US2965330A - Apparatus for controlling twisted yarn - Google Patents

Description

Dec. 20, 1960 S- J. HOEKSTRA APPARATUS FOR CONTROLLING TWISTED YARN Filed Dec. 17. 1956 $705M JACOB FIG. I

FIG. 2

INVENTOR.

HOEKSTRA United States Patent APPARATUS FOR CONTROLLING TWISTED YARN Sjoerd Jacob Hoelrstra, Emmen, Netherlands, assignor to American Enka Corporation, Enka, N.C., a corporation of Delaware Filed Dec. 17, 1956, Ser. No. 628,901

Claims priority, application Netherlands Jan. 5, 1956 1 Claim. (Cl. 242-128) This invention relates to an apparatus for controlling twisted yarn. More particularly, this invention relates to an apparatus for controlling highly twisted yarn during delivery from a yarn package to a knitting machine.

In the production of certain fabrics having stretchable characteristics, highly twisted yarns are required. Fabrics having unusually high stretching properties may be produced from filaments of certain fiber-forming synthetic thermoplastic polymers which are heat-set in a twisted condition.

A method of producing a heat-set twisted yarn generally comprises twisting a thermoplastic yarn, multi-filament or monofilament, to provide either an S-twist or Z-twist, heating the twisted yarn to a temperature suflicient to set the yarn, and cooling the yarn while in the twisted condition. This is known in the art as a heat-setting operation. Although this twisted yarn does not lose its twisted shape when in a relaxed state, there is a tendency for the yarn to snarl into kinks.

Most any highly twisted yarn presents problems to the knitter. One of the greatest problems is the tendency of the yarn to kink between the yarn tensioning devices and the yarn package when the yarn is not continuously being fed into the knitting machine. In a knitting operation, when delivery of a twisted yarn over an end of a package to the machine is discontinued, the yarn tends to recoil and to twist itself into kinks near the yarn package. When knitting is resumed, the kinks may not be straightened out, with knots resulting. Accordingly, an inferior fabric will be knitted.

One of the most important commercial utilizations of heat-set twisted monofilament yarn is found in the production of ladies full-fashion stretchable hose. Nylon is the usual material used in the manufacture of this type of hosiery. Before being heat-set, the nylon yarn is twisted to 50 or more turns per inch, preferably about 35 turns per inch. The temperature required for the heatset step is dependent on the type of nylon used. For example, nylon yarn produced from the polycondensation of hexamethylene diamine and adipic acid must be heatset at a higher temperature as compared to polycaprolactam nylon yarn.

In the manufacture of certain stretchable fabrics, two strands of Z-twisted yarn, for example in making womens hose, are knitted alternating successively with two strands of S-twisted yarn. Therefore, while the yarn of one type of twist is being knitted, the yarn of the other type of twist is not moving. Hence, each time the movement of the yarn stops, the kinking problem arises.

Means have been suggested for overcoming the kinking problem. For example, caps of various sizes and shapes for yarn packages have been used. These caps or discs are arranged coaxially with the yarn package. Here, the twisted threads are directed upwardly or downwardly, as the case may be, from the package and contact the periphery of the disc during the draw-ofi of the yarn. These discs which have not been entirely satisfactory are constructed from plastic material or the like and have a smooth or slotted outer edge. When these known discs are employed in drawing 01f a twisted yarn, the kinking problem is not entirely eliminated.

Although the known types of discs may overcome the kinking problem to a limited extent when the diameter of the discs is about twice the size of the diameter of the empty spool, pirn or cone, they are notably less effective when the diameter of the yarn package is greater than three quarters of the diameter of the disc.

An object of the present invention is to provide a novel apparatus for directing a highly twisted yarn in a discontinuous manner to a knitting machine without the yarn forming knots or kinks.

Another object of the present invention is to provide a unilaterally operating yarn tension device for the prevention of kinking during the idle portion of intermittent unwinding of highly twisted yarn over an end of a yarn holder.

These and other objects will become apparent from the following more complete description of the instant invention.

According to the present invention, a yarn holder disc is provided which overcomes the aforesaid kinking problem. The disc is mounted at one end of a yarn holder containing a package of highly twisted yarn. A strip of fur is attached around the periphery of the disc, the hairs of said for projecting into the path of the yarn and extending outwardly from said disc in the direction of rotation of the yarn around said disc during unwinding. Upon withdrawal of the yarn around the disc in the direction which the hairs extend, the yarn will glide over the fur;

but upon discontinuation of withdrawal, the yarn, having a tendency to reverse its direction, becomes tensioned by the hairs and is thus prevented from kinking.

Referring to the accompanying drawing which illustrates one embodiment of the invention;

Figure 1 is a perspective view of a yarn holder disc mounted at an end of and coaxially arranged with a spool on which twisted yarn is wound; and

Figure 2 shows the disc, spool and yarn in a longitudinal sectional view.

A main feature of the invention consists in the use of the disc indicated generally by 11 which comprises a flat sheet-shaped ring 12 provided with a raised edge or axially extending flange 13 near its outer periphery. Reference number 14 denotes an outer radially protruding rim formed beyond the raised edge 13. A strip of fur 15 is attached to the outer side of the edge 13. Rim 14 is sufiiciently narrow that the hairs of the strip of fur 15 protrude only slightly beyond the edge of the rim.

The inner portion of the ring 12 extending inwardly forms a flange 16 which is provided with a plurality of indentations 17. This arrangement provides a ready means for a force-fit attachment Within the body portion 18 of a yarn holder on which yarn 19 is wound.

A thread guide 21 is positioned above the disc 11 so that the thread 20 maintains contact with the disc during withdrawal of the thread from the yarn package, for example, by driven roller 22, to a point of use, not shown. Withdrawing endwise from the package of course results in rotating or revolving the yarn about or relative to the package holder.

In Figure 1 the thread 20 has an S-twist and is drawn off in a counterclockwise direction. In order to prevent the formation of kinks in the thread 20, the hairs of the fur piece must also be directed counterclockwise. Hence, the thread 20 when drawn off will glide over the hairs, or with the grain.

When the movement of the thread 20 is halted, the thread will tend to recoil in the direction against the grain of fur because of the high twist contained therein and will immediately be tensioned between the hairs of the fur and thereby be prevented from kinking.

On the other hand, a Z-twisted yarn is run off in a clockwise direction; and in this case a strip of fur will be used in which the hairsof the fur are laid clockwise. The position of the hairs depends upon the direction in which the yarn is run off which in turn is dependent upon whether S-twisted yarn or Z-twisted yarn is withdrawn from the yarn package. The grain of the hair must run in the direction in which the yarn is removed.

The radially protruding rim 14 prevents the yarn from being pressed too firmly against the fur 15. Preferably, the edge of rim 14 should not protrude beyond the outer diameter of the strip of fur. Also, rims may be arranged at the top and bottom of the strip of fur, if desired, provided neither of said rims has a diameter larger than that of the strip of fur.

An important feature of the present invention is that the diameter of the disc 11 need not substantially exceed the diameter of a fully wound yarn package. This is an advantage since conventional package sizes may be used without the need of larger humidification chambers on conventional knitting machines.

Furthermore, the diameter of disc 11 with regard to the diameter of the yarn holder is less critical as compared with known discs.

The disc may be an integral part of the body portion of a yarn holder, such as a spool, pirn or bobbin on which the yarn is wound or it may be a force-fit arrangement as shown in Figure 2.

The fur as used in the present invention may be animal fur. Preferably the fur used in accordance with the present invention should be short-haired or shorn. Animal fur of various kinds, such as rabbit, squirrel, fox, wolf, and the like, are satisfactory. Of course, fur made from synthetic fibers or a blend of natural and synthetic fibers having physical characteristics of animal fur is also satisfactory.

The fur may be attached to the disc in any satisfactory way, such as by means of glue or other adhesive.

It will be understood, however, that the yarn holder cap may be modified without departing from the present invention. Thus, the cap may be manufactured from wood, metal or synthetic material.

What is claimed is:

A unilateral yarn tensioning device operative to prevent kinking during the idle portion only of intermittent unwinding comprising an elongated yarn holder containing a package of highly twisted yarn, a disc mounted at one end of said elongated yarn holder in coaxial relationship therewith and having an overall diameter which only slightly exceeds the initial diameter of the yarn package on said yarn holder, said disc including a flat ring extending radially of said yarn holder, a rim protruding radially outwardly from the periphery of said ring, a raised flange extending axially from said ring near the periphery thereof, and a strip of fur attached around the outer peripheral surface of said flange, said fur having hairs secured at one end to said flange with the free ends thereof projecting outwardly of said flange slightly beyond the outer surface of said rim and extending substantially circumferentially about said ring, substantially all of said hairs extending in ,I the same circumferential direction, and means for withdrawing said highly twisted yarn over the end of said References Cited in the file of this patent UNITED STATES PATENT S 1,206,870 Lipps Dec. 5, 1916 1,209,179 Lipps Dec. 19, 1916 1,289,987 West Dec. 31, 1918 1,851,243 Egli Mar. 29, 1932 2,771,756 Burleson et al. Nov. 27, 1956

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