US 3284023 A
Description (OCR text may contain errors)
Nov. 8, 1966 L. H. SOWELL 3,284,023
TEXTILE CORE WITH A YARN ENGAGING GROOVE Filed Dec. 15, 1965 FIG-l INVENTOR LYLES HOWARD SOWELL.
BY MZM ATTORNEY United States Patent 3,284,023 TEXTILE CGRE WITH A YARN ENGAGING GRGOVE Lyles Howard Sowell, Madison, Tenn., assignor to E. l. du Pont de Nemours and Company, Wilmington, Del, a corporation of Delaware Filed Dec. 15, 1965, Ser. No. 513,942 4 Claims. (Cl. 242-1251) This invention relates to cores or bobbins on which yarn filaments and the like may be wound and unwound, and more particularly, to an improvement in the construction thereof by means of which a moving yarn may readily and effectively be caught and held by the rapidly rotating core to commence the initial phase of the winding operation.
In industrial operations, yarn producers customarily wind their yarns on spools or cores to form a package suitable for shipment. Modern high-speed production methods entail efiicient processes whereby a continually advancing yarn is wound onto successive, rapidly rotating bobbins or cores. The customary process sequence involves passing the yarn which is continually advancing from a source, such as a spinneret, through the intake nozzle of a sucker gun such as disclosed in Miller US. Patent No. 2,667,964, dated February 2, 1954, frictionally engaging the incoming yarn with a rotating core or bobbin so as to cause incipient winding of the yarn onto the core and simultaneously breaking of the yarn at a point between said nozzle and the point of frictional engagement. Upon formation of the package, the advancing yarn is caused to pass through the sucker gun nozzle which causes the yarn to break. The package is replaced by an empty core and the sequence is repeated. The point of engaging frictional contact on the core is preferably near one end thereof and some distance from the near edge of the normal traverse of the yarn during package build-up. Hence, the package contains a transfer tail, e.g., a number of helical windings of the initial yarn which are not covered by other yarn in the package. This makes possible the formation, in essence, of an endless yarn of any number of packages by tying the transfer tail of one package to the yarn end on the periphery of another package.
From the above process description, it can readily be appreciated that proper core design is essential to the establishment of effective initial engagement of the yarn thereon and, in a wider sense, to the practical attainment of manufacturing objectives.
Various core designs have been tried, such as the provision of a circumferential groove in the core, adhesive substances on the face of the core, and various devices replaceably affixed on the core surfaces. However, such cores have failed seriously when used for catching and winding strong, high-denier yarns at extremely high speeds of the order of 10,000 ft./min. (3048 m./min.). These failures are attributable to the fact that grooves and adhesives do not provide sufficient frictional surfaces for the high-strength yarn to be initially engaged and broken at such high speeds, so that effective winding is impossible. Moreover, devices replaceably afiixed to the core surface, in addition to being expensive, are subject to relatively large centrifugal forces when the core is rotated at very high speeds, a condition which causes the devices to fly off the core in a very hazardous manner. To illustrate, the centrifugal force developed by a l-ounce (28.35 gm.) object on the face of a 1-inch (2.54 cm.) radius core rotating at 17,000 revolutions per minute-an effective winding speed actually attained in accordance with this inventionis approximately 520 lbs. (2314 newtons).
The present invention provides a core of improved design for winding yarns, threads and the like. A further provision is a textile core which is both inexpensive and highly suitable for winding high-denier, high-strength yarns at extremely high speeds. Other provisions will be apparent from the following specification and claims.
The textile core of the present invention has, in its exterior surface, near one end, a circumferentially disposed V-shaped groove of substantially uniform depth,'extending around the core in a plane perpendicular to the axis of rotation of the core, the sides of said groove being either convexly curved or straightly extending inward and converging toward each other to meet or substantially meet in an acute angle at the bottom of the groove. The groove has, along its length, a plurality of yarn traps for catching yarn in the groove and for breaking off the lead end of the yarn. The traps are structural distortions in at least one side of said groove, each distortion essentially comprising a protuberance extending from one side of the groove in which it is formed, and having its locus between the bottom of the groove and a point lying approximately of the shortest distance from said bottom to a straight line connecting the groove edges at the groove opening, a portion of the face of the protuberance substantially touching the groove side which is opposite to it. 1
The term core as used herein refers to a supporting means for forming a yarn package, comprising an elongated rotatable body having an axis of rotation and a curved outer surface, the periphery of the core being circular at transverse sections taken perpendicular to the axis of the core. The core is normally hollow to permit its placement on a chuck or other means for rotating the yarn package which is being formed.
This invention will be more fully understood by reference to the accompanying drawings in which: 7
FIGURE 1 is an isometric view of a core constructed in accordance with this invention.
FIGURE 2 is a partial cross-sectional view of taken on line 22 of FIGURE 1.
FIGURE 3 is a partial cross-sectional view of taken on line 33 of FIGURE 1.
FIGURE 4 is a partial cross-sectional view corresponding to FIGURE 2 but showing a modified form of the invention.
FIGURE 5 is a partial cross-sectional view corresponding to FIGURE 3 but showing another modification of the invention.
Referring to the figures, FIGURE 1 shows core 1 con taining a groove 2, placed near the core-end 3, which has yarn traps 4. FIGURE 2 shows a typical groove or notch 2 having an opening 5 and a bottom 6. FIGURE 3 shows a yarn trap, constructed in accordance with the preferred embodiment of the present invention, having an opening 5, a bottom 6, a protuberance 7 and a depressed surface 0. FIGURE 4 shows a simple yarn trap having an opening 5, a bottom 6 and a protuberance 7. FIGURE 5 shows a yarn trap having an opening 5, a bottom 6, a protuberance 7 and two depressed surfaces 8 and 9.
The core may be fabricated from any suitable material, paper or molded plastic being preferred.
The term groove as used herein refers to a V-shaped notch or opening in the core, the sides of which are either convex curves or straight and extend inward toward the axis of rotation of the core to substantially meet at the bottom of the groove. The groove completely encircles the core in a plane perpendicular to the axis of rotation. The depth of the groove, i.e., the distance that the groove penetrates into the core, may be from approximately 0.03 inch (0.0762 cm.) to slightly less than the thickness of the core, or in the case of a solid cylindrical bobbin, to approximately 0.125 inch (0.3175 cm.) less than its rathe core,
dius. Preferably, the depth of the groove is approximately 0.078 inch (0.1981 cm.) in a core of approximately 2-inches (5.08 cm.) outside diameter and approximately 1.66-inches (4.22 cm.) inside diameter. The opening of the groove, i.e., the length of a straight line connecting each point of intersection (or tangency, if the groove edges are rounded) of the groove sides with outer core surface adjacent to said sides may be of any length customarily used in the art to accommodate the diameter of the yarn to be used. Preferably, if the groove edges are not rounded the opening is approximately 0.015 to 0.1 inch (0.0381 to 0.254 cm.) when dealing with ISO-denier, 34-filament polyethylene terephthalate yarns. Greater groove openings are used when the edges of the groove are rounded.
The geometry of the yarn trap, i.e., the structure designed to catch the yarn in accordance with the present invention, is essential to the invention. The yarn trap substantially comprises a protuberance extending from at least one side of the groove in which it is formed. A simple yarn trap suitable for the practice of this invention is shown in FIGURE 4. The protuberance, which may be of any shape, must be situated between the bottom of the groove and a point lying approximately of the shortest distance from said bottom to a straight line connecting the groove edges at the groove opening. Further, the protuberance must substantially touch the op posite groove side. Preferably, when using the abovespecified yarns, the protuberance is situated approximately in the lower /5 of the depth of the groove, and the face of the protuberance actually touches the opposite groove side. It is preferred that the protuberance be placed in the groove side which is farther from the core end nearer to the groove.
Surprisingly, it has been found that the width of the protuberance, measured along the length of the groove, should be less than 0.25 times the circumference of the core or bobbin. Preferably, the width of the protuberance is approximately 0.017 times the circumference of the core.
Subject to the above limitations in the geometrical design of the yarn trap, many modifications will be apparent to those skilled in the art. The stnuctural modifications envisioned will primarily be the result of the methods used to form the protuberance. For example, referring to FIGURE 3, the surface 8, which is an inward depression in the outer face of the core and in the groove side containing the protuberance, results from a convenient process whereby the edge of the groove is stamped or pressed or otherwise depressed in order to form the protuberance. Further, FIGURE 5 shows the depression in the outer face of the core occurring in both groove sides. All of these structures are intended to lie within the spirit and scope of the present specification. It is preferable, however, that the depressed surface be located entirely in the groove side containing the protuberance.
In using the core for winding a package, the yarn is first caused to pass through the nozzle of a socker gun and is placed in a position to be engaged by a traverse means. As soon as the yarn is so engaged, it is placed, by moving the sucker gun, so as to come in contact with the new core at a wrap angle of from approximately 90 to 180. The direction of yarn motion is opposite the direction of peripheral rotation of the core. The yarn is quickly caused to come into contact with the groove of the core. As the core rotates, the yarn is engaged by at least one of the traps and is subsequently broken. The yarn is then guided by traverse means to be helically wound around the core. The traverse means is preferably adjusted so that the edge of the package closest to the groove will be an appreciable distance from the groove, preferably 0.25 inch (0.635 cm.). Thus, the Winding forms a traverse tail as described above.
Usually only a portion of the filaments of the yarn are caught in the first trap the yarn meets, and all of the filaments are caught in the second trap. Thus it is essential to the invention that there be more than one trap in the core. Preferably, the core contains six traps.
Any synthetic, man-made, or natural fiber may be used in the practice of this invention. Continuous-filament yarn as Well as staple-spun yarn may effectively be used.
The following example will illustrate one way of practicing the invention, although it is not intended to limit its scope.
Example A spirally wound, cylindrical kraft-paper textile tube ll-inches (27.94 cm.) long and having an inside diameter of 2.015 inches (5.118 cm.) and an outside diameter of 2.327 inches (5.911 cm.) is grooved with a knife. The single groove is approximately 0.375 inch (0.953 cm.) from one end of the tube. The groove is 0.0781 inch (0.1984 cm.) deep and has rounded edges (approximately 0.0312-inch (0.0792 cm.) radius). The groove opening is approximately 0.0665 inch (0.1639 cm.).
Six yarn traps (two series of 3 traps each, the middle trap of each series being 0.375 inch (0.8525 cm.) from the traps adjacent to it, the angular distance from the middle trap of one series to the middle trap of the other being 180) are formed in the core by punching the groove edge which is farthest from the near end of the core. The punch has a 0.125-inch (0.3175 cm.) diameter flat circular face. The core having the traps therein substantially resembles the illustration in FIGURE 1. The depth of each depression in the core surface made by the punch is approximately 0.047 inch (0.119 cm.) and the crosssection of the traps, thus formed, resembles the illustration of FIGURE 3. A portion of the face of each protuberance of the traps touches the opposite groove side.
Twenty cores are constructed as above and evaluated for string-up efiiciency. (String-up efliciency is defined as the percent successful string-up attempts versus the number of total attempts, unsuccessful attempts versus the number of total attempts, unsuccessful attempts being those in which the yarn breaks without initial package formation, or attempts in which package build-up cannot be initiated at all.) The tubes are mounted to be surface driven by means of drive rolls. The yarn used for this example is ISO-denier, 34-filament polyethylene terephthalate having a tenacity of 4.5 grams per denier. The peripheral speed of the tubes is approximately 3000 yards per minute (2743.2 m./min.). The yarn is taken into a sucker gun and brought into contact with the core as described above at a wrap angle of approximately String-up efliciency is greater than 99%.
For comparison, a series of tubes constructed as described above with the exception that no yarn traps are present therein, is tested for string-up efiiciency. An
identical yarn is used and all other procedures are followed. String-up efficiency is approximately 5%.
Thus, in the process of winding high-denier, highstrength yarns, threads and the like, the tremendous advantage of the practical, eificient and economical enablement of high-speed operation is realized by the use of cores or bobbins embodying the improved features of the present invention.
Since many different embodiments of the invention may be made without departing from the spirit and scope thereof, it is to be understood that the invention is not limited by the specific illustrations except to the extent defined in the following claims.
1. For use in winding yarn packages at high speed, a textile core having a cylindrical body for supporting the yarn, a circumferential groove near. one end of the body for engaging yarn when starting to wind a package, said groove being a generally V-shaped notch of substantially uniform depth in the exterior surface of the body and aligned in a plane perpendicular to the cylinder axis of the body, the opposite sides of the groove converging to meet in an acute angle at the bottom of the groove, and a plurality of yarn traps along the groove for catching yarn in the groove and for breaking off the lead end of the yarn to start a package, each of said traps comprising a protuberance on one side of the groove which substantially touches the opposite side of the groove, is situated in the lower A of the depth of the groove, and has a width measured along the groove of less than 0.25 times the circumference of the body.
2. A textile core as defined in claim 1 wherein the yarn trap comprises a portion above said protuberance which is a circular depression in the surface of the cylindrical body and has a width approximately 0.017 times the circumference of the body.
3. A textile core as defined in claim 1 wherein said UNITED STATES PATENTS 1,924,510 8/1933 Parks 242-125.2 2,258,900 10/1941 Little et a1 242-125.1 2,262,665 11/ 1941 Cavanaugh 242125.1 3,103,305 9/1963 Heatherly 225-6 FRANK I. COHEN, Primary Examiner.
G. F. MAUTZ, Assistant Examiner.