US2353090A - Knit fabric and method of making the same - Google Patents

Description

y 1944- v s. R. SHELMIRE EI'IAL 2,353,090

KNIT FABRIC AND METHOD OF MAKING THE SAME Filed July 16, 1942 2 Sheets-Sheet 1 SINKER NEEDLE SINKER SINKER NEEDLE SINKER SINKER NEEDLE SINKER 111 l-llww NEEDLE NEEDLE NEEDLE v jizveizlanf a STANLEY R. SHE LMIRE PAUL COOPER i-hea'r ai-torne a' "Patented July-*4,

xrnrrnliarc ANDIME'IHOIIOF-MAKING ransom: Y

.stan ey a. Shelmire and Paul Cooper, -'N..H.',-assignors to Scott & Williams,lnorporated, Laconia, N. H a-c rporatlon ofMassaa 1 l 42,.- serial No. 451,195 (01. 66-202 17 Claims.

invention relates to fabrics and more particularly to a knitted fabric havingelasticity regardless of" whether or vnot it contains In this speciflcationtheword threadrLwill be used-in its broad sense so asto 'incfude not only ordinary,

"knitting yams but also such filaments as glass .thread, metal .wire, etc.

threads which are themselves elastic;

It *is' characteristic of the ilgentio'n that twokindsof threads are used and :that those two kinds of; threads differ in their-stiffness and flexing resilience.

In the accompanying drawings, we have'fllustrated onuantexaggerated.scale how our inven-m tion may be carried into eifectfiMerelyrfo'r illus- 'trative purposes to aid in the ready comprehension ofthe manner :of interknitting the threadsin interspersed courses, we have indicated in solid black the threads which are relatively stifl andresilient on fl ura'while the pliable threads "are indicated byoutline. I t

In the drawings: v I Figural is a diagram of the interlacing of the threads in a piece of fabric knitted in accord-,- ance with our invention, thefabric being shown atrest; the words needle" and "sinker" designating therelative positionsfof those elements in knitting the fabric;

Figurez is a similar diagram of the "samepiece" of fabric-partially stretched ina walewise direction; j 1

Figure 3 is asimilar diagram of the same piece ofl fabric'fully stretched in a walewise direction;

Figure 4 is a diagram of the interlacing of the threads in amodifled form of fabric in which'a pliable yarn is knit in :with the flexibly resilient yarn; while a Figure 5 is a diagram of the interlacing of the threads. of afabric made in accordance with our invention in whichthe course sequence of the threads is-diflerent from thatof Figures .1 to 4. Heretofore when it was desired to :make a our novel-fabric is not'dependent on the yarn beving "elastic" v-in the sense-that the yarn --can stretch longitudinallyand return to its normal "length when released. In manycases our fabric isepreferablymade from yarns which actually acannot stretch.

One of the threads It used in our .novel fabric must be relatively resilient on flexure, another thread in the fabric must be relatively pliable. It is the interactions! these twotypes 'of threads assembled in the manner to be described which produces I our elastic fabric. The flexibly resilientorspring-like thread maybe a -metal wire or strip such as a spring, cotton, rayon, a synthetlcthermoplastic yarn, regardless of whether it is elastic or inelastic, or it-may be any-other natural or synthetic yarn which is flexribly resilient and has the other necessarysquali- .ties hereinafter set forth. We havefound, for

example, that the -.synthetic thermoplastic .yarns formed of, vinylidene chloride r'esinsand known as Saran" Jand thpse formedof fibre-forming polmeric jamides'linown as Nylon are suitable .for use in our fabric,

The other or non-resilient yarn .of our novel fabric must be pliable and not too resistant to sliding at points where is contacts the other threads Itls preferably a fibrous thread. The

resilient and. non-resilient threads must be formed into loops in alternation. One factor in the production of the elasticity of the fabric is the drawing of a stitch or course of stitches of the resilient thread through a stitch or course of stitches of the pliable thread. Thus for example in Figures 1 to 3 we have shown a fabric which 10118 alternate course .Ii knit of the resilient thread, I0 is interspersed with one intermediate course 2! knit of the pliable thread 23. That is the preferable course arrangement, but it should knitted fabric which wasielastic, itwas .customary :to knit the fabric ofa ya-rn'which could itself stretch longitudinally and rely on thatelasticity-to give elasticity to the fabric. =Such-elastic yarns are principally rubber audits substitutes. All such yarnsare fragile andshort-lived, r r and under present war conditions are unobtairrablefor'civilian use. They are notv stifland'could not be used ordinarily to give our novel fabric. We have discovered that under certain conditions it is possible to make a knitted-fabric which is elastic, due, not to theiability of the threads-to stretch and return to their normal lengths, but to other factors. In other words the elasticity of teract to give elasticity to the fabric,

:be understood that the alternation need not be 1 x 1I I 1.

We. will now explain in what manner it is believed the resilient and non-resilient threadsin- When the resilient thread is knit it is constantly straining toward a straight position and the "esult is that the stitch formed of this resilient thread is qui te wide (see Fig.1). Thec'enter' or top ofthe needie wales is at the point marked needle. It will be observed in Fig. 1 that the legs of the needle wales are not vertical but separate 'or'divergefronl the tops of the wales at a wideangle so that the loops are opened up laterally, The threads do not assume this particular position will be observed that as the fabric is stretched walewise the fabric and the stitches become narrower and deeper. Thus the top portion 22 of the pliable thread 20 of the left-hand needle wale in Fig. 1 has become shorter, as shown at 1! in Fig. 2. The legs 24 of this needle wale in Fig. 1 are quite short, while in Fig. 2 they are distinctly longer, as shown at 25. The sinker wale II of this same yarn is also starting to shorten up slightly in Fig. 2. In Fig. 3 the top of the needle wale' is of only the width of ordinary fabric, as shown at 28, while the legs 30 of this needle wale in this figure are of th length of such legs-in normal fabric. i

The walewise stretch of the fabric pulls the legs ii of the'resilient needle wales together and causes the thread to bow out in a needle wale shape (Fig. 3) more usual than that of Figs. 1 and 2. 'It will be noted that the resilient thread iii in the stretched fabric (Fig. 3) is more bowed than the non-resilient thread 2|, which latter.

is more aptly described as sharply bent than resiliently bowed.

When the fabric is at rest it is necessary for the legs of the needle wales not to be in contact with each other. Unless this is true, there isno room for the stitch to bend resistively and thereby to have elasticity in the fabric. The pliable thread stitches should be knitted loosely to take full advantage of this effect.

If the resilient thread being used is a synthetic thermoplastic thread. it has been found further advantageous'to treat the fabric after it is knit. This treatment consists of pressure and heat. One purpose of the pressure is to improve the appearance of the fabric, but it has also been found when the fabric is subjected to heat and pressure, that the elasticity of the fabric is slightly increased. The purpose of the application of heat is to set the resilient thread in its new position. As is well known, when a synthetic thermoplastic yarn is set by heat, the shape or convolutions of the yarn at the time of heating become its norma1 or strain-free condition. Thereafter the thread resists any attempt to change it from that position instead of the straight position which was the normal or strain-free condition of the thread when it entered the knitting machine. As indicated, this combined pressure and setting of the thread by heat widens the fabric slightly and-increases the amount of its elasticity. It also seems to increase slightly the ability of the fabric to return to normal after stretch and its resistance to stretch.

The effect of this wide or opened-out course of stitches of the resilient thread on the non-re-- silient thread is to make the stitches of nonresilient thread shallow and wide. When drawn in the knitting machine this stitch of non-resillent thread at first was of normal length in a walewise direction. thread got away from the knitting point it tended to straighten, thus broadening the. sinker and needle wales of the non-resilient thread and decreasing the length of the stitch. v In this way the stitch of pliable thread becomes shallow and wide. When the threads are in the position shown in Fig. 1, the fabric is of its maximum width and minimum length and it has practically no elasticity in a coursewise direction. This is its normal or relaxed condition. However, the

fabric has a large amount of stretch in a walewise direction. It will also be noted that the stitches of resilient thread are shallower than if they had not moved after'being' knitted. Thus the interspersing of the resilient and non-resilient threads during the knitting produces a wide fab ric but one. that has shallow stitches and is short in a walewise direction.

Fr om the description thus far given it will be obvious that it is immaterial whether the resilient thread is also elastic in its length or not--at least as far as concerns the elasticity of the fabric due to the interspersing of the resilient and nonresilient stitches in the knitted fabric.

The above-mentioned changes in shape of the stitches of non-resilient thread necessitate a sliding of the pliable thread 20 on the resilient thread i0. There also is sliding of the resilient thread on the pliable thread. It has been found that when both resilient and non-resilient threads have a large number of filaments in them, the sliding is so interfered with that the elastic character. of the fabric is largely lost. For this reason we have found it advisable to make the resilient thread of very few filaments and preferably a monoiilament and of large cross-section, such as is found inplastic yarns. The large cross-section presumably also plays its part in the stiffness and flexible resilience of the yarn. In this form the synthetic thermoplastic threads known as Saran" and "Nylon" are smooth and slide well. Any combination of threads which permits easy sliding of the threads on each other will be satisfactory for our fabric, provided the contrasting characteristics as to resilience and pliability are present. However, if the fabric is to be used on or adjacent to human flesh, it probably will be inadvisable to use a thread like piano wire because I of the danger of a broken thread causing a scratch.

We have discovered that our elastic effect in the fabric can be obtained to a modified extent if groups of one, two or three courses of resilient or non-resilient thread are together. Beyond that point most of the effect is lost. The more courses of non-resilient thread between the resilient thread, the less elasticity, although under certain conditions two courses may give more stretch than one. The interlacing of one resilient loop withanother does only a little to increase the resilience of the fabric. While the interlacing of one stitch of non-resilient thread with another non-resilient thread increases the stretch of the fabric slightly. it also tends to reduce the ability of the fabric to return to its original size when released. Such a construction is shown in Fig. 5,

where the alternation is two courses of nonresilient yarn 20 and one of resilient yarn i0.

. This gives more of the pliable thread to be pulled As soon as the resilient by the resilient thread.

If desired, the harsnfeeling of some of the resilient thread available for use in our fabric can be largely eliminated by knitting a rayon or other softer thread 40 with the resilient thread ll (Fig. 4). The inelastic thread is caused to cover the elastic by the method set forth in the John Lawson Patent 2,009,361, dated July 23,

1935. The covering thread 40 can be the same as the pliable fibrous thread 20 or not, as desired.

If desired, the fabric can be knit in a knitting machine where there'are two sinkers between two adjacent needles, as indicated for example, I in Fig. i. This has the effect of producing along sinker wale and increasing the extent to which the fabric can be stretched in a walewise'direction. Similarly, any lengthening of the needle wale would tend to increasethe separation of the legs of the needle Wale. .j

and non-resilient thread, said resilient thread, tending to straighten out, forms stitches later allyopened out and contracts the fabric in a a walewise direction in which thethreads in ah 'tern'ate courses have stiffness and resilience to If the elasticity of the fabric exhibits fatigue,

the fabric can be washed and reset by heat and pressure, whereupon it resumes all its original elasticity. and strength.

'weclaimz' l. Knitted fabric comprising threads of different character as to stiffness] and resilience,

in which groups of one to. three courses containing a relativelystiif-but flexibly resilient thread are alternate repeatedly'withgroups of one to three courses containing a relatively pliable thread, said flexibly resilient thread being pres-- en't'in stitches opened out whereby said stitches contract the fabric in a walewise direction, giving the fabric elasticity in that direction. 2. Fabric knit of groups of from onewto three courses of a stifl but flexibly resilientthread interknit in repeated. succession withgroups .of

from one to three courses of a pliable thread,

- the resilience ofv the stifljthread opening the stitches of said thread laterally 'andcontracting -the stitches walewise and making the. fabricelastic in that direction.

3. In weft knit fabric in which threads of dif- 'j walewise direction, thereby giving the ,fabric elasticity in thatdirection, g

7. Weft knit fabric havingje'xtra elasticity in "bending. and the threads in the. intermediate courses have less resilience to bending, said more resilient stitches tending to straighten cut, openq '8. Inaw'eft knit fabric containing alternate courses in which threadsare present having diffent characteristics, the combination ofa thermoplastic' thread having stiffness and flexible resilience in one course' and a pliable thread in the other course, said two threads being interknit, the

' thermoplastic threadbeing set with'its stitches laterally opened'out' whereby on walewise ten- "sion the legs of the resilient needle wales will come together and the stitches of the more pliable 1 thread interlaced, throughout those legs become narrower and longer and the fabric's'tretches in the walewisedirection'j 9. Knitted fabric composed of alternate courses containing at least pliable thread in, one course ferent characteristicsare present for the purpose of giving elasticity to the fabric, a, relatively stiff being present in stitches laterally opened out,

whereby the flexibly resilient thread permits the and flexibly resilient thread knit in alternate courses, in combination with a relatively pliable thread knit in the intermediate courses, the resilient thread opening its stitches laterally and tending to straighten out and thereby shorten both resihent and pliable stitches in the walewise direction, contracting the fabric and giving it elasticity in that direction.

4. Weft knit fabric in which relative differences in stifiness and flexing resilience of thread are used to give elasticity to the fabric, there being a. relatively stiff and flexibly resilient thread knit in alternate courses, in combination with a relatively pliable thread in the intermediate courses, the resilient thread widening its own stitches and those of the pliable thread, shortening the fabric and making it elastic in a walewise direction. v

5. Weft knit fabric in which relative differences in stiffness and flexing resilience of threads are used to give elasticity to the fabric, the fabric at rest containing one or two courses of a relatively stiff and figxibly resilient thread formed in stitches with the legs of the needle wales bent apart due to the resilience of the thread, in combination with a relatively pliable thread in one or two courses interspersed with the resilient thread, the stitches of the pliable thread making wide and shallow stitches due to the spreading of the legs of the needle wales of the resilient thread, said legs being pulled together against the resilient power of that thread when the fabric is stretched in a, walewise direction, so that the fabric is elastic in that direction.

6. Knitted fabric composed of alternate courses of threads some of which have diflerent .characteristics arranged in courses in repeated succession, there being present in one type of course a stiff and flexibly resilient thread of a smoothness permitting the thread interlaced with it from adjacent courses to slide thereon, the intermediate courses containing a more pliable and a stiff and flexibly resilient thermoplastic thread in the other. said thermoplastic thread fabric to be stretched walewise and its resilience contracts the fabric'again when the tension is released.

10. Knitted fabric composed of altemate courses containing at least pliable fibrous thread in one course and a stiff. and flexibly resilient thermoplastic monofllament thread of large cross-section in the other, said thermoplastic thread being present in stitches laterally opened out, whereby the flexibly resilient thread permits the fabric to be stretched walewise and its resilience contracts the fabric again when the tension is released.

11. Knitted fabric having extra elasticity in a walewise direction composed of alternate courses in which there are present stiff and flexibly resilient thread in one course and pliable thread in the other, the stitches in which these threads are presentbeing interlaced with each other in alternation ins walewise direction, the stitches of the resilient thread being laterally opened out thereby forcing all the stitches of the fabric to be wide and shallow, whereby the tendency of the resilient thread to straighten out provides elasticity in the walewise direction in the fabric.

12. A method of making weft knit fabric having extra elasticity in a walewise direction, composed of knitting one or more courses of a relatively pliable and flexibly non-resilient fibrous thread in repeated succession to one or more courses of a thermoplastic thread resilient to bending, allowing the resilient thread to pull the non-resilient stitches into a wide shallow shape and setting the thermoplastic thread while the fabric is in this condition.

13. In a method of making knitted fabric having extra, elasticity in a walewise direction, the steps of knitting alternate courses of relatively still and flexibly resilient thermoplastic thread 4 auaooo monofllament thread. in comband relatively pliable threadwhilefforminz extra width sinker wales 'and allowing the resilience of the thermoplasticthread to hold "pliable thread in shallow wide shape, and thereafter letting thethermoplasticthread in thiesllzhtly bent position, whereby tension Qnthefabric'ina walewise direction tends -=to :qpull the less of the thermoplastic stitches into more normal parallel formation against aree'ilienoe "of idle plastic thread with "resultant extension :of the fabric walewi se. p

14. In a method :ormakingfknitted'ifabric having extra elasticity in a walewise "direction, steps of knitting "courses or -.relatively :stm wand flexibly "resilient thermoplastic in 1 alternation with the knitting "of *comseeof pliable "thread "while allowing "etitches :of the latter thread to ibe formed -looeelyfithue zpermitting the legs of the' needle males .of the resilient thread to spring apart and iform thread into shallow ".wide stitches, whereby tension on thefabrlcfln I atwalewlse zrlirection xtenfll to pull the legs of the'-needle==.wales of :thereoilient thread into morezi parallel formation against the resilience "of the --thread, therebya perniittin:

iniore'pliable covering thread, and the-alternate coureerhavin: inthem a relatively usable-thread knit loocely, ieaidreailient thread 'beinz'apreeent in "cfltchea laterally opened out wherebythe reeilient threed holda :allthe stitches of the room in awideehallow I shape and reds. :reailientlypeiforts'tortretch thefabricin a'waledirection, the monmlament and pliable *thmdl illldihl on'uch other to neceschaneee in the shapes of thertitchea as the fabric intretche'd and relaxed;

J16. i-Knitted fabric composed of alternate woounercontainin: atleast pliable thread in one a Barm thread in the other, paid bein: mom out, whereby permit:

@the arm to be -.etretched walewile and it: re-

m'illenceoontracta thefabric azainewhen the (ten- :Ieiontia released.

.117. ine 'fabric'amitor.relatively pliable thread.

arelatively 'stlfl a'andiilexiblyresilient thread knit :in the aalternate "courses. laid resilient thread the fabric to stretch/lava walewlse :directionan'd 4 return to its a normal length when the tenalonvis released.

15. Weft knit fabric composed \of alternate courses of threads of -diiferentncharacteristica, alternate courses being -knltted -Iof re'lativelyxstifl.

m lts stitches laterally and thereby ghorteninz-both resilient and pliable thread stitches in 'thewalewise direction to contract the fabric and ,give I the fabric elasticity .in the walewiae direc- BTANLIYJR. s. mp1. .coorm

Images