US2295794A - Method of knitting run-resistant fabric - Google Patents

Description

c. A. KAUFMAN METHOD OF KN ITTING RUN-RESISTANT FABRIC Sept. 15; 1942.

3 Sheets-Sheet l Original Filed June VQVU . arromevs c. A. KAUFMAN METHOD OF KNITTING RUN-RESI STANT 'FAiBRIC Sept. 15, 1942.

Original Filed June 7, 1941 5 Sheets-$heet s mvsmola 6 00/0701:

I (bar/es c9.

nated a, that which appears in courses- Patented Sept. 15, 1942 Charles August Kaufman, New York,l N. Y.

Original application June '2, 1941, Serial No. 391,094. Divided and um application April 16, I 1942, Sel'ial No. 439,110

14 Claims.

This invention relates to the production of weft knit fabrics so constructed as to resist or prevent runs which ordinarily result from the breaking of a yarn in plain weft knit fabric. 'The invention may find its most general application to theproduction of hosiery fabric upon knitting machines of the Cotton type.

The principal object of the invention is to pro- (cl. sis-st) is designated b, and those which appear in the upwardly from the further side of the fabric' vide a method whereby run-resistant fabric of the type hereinafter described may be produced practicably upon available machines suitably modified to cause the usual knitting instrumentalities and accessory devices to function in cooperation with each other for the production of such fabric;

For purposes of illustration a preferred embodimentof -my invention will be hereinafter described, and in order that the invention may be clearly understood I shall also describe herein the novel run-resistant fabric which is the subject matter of my co-pendlng application Serial No. 397,094,1iled June I, 1941. The present'application is a division of my said co-pendlng application. 1

In the accompanying drawings, Figure 1 is a fragmentary plan view of the reverse side or back of a piece of knitted fabric which may be produced by the present invention. showing the upper side of the fabric asit would appear on a knitting machine when viewed from the front thereof. 7

Figures 2 to inclusive are tic elevatlons. imperspective. illustrating certain steps in a preferred embodiment of the present invention by which the fabric of Figure 1 may be Produced.

Referring to Figure 1 of the drawings, a fragment'of weft knitted fabric is shown wherein the courses of the basic knitted structure, in the order in which they have been formed. are numbered I to I inclusive. The needle wales are numbered II to II inclusive. The wales formed by the sinkers and dividers which, for convenience, will 7 alibe called sinker wales, are numbered II to inclusive. Only half of the wales I. and Il are shown. The several lengths of yarn forming the loops of courses I to 8 respectively are desig-,

.nated by letters A to E inclusive. The knitted structure thus far described is'the usual plain knit fabric which may be referred to as the basic 7 Froman remaining courses are designated c and d respectively. 4

examination of courses I and-2 beginning at the lower left hand cornerof Figure 1, it will be observed that the binder yarn a extends through the needle loop of yarn A in wale Ill, over one leg of this loop, and over and loosely around one leg of the needle loop of yarn A in wale II, returning on the under side of the fabric under the point of engagement of yarn A and yarn B at the junction of courses I and 2. Thereafter the binder yarn again comes to the upper side of the fabric through the sinker loop of yarn B in wale 20, only half of which is shown, and

then passes loosely over the two legs of the needle loop of yarn B in wale lll'and downwar ly through the sinker loop of this yarn in wale II. The binder yarn a then upwardly through theneedleloopofyamAinwale-II.anditspo-- sition with respect to the remaining loops of basic yarn in courses I and I is respectively the same as heretofore described with respect to the preceding loops of these two courses.

A further examination of Figure 1 reveals that the described structure is duplicated with respect yarnsnandcincoursesland 3,exceptfor the fact that the direction of the loops of binder yarn b are reversed laterally with respect v to the loops of'binder yarn 1:. Starting at the right marginofthe e lmitwillbeseenthatthe binder yarn b extends upwardly through the needle loop of yarnB in wale I3, across the left leg of this loop and the right leg of the adjoining needle loop in wale I2, there going down through theneedleloopofyarnBinwale I2, looselyengagingtherightlegof thisneedle loopandreturning on the further side of the fabric to, and coming upwardly through, the sinker loop of yarn C in wale 2|, only half ofwhich is shown. Thereafter the binder yarn b passes loosely over both legs of the needle loop of yarn C in wale I3, downthrough the sinker loop of this yarn in wale 23 and upwardly through the needle loop of yarn B in wale I2. after which the relation of thebinderyarntothesuoceedingloopsofbasic yarnin courses 2 and I is a repetition of that heretofore describedwith respect tothe preceding ops;

Figure 1 shows the described structure of the binder yarn a in connection with the yarns A and B forming courses I and 2, repeated by the binder yarn-c and the yarns C and D forming a and! oolrrseslandflandthestructuredescribedwith respect to binder yarn b and yarns B and C in courses 2 and 3, repeated by binder yarn d in connection with yarns D and E in courses 4 and 5.

It will be seen that this structure provides a positive engagement of every needle and every sinker loop by a binder yarn so that upon the breaking of any loop ofthe basic knitted fabric, whether said. rupture occurs in a needle loop or a sinker loop, a run will be checked regardless of whether it occurs in a needle wale or in a sinker wale. For example, let it be assumed that the needle loop of yarn C in wale I2 is broken. This A would normally release the needle loop of yarn B in wale l2 and start a run in the direction of course I but in the described structure 'the needle loop of yarn B in wale l2 will be held from pulling through the next succeeding needle loop by the binder yarn b where it passes through this needle loop in course 2 and also where it passes around the right leg of this needle loop. in course 2.

By way of further example, let it be assumed that the sinker loop of yarn B in sinker wale 22 becomes broken. This would normally release the sinker loop of yarn C in wale 22 and start a run in the direction of course 5, but the binder yarn b passes through the sinkerloop of yarn C in course 3 and also engages the left leg of this sinker loop in course 3, thereby holding the unbroken loop and preventing it from releasing the next succeeding sinker loop in wale 22 of course 4.

It will be observed that the binder yarn has yarn at intervals. For example, a structure like that of Figure 1 except for the omission of the binder yarns b and d, could be produced by the present invention and would have desirable runresisting properties. Therein the binder yarn would stop a run in either direction at a point in the course next following the course in which a break occurred, if the break occurred in a loop not engaged by a binder yarn, or in the second succeeding course, if the break occurred in a loop engaged by a binder yarn. In some instances it might even be desirable to produce by the present invention a fabric wherein the insertion of the binder yarn is separated by more than one intervening course of the basic fabric, or the insertion of binder yarns is confined to selected pairs of courses in some particular part of the fabric. Wherever the binder yarn is thus inserted the direction of the binder loops, which is the same throughout any one pair of courses, may be predetermined as desired.

The loops of the binder yarn a are shown in Figure 1 extending diagonally to the right from course 2 to course I, and those of the yarn b diagonally to the left from course 3 to course 2. The same alternation of direction is continued v regularly throughout succeeding courses of the been introduced into the basic fabric so that it 85 even removed without disrupting the basic fabric.

The binder yarn is interlooped with the basic yarn without increasing the length of the basic fabric or necessarily distorting or displacing any of the loops of the basic yarn.

Examining the structure of Figure 1 with particular reference to the effect of the binder yarn upon elasticity or stretchability, it will be understood that as the fabric is stretched in wale-wise direction each course becomes wider by an increase in length of the vertical components of the basic knitted loops, and that the binder yarn will not restrain this'widening of the courses because it extends across the fabric in approximately course-wise direction, with the loops of the binder yarn in relatively loose engagement with the loops of the basic knitted fabric in two immediately adjacent courses. When the fabric is stretched in course-wise direction the wales of the fabric become wider by an increase in. length of the horizontal components of the basic knitted loops. The binder yarn will not unduly restrain the widening of the wales because it is relatively loosely engaged with the loops of the basic knitted fabric and allows sufiicient robbing movement or interplay of the loops of the basic yarn to take placeas the wales widen. The loops of the binder yarn are free to straighten out and assume a position more nearly horizontal than that shown in Figure 1, and thus increase the effective length of the binder yarn between the margins fabric shown, but these loops may all extend in the same direction if desired. For example, if 30.

the yarns B, b, D and d were not present in Figure 1, and the yarns A, C and E were directly interlooped with each other to form the basic knitted fabric, with binder yarns a and 0' engaged therewith in the manner shown, a structure would be provided in which the loops of binder yarn all extended diagonally in the same direction.

The fabric shown in Figure 1 may be knitted on a flat knitting machine of the previously mentioned type from one cone of yarn to form the basic fabric, and the same yarn from the same cone may be interlooped upon itself in the manner hereinafter described to form the binder yarn. In other words, a single yarn may be laid back and forth and, in the manner hereinafter described, it may be formed into basic loops or be laid as a binder yarn after every course or after any selected number of courses of the basic fabric, as will readily be understood.

Two or more yarns from different cones may be used, particularly if it is desired to employ as a binder a yarn differing from the yarn of the basic knitted fabric, as for example, a somewhat thinner or finer yarn. When employing a different binder yarn, it is practicable to draw the basic yarn for alternate courses from two separate cones and the binder yarn from a third cone. Two of the yarns may be alike to form the basic fabric and the third may be the yarn selected to form the binder. The three yarns from different cones may then be inserted in regular alternation as in the well known three carrier knitting operation, the binder yarn being inserted after every second course of the basic yarn. When the three yarns from different cones have been thus laid and interlooped as hereinafter described, a structure difiering from that shown in Figure 1 will result. The two yarns which may be alike will appear as the basic fabric yarns A and B respectively, and again as yarns C and D of Figure 1, while the other yarn will appear as binder yarn a and again as binder yarn c of Figure 1. Operating in this manner the finished fabric will not contain any yarns corresponding to binder yarns b and d of Figure 1, but only binder yarns corresponding to a and c' which will have been introduced after every second course of the basic yarn. Such a structure wherein all yarns arealike may also be produced advantageously from three cones of yarn by the three carrier operation Just described.

The foregoing and other arrangements of a thinner or different binder yarn with relation to the basic yam may be efiected without the use of the well known idle course operation. If idle course operation is employed and the requisite number of carriers are available, two yarns can be laid successively from the same side of the machine and therefore a thinner or different yarn or any one of a group of yarns, may be introduced as a binder whenever desired, and any one of another group of yarns may be introduced to form the basic fabric. Proceeding in this manner a structure, as for example that shown in Figure 1, could beproduced wherein the binder yarns of to d inclusive may be drawn from one or more cones of binder yarn, and the basic yarns A to E inclusive may also be drawnfrom one or more cones of basic yarn.

Having thus described certain run-resisting fabrics which may be produced according to the present invention, there will now be described, by

particular reference to Figures 2 to '7 inclusive, a practicable and illustrative sequence. of operation of the usual knitting instrumentalities which embodies the present invention and. by which such fabric may be formed. Inasmuch as it is intended that these operations should be carried out upon flat knitting machines 'of well known types, as for example upon the well known Reading machine, it is unnecessary to show all of the standard parts which cooperate witheaeh other during these operations, and theshowing is limited to a few needles of the usual type and a few corresponding transfer points of the usual type; it being understood that in practice a transfer point is provided for each needle mounted in the needle bar, except as hereinafter pointed out.

the ordinary knitting cycle, or the knitting mating machine may be arranged to bring into operation any of the three groups of cams when desired. Each cam of the second and third group of cams may be contoured and arranged in. respect to each other so as to permit the knitting instrumentalities controlled by each group respecti-vely, to functionsuccessively and in synchronized relation in-the manner hereinafter described.

Referring to Figure 2, a series of needla N to N inclusive, of .the usual spring beard type are shown diagrammatically. Yarn A, which is one of those forming the basic knitted fabric, is looped upon the needles as it would appear at the be inning of the sequence of operations about to be described.

Figure 3 also shows the needles and a corresponding series of transfer points P to P of the usual type. Yam 0', which'is intended to become a binder yarn, is shown as it would appear after having been laid across the bank of needles and indented and measured in loose course formation between the needles by the sinkers and dividers which are assumed to be'present but are not shown. It is not intended that the exact extent of the indentation and measurement 'of the yarn u should be indicated by Figure 3 or any subsequent figure of the drawings; the illusbe measured and indented so that there will be .enough yarn between adjacent needles to permit the transfer ofbasic loops as hereinafter de- The needles and transfer'points are operated in the'manner hereinafter described to bring about the interlooping of the binder yarn or yarns with the yarn or yarns forming the basic knitted fab ric. 1

It is well known that flat knitting machines of the type mentioned are provided with a main cam shaft mounting contoured cams which'actuate the various knitting instrumentalities, and that such cams for each of the various knitting instmmentalities are so shaped and synchronized as to cause their respective knitting instrumentalities to function in the usual predetermined and specified manners. One group of cams is usually laid 'out to actuate the knitting instrumentalities in; respect to their functions in the ordinary knitting cycle, whereas another group of cams, mounted on the main cam shaft directly adjacent to the first group, is usually laid out to function during lace, transfer or narrowing operations. Either group of cams may be brought into operating position through the shogging scribed and to allow the binder yarn to lie relatheir l osely within the finished basic fabric without distorting or straining the normal loops of that fabric. In the fabric illustrated in Figure 1 it would be observed that a greater length of yarn is required to form each loop in the binder yarn than is required'to form each loop of the basic fabric. Such a greater length of the binder yarn a may be measured and indented in. the well known maner'in which a yarn is measured and indented whenever a loose course is desired.

After the binder yarn a has been laid across the bank of needles and measured and indented as previously stated, the sinkers and dividers will hold this yarn against the shanks of the needles in position to be grasped by the hooks of the needles. The needles will now descend and when the hooks have grasped the yarn a the transfer points P and the beards of the needles will be. brought together in the custom-' any manner inorder to close the beards of the descending needles before they reach the previously formed loops of the yarn A which are resting in the usual manner upon the knocking .over bits, assumed'to be present but not shown. This step is indicated in Figure 4 wherein 'it will be observed that the beard of each needle is closed around the binder yarn a.

As the needles and points descend together moved upward with the loops of the yarn A held upon the points P, while the binder yarn a is still held in the hooks of theneedles.

The loops of yarn A are on points P and may be simultaneously transferred in the same direction from one needle to the next, either to the left or right as desired, while each loop of the binder yarn a continues to be held by the hook of the needle upon which it was formed. The loops of yarn A may be transferred despite the fact that a loop of yarn a passes through each needle loop of yarn A, It is important that a suflicient length of binder yarn a shall have been measured to permit this transfer to take place. Thus in Figure 6 the loops of yarn A are en-v gaged by the points P during the transfer of each of these loops from the needle upon which it'was formed to the needle next adjoining on the right. The relative movement of the points and needles is such that each loop of the basic fabric, except possibly the outermost loop, is lifted, moved to the right, and placed upon the next adjacent needle over a loop of yarn a still held by the needle upon which it was formed. The transferring is thereupon completed by movement of the points P and the needles N as in the usual transfer cycle. This will leave the several loops of yarns A and a on the needles as shown in Figure '7; the-loops of yarn a being held on their original needles respectively while the loops of yarn A are held on the needles next adjacent to the right above the loops of yarn a". In this figure an additional needle N not heretofore illustrated, is shown in engagement with the loop of the basic knitted fabric transferred from needle N. This figure also shows at the left in dotted lines another loop which, it may be assumed, has been transferred to the needle N from a needle next adjoining it on the left by a transfer point now shown in dotted lines above this needle.

In order that the loop of yarn A at the edge of the fabric toward which the transfer is to take lace, may not be cast off, the yarn A may be so laid that aloop will not be formed on that outermost needle of the bank of needles. Another way of preventing such casting oil is to arrange the transfer points so that while a loop may be formed on the outermost needle, no point will be provided to remove that loop during the transferring operation.

There are now two loops on each needle shown in Figure 7, namely, one loop of the yarn A over one loop of the yarn a but in no case, except possibly at the edge of the fabric, are two loops of the basic yarn placed on the same needle. It will be observed that the yarn a has been brought into the position shown in Figure 7 without increasing the length of the fabric being knitted, andthat it lies within the course formed by yarn A without distorting any of the loops of the basic fabric. The loops of the yarn a at this stage lie generally across the fabric, extending downwardy through each needle, loop of the basic fabric, and around the shank of an adjacent needle. The needles with the two yarns A and a thereon are now in such position that the next course of the basic fabric may be knitted by the usual sequence of operations while the transfer poinm remain inactive and out of contact with the needles.

With the needles in raised position and the yarns A and a thereon as shown in Figure 7, another yarn is laid, indented and measured in the usual manner. As the normal operation of the machine proceeds, the newly laid yarn will be drawn down through the loops of yarns A and a, after which these loops will be cast off the needles by the normal action of the usual instrumentalities and a single course of new undistorted basic loops will thus be added to the fabric.

After the knitting of the last mentioned course, the fabric will take the form shown in Figure 1, assuming that the yarns A, a and B are the yarns which have been laid, interlooped and knitted as just described, and that the remainder of the fabric has not yet been knitted.

If it is desired to introduce the binder yarn b as shown in Figure 1, the sequence of operations heretofore described wil"be repeated except that when the loops of yarn B are held by the points P, the points will be shifted to the left and will transfer the loops of the basic fabric to the left instead of to the right. This will have the effect of reversing the direction of the loops of the binder yarn shown in Figure '7. As previously pointed out, the transfer is accomplished without distorting the loops of the basic fabric. Then when-the next course of the basic fabric, as for example yarn C of Figure l, is knitted into the fabric by the usual sequence of operations, the binder yarn b will appear in the fabric as shown'in Figure 1.

If it is desired to produce a fabric in which the loops of binder yarns all lie in the same direction in every pair of courses, or in selected pairs of courses of the basic fabric, the points P will transfer loops of each such course of the basic yarn in the samedirection after each binder yarn has been laid. For example, if the transferring operation first described is repeated, the yarn b will take a position in the finished fabric in relation to yarns B and C which is in all respects a duplication of the position of yarn a in relation to yarns A and B. If it is not desired to have the binder yarn in every pair of courses, the knitting of several courses of yarn of the basic fabric in the regular manner may follow the introduction of each binder yarn.

It will be understood that the invention may be variously modified and embodied within the scope of the subjoined claims.

I claim as my invention:

1. The method of producing run resisting knitted fabric which comprises forming a course of plain knit undistorted basic yarn loops upon selected adjoining needles of a bank of needles, indenting a. binder yarn between each said selected needle and the next adjoining selected needle, drawing the needle engaged portion of each said binder yarn indentation through a corresponding basic yarn loop without casting on any of the latter, transferring every said basic yarn loop without distortion from the needle upon which it was formed to the next adjoining needle while retaining all the binder yarn loops upon the needles, thereby forming s-shaped loops of binder yarn within the said course or basic yarn loops, then knitting another course of basic yarn loops into each of the previously formed pairs of basic yarn and binder yarn loops, again indenting a binder yarn as aforesaid and continuing the described cycle of procedure.

2. The method of producing run-resisting knitted fabric according to claim 1 wherein the transfer of basic yarn loops is effected in alternate directions in successive repetitions of the described cycle of procedure.

3. The method of producing run-resisting knitted fabric according to claim [wherein at leastone additional course of basic yarn loops is knitted into the preceding course of basic yarn loops after each repetition of the described cycle of procedure.

4. The method of producing run-resisting knitted fabric which comprises forming a course of basic yarn upon selected adjoining needles of a bank of needles and thereafter carrying out the following steps in regular repetition, forming a binder yarn indentation between each said selected needle and the next adjoining selected needle, drawing the needle engagedportion of each said binder yarn indentation through a correspond ng basic yarn loop while the basic yarn loops are held from casting off by transfer points cooperating respectively with each selected needie, transferring each basic yarn loop from one needle to the next adjoining needle while retaining the needle engaged portion of each binder yarn indentation on the needles and thereby forming loops of binder yarn, forming another course of basic yarn upon the needles and drawing a loop thereof through each pair of previously formed basic yarn and binder yarn loops.

5. The method of producing run-resisting knitted fabric according to claim 4 wherein the basic yarn loops are transferred in alternate directions in'successive transferring operations.

6. The method of producing run-resisting knitted fabric according to claim 4 wherein at least one additional course of basic yarn is formed upon the bank of needles and knitted into the preceding course of basic yarn after each repetitionof the steps of procedure described.

7. The method of producing run-resisting knitted fabric which comprises forming a course least one additional plain knit course is knitted into the fabric between each repetition of the described cycle of procedure.

10. The method of producing run-resisting knitted fabric which comprises forming a course of plain knit undistorted basic yarn loops upon selected adjoining needles of a bank of needles, indenting a binder yarn between each said selected needle and the next adjoining selected needle, drawing the needle engaged portion of each said binder yarn indentation through a corresponding basic yarn loop without casting off any of the latter, removing from engagement with the needles the previously knitted fabric in its entirety excepting only the needle engaged portions of the binder yarn, moving the said fabric laterally'of the bank of needles to an extent equal to the distance between adjoining needle centers while the binder yarn is still engaged by the needles, then replacing the fabric upon the needles and thereby forming loops of binder yarn within the said course of basic yarn loops, then knitting another course of basic yarn loops into each of the previously formed pairs of basic yarn and binder yarn loops, again indenting a binder yarn as aforesaid and continuing the described cycle of procedure.

11. The method of producing run-resisting knitted fabric according to claim 10, wherein the entire fabric, except the needle engaged portions of the binder yarn, is moved laterally of the bank of needles in alternate directions in successive repetitions of the described cycle of of yamloops upon selected adjoining needles each indentation of binder yarn upon the needles and thereby forming loops from said indentations, forming another course of yarn loops with each loop thereof drawn through each pair of loops previously forined as aforesaid, again forming binder yarn indentations corresponding to the indentations first above mentioned and continuing the described cycle of procedure.

8. The method of producing run-resisting knitted fabric according to claim 7, wherein the course of yarn loops first mentioned is transferred in alternate directions in successive transferring operations.

procedure.

12. The method of producing run-resisting knitted fabric according to claim 10, wherein at least one additional course of basic yarn loops is knitted into the preceding course of basic yarn loops after each repetition of the described cycle of procedure.

13. The method of producing run-resisting knitted fabric according to claim 10 wherein at least one additional course of basic yarn loops is knitted into the preceding course of basic yarn loops after each repetition of the described cycle of procedure, and wherein the entire fabric, except the needle engaged portions of thebinder yarn, is moved laterally of the bank of needles in alternate directions in successive repetitions of the described cycle of procedure.

14. The method of producing run-resisting knitted fabric according to claim 10 wherein one additional course of basic yarn loops is knitted into the preceding course of basic yarn loops after each repetition of the described cycle of procedure, and wherein the binder yarn is drawn from one source and the basic yarn for successive courses is drawn alternately from two other sources.

9. The method of producing run-resisting CHARLES A. KAUFMAN. knitted fabric according to claim 7, wherein at

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