US3430462A - Method and apparatus for knitting run-resistant fabric - Google Patents

Description

March 4, 1969 NEBELH ETAL 3,430,452

METHOD AND APPARATUS FOR KNITTING RUN-RESISTANT FABRIC Filed March 31, 1967 Sheet of 5 '1 a n r l HQ I i s} P h 2 N1 N2 IFF N2 N1 N x FIG. 3

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BY ERHARD MAX NEBEL @JI M ATTORNEYS MAX BRUNO NEBEL Mar h 4, 1969 M. B. NEBEL ETAL 3 430 4 2 METHOD AND APPARATUS FOR KNITTING RUN-RESISTANT FABRIC Sheet Filed March 31, 1967 Elly.

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March 4, 1969 BI NEBEL ET L METHOD AND APPARATUS FOR KNITTING RUN-RESISTANT FABRIC Sheet Filed March 31, 1967 JNVENTOR.

MAX BRUNO NEBEL I By ERHARD MAX NEBEL F! v M ATTO R N EYS United States Patent 3,430,462 METHOD AND APPARATUS FOR KNITTING RUN-RESISTANT FABRIC Max Bruno Nebel and Erhard Max Nebel, Wiesbaden,

Germany, assignors to Hanes Corporation, a corporation of North Carolina Division and continuation-in-part of application Ser. No. 347,735, Feb. 27, 1964, now Patent No. 3,319,440, dated May 16, 1967. This application Mar. 31, 1967, Ser. No. 627,350 US. Cl. 66-42 22 Claims Int. Cl. D04b 15/80, 9/38 ABSTRACT OF THE DISCLOSURE Method and apparatus for knitting run-resistant fabric from at least two yarns, which alternate walewise of the fabric, and in which one yarn is formed into alternate plain stitches in selected wales and into floats in the intervening wales, and in which the next succeeding yarn is formed into plain stitches in the intervening wales and into elongated loops in the selected wales, with the elongated loops being doubled with the next succeeding plain stitches in the selected wales throughout the fabric.

This application comprises a division and a continuation-in-part of U .8. Patent No. 3,319,440, granted May 16, 1967.

The primary object of this invention is to provide new and useful methods and apparatus for producing new and useful run-resistant knitted fabrics, for use in ladies sheer hosiery and the like.

Another object is to provide a novel method of producing such run-resistant fabric on a conventional multifeed circular knitting machine.

A further object is to provide new and improved apparatus for producing such circular knit fabric on a knitting machine having two separate yarn feeds, or multiples thereof.

Other objects of this invention will become apparent when the following description thereof is read with reference to the accompanying drawings in which:

FIG. 1 illustrates diagrammatically the inside of a preferred form of the run-resistant fabric of this invention;

FIG. 2 comprises a development of the camming for a two feed circular knitting machine for making the fabric of FIG. 1;

FIGS. 2a, 2b, 2c, 2d and 2x are enlarged fragmentary views in side elevation illustrating the operating positions of the needles and sinkers at diiferent steps of the method of the invention;

FIG. 3 is an enlarged fragmentary schematic view, taken from the inside of the needle cylinder, showing the needles and sinkers of the machine at one of the yarn feeds thereof;

FIG. 4 is a fragmentary schematic view in top plan showing the sinker cams and the relative positions of the sinkers of the machine; and

FIG. 5 is a fragmentary view in elevation showing a preferred type of needle used in the practice of this invention.

The run-resistant fabric shown diagrammatically in FIG. 1 is knit of yarns a and b which alternate walewise of the fabric. Yarn a is formed into alternate plain stitches A and elongated loops S, while yarn b is formed into plain stitches B alternating with floats H. In each instance, the yarn a is succeeded Wale-wise immediately by yarn b in the fabric, so that the plain stitches B of yarn b anchor the plain stitches A of the preceding yarn a. By reason of this construction, each course of the fabric may be said to consist of the two yarns a and b.

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Preferably, the plain knit stitches A of each pair of adjacent or successive course-Wise extending yarns a are staggered Wale-wise of the fabric by one wale. Thus, the lowermost yarn a of FIG. 1 is formed into elongated loops S in wales 1 and into plain knit stitches A in Wales 2, whereas the next succeeding yarn a is formed into elongated loops S in wales 2 and into plain k-nit stitches A in Wales 1. As a result of this arrangement, the elongated loops S of each yarn a are doubled with the plain knit stitches A of the next succeeding yarn a in the fabric. Thus, stitches B actually anchor the double stitiches SA throughout the fabric.

Similarly, the plain knit stitches B and floats H of each yarn b are staggered Wale-wise with respect to the stitches B and floats H of the next successive or adjacent yarn b in the fabric Preferably the floats H are bound into the fabric by the elongated loops S.

If it is considered that each course-wise extending yarn of the fabric of FIG. 1 comprises a separate fabric course, then it will be seen that the pattern repeat of the fabric is two needle wales in width and four courses in length.

In the preferred construction of the fabric, yarn a is of a longer length per fabric course than yarn b, but of smaller denier. For example, a highly run-resistant fabric of the character shown in FIG. 1, having the appearance of plain knit fabric, is produced when yarn a has, per course, twice or more than twice the length of yarn b per course, and has one-half the denier of yarn b.

The fabric of FIG. 1, having a longer length of yarn a per course than yarn b, is highly resistant to runs even when subjected to substantial width-wise or length-wise stress. In such situation, runs are deterred when a yarn is broken, for all practical purposes in the normal use of the fabric, because withdrawal of the double stitches SA, from plain stitches B is precluded.

FIGS. 2-4 illustrate the best mode presently contemplated for carrying out this invention. While, for purposes of illustration, the herein described method and apparatus illustrate the invention as practiced on a two-feed circular knitting machine, it is to be understood that the invention may be practiced on circular knitting machines having multiples of two yarn feeds, i.e., 4, 6, 8, etc. yarn feeding stations.

The needles of the machine preferably are divided into two groups, designated N and N which alternate in a l x 1 relationship around the needle circle. Needles N are formed with the usual needle butts N, and may also have auxiliary butts N (FIG. 3). Needles N are formed with the usual butts N, and, in addition, may also be formed with auxiliary butts N Referring now to FIG. 2, it will be seen that the needles, during their stitch formation action, move counterclockwise in the rotative direction R. As the needles approach the first or main yarn feed of the machine, to take yarn a, they are divided alternatively by conventional needle selection means into the two needle groups N and N with needles N raised to clear level, i.e., latch clearing level, and needles N disposed at tuck level E (FIG. 2x). More particularly, the needles N and N are selected by needle jacks T under the influence of reader cams O or O in the usual manner.

As needles N approach the first yarn feed, at clear level, they have stitches B of the yarn b on their shanks or stems below their latches Z. Needles N at tuck level E, have elongated yarn loops S of yarn a on their open and downwardly extending latches Z and have floats H, of the next succeeding yarn b to the said yarn a, and stitches B, of the next preceding yarn b to the said yarn a (FIG. 1), onthe needle shanks below their latches Z (FIG. 2x). The stitches B on needles N and the floats H on needles N are formed from the same course-Wise extending yarn b in the fabric.

While the needles approach the first yarn feed, the sinkers P are advanced into the needle circle by the cam surfaces P and P of sinker cam P (FIG. 4). As a result, at the first yarn feed, yarn a is drawn over the sinker nebs P by needles N to form stitches A (FIGS. 2a, 3), while yarn a is laid over the latches Z of needles N and over the sinker nebs P to form elongated yarn loops S.

The first yarn feed is provided with two vertically spaced run-down cams C and C (FIG. 2). Cams C and C are spaced from each other to provide therebetween a needle butt track corresponding in width to the width of the needle butts N and N The conventional reverse stitch cam C and top center cam C are retracted from the needle circle and rendered inoperative.

Yarn a is delivered into the hooks of the needles N and N and then needles N are drawn down by run-down stitch cam C to form stitches A and cast off the floats H and the stitches B (FIG. 2a). Since elongated loops S are still in the hooks of needles N they are doubled with the newly formed stitches A to form double loops SA.

Needles N meanwhile, with the newly formed yarn loops S on their open latches, are drawn down by cam C to a depth intermediate of tuck level E and yarn cast off level (FIG. 2a). As a result, stitches B remain on the shanks of the needles N below their latches Z, while the newly formed loops S remain on and above the needle latches. The retention of loops S on the needle latches and separate from loops B on the shanks of needles N is aided by the retention of the sinker nebs P within the needle circle (FIG. 4).

After stitches A have been drawn by needles N the sinkers P are further inserted into the needle circle by cam surface P of sinker cam P (FIG. 4). Sinker cam surfaces P and P serve as knockover cams, and aid in casting floats H and stitches B off of needles N during the formation of the new stitches A from yarn a. Sinker cam surfaces P and P advance the sinkers P sufliciently far into the needle circle to position the yarn drawing ledges P behind the sinker nebs P below the hooks of the needles N After passing stitch cams C and C all needles N and N are raised to tuck level E. Thereupon, all needles are raised to low clear level by cam C As a result, the double thread stitches SA are cleared from the latches onto the stems of needles N However, because the sinker nebs P still penetrate the needle circle, the thread loops S are retained on the latches Z of needles N Preferably, at this time, the sinkers P are retracted slightly by sinker cam P (FIGS. 2b, 4), so that the highest point of the sinker nebs P is positioned below the loops S on needles N and above stitches B on needles N and double stitches SA on needles N As an alternative, cam C may be omitted and the sinkers not retracted, but allowed to remain as positioned by cam surface Ps. In such case, needles N only are raised, independently of needles N by their jacks T under the influence of reader cams O or 0 (see broken lines in FIG. 2), to latch clearing level. Consequently, the double stitches SA slip off the latches Z onto the shanks of the needles N As the needles continue their movement in direction R, they are drawn down by cam C to or slightly below tuck level E. Thereafter, needles N are raised to low clear level, by needle jacks T under the influence of reader cam O or 0 However, the thread loops S are retained onthe latches of needles N by the sinker nebs P, which remain within the needle circle (FIG. 4). Needles N meanwhile, remain at or slightly below tuck level E. In these respective positions, the needles N and N advance toward the cams C and C while taking yarn b at the second yarn feed.

Needles N take yarn b in their hooks and are drawn down by the run-down stitch cam C to form new stitches B and cast off double stitches SA. Cam C is spaced sufiiciently far in advance of cam C to draw needles N down to yarn cast off level before needles N reach cam C 4 As a result, needles N cause the yarn b to be laid below the latches Z against the shanks of the needles N (FIG. 20) to form floats H.

Needles N retain the yarn floats H under tension against the shanks of needles N until the latter needles have descended sufliciently to enclose the yarn floats H between their latches and shanks. To aid needles N in this function, cam C preferably is formed with a flat bottom of a length suflicient to retain at least three needles N at any moment, at cast off level.

More particularly, cam C retains needles N at cast ofl. level until after needles N have passed over cam C advanced to cam C and are caused to descend to tuck level E by the latter cam. This downward movement of needles N ensures the proper positioning of the floats H of yarn b between the latches and shanks 0f the needles N After cam C has lowered needles N to tuck level E, needles N are raised to tuck level E. At this stage of the process, needles N have yarn loops S on their latches and floats H and stitches B below their latches on their shanks, while needles N have new stitches B on their latches. The floats H on the shanks of needles N and the new stitches B on the latches of needles N are formed from the same course-wise extending yarn b, whereas the stitches B on the shanks of needles N are formed from the immediately preceding course-wise extending yarn b (see FIG. 1).

As the needles N take and draw yarn b, the sinkers P are positioned in respect of the needle circle so that stitches B are drawn by needles N over the yarn sinking ledges P behind the nebs P (FIGS. 20, 4). To accomplish this, sinkers P either remain in the position to which they had been advanced by cam surfaces P and P or, if they had been retracted slightly by cam P they are readvanced under the influence of sinker spring N.

Sinker cam P (FIG. 4) serves as the knockover cam for the second yarn feed. It advances the sinkers P further into the needle circle to aid in casting olf double stitches SA from needles N Because stitches B of yarn b are drawn over sinking ledges P of sinkers P, and stitches A of yarn a are drawn over the sinker nebs P yarn or will have a longer length per course of the fabric than yarn b. Of course, even if the two yarns were drawn over yarn sinking ledges at the same level, yarn a inherently will have a longer yarn length per course than yarn b, since the latter contains the floats H, whereas the former contains the inherently longer loops S.

Specially designed sinkers P are employed to carry out the method of the invention. The sinkers are formed with a rearwardly extending edge passing first downwardly from the top of the neb P to the sinking ledge P and thence upwardly to a point spaced from the neb, as best shown in FIG. 2a. Sinking ledge P is the lowest portion of this rearwardly extending edge, and is disposed somewhat lower than sinker throat P. The vertical distance between the uppermost point of sinker neb P and the yarn sinking ledge P may be selectively designed to control the relative lengths per course of the yarns a and b. Preferably, the distance from the sinker throat P to the sinking ledge P should not exceed the width of the hooks of the needles N N In order to facilitate the usual broken needle detector V (FIG. 2d), all needles N and N are drawn below tuck level E a small distance by cam C Preferably, the needles are drawn down to position their hooks proximate the sinker nebs P, so that the floats H and stitches B on needles N close the latches Z, but do not cast off. At this time, the sinkers P may be retracted by sinker cam P to position all yarn loops on the needles below the nebs P (see broken lines in FIG. 2d). Thereafter, all needles N and N are again raised to tuck level E while proceeding in the rotative direction R to the next yarn feed which, in the embodiment shown, is the main or first yarn feed of the machine.

Before the needles again take yarn, they are selected to interchange their previously described action. More particularly, needles N now are raised to clear level (FIG. 2x) to transfer their stitches B onto the needle shanks, while the needles N remain at tuck level E. Needles N now have elongated loops S on their open latches and floats H and stitches B on their shanks below their latches. Meanwhile, the sinkers P have been retracted from the needle circle, by either of sinker cams P or P", and thereafter are re-advanced into the needle circle by cam surfaces P and P to permit yarn a to be drawn over the sinker nebs, as previously described.

It is advantageous to reinsert the sinker nebs P into the needle circle gradually, first by cam surface P and thereafter, to a further extent, by cam surface P This arrangement will ensure that the tips of the sinker nebs will not re-engage the loops S on the needles, but will pass above those loops, as yarn a is drawn into the stitches A by the needles N or N Needles N now at tuck level, take yarn a, form double stitches SA and cast off floats H and stitches B, while needles N take yarn a to form new elongated loops S on their latches. After needles N and N again pass the two yarn feeds, they are selected to reverse again their yarn formation actions, i.e. to revert to the actions originally described. Thus, after passing each second yarn feed of the machines, the needles, by conventional selecting means, are reversed in their functions to produce double stitches SA, stitches B and floats H in staggered relation throughout the fabric, in the manner shown in FIG. 1.

Because the stitches B are drawn behind the sinker nebs P the floats H underlie the elongated loops S and are bound thereby into the fabric (FIG. 1). If desired, the yarn b may be drawn to stitches B on the usual yarn sinking ledge in front of the sinker throats P with appropriate rearrangement of the needle and sinker motions. In such case, floats H would overlie, rather than underlie, loops S in the fabric.

Additionally, if desired, alternate sinkers only may be inserted into the needle circle at the first yarn feed, by appropriate sinker selection means, to draw yarn a over the nebs of alternate sinkers only.

It is contemplated that, instead of the needle selection means discussed above for selecting needles N and N modified means may be employed utilizing the auxiliary needle butts N and N In such case, the needles N and N would be moved independently of each other by means of additional needle cams (not shown) arranged at different vertical levels of the machine, and acting upon the auxiliary needle butts N and N.

If desired, in making ladies hosiery, the heel and toe portions may be made by reciprocatory knitting. In such case, during reciprocatory knitting, cams C and C at the first yarn feed would be reinserted to operative position to act upon the needles. No needle butts would enter the track formed between cams C and C during the forward stroke of the needle cylinder, but all needles N and N would be drawn down to cast off level by cam C During the reverse stroke of the needle cylinder, the ieedles would be drawn down by cams C and C in the sual manner. The reciprocatory knit portions of the fabric would, of course, be a plain knit.

FIG. 5 shows a preferred needle N for carrying out this invention. Needle N is formed with a reduced portion at the front thereof, below latch Z and with a second reduced portion 20, formed at the back thereof, below the latch hinge 30. Reduced portion 10 facilitates the formation of the floats H from yarn b, and reduces the strain on the yarn. Reduced portion serves to relieve tension on the loops B after their formation from yarn b.

It is to be understood that the invention described and shown herein is susceptible of various changes and modifications, which may be made without departing from the general principles or spirit of the inventive concept. Accordingly, it is intended to claim the invention broadly, as well as specifically, in the appended claims.

Having thus described our invention, we claim:

1. A multi-feed circular knitting machine having a complement of needles with butts and two successive yarn feeding stations, said machine including (a) a run-down stitch cam at each of said yarn feeding stations for lowering needles to yarn cast off level and (b) a second cam at each of said stations for lowering needles to a level above yarn cast off level,

(c) each second cam being spaced from its adjacent stitch cam a distance not less than the width of a needle butt track corresponding to the Width of the needle butts.

2. The invention of claim 1 further including needle selection means in advance of each yarn feeding station to select a group of needles to be lowered by the rundown stich cam and to select a good group of needles to be lowered by the second cam.

3. The invention of claim 1 further including needle selection means in advance of each yarn feeding station to select needles to be lowered by the run down stitch cams.

4. The invention of claim 1 further including needle selection means in advance of each yarn feeding station to select needles to be lowered by the said second cams.

5. In a multi-feed circular knitting machine having a plurality of latch needles for knitting run-resistant fabric (a) a first yarn feeding station including means for feeding yarn to the needles,

(b) a pair of spaced cams at said first station for lowering the needles, said cams being spaced from each other a distance sufiicient to provide a needle butt track therebetween,

(c) one of said cams being adapted to lower nonselected needles to yarn cast off level and the other of said cams being adapted to lower selected needles to a level above yarn cast off level,

(d) a second yarn feeding station spaced from the first yarn feed and including means for feeding yarn to the needles,

(e) means disposed between the said stations for raising the non-selected needles to clear yarn from their latches,

(f) means in advance of the second station for dis posing the cleared non-selected needles at tuck level and for disposing the selected needles at latch clearing level,

(g) a pair of spaced cams at the second station for lowering the needles,

(h) one of said latter cams being adapted to lower the non-selected needles to yarn cast off level and the other of said latter cams being adapted to lower the selected needles to tuck level.

6. The invention of claim 5 wherein the machine includes a plurality of sinkers each having a neb, and further including a sinker cam for advancing the sinkers into the needle circle at the first station a distance sufficient to permit the needles to draw yarn over the sinker nebs.

7. The invention of claim 6 further including a sinker cam for advancing the sinkers into the needle circle at the second station a distance suflicient to permit the nonselected needles to draw yarn over yarn sinking ledges disposed behind the sinker nebs.

8. The invention of claim 5 further including a broken needle detector and a cam to lower all needles to a depth sufficient to cause yarn on the needle stems to close the needle latches Without casting ofl 9. The invention of claim 7 further including a sinker cam for withdrawing the sinkers from the needle circle after the needles receive yarn at the second yarn feeding station.

10. The invention of claim 5 wherein each needle has a reduced portion at the back thereof below the hinge of its latch and a second reduced portion at the front thereof, disposed below the latch.

11. The invention of claim 6 wherein each sinker has a throat and a yarn sinking ledge disposed behind the neb, said ledge being disposed lower than the throat.

12. In a circular knitting machine having a plurality of latch needles and sinkers with nebs and a yarn feed, means for forming spaced elongated yarn loops and intervening knitted stitches course-wise of a knitted fabric comprising (a) needle selection means for disposing selected needles at latch clearing level and the remaining needles at tuck level.

(b) a first cam disposed at the yarn feed for lowering the non-selected needles to yarn cast off level,

() a second cam disposed at the yarn feed for lowering the selected needles to a level above yarn cast off level, whereby said selected needles do not cast off (d) said cams being spaced from each other a distance suflicient to provide a needle butt track therebetween, and

(e) a sinker cam adapted to advance the sinkers into the needle circle at the yarn feed.

13. The invention of claim 12 further including (a) means for feeding yarn to the needles,

(b) means for raising the non-selected needles, after feeding yarn thereto, to clear yarn from their latches and (c) means for retaining yarn on the latches of the selected needles.

14. The invention of claim 13 wherein the means for retaining yarn on the latches of the selected needles comprises a sinker cam for positioning the sinker nebs within the circle of needles below the yarn on the latches of the selected needles.

15. Means for forming yarn floats in spaced wales of a knitted fabric on a circular knitting machine having at least one yarn feed and a plurality of latch needles comprising (a) means for raising selected needles to latch clearing level,

(b) a first cam for lowering the non-selected needles to yarn cast off level,

(0) a second cam spaced from the first cam for lowering the selected needles to tuck level and (d) means for feeding yarn to the hooks of the selected needles,

(e) said second cam being spaced from the first cam a distance sufficient to cause the non-selected needles to position the yarn against the shanks of the selected needles below the latches of said selected needles to form thereby the yarn floats.

16. A method of knitting run-resistant fabric on a circular knitting machine having a plurality of latch needles and sinkers having nebs comprising the steps (a) dividing the needles into a first group disposed at latch clearing level and a second group disposed at tuck level,

(b) delivering yarn to the hooks of the needles,

(c) lowering the second group of needles to yarn cast off level,

(d) lowering the first group of needles to a level above yarn cast off level, whereby said needles do not cast 01f yarn,

(e) raising the second group of needles to clear yarn from their latches,

(f) dividing the needles into the same two groups aforesaid and disposing the first group at latch clearing level and disposing the second group at tuck level,

(g) delivering yarn to the hooks of the second group of needles,

(h) delivering yarn to the stems of the first group of needles, below the latches thereof, and then (i) disposing all said needles at tuck level.

17. The method of claim 16 wherein the sequence of steps is repeated, but with the manipulations of the two groups of needles reversed.

18. The method of claim 16 wherein the needles of the first group each form elongated yarn loops which are retained on the needle latches and the needles of the second group each form two successive knitted stitches.

19. The method of claim 18 wherein yarn floats are formed on the stems of the needles of the first group while said needles retain the elongated yarn loops on their latches.

20. The method of claim 16 further including the step of disposing the sinker nebs within the needle circle to maintain the elongated yarn loops on the latches of the needles of the first group.

21. The method of claim 19 further including the step of positioning the sinker nebs within the circle of needles to maintain the elongated yarn loops on the latches of the needles of the first group.

22. A method of forming yarn floats in spaced wales of aknitted fabric on a circular knitting machine having a plurality of latch needles and at least one yarn feed comprising the steps (a) dividing the needles into two groups and disposing one group at latch clearing level and disposing the other group at tuck level,

(b) delivering yarn to the hooks of the needles dis- .posed at tuck level,

(0) delivering yarn to the stems of the needles disposed at latch clearing level, below the latches thereof, to form yarn floats,

(d) lowering the needles disposed at tuck level to yarn cast off level to cast oif of said needles yarn loops disposed below the latches thereof and then (e) disposing all said needles at tuck level.

References Cited UNITED STATES PATENTS 1,821,848 9/1931 Pons 66108 2,044,324 6/ 1936 Page 66121 2,249,790 7/1941 Page 66121 2,525,704 10/1950 Miller 6642 2,536,478 1/1951 Vitoux 66121 XR 2,073,703 3/ 1937 Micks 66108 3,080,740 3/ 1963 Nebel 66108 3,148,518 9/1964 Peel et a1. 6642 3,260,072 7/ 1966 Millar et a1 66108 XR FOREIGN PATENTS 594,008 5/1959 Italy.

RONALD FELDBAUM, Assistant Examiner.

U.S. Cl. X.R.

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