US2532467A - Method for controlling yarn - Google Patents

Description

Dec. 5, 1950 E. ST. PIERRE METHOD FOR CONTROLLING YARN Filed Dec. 11, 1947 FIG. 3.

{NI 11705: GENEJZHERRE;

Patented Dec. 5, 1950 METHOD FOR CONTROLLING YARN Eugene Hemphill St. Pierre, Pawtucket, R. 1., assignor to Company, Central Falls, R. 1., a corporation of Massachusetts Application December 11, 1947, Serial No. 791,051

1 Claim. 1

This invention relates to a new and useful improvement in a method and device for controlling yarn in sources to the device by which it is used such as the needles of a knitting machine. It was devised for use with a circular, independent needle, hosiery knitting machine of the Banner type and the description will be based upon such a use. However, it is equally useful with other types of knitting machines and also with winding and other machines where the same problem is encountered. Certain yarns, particularly nylon, present special problems to the knitter. One is its tendency to untwist which apparently Originates in the general vicinity of the needles and extends back through the guides and tensions to the cone. When knitting is discontinued, the yarn unwinds a little from the cone creating slack. When this occurs, the yarn tends to twist upon itself to form outstanding pigtails which when knitting is resumed may straighten out or concentrate into knots. Broken yarn, defective fabric, broken needles and other difficulties result from such knotting. It is a characteristic which has caused great annoyance to users of certain yarns of which nylon is a conspicuous example and which, as far as is known, has been eliminated only by this invention.

One form of the invention is shown in the drawing of which:

Fig. 1 is a side elevation of such parts of a Banner knitting machine as are required for an understanding of the invention;

Fig. 2 is a rear elevation of the same parts;

Fig. 3 is a view illustrating the characteristic kinking of nylon which this invention prevents;

Fig. 4 shows a modified form of the invention; and

Fig. 5 shows a second modification.

As is well known, a knitting machine is provided with one or more sources of yarn, generally a cone, from which the yarn is run through suitable guides and tensions to the yarn levers and needles. As shown in Fig. 3, yarn I, assumed to be nylon, originates at the cone 2 and passes through eyelet 3 and, generally, additional eyelets, not shown, as well as one or more tensioning devices on its way to the yarn levers and needles.

While knitting is going on, the yarn runs continuously from the cone and is under some tension throughout its length so that no difiiculties with its travel are encountered. However, when knitting is stopped, a certain amount of slack appears adjacent the cone and may extend to the far side of one or more of the yarn guides whereits passage from its cone or from other upon the yarn is almost certain to twist upon itself into pigtails such as those shown at 4 and 5 in Fig. 3 which may or may not disappear when knitting is resumed. If they do not, knitting and mechanical troubles are certain to result.

The cause of this pigtailing of the yarn appears to be the untwisting of the yarn itself beginning adjacent the needle end of its travel which is reflected all the way back to the cone. When slack appears anywhere, pigtailing is likely to occur particularly if the length of yarn between adjacent guides or a guide and the cone is of any great length. At times it is practically impossible to knit nylon yarn for this reason unless the machine is kept in continuous operation.

This difiiculty has been completely solved by the simple but wholly effective method and device of this invention. The form shown in Fig. 1 consists essentially of a small spool or pulley 6 adapted to rotate with great freedom upon a pin 1 aflixed to a bracket 8 which is mounted upon a suitable part, such as the spider 9, of the machine more or less midway of the travel of the yarn between the cone and the needles. The yarn I after passing through on or more guides such as I0 and II is given a turn around pulley 6 and is then led to the needles through the usual guides and tensions. While knittin is going on, pulley 6 is caused to rotate by the pull upon the yarn produced by the needles. When knitting is stopped, the pulley stops. Any tendency to overrun may be prevented by a tension l 2 on the cone side of the pulley. This tension may serve as the or one of the regular tensions by which the knitting is regulated.

The pigtailing of the yarn heretofore described and which has been such a serious problem is wholly eliminated by pulley 6 used in this way. In efiect, the start of an artificial pigtail is produced by the loop of yarn around pulley 6 which is prevented from twisting upon itself to form a pigtail by the pulley. Also the bending of the yarn around the pulley stops its internal untwisting. Consequently, the yarn remaining between the pulley and the cone is effectively insulated from the causes which would normally produce pigtailing since these lie on the other side of pulley 6 and cannot proceed beyond that pulley. As a result, nylon and other difficult yarns can be used as easily as any of the many other yarns with which this troublesome characteristic is not encountered.

In Fig. 4 a modification is shown in which the yarn is given a partial turn instead of a full turn around a pulley I3 which corresponds to pulley 6. In this instance, it will be noted that the yarn reverses its direction so that the suggestion of a loop, such as that shown at 4 in Fig. 3 which is characteristic of pigtailing, is clearly suggested. To be effective, the yarn should be in contact with the pulley for a considerable length of its circumference. Otherwise, the effectiveness of the device is progressively impaired; In other words, the yarn about the pulley must have what is definitely recognizable as th beginning of a complete loop as distinguished from mere bandbut the exact minimum requirementldepends up-- on so many features that it can be determined only by trial.

In the form of the invention illustrated by Fig;

5, it will be noted that there are two pulleys M and I 5, each corresponding, to pulley-wand that the yarn is passed around one side of one pulley and around the other side of the other pulley. While the directions of the ends of the yarn are divergent, the suggestion .of a definite. loop, such as that shown in Fig. 4 is preserved; In thiszine stance, there are two such loops: In both the modified forms, as in the original form, thepulley or pulleys act as before withthe IBSlllUtl'lEilplg tailing tendency is eliminated.fromrthefiremaining yarn.

If greater resistance to the: travel. ofF-theyarn is not objectionable a. pin or othernon-rot'ating element may replace the pulley and, of course, the term pulley includes anyform of ifreely r;- tating element,

In the following claim the-words-l'oop and looped are'te be understood to include not-only the complete loop described-in co-nnectionwith the'form of the invention of'F-ig; 1-butalso partial loops or incomplete loops, such as those shown in Figs. 4 and 5 or, in other words; any loop -or bend in the yarn around an element which is suflicient to eliminate the pigtailing -tendency;de-

scribed. The degree of bend or loop in the yarn required for the purpose of this invention will vary with the kind, size and twist of the yarn and the mechanical arrangement of the machine and, consequently, cannot be more exactly specified.

I claim:

Amethod of controlling a length oftwisted nylon yarn running from asource of supply to a point where it is used progressively, such as to a'knitting needle, under conditions causing an alteration in thetwist of said yarn and a consequent tendency to pigtail if slack occurs adjacent said source of supply, which includes the steps of drawing saidyarn from the source of supply under no tension other than that resulting from the withdrawing of. said yarn to a tensioning device and thereafter forming a loop in said yarn and maintaining said loop in a single plane to prohibit transmission of alterations in yarn twist and eonsequentitendenoy to pigtailin the length of yarn between said source offsupply'an-dv said tensioning device.

EUGENE ST. PIERRE...

REFERENCES CITED The following references are of recordin the file of this patent:

UNITED STATES PATENTS Number Name Date- 1,977,686' Mayer Oct: 23, 1934 2,158,547 Lawson et a1 May 16,1939 2,432,518 Eshleman Dec: 16, .1947

FOREIGN PATENTS Number Country; Date 531,438 France Jan.v 12, 1922 568,259 Germany Jan. 17, 1933 686,055 Germany Jan.2, 1940

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