SE1650988A1 - Yarn feeding device with long yarn buffer - Google Patents

Abstract

Described are, among other things, methods and devices for feeding yarn to a textile machine (10). The yarn feeding device comprises a moveable yarn carrier (24) adapted to transport yarn in a first, forward direction and a loop former (18) adapted to draw yarn from a yarn storage (14). The device also has moveable loop keeping members (20) arranged at opposite lateral sides of an input section of the moveable yarn carrier, wherein the loop former is adapted to position yarn on the moving loop keeping members by moving the yarn from side to side. The moveable loop keeping members are adapted to hold the yarn positioned thereon and to release the yarn onto the moveable yarn carrier in a meandering pattern at an input area of the moveable yarn carrier and the yarn lying on the moveable carrier is adapted to leave the moveable yarn carrier at an output section of the moveable yarn carrier.

Description

Yam feeding device With long yam buffer TECHNICAL FIELDThe present disclosure relates to a yarn feeding arrangement. In particular the presentdisclosure relates to a yarn feeding arrangement suitable for a textile machine operated at high speed and potentially also With yams With relative high Weight per length unit.

BACKGROUNDYam pre-Winders are used to eliminate yam tension Variations to ensure high textile qualityand productivity of a textile machine, e. g. a shuttleless Weaving machine or a knitting machine.

A general development trend in Weaving is that the speed of the Weaving machine isconstantly being increased. At the same time the Weavers strive to Weave coarser yams andalso Weaker yams. A similar trend also exist for other textile machines. Coarser yams andhigher speeds lead to increased tension of the yarn. Using conventional yam pre-Winders,increased speeds as Well as coarser yams result in a bigger take off yam balloon in the yarnpre-Winder, Which needs to be reduced using a high braking force but thereby unfortunately leading to an undesirably high output yarn tension.

For example, When Weaving a carpet, coarse Jute is often used as yam. The balloon brakingelement in a conventional yam pre-Winder is typically either a brush ring or a flexibletruncated-cone formed brake element. With the machine speeds of today a brush ring isoften Wom out in as little as a day and a flexible truncated-cone brake element can be Wom out in a few months.

Another example is Weaving technical fabric With coarse synthetic yams; Where one faces the same problem as in a carpet Weaving machine.

Further, When using a shuttleless Weaving machine in the form of a rapier Weaving machine,the insertion means in the rapier Weaving machine consists of one or tWo rigid or flexiblerapiers that mechanically transfers the yarn from one end of the shed of the machine to theother. The most common system is tWo rapiers Which meet in the middle of the shed Wherethe yam tip is transferred from the first, giving, rapier to the second, receiving, rapier. Thefirst rapier is first accelerating from zero to full speed and then decelerating to zero again atthe tip transfer point. This type of motion is analogous for the second rapier. This leads to ayam tension that goes from loW to high and then back to loW again. In fact, When the rapierdecelerates the mass in the yam causes it to move faster than the rapier itself causing asurplus of yam. This effect increases With the yam count, i.e. the yam Weight per lengthunit, and is a real problem for coarse yams and fast machines. In order to solve this problem passive or controlled yam brakes are being used.

If the machine speed is to be increased, the mechanical arrangement for the rapiermechanism must be made as light as possible. On the other hand, higher speeds means higher yam tension Which requires a more rigid and stronger rapier system.

Weaker yams are cheaper and are thus attractive to use. Weaker yams have less tensilestrength and if a too high brake force is applied in order to control the balloon, or to giveenough tension for the rapier fianction, the risk for yam break is increasing rapidly. GB1355687 describes a yam feeder Where a member directly connected to the Weavingmachine moves back and forth to remove yam in unison With the movement of the rapierfrom a yam package during both a forward and retum movement of the rapier. Hereby, the speed at Which the yam is draWn from the yam package can be reduced to one half.

In US 3825198 a yam storage is described. The yam storage is forrned by a container andhas an endless belt for advancing the yam in the container. The yam storage is used to rid strip shaped materials from electrostatically charged materials.

There is a constant desire to improve yarn feeding to textile machines. Hence, there is a need for an improved yam feeding device.

SIHVIMARYIt is an object of the present invention to provide an improved yam feeding device and yam feeding arrangement.

This object and/or others are obtained by the yarn feeding device as set out in the appended claims.

As has been realized, it Would be advantageous to reduce the speed at Which yam is draWnfrom a yam storage, such as a bobbin or a pre-Winder to a textile machine. This Wouldreduce the various forces required to cope With When increasing the speed of the textilemachine, in particular When a coarser yam having a relatively high Weight per length unit isused such as Jute, some synthetic yams or carbon fiber. Another desire is to provide yam feeding that reduces the yam tension.

Also While the device described in GB 1355687 allows for a reduced speed at Which theyam is draWn from the yam feeder, it has limitations and drawbacks. First the device of GB1355687 has a limitation in that the speed reduction can only be 50% and not more. Also,the fact that the member is directly connected to the Weaving machine and moves back andforth to remove yam in unison With the movement of the rapier from a yam package duringboth a forward and retum movement of the rapier makes it impossible to draW yam from theyam storage When the rapier is not moving such as during beat up. In other Words in GB 1355687 it is only possible to draW yam from a yam storage When the rapier is moving. As a result a significant fraction of the time available during a weaving cycle is not used todraw yam from the yam storage. This is because during a significant fraction of the weavingcycle the rapier(s) is/ are typically not moving. Second, the device moves in unison with therapier. This results in that the speed at which the yam is drawn from the yarn feeder isdirectly proportional to the speed of the rapier and hence varies signif1cantly during a cycleof a rapier machine. The fact that the device moves in unison with the rapiers as it ismechanically coupled to the rapiers in the weaving machine limits the functionality as it isnot possible to improve the function by following other movements in the weaving machinein order to even out the speed even more and/or compensate for other movements in theweaving machine. Third, the device requires a traveler guided along a rail, which imposesadditional friction forces and a moving part, which could be a disadvantage in some applications.

In a traditional pre-winder the yam is drawn from a cylindrical drum. At high speeds theyam will form a take-off balloon, which increases the yam tension significantly. With acoarse yam this ballooning effect will be accentuated and the yam tension thereby raiseseven more. It is therefore desired to provide a yam feeding device that will not be limited orat least less limited with regard to high speeds for, in particular, coarse yams. This wouldthen enable a higher productivity of a textile machine fed from the yam feeding device. Thehere described yam feeding device does not store the yam on a cylindrical drum but insteadstores the yam lying freely in a meandering pattem. Since the yam is not drawn from adrum but instead from yarn lying flat, the yarn take-off balloon from traditional pre-winderswill not be formed. The result is a much lower yarn take-off tension and that the speed ofthe textile machine can be increased to ultimately increase the productivity of the textile machine.

In accordance with one embodiment a yam feeding device for feeding yam to a textilemachine is provided. The yam feeding device comprises a moveable yam carrier adapted to transport yam in a first, forward direction and a loop former adapted to draw yam from a yam storage. The yam feeding device further comprises moveable loop keeping membersarranged at both sides of an input section of the moveable yam carrier, Wherein the loopformer is adapted to position yarn on the moving loop keeping members by moving the yamfrom side to side. The movement can comprise a movement being predominantlyperpendicular to the first direction. The moveable loop keeping members are adapted tohold the yam positioned thereon and to release the yam onto the moveable yam carrier in ameandering pattem at an input area of the moveable yam carrier and the yam lying on themoveable carrier is adapted to leave the moveable yam carrier at an output section of themoveable yam carrier. Hereby a yam buffer is formed that can draW yam from a yamstorage at a loW speed and Which can keep a large yam buffer that can supply yam to a textile machine With loW or in some instances practically no yam tension.

In accordance With one embodiment the moveable loop keeping members are pins. The pinscan be cylindrical or in one embodiment semi-cylindrical. Hereby a yam can easily be placed on and leave the moveable loop keeping members.

In accordance With one embodiment the moveable loop keeping members are locatedlaterally outside the moving carrier. In an altemative embodiment the moveable loop keeping members are located proj ecting through the moveable carrier.

In accordance With one embodiment at least one sensor is provided to detect the yam on the moveable carrier. Hereby input to a control mechanism can be provided.

In accordance With one embodiment a controller adapted to control the drive of the yamfeeding device in response to one or more pre-deterrnined parameters. The pre-deterrnined parameters include one or many of sensor signals and input from the Weaving machine.

In accordance With one embodiment at least one endless belt distanced from the moveable carrier and moving in parallel With the moveable carrier is provided. Hereby an improved control of the yam lying on the moveable carrier can be obtained. Further a first yarnmovement restriction means can be provided on such a belt moving in parallel With the moveable carrier.

In accordance With one embodiment the moveable carrier is an endless belt. Hereby an efficient carrier can be obtained that is easy to control.

In accordance With one embodiment an outlet yam guide is provided at an end section of themoveable carrier, the yam guide being located at a flat section of the moveable carrier.Hereby improved control of yam about to leave the moveable carrier is achieved. Inaccordance With one embodiment a second yam movement restriction means are providedand adapted to prevent yam from leaving the moveable carrier in an uncontrolled Way. Themovement restriction means can advantageously be located at an end section of the moveable carrier.

In accordance With one embodiment a spring biased element can be provided to press yamagainst the loop keeping member from the outside of the loop keeping member. Hereby the yam can be kept in place While being moved by the loop keeping members.

In accordance With one embodiment a slip feed device can be located before the yam feeding device.

The invention also extends to methods for controlling a yarn feeding arrangement inaccordance With the above and to a controller and computer program product for controlling the yam feeding device in accordance With the above.

BRIEF DESCRIPTION OF THE DRAWINGSThe present invention Will now be described in more detail by Way of non-limiting examples and With reference to the accompanying draWings, in Which: - Fig. l is a view illustrating a yam feeding arrangement, - Fig. 2 is a view in perspective of a yam feeding device, - Fig. 3 is a view of a yam feeding device comprising a pair of upper belts, - Figs. 4a and 4b are different views illustrating placing yam in a meandering pattern onto amoveable yam carrier of a yam feeding device, - Fig. 5 is a view illustrating a moveable yam carrier in accordance with one embodimentwith pins projecting through the moveable yam carrier, - Fig. 6a and 6b are different views showing the end section of a moveable yam carrier, - Fig. 7 shows the general principles of a slip feed device.

- Fig. 8 shows a yam feeding arrangement with a slip feed device, - Fig. 9 is a flow chart illustrating different steps perforrned when forming a yarn buffer,- Fig. 10 is a view of a controller, and - Figs. lla and llb illustrates further embodiments of a yam feeding device.

DETAILED DESCRIPTION In the following a yarn feeding arrangement for a weaving machine will be described. In thefigures, the same reference numerals designate identical or corresponding elementsthroughout the several figures. It will be appreciated that these figures are for illustrationonly and are not in any way restricting the scope of the invention. Also it is possible tocombine features from different described embodiments to meet specific implementation needs.

If the yam is fed to a weaving machine from a long loose buffer of yarn, the yam tensionwill be very low during insertion in to the weaving machine. The buffer of yam can forexample be formed by a number of consecutive loops forrning a meandering piece of yam that can be used during insertion in to the weaving machine.

In Fig. 1 an exemplary yam feeding device 16 for providing a yam buffer is shown. Theyam feeding device 16 draws yarn 40 from a yam storage, here represented by a pre-winder14. Yam can also be drawn directly from a bobbin (not shown). The yam from the yarnfeeding device 16 is supplied to a weaving machine 10, here represented by a rapierweaving machine. However, the yam feeding device can be adapted to feed any type ofweaving machine such as an air-j et weaving machine, a water jet weaving machine or a projectile weaving machine, as well as any other suitable type of textile machine.

The yam can thus be taken either directly from a bobbin, or from a conventional pre-winderby the yarn feeding device 16. A loop former 18 of the yam feeding device 16 Winds theyam onto moving loop keeping members, e. g. pins provided on the yam feeding device. Theloop former 18 can be of any suitable design. The loop former 18 will move the yam fromside to side and provide the yam to the loop keeping members 20. The movement of theloop former can be in a direction essentially perpendicular or at least predominantlyperpendicular to the movement of the loop keeping members. The movement of the loopformer can however in some embodiments deviate from a side to side movement only tobetter position the yam on to the loop keeping members. The drive of the yam feedingdevice 16 including the drive of the loop former 18 of the yam feeding device 16 can inaccordance with some embodiments be controlled by a controller 19. The controller 19 canin accordance with some embodiments receive input signals from different sensors generallyrepresented by a sensor 17 in Fig 1, and also from the weaving machine 10. This will be described in more detail below.

In Fig. 2 some parts of the yarn feeding device 16 are shown in more detail. In Fig. 2 themoving loop keeping members 20 are shown mounted on a roller 22. The moving loopkeeping members 20 are moved forward at the same speed as a yarn carrier 24 on which theyam leaving the moving loop keeping members is laid out. The carrier 24 can beimplemented in different ways. For example the carrier can be one or several endless belts, caterpillar tracks or similar. In Fig. 2 one endless belt is used as a yarn carrier 24 and is driven by the roller 22, which means that the yam carrier 24 in this case is driven insynchronism with the loop keeping members 20. The roller is in turn driven by a motor 21.The motor 21 can in particular be a controlled motor. The moving loop keeping members 20are located and driven in a manner to be accessible for the yarn to be wound by the loopformer 18 onto the moving loop keeping members 20. The loop former can be driven by aseparate motor 23. In particular the motor 23 can be a controlled motor. The yam issubsequently released or disengaged from the loop keeping members 20 at a later stage forexample by the moving loop keeping members following the roller to get undemeath theyam carrier 24. When the moving loop keeping members are moved under the carrier theyam will be pushed off the moving loop keeping member and lie free on the carrier. Theloops are transported forward in a downstream direction as the carrier 24, in this exemplaryembodiment a belt, is driven forward, thus making space for new loops upstream.Downstream the loops are consumed by the weaving machine.

Different yams will behave in different ways once placed on the carrier as the yam isreleased from the moving loop keeping members. Some yams will stay on the carrier in thesame or essentially the same position as the yam is placed on the carrier. Other yams have atendency to twist or move and cause snarls or entanglement when released from the movingloop keeping members. In order to prevent that the yam moves in an undesired manner, the yam can be held in position on the carrier by a position keeping means.

In Fig. 3 an exemplary embodiment where the position keeping means is formed by a belt ormultiple belts. In the embodiment depicted in Fig. 3, where the carrier 24 is a belt (a first,lower, belt), a second, upper, belt 26, moving mainly synchronously with the first belt, canbe provided. The second belt can be arranged as two parallel belts as shown in Fig. 3. Thesecond belt 26 is located above the first belt slightly distanced from the first belt to makeplace for the yam to be placed in-between the first and second belts. If the distance betweenthe first and second belts is small enough the yam has no space to twist or otherwise makeundesired movements. Hence, the distance is preferably smaller than the natural bending radius of a twisting yarn. However, the distance must be big enough to fit the yam at the _10- thickest portion of the yam, including knots and splices. In accordance with some preferred embodiments, but not limited to, the distance can be set to be between l and 6 mm.

In accordance with some embodiments the moving loop keeping members 20 are pins. Suchan embodiment is shown in Fig. 3. The pins 20 can be placed outside the belt or belts 24, 26.The yam will after release from the pins 20 lie smoothly on the belt 24. When the yam iswound on the pins 20 the yam will be stretched between the pins. Once released from thepins 20 the yam 40 is no longer stretched between the pins 20 and will form loops lying on the belt 24 in a meandering shape.

In an altemative embodiment the moving loop keeping members such as pins 20 can insteadof being placed outside the belt as an altemative be placed in the belt or caterpillar track or asimilar carrier. In such an embodiment a slot 28 (in f1g 5) big enough to allow the pin to project through the belt 24 without contacting the belt can be provided.

If the pins are moving in slots, the slot length limits the relation of pin height over the beltand the distance between each pin. For this reason it can be advantageous to place the pinsoutside the belt. In Fig. 4 a view illustrating how the loop former 18 wounds yarn 40 ontopins 20 located outside the belt 24 is shown. The loop former 18 winds yam around one pin20 at one side of the belt 24 and then travels with the yam to a pin 20 on the other side ofthe belt 24. This winding by the loop former continues as the pins moves forward to continuously generate a meandering buffer of yam lying on the carrier.

In Fig. 5 a view illustrating a belt where the pins 20 are located in the belt is shown. Thebelt is provided with slots 28 to allow the yarn to disengage from the pins. Fig. 5 furtheralso illustrates the limitation with regard to possible pin length/ pitch.

Further, as is known some yams are livelier than other yams. To keep such lively yams under control movement restriction means such as brushes and clamps can be used. Such _11- movement restriction means can be fixed to the upper belt if one is provided, or to any othersimilar arrangement provided to move at the same speed as the carrier that transports theyam of the yam buffer. In Fig 3 such a movement restriction means 29 is shown. The yamis pressed between the movement restriction means and the carrier. An arrangement withmovement restriction means can also serve to brake the front part of the yam loops at thedeceleration of a rapier movement in the weaving machine, or at the end of weft insertion ofan air-j et or waterj et weaving machine. The properties of the movement restriction meanscan in accordance with some embodiments be adapted to a specific weaving application. Forexample, if a heavy yam is used, the stiffness and/or pressure of the movement restrictionmeans can be selected to be comparatively high, and if a thin yam is used the stiffnessand/or pressure of the movement restriction means can be selected to be comparatively low.The movement restriction means can be of various sizes. For a yam with a high requirementwith regard to controlling the yam, the movement restriction means can be long, extendingfrom one side of the carrier to the other, or be continuous following the carrier in themoving direction. For other yams small movement restriction means placed with distancefrom each other can be enough to obtain suff1cient control of the yam on the carrier. As theprovision of movement restriction means will increase the yarn take-off tension from theyam feeding device, it is typically preferred to provide as few movement restriction meansas possible with as little force against the yam as possible while obtaining the desired control of the yam.

The yarn feeding device l6 is controlled to be driven in synchronization with the weavingmachine to which it supplies yam. The yam buffer formed by the yam feeding device iscontrolled to always have a buffer of yam that can be inserted into the weaving machine. Inother words there will always be some amount of yam placed on the carrier during operationof the yam feeding device when feeding a weaving machine. The length of yam stored onthe carrier can be adapted to the speed, the weft pattem and the width of the weavingmachine. The width of the loops in the meandering yam on the carrier, the pitch between each loop and the number of loops possible to store on the carrier deterrnines the length of _12- yam possible to store in the yarn feeding device. The loop former can be set to wind yarnonto the moving loop keeping members at a speed synchronized with the drive speed of thecarrier such that the yam on the carrier is moved forward at the speed at which yam iswound onto the moving loop keeping members. The speed at which the yam is wound ontothe moving loop keeping members can be deterrnined in several ways. A stand-alonesolution is to have one or more sensors detecting the yam front on the belt. The sensor(s)can for example detect the position of the yam buffer front edge, the amount of yam takenoff from the yam feeding device or similar information. In particular yam can be woundonto the moving loop keeping member at the same average speed as the yam leaves the yamfeeding device. In an altemative embodiment communication with the weaving machine canbe used. Data is fed from the weaving machine. The data can comprise one or more ofweaving machine width (pick length), speed (rpm), start & stop of the weaving machine,weft pattem in advance etc. The speed at which the yam is wound onto the moving loopkeeping members is then deterrnined based on data received from the weaving machine. In afurther altemative embodiment the yam wind on speed control is based on information from both one or more yam sensors and data received from the weaving machine.

The sensor(s) used in the yam feeding device can be of several types, e. g. optical,mechanical or capacitive. The sensor(s) can be of point type or an array. Altematively a camera can be used as a sensor.

In accordance with one embodiment where an upper belt is provided, the upper belt can bemade as two or more separate belts running side by side at the same speed. The sensor(s)can then be placed in a gap formed between the multiple upper belts. Altematively, the beltscan be more or less perforated, even a mesh structure is envisaged. Hereby the sensors can be adapted to register the yam from both sides.

The lower belt could potentially be a problem for some sensor types. If for example an optical sensor is used, it may be difficult for the sensor to see the difference between a yarn _13- and the belt. In accordance with one embodiment two or more belts are provided as lowerbelts and a sensor is located in a gap between the belts. Hereby the quality of the sensor output signal can be improved.

The drive of the yarn feeding device 16 including the loop forrner 18 can be made by one ormore electrical motors. The motors can be individually controlled. If one motor is used, the different drives for the moving parts such as a belt or belts and the loop former can be madevia mechanical connections. If separate motors are used, they are advantageously controlled to be driven in synchronization with each other.

The yam feeding device l6 can be run in single color, weft mix or in free pattem. If a lowyam tension is desired at a location upstream the yam feeding device, it can beadvantageous to run weft mix of two or more channels so the time to fill the loop buffer is longer, thereby lowering the yam speed and tension in to the yarn feeding device.

As the carrier is moving forward to fill up the buffer of the yam feeding device also whenthe weaving machine connected thereto is not inserting yam, for example during beat up, orwhen another channel is inserted, the belt can continue to feed the yam out from the carrierunless this is prevented. One way to prevent this from happening is to provide an outleteyelet 34, stationary or movable, before the carrier ends. By doing this the front yam will beprevented from leaving the carrier and hold back the following loops. For example, when aweft insertion is finished, the yarn buffer is continuously filled up and moved forward bythe carrier 24. The moving carrier will then transport not only the yam loops in the bufferbut also the yam that is between the front loops of the buffer and the weaving machine. Toprevent the yam from leaving the carrier in an uncontrolled way, or even to fall downcompletely from the carrier, a second yam movement restriction means can be used. Such asecond yam movement restriction means 32 is shown in Figs. 6a and 6b, where the movement restriction means are exemplified by a brush. Also shown in Fig. 6a and b is an _14- output guide/ eyelet 34 via which the yam leaves the yam feeding device 16 to be inserted in to the weaving machine.

Also brake members, e. g. brushes might be placed at the sides of the lower belt to preventthe sides of the loops to be pushed off the belt. Another possibility is to use at least oneactive member to replace (reshape) some part of the yam. Such actions to control the yamlocated on the carrier can, but need not, be done controlled by input signals from one or more sensors provided.

To lower the yam tension in to the yam feeding device, a slip feed device can be placedbefore the yam feeding device. The slip feed device is a driven roller that rotates with aperipheral speed that is higher than the necessary yam speed. Such a device is described inUS 5660213. When the yarn feeding device pulls the yam during the loop formation, theyam will be pulled against the roller and the friction between the yam and the rotating rollerwill contribute to pull the yam further thus decreasing the yam tension. As soon as the rollergives more speed to the yam than what is consumed by the yam feeding device the forcefrom the yam against the roller will decrease and hence the pulling force will also decreaseuntil a balance is reached and the roller will not give any further force to the yam. Fig. 7 depicts an exemplary slip feed device 38 in two different views.

Using a slip feed device in the yam feeding device as described herein can lower the yarntension substantially. In Fig. 8 a set-up with a slip feed device 38 before the yam feedingdevice 16 is depicted.

In Fig. 9 a flow chart illustrating some steps when controlling a yam feeding device (16)feeding yam (40) to a weaving machine (10) is shown. First, in a step 501, yarn is drawnfrom a yam storage using a loop former. The yam can be drawn from a pre-winder ordirectly from a bobbin or via a slip feed device. Next, in a step 503, yarn is placed in a meandering pattem on a moveable carrier by positioning the yarn on to moving loop _15- keeping members using the loop former. The loop former positions the yarn on the movingloop keeping members by moving the yarn from side to side in a direction perpendicular toa first direction. The moveable carrier and the moving loop keeping members can bedesigned as described above. The yarn is then in a step 505 transported in the first, forward,direction using the moveable carrier. The yarn lying on the moveable carrier then leaves themoveable carrier at an end section of the moveable carrier in a step 507 to be inserted into the Weaving machine.

In Fig. 10 a controller 19 for controlling a yam feeding device 16 is depicted. The controller19 can comprise an input/output 81 for receiving input signals for parameters used forcontrolling the yam feeding device as set out above. For example the input signals can bevarious sensor signals from sensors of the yam feeding device. For example, sensor signalscan be provided from any type of sensor, e. g. optical sensors, mechanical sensors orcapacitive sensors. The sensors can be of point type or an array of sensors. Altematively acamera can be provided to feed input signals to the controller. Also signals from theWeaving machine can be input to the controller 19 and used to control the yam feedingdevice. In particular input data from the Weaving machine can comprise one or more ofWeaving pick length, speed (rpm), start & stop of the Weaving machine, pattem in advanceand similar input data. The input/output 81 outputs motor control signa1(s) to controlledmotors of the yam feeding device. The controller 19 further comprises a micro-processorthat also can be referred to as a processing unit 82. The processing unit 82 is connected toand can execute computer program instructions stored in a memory 83. The memory 83 canalso store data that can be accessed by the processing unit 82. The data in the memory cancomprise pre-stored data relating to the Weaving machine 10. The computer programinstructions can be adapted to cause the controller to control the yarn feeding devicecomprising a motor in accordance With the teachings herein. The controller can be located atany suitable location. For example the controller 19 can be integrated in a motor of the yamfeeding device. The controller 19 can input output data using any suitable means. Both Wireless and Wireline communication devices can be used. _16- The above examples are for illustration only. Numerous modifications can be envisaged andthe different embodiments can be combined to meet specific implementation needs. Forexample the moving carrier has been illustrated to be moving yam horizontally. It is alsopossible to move the yam vertically by providing restrictions means to keep the yam inposition during transport on the carrier. Further, in the above examples the loop keepingmembers 20 are shown as generally cylindrically shaped pins. However, other loop keepingmembers are also envisaged such as hooks or other elements suitable for engaging the yamand bring it forward. In Figs l la and l lb an embo diment where the loop keeping members20 are formed as semi-cylindrical pins is shown. Using semi-cylindrical pins it is possible toincrease the radius of the pins without adding to the space required. Further, a spring biasedelement 65 can be provided to press the yam against the loop keeping member from outsidethe loop keeping member to keep the yam better in place once placed on the yam keepingmember until the yam is released from the loop keeping member. The spring biased element 65 can for example be a thin, resilient, metal plate or a similar element.

Using the yam feeding device as described herein will provide numerous advantages. Forexample the yam tension in to a textile machine can be made very low. Also, if a pre-winderis used, the ballooning problem that occurs using a conventional pre-winder is stronglydecreased. Generally the maximum take-off speed from a yam storage can be significantlydecreased. Multiple yam feeding devices can be used when running a weaving machine in weft mix whereby the yam speed from the yam storage can be further reduced.

Claims (19)

1. l. A yam feeding device (16) for feeding yam (40) to a textile machine (10), the yamfeeding device comprising: - a moveable yam carrier (24) adapted to transport yam in a first, forward direction, - a loop forrner (18) adapted to draw yarn from a yam storage (14), - moveable loop keeping members (20) arranged at opposite lateral sides of an input section of the moveable yam carrier, Wherein the loop former is adapted to position yam on the moving loop keeping members by moving the yam from side to side, Wherein the moveable loop keeping members are adapted to hold yam positioned thereonand to release yarn onto the moveable yam carrier in a meandering pattem at an input area of the moveable yam carrier and; Wherein the moveable yam carrier comprises an output section, from Which output section yam lying on the moveable carrier is adapted to leave the moveable yam carrier.

2. The yam feeding device according to claim l, Wherein the loop former is adapted toposition yam on the loop keeping members using a movement being predominantly perpendicular to the first direction.

3. The yam feeding device according to claim 1 or 2, Wherein the moveable loop keeping members are pins (20).

4. The yam feeding device according to claim 3, Wherein the pins are semi-cylindrical. _18-

5. The yam feeding device according to any of claims 1 - 4, further comprising a springbiased element (65) provided to press yam against the loop keeping member from the outside of the loop keeping member.

6. The yam feeding device according to any of claims 1 - 5, Wherein the moveable loop keeping members are located laterally outside the moving carrier.

7. The yam feeding device according to any of claims 1 - 5, Wherein the moveable loop keeping members are located proj ecting through the moveable carrier.

8. The yam feeding device according to any of claims 1 - 7, Wherein at least one sensor (17) is provided to detect yarn on the moveable carrier.

9. The yam feeding device according to any of claims 1 - 8, further comprising a controller(19) adapted to control the drive of the yam feeding device in response to one or more pre- deterrnined parameters.

10. The yam feeding device according to claim 9, Wherein the pre-deterrnined parameters comprises sensor signals.

11. The yam feeding device according to claim 9 or 10 Wherein the pre-deterrnined parameters comprises input from the textile machine.

12. The yam feeding device according to any of claims 1 - 11, further comprising at leastone endless belt (26) distanced from the moveable carrier and moving in parallel With the moveable carrier.

13. The yam feeding device according to claim 12, Wherein said at least one distanced endless belt comprises a first yarn movement restriction means (29). _19-

14. The yam feeding device according to any of claims 1 - 13, Wherein the moveable carrier is an endless belt.

15. The yam feeding device according to any of claims 1 - 14, further comprising an outletyam guide (34) at an end section of the moveable carrier, the yam guide being located at a flat section of the moveable carrier.

16. The yam feeding device according to any of claims 1 - 15, further comprising a secondmovement restriction means (32) located at an end section of the moveable carrier, Whichsecond yam movement restriction means (32) is adapted to prevent yam from leaving the moveable carrier in an uncontrolled Way.

17. A yam feeding arrangement comprising a yam feeding device according to any ofclaims 1 - 16, the arrangement further comprising a slip feed device (38) located before the yam feeding device.

18. A method of controlling a yarn feeding device (16) feeding yam (40) to a textilemachine (10), Wherein yam is inserted into the textile machine, the method comprising: - draWing (501) yarn from a yam storage (14), using a loop former (18), - placing (503) the yarn in a meandering pattem on a moving carrier by positioning the yarnon to moving loop keeping members provided at both sides of a front section of the movingcarrier, Wherein the loop former positions the yarn on the moving loop keeping members bymoving the yarn from side to side., - (505) transporting yam in the first, forward, direction using the moving carrier (24), - letting (507) the yarn lying on the moveable carrier leave the moving carrier at an output section of the moveable carrier. _20-

19. A computer program product comprising computer program code adapted to, Whenexecuted on a computer causes the computer to control a yam feeding device in accordance With claim 18.