US3656323A

US3656323A - Tubular fabric article and method for making same

Info

Publication number: US3656323A
Application number: US3618A
Authority: US
Inventors: Russell L Brown
Original assignee: Union Carbide Corp
Current assignee: Union Carbide Corp
Priority date: 1970-01-19
Filing date: 1970-01-19
Publication date: 1972-04-18
Anticipated expiration: 1989-04-18
Also published as: CA947526A

Abstract

A tubular article which may be a continuous web of successive flat, open-ended tubes of knitted fabric, or a single such openended tubular article cut along seam areas from such a web, for example, a tubular warp knitted garment, is provided with cross interlooped, narrow strips on each opposite side of each seam area, the strips being separated by a wider, tubular strip so that when severed from the web along the center line of the tubular strip, the resulting seam will appear to be of the flat, plain type. The narrowness of the cross interlooped strips avoids build-up of excessive yarn tension. The open-ended tubular article is free of areas of excessive tension variance, especially along the seams, to produce the appearance of a uniform knitted structure throughout.

Description

United States Patent Brown [15] 3,656,323 [4 1 Apr. 18, 1972 [54] TUBULAR FABRIC ARTICLE AND METHOD FOR MAKING SAME 22 Filed: Jan. 19, 1970 21 Appl.No.: 3,618

[56] References Cited UNITED STATES PATENTS 459,866 9/1891 Clewley ..66/195 592,057 10/1897 Knight ..139/407 FOREIGN PATENTS OR APPLICATIONS 1,090 3/1955 France ..66/195 1,143,424 10/1957 France ..66/195 Primary Examiner-Ronald Feldbaum Attorney-Pearson & Pearson [57] ABSTRACT A tubular article which may be a continuous web of successive flat, open-ended tubes of knitted fabric, or a single such openended tubular article out along seam areas from such a web, for example, a tubular warp knitted garment, is provided with cross interlooped, narrow strips on each opposite side of each seam area, the strips being separated by a wider, tubular strip so that when severed from the web along the center line of the tubular strip, the resulting seam will appear to be of the flat, plain type. The narrowness of the cross interlooped strips avoids build-up of excessive yarn tension. The open-ended tubular article is free of areas of excessive tension variance, especially along the seams, to produce the appearance of a uniform knitted structure throughout.

7 Claims, 7 Drawing Figures TENSION (GRAMS) INVENTOR RUSSELL L. BROWN ATTORNEYS BACKGROUND OF THE INVENTION This invention relatesgo the makingof fabric from elongated strands and especially to the making of relatively finished, open ended tubular gannents in continuous web form, ready to be severed into individual garments, or equivalent articles. While the invention can be used to advantage in circular knitting, it is especially useful in the relatively high speed warp knitting of a continuous web of horizontal, open ended, tubular garments, adapted to be cut along seam areas into individual garments as disclosed in U.S. Pat. application Ser. No. 776,938, filed Nov. 19, 1968 and owned by a common assignee.

In Ser. No. 776,938, a plurality of stretchable retractive warp yarns extend walewise of the web, in both sets of warp yarns so that when the horizontally extending, or coursewise extending, tubes are cut into individual garments. and turned through 90, the stretchable retractive yarns will be running circumferentially of the garment. The single ply seamareas of the web, which connect the two ply tubular body portions thereof have the yarns of one set cross interlooped into the yarn stitches of the other set. If the seam areas, or strips, are relatively wide, for example one-half inch, or 1 inch, the knitting tension on the stretch, and non-stretch, body yarns increasesprogressively from one side of the strip where, for example, it may normally be about 2 grams, to the other side of the strip, where it mayhave built up to eight to ten gramsand be disadvantageous.

Not only may tension thus build up to an undesirable degree in such a seam strip, but it has been found that the crossinterlooping of the two plies, at the cut edges of the seams when the articles have been cut from the web, is notpresently attractive to the trade. It has been found to be more commercially acceptableto cause the cut edges of the seams to give the appearance of the sewn, flat plain type seams, with which the garment trade has long been familiar.

SUMMARY OF THE INVENTION In this invention, therefore, instead of providing a continuous web of two ply open-ended tubular areas connected by seam and severing areas which are cross interlooped entirely thereacross and nontubular, the seams have only a narrow strip of cross interlooping on each opposite side of a two ply, open-ended tubular or tunnel, strip. Thus the cross interlooping is continued just long enough to secure a good joinder, for example about stitches, or courses,-but not long enough to cause an appreciable increase in yarn tension due to the longer path followed by the yarns in joining the two plies. In

' addition, by providing a relatively wide central tubularstrip in the seam area, for example, at least stitches, when the seam is out two loose, or free, edges appear along the seam which closely resemble an ordinary flat plain seam such as long used by garment makers. If a hemmed seam, a corded seam or any other well known seam was desired, thefree edges of theseam of the knit product of the invention lend themselves to the making of the same.

It will be understood that the amount of warping tension varieswith'many factors, depending on the denier and composition of the strands so that in Raschel fabrics such as power net, tension may be from 20 to 40 grams per end, depending on the gauge of the machine. The finer the gauge the greater the tension, but the yarn should be run at the lowest possible tension consistent with good results. The tension examples specified herein are illustrative only, the invention recognizing that excessive tension produces a higher breakage rate, harder warp, streaking, etc., and being intended to avoid magnification of tension variance across the seam and severing areas of the web.

FIG. 1 is a schematic, perspective, front elevation of a typical warp knitting machine for forming fabrics from interconnected flexible strands, the machine producing a continuous web of open-ended tubular articles.

FIG. 2 is an enlarged fragmentary, side edge view of the continuous web shown in FIG. 1. I

FIG. 3 is a view similar to FIG. 2, showing a tubular article cut from the continuous web thereof.

FIG. 4 is a view similar to FIG. 3 showing the article of FIG.

3 turned inside out to hide the seam.

FIG. 5 is a front elevation of the tubular article of FIG. 3.

FIG. 6 is a diagrammatic view including a graph to show the DESCRIPTION OF THE PREFERRED EMBODIMENT As shown in the drawing, the machine 16 schematically dcpicts any typical, well known, knitting apparatus for producing simultaneously a pair of back to back, superposed, indepen dent webs of fabric. Machine 16 could be a weft, or warp, knit machine. Preferably, however, it is a Raschel warp knit machine such as typified by the 14 guide bar, double needle bar Fashionmaster made by Cooker Machine and Foundry Company and now well known in the trade. Machine 16 includes at least two separate sets, 17 and 18, of warp yarns which are warp knitted by the

double needle bars

19 and 20 and the multiple guide bars 21 to automatically produce the continuous two ply web 22 for wind-up on wind-up roll 23.

As fully described in detail in the above mentioned US. Pat. application Ser. No. 776,938, the continuous web 22 preferably includes stretchable retractive warp yarns 25, shown diagrammatically to run longitudinally, or warpwise, parallel to the direction of advance of the web, and the web includes a plurality of open ended, laterally extending, tubular garment areas 26 defined by a plurality of seam areas 27 in which the yarns of the front single knit fabric 28 are cross interlooped and interconnected with the: yarns of the rear single knit fabric 29 to form single ply, double knit, seam areas. In the said patent application, the cross interlooping in the seam areas, which may form the side edges of a garment when out from the web, extends entirely across the seam.

It has been found that, while satisfactory for many purposes, depending on the gauge of the machine, whether the strands are hard, soft, stretch or non-stretch and other factors, there may occur an undesirable increase in yarn tension from one side 31 of the seam to the other side 32, for example from 2 grams to 10 grams. It will be understood that in knitting strands from one fabric 28 over into the other fabric 29 of the web, extra yarn is required and that with each stitch of the cross interlooped scam the tension progressively accumulates. This is shown diagrammatically in FIG. 6 wherein the yarn tension is shown to increase progressively to a peak 33 and then drop back to normal when the cross interlooping 34 ceases and a new tubular, unconnected garment area is started.

In this invention, as shown in FIG. 7,. the interconnection of the back to back superposed

fabrics

28 and 29 by cross interlooping of the respective strands of the fabrics into each other, or other cross connection, in the seam areas 27 of the continuous web 22 occurs only in a pair of spaced apart, parallel, short, or narrow,

strips

36 and 35 each at an

opposite side

31 or 32 of each seam area 27. The articles being made on machine 16 are preferably garments such as girdles, panty girdles, sweaters or the like, which, if made of two pieces of fabric joined together by sewn seams, would normally be 10 to 20 inches in width when flat and would normallyhave seams of the flat sewn plain type of about one quarter to one-half inches in width. The seam areas of this: invention, include the central portion, or strip 37 in which the

fabrics

28 and 29. are

free of connection, or interlooping to form open-ended tubes, or tunnels, and along the centre line 38 of which, the web 22 may be cut into individual gannents such as the girdles 39 of FIGS. 3, 4 and 5.

It will be understood that when reference is made to relatively wide or large tubular garment areas herein, an adult, or child, sweater or panties, of to inches in width when flat, is in mind. Reference to relatively less wide seam, or severing, areas dividing the web into such garment areas has seam areas of perhaps one-half inch to 1 inch in width in mind. Thus when the web is cut along the centre line of such seam areas there will be a short, or narrow, interlooped

strip

35 and 36, perhaps 10 stitches, or courses, in width which define the periphery of the body 41 of the garment and integral, free, loose extension, or

edge flap

42 and 43, about one-eighth to one-half inch in width, and at least about 20 stitches in width, corresponding to a flat plain type seam.

As best shown in FIG. 3, the garment 39, or other article cut from the continuous web 22, includes the generally tubular body 41 formed of front fabric panel 28 and rear fabric panel 29, and preferably including stretchable retractive yarns which run walewise of the fabric, but circumferentially of the garment. The garment 39 has been severed from web 22 along centre lines 38 of the seam areas 27, and along the centre line 38 of the tubular central portions 37 of the seam area so that integral

free extensions

42 and 43 are seen, while the narrow interloop strips or 36 are juxtaposed to, and define the periphery of the garment body 41.

Not only is yarn tension increase avoided at the seams, but the cut articles are most acceptable commercially in the garment trade as resembling a seam with which the operators are familiar when flat as in FIG. 5 or when inverted as in FIG. 4.

It should be noted that the warp knitting machine 16 produces the web 22 continuously for unidirectional advance, in a known manner characteristic of such machines. The method of the invention requires no backward movement of the web, no increased density of the stitches and no provision of close spaced, dense reinforcing bands, alongside the seams, or similar expedients of the prior art, for obtaining fabric alignment and avoiding openings in the product.

What is claimed is:

1. In a generally open-ended, tubular knitted garment of the type having a warp knit body formed of a single knit, front fabric panel and a single knit rear fabric panel, each panel comprising one of a pair of separate sets of interknitted warp yarns, said sets of warp yarns being cross interlooped, one with the other, to form double knit, side edge seams in said garment;

the improvement comprising the cross interlooping of said double knit, side edge, seams only in a narrow strip juxtaposed with, and defining, the periphery of said body, said strip being a predetermined number of stitches in width, insufficient to adversely increase stitch tension, and said body being free of areas of excessive tension proximate said periphery,

the remainder of said seams comprising integral extensions on said narrow, cross-interlooped strip, extending therealong and therefrom said extensions being formed of said single knit fabrics,

whereby said seam gives the visual impression of a sewn, flat plain, seam on a conventional seamed knitted garment.

2. An open-ended, tubular, knitted garment as specified in claim 1 wherein:

said fabric panels are of the type having stretchable-retractive yarns running walewise thereof, but running circumferentially of said tubular garment, said stretchable retractive yarns being at predetermined, relatively low, tension and forming the said cross interlooped strips of said seams, and

the width of said cross interlooped strip is no more than about 10 courses with a knitting tension of only about two grams, and the width of the said integral, single knit extensions of said seam are at least twice the width of said strip.

3. As an article of manufacture,

a continuous web formed of at least two superposed, back to back, unconnected, plies of fabric each ply warp knitted, of a plurality of elongated strands, said web having walewise spaced apart, coursewise extending spaces dividing said web into a plurality of coursewise extending, open ended, two ply, generally tubular areas whereby said web may be severed along the centre lines of said seam areas into a plurality of individual open-ended articles, each having an edge seam of sewn, flat, plain type appearance.

and seam areas in said web, in said coursewise extending spaces between said two ply tubular areas thereof, the strands of one said ply being interknitted with the strands of the other said ply along a pair of substantially parallel, narrow, single ply strips in said seam areas, said strips being separated by an open-ended, tubular, two ply strip of substantial width to permit said seam areas of said web to be severed to form a plurality of individual tubular fabric products therefrom, each said product having seams which resemble a sewn flat, plain type seam.

4. As an article of manufacture,

a continuous elongated web of fabric formed of a pair of back to back, superposed, unconnected warp knit single fabrics, each free of areas of excessive tension variance, said pair of fabrics forming a plurality of laterally extending, open ended tubes of predetermined area and predetermined tension spaced apart, and defined by a plurality of relatively narrow laterally and coursewise extending seam areas wherein the strands of one fabric are cross interlooped into the strands of the other fabric in a pair of narrow, parallel strips of slightly increased tension separated by a wider open-ended tubular portion in which the strands of said fabrics are under reduced tension and free of said cross-interlooping;

5. An article of manufacture as specified in claim 4 wherein:

said warp knit fabrics, each include stretchable retractive strands extending longitudinally thereof, and forming part of said seam areas, said strands having a predetermined, relatively low tension,

said narrow strips of cross interlooped strands are no more than about 10 stitches in width, to avoid adverse build-up of knitting tension in said strands, and

said tubular portion of said seam areas, between said narrow strips is at least about twenty stitches in width to give a sewn seam appearance.

6. In the process of warp knitting two sets of warp yarns into a continuous two ply web of back to back, superposed single knit fabrics formed into open ended tubular articles by a plurality of narrow seam areas in which the warp yarns of one fabric are cross interlooped with the warp yarns of the other fabric to form a single ply in the seam area,

the step of cross interlooping the yarns at one edge of said seam area only for a predetermined number of stitches insufficient to build up adverse tension,

then continuing to warp knit a relatively wide central portion of said seam areas, as back to back, superposed, single knit fabrics free of cross connection, and

then again cross interlooping the yarns at the opposite edge of said seam area, only for said predetermined number of stitches insufficient to build up adverse tension, to thereby form an open ended tube seam area,

said steps being performed while said fabric advances unidirectionally, while running said strands at the lowest possible tension consistent with good results and without magnification of any tension variance,

said steps permitting said seam area to be severed along the centre line thereof to give the appearance of a sewn, flat, plain type seam.

7. The process of knitting on a two needle bar, multiple guide bar Raschel warp knitting machine a plurality of generally open-ended tubular articles of fabric which comprises the steps of:

are cross interlooped into a doubled fabric at substantially unchanged tension, a spaced apart parallel pair of said narrow strips separating each seam area from each garment area and defining an open ended tube therebetween.

mg V UNITED STATES PATENT OFFICE CERTIFICATE O CORRECTION Patent No. 3 ,656,3Z3 Dated April 18 1972 Invent0 (s) Russell L. Brown It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column l,line 56, after "least" insert -about--.

Column 4, claim 3 delete lines 8 through ll inclusive.

Column 4, claim 4, insert at the end after cross-- interlooping" line 36: --whereby said web may be severed along the centre lines of said seam areas into a plurality of individual open-ended articles each having an edge seam of sewn, flat, plain type appearance.--

Signed and sealed this 10th day of October 1972.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents

Claims

1. In a generally open-ended, tubular knitted garment of the type having a warp knit body formed of a single knit, front fabric panel and a single knit rear fabric panel, each panel comprising one of a pair of separate sets of interknitted warp yarns, said sets of warp yarns being cross interlooped, one with the other, to form double knit, side edge seams in said garment; the improvement comprising the cross interlooping of said double knit, side edge, seams only in a narrow strip juxtaposed with, and defining, the periphery of said body, said strip being a predetermined number of stitches in width, insufficient to adversely increase stitch tension, and said body being free of areas of excessive tension proximate said periphery, the remainder of said seams comprising integral extensions on said narrow, cross-interlooped strip, extending therealong and therefrom said extensions being formed of said single knit fabrics, whereby said seam gives the visual impression of a sewn, flat plain, seam on a conventional seamed knitted garment.

2. An open-ended, tubular, knitted garment as specified in claim 1 wherein: said fabric panels are of the type having stretchable-retractive yarns running walewise thereof, but running circumferentially of said tubular garment, said stretchable retractive yarns being at predetermined, relatively low, tension and forming the said cross interlooped strips of said seams, and the width of said cross interlooped strip is no more than about 10 courses with a knitting tension of only about two grams, and the width of the said integral, single knit extensions of said seam are at least twice the width of said strip.

3. As an article of manufacture, a continuous web formed of at least two superposed, back to back, unconnected, plies of fabric each ply warp knitted, of a plurality of elongated strands, said web having walewise spaced apart, coursewise extending spaces dividing said web into a plurality of coursewise extending, open ended, two ply, generally tubular areas whereby said web may be severed along the center lines of said seam areas into a plurality of individual open-ended articles, each having an edge seam of sewn, flat, plain type appearance. and seam areas in said web, in said coursewise extending spaces between said two ply tubular areas thereof, the strands of one said ply being interknitted with the strands of the other said ply along a pair of substantially parallel, narrow, single ply strips in said seam areas, said strips being separated by an open-ended, tubular, two ply strip of substantial width to permit said seam areas of said web to be severed to form a plurality of individual tubular fabric products therefrom, each said product having seams which resemble a sewn flat, plain type seam.

4. As an article of manufacture, a continuous elongated web of fabric formed of a pair of back to back, superposed, unconnected warp knit single fabrics, each free of areas of excessive tension variance, said pair of fabrics forming a plurality of laterally extending, open ended tubes of predetermined area and predetermined tension spaced apart, and defined by a plurality of relatively narrow laterally and coursewise extending seam areas wherein the strands of one fabric are cross interlooped into the strands of the other fabric in a pair of narrow, parallel strips of slightly increased tension separated by a wider open-ended tubular portion in which the strands of said fabrics are under reduced tension and free of said cross-interlooping;

5. An article of manufacture as specified in claim 4 wherein: said warp knit fabrics, each include stretchable retractive strands extending longitudinally thereof, and forming part of said seam areas, said strands having a predetermined, relatively low tension, said narrow strips of cross interlooped strands are no more than about 10 stitches in width, to avoid adverse build-up of knitting tension in said strands, and said tubular portion of said seam areas, between said narrow strips is at least about twenty stitches in width to give a sewn seam appearance.

6. In the process of warp knitting two sets of warp yarns into a continuous two ply web of back to back, superposed single knIt fabrics formed into open ended tubular articles by a plurality of narrow seam areas in which the warp yarns of one fabric are cross interlooped with the warp yarns of the other fabric to form a single ply in the seam area, the step of cross interlooping the yarns at one edge of said seam area only for a predetermined number of stitches insufficient to build up adverse tension, then continuing to warp knit a relatively wide central portion of said seam areas, as back to back, superposed, single knit fabrics free of cross connection, and then again cross interlooping the yarns at the opposite edge of said seam area, only for said predetermined number of stitches insufficient to build up adverse tension, to thereby form an open ended tube seam area, said steps being performed while said fabric advances unidirectionally, while running said strands at the lowest possible tension consistent with good results and without magnification of any tension variance, said steps permitting said seam area to be severed along the center line thereof to give the appearance of a sewn, flat, plain type seam.

7. The process of knitting on a two needle bar, multiple guide bar Raschel warp knitting machine a plurality of generally open-ended tubular articles of fabric which comprises the steps of: warp knitting a pair of back to back, superposed, single knit, fabrics in a continuous web advancing unidirectionally along a path at predetermined warp tension; and dividing said web alternately into relatively wide open-ended, tubular, garment areas and relatively less wide, open-ended, tubular, seam areas by a plurality of relatively narrow strips in which the yarns of said single fabrics are cross interlooped into a doubled fabric at substantially unchanged tension, a spaced apart parallel pair of said narrow strips separating each seam area from each garment area, and defining an open ended tube therebetween.