US2822605A - Manufacture of pile yarn and of pile carpet made therefrom - Google Patents

Description

Feb. 11, 1958 D. B. PARLIN MANUFACTURE oF PILE YARN AND oF PILE CARPET MADE THEREFROM 4 Shee'cs-Sheei'l 1 Filed Jan. 26, 1953 Feb. 11, 1958 D. B. PARLIN MANUFACTURE 0E PILE YARN AND 0F PILE CARPET MADE TEEREEROM 4 Sheets-Sheet 2 Feb. 11, 1958 D. B. PARLIN MANUFACTURE OF' PILE YARN AND OF PILE CARPET MADE THEREFROM Filed Jan. 26, 1953 4 Sheets-Sheet 3 Invezov.-

Feb. 11, 1958 D. B. PARLIN 2,822,605

MANUFACTURE OF PILE YARN AND OF PILE CARPET MADE THEREFROM 4 Sheets-Sheet 4 Filed Jan. 26, 1953 nited States Patent O MANUFACTURE F PILE YARN AND OF PILE CARPET MADE THEREFROM vDavid B. Parlin, Thompsonville, Conn., assigner to Bigelow-Sanford Carpet Company, Inc., Thompsonville, Conn., a corporation of Delaware The present invention relates to improvements in the manufacture of pile yarns, and in the manufacture of pile carpet from said yarn.

It is a principal object of the invention to produce a novel pile yarn having novel and improved color and wear characteristics for use in the manufacture of pile surface floor coverings or carpets.

More specifically, it is an object of the invention to provide, for use in the manufacture of loop pile surface floor coverings, a pile yarn composed of a plurality of strands which are enchained with one another to form a composite pile yarn of a novel constructionv which is resistant to catching or pulling and which has novel and readily variable color characteristics.

It is a further object of the invention to provide a novel and improved floor covering of the general type having a backing material and a pile surface of looped pile yarn which is novel in construction, distinctive in appearance, and possessed of improved covering and wearing qualities,

In accordance with the invention a novel multi-colored yarn is provided which is formed of a plurality of strands enchained together by means of a stitching operation. The operation may be carried out upon an overedge stitcher provided with a chain forming mandrel. The composite pile yarn is formed preferably with long stitches which are tied together by a series of tightly drawn loops produced by causing a heavy tension strain to be applied against some one of the feeding strands. The pile yarn produced in this manner has certain outstanding characteristics not found in knitted yarn or in warp knitted tape constructions. The enchained yarn here illustrated is so integrated and so rmly bound as to be resistant to catching or pulling, has no tendency to unravel even though any one of the strands may be broken, and further provides for an arrangement of the strands in the completed yarn which produces unexpected and striking color effects. Variation of the tension applied to the individual strands has been found to produce substantial changes in the proportion of one strand to another in the enchained yarn with a corresponding contrast in the general color effect where two or more strands of different color are employed.

The novel pile yarn herein described is tufted, woven or otherwise combined with suitable backing material and has been found particularly adaptable for this use to form a loop pile surfaced floor covering of superior quality and appearance. The spaced strictures formed by the tightly drawn loops of the more heavily tensioned strand of the yarn, produce a characteristic resiliency and tendency to retain its position and shape even where relatively soft pile yarns are employed, and impart to the pile loop surface a degree of toughness and resistance to wear much greater than that found in the floor coverings of the prior art. The frequent tying-in of the several strands along the length of the yarn effectively over- Patented Feb. 11, 1958 comes any tendency of the strands to be caught or pulled out under conditions of actual use.

The pile yarn formed in accordance with the present invention, especially where two or more different colors of strands are employed, imparts a unique appearance to the-loop pile surface of the floor covering which is both distinctive and pleasing. Further variations in appearance of the finished fabric are produced by shifts in the proportions of the different colored strands in the yarn produced by the tensioning of first one and then the other of the individual strands fed to the stitching mechanism for enchaining in a single pile yarn.

Further, in accordance with the invention, the enchained yarn is produced on an overedge type stitcher having the conventional stitch-forming instrumentalities, including a needle and over and under loopers, in accordance with a novel method which comprises forming a series of enchained loops from either two or three feeding strands about a forming mandrel, selectively increasing the tension applied to one or another of the feeding strands, and drawing off the chain formed by the stitchforming instrumentalities at a rate which is related to the rate of operation of the stitch-forming instrumentalities, and which thereby controls the number of stitches per inch of the enchained yarn. f

With the above and other objects in view which may hereinafter appear, the several features of the invention consist also in the devices, combinations, arrangement of parts and in the method above described which together with the advantages to be obtained thereby will be readily understood by one skilled in the art from the following description taken in connection with the accompanying vdrawings in which:

Fig. lis a diagrammatic opened-out Vview of` aneuchained two-strand pile yarn produced in accordance with the present invention and further'illustrating the change in yarn structure produced by the transfer of a relatively heavy tensioning strain from one to another strand; Y

Fig. 1a is a diagramatic opened-out view o f an enchained two-strand pile yarn similar to that shown'in Fig. l, but with the addition of a core yarn;

Fig. 2 is a somewhat diagrammatic opened-out view of an enchained three-strand pile yarn produced in accordance with the present invention and further illustrating the change in yarn structure produced by the transfer of a relatively heavy tensioning strain from one to an-v other ofsaid strands;

Fig. 2a is a diagrammatic opened-out view of a threestrand yarn similar to that illustrated in Fig. 2, but with the addition of a core yarn; Y

Fig. 3 is a photographic plan view of a section of a floor lcovering produced in accordance withthe invention; f

Fig. 4 is an isometric view of an overedge stitcher adapted for the forming of the enchained yarns of Figs. 1 and 2, the machine being shown in operation for the forming of a two strand yarn such asthat shown in Fig.' l;

Fig. 5 is a rear elevationv of the machine shown in Fig. 4 illustrating particularly the tensioning device for applying a heavy tension selectively to one oftwo feeding yarns, the tension control solenoids, theelectrical timing unit for controlling the operation of the solenoidsfand the auxiliary yarn draw-off unit connected to be ldriven in timed relation with the operation of the stitcher; an'd Fig. 6 is a somewhat diagrammatic sectional view of a floor covering including the backing material and a serie of pile loops of the yarn shown in Fig. 1. v f

Referring to the drawings, Fig. 1 illustrates diagram--r matically, and withthe loops loosely 4 intermesh'ed for purposes `of illustration, a two-strand enchained pile Vescasos yarn made in accordance with the invention having novel and improved characteristics which adapt the yarn especially for use in the manufacture of loop pile fabrics. The yarn `shown in Fig. 1 consists of two strands, a white strand and a black strand 12, which are formed into a series of loops of which each loop of one strand is enchained with a next succeeding ioop of the other strand. The white strand 10 in the left hand portion of Fig. 1 is formed into relatively small tight loops 14 which appear at spaced intervals along the length of the yarn. The black strand 12 is drawn into long loosely formed loops 16 which lie in a direction generally inclined toward the axis of the yarn. The stitches, each of which consists of one loop of the white strand 10 and one loop of the black strand 12 enchained therewith are preferably of a length to form from three to six st itchesper inch, although a greater variation, as for example from two to seven stitches per inch, is permissible if desired, depending upon the material used. In appearance, the yarn is constricted at the location of each tight loop 14 but tends to lie loosely between the loops 14 imparting an appearance of looseness to the yarn as a whole. lt will be noted from an inspection of the left portion of Fig. 1 that there are, between succeeding tight loops 14, three connecting links of the black strand .and one connecting link of the white strand. This portion of the yarn formed with the tightly tensioned white strand 10 and the loosely tensioned black strand-12 is predominately black in color but with white streaks formed therein as shown, for example, in the dark areas of Fig. 3.

As hereinafter more fully set forth, the peculiar loop structure shown in the left hand portion of Fig'l is produced on an overedge stitcher having a needle, an upper looper, a lower looper, a mandrel about which successive stitches are formed, and a draw-off device by means ofwhich the completed yarn is drawn-oit at a rate determined in accordance with the number of stitches called for per inch.

Passing from the left to the right hand portion of Fig. 1 the tension uponY the feeding white strand 10 has been reduced and a heavy tension is now automatically applied to the feeding -black strand 12, so that the black strand is caused to form tight loops 18 spaced a stitch length apart along theV yarn. The loops 1S are connected by a loop 20 and an additional connecting link of the white strand extending in a direction substantially lengthwise of the completed yarn so that between succeeding tight loops 18 there are provided three connecting links of the white strand and one connecting link of the black strand, thus giving the portion of the yarn shown in the right hand portion of Fig. 1 a predominately white color, but streaked with black, as shown in the light areas of Fig. 3.

As previously pointed out, Fig. l is a somewhat diagrammatic disclosure of applicants novel enchained yarn. An artists representation of the two-strand yarn shown in Fig. Yl with the white strand predominating, is shown in'Fig. 4, anda photographic representation of the twostrand black and white yarn as embodied in a door coveringrhaving a looped pile surface is shown in Fig. 3.

n Theenchained yarn formed in the manner above described has been found to have a number of unusual and useful characteristics which adapt the yarnY particularly for use as a pile yarn in a loop pile fabric. The strands are very .firmly secured together at intervals by the tightly drawn loops of the one strand while at the same time a loose flowing appearance of the pile surface loops is provided by the relatively long connecting links extending between the successive tightly drawn loops of the one strand. The structure of the 'enchained `yarn is such that breakagerof any one of the strands at any point will have no serious effect upon adjacent portions of the yarn,

as there is no tendency of a severed strand to pull or ravel.

The physical structure of the yarn has made it possible to employ materials which would not ordinarily be considered adaptable for use in the manufacture of a loop pile fabric, for example a synthetic fiber such as filament rayon, which is both smooth and slippery and tends to be caught and Vpulled during actual use. A continuous filament synthetic liber when incorporated into applicants enchained yarn structure is tied together so rmly, iirst by the enchaining of the strands and further by the insertion of the tightly drawn loop in each successively formed stitch, as to substantially eliminate the objections above noted, while at the same time the relatively loose arrangement of the strand links between the tightly drawn loops in the yarn imparts a relatively sott and nely bered appearance to the looped pile surface of the fabric.

A further novel characteristic of the improved pile yarn structure shown, which is of particular advantage for use as a pile yarn in the manufacture of lloor coverings having a loop pile surface, consists in the highly resilient, non-crushable quality of the looped yarn which when released tends quickly to return to its initial position.

Fig. 2 is a disclosure of a three-strand enchained yarn, each strand being formed into a series of loops of which each successive loop is enchained with the next succeeding loop of an adjacent strand in rotation. For convenience of illustration, strands of three different colors are shown including a white strand 24, a black strand 26 and a third strand 28 which may be either the same or a different color from either of the other strands. In the left hand portion of Fig. 2, the yarn is enchained together or stitched under conditions in which a relatively heavy tension is applied to the white strand 24 and a relatively light tension is applied to the darker strands 26'and 23. The loops 30 of the white strand 24 are thus drawn in tightly-whereas the loops 32, 34 formed from both of the other strands and subiected to a normally light tension, lie in a generally parallel relation lengthwise of the completed yarn. The right hand portion of Fig. 2 illustrates a condition in which the heavy tension or resistance applied to the white strand 24 has now been transferred to the dark colored strand 26 causing loops 35 formed from the strand 26 to be drawn in tightly, and causing loops 3S, 4t) formed from strands 24 and 23, to be formed loosely.

The three-strand yarn of Fig. 2 has substantially the advantages of the two-strand yarn shown in Fig. 1 in that the colored strand to which heavy tension is applied is subordinated, permitting the remaining strand color or colors to become predominant. The enchaining process and the drawing in of the loops made from one strand combine to produce a stable resilient pile yarn, and one in which increased bulkiness is imparted to the yarn.

, it will be observed that in the two-strand yarn of Fig. l

the legs of the successively formed loops provide the equivalent of four strands, and in the three-strand yarn of Fig. 2 the legs of the successively formed' loops provide theV equivalent of tive strands. The physical structure of the yarn combined with color variation from one strand to another serves also to provide a pile yarn having unusual color and textural characteristics. The stitches formed from the three-strand yarn are preferably of a Vlength to form from'two to six stitches per Y inch. although greater variation may be permissible depending upon the material used.

Figs. la and 2a of the drawings are disclosures of twoand three-strand yarns similar toy those illustrated in Figs. l and 2, but with the addition of a heavy core yarn 22. In the formation of the yarn shown in Fig. la the strands 10,:12 are enchained around an anvil in the same manner as in the formation of the two-strand yarn illustrated in Fig. 1 hereinafter` specifically described.Y Thel core yarn is preferably fed through a hole Vformed in the center of a specially constructed anvil. The feeding of the yarn causes the enchained strands to be drawn onto and tightened about the core 22. By substantially increasing the tension on one or the other strand the same color variation along the length of the yarn is produced as in the case of the two-strand enchained yarn of Fig. l. l

The cored three-strand yarn of Fig. 2a is formed in the same manner as the three-strand enchained yarn above described and illustrated in Fig. 2, but with'the addition of the core yarn 22 which is preferably fed through a centrally located aperture in a specially constructed anvil. Variation in the tension on the feeding strands causes color variations to appear along the length of the cored yarn in the same manner as that set forth in the formation of the three-strand yarn of Fig. 2. The cored yarn has the specific advantages of greater weight, exceptional strength and resistance to stretch, which are in addition to the advantages previously noted for the three-strand enchained yarn of Fig. 2.

It will be understood that the invention in its broadest aspects is not limited specifically to the yarn structure illustrated, but it will include multiple strand enchained yarns in which the strands are distinguishable from each other by physical characteristics other than color, or in which strands having different dye absorbing characteristics are employed, the differences in color to be brought out only when the fabric woven from the yarn is linally dyed. Fig. 3 shows a sample of a tufted oor covering having a looped pile surface produced with the enchained pile yarn specifically illustrated in Figs. 1 and 4 of the drawings in accordance with the invention. It will be understood also in accordance with the invention, that pile yarns having three enchained strands as shown in Fig. 2, and core yarns having a core strand and two enchained strands as shown in Fig. laor a core strand and three enchained strands as shown in Fig. 2a, may be drawn as loops through the fabric to produce a pile tufted iloor covering in many respects similar to the tufted pile fabric shown in Fig. 3. The sample shown comprises specifically a woven backing material through which are drawn series of loops of the enchained pile yarn. t The tufting operation is carried out in a well known manner on a tufting machine which may have from one to several scores of tufting needles, each threaded with a separate pile yarn and driven in unison to pass successive groups of loops through the backing material from back to front. Loopers cooperating with the respective needles and located at the face side of the work are arranged to engage with and retain the respective pile loops as the needles are withdrawn preparatory to the formation of the next stitch.

It will be understood that a oor covering having a looped pile surface in accordance with the invention may be produced in other well known ways, as for example by a weaving operation in which the pile loops are formed from pile warps comprising the enchained pile yarns herein described which are raised over pile wires.

The floor covering produced in accordance with the invention having the loop pile surface thereof formed from applicants novel enchained pile yarn as above described has novel and desirable characteristics from the standpoint of both construction and appearance. As will readily be seen from an inspection of the photographic Fig. 3, the individual strands forming each yarn are plainly visible and impart to the loop pile surface the appearance of a finely woven fabric, while at the same time the individual loops, being tied firmly together at intervals by the tightly drawn loops of the tensioned strand, have a wholly unexpected rmness and a resiliency which 'prevents the pile surface from being crushed or matted "6 Y as a result of continuous use. The yarn, being relatively bulky and comprised of strands which tend to balloon between the successive tightly drawn tying-in loops, provides a very good coverage even though a relatively coarse gauge is employed in the spacing of the individual loops and rows of loops. v

A further outstanding characteristic of the floor `covering shown for example in Fig. 3 is the characteristic appearance which is achieved by the enchaining together of strands of two different colors which in the sample shown may be black and white. As previously noted and as hereinafter more fully set forth in connection with the method of manufacture employed, the subjecting of any one of the feeding strands tov a relatively heavy tension has the effect of causing the other less heavily tensioned strands to appear predominately in the completed yarn. In the disclosure of Figs. 1, 3 and 4 each enchained pile yarn is made up of a black and a-white strand, of which one strand is tensioned during the stitching or enchaining of a predetermined arbitrary length of the enchained pile yarn, and thereafter the other strand is similarly subjected to a heavy tension during the stitching or enchaining of a'further arbitrary length of the enchained pile yarn, so that in the tufting operation a series of pile loops are formed in which rst one and then the other color predominates to produce the scatter pattern effect shown in Fig. 3. A further-outstanding characteristic of the pile surface formed with applicants improved yarn consists in the peculiar mixture of colors produced by the enchaining process whereby the areas predominantly white in color show also traces of black throughout the area, and the areas predominantly black in color similarly show traces of white. A unique texture and gradation of color from light to dark in the looped pile surface is thus obtained which is both soft and pleasing.

The improved pile yarn above described is produced by a novel and improved method of enchaining together the individual differently colored strands. The enchained yarn is preferably produced on a conventional overedge stitcher of the general type having a curved strand-carrying needle and an upper looper and a lower looper, each apertured to receive a feeding strand. For the making of two-strand yarn the lower looper only' is formed as a strand carrying looper. The stitch forming mechanism described, when operated without work Vin the machine forms a thread chain in which a loop -of one strand is drawn through a loop of another strand which is in turn drawn through a new loop of the first strand, or through a loop of the third strand if three strands are used, in continuous rotation. Inasmuch as stitchers of' the general type referred to, including a curved needle and upper and lower loopers, are well known in'the art, specific illustration or description of this mechanism is believed unnecessary. For a more' complete description of a machine of the general type illustrated reference may be had to the patents to Steadman No. 733,760 and Washburn 1,966,367.

It will be understood that the illustrated machine differs from those shown in the prior art specifically in the omission of the usual work table, feed dog and presser foot mechanisms adapted for supporting and feeding work in the machine.

Referring specifically to Figs. 4 and v5 of the drawings, an overedge stitcher of the general type referred to is shown comprising a base 42 and a housing 44 within which are mounted the supporting and actuating mechanisms not shown. The machine is provided with a curved eye needle 46, an upper looper 48 and a lower looper 50. The needle 46 is mounted on a rocker arm A52 arranged to oscillate about a pivotal support not specifically shown. In place of the usual work support and feed dog the illustrated machine is provided with a chainforming mandrel 54. '.As best shownin Fig..4',-the mandrelw54takes the form of a horizontally disposed member having a't'apered'end portion extending generally in the direction of feed wwithl relation to the stitching devices. The mandrel 54 is adjustably secured by a clamping screw 56 in a guideway S8 on a bracket 60 carried on the base 42. The tapered end of the anvil member 54 is located with relation to the stitch forming devices so that the needle, moving forwardly and downwardly, passes across the front face of the mandrel 54, the lower looper passes transversely beneath the mandrel 54, and the upper looper moves in a generally vertical direction across the rear face of the mandrel S4. The machine is shown as set up for theforming of a two-strand enchained yarn. The strand 12 is threaded through the eye of the needle 46. Thestrand is threaded through an eye in the lower looper S0.

In accordance with the present invention a novel tensioning mechanism is provided for applying a relatively heavy` tensionY selectively to one or the other of the two feeding strands. The strand 12 threaded through the needle `46 may correspond with the black strand 12 of Fig. l and the strand threaded through the lower looper 50 may be taken as the white strand 10 of Fig. l. The

two strands as shown in Figs. 4 and 5 are drawn from supply through individual solenoid controlled tension devices mounted in an open housing 70 on a frame 72 carried by the base 42, through the usual tensioning devices designated respectively at 74, 76 on top of the machine, and thence through guides and take-up devices which may be of ordinary construction to the needle 46 and lower looper 50 respectively.

The solenoid controlled tension devices provided in accordance with the invention comprise specically two xed friction disks 78 and 80 which cooperate respectively with two movable tension disks 82 and 84. For moving the tension disks 82, 84 into and out of operative position, solenoids 86 Vand 88 are mounted on the skeleton housing 70 with armature shafts 90, 92 which are connected respectively to moveable disks 82, 84.

The solenoids 86, 88 are caused to operate alternately so that one of the friction disks 82, 84 is moved to an inoperative position while the other of said disks is released to engage with and apply a heavy tensioning strain to its feeding strand. The lirst solenoid is then deenergized and the second solenoid is energized to cause a heavy tensioning strain to be applied to the first strand, and to release the tension on the ground strand. The operation of the solenoids is controlled by an electrical timing device which may be of ordinary description and which leads into a switch secured to the top of the frame 70. The timing device is set to cause each solenoid in turn to be energized for a predetermined length of time. Assuming a rate of operation ofthe machine at 4500 revolutions per minute, an adjustment of the variable yarn draw-off mechanism 120, hereinafter referred to, to produce approximately 4 stitches per inch of yarn, and the length of yarn in which one color predo'minates to be Y between 40 and 50 inches, the time interval between successive operations of the timing device, when each solenoid isv again energized or de-energized, will be in the neighborhood of 21/2 seconds.

As shown in Figs. 5 and 4, the strand 12 drawn from supply passes through a guide 96, between disks 84, 80 of the solenoid controlled tension device, thence through a guide 98 on the casing 44, through the usual tension 74 on top of the machine, through eyes 100, 182 on a stationary bracket 1.04, and through an eye 106 of an interposed take-up arm 108, and thence tothe needleV 46.

, Strand 10 drawn from supply passes through a guide 110 between the disks 78, 82 of the solenoid control tension device, through the usual tension 76 on top of the machine, and thence downwardly and upethroughV the bracket to thelowerlooper. Y

Y The. enchaitiedv yarn producedby vthe operation of, the

stitching mechanism its drawn ott between a Pair of drawoif rolls 1 16, 118 which are .positively driven at a rate related to the speed at which the stitching mechanism is driven to produce a desired number of stitches per inch. The rolls 116, 118 are mounted on output shafts of a variable speed drive unit which is generally designated at 120'in Fig. Y5 mounted on the base 42 of the machine. An input shaft 122 of the variable speed unit 120 carries a pulley 124 which is driven from a main driving belt 126 passing also around a driving pulley 128 carried on the main drive shaft 130 of the stitcher. Any desired variation in the number `of stitches per inch in the enchained yarn 132 is effected by a simple pulley change on the variable speed unit. Inasmuch as the variable speed unit is of a type well known in the art it is believed unnecessary to show this mechanism in detail. A continuous even tension is maintained on the enchained yarn 132 drawn off from the machine by the rolls 116, 118, a guide 13.4 being used to control the direction of the yarn drawn from the forming mandrel 54 by the drawotf rolls 116, 118.

The invention having been described what is claimed 1s:

l. A pile yarn comprising two strands having dierent color characteristics, each strand being formed into a series of loops, of which each loop of one strand is enchained with the next succeeding loop of the other strand forming a series of lock stitches evenly spaced along the length of the yarn, predetermined lengths of said yarn having the loops of one strand tightly formed and the loops of the other strand loosely formed to provide a substantial preponderance of the loosely looped other strand and a preponderance of the associated color charac-` teristic in Ysaid lengths of the yarn, and other lengths of said yarn having the loops of said one strand loosely formed and the loops of said other strand tightly formed to produce a substantial preponderance of 'said loosely looped one strand and a preponderance of the associated color characteristic in said other lengths of the yarn.

2. A pile yarn comprising a plurality of strands, each strand being formed into a series of loops of which each loop of each strand is enchained with a loop of another strand in rotation to form a series of lock stitches evenly spaced along the length lof the yarn, predetermined lengths of said yarn having the loops of one strand tightly formed and the loops of the other strands loosely formed to provide a substantial preponderance of said loosely looped other strands in said lengths of the yarn, and other lengths of said yarn having the loops of another strand tightly formed and the loops of the remaining strands loosely formed to obtain a substantial preponderance of said loosely looped remaining strands in said other lengths of the yarn.

3. A pile yarn comprising three strands including at least two strands with different color characteristics, each strand beingformed into a series of loops, of which each loop of each strand is enchained with the next succeeding loop of another strand in rotation to forma series of lock stitches evenly spaced along the length of the yarn, predetermined lengths of said yarn having loops of a strand with onepcolor characteristic tightly formed, and having the loops ofthe other strands loosely formed to provide at substantial preponderance of the said loosely looped other strands and a preponderance of the associated color characteristic in said lengths of the yarn, and in other4 lengths of said yarn having the loops of a strand with another color characteristic tightly formed and the loops of the remaining strands loosely formed to obtain asubstantial preponderance of said loosely looped remaining strands and a preponderance of the associated color characteristic in said other` lengths of the yarn.

4. A' pile yarn comprising a plurality of strands of ilament` syntheticy fiber includingstrands of dierent'color characteristics, eachstrand being, formed into a series of loops ofwhch each. successively farmed 1001 0f. each strand is enchained with a next succeeding loop of another strand in rotation to form a series of lock stitches evenly spaced at the rate of between two and seven stitches to the inch along the length of the yarn, predetermined lengths of said yarn having the loop of a strand with one color characteristic tightly formed, and having the loops of other strands loosely formed to provide a substantial preponderance of said loosely looped other strands in said lengths of the yarn, and other lengths of said yarn having the loops of a strand with a different color characteristic tightly formed, and having the loops of the remaining strands loosely formed to obtain a substantial preponderance of said loosely looped remaining strands in said other lengths of the yarn.

5. A pile yarn comprising a plurality of strands including a core yarn and at least two chain forming strands with different color characteristics, each chain forming strand being formed into a series of loops of which each successively formed loop of each chain forming strand is enchained with the next succeeding loop of another chain forming strand in rotation about the core yarn to form a series of lock stitches spaced evenly at a rate chosen between two stitches and seven per inch along the length of the yarn, predetermined lengths of said yarn having the loops of one strand of said two chain forming strands tightly formed and the loops of the other strands loosely formed to provide a substantial preponderance of said loosely looped other strands and a preponderance of the associated color characteristic in said lengths of the yarn, and other lengths of said yarn having the loops of the other of said two chain forming strands tightly formed, and the loops of the remaining chain forming strands loosely formed to provide a substantial preponderance of said loosely looped remaining chain forming strands and a preponderance of the associated color characteristic in said other lengths of the yarn.

6. A pile yarn comprising a core yarn and three chain forming strands including at least two strands with diierent color characteristics, each chain forming strand being formed into a series of loops of which each loop of each strand is enchained with the next succeeding loop of another strand in rotation about the core yarn to form a series of lock stitches evenly spaced along the length of the yarn at a rate chosen between two and seven stitches per inch, predetermined lengths of said yarn having loops of a strand with one color characteristic tightly formed, and having the loops of the other strands loosely formed to provide a substantial preponderance of said loosely looped other strands grouped about the core yarn and a preponderance of the associated color characteristic in said lengths of the yarn, and in other lengths of said yarn having the loops of a strand with another color characteristic tightly formed and the loops of the remaining strands loosely formed to provide a substantial preponderance of said loosely looped remaining strands grouped about the core yarn and a preponderance of the associated color characteristic in said other lengths of the yarn.

7. A oor covering comprising a 1backing material and a loop pile surface of multi-colored pile yarn comprising at least two strands with different color characteristics, each strand being formed into a series of loops of which each loop of each strand is enchained with the next succeeding loop of another strand in rotation to form a series of lock stitches evenly spaced along the length of the yarn, the yarn forming some of said pile loops having the loops of a strand with one color characteristic tightly formed and the loops of said other strands including the strand with a different color characteristic loosely formed to provide a preponderance of the loose strands and of said associated different color characteristic in certain of said pile loops, and other pile loops of said fabric having the loops of said strand with the diterent color characteristic tightly formed and the loops of the remaining strands -including the strand 10 s with said one color characteristic loosely formed to v obtain a substantial preponderance of said loosely looped remaining strands and of said associated color characteristic in said other pile yloops of the floor covering.

8. A iloor covering comprising la backing material and a loop pile surface of multi-colored yarn composed of differently colored strands, each strand being formed into a series of loops of which each loop of each strand is enchained with the next succeeding loop of another strand in rotation to form a series of lock stitches evenly spaced along the length of the yarn, lengths of said yarn forming some pile loops having the loops of one strand tightly formed and the loops of the remaining strands loosely formed, and other lengths of said yarn forming other pile loops having the loops of another of said strands tightly formed and the loops of the remaining strands loosely formed to obtain a substantial preponderance of first one and then another color Vcharacteristic in said respective lengths of yarn and in the pile loops formed therefrom.

9. A floor covering -comprising a backing material, and a loop pile surface of multi-Stranded yarn composed of a plurality of strands of continuous filament synthetic iiber, each strand being formed into a series of loops of which each loop of each strand is enchained with the next succeeding loop of another strand in rotation to form a series of lock stitches evenly spaced and numbering between two and seven to the inch along the length of the yarn, and with the loops of one strand tightly formed, and with the loops of any remaining strand loosely formed to obtain a substantial preponderance of said loosely looped other strands in said yarn, and a periodic tight binding of said strands into said yarn.

l0. A iloor covering comprising `a backing material, and a tread pile loop surface of multi-colored yarn composed of lament synthetic libers having different color characteristics, each strand being formed into a series of loops of which each loop of each strand is enchained with the next succeeding loop of another strand in rotation to form a series of lock stitches at the rate of 3 to 6 to the inch evenly spaced along the length of the yarn, lengths of said yarn forming selected pile loops having the loops of one strand tightly formed and the loops of the remaining strands loosely formed, and other lengths of said yarn forming other pile loops having the loops of -another color tightly formed and loops of the remaining strands loosely formed to obtain a substantial preponderance of iirst one, and then another color characteristic in said respective lengths of yarn and in the pile loops formed therefrom.

- ll. A oor covering comprising la backing material and a loop pile surface of multi-col-ored pile yarn comprising a plurality of strands including a core strand and at least two chain forming strands of different color characteristics, each chain forming strand being formed into a series of loops of which each loop of each chain formlng strand is enchained with the next succeeding loop of another chain forming strand in rotation about said core strand to form a series of lock stitches evenly spaced along the length of the yarn, the yarn forming some of said pile loops having the loops of one chain forming strand tightly formed and the loops of any remaining chain forming strand loosely formed to provide a substantial preponderance of said loosely looped remaining chain forming strand and of the associated color characteristic in said pile loops, Iand other pile loops of said fabric having the loops of another chain forming strand tightly formed and the loops of lany remaining chain forming strand loosely formed to obtain a substantial preponderance of said loosely looped remaining strand andY of the associated color characteristic in said other pile loops of the floor covering.

12. The method ofV forming a multi-colored pile yarn having a variable color characteristic along its length, which comprises' the steps of combining a plurality of strands including lock stitching together at least two chain forming strands of dierent color characteristics around a chain-forming mandrel, drawing oi the yarn so formed with relation to the lock stitching at a rate of at least two stitches per inch and selectively applying a heavy resistance to one only of said chain forming strands to cause said chain forming strand to form tight loops and any other chain forming strand to form elongated loosely formed loops, and shifting said heavy resistance from one to another chain forming strand in rotation to cause each of said chain forming strands in turn to form tight loops and any remaining chain forming strand to form elongated loosely formed loops, and therebyto produce a substantial preponderance of diierent chain forming strands and corresponding ydifferent color characteristics in different lengths of the said yarn.

13. The method of forming a multi-colored pile yarn having a variable color characteristic along its length which comprises the steps of lock stitching together a plurality of strands including 'at least two chain forming strands of dilerent color characteristics around a core strand on a chain-forming mandrel, drawing off the cored chain yarn so formed with relation to the lock stitching at a rate of atleast two stitches per inch and selectively applying a heavy resistance to one only of said chain forming strands to cause said strand to form tight loops and' anyremaining strand to form elongated loosely formed loops about said core, and shifting said heavy resistance in rotation from one to another chain forming strand to cause each chain forming strand in turn to form tight loops and any remaining strand to form elongated loosely formed loops, and thereby to produce a substantial preponderance of different strands and corresponding different color characteristics in different lengths of said yarn.

References Cited in the file of this patent UNITED STATES PATENTS 1,802,337 Decker et al Apr. 28, 1931 1,825,454 Haussler Sept. 29, 1931 1,860,030 Hinchliir May 24, 1932 2,137,692 Linke Nov. 22, 1938 2,297,061 Knaus Sept. 29, 1942 2,316,060 Fullerton et al. Apr. 6, 1943

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