US3040551A - Stretch fabric and method - Google Patents

Description

June 26, 1962 G. A. URLAUB 3,040,551

STRETCH FABRIC AND METHOD Filed Feb. 10, 1956 i 1 RIB WALE Tic]. E.

IN VENTOR 650265 A. Mel/I05 ATTORNEYS smarter Patented June 2 1962 3,059,551 STRE ECHFA RIC METHGD George A. Urlaub, Townshipbf Malone,

, Chasm Falls, NX. Filed .Feb. 10, 1 956, Ser. No. 564,657

14 Claims. (Cl. 66-197) This invention consists in structuralimprovements in stretch fabric and the method ofobtaining them. i

' Abroad object of the invention is to construct a stretch fabric either in fiat knitted or tubular knitted form with lines of demarcation defining strips, which among "other Another object o'fthis invention is to provide two-way stretch fabrics in the form of stripshaving ravel resistant but lnselvaged edges in fabrics knitted tubular and 'having ravel resistant semiselvage edges in "fabrics knitted fiat.

A more'spe'cific object of'the invention is to provide stretch fabrics in the form of strips which have substantially normal facility for stretch both longitudinally and laterally. l i

A still more specificobjectofj the invention is to provide a novel form of fabric structure "of the interlock ribbed type.

Other objects of the invention are to provide various methods of knitting these fabrics.

As the disclosure proceeds, manyother and additional detailed objects and advantages of the invention both as to product and method will become apparent to those skilled in the art. 7

In the accompanying drawings,

lF-IGURE lis an-enlargedxsomewhat diagrammatic view of a piece of interlock double ribbed fabric illustrating the line of demarcation between two fabric sections, and the method of weakening the fabric along these lines;

FIGURE '2 is a top plan edge View in diagrammatic form of the structure of the fabricofF-IGURE 1;

and extensibility to provide varying degrees of binding pressure over .the entire area to be treated. This ability to stretch in two directions is of particular use in applying splints because these bandages will apply equal pressure .in all directions notwithstanding the contour irregularities encountered with splints. It also follows, of course, that the tWowaystretch surgical bandage'will apply the desired pressure throughout the entire area regardless :of its configuration such as produced, for example,-by'the ankle bone. v a

It is also highly desirable thatjbandages of this type can be used to apply varying degrees of pressure in the chest and pelvic areas, which is only possible With a twoway stretch fabric ofsuitable elasticity and extensibility.

In accordance with this invention these characteristics of a knitted surgical bandage can be adjusted over a FIGURE 3 illustrates diagrammaticallyhow the fabric of this invention can be knit .in tubular-form witha plurality of defining weakness lines to provide a number of strips of diiferent' widthswhen the fabric is separated along these defining lines; and

1 FIGURE 4 is an enlarged fview 0f the latch needle modified for use in the knitting process of this invention for the purpose of forming lines ofw'eakness in the fabric. The following disclosure will make frequent'referen'ce to the utility of the subject matter of this invention as applied to-surgic a'l bandages, but those skilled in' the art will understand that the principles of this invention are notlirnited to the production'of this particular product.

However, the advantages of the invention have special application to the production of surgical bandages, which explains their emphasis.

Stretch fabrics are desirable and Widely used for bandages and have in the past generally been made-of woven material. The common practice has been to weave them of highly twisted cotton yarns alone or in combination with covered rubber yarns, so as to achieve some degree of elasticity and extensibility. One of the important disadvantages of woven fabric surgical bandages is found in the fact that they have useful :stretch'ability lengthwise only and have substantially no widthwise stretch. Obviously a surgical bandage would fit the'various body consurgical bandage strips with varying degrees of elasticity wide range by the proper selection of yarns and knitting practices. Therefore, in accordance with this invention synthetic -or 'similar type-of filament or staple yarns which have been thrown or processed to make them so-called stretchf yarns, are essential. These yarns can be of,

synthetic material or combinations thereof with natural fibers. Suitable synthetic yarns are of the thermo-sensitive type composed of fibers of the polyarnide or nylon type, polyester and "celluloseester yarns such as are currently being used in the :knittingindustryc It is not intended to limit this invention to these types of yarns since any stretchable or lively yarn whether of the crimp or.

twisted type is suitable.

' It 'is preferred to limit the fabric of this invention on aninterlock type of circular knitting machine, although its-use is notessential to the attainmentof these objects. It is also possible to uses spring needle machine having one or two sets of needles'such as a Wildman, Tompkins or Cooper machine, circular machines generally, 'tricot milanese and Simplex, Raschel or 'Cidega types of warp knitting :machines, or flat bar knitting machines of the Cotton, Lamb or Dubied types. The invention 'will be described in more detailas applied to thel knitting of the fabrics of this invention on an interlock type of circular knitting machine.

a "In order toproduce the weakened lines'of demarcation in the tubular fabric being knit on such machines, to provide a plurality of defined fabric strips, certain knitting needles are left out of action preferably from the cylinder in the case of a circular machine and the front bed of a i-ng the severed loops of the dial needle and opposite this in ithe fabric, a'single wale ofyarn' floats at the cylinder needle, thereby providing, at regular intervals, 'in a round tube, depending upon the needle selected, lines of demarcation and weakness. "When'the tube is severed into a series of strips along these lines, there is produced a plurality of non-selvage strips suitable for many uses, including use as surgical'bandages. I

However, during the knitting it is clear that the fabric being constructed remains in the form being knitted which can be subjected to the necessary further processing including shrinking, dyeing, finishing, etc.

By using thermo-plastic yarns which have been or can be beat set, shrinkage accomplished by definite further processing causes the fibers or yarns which have been cut during the knitting to shrink back to adjacent wale loops and form a kind-of anchor to ,prevent ravelling of the strips along their cut edges when later cut into strips. The uncut or floated yarns when severed to form the strips also shrink back into a locking association with the adjacent wales, so that ragged, ravelled, non-selvage edges do not result.

One example of the method and the resulting product of producing this invention will be given in connection with a Scott & Williams interlock machine having a 26" cylinder. It is desired, of course, to knit the strips with a minimunnor if possible complete absence of waste. On a 26 cylinder machine having 1960 needles in the cylinder the operation can be set up to produce 8 strips of 3" wide bandage and 8 strips of 4" wide bandage Without any waste. In order to do this, as diagrammatically illustrated in FIGURE 3, the needle bank is subdivided into sections so to speak by removing certain of the needles from the cylinder. For a machine of the size assumed and the number of strips of the width defined, it is apparent first that there will be available 106 needles for each 3" width of strip and 139 needles for each 4" strip. In each of the smaller groups, of which there are 8, the 106th needle will be removed and in each of the larger groups the 139th needle will be removed. These assumptions are diagrammatically illustrated in FIGURE 3.

With this arrangement of needle groups the folds of the fabric as it runs through the take-up device, will occur at the positions indicated by the double headed arrow in FIGURE 3. As shown, there will be a set of four 3" strips at the top and a set of four 3'. strips at the bottom. Also, there will be a set of 4" strips at the left side and a set of 4" strips at the right side. Thus, with this needle bank it is possible to subdivide the two folds into 16 strips, 8 of which are 3" wide and 8 of which are 4" wide, avoiding any waste.

In a similar way each dial needle opposite the cylinder needle which has been put out of operation is constructed to sever the loop which is formed thereon. A needle suitable for this purpose is illustrated in FIGURE 4. The needle is provided with the usual shank 26, hook 28, latch 30, pivotally mounted at 32 in the cheeks 34 formed on the shank. I In other words, except for the forward position of the hook, this is the usual latch needle for a machine of this kind. However, in accordance with this invention it is modified so as to provide a sharpened edge at 36 on the needle body and hook, and a sharpened edge 38 on the latch, which cutting edges act during loop formation and pull down to weaken and finally sever that particular loop.

These operations will be better understood by reference to FIGURES l and 2. A piece 10 of interlock double-rib type fabric, made in accordance with this invention, is illustrated in FIGURE 1. .The white yarn 12 is knitted to provide a course which comprises loops formed successively upon alternating cylinder and dial needles, and more specifically upon every other needle, say the oddnumbered or short needles of each bank of needles, cyl inder and dial.

Similarly, the black yarn 14 is knitted to provide a course of loops formed successively upon alternating cylinder and dial needles, and more specifically upon every other needle, say the even-numbered or long needles of each bank of needles, cylinder and dial.

The same procedure was followed in the case of the two preceding courses knitted of the yarns 16 and 18, as shown in FIG. 1. As is well understood by those skilled in this art, the preceding courses of the fabric were similarly knit of other pairs of yarns, all in accordance with the normal procedure in knitting interlocked double-ribbed fabrics, see for example the Scott Patent No. 899,439, issued September 22, 1908.

Thus, as indicated above and as disclosed in the Scott patent, the fabric of FIGS. 1 and 2 is knit of two groups of yarns.

Thus, the wales and courses comprising one face, say the front of the fabric shown in FIGURE 1, consist of loops formed alternatingly of the black yarn and the White yarn in each wale and in each course. A similar sequence is in effect in the other face, the back of the fabric as shown in FIGURE 1.

The result is that this two-ply fabric is provided at each cylinder needle position where the needle is out of operation with a partially weakened wale forming a visual line of demarcation between adjacent strips on each side thereof without completely severing the fabric so that it can be shrunk, dyed and otherwise processed as a single piece of material and in the form of a tube. Under my invention, when producing it upon the interlock type of circular machine, series of floats are in one face of the fabric and they span the space of one or more needles which were left out to serve as markers or valleys for subsequent folding or cutting, while in the opposite face there are produced certain wales, directly opposite these fioats, in which the yarn is partly or wholly severed as shown in FIGURE 1.

Upon completion of the processing of the fabric, the floats 22, 24 along the weakened wale loops 2021 are cut to subdivide the knitted fabric into the strips referred to above. Those skilled in the art will appreciate from the above that the tube can be subdivided into strips of other widths with little or no waste by the proper selection of the cylinder needles which are taken out of operation and the association therewith in the dial of modified cutting needles to perform the functions described above. In other words, the spacing between the lines of weakness and visual demarcation can be varied as conditions require to provide different strip widths.

In the making of stretchable strips for other uses, as for example garment waistbands and cuff sections, the cylinder needles put out of operation are selected so as to float the stitches at the fold-over line without employing cutting needles at that point, but with the cutting needles spaced two strip markers apart. In other words, at the fold-over line the dial cutting needle is not used, but at the adjacent position on each side where the cylinder needle is put out ofoperation, the cutting needles are provided.

FIGURE 2 is a diagrammatic edge plan view of the fabric of FIGURE 1 and illustrates further the relationship of the loops formed by the two yarns for an interlock type of double-rib fabric, modified as described above to cut loops and float yarn along designated wales to subdivide the fabric piece into identifiable strips of the desired width.

FIGURE 2 shows the edge plan view of the fabric of FIGURE 1, where the yarn fioats of one face of the fabric extend across one needle space only. In some cases and for certain end uses of the product of this invention, it may be desirable to have the yarn floats traverse, say, 2-needle or 3-needle spaces, and also not to have the loops of the opposite wale cut or severed.

At this point it may be noted that it is within the contemplation of this invention to use various other forms of cutting instrumentalities as a substitute for the structure shown in FIGURE 4, and including sharpened sinkers or knock-over bits which in some types of machines can perform the severing function in the same way.

The fabric of this invention, of course, is not limited to production on circular knitting machines, or even doublerib interlock machines, but can be made on any other types including flat bed machines having single or double banks of needles.

It is also possible to produce the product of this invention on small diameter circular knitting machines of single-head or multi-head types in definite tubular sizes to reduce the number of cutting operations in the small size strips for bandages and other uses. Even in the case of warp knitting machines as the Raschel, tricot, Simplex, milanese Cidega, and by use of two warps, an end of the front warp or top warp as the case may be, can be laid into a cutting needle in its proper place in the machine to effect a cut loop wale, while the second or back warp will be floated acrossthe cut loop Wale. Any of these procedures producesthe effect and structure disclosed herein as fully as in the case of the interlock fabric.

The fabric can also be made on a single bed flat machine such as the Cotton type machine. In this machine the fabric of my invention can be produced in several ways. For example, by knitting into the fabric two yarns instead of one into those loops which form the strips, and knitting in one yarn instead of two into those loops which serve to unite the strip portions of the fabric until it is-siibsequently cut into narrower strips. One way of doing this is by plating a second series of yarns and traversing the carriers containing these yarns over the needles of predetermined strip widths, while at the same time a second carrier containing another separate yarn traverses the full needle-bar width to form that single yarn thickness between the strips, either being knitted or floated, and becoming the marker or valley lines of the subsequent fabric cutting operation. Another way of accomplishing my invention on the Cotton-type machine is to run one yarn as a main yarn and a second yarn as a plating yarn across the full needle bar width, and having the plating yarn laid into a second position in the throat of the plating sinker placed at the strip marker needles, said throat being so arranged to cut all or part of the plating yarn at this particular place in the fabric. By these methods I achieve a strip-marker valley or cutting operation demarcation and/or a partial severing of the yarn ends, which in turn produce one or more locked selvage, semi-selvage and unselvage edges. Still another method would be by overlapping the traverse for, say two needles, of two or more twin-tube yarn carriers, with the yarn tubes spaced, for example, four needles apart.

In the case of other springor latch-needle machines using one set of needles, the fabric of my invention can be produced by the techniques of float stitches, special sinkers, or both in the strip-marker areas, as will be evident to anyone skilled in the art.

It is believed that in view of the above detailed disclosure those skilled in the art will appreciate the flexibility of the method herein disclosed and the applicability thereof to the production of knitted fabric of various kinds and on many types of machines. It is preferred, therefore, that the scope of this patent be determined not by the examples given herein by way of illustration, but by the appended claims.

What is claimed is:

1. A knitted interlock fabric subdivided into a plurality of strips by spaced wales composed of cut loops and heats.

2. A double rib knitted fabric having a plurality of spaced visible walewise lines composed of cut loops and floats.

3. The fabric of claim 2 being knit of stretch yarn.

4. A twp-way stretch interlock knit fabric consisting of a plurality of connected strips divided by walewise lines of weakness, said strips being connected at said walewise lines by yarn floats only.

5. A method of knitting a fabric of two groups of yarns including the steps of severing loops of yarn of one group along a plurality of spaced wales and floating yarn of the other group across said wales to form visible strips.

6. A method of forming a plurality of strip defining lines in an interlock fabric knitted of two groups of yarns, comprising severing loops of yarn of one group along a plurality of spaced wales and simultaneously floating yarn of the other group across said spaced wales.

7. A knitted fabric comprising a series of connected strips each comprising two groups of stretch yarn loops in each course, said strips being connected by narrow walewise lines consisting of yarns of one of said groups. 8. A knitted fabric comprised of two groups of stretch yarns having knitted-in vertical lines of demarcation formed by yarn floats to form visible strips of definite widths, said strips being substantially non-ravelling at their side edges when the fabric is out along said lines of demarcation to provide said strips.

9. In the combination of claim 8, said fabric being ribknit.

10. In the combination of claim 8, said fabric being double rib-knit.

8, said fabric being References Cited in the file of this patent UNITED STATES PATENTS 575,012 Sturgess Jan. 12, 1897 1,120,989 Williams Dec. 15, 1914 1,552,483 Hinohliif Sept. 8, 1925 2,127,139 Reynolds et a1. Aug. 16, 1938 2,184,088 Weinberg Dec. 19, 1939 2,203,948 Dupuis June 11, 1940 2,421,357 Saftlas May 27, 1947 2,433,279 Johnson Dec. 23, 1947 2,466,536 Cooper et a1 Apr. 5, 1949 2,560,872 Pares et al July 17, 1951 2,564,245 Billion Aug. 14, 1951 FOREIGN PATENTS v a 524,698 Great Britain Aug. 13, 1940 fabric having

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