US2714812A

US2714812A - Method of controlling wildness of twisted yarn during delivery to a knitting operation

Info

Publication number: US2714812A
Application number: US503070A
Authority: US
Inventors: William J Leath; Jr Frank E Bobo
Original assignee: Individual
Current assignee: Individual
Priority date: 1955-04-22
Filing date: 1955-04-22
Publication date: 1955-08-09
Anticipated expiration: 1972-08-09

Description

Aug. 9, 1955 w. J. LEATH ET AL 2,714,812

METHOD OF CONTROLLING WILDNESS OF TWISTED YARN DURING DELIVERY TO A KNITTING OPERATION 3 Sheets-Sheet 1 Filed April 22. 1955 igzj INVENTORS H" M Ma m 5 m m fln K MN M" wr Aug. 9. 1955 w. .1. LEATH ET AL 2,714,812

METHOD OF CONTROLLING WILDNESS OF TWISTED YARN DURING DELIVERY TO A KNITTING OPERATION Filed'April 22, 1955 3 Sheets-Sheet 2 6 FI/L L.

90" FULL 0R EMPTY I I I J INVENTORS WILLIAM J, L -m FRANK E. BOBQJR.

ATTORNEKS' Aug. 9, 1955 METHOD OF CONTROLLING WILDNESS OF TWISTED YARN DURING DELIVERY TO A KNITTING OPERATION Filed April 22, 1955 w. J. LEATH ET AL 2,714,812

3 Sheets-Shea t 3 FIE. n

dun-2:55....

FIGS. A B C D F3" .25. 8 & l0 2.0625 4.125" 1/25" 5.0 J INVENTORS I/ 9 5555A. 4625 3'62 1 WILLIAM J. LEATH ATTORNEY-9 United States Patent NIETHODOF CONTROLLING WILDNESS OF TWISTED'YARN DURING DELIVERY TO A "KNITTING OPERATION William J. Leath, Charlotte, N. C., and d Frank E. Bobo, Jr., Gainesville, Ga.

Application April'ZZ, 1955, Serial N0."503,070

'4 Claims. (Cl. 66- 146) nylon or other yarn a lively or .wildness'characteristic which will result in stretchable properties in knitted fabric formed of this yarn.

Another commercially valuable feature of this invention is the handling ofthe twisted nylon yarn in such a manner tharits wildness characteristic is kept under conirol when the yarn is, delivered from the carrier on wh ch it is wound, to the knittingmachine so that it will not snarl or become tangled or kinked between the time that it-isdelivercd or unwound from the carrier, and is knitted intb the fabric.

The twisted and treated'yarn produced in accordance with this invention has unique and novel characteristics distinctly different ,from twisted yarns proposedheretofore for: use in stretchable hose or other stretchable'fab- 'rics. The prior forms. of stretchable yarn are characterized by multitudinous deformations in the yarn. These deformations maybe in the form of crimped portions or in the form of a number of finecoils similar in shape to a coiled spring; or they may have a coil construction similarto a corkscrew, as well as other varying forms.

T he-novel yarn of the present invention is characterizcd by its freedom from coils and absence of crimped or other such deformations in the yarn. On the contrary, the yarn of this invention has a smooth, continuous, substantially straight form and exhibits little or no elasticity or stretchability of the yarn as such, and, furthermore, does not depend upon the elongation of coils or crimps in the yarn, to provide a stretchability property in the hose or other knitted fabric produced from this yarn.

The stretchable property in hose or fabrics knitted from this yarn is obtained from the lively or wildness characteristic of the yarn that is controlled temporarily during the knitting operation, but which after knitting causes the loops or-stitches in the hose or knitted fabric to deform or orient out of their normal positions, and yet upon stretching of the fabric permits these stitches or loops to orient into their normal positions. This movement or change-in disposition of the loops or stitches provides the novel stretchable characteristics in the knitted product.

The methodof twisting the yarn to produce; the lively characteristic in accordance with the present invention comprises, generally, a first twistingof one end of the nylon yarn, multifilament or monofilament, invone direetion, sayto the right. so asto provide an S twist, then heating to a temperature suflicient to set the yarn and which temperature will be higher than all subsequently encountered temperatures in the treatment of, the yarn orproduct made therefrom, followed by twisting the yarnin-the opposite direction, that is to the left, and providing therein a Z twist. This reverse or back-twisting operation will determine principally the amount of livescribed above prior to hea liness or wildness in the yarn and the extent of twist will depend upon the degree of this'property desired in the yarn. I g

The first twist applied to the yarn as described just above may vary substantially invextent, or number of twists applied, a typical range being 10 to 50 turns twist per inch. At the end of this first twisting operation, the twisted yarn will possess a substantial livelincss or wildness sufficient to form a stretchable fabric, upon knitting or weaving. However, subsequent high temperature treatments of thetwisted yarn or fabric produced therefrom, such as normally occur in the manufacture of fullfiishioned hosiery, would substantially remove the lively characteristics and stretchability of theyarnor fabric because of the fact that the yarnat this stage, immediately after the first twisting, has; not been set with heat. Thus it is important in carrying out the method of this invention, to incorporate a heat-setting of the nylon yarn at an appropriate point and to have this heat-setting operation carried out at a temperature appreciably higher than any subsequently encountered temperature.

As above indicated, it is important, and in fact essential, to heat-set the yarn at the propertiine and at an adequate temperature to avoid losing the lively effects induced in the yarn by the twisting operation when the hose knitted therefrom are subjected to subsequent higher temperature treatments; In the method of this invention,.this heat-setting treatment may be carried out after the first twisting operation and prior to the second or .back-twisting operation and, in fact,.this is the presently preferred procedure. However, worthwhile benefitsmay be obtained from the method of this invention when .carried out as described aboveexcept for changing the time or point in the process of heat-setting operation. For example, we have produced yarn having substantial stretchability and produced ladies full-fashioned hose therefrom, in which the heat treating operation was applied to the yarn prior to twisting of the yarn. In this modification, no second or reverse twisting of the yarn is required; only the initial heat treating, followed by twisting the desired number of turns such as, for example, about 10 to 50 turns per inch. I

in the manufacture of nylon full-fashioned hosiery, the twisted yarn would usually be heat-set at'a temperature of about 270 F. for a sufficient length of time, e. g., one half hour, to effect the desired heat-setting. This heat setting temperature could be higherif desired, but the important point is the use of a temperature sufficiently higher than the subsequent processing temperatures to avoid damaging effects of the latter. In the manufacture of full-fashioned hosiery, the subsequent processing temperature encountered in the dyeing and finishing operations are in the order of 250 F. or about 20 lower than the above-mentioned 270 heat-setting temperature which is found to be a safe margin. 1f the subsequcni temperature equals or exceeds the previous heabsetting temperature, the twist effect in the yarn will be substantially completely lost.

Another important feature of the twisting and'heatsetting operations of this invention is that of twisting the yarn adequately following the first twisting and heatsetting operations, because the-heat-setting operation substantially removes or neutralizes the liveliness imparted to the yarn by the first -twisti'ng operation. This "being the yarn, after heat-setting, requires furthcr'twisting ti; effect the desired liveliness. The amount of twisting employed after heat-setting will depend upon the desired degree of liveliness or stretchability desired in the yarn or fabric made therefrom. This twisting 'after heat-setting may vary substantially as to the number of twists and may be of the order of thefirst twisting operation de- 3 less than the first twisting operation, e. g., to 60 turns twist per inch. A typical example of the twitsing operations that has given very good results. is a'first twist of turns per' inch followed by heat-setting and then.a backtwisting of 23 turns per inch. v

Also, it is usually of advantage to employ in this second twisting operation, a twist that is opposite in direction to the original twist, i. e., a Z twist for the second twisting operation where an S twist has been employed in the original twisting operation. A reverse or backtwist of this type, after heat setting, will increase desirably the liveliness in the yarn as compared to a continuation of twist in the same direction as the original twist. Furthermore, the strength and other physical properties of the yarn will be better maintained by use of a reverse or backtwist for the second twisting operation. I

When multifilament yarns are used in these twisting operations, it is desirable to extend the reverse or backtwisting operation at least some few turns more or less,

than the twist in the original twisting operation, so that the several filaments comprising the yarn will be integrated more completely by the additional turns twist than would be the case if the backtwist'equaled the forward twist and left the filaments in substantially untwisted or parallel position. ment yarns in 30 turns per inch for the forward twist and 37 or 23 turns per'inch for the backtwist.

Further specific but non-limiting examples of the twisting and heat-setting operations described generally above, which we have employed satisfactorily in the production of yarn for knitting ladies sheer nylon stretchable hose, are as follows:

One end of monofilament nylon yarn is twisted 30 turns per inch in a Z or left twist direction. Another end of the same type nylon yarn is twisted 30 turns per inch in an S or right twist direction. twisted nylon yarns are subjected to treatment with live steam in suitable equipment such as a pressure or vacuum retort and at a temperature of approximately 265 F.- 270 F. for a sufficient length of time to effect proper penetration. After this treatment with live steam, the yarn is transferred to twister bobbins and twisted 23 turns per inch in the oppiste direction of the originaltwist. The resultant twisted yarn is wild, in that it inherently snarls when delivered from the bobbin and this In conjunction with the present invention we have discovered a method and means for solving the difficult problem of controlling the lively characteristic of the twisted nylon yarn. during the delivery of the yarn from the yarn carrier to the knitting machine. This new and improved procedure comprises the feature of delivering or unwinding the twisted yarn, from its carrier, in a direction opposite to the direction of the twist previously applied to the yarn. The'yarn delivery means also comprises training of the yarn end over and around a novel projection or draw cap associated with the yarn spool, tube, or cone, to restrain the yarn, and tensioning means cooperating therewith to maintain the yarn in a straight disposition between the spool, etc. and the knitting machine. In this connection it was found necessary to establish certain critical relationships between the dimensions of certain elementsof the yarn package and draw cap and also between the spacing of the draw cap and first eyelet of the yarn tensioning means in order to prevent snarling and breaking of the yarn and thus make it possible to knit the yarn.

Further details of the present invention will be understood from the following description taken in conjunction with the accompanying drawing, in which:

Fig. l is an elevational view of a yarn carrier in the form of a double head spool and having wound thereon a supply of yarn previously twisted in a left or counter- An example of twists used with the rnultifila- These two separatelyclockwise direction, and arranged to deliver the yarn therefrom in a right or clockwise direction;

Fig. 2 is a bottom end view of the carrier shown in F Fig. 3- is an elevational view of a yarn carrier of the same type shownin Fig. l and having wound thereon a supply of yarn previously twisted in a right or clockwise direction, and arranged to deliver the yarn therefrom in a left or counterclockwise direction;

Fig. 4 is a bottom end view of thecarrier shown in Fig. 3;

Fig. 5 is an elevational view of a draw cap adapted to be mounted on the bottom end of the yarn carrier as shown in Figs. 1 and 3;

Fig. 6 is an elevational, exploded perspective view of a hanger and key for use in mounting the yarn carrier as shown in Figs. 1 and 3;

Fig. 7 is a diagrammatic view partly in cross section of a yarn carrier, such as shown in Figs. 1 and 3, and tensioning means for delivering yarn from said yarn carrier to the knitting means of a knitting machine, illustrating certain critical dimensional relationships between the elements of the yarn carrier and its disposition relative to the tensioning means for controlling the lively characteristic of the twisted yarn during such delivery;

Fig. 8 is an elevational view partly in cross section of a cylindrical tube type of yarn carrier and yarn delivery means, also illustrating said critical relationships for controlling the lively characteristic of the twisted yarn'during delivery; I

Fig. 9 is a view similar to Fig. 3, showing a cone type of yarn carrier;

Fig. 10 is an elevational view of a yarn carrier similar to that of Fig. 8, but showing additional 'means for con-' trolling a very wild yarn during delivery;

Fig. ll is an enlarged, fragmentary, elevational view of thebottom portion of the cylindrical tube and associated draw cap of Fig. 8, showing in full line the position of the yarn during periods of delivery and in dot-anddash line the position of the yarn during periods of relaxation at the end of a delivery stroke;

Fig. 12 is a cross-sectional view of a modified form of draw cap adapted to be mounted on the bottom of yarn carriers such as shown in Figures 1, 3, and 7-11; and

Fig. 13 is a table setting forth illustrative sets of dimensions, within critical ranges, for the alphabetical legends applied to the various elements of the yarn carrier and tensioning means of Figs. 7 through 10.

Referring now to the drawings, it will be noted that the two yarn spools 10 and 11, shown in Figs. 1 and 3, are counterparts of each other and are associated in a twin arrangement for delivery of the oppositely twisted yarns 15 and 16 from each of these spools to a knitting machine (not shown) below. Each spool includes a core or barrel 2 upon which the yarn is wound, 'and has flanges 4 and 6 at the opposite ends thereof. These oppositely twisted yarns, when used for knitting of ladies full-fashioned nylon hose, are fed separately to'two yarn feeders on the knitting machine such that the yarns can be knitted in alternating courses to provide a balanced stretchable knitted-fabric, as disclosed in our copending application Serial No. 447,600, filed August 3, 1954.

As indicated by the arrows in Figs. 1 and 3, the yarn wound on the spool in Fig. 1 has been twisted in a left or counterclockwise direction, whereas the yarn wound on spool 11 has been twisted in a right or clockwise direction. We have found it important in delivering these yarns to the knitting machine free of snarls or kinks to deliver or unwind the yarns in the direction opposite to that in which they have been previously twisted, and this is indicated by the-arrows shown'in the bottom end views in Figs. 2 and 4. If the yarn is attempted to be unwound from the spool in the same direction in which it was previously twisted, substantial snarling or kinking of the yarn is encountered thereby rendering the knitting operation difficult and producing defects in the knitted fabric. These difficulties are avoided by unwinding the yarn from each spool in a direction opposite to its final twist as described above.

For further ease of delivery of the yarn from the spools and to prevent snagging or breaking of the yarn, the bottom flange 6 or delivery end of each spool is covered with a suitable smooth surface draw cap shown at 12 and 13 in Figs. 2 and 4, respectively. These caps are re cessed to receive the spool flanges 6. This draw cap, which is also shown at 14in Fig. 5, may be madeof any suitable smoothsurface material and we have found that a hard rigid molded resin draw cap will provide a smooth snag-free surface for delivery of the yarn. Theperiphery of the draw cap 12 is in the form of a ridge defined by

beveled surfaces

12 and 12? converging at a smooth edge 12, which is located about midway of the thickness of said draw cap. As is shown in Fig. 11 by corresponding surface 66, the surface 12 of the draw cap 13 is slanted about 37 degrees from the vertical and the surface 12 is slanted about 40 degrees from the vertical. The edge of the draw cap 13 is similarly formed with slanted

surfaces

13, 13 and an edge 13. Resin caps appear to provide more frictional resistance to yarn passing over the edge of the cap than do metallic caps, and. for this reason, are more effective in preventing snarls in the yarn. The edges'12 and 13 remain free of foreign matter, such as dust or finish material applied to the yarn. and thus offer uniform'resistance to the yarn as it unwinds in engagement with and travels around their circumference. Molded resins of the phenolic type, such as Bakelite," have been found very satisfactory for the draw caps 12 and 13. Resins of other types, however. may also be employed. For example, methylmeth-' acrylate resins, such as Lucite or Plexiglas may be used.

In addition to unwinding of the yarn in the direction opposite to which-it has been twisted and providing a smooth contact surface at the bottom of the yarn spool, as described above, it is also advantageous to stress the yarn slightly as it is being unwound; This is accomplished, at least in part, by training the yarn ends 15 and 16 over and around the

edges

12 and 13 of the draw caps 12 and 13, respectively, shown in Figs. 1 and 3. it has further been found that, for satisfactory control of the twisted yarn, certain critical relationships between the relative diameters of the empty'and fully wound yarn carrier and the diameter of the draw cap must be established. and further that the disposition and distance of the draw cap from the first delivery eyelet of the tensioning means is of importance. These critical relationships will be more fully described hereinafter in connection with Figs. 7-13.

The mounting arrangement for the yarn spools above the knitting machine, as indicated in Figs. 1 and 3, comprises an angle iron hanger 17 and a short shaft or key 18 shown connected in Figs. 1 and 3, and separated in Fig. 6. The shaft 18 has a boss or'an enlargement 19 at the top end for engaging the slot 20 in the bracket 17. The other end of the. shaft 18 has'a key 21 which is pivotally mounted at point 22 so that it can be disposed in alignment with the shaft 18 to be inserted in the bore 24 of the bobbin. After insertion in the bobbin, as in; dicated inFigs. l and 3, the key 21 may then be oriented so that it is positioned at right angles to the shaft 18 and thereby forms a suspension point for the draw cap 12 as well as.;the entire yarn bobbin.

As a further aid in handling of the yarn during the knitting operation, that is, to overcome temporarily the wildnessof the yarn so that it will not snarl or distort in passing from the yarn supply spool to the knitting machine, we have found that the yarn may 'be treated with a thin oil or oily liquid. This treatment may be carried out by immersing the spools of wound yarn, such as illustrated in Figs. 1 and 3 in the accompanying drawing, so that the thin oily liquid will penetrate the supply of wound yarn on the spool. After a thorough soaking of the spools in this manner, for example for about thirty minutes, they are then removed from the liquid bath and the excess liquid permitted to drain off.

This treatment of the yarn with the oily liquid does not adversely affect the desired lively or wildness char- 7 acteristic of the yarn, and, in fact, has no permanent efdistillate product having a viscosity (S. U. V. at 100 F.)

of 33.7 and containing a small percentage of wax or degras dissolved in the liquid.

Fig. 7 shows a spool 25, identical to the

spools

12 and 13 of Figs. 1 and 3, respectively, associated with means for controlling the twisted yarn during delivery to the knitting machine. The spool 25, of the type commonly known in the art as a take up shaft," has a core or barrel 26 and top and bottom yarn-retaining flanges 27 and 28, respectively. The bottom flange 28 is provided with a draw cap 29, which is identical to the draw caps 12 and 13 and is recessed as at 30 to snugly receive flange 28 therein, Key 21 holds the draw cap 29 in place and suspends the spool and draw cap assembly on the shaft 18 in the manner previously described. The outside core diameter of the empty spool is designated as A and the maximum diameter of the full yarn spool is designated as C. The draw cap diameter is designated as B."

' These dimensions must be within certaincritical limits to prevent snarling of the wild yarn as will be described hereinafter.

For delivery of the yarn from the spool 25 to the knitting means, a strand of yarn 31 is drawn from the spool 25 across the apex 32 of the beveled edge of the draw cap, and downwardly through a first delivery eyelet 33, which is positioned directly below the spool 25 and has its leading face in line with the axis of shaft 18. Such disposition of the eyelet 33 is important in order to assure that said eyelet is a constant distance from any point on the edge 32 over which the yarn passes. Thus, a uniform unwinding pull is applied to the yarn, with the yarn as it unwinds describing a cone having a base at the edge 32 of the draw cap of a diameter B and an apex at the face of eyelet 33, the distance between the base and apex being the dimension D. The vertical distance D from the edge 32 of draw cap 29 to the axis of the first eyelet 33 is a further critical factor for preventing snarling of the wild yarn, as will be discussed more fully hereinafter.

Eyelet 33 is supported in a conventional manner by a bracket 34 which also supports a second eyelet 35 from which the yarn 31 is drawn to a lubricating device 36. This device may be in the form of a jar or tube containing a suitable yarn lubricant 37, and having a wick 38 positioned therein. The wick 38 may be made of nyloncovered felt. The yarn 31 passes through an eyelet 39, across the top of the wick 38 where it picks up lubricant, and outwardly from eyelet 40 to a doubletensioning device 41.

Tensioning device 41 comprises a bracket 42 supported in a conventional manner (not shown) and provided with a plurality of axially aligned eyelets 43, 44, and 45, through which the yarn is drawn. Bracket 42is provided between eyelets 43 and 44 with a first guide wire 46 having a tensioning ring 47 slidably mounted thereOn and between eyelets 44 and 45 with a second guide wire 48 having a tensioning ring 49 slidably mounted thereon. The yarn 31 passes through the first eyelet 43, through tensioning ring 47, through second eyelet 44, then through the second tensioning ring 49, and thence through delivery eyelet 45 to the knitting means (not shown) of the knitting machine. The various eyelets for the delivery assembly are preferably of a material exerting minimum friction upon the yarn, smooth surfaced ceramic material generally being satisfactory. The tensioning ring 47 pri marily takes up slack between eyelet 44 and draw cap 29 and the tensioning ring 49 primarily takes up slack between eyelet 44 and the knitting means and maintains the yarn slightly taut at all times. This not only helps control snarling but also produces better selvages at the edge of the fabric by preventing the formation of loose loops. The first ring 47 may be lighter in weight than the second ring 49; for example. using a denier yarn,

the weight of the ring 47 may be 0.2896 gram and the weight of the larger ring 49 may be 0.4606 gram. These weights may vary, depending upon the denier of the yarn being delivered to the carrier. with a lighter denier requiring lighter rings. In general. the tension applied should be kept at a minimum with just enough to restrain the yarn 3| from snarling.

It has been found that the diameter B" of the draw cap should be approximately twice the diameter A of the barrel 26 of the supply carrier or spool 25, and that the outer diameter C" of the yarn on a full spool should not exceed approximately three quarters /4) of the outside diameter of the draw cap. Expressed in a different manner. the diameter C of the full spool should not exceed approximately one and one half times the diameter A" of the empty spool while the diameter B of the draw cap should be approximately'twice the diameter of the empty spool. In general, a ratio of A to B in the range from 1:19 to 1:2.25 and of A to C in the range from 1:1 to 1:15 has been found desirable. A suitable set of values within these ranges is shown in the table of Fig. l3. For example, using a standard four inch take-up shaft or spool having a barrel diameter of 2% inches, the draw cap diameter B" should be about 4% inches and the maximum diameter C of the full spool should be about 3.375 inches. The draw cap diameter may be of slightly smaller dimension, as for example 4% inches. but the maximum safe dimension of the full spool should be reduced correspondingly. A full spool diameter C of about 3 inches is preferable with a spool of barrel diameter A" of 2% inches and draw cap diameter 8" of 4% inches. It has been discovered that with a diameter C" of about 3% inches or over for the full spool with a cap diameter of 4% inches, snarling of the yarn almost immediately results. thus indicating that the size of the yarn body is too large relative to the draw cap diameter. The draw cap diameter B may be slightly increased to about A; inch above 4 inches for a spool of empty diameter A of 2 /4 inches.'but any substantial increase results in danger of the yarn pressing off or breaking before the yarn has all been taken off the spool, thus indicating that the diameter of the spool barrel is too small relative to that of the draw cap.

It has also been found that the distance D" of the draw cap 29, Fig. 7, from the first eyelet 33 should be within predetermined limits, and preferably is from about 7 inches to about 7% inches for a draw cap having a diameter of 4% inches to 4% inches. Any substantial variation from these dimensions results in kinks and snarls forming in the yarn.

It will be noted from Fig. 7 that the angle of take-off of the yarn from the top of the full spool is about 8'', whereas the angle of take-off from the top of the spool when almost completely empty is about 11". In this embodiment, the angle of draw-off at the bottom of the spool is about 90 in all instances. Thus, the minimum angle of the yarn take-off is about 8 and'the maximum is about 90". 'It will be understood that spools or carriers with a Z-twist yarn must 'be placed on the draw cap and upon the suspending shaft 18 so that the yarn is delivered over the cap in a clockwise direction before entering eyelet 33 of a tensioning device, whereas spools with an S-twist yarn are placed in the assembly to deliver the yarn'in a counterclockwise direction before entering eyelet 33 of another tensioning device, i. e. in each instance the'spools are mounted to unwind oppo sitely to the direction of yarn twist as previously described in connection with Figs. 1 to 4. p

In Fig. 8, a modification is shown wherein a cylindrical tube 50 having no retaining flanges is utilized as a yarn carrier in placeof the double-end spool shown in Figs. 1, 3, and 7. These tubes may be either of the disposable or reusable type. In this instance, the lower end of the tube 50 fits snugly within a recess 51 of a draw cap 52 especially designed to accommodate such tubes. Key 21 suspends the assembly from the shaft 13 in the same manner as with the double-end spool. The yarn 31 is wound on the tube 50 so that it is spaced slightly from the ends thereof, and may slightly taper as at 53 and 54 up to the full diameter 0" of the fully filled tube. The dimensions A," B," and C" are also found to be critical in controlling the delivery of yarn from tubes of this type without snarling or breaking. The diameter A of the empty tube again should be about one-half. of the diameter B of the draw-off cap, and the diameter C of the full tube should be about three-quarters of the diameters B, the same ranges for A28 and A:C as previously set forth being generally applicable. paper tube having a diameter A of 2.0625 inches a draw-off cap is provided which has a diameter B of 4.125 inches and the tube is preferably filled to a maximum diameter C of 3.125 inches. It will be.noted that the angle of delivery of the yarn from the full tube varies from 6 at the top to 27- at the bottom, whereas the angle of delivery from the approximately empty tube will vary from about 11 at the top to about 77' at the bottom, with the minimum angle of delivery being 6..

As in the preceding instance, utilizing a flanged carrier spool, the distance D from the draw cap 52 to the first delivery eyelet 33 is also of importance and should be within predetermined limits. With a draw cap of a dis ameter of 4.125 inches, the distance *D" is preferably about 8 inches and should not exceed about 8% inches.

In Fig. 9 is illustrated a still further type of yarn carrier. Herethe yarn carrier comprises a frusto-eonical shaped tube 56 of a type commonly known as a "jumbo cone. The lower or large end of the conical tube is provided with a draw cap 57 which has a recessed portion 58 in which the lower part of the conical tube is snugly received. The conical tube 56 has an arithmetic mean diameter A which is preferably about one-half of the diameter B of the draw cap. For example, with a 6% inch jumbo cone having a mean diameter A of stantially greater dimensions than that specified will re when approximately two-thirds of the yarn has been run off. On the other hand, ifthe tube is filled to a maximum dimension greater than that specified for .C, the result is almost immediate snarling and kinking of the yarn during the beginning-of a delivery period. Forexample, with a 4% inch draw cap snarling begins when the maximum filled tube diameter approaches 3% inches. The dimension D in this case also should be within predetermined limits and is preferably about 8 inches for a 4% inch draw cap, with a maximum not in excess of 8% inches. a

It will be noted from Fig. 9 that the angle of draw-off from the full tube varies between 7 51 to 17 for the filled tube, and between 9 51' and 51' for the nearly For example, with a standard 6% inch 9 empty tube. the minimum angle of draw-off being about 8.

Fig. l illustrates a still further modification of the invention wherein a plurality of drawoff caps may be utilized to provide control of the delivery of a very wild yarn. A yarn carrier 60 which may be a paper tube of the type shown in Fig. 8. fits snugly in a recess 61 of a first draw cap 62. which in turn is supported by a spacer tube 63 which fits snugly in a recess 64 of a second draw cup 65. Key 21 in this instance holds the entire assembly to the shaft 18 in the same manner as previously described. In this instance the same critical relationship for A." B. "C" and D" holds true as has been previously described. The distance D" in this case, however. is measured from the rim of the bottom cap 65 to the first delivery eyelet. For a 6% inch paper tube having a diameter A" of 2.0625 inches and a draw cap diameter 8" of 4.125 inches, the space between the plural caps may be one inch and the distance D from the bottom cap rim to the first eyelet 7 to 8 inches. The second or bottom draw cap 65 may be identical to the first or top draw cap 62 as illustrated. or may be slightly smaller in diameter. For example. with a first draw cap of 4.125 inches the second draw cap may be 3.875 inches. While only two draw-off caps are shown, it will he understood that a greater number may be utilized if so desired. However. the yarn must touch the rim of each cap for the control to be effective.

Fig. It shows a preferred form of draw cap and the manner in which the yarn contacts the draw cap during periods of delivery and periods of relaxation such as occur at the end of a delivery stroke of a knitting machine. Thus, the edge of the draw cap 29 is provided with a beveled upper face 66 and a beveled lower face 67 forming annular apex 32 which is in contact with the yarn 31 during delivery as shown by the full line on the drawing. The yarn 31 has a minimum or substantially point contact with draw cap 29 while the yarn is being knitted. The beveled upper face 66 permits the yarn to relax without snarling at the end of a delivery stroke. The position of the relaxed yarn is shown by the dotdash line 68. An angle of bevel of about 37 from the vertical has been found satisfactory to provide adequate control of the yarn at all positions normally encountered. It will be noted the upper beveled face 66 is narrower than the lower beveled face 67. This provides a minimum yarn contact surface to collect foreign matter which might interfere with the yarn control.

It will be understood. however. that modified configurations of draw cap edges may be employed without departing from the scope of the invention. Thus, a draw cap 69. as shown in Fig. l2, having a single.beveled face 70. may in some instances be used, as, for example, in draw caps of. relatively small diameter. It should be noted that the bevel 70 is slanted in a direction enabling control of the yarn during relaxed periods.

The winding of the yarn upon a spool having a cylindrical core. or upon a cylindrical tube enables the winding to be done upon conventional winding apparatus, and the direction of twist can be indicated by winding 8 twist yarn upon tubes of one color and Z twist yarn upon tubes of a differentcolor. A mark or label can be attached to one end of the spool or tube to guide the knitter in properly mounting it upon the shaft 18 so that it will unwind in the correct direction. Conical tubes aid the knitter in proper mounting. but special equipment is required to wind the Z twist yarn in an opposite direction to S twist yarn. Hence, cylindrical tubes are preferred.

it will be understood that the above-described mechanical arrangement and also the liquid treating of the yarn are not limited to any particular type of twisted yarns and may be used generally where a lively or wildness characteristic of the yarn needs to be controlled during the knitting operation. The twisted yarn may. as above suggested, be used in the knitting of ladies sheer hosiery, either full-fashioned or seamless types, or in the production of other knitted fabrics. Similarly. while nylon yarn is the presently preferred commercial form of yarn best suited for this purpose, other types of synthetic yarn, such as Arnel, Dacron and Orlon," which are adaptable for handling in accordance with the present invention may be used.

Technical identification of these four yarns are as follows:

Arnel-cellulose triacetate.

Nylona group of thermoplastic linear long-chain superpolyamides.

Dacrona condensation polymer of terephthalic acid and ethylene glycol.

Orlon-acrylonitrile polymer, usually combined with other substances.

The term draw cap referred to in the specification and claims herein is intended to include the type of cap or end cap commonly known in the trade as a draw-off cap.

This application is a continuation in part of our copending application Serial No. 463,274, filed on October 19, 1954.

Various modifications and changes may be made in the above-described processes, apparatus, materials and conditions without departing from the scope of our invention as defined in the appended claims.

We claim:

1. A method of controlling'the wildness of twisted synthetic yarn during delivery of the yarn to a knitting operation, comprising: winding the twisted yarn on a yarn carrier to a fullness not substantially in excess of about one and one-half times the mean. diameter of the empty yarn carrier, and unwinding the yarn from said yarn carrier by training said yarn over and around a contact surface spaced laterally from the axis of said carrier at one end thereof so that the yarn as continuously withdrawn over said contact surface describes a circle concentric with the axis of said yarn carrier and said contact surface having a diameter of approximately twice the mean diameter of said yarn carrier when empty.

2. A method of controlling the wildness of twisted synthetic yarn, as defined in claim 1, in which the yarn is withdrawn over and around a contact surface having a diameter in the range of from 1.9 to 2.25 times the mean diameter of the empty yarn carrier and in which the yarn carrier is wound to a fullness not exceeding three-quarters of the diameter of said contact surface, and further in which the yarn is withdrawn to a point substantially in line with the axis of said yarn carrier and vertically spaced from said contact surface a predetermined distance.

3. A method of controlling the wildness of twisted synthetic yarn as defined in claim 2 and in which the yarn is withdrawn from the carrier in a direction opposite to the direction of twist of the yarn.

4. A method of controlling the wildness of twisted synthetic yarn as defined in claim 1 and in which the contact surface is the periphery of a draw cap.

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