relates to a unique yarn package produced by this method.

Heretofore yarn packages having uniform porosity and uniform yarn layer thickness have been produced. However, such packages have been restricted in their size and are undesirable from an economy standpoint. Uniformity in package buildup is highly desirable, particularly in the field of regenerated cellulose, in order to provide uniform aftertreatment of the packages as well as uniformity in denier strength and affinity for dyeing.

It is known in the thread winding art to mount a thread guide closely adjacent to a takeup spool onto which the thread is to be Wound and to reciprocate the guide longitudinally of the spool in order that the layers of the thread may be evenly distributed along the surfaces thereof. Disadvantages exist in this particular manner of thread packaging. In this type of apparatus, the thread is usually supplied at an angle substantially normal to the axis of the rotation of the spool by the reciprocating guide, passing first through a stationary thread guide or roller which is located centrally of the spool length and at a distance therefrom. When the reciprocating guide reaches the end portions of the spool during its reversing movement, the thread being fed from the stationary guide is displaced further and subjected to an increase in tension. This increased tension not only produces an unevenly stretched yarn, but also produces tension pulses which result in excess thread buildup on the end portions of the spool. This characteristic is sometimes referred to as saddle effect and results in nonuniform dyeing during liquid treatment and tends to cause the yarn to sluff off so that a self-supporting package cannot be produced.

Heretofore, these problems have been treated individually rather than collectively by industry. As one means for maintaining uniform porosity in a wound package, Whitaker, in Patent No. 2,608,354, has provided an apparatus for producing a stroke displacement during the winding cycle. Jackson Patent No. 2,338,723 has provided a means for preventing slutling of the ends of the package consisting of an apparatus for producing a stroke reduction during package winding. Additionally, Rutgers Patent No. 2,950,068 has dealt with saddle eifect by providing an apparatus for maintaining a constant thread travel distance between the fixed and traveling thread guides to prevent uneven tensioning of the yarn during windup. Also, British Patent No. 674,615 provides apparatus for varying the velocity of traverse of the yarn guide to improve package hardness.

In order that spinning machines can be still better utilized, a constant effort is being made to increase the weight of the yarn contained in yarn packages. This may be done most simply by increasing the length and/or diameter of the yarn package. However, when the spool length and traverse stroke of the reciprocating yarn guide are increased, the tension pulses in the winding thread become progressively stronger. As a result, the yarn is stretched nonuniformily, unevenly built up on the spool Patented Mar. 21, .1967

package, and produces a package having uneven porosity. Experimentation has indicated that by merely changing the traverse speed, the stroke displacement, and the stroke reduction, it is not possible to obtain a satisfactory package buildup in yarn packages of this large size. With the unique method of the present invention, however, it has nevertheless been found possible to wind the yarn into packages having much higher weight and which can be aftertreated very satisfactorily.

It is an object of the present invention to provide a yarn package of greater capacity and not possessing the aforementioned disadvantages.

A primary object of the present invention is to provide a method of producing larger yarn packages of self-supporting, uniformly thick layers having uniform porosity throughout the package. 7

An additional object of the invention is to provide a yarn package having increased weight, uniform porosity, and uniform yarn layer thickness.

These and other objects of the invention will become more obvious from the following detailed description and accompanying drawings.

The improved yarn package of this invention having greater weight without sacrifice of uniformity is produced bya method in which the reciprocating yarn guide, during its traverse stroke, is provided with an initial high velocity over a small part of the stroke length, followed by a subsequent velocity decrease over an approximate equal distance, and finally followed by a constant velocity level over the remainder of the stroke. Because of the relatively high initial velocity, the duration of the reversing movement at each end of the traverse stroke is reduced.

This quick traverse at the ends of the package results in decreased tension pulses and uniform buildup of the package. By coupling this quick reverse with the stroke reduction and stroke displacement, yarn packages of greater length having a greater yarn capacity can be produced without the heretofore mentioned loss in uniformity of the package.

The unique method involved can be more fully explained with reference to the accompanying drawings in which:

FIGURE 1 is a velocity-distance diagram illustrating theoretical speed increases and decreases during reciprocation of the thread guide along the yarn package; and

FIGURE 2 shows the course of the traversing stroke during winding operation, specifically illustrating the stroke displacement and stroke reduction.

FIGURE 1 depicts, by means of a velocity diagram, the speed of the traverse thread guide during a complete cycle of forward and backward movement from an end portion of a rotating spool. The solid line represents the traverse motion or stroke from an initial end position to the opposite end of the spool while the dotted line represents the return of the thread guide to its initial position. Distance D represents the total stroke length while distance A depicts the distance of initial high velocity followed by a decrease in velocity over distance B to a final constant velocity C throughout the stroke length with velocity C being 30 to 60% lower than the constant velocity at the beginning of the forward and backward strokes. In like manner, the return stroke, shown by the dashed lines,

. is initiated at the same speeds over correspondingly equivalent distances A, B and C. Although the distances A, A and B, B are necessarily small compared to the total stroke length, they may be varied within certain limits. It stands to reason that the reversal of direction is not completely instantaneous but it will be as nearly instantaneous as modern construction will allow. A highly uniform package may be producedby maintaining distance A and A between 4 to 8% of the total stroke length D and the distance B and B between 6 to 10% of the stroke length D.

FIGURE 2 is a schematic presentation showing the course of the traversing stroke during a complete package buildup. Distance G is the initial stroke length laid on the surface of a collection spool, while distance H indicates the final stroke length on the outer surface of the package. The stroke displacement is indicated by distance E and the stroke reduction by distance F. Although the stroke displacement and stroke reduction may be varied, a highly uniform package has been found to be produced by maintaining the stroke displacement and the stroke reduction at less than 10% and 20% of the length of the main stroke, respectively.

The method practiced in this invention will become more apparent from the following specific example. A package of increased weight and yarn capacity was pre pared from regenerated cellulose in which the collection spool length was increased from 180 to 255 mm. The package was wound using the traverse speed of 320 mm. per second, which resulted in unacceptable tension pulses in the yarn and consequent saddle effect at the ends of the package. By reducing the traverse speed to 255 mm. per second, the tension pulses were eliminated; however, it was not possible to obtain a self-supporting package with uniform thickness of the yarn layers and a uniform porosity by experimentally varying the stroke displacement and stroke reduction at this traverse speed.

A spool of the same length was then wound using the unique traversing method of this invention. At the beginning of every stroke, velocity of the thread guide was set to 450 mm. per second for a distance of mm. and decreased during the following mm. of travel to a constant speed of 255 mm. per second over the rest of the stroke length. During the winding of the package, the stroke displacement was set to 15 mm. and the stroke reduction to 38 mm. The main stroke of the traverse motion was set to 31 cycles per minute. The yarn package thus produced contained double the yarn weight of previously wound packages having the same uniform porosity, uniform yarn layer thickness, and equivalent self-supporting characteristics.

Inasmuch as other modifications will become apparent to those familiar with this art, it is intended that the scope of this invention be limited only to the extent of the following claim.

What is claimed is:

A method of winding a heavy yarn package on a rotating spool by the use of a traversing yarn guide incorporating a stroke reduction and a stroke displacement therein, said yarn guide laying successive layers of yarn on the spool by means of forward and backward strokes along the length of the spool, comprising the steps of:

(a) maintaining an initial high velocity of the thread guide at the beginning of each stroke at each end of the collection spool for a distance 4 to 8% of the stroke length;

(13) decreasing the velocity of the guide for a distance of 6 to 10% of the stroke length;

(c) maintaining a decreased constant velocity of the thread guide for the remainder of the stroke length 30 to lower than the constant velocity at the beginning of the forward and backward stroke; and

(d) maintaining the stroke displacement and the stroke reduction less than 10% and 20% of the initial stroke length, respectively.

References Cited by the Examiner UNITED STATES PATENTS STANLEY N. GILREATH, Primary Examiner.

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