GB2191788A - Yarn creel - Google Patents

Abstract

A creel for elastomeric yarns 2 comprises means, such as support rollers 6, for rotatably mounting individual yarn packages 4, and a plurality of tensioning devices 5 operative for tensioning of the yarns 2 individually or in groups as the yarns are drawn from the creel by a yarn consuming machine. The tensioning devices 5 conveniently comprise tensioning wheels 14 around each of which a yarn 2 passes, and which are individually or in groups rotatably coupled with braking means in the form of a band brake comprising a brake wheel 15 around which an adjustably tensioned friction cord 17 passes. Each wheel 14 has a yarn-guiding peripheral groove of sinuous shape. The creel may feed yarns to a weaving or knitting machine. <IMAGE>

Description

SPECIFICATION Yarn creel The invention relates to a yarn creel from which yarns are dispensed for use by a weaving, knitting or other yarn consuming machine. It is particularly, but not exclusively, concerned with the dispensing of elastomericyarn for use in the production of narrow width fabrics.

Narrow width elastic fabrics are normally woven or knitted from a plurality ofelastomericyarnsfed under tension from a common warp and a plurality of inelastic yarns fed from a second warp. Awarp is a cylinder or beam on to which a plurality of parallel yarns are spooled in a warping operation, and for el astomericyarns this is usually done by a supplierto the manufacturer ofthe fabric.

Conventionally, warping of elastomeric yarns is performed by winding a plurality of such yarns in parallel on to a peripherally driven beam, the yarns being fed from packages which are also peripherally driven by respective counter-rotating rollers on which they rest. Ideally this achieves a constant rate of feed, however in practise because the yarn may itself not have been wound on to the yarn package with the correcttension bytheyarn manufacturer, and also because under certain circumstances a package can bounce on the counter-rotating rollers, it has been found that the yarn feed rate on to the beam can vary unacceptably.

During a weaving or knitting operation the elastomericyarns are drawn by the consuming machine from the warp at a substantially constant rate bythe incremental feed demand of the machine. Tension in the yarns is maintained by the application of a braking force on the warp, usually by the action of a band brake on the beam. If the tensions in the individual yarns are not substantially the same, a distorted fabric can be produced. If the tensions in the yarnstowards one side of fabric are abnormaily greater than in those towards the other side, the fabric will be fed from the consuming machine with an inherent directional bias.If the abnormally tensioned fibres are distributed throughoutthe fabric then unsightly bellying of the surface ofthe fabric can result.

Using a braking action on the warp to maintain tension in the yarns as they are drawn therefrom does not permit control individually of the tension in each yarn. It is therefore important that yarns are spooled on to and stored in the warp undersubstan tiallythesametension.

It is an object of the invention to provide a yarn creel from which a plurality of elastomeric yarns may be drawn directly by a yarn consuming machine, such as a weaving or knitting machine, wherein the yarns are each, or in groups, fed therefrom at a pred etermined tension.

According to the invention a creel for elastomeric yarns comprises means for rotatably mounting individual yarn packages, a plurality oftensioning devices operative for the tensioning of yarns individually or in groups as said yarns are drawn from the creel by a yarn consuming machine which may conveniently comprise a weaving or knitting machine.

Preferably the tensioning devices comprise nonslip tensioning wheels around each of which a yarn passes, and which individually or in groups are rotatably coupled with braking means.

The braking means, for each individual tensioning wheel or group of wheels, may be a band brake which comprises a brake wheel around which is passed a friction band or cord. The friction cord is preferably anchored at one end and at the other end attached to one end of a helical spring, with the other end of the spring attached to an adjustable anchor point.

The invention will now be further described with reference to the accompanying drawings which illustrate, byway of example, a preferred embodiment of the invention. In the drawings: Figure lisa diagrammatic side view of a creel embodying the invention; Figure2 is a diagrammatic rearview; Figure3isadiagrammatictopview; and Figure 4is a partial view illustrating the path of a yarn through the creel illustrated in Figures 1 to 3.

An elastomeric yarn tensioning creel 1, illustrated in Figures 1 to 3,from which a pluralityofelastomericyarns 2 are dispensed comprises a supportframe 3, support means for the yarn packages 4, guide meansfortheyarns2anda pluralityofyarntensioning devices 5.

The support means for the yarn packages 4 comprises an array of rollers 6 on each of which can be mounted an individual yarn package 4. Each roller6 has an axle 7 rotatably supported by a pair of bearing blocks 8 which are rigidly attached to the support frame 3. Alternatively the yarn packages 4 may be individually supported between counter-rotating rollers which are mounted on the frame 3, one or other ofwhich may act as a friction brake to facilitate the take-up of the yarn 2 by the associated tensioning device 5.

Said guide meansfortheyarns 2 are provided to align and directthe plurality ofyarns to andfromthe respective tensioning devices 5. The guide means comprise first horizontal guide bars 9, each of which is rigidly mounted to a pair ofvertical support members 10 oftheframe 3, a horizontal guide roller 11 rotatably mounted to the frame 3, a vertical guide bar 12 mounted to the frame 3 below the tensioning devices 5 and a second horizontal porcelain guide bar 13.

The yarn tensioning devices comprise tensioning wheels 14which are individuallyorin groups rotatably engaged with a brake wheel or pulley 15. Each tensioning wheel 14 has a peripheral groove of generally sinuous shape in developed view, within which the yarn is looped around the wheel so asto befrictionally gripped thereby. The tensioning wheels 14 and the associated brake pulleys 15 may be conveniently mounted on one or more common spindles 16.

Inthetensioning device 5 illustrated in detail on Figure 4 a single tensioning wheel 14 is shown rotatably coupled with a brake pulley 15, the wheel 14and the pulley 15 being rotatably mounted on one ofthe spindles 16. In operation a yarn 2 is drawn at a substantially constant rate from a yarn package3, through the associated guideway of a first guide bar 9, around the roller 11 at which slip can occur, through the respective guideway in the guidebar 12, around the tensioning wheel 14 at which effectively no circumferential slip occurs and finally through the respective guideway of the second guidebar 13 to a yarn consuming machine (not shown). The yarn 2 is drawn from the creel 1 bythe yarn consuming machine which may comprise a weaving or a knitting machine.The yarn 2 is tensioned by the application of a braking force to the pulley 15 as the yarn 2 is drawn from the creel 1, hence the tension in the individual orthe groups of yarn 2 can be controlled by the braking force which is applied to the associated pulley 15.

The braking force on the tensioning wheel 14 illustrated in Figure 4 is provided by a cord brakewhich comprises the corresponding brake pulley 15, a plastics cord 17, an anchor bar 18, a helical spring 19, a threaded rod 20, an anchor bracket 21 and a thumbnut 22. The cord 17, which is of nylon thread, has a loop formed at each end, one ofwhich is retained by the anchor bar 18. The cord 17 then passes around the brake pulley 15, which is conveniently made of a plastics material such as "POLYPENCO" (Registered Trademark), and the other end loop is attached to an upper end of the spring 19. The lower end of the spring 19 is attached to an upper end of the threaded rod 20, and rod 20 passes through a clearance hole in the anchor bracket 21.In operation the thumb-nut 22 is screwed to a suitable position on the rod 20 against the underside ofthe bracket 21 to tension spring 19 and cord 17, thereby bringing the cord 17 intofrictional engagemeiitwfththe rotating brake wheel 15.

The tension in the cord 17 and therefore the resultant tension in a drawn yarn 2 can be varied by altering the relative position ofthethumb-nut 22 along the rod 20.

The anchor rod 18 is conveniently detachably mounted to the frame 3, for ease of attachment of cord 17 and may suitably be common to a plurality of cords 17 The anchor bracket 21 is conveniently rigidly attached to the supportframe 3 and may be common to a plurality ofthethreaded rods 20. In a second embodiment of the invention (not illustrated) the anchor bracket 21 is common to an individual or group oftensioning device or devices, and in this embodiment the bracket 21 is a movable part of a tension release mechanism, which can be constructed so that bythe operation of a simple lever or like meansthe bracket 21 will be moved to alterorre- lease the tension in the cord 17.The ability quicklyto release the brake from atensioning wheel 14 is particularly useful when replacing an exhausted yarn package 3 when it is necessary to thread the yarn end of a new package 3 through the tensioning device 5.

In use ofthe creel 1 it has been found that once the individual tensioning devices 5 are adjusted for a particularyarntype, re-adjustment is unnecessary when replacing an exhausted yarn package 3 with a new yarn package 3 of the same type.

A particular advantage of using the creel 1 to feed elastomericyarn to a consuming machine directly, is thatthetension of individual yarns can be controlled to enable a more consistent product two be obtained.

Furthermore, it is not necessary for a separate warping process to be performed because the yarns are feddirectlyfromtheyarn packages mounted onthe creel to the consuming machine, thereby enabling substantial savings in time and expense to be achieved. Also, the wastage associated with conventional warping ofelastomericyarns is avoided, wherein the warping is terminated as soon as any one oftheyarn packages is exhausted,therebywasting the residue of the remaining packages which is scrapped. Such wastage can amount two as much as 10% ofthe total yarn quantity.

The described construction of creel is of particularly compact design, thereby enabling the creel to be positioned in place of a bottom warp in a con ventional warp stand from which the yarn is supplied to the consuming machine. This is of particular advantage for installation in a fabric or garment manufacturing facility where space is of a premium.

Claims (10)

1. A creel for elastomeric yarns comprising means for rotatably mounting individual yarn packages, and a plurality oftensioning devices operative forthetensioning of yarns individually or in groups as said yarns are drawn from the creel by a yarn consuming machine.

2. A creel according to claim 1, wherein said tensioning devices comprise non-slip tensioning wheels around each of which a yarn passes, and which individually or in groups are rotatably coupled with braking means.

3. A creel according to claim 2, wherein each tensioning wheel has a peripheral groove within which the yarn is looped around the wheel so asto befrictionally engaged thereby.

4. A creel according to claim 3, wherein the peripheral groove of each tensioning wheel is of gener allysinuousshape in developed view.

5. A creel according to any one of claims 2 to 4, wherein said braking means, for each individual tensioning wheel or each group of such wheels, is a band brake which comprises a brake wheel around which passes a friction band or cord.

6. A creel according to claim 5, wherein thefriction band or cord of each band brake is anchored at one end and at the other end is attached to one end of a corresponding tension spring, the other end ofthat spring being attached to an adjustable anchor point.

7. Acreel according to claim 6, wherein said adjustable anchor point for each spring comprises a corresponding screw-threaded rod passing through an anchor bracket and retained therein by a thumb-nut threaded on the rod to provide individual manual adjustmentforthe braking devices.

8. A creel according to any one ofthe preceding claims, wherein said means for rotatably mounting the yarn packages comprise an array of rollers on each ofwhich can be mounted an individual yarn package.

8. A creel according to any one of claims 1 to 7, wherein said means for rotatably mounting the yarn packages comprise pairs of counter-rotating rollers between which the yarn packages can be individually supported, one or other ofthe rollers in use ac ting as a friction brake to facilitate the take-up ofthe yarn by the associated tension device.

9. A creel according to any one of the preceding claims,wherein guide means fortheyarns operative to align and direct the yarns to and from the respectivetensioning devices comprise horizontal guide bars below the yarn packages, followed by a vertical guide roller and vertical guide bar prior to the ten- sioning devices, and a horizontal guide bar defining yarn paths from the respective tensioning devices which extend over the yarn packages.

10. A creel for elastomeric yarns, substantially as herein particularly described with reference to the accompanying drawings.