US2375253A - Hosiery and method of making same - Google Patents

Description

May 8, 1945. SCHUBERT 2,375,253

HOSIERY AND METHOD OF MAKING SAME Filed June 17, 1945 3 Sheets-Sheet l H H HQ, 1 t'ww Z) 011 u ATTORNEY.

May 8, 1945.

E. SCHUBERT 2,375,253

HOSIERY AND METHOD OF MAKING SAME Filed June 17, 1943 5 Sheets-Sheet 2 INVENTOR. Elfin Er? [o u'a ScMez Q BY mm WM/1A May 8, 1945. E. SCHUBERT HOSIERY AND METHOD OF MAKING SAME Filed June 17, 1943 3 Sheets-Sheet 3 w mwm m H F Nip/ Two w H 4M H m U Au VHJPLH VH M HWK M HLVL W W W KK KH N? a VMMVAM VO K H WI V V1 6 MUELW n U U i l A i w m M [curls Icky-z BY elastic materials of silk or of rubber have Patented May 8, 1945 UNITED STATES PATENT OFFICE 2,375,253 HOSIERY AND METHOD OF MAKING SAME Edwin Louis Schubert, Philadelphia, Pa. -Application June 17, 1943, Serial No. 491,099

6 Claims. My invention relates to hosiery, and the method of making same, and it relates more particu-,

larly to full-fashioned hosiery adapted to cover the leg from the foot to the thigh.

Throughout the history of hosiery, the problem of conformity of the hose to the leg has forever presented itself. Attempts have been made to solve this by various means, none of which in the past has been unqualifiedly successful. Thus, been used in order to cause the hose to conform to the leg without bagging; but rubber threads are coarse and unsightly, whereas silk has been difficult to obtain and, because of the varying strains due to the diverse widths of the leg at different portions thereof, appears taut in some places and loose in others.

Another method developed in an attempt to solve this problem has been to knit the hose in a panel form, successively reducing the number of needles per course from the thigh to the ankle, and then to seam the side edges together, thereby to form a substantially inverse-conical covering for the leg. This, however, does not compensate for the varying strains of the knee portion, the narrowing of the leg at the knee and widening therefrom toward the calf, nor for the widening and narrowing at the ankle portion.

Moreover, I have discovered that the yarns of which such stockings are made, particularly those which comprise a plastic substance such as rayon, etc., have a relatively low elastic limit, beyond which they stretch through a relatively large proportion of the original length of the yarn before arriving at the breaking point.

Furthermore, I discovered that after the elastic limitis reached, and when the tension on the stretched yarn is released, the yarn tends to recover its original length to a degree, but this recoverability is not sufficient to regain its original length. Moreover, when the yarn is again stretched, it will exercise properties of recoverability up to the tension which originally stretched it beyond the elastic limit. The ratio of tension to elongation in the restretching process is not the same as the tension-elongation ratio in the recovery process, and the result when pictured on a graph may be termed a hysteresis loop.

One important element of this observation, however, is that the base of this loop is behind the top of it, considering the degree of elongation as the abscissa, and the amount of tension as the ordinate, the intersection of the abscissa and the ordinate being taken as zero. Another important element of. this observation is thatnew hysteresis loops may be established for each successive increase in tension, right up to the breaking point. This may readily be seen by'reference to Figure 1 of the drawings, hereinafter described.

Thus, there is in efiect established a new "elastic limit for the yarn each time it is stretched beyond the former elastic limit; and that each time, the base limit of recovery is itself moved up. Moreover, there is a very large degree of stretchability, usually many times the degree of original elasticity, available for setting up new elastic limits before the breaking point is reached.

In addition, I have'discovered that these yarns usually have a relatively low rate of elongation per tension load until the elastic limit is reached, and then lengthen rapidly to a remarkably high rate of elongation per tension load, until several times the elasticrlimit elongation is reached, whereupon the rate of elongation diminishes and tends to approach the rate of elongation of the original elastic limit. However, the rates of elongation and recovery per tension load, of the hysteresis loops, are substantially constant regardless of their positions along the tension-elongation curve of theyarn.

Thus, two distinct results follow from this discovery:

First, a yarn which has imposed upon it a tension which carries it just beyond its elastic limit will stretch disproportionately to the tension load until it has been elongated beyond a critical point, beyond which its further elongation will be much more nearly proportionate to the increase in tension load. One theory for this disproportionate elongation is that the micellae of which the yarn is supposed to be composed are stretched beyond their original alignment and slide along with respect to each other until a new alignment is established, whereupon intermicellar cohesive attraction may be asserted with greater force. I may therefore call this stage of disproportionate elongation between the elastic limit and the critical point, the re-alignment stage.

Second, the rate of elongation per tension load in the hysteresisloops being substantially constant, while the tension load increases with retraverse a very substantially greater degree of elongation than the original elastic limit of the yarn. Moreover, these new elastic limits do not resolve into a disproportionate elongation stage such as the re-alignmentstage when these new effective elastic limits are passed in an ascending degree of tension. Instead, however, as tension is further increased, elongation increases to a less and less extent, and this elongation is immediately recoverable within the newly established hysteresis loop to a greater degree than any previous elongation.

Furthermore, in the formation of the individual loops of a knitted fabric, the yarn is bent to a degree beyond its elastic limit, thereby establishing in effect a new elastic limit. In addition, the knitted formation lends a considerable increment of effective elasticity of the fabric by giving the yarn "play in pulling through the loops when the fabric is under tension. This play is fully recoverable to the extent that the yarn is not stretched beyond its effective elastic limit when the fabric is under full tension, and is partially recoverable in all cases where the yarn is extended beyond its effective elastic limit,in accordance with the hysteresis loop. Moreover, tensioning the knitted fabric beyond the elastic limit of the yarn need cause no concern unless the yarn is so disproportionably tensioned as to completely distort the knitted fabric, and this would not be the case in fabrics knitted for ordinary wear as clothing. The reason for this reat leeway in tension is that the breaking point of such yarns is usually man times theoriginal elastic limit of the yarn.

In accordance with my discovery and the implications thereof, I have invented a full-fashioned stocking which embraces the peculiar characteristics of the hysteresis loops in such yarns,

operably to provide effective elasticity in portions of the stocking where elasticity is absent in stockings made of these yarns in present day practice. In such stockings as, for instance, in those made of a plastic such as rayon, such absence is particularly noticeable in the ankle portions, and also in the knee portions, the latter being frequently stretched up to or of their original widths in the normal flexing of the knee.

Moreover, in such stockings, the stretch takes place in the realignment stage, and there is therefore virtually no recovery thereof.

One object of my invention therefore is to provide a full-fashioned stocking made of plastic yarn such as rayon or other yarn, which isso constructed as to re-set the realignment stage with respect to the stretching requirements of the wearer so as to transcend the realignment stage elongation, thereby eliminating its effective ability to over-stretch the stocking when the stocking is worn.

Another object of .my invention is to provide a full-fashioned stocking made of a plastic yarn. which is so constructed as to provide at places subject to varying tensions, eflective elastic limits far in excess of the original elastic limits of the with the above and other objects in view, my

A further object of my invention is to provide invention consists of knitting with a plastic yam,

a full-fashioned stocking with so much fewer wales at the knee portion thereof than is normally required comfortably to cover the knee, as to cause the yarn at the knee portion to stretch beyond its realignment stage when the stocking is normally put on the leg.

My invention further consists of imposing on a full-fashioned stocking frequent narrowings between the thigh and the knee and widening the stocking from proximity to the knee, toward the calf.

My invention further consists of a full-fashioned stocking made of a plastic yarn such as rayon and comprising a thigh portion, a knee portion and a calf portion, said knee portion having fewer wales than either the thigh portion or the calf portion.

My invention also consists of a full-fashioned stocking made of a plastic yarn, comprising an ankle portion so much narrower than the ankle on which it is adapted to be worn, as to cause the yarn at said ankle portion to be stretched beyond the realignment stage when said ankle portion is first worn on said ankle.

For the purpose of illustrating my invention, I hav shown in the accompanying drawings forms thereof which are at present preferred by me, since the same hav been found in practice to give satisfactory and reliable results, although it is to be understood that the various instrumentalities of which my invention consists can be variously arranged and organized and that my invention is not limited to the precise arrangements and organizations of the instrumentalities as herein shown and described.

Referring now to the drawings, in which like reference characters indicate like parts:

Figure 1 represents a tension-elongation diagram showing the effect of the application of tension on a plastic yam of which the hosiery of my invention is made; the degree of elongation being the abscissa, and the amount of tension being the ordinate, the intersection of the abscissa and the ordinate being taken as zero.

Figure 2 represents an elevatlonal view of a. knitted web or panel of full-fashioned hosiery -made in accordance with my invention, showing said panel as it comes off the knitting machine, prior to seaming.

Figure 3 shows a completed full-fashioned stocking embodying my invention.

Figure 4 represents an enlarged, fragmentary view illustrating the narrowings between the thigh and the knee portions of the full-fashioned stocking embodying my invention.

Figure 5 represents an enlarged, fragmentary view illustrating the widenings between the knee and the calf portions of the full-fashioned stocking embodying my invention.

Figure 6 represents the full-fashioned stocking embodying my invention as it appears on the leg.,

For purposes of illustration, I shall herein describe my invention as applied to a ladies size 9 /2 stocking, although my invention is equally adaptable for any size of any stocking.

Thus, in accordance with my invention, I set asmaos D, and reducing to a. width or five courses at the knee portion E of the narrowings A.

I then set up a back-rack adapted to operate with narrowing needles, operably to provide widenings'F between the knee portion C and the calf portion G. In the ladies size 9 stocking, I preferably provide widenings disposed sixteen courses apart.

I then start the machine, preferably using a bank of 420 needles for the welt H, carrying on with the same needles through the thigh portion B, and reducing the needles by successive narrowings A until the knee portion C is reached, which portion, according to my invention, utilizes preferably but 356 needles. Continuing the run, successive widenings F take place until the calf portion G is reached, by which time preferably 398 needles are used for each course.

I then reset the narrowing chain so as to provide preferably 3''! narrowings down and preferably eight courses apart, extending from the calf region G to the shin region K. Continuing the run, therefore, I reduce the width of the courses from 398 wales at the calf to preferably 250 wales at the shin portion, including the portion embracing the ankles. The run is then continued to include the heel L, whereupon a foot M may be added separately or by the further run of the machine. The panel is then removed from the machine and is seamed as at N, thereby completing the full-fashioned stocking embodied in my invention.

It is to be understood, of course, that the numbers of needles in each bank, the resultant number of wales in each portion, the numbers of narrowings or widenings, and the courses therebetween may be varied according to the individual requirements of the size and shape of the leg.

for which the stocking is being made; just so that the width of the knee portion C is so substantially less than the minimum width of the human knee P, and the width of the-shin portion K is so substantially less than the shin and ankle portion Q of the human leg on which the stocking is adapted to be worn, that the yarn of said portions will, when the stocking is first put on the leg, be stretched beyond the "realignment stage R, operably to impose on said yarn a new effective elastic limit Shaving a greater efiective elasticity than that existing up to the original elastic limit T of the yarn. This new eiTective elastic limit S, as indicated hereinabove, would be the upper end of the hysteresis loop U. Moreover, as has been above indicated and as is now more fully explained, reference being had to the diagram embodied in Figure 1, this hysteresis loop U is longer, and traverses a greater degree of elongation u-u' than any previous hysteresis loop such as the loop V which traverses merely the degree of elongation vv, or the original elasticity extending from zero to T and traversing the degree of elongation tt'.

By reference to the diagram of Figure 1, it may readily be seen how the yarn is affected by tension. Thus, the abscissa a of the diagram represents the degree of elongation of a plastic yarn such as rayon, and the ordinate 1) represents the amount of tension to which the yarn is subjected; the base or intersection of the abscissa and ordinate being taken as zero.

Thus, as the tension increases, it may be seen that the elongation increases substantially in direct proportion to the tension increase until the elastic limit T is reached; whereupon the realignment stage R takes place. In this realignment stage, the micellae of the plastic yarn apparently flow with virtually little or no tension being required to bring about this flow. Moreover, when tension is released during this realignment stage the yarn recedes in elongation to a point 10 from its point of release 20, the net elongation being represented along the abscissa as w-w'.

The realignment stage R continues to the critical point x, whereupon further imposition of tension on the yarn results in less and less elongation until the rate of elongation per tension increase becomes substantially similar to the rate of elongation prior to reaching the original elastic limit. The realignment stage varies in length in various plastic yarns, but the characteristics herein described remain virtuallythe same.

When the tension on the yarn is increased beyond the elastic limit, as for instance to the point 0'', and is then released, the rate of recoverability per tension decrease is somewhat slower than the rate of elongation per tension increase, the resultant curve on the graph embodied in Figure 1 being in the form of a loop V which I prefer to call a hysteresis loop. The base of this loop is on the abscissa 0a, thereby indicating that there is no tension at that point. When tension is again imposed on the yarn after it has once been imposed thereon up to the point '0", the yarn will elongate per application of tension at the rate indicated by the curve V' until the yarn has again reached the point 12". If the tension should at that point he again re leased, the rate of its recoverability per tension decrease is indicated by the curve V"; the curves V and V" together forming the hysteresis loop V. So long as the tension imposed on the yarn does not increase beyond the point 1)", the yarn will always recover its length back to the point 12 along the curve V, when the tension is released; and will always increase in elongation per tension increase, along the curve V. For all practical purposes, therefore, there is established a new, effective elastic limit a". In like manner, hysteresis loops are formed everywhere along the curve T--S-B up to the breaking point B of the yarn.

One remarkable observation, however, concerning these hysteresis loops is that, regardless of where they originate along the curve TS-B, they are substantially parallel. Another important observation is that the depending axes of these hysteresis loops are inclined rearwardly toward the base 0. A further important observation is that the points of origin w", x, v", 5, etc., of the hysteresis loops are on a curve T-S-B, which is inclined at an angle to the ordinate 17 greater than the angles of said hysteresis loops to said ordinate b.

The result is that the nearer the point of origin of the hysteresis loops approaches the upper end of the curve TS--B, the longer is the hysteresis loop, and the greater the amount of abscissa traversed by said hysteresis loop. But the abscissa of said curve represents the degree of elongation, and the hysteresis loop represents inter alia the amount of recoverability of said yarn after it has once been elongated to the point of origin of said hysteresis loop. Hence, the more the yarn is stretched beyond the realignment stage R, the greater the degree of elasticity of the yarn. By a comparison of the hysteresis loop U, originating at the point S. with the curve 0-T, representing the original elasticity of the yarn, it may readily be seen how much greater the new eflective elastic limit Sis than the original elastic limit T. Also, from a" comparison of the elongation recoverability uu'-of the hysteresis loop U, with the elongation recoverability t-t', of the original elasticity O-T, it is apparent how much greater is the elongation recoverability of the hysteresis loop U than that of the original elasticity OT.

Furthermore, by a comparison of the tensionelongation curve U of the hysteresis loop U, with the tension-elongation curve O-T--S, repre-' senting the elongation accompanying the original tension imposed on the yarn, it is apparent how the effective elongation of the yarn has been decreased by initially stretching the yarn beyond the realignment stage. This decrease may, in

, fact, be mathematically computed by comparing elasticity, a tension great enough to bring the yarn of which said portions are made substantially beyond the realignment stages thereof, I have provided for said portions new, effective 3 elastic limits far in excess of the original elastic limit of the yarn, together with a far greater elasticity than that provided by the original elasticity of the yarn. Thus, the stocking embodying my invention has great elasticity where said elasticity is needed most, in spite of the fact that said stocking is made of a yarn which, when used in a stocking of usual construction, normally has far less elasticity than that which is required to cause said stocking to conform to the human leg in ordinary wear.

In practice, the original elastic limit '1 is so low as to afford very slight resistance to the wearer who has put on the stocking for the first time. This resistance is so slight, in fact, that the traversing thereof is actually unnoticed by the wearer. Moreover, when the tension put on the stocking by the wearer is increased until the point S is reached, the wearer senses no greater resistance than that normally expected from a silk stocking of good grade. Indeed, it is a silk stocking of good grade that the stockin embodying my invention approximates in the use of a lastic yarn.

I am aware that the invention may be embcdied in other specific forms without departing from the spirit or essential, attributes thereof, and I therefore desire the present embodiments to be considered in all respects as illustrative and not restrictive, reference being had to the appended claims rather than to the foregoing description to indicate the scope of the invention.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1.The method of making a. rayon stocking comprising the knitting of a thigh portion, narrowing the stocking toward the knee portion to substantially 85% of the original perimeter of the thigh portion, knitting a knee portion, widening the stocking toward the calf portion to substantially 95% of the original perimeter of the thigh portion, narrowing the stocking toward the ankle portions so that said ankle portion is substantially 60% of the original perimeter of the thigh portion, and knitting a foot portion.

2. A stocking formed of a yarn comprisingrayon, said stocking comprising a thigh portion, a knee portion, and acalf portion; said knee portion having a perimeter substantially of a perimeter of the thigh ortion; andsaidcalf por tion having a perimeter substantially of said perimeter of the thigh portion.

3.- A stocking formed of yarn comprising rayon, said stocking having a thigh portion, a kneeportion and a calf portion, and being adapted to be worn on a human leg having correspondingly located thigh, knee and calf portions, the perimeter of said knee portion of said stocking being less than the perimeter of the widest part of the calf portion thereof; narrowings in said thigh portion and widenings in said calf portion; and the yarn of said knee portion of said stocking being adapted to be stretched beyond the elastic limit thereof to a region of eflective elasticity greater than the original elastic limit of said yarn, when said stocking is put on said leg.

4. A stocking formed of yarn comprising rayon, said stocking having a thigh portion, a knee portion and a calf portion, and being adapted to be worn on a human leg having correspondingly located thigh, knee and calf portions, the perimeter of said knee portion of said stocking being less than the perimeter of the widest part of the calf portion thereof; narrowings in said thigh portion and widenings in said calf portion; and the yarn of said knee portion of said stocking being adapted to be stretched substantially beyond the realignment stage thereof, when said stocking is 'put on said leg.

5. A stocking formed of yarn comprising rayon, said stocking having a thigh portion, a knee portion and a calf portion, and being adapted to be worn on a human leg having correspondingly located thigh, knee and calf portions, the perimeter of said knee portion of said stocking being less than the perimeter of the widest part of the calf portion thereof; narrowings in said thigh portion and widening in said calf portion; and the yarn of said knee portion of said stocking being adapted to be stretchedbeyond the elastic limit thereof to a region of effective elasticity greater than the original elastic limit of said yarn, when the thigh, knee and calf portions of said stocking are worn respectively on the thigh, knee and calf portions of said human leg.

6. A stocking formed of yarn comprising rayon, said stocking having a thigh portion, a. knee portion and a calf portion, and being adapted to be worn on a human leg having correspondingly located thigh, knee and calf portions, the perimeter of said knee portion of said stocking being less than the perimeter of the widest part of the calf portion thereof; narrowings in said thigh portion and widenings in said calf portion; and the yarn of said knee portion of said stocking being adapted to be stretched substantially beyond the realignment stage thereof, when the thigh, knee and calf portions of said stocking are worn respectively on the thigh, knee and calf portions of said human leg.

EDWIN LOUIS SCHUBERT.

Images