EP1819857A2

EP1819857A2 - Thread feeding device with return operation

Info

Publication number: EP1819857A2
Application number: EP05802281A
Authority: EP
Inventors: Rolf Huss
Original assignee: Memminger IRO GmbH
Current assignee: Memminger IRO GmbH
Priority date: 2004-10-21
Filing date: 2005-10-06
Publication date: 2007-08-22
Anticipated expiration: 2025-10-06
Also published as: WO2006045411A3; TW200632167A; JP2008517179A; WO2006045411A2; EP1819857B1; US7591153B2; BRPI0516241A; JP4255504B2; CN101044276B; DE102004051520B4; BRPI0516241B1; TWI372194B; IL181953A0; CN101044276A; KR20070070180A; DE102004051520A1; US20070210198A1

Abstract

A thread feeding device (1) comprises a thread regulator (4) with a drive device (3), and comprises a thread store (22) with a thread laying element (21), which has its own thread laying element drive device (27). A control device (11) controls both drive devices (3, 27) in such a manner that, on the one hand, only positive operation of the thread regulator (4) and, on the other, a thread withdrawal is made possible when the knitting machine oscillates. In addition, this configuration enables an improvement to the dynamics of a thread feeding device (1).

Description

Yarn feeding device with return operation

The invention relates to a yarn feeding device, which is especially designed for use on knitting machines or other yarn-consuming machines which return yarns. Such machines are, for example, flat knitting machines with a reciprocating carriage, wherein a short return of the yarn can occur at least at one of the carriage reversal points. Thread return can also occur in flat-knit masks if they have multiple knitting locks and threads, of which individual can be switched inactive for one or more strokes. Excessive yarn returns can also occur on circular knitting machines, especially in the so-called fully-fashioned technique. In this technique wer¬ not only threads and interpreted, but it may be necessary in certain knit sections to rotate the knitting cylinder more or less one or more times backwards. This process, in which the knitting cylinder is repetitively rotated forwards and backwards, is called "oscillation." It can come to the yarn return delivery of half a meter of thread and more.The Fadenliefer¬ devices must consider such yarn return delivery.

From DE 40 32 402 C2 a memory tour guide for use on flat knitting machines is known, which is combined with a separate dynamic yarn storage. The yarn coming from the storage feeder is fed to the flat knitting machine via a yarn store. The Fa¬ memory is formed by a long torque beaufschlag¬ th lever, at its free end a thread eyelet is formed. The lever is pivotally mounted. In addition, a yarn brake and a fiber tension sensor are arranged in the yarn path. The amount of thread returned during the carriage reversal is absorbed by first closing the controlled thread brake, so that no further thread can be withdrawn by the storage specialist. Then the pivoting lever is acted upon by torque, so that it absorbs the thread returned by the thread guide of the flat knitting machine by drawing an acute-angled thread loop into the length.

When the carriage is reversed again, this thread supply is used up and then the thread brake is released again in order to pull the thread away from the store feeder. This type of thread storage is suitable, in particular, for memory tour guides, in whose use the knitting machine picks up the thread from the memory guide. However, this contradicts the principle of the knitting machine aimed at using positive feeders to allocate a predetermined amount of thread.

An intermediate storage of thread is also possible with the yarn delivery device according to DE 37 32 102 C1. This document discloses an electronically controlled positive feeder with a looped by the thread Fadenlieferrad. The thread running to the knitting machine is passed through a thread store. To this belongs an almost 360 ° swivel mounted lever, through whose end the thread runs. Within the circle described by the eyelet, a plurality of thread support elements are arranged, which define a polygonal thread store. If thread is left between the yarn feed wheel and the connected machine and is not picked up by the machine, this amount of yarn is deposited by the lever on the drum support elements.

This type of yarn delivery is particularly suitable for yarn delivery with a constant yarn tension.

Furthermore, DE 34 29 193 C1 discloses a device for winding or winding threads from or onto a yarn package, in which the yarn is guided on the yarn package by means of a winding finger. The winding finger sits on a shaft arranged concentrically to the yarn package, which is driven by an electric motor. The winding finger runs around the outer circumference of the yarn package. If necessary, the electric motor can be controlled in such a way that the yarn is unwound from the yarn package or even onto it is rewound. To control a thread tensioner is provided, with which the thread tension is checked. If there is a need for a return delivery, the winding finger winds the thread back until the thread tensioning roller is guided back into the normal position by the thread that is being tensioned.

Garnspulen are usually summarized on so-called Spulen¬ gates, of which the threads as needed, even over long distances only passively deducted wer¬. Inclusion of the yarn packages in the active winding and unwinding is hardly desired in many cases and with larger distances between the yarn package and the knitting machine also not possible.

On this basis, it is an object of the invention to provide a Fa¬ denliefergerät, which can handle occasional yarn returns in modern knitting machines or other textile machines.

This object is achieved with the yarn feeding device according to claim 1 or claim 19:

The yarn feeding device according to claim 1 has a yarn delivery wheel, which can be driven in two opposite directions of rotation by means of a drive device in order to convey the yarn. The thread run is essentially tangential. A first direction of rotation serves as a forward rotation in normal operation of the delivery of thread in the yarn delivery direction to a thread consumption point. The reverse rotation serves in return mode for the return of the thread, which comes back in the return direction of the thread consumption point. This is then rewound onto the yarn feed wheel. Thread becoming free on the inlet side of the thread delivery wheel is buffered in a thread store. finished This is arranged with respect to the normal yarn feeding direction before the yarn feed wheel. It can be present between a possibly existing thread brake and the yarn feed wheel. The arrangement of the thread store in front of the delivery wheel and in the immediate vicinity of the same makes on the one hand the direct delivery relationship between the yarn delivery wheel and the knitting machine so that the yarn delivery wheel of the knitting machine can allocate or remove the desired amount of yarn, and on the other hand the yarn is stored without appreciable influence on the tension in the filament winding and in the section between Fadenlie¬ ferrad and thread consumption parts.

The yarn storage preferably has a concentric to the yarn feed wheel arranged yarn storage surface, either as a contiguous, uninterrupted surface or as a discontinuous surface, for. B. in the form of several individual surfaces may be formed. The individual surfaces can be, for example, support areas of pens or the like. The arrangement concentric with the yarn feeding wheel enables uniform winding and unwinding of the yarn returned by the yarn feeding wheel on its inlet side with a uniform tension. Preferably, the Fa¬ memory is associated with a thread-laying, which hangs the thread coming from the yarn feed on the storage surface and decreases from this again. The thread-laying device can be formed by a thread-guiding eyelet which, for example, is guided by a suitable lever on a circular path which is concentric with the yarn feeding wheel. This arrangement allows a uniform winding and unwinding of the thread without significant voltage fluctuations. Especially with elastic threads is thus avoided that the thread is cached with different strains. It also prevents the thread from coming off the thread. Memory is again performed on the yarn feed wheel, there with different, ie fluctuating voltages, running in the winding on the yarn feed wheel. Overall, the concentric arrangement, as described above, thus benefits the knit quality.

The thread-laying device is preferably assigned a thread-laying drive device, which is independent of the drive device of the thread-supplying wheel. For example, both drive devices are formed by electric motors. Both electric motors can be controlled by a control device which moves the thread feeder and the yarn delivery wheel in a coordinated manner. In this case, the control device preferably differentiates between several operating states, e.g. according to claim 9. Thereafter, the control device allows the suture layer and the yarn feeding device in Rückholbetrieb rotate with matched speeds backwards, so that the retrieved thread is stored on the thread storage without new thread is drawn into the thread store. When returning to normal operation, the yarn reserve formed in this way is first of all used up, with the yarn feed wheel and the yarn feeder rotating forward with coordinated rotational speed. If the thread reserve is used up, the thread feeder remains z. B. are in a fixed position, the yarn feed wheel unwinded further rotates forward. From the moment the stand thread stops, the thread feed wheel then picks up the thread from the yarn package.

The advantage of this device is that a connected knitting machine can commute as often as desired without consuming thread. The thread is unwound at each shuttle on the thread store and from this again. The speed of the thread leveler and the Fadenlieferrads are coordinated so that no thread is made up by the yarn package, so that the total amount of yarn present in the yarn feeding device does not increase. With the oscillation of the knitting machine, the amount of yarn of the yarn feeding device oscillates between a maximum value and a minimum value, whereby these may differ by more than one meter.

The drive device of the yarn delivery wheel and the thread-laying drive device are each formed by an electric motor, preferably a position-controlled electric motor. As an alternative, however, it is also possible to provide a gearbox and a coupling device between the yarn delivery wheel and the yarn feeder, in order to connect the yarn feeder to the yarn feed wheel in each case with a variable speed when filling and emptying the yarn store. The thread-laying drive device is formed in this case by a transmission clutch brake combination. Be¬ preferred, however, because of the better controllability of the own electromotive drive of the thread leveler.

Preferably, the yarn feed wheel is driven in normal operation at a predetermined speed. The predetermined speed can be derived from the operating speed or speed of the knitting machine. It is desirable to operate the yarn delivery wheel and the knitting machine synchronously in a predetermined speed ratio. This operation is called positive operation. The yarn delivery wheel distributes the desired amount of yarn to the knitting machine and thus determines the mesh size of the knitted fabric. To compensate for dynamic processes when Star¬ th and stop the Fadenlieferrads a yarn store with low storage capacity between the yarn feed wheel and the knitting machine can be provided. This thread but rather does not serve the caching zurückgehol¬ th thread. In any case, its capacity is insufficient. It is only intended to buffer voltage spikes, which otherwise might occur during switch-on processes (starting and stopping of the yarn feed wheel). In the simplest case, this thread store is formed by a thin, light and resilient lever which holds a thread loop.

When retrieving thread can also be worked with a given Fadenlieferraddrehzahl. However, it is preferred to act on the thread return voltage controlled, i. under control of the thread tension. As a result, the yarn feeding device is constantly switched over between positive operation and voltage-controlled operation during oscillation of the knitting machine (positive delivery for normal operation and voltage regulation for return operation).

Both the thread layer and the yarn feed wheel are preferably connected to angle encoders. The Steuereinrich¬ device is preferably provided with a counter or other monitoring device that counts the traversed by the Fadenle¬ ger angular steps and preferably also by the yarn feed wheel in particular during retrieval operation continuous angle steps. Alternatively, the traversed by the thread layer as well as the yarn feed angle can also be registered in other ways. The control device monitors in this way the amount of thread buffered in the thread store. In normal operation, it can switch over with a stationary thread layer if the entire forward registered path has been traversed backwards or, alternatively, if the thread layer has reached a predetermined position of fixation. Approaching this fixed position, the suture layer can move from its normal speed gradually slowed down to its speed Mull to avoid jerky thread tension changes on the inlet side of the yarn feed wheel. The thread running on the Faden¬ yarn is relieved in this way. In cooperation with the pattern memory of the knitting machine, it can be ensured that this gradual deceleration occurs only when the oscillation operation is terminated in order to avoid an otherwise occurring gradual filling of the yarn storage device.

The control of the yarn feeding device is preferably carried out by the machine control, in particular its pattern memory. This supplies the data on the quantities of yarn to be supplied, which correspond to the yarn feed wheel speeds, as well as the times for delivery start and end of delivery. The yarn feeder converts these values as error-free as possible. It is also possible to operate the yarn feeding device self-learning. For this purpose, e.g. the thread tension is held voltage-controlled at a nominal value during trial operation. The Fadenlieferraddrehzahlen all Fadenlie¬ ferräder all active yarn feeding devices are monitored and it is a suitable mean value determined as the desired value for the later positive operation.

In addition, it is possible to monitor the self-adjusting thread tensions by means of a yarn tension sensor during positive operation and, if this deviates from a desired value, to readjust elements of the knitting machine. The adjustment can also be limited to cases in which the deviation exceeds a threshold value. Nachzustellende elements of the knitting machine can be knitting locks or the goods deduction. It is also possible to dispense with an adjustment of the knitting machine or its elements and, in the event of exceeding or undershooting Given thread tension thresholds only an alarm signal or a shutdown signal to generate.

The suture layer can further be used to substantially improve the dynamics of the suture delivery wheel. It turns out, in fact, that with a sudden thread requirement from zero to high delivery speed not only the drive device and the yarn delivery wheel itself must be accelerated, but also the entire yarn from the yarn package to the yarn consumption point. Here, the thread is to accelerate and also stiction is overcome. The yarn running on the input side of the feed wheel brakes the yarn feed wheel. The acceleration of the same can be significantly improved if the suture accelerator just before such acceleration phase produces a smaller reserve of thread on the Fa¬ memory and if the suture with the start of Fadenlieferrads is also accelerated to the Fadenlieferrad first with thread from the thread store and to be supplied with thread from the bobbin only when approaching its fixed position. The yarn store serves to decouple the yarn feed wheel during its acceleration phase in terms of power from the yarn package.

It is also possible to prematurely start or stop the yarn feed wheel in anticipation of a sudden increase in the yarn requirement or drop in the yarn requirement (pattern in advance). In this way, the inertia of the yarn feed wheel and connected components can be compensated to a certain extent and the yarn tension peaks or yarn tension drops at the beginning and end of the supply can be reduced.

Further details of advantageous embodiments or developments are the subject of the drawing, the Description or claims. In the drawing, an embodiment of the invention is illustrated. It shows:

1 shows a yarn feeding device according to the invention in a front view,

FIG. 2 shows the yarn feeding device according to FIG. 1 in a longitudinal sectioned and partially schematized illustration; FIG.

3 shows the yarn feeding apparatus of FIG. 1 and 2 in a schematic perspective view,

4 shows the yarn feeding device according to FIGS. 1 to 3 in a schematic representation in normal operation, FIG.

5 to 9 the yarn feeding device of FIG. 4 in Rückholbe¬ drive in different positions and

10 shows the yarn feeding device according to FIG. 4 in a start-up preparation phase before normal operation.

In Fig. 1, there is illustrated a ply-feeding apparatus, e.g. for the supply of hard (less elastic) or elastic threads on flat knitting machines or circular knitting machines used. In particular, the Fadenlieferge¬ advises 1 for yarn delivery on knitting machines that have time-varying thread requirement and / or temporarily return thread. The yarn feeding device 1 has an e.g. Also evident from Figure 2 carrier 2, on which a drive means 3 is held for a yarn feed wheel 4. It is represented as a hexagon. In practice, it may also be mehrflüglig and, for example. to form a hexagon. The drive device 3 is formed, for example, by an electric motor 5, whose armature 6 is connected to a driven shaft 7, which carries the yarn feed wheel 4. In addition, it can, for example, be connected at its other end to an angle encoder 8, which serves to detect the current rotational position of the armature 6. The angle transmitter 8 or an associated electronic circuit 9 is connected to a control device 11 which serves to drive stator windings 12 of the electric motor 5.

The yarn feed wheel 4 is preferably constructed to be particularly sluggish in order to allow particularly large rotational accelerations. For this purpose, it has a number of wire clips 13, 14, 15 (and others without a separate reference symbol) oriented in different radial directions below one another. The wire hanger 13, 14, 15 are taken on a hub 16 which sits on the output shaft 7. They are each approximately U-shaped, wherein they have a central, straight section 17 for the thread winding and, in particular, on the side facing the drive device 3, a radially outwardly directed projection 18. This marked an inlet side 19 of the yarn feed wheel 4th On the inlet side 19 of the yarn feed wheel 4, a yarn feeder 21 is provided which belongs to a yarn store 22 ge. To the yarn store 22 also includes a here preferably frusto-conical from the yarn feed 4 away tapered thread storage surface 23, which is arranged to the An¬ drive shaft 7 concentric. It is preferably substantially shorter than the sections 17 of the wire brackets 13, 14, 15 in the axial direction of the drive shaft 7.

The thread interleaver 21 bridges the axial distance between the thread storage surface 23 and the inlet side 189 of the yarn feed wheel 4. made of ceramic tube 24 which forms a Fa¬ denöse. It is supported by a circulation lever 25, which is rotatably supported by means of at least one corresponding bearing 26 on the support 2 about a rotation axis concentric with the drive shaft 7.

The circulating lever 25 is assigned a thread-laying drive device 27 to which a preferably position-controlled electric motor 28 belongs. Its output shaft 29 is connected via a gear connection in the form of two gears 31, 32 with the circulation lever 25. The electric motor 28 is controlled by the control device 11. For this purpose, it is connected to signal lines 33 and control lines 34 for controlling its windings with the electric motor 28. Corresponding signal lines 35 and drive lines 36 are also present for the electric motor 5.

The thread-laying drive device may be assigned a locking device 37 for locking the circulation lift 25 in a fixed position. The Verriegelungsein¬ device 37 may be actuated by an electromagnet 38, which may be controlled by the control device 11 can. If the thread layer 21 is to perform more than one revolution, the locking device 37 is transferred to the release position, ie unlocked. For this purpose, for example, a An¬ striker pin 38a is provided, which is movable by the electromagnet 38 between a locking position and a stop position ^■.

On the carrier 2, a thread tension sensor 39 is also mounted, which serves to detect the tension of the running thread 41. It has a thread support pin 42 over which the thread 41 runs at an obtuse angle, it is connected to a corresponding force measuring device 43, which supplies a thread tension measured value to the control device 11 or any other suitable device. The Fa¬ denspannungssensor 39 can be seen in Figure 1 housed in a housing part 44, on the front side of a display 45 and a plurality of controls 46, 47 may be housed. The thread running path defined by the subhousing 44 and the thread support pin 42, as shown in particular in FIG. 2, is oriented in an obtuse angle to the axis of rotation of the yarn feed wheel 4.

As can be seen from FIG. 3, the suture layer 21 serves, in particular, to wind or unwind thread 41 on the thread storage surface 23. The thread 41 is guided before it reaches the thread storage surface 23 through a thread inlet eye 48. In this case, it can first pass through a yarn brake 49, which is illustrated only schematically in FIG. The yarn brake 49 is preferably a non-controlled yarn brake which adjusts a constant yarn tension. If necessary, however, their braking elements can also be acted upon by a controlled clamping force. For this purpose, the brake elements are, for example, with an electrical adjusting device (eg an electric motor or an electromagnet, a Piezostelleinrichtung or the like), which is controlled by the Steuerein¬ device 11. Preferably, this controls the yarn brake 49 so that the braking force is increased when the yarn layer 21 fills or empties the yarn store 22, while the braking force is reduced when the yarn store 22 is empty and the yarn delivery yarn positive to the knitting machine of follows the yarn package.

Before the yarn brake 49, an inlet stopper not illustrated in detail is preferably provided. This works preferably optically. But it can also be a ein¬ fold mechanical stop in the form of a mechanical feeler lever are provided. The thread monitoring in front of the yarn feed wheel 4 is preferred to the yarn feed behind the feed wheel 4. The yarn tension sensor 39 is less susceptible to thread monitoring because thread tension values of zero can occasionally occur even during normal operation. In addition, it should in any case be prevented that the end of a broken thread runs into the machine.

It is also possible to use the thread layer 21 as a stand-off, ie to monitor the thread. For this purpose, the force exerted by the thread on the thread layer force is monitored. If this drops to too low a value or zero while the yarn feeding wheel is running, this is rated as a fiber break. In practice, this can be realized, for example, by keeping the suture layer 21 away from the thread a few mm away from the abutment (pin 38a), but elastically holding it too taut on it. If the thread layer strikes the pin 38a, this is detected by a suitable sensor and evaluated as a thread break. The yarn feeding device of Figure 1 to 3 operates according to the following functional description:

The yarn feeding device distinguishes several types of operation. In FIG. 4, normal operation is shown. For the clarification of the circumstances, a largely abstract representation was chosen. The yarn storage surface 23 is initially shown only by dashed lines to distinguish the surface with thread and surface without thread. Of the yarn feed wheel 4 is seen in all Figures 4 to 11 only a single wire bow 14 for better traceability of the rotation of the yarn feed wheel 4 with a reference numeral ver¬ ver¬. In addition, it is characterized by a black end gekenn¬. Furthermore, only the tube 24 is illustrated by the suture layer 21 in FIGS. 4 to 11.

In normal mode, the thread layer 21 rests. It stands in alignment with the thread inlet eye 48. The thread delivery wheel 4 rotates in the direction of the arrow 50 counterclockwise, for example. The thread 41 runs tangentially in a direction indicated by the arrow 52 yarn feeding direction of the yarn feed wheel 4 and via the yarn tension sensor 39 to a yarn consumption point. As can be seen in particular from FIG. 3, the thread circumscribes the thread delivery wheel 4 several times and is thus conveyed substantially free from slippage. However, slip-causing means, such as, for example, thread take-off pins or the like, may also be provided. Slippage can also be made possible by a slip clutch between the drive shaft 7 and the yarn delivery wheel or by a reduction of the looping of the yarn feed wheel 4 through the yarn 41. For example, slippage can be generated by laying only very few thread turns around the yarn feed wheel 4. It is also possible to thread in less than a whole To bring Utnschlingung with the yarn feed wheel 4 in contact (for example, a three-quarters wrap). The Steuerein¬ direction 11 determines the speed of the yarn feed wheel 4 and thus the yarn delivery speed and yarn delivery quantity. This mode is called positive mode (with tangentia thread run).

If the yarn requirement of the connected knitting machine stops, the yarn delivery wheel 4 stops. No more yarn is delivered. The normal operation according to FIG. 4 can be resumed at any time from a stop.

However, if the knitting machine or other machine starts to release thread 41, ie feed back, the yarn feeding device 1 assumes its return operation. The machine delivery device immediately detects a reduction in the thread tension on the thread support pin 42 and now attempts to restore the thread tension by reversing the drive device 3. It now performs a reverse rotation in the clockwise direction according to arrow 53 in FIG. 5. It thus takes up the thread 41 in the return direction according to arrow 54 with the yarn feed wheel 4 again. The yarn 41 runs tangentially onto the yarn feed wheel 4. In FIG. 5, the yarn feed wheel 4 has already rotated backwards by about 30 °. This can be seen by comparing the positions of the wire bow 14 in FIGS. 4 and 5. In order to maintain the yarn tension in front of the yarn feed wheel 4, the control device 11 has for this purpose actuated the yarn feeder 21 so that the tube 24, as shown in FIG. 5, has been adjusted by about 15 ° in the clockwise direction (arrow 51). Thus, the thread length present between the inlet eye 48 and the wire bow 14 in FIG. 5 now corresponds exactly to the sum of the thread length existing in FIG. see the inlet eye 48 and the wire bracket 14 plus the fed-back yarn length. The adjustment of the thread leveler

21 is preferably carried out not voltage-controlled but "positive", ie according to a calculated displacement determined from the detected reverse rotation of the yarn feed wheel No means are provided for detecting the yarn tension on the yarn feeder 21. If required, however, it is also a voltage-controlled actuation the Faden¬ legers 21 possible.

Upon further feeding back of the thread 41, the states of FIG. 6 to 9 occur. As shown in FIG. 6, the tube 24 of the yarn layer 21 lays the yarn 41 on the yarn storage surface 23. In return operation, the thread layer 21 runs much slower than the Fadenlieferrad 4. In Figure 6, the thread layer 21 has made about a quarter turn, while the wire bracket 14 and thus the yarn feed 4 have made more than half Umdre¬ hung.

Continued return delivery causes the Faden¬ casual 21, as Figure 7 shows, with further rotation of the Fadenlieferrads 4 gradually around the yarn storage surface 23 and this initially with a turn (Figure 8) and, if necessary, with other turns (Figure 9) be ¬ wraps. Due to the conicity of the yarn storage surface 23, the turns of the thread lie in the yarn store

22 next to each other and preferably not on top of each other. The speed ratio between the thread feeder 21 and the feed wheel 4 or the respective angles passed through are calculated to:

a _ T ₁ ^~ ß ^~ V ₂ where α is the angle traveled by the thread layer,

ß the angle traveled by the thread wheel,

T _{1 is} the diameter of the thread store and

r _{2 is} the diameter of the yarn feed wheel.

Thus, no thread is pulled through the thread inlet eyelet 48. In addition, the thread brake 49 can be braked to prevent the thread from drawing.

If the knitting machine stops delivering thread, the return operation is terminated. This can happen, for example, in the position of the thread feeder 21 and the yarn feed wheel 4 illustrated in FIG. When the knitting machine starts to take off thread, the yarn feeding device changes to a modified normal operating mode, in which thread is no longer tension-controlled, but again controlled by volume, i. 4 speed is supplied to the knitting machine under speed presetting for the Faden¬ delivery wheel. The direction of the arrows in FIGS. 9 to 5 is reversed. Now run the thread layer 21 and the Fadenliefer¬ wheel 4 counterclockwise with the above angular or speed ratio, whereby the thread layer 21 decreases the thread from the yarn storage surface 23 and the yarn feed 4 on its inlet side 19 zuleitet. In turn, no thread is drawn through the thread inlet 48. This modified mode of operation continues until the thread store 22 is empty, i. until the tube 24 has assumed the position illustrated in FIG. 4 in the vicinity of the thread entry eye 48.

When this point is reached, the thread-laying 21 stops, wherein the yarn feed wheel 4 continues to rotate unchanged. Only now is normal normal operation achieved. While only the yarn wound on the yarn storage surface 23 has been taken up again in the modified normal operation and has been fed to the yarn feed wheel and thus to the knitting machine, yarn is now pulled against the action of the yarn brake 49. The return operation and the modified normal operation can alternate as often as desired. Neither during the return operation nor during the modified normal operation is yarn pulled from the yarn package through the yarn brake 49.

While in the above description it has been assumed that the thread-laying drive device 27 operates precisely in a position-controlled manner, it should be noted that this does not necessarily have to be so configured. It is also possible to use a non-position-controlled electric motor 28 while only monitoring the position of one of the two gears 31, 32. In the simplest case, it may be sufficient to provide only one or more marks on the toothed wheel 32 or the toothed wheel 31, for example in the form of optical marks (holes) or magnets, which are then replaced by optical sensors or magnetic sensors (FIGS. Hall sensors) are detected. When the yarn feed wheel 4 rotates backwards, the yarn feed position or rotation is detected and the motor 28 for moving the yarn feeder 21 is actuated. The motor 28 can be supplied with a controlled current wer¬ to generate a predetermined torque. This should be less than that for tightening thread through the thread brake 49th required torque. In this way, the yarn store 22 only picks up the yarn delivered by the yarn delivery wheel 4. Turns the yarn feed wheel 4 its direction of rotation to the thread store 22 again empty, it works against the low tension of Fadenle¬ gers 21. This can also be reduced in this case by the current of the motor 28 is reduced. Reaches the suture 21 his example, by the Hall sensor and the magnet on the gear 31 (or 32) marked position (fixed position), the sizer 21 is braked, ie locked in fixed position and the yarn feed 4 fetches overcoming the yarn brake 49 fresh thread from the Garnspule after.

Notwithstanding the above description, it should be pointed out that the modified normal operation with consumption of the storage reserve as well as the normal operation with yarn recovery from the upstream coil can be carried out in a voltage-controlled manner under the control of the yarn tension sensor 39.

A modified embodiment of the Fadenlieferge¬ apparatus 1 schematically illustrates Figure 10. The modification consists in the formation of the yarn storage surface 23, which is divided here into individual surfaces 55, 55. These are formed by individual pins 57, 58, which are arranged as a wreath in the vicinity of the yarn feed wheel 4. Otherwise the previous description applies.

The yarn feeding device 1 allows a particularly fast starting and stopping of thread deliveries. For this purpose, it can assume a dynamic mode, which is illustrated below with reference to FIG. The dynamic mode of operation is based on the assumption that, prior to the start of delivery, a smaller reserve of thread is built up in the case memory 22, for example, as FIG. 11 illustrates. The thread reserve can also be lower. It may have been constructed by the yarn layer 21 in the standing delivery wheel 4 in the illustrated position, that is, for example, has been rotated by a few degrees in the clockwise direction. In this case, thread 41 is dragged through the thread inlet eyelet 48 and over the thread storage surface 23. This can happen preventively whenever the yarn feeding wheel 4 stops out of normal operation. It can also happen 'controlled by the pattern memory of the knitting machine only when a high-dynamic start, ie a sudden increase in the thread requirement is expected.

FIG. 11 illustrates the yarn feeding device in a state prepared for the highly dynamic starting. If the start signal for the yarn feeding device 1 now comes from the knitting machine, the yarn feeder 21 and the yarn delivery wheel 4 are simultaneously accelerated counterclockwise (arrows 50, 51a). As a result of the acceleration of the delivery boom, the yarn delivery wheel 4 is temporarily freed temporarily, ie for its run-up phase, from the load of the yarn otherwise being towed by it to the yarn package. For the startup phase, the yarn feed wheel 4 has thus overcome only its own and the inertia of the yarn winding carried by him. If, for example, it reaches its maximum speed after a half or three-quarter revolution, the yarn delivery arm 21 arrives at its fixed position below the yarn inlet eyelet 48 and stops there gradually, ie gently, to a standstill. This avoids Betriebs¬ art yarn tension peaks between the Fadenlie¬ _ferrad, 4 and of the knitting machine during sudden Fadenbe¬ allowed.

A yarn feeding device 1 has a yarn feed wheel 4 with a drive device 3 and a yarn store 22 with a yarn feeder 21, which has its own yarn feeder drive device 27. A control device 11 controls both drive means 3, 27 in such a way that, on the one hand, a purely positive operation of the yarn delivery wheel 4 and, on the other hand, a return of yarn during oscillation of the knitting machine is made possible. In addition, the dynamics of a yarn feeding device 1 can be improved with this configuration.

LIST OF REFERENCE NUMBERS

1 thread feeding device

2 carriers

3 drive device

4 thread feed wheel

5 electric motor

6 anchors

7 output shaft

8 angle encoder

9 circuit

11 control device

12 stator winding

13, 14, 15 wire hanger

16 hub

17 section

18 lead

19 inlet side

21 thread layers

22 thread storage

23 yarn feeding surface

24 tubes

25 lift lever

26 bearings

27 thread-laying drive device

28 electric motor

29 output shaft

31, 32 gears

33, 35 signal lines

34, 36 control lines

37 locking device

38 E1ektromagnet

38a stop pin

39 Thread tension sensor thread

Thread support pin

Force measuring device

Enclosures

Display, 47 operating elements

yarn inlet eyelet

Thread brake, 56 individual surfaces, 58 pens

Thread delivery direction (arrow)

Return direction (arrow) a, 50 Forward rotation (arrow), 53 Backward rotation (arrow)

Claims

claims:

1. Yarn feeding device (1), in particular for thread-returning knitting machines,

with a yarn feed wheel (4) which has an inlet side (19) and a storage section (17) for receiving a yarn package,

with a drive device (3), which is connected to the Faden¬ delivery wheel (4) and operable in two opposite directions of rotation to deliver in normal operation with forward rotation (50) thread (41) in the yarn feeding direction (52) to a yarn consumption point and in Return operation with reverse rotation (53) from the yarn consumption point in the return direction (54) zurück¬ given thread (41) rewind on the yarn feed wheel (4),

with a yarn store (22), which is arranged in relation to the yarn feed direction (52) in front of the yarn feed wheel (4), in order to return it from the feed wheel (4) at its yarn inlet side (19) during reverse rotation (53) To temporarily store thread (41).

2. Yarn feeding device according to claim 1, characterized gekennzeich¬ net, that the yarn store (22) between a Faden¬ brake (49) and the yarn feed wheel (4) is arranged.

3. Yarn feeding device according to claim 1, characterized gekennzeich¬ net, that die.Fadenbremse (49) is a controlled Faden¬ brake whose braking force is switchable by an electrical control signal at least between two values bar.

4. Yarn feeding device according to claim 1, characterized gekennzeich¬ net, that the yarn store (22) has a to the Fadenlie¬ ferrad (4) concentric yarn storage surface (23) auf¬.

5. Yarn feeding device according to claim 1, characterized gekennzeich¬ net, that the yarn storage surface (23) is formed contiguous.

6. Yarn feeding device according to claim 1, characterized gekennzeich¬ net, that the yarn storage surface (23) Chen in Einzelflä¬ (55, 56) is divided.

7. Yarn feeding device according to claim 1, characterized gekennzeich¬ net, that the thread store (22) is assigned a thread layer (23).

8. Yarn feeding device according to claim 1, characterized gekennzeich¬ net, that the thread-laying (23) a yarn guide eyelet

(24), which is guided on a to the yarn feed wheel (4) concentric circular path.

9. Yarn feeding device according to claim 1, characterized gekennzeich¬ net, that the suture layer (23) is assigned a thread-An¬ drive means (27).

10. Yarn feeding device according to claim 1 and 9, characterized ge indicates that the drive means (3) and the thread-laying drive means (27) by a Steuer¬ device (11) are controlled, the following Steuer¬ schema realized:

a) in normal operation without previous return operation if it leaves the thread-laying device (23) in a fixed position and the drive device (3) runs with forward rotation (50),

b) in the return mode, it drives the drive device (3) with reverse rotation (53) and the thread feeder (23) in the same reverse direction at reduced speed,

c) during normal operation with previous return operation, it allows the drive device (3) with Vor¬ wärtsdrehung (50) and the Fadenleger-Antriebsein¬ direction (27) also with forward rotation je¬ doch run at a reduced speed until it covered the distance a) has passed through and / or reached its fixed position.

11. Yarn feeding device according to claim 10, characterized gekenn¬ characterized in that the yarn feeder (23) and the Fadenlie¬ ferrad (4) run both in forward rotation and in reverse rotation each in a fixed Dreh¬ number ratio.

12. Yarn feeding device according to claim 11, characterized gekenn¬ characterized in that the speed ratio is set so that in the return operation of the Fadenliefer¬ rad on its yarn inlet side (19) to the Fadenspei¬ cher (22) discharged thread length equal to the Fa¬ Memory (22) stored thread length is.

13. Yarn feeding device according to claim 1, characterized gekennzeich¬ net, that the drive means (3) is an electric motor

(5).

14. Yarn feeding device according to claim 13, characterized gekenn¬ characterized in that the drive device (3) has a posi¬ tion-controlled electric motor (5).

15. Yarn feeding device according to claim 9, characterized gekennzeich¬ net, that the thread-laying drive means (27) is an electric motor (28).

16. Yarn feeding device according to claim 15, characterized gekenn¬ characterized in that the electric motor (28) is a position¬ regulated electric motor.

17. Yarn feeding device according to claim 1, characterized gekennzeich¬ net, that between the Fadenlieferrad (4) and the Fa¬ denverbrauchsstelle a yarn tension sensor (39) is arranged an¬.

18. Yarn feeding device according to claim 1, characterized gekennzeich¬ net, that the drive device (3) is operated in a Posi¬ tivlieferbetriebsart at least during normal operation at a predetermined speed.

19. Yarn feeding device according to claim 18, characterized gekenn¬ characterized in that the predetermined speed is predetermined proportional to a knitting machine speed.

20. Yarn feeding device (1), in particular for thread-returning knitting machines,

with a yarn delivery wheel (4) which has a yarn inlet side (19) and a storage section (17) for receiving a yarn package,

with a drive device (3) connected to the thread and in two opposite directions of rotation to operate in normal operation with forward rotation (50) thread (41) in the yarn feeding direction (52) to a yarn consumption point and in return operation with reverse rotation (53) of the yarn consumption point in the return direction (54) rewinding yarn back onto the yarn feed wheel (4),

with a yarn tension sensor (39) which is arranged between the yarn feed wheel (4) and the yarn consumption point,

with a control device (11) which drives the drive device in normal operation in positive operation and in return operation in yarn tension control operation.

21. Yarn feeding device according to claim 20, characterized gekenn¬ characterized in that the rotational speed of the drive means (3) in positive operation at least within predetermined

Limits of the thread tension coincides with a given Dreh¬ number.

22. Yarn feeding device according to claim 20, characterized gekenn¬ characterized in that the rotational speed of the drive device (3) in return operation of the control device (11) based on the yarn tension is set so that the yarn tension remains as constant as possible during the return operation.

23. Yarn feeding device according to claim 1 or 20, characterized ge indicates that between the yarn feed wheel (4) and the yarn consumption point a dynamic yarn storage is intended rather.

24, yarn feeding device according to claim 1 or 20, characterized ge indicates that the yarn store (22), its An¬ drive (28), the yarn feed wheel (4) and its drive (5) are carried by a .Megeneric carrier.

25. Yarn feeding device according to claim 24, characterized gekenn¬ characterized in that the drive (28) of the yarn store (22) and the drive (5) of the yarn feed wheel (4) are housed in a common housing.

26. Yarn feeding device according to claim 1, characterized gekennzeich¬ net, that in the housing a control device (11) for the drives (5, 28) is housed.

27. Yarn feeding device according to claim 1 or 20, characterized ge indicates that the yarn store (22) has a Um¬ running lever (25) which carries at its free outer end a thread guide means (24) and its pivot axis or rotation coaxial with the Rotary axis of the yarn feed wheel (4) is arranged.

28. Yarn feeding device according to claim 1 or 20, characterized ge indicates that between the drive means (3) and the thread (41) a slip-promoting Einrich¬ device is provided.

29. Method for operating a yarn feeding device (1)

with a yarn delivery wheel (4) which has a yarn inlet side (19) and a storage section (17) for receiving a yarn package, with a drive device (3), which is connected to the Faden¬ delivery wheel (4) and operable in two opposite directions of rotation to deliver in normal operation with forward rotation (50) thread (41) in the yarn feeding direction (52) to a yarn consumption point and in Return operation with reverse rotation (53) from the yarn consumption point in the return direction (54) zurück¬ given thread auf¬ on the yarn feed wheel (4) auf¬,

with a yarn tension sensor (39) which is arranged between the yarn feed wheel (4) and the thread consumption parts,

wherein the drive device (3) is operated in positive operation in normal operation and in yarn tension control operation in return operation.