EP1156143B1 - Method for oparating a creel and creel for a winding machine - Google Patents

Abstract

At least one out of a group of threads of the same running length (L1 or L2) is monitored continuously for thread tension, between leaving the creel frame and winding on the winding machine. Measured- and desired values are compared. When a departure is detected, thread brakes of the relevant group are adjusted, causing the actual value to approach the desired value. An Independent claim is included for the corresponding creel frame for a winding plant. Preferred features: Thread brakes (18) of each thread group having the same running length, are controlled by a common- or an individual drive motor (20). For each thread group having the same running length, actual thread tensions are measured on two or more threads, to determine a mean for comparison with the desired value. A further variant of the method based on the foregoing principles is described. Thread brakes of a vertical row of spooling locations are adjusted by a common drive motor. Further variants of the plant, based on the foregoing principles, are also claimed.

Description

The invention relates to a method for operating a creel for a winding system according to the preamble of claim 1. With such a method is as optimal as possible Tension compensation of all threads on a creel, because the different lengths of the threads between Spooling and winding machine and the related Thread guide without appropriate compensation to different Thread tensions would lead. The result would be one uneven winding density.

By EP-A 319 477 is a device for voltage compensation the threads become known at a creel, at which via a common control rod, the thread brakes of vertical rows of winding units acted upon differently strong are. The control rod is activated by drive motors, which receive control signals from a processor. Measured is thereby the actual value of the thread tension of a whole thread group by means of a measuring roller just before winding. A consideration of the thread tension of individual threads or individual groups of threads is not possible.

DE-A 195 46 473 discloses a method for controlling Winding devices for yarn sheets. Again, there is a Tension measurement of the thread bandage just before winding to by means not shown in detail on the tension of the threads to interact with the creel. With the help of a cross over the thread bandage However, the mobile measuring cart is the successive one Tension measurement of monofilaments in a predetermined Time interval possible. From this, a mean voltage value is formed, Accordingly, the common tensioning of all threads takes place. With this procedure, an individual regulation of Individual threads or individual groups of threads practically hardly realized because not every thread is scanned at the same time can be. Other disadvantages of this procedure are that the Intermittent measurement at today winding speeds too slow and also the measured thread is mechanically acted upon by the measuring means, which is an individual Thread tension change causes.

DE-A 44 18 729 also relates to a device for controlling the thread tension at a creel. This device has for each bobbin holder directly at the winding unit one Brake rotor on. Serves as a sensor for the thread tension a tensioning lever, which acts through the unwound thread becomes. At each bobbin holder engages a fluid pressure working Loading device on the clamping lever, wherein the fluid pressure is adjustable for all load devices together. The Individual control of the thread tension can thus by a general adjustment of all thread tensioner are superimposed. However, a disadvantage of this device is that the control loop is limited directly to the winding unit. This arrangement is not suitable for a creel with Overhead deduction. The deceleration is directly on the bobbin holder also not suitable for all work processes and the different ones Running length of the threads between winding unit and winding machine remains unconsidered.

Finally, DE-U-296 08 169 discloses a winding device for threads of bobbin creels in which a measuring device For determining yarn tension is arranged in threads, the Central adjustment of the winding units associated Vorumschlingungsstangen is controllable according to the measurement result. The Measuring device consists of individual pressure measuring strips, respectively Support a variety of threads. This is a surveillance the tension in the monofilament also not possible, apart from the fact that the Druckmessleisten only the can act on the outermost threads of a thread bandage.

It is therefore an object of the invention to provide a method of the initially to create the kind mentioned, with simple means a optimal and versatile control of the entire Wikkelprozesses allowed. It should be at low energy consumption Modern electronic means can be used. The gate control should address as many different operating conditions as possible be customizable. This object is according to the invention a method having the features in claim 1.

By the continuous measurement of the actual value of the thread tension at least one thread from each thread group with the same run length is the tension behavior of the threads on the entire gate detectable with minimum time delay. The measurement takes place in the area between leaving the gate and winding up on the winding machine, which ensures that takes into account the different run lengths and deflections of the threads become. The rule process can be used for the groups of Threads are designed individually, making the gate versatile can be used. The mechanical function and arrangement of the thread brakes plays only a minor role. By this process becomes thread influences, like different thread thicknesses, Thread structure, other material influences and influences balanced at the withdrawal point in the creel.

Particularly advantageous can be with the inventive method each individual thread brake with a drive motor associated with it activate. This is affordable with the today offered miniaturized drives readily possible.

However, it is also possible with the method according to the invention the thread brakes of each thread group with the same run length with to activate a drive motor. As a rule, the threads form of vertical rows (rails) of winding units per gate side one thread group with the same run length. It is therefore in a known manner possible, all thread brakes on one vertical row (rail) with a common transmission link too activate, with the drive motor in the area of the top or the lowest winding unit is arranged. Thus it is also possible for a desired thread group a group-wise control each with a drive motor perform.

In certain cases, it is sufficient if from each thread group with Same run length of at least two threads of the actual value of the thread tension is measured, and if out of the at least two actual values an actual mean is formed, which is the target value is compared. This measuring principle is based on the assumption that the threads of a certain thread group are about the same behavior. However, despite the selective measurement is an admission the thread brakes both by means of individual drive motors on each yarn brake, as well as by means of a common Drive motor possible.

Further procedural advantages can be achieved if the threads in the thread running direction before each thread brake at least a biasing device with an additional braking force which are fixed as the basic value is set or which depends on the measured actual value becomes.

Depending on material properties, such as texture, rotation, Strength and Krangelneigung, etc. of the threads, must be different Biasing devices are used to ensure trouble-free To ensure drainage of threads. The pretensioner devices on a loop basis, such as eyelet pretensioners, Crepe pretensioners, etc. can be used individually or by rail with one Drive motor can be adjusted to ensure optimum thread flow to obtain.

Moreover, it is possible to use the different run lengths of the Threads or thread groups (gate length compensation) exclusively to compensate with the help of the biasing devices. On This way, the following thread brakes are mandatory of this necessary compensation and they can respect develop their braking power to full efficiency.

In addition, the above-mentioned biasing means can also be used to increase the thread tension before entering the thread brakes, wherein the thread tension is also controlled individually or in groups together with the thread brake.
But these biasing devices can also be used as the only means for voltage distribution. No additional thread brakes would be required, which is very cost-effective. The term "thread brake" as used herein thus broadly encompasses all pretensioners.

In certain cases, it is advantageous if at the winding machine the tensile force of united to a thread band entity the threads in the area in front of the winding emergence point as a strip tension actual value measured and compared with a strip tension target value and when detecting any deviation all the thread brakes be adjusted simultaneously such that the strip tension actual value approximates the strip tension target value. This additional scheme of the strip tension superimposed on the above-described control of the thread tension, where also all voltage changes between taken into account the thread tension sensors and the winding run-off point become.

The invention also relates to a creel for a winding system, that in device-wise by the features in the Claim 7 is characterized. In such a creel For example, the thread tension on at least one thread of each thread group measured with the same run length by means of thread tension sensors become.

However, it is also conceivable to use at least two yarn tension sensors for the measurement at least two threads from each Group of threads of equal length, to obtain an average value to build.

Advantageously, the measurement is carried out on threads that are not of deducted adjacent winding units of the corresponding rail become.

There are basically different principles of yarn tension sensors known. As particularly advantageous for the inventive Purpose, however, sensors have proven that a Force measuring device with a responsive strain on measuring element have, wherein the force occurring across the thread is measurable on the deflected thread. Such a thread tension sensor is described for example in DE-A 197 16 134, the contents of which are hereby incorporated in their entirety. Of the Sensor is compact and relatively compact at low external dimensions insensitive to contamination. The piezoresitiv working Measuring bridge requires very little energy, which may be the case large number of sensors a significant role plays. The measurement is also directly linear with the Movement of the probe, bringing the possibility of measurement errors is reduced.

The thread tension sensor can be functionally also on special easy way as a thread monitor for threadline or thread breakage control of the thread. Under or over the thread tension of one or more threads the lower or upper control range, a warning signal is issued or the Winding machine can be stopped automatically.

The described functions of the thread tension sensor can in addition to the use for the thread tension control only as Monitoring function in a winding system for the entire yarn sheet be used.

Be particularly advantageous as a drive motor for the thread brakes (Normal-pressure yarn brake, for example, disk brake, belt-thread brake, dynamic Thread brake, etc.) or mentioned Biasing devices (eyelet pretensioners, crepe pretensioners) Stepper motors used, which have a self-locking Gear acting on the brake fluid. The advantage of this Stepper motors is that they only during activation, but not in the hold phase to absorb energy. In order to the energy consumption can be lowered considerably. On self-locking drive motor, for example with a worm gear or a self-locking spindle drive ensures holding a position approached by the stepper motor becomes. The advantage of the stepper motor lies in the fact that at any time the position of the thread brakes or the position of the biasing means are known and can be calibrated.

Each winding unit can have at least one signal component, in particular a thread monitor for threadline or thread breakage control of the thread and / or an optical signaling means for identifying assigned to the winding units or as a plug-in his. The thread monitoring can be done by various known per se Principles of operation, such as the mechanical Falling needle principle, Hall sensors, optical monitoring means etc. A signaling device to facilitate the assembly of a Bobbin creel has become known, for example, by EP-A-329 614.

All electrically activatable means associated with a winding unit, in particular the drive motors for the thread brakes, but Also, the mentioned signal components can be connected via common signal lines to be activated. For this purpose they stand over serial interfaces with a central control device in Operatively connected. This obviously eliminates a costly Wiring of the individual components.

Fig. 1

eine stark schematisierte Seitenansicht auf ein Spulengatter mit den Merkmalen der Erfindung,

Fig. 2

eine Draufsicht auf das Spulengatter gemäss Fig. 1,

Fig. 3

eine Draufsicht auf eine einzelne Spulstelle mit Vorspannereinrichtungen und mit einer Tellerbremse,

Fig. 4

eine perspektivische Darstellung eines Stützprofils mit darin angeordneten Tellerbremsen, in Gesamtansicht und im Detail,

Fig. 5

eine schematische Seitenansicht einer Spulstelle mit einem Ösenvorspanner, einem Crepevorspanner und mit einer Tellerbremse,

Fig. 6

eine schematische Seitenansicht einer Spulstelle mit einem Ösenvorspanner und mit einer Umschlingungsfadenbremse,

Fig. 7

eine Prinzipdarstellung eines Spulengatters mit fadenweiser Spannungsmessung, einzeln angetriebenen Tellerbremsen und einzeln angetriebenen Ösenvorspannern und Crepevorspannern,

Fig. 8

eine Prinzipdarstellung eines Spulengatters mit fadenweiser Spannungsmessung, einzeln angetriebenen Tellerbremsen und schienenweise angetriebenen Ösenvorspannern und Crepevorspannern,

Fig. 9

eine Prinzipdarstellung eines Spulengatters mit schienenweiser Spannungsmessung, schienenweise angetriebenen Tellerbremsen und schienenweise angetriebenen Ösenvorspannern und Crepevorspannern, und einem Fadenwächter zwischen Spule und Fadenbremse,

Fig. 10

eine Prinzipdarstellung eines Spulengatters mit fadenweiser Spannungsmessung, einzeln angetriebenen Umschlingungsfadenbremsen und einzeln angetriebenen Ösenvorspannern.

Fig. 11

eine Prinzipdarstellung eines Spulengatters mit fadenweiser Spannungsmessung, einzeln angetriebenen Umschlingungsfadenbremsen und schienenweise angetriebenen Ösenvorspannern,

Fig. 12

eine Prinzipdarstellung eines Spulengatters mit schienenweiser Spannungsmessung, schienenweise angetriebenen Umschlingungsfadenbremsen und schienenweise angetriebenen Ösenvorspannern, und einem Fadenwächter zwischen Spule und Fadenbremse, und

Fig. 13

eine perspektivische Darstellung von Gruppen von Fadenspannungssensoren auf verschiedenen Ebenen.

Further advantages and individual features of the invention will become apparent from the following description of exemplary embodiments and from the drawings. Show it:

Fig. 1

a highly schematic side view of a creel with the features of the invention,

Fig. 2

a top view of the creel according to FIG. 1,

Fig. 3

a plan view of a single winding unit with biasing means and with a disk brake,

Fig. 4

a perspective view of a support profile with plate brakes arranged therein, in general view and in detail,

Fig. 5

a schematic side view of a winding unit with a Ösenvorspanner, a Crepevorspanner and with a disk brake,

Fig. 6

a schematic side view of a winding unit with a Ösenvorspanner and with a belt thread brake,

Fig. 7

a schematic diagram of a creel with thread-wise tension measurement, individually driven plate brakes and individually driven Ösenvorspannern and Crepe prestressers,

Fig. 8

a schematic diagram of a creel with thread-wise tension measurement, individually driven plate brakes and rail-driven Ösenvorspannern and Crepe prestressers,

Fig. 9

a schematic diagram of a creel with rail-wise voltage measurement, rail-driven plate brakes and rail-driven Ösenvorspannern and Crepe prestressers, and a thread monitor between coil and yarn brake,

Fig. 10

a schematic diagram of a creel with thread-wise tension measurement, individually driven Umschlingungsbrarnen and individually driven Ösenvorspannern.

Fig. 11

a schematic diagram of a creel with thread-wise tension measurement, individually driven Umschlingungsfadenbremsen and rail-driven Ösenvorspannern,

Fig. 12

a schematic diagram of a creel with rail-wise voltage measurement, rail-driven belt thread brakes and rail-driven Ösenvorspannern, and a thread monitor between the coil and yarn brake, and

Fig. 13

a perspective view of groups of yarn tension sensors at different levels.

According to Figures 1 and 2, there is a winding system 1, for example a wastewater treatment plant, a creel 2 and a Winding machine (cone sharpening, warping, building machine, etc.) 3. The individual thread bobbins 4 are at winding stations 7 of the creel plugged and the jointly withdrawn threads 5 pass at least one thread brake 6 each to maintain a predetermined Thread tension.

The example shows a parallel gate with a left gate side LS and with a right-hand side RS. The coils form thereby vertical and horizontal rows, whereby evidently one vertical row on each side of the gate, one thread group forms, the yarn running length of the winding unit to the winding machine is the same size. But the same principle can be used with any other type of gate, e.g. in a V-gate, used become.

At the gate, regardless of the thread running length at different Make coils of different genus, for example different yarn qualities or different Thread colors are plugged.

Fig. 2 shows the two thread groups with the longest run length L1 and the two thread groups with the shortest run length L2.

In the area of the gate side 8, which of the winding machine 3 am Next, the thread tension sensors 9 are preferably for at least one thread from the thread group with the same Run length (per rail) arranged. The arrangement of the thread tension sensors however, this is not mandatory. in principle It would be beneficial if the thread tension sensors were so close as possible to the winding point of the winding machine introduce.

The thread tension sensors can therefore also in an area before the winding point of the winding machine i. between reading 10 and warp sheet 11 arranged to merge the threads. With appropriate miniaturization of the thread tension sensors they can thus be arranged so close together, that, despite the fact that the threads have already been brought together, individual thread can be acted upon. That would even work the previous bandzugregulierung unnecessary, because all changes the braking force until just before the winding formation can be measured.

This could also be the thread line between the creel and the winding machine are included in the control loop. This Alternatively, it is also possible that the known per se Band tension regulation with a common tension measurement the whole thread bandage just before winding maintained becomes, so that according to the invention individual rails or group-wise control process still by a global control process is superimposed. Such a band tension regulation is For example, by CH-A-675 598 become known, the disclosure hereby accepted in full.

After leaving the creel, the threads get into the Area of the winding machine 3, where they first a Geeseblatt 10th happen in which the threads get their correct order. Subsequently, the threads are fed to the warper blade 11, in which they are brought together to then as a thread bandage 12 via a deflection and / or measuring roller 13 on the Wikkel 15 or wound on the winding tree 14.

Depending on the purpose of the creel can be at a winding unit 7 different brake means may be arranged.

Fig. 3 shows, for example, how a abgegewikkelter of a coil 4 Thread 5 two wrap-around biasing devices and passes through a thread brake. An eyelet pretensioner 16 and a crepe pretensioner (named after the swirled Crepe yarn) 17 have the task in addition to the prestressing, to raise the crane-angel formed by the thread and as chicane to counteract spinback and thus avoid Krangelbildung. At the same time they cause a limitation of the thread balloon, which forms when unwinding from the coil 4.

The wrap of the biasing means 16 and 17 can railways or individually adjusted, e.g. by a Rotary or pivoting movement. The main braking force is by a Plate brake 18 with two arranged in the direction of thread travel one behind the other Brake actuator units applied. The plate brake is housed in a U-shaped vertical support profile 19, in the U-leg thread guide eyelets for the passage of the thread 5 are arranged.

It may also be advantageous if the crepe pretensioners are individual per thread are adjustable to crane gel formation at different To avoid yarn types and thus a good flow behavior of the thread.

Fig. 4 shows further details of such a disk brake. About each plate brake 18 is directly in the support section 19 a individual drive motor 20 attached. This presses over an adjustment support 22 a pressure element 23, which the brake plates burdened or relieved.

Figures 5 and 6 show a schematic representation of winding units with different pretensioner and brake devices. According to FIG. 5, the thread 5, as shown in FIG. 3, first passes through a Ösenvorspanner 16 and then a Crepevorspanner 17, before being guided by the disk brake 18.

Fig. 6 shows an alternative embodiment of a winding unit with a wrap thread brake 39. As a pretensioner device only one eyelet pretensioner 16 is used. With the wrap thread brake can the twist angle and thus the Degree of wrap are set. This will be the Friction conditions and thus set the thread tension or regulated. The pretensioner and brake devices according to FIGS. 5 and 6 can be both rail-wise and individually be adjusted by thread.

The schematic diagram according to FIG. 7 shows one, in each case on the winding machine 3, distant coil row 24 and a close Coil row 25 with three levels each, so with three winding units each. In fact, each vertical row (rail) can reach up to 12 Have floors. The thread tension is for all vertical Rows (rails) measured on a common measuring plane 38.

As shown, each thread has its own thread tension sensor 9th

These thread tension sensors can be used for the control of the thread tension, for monitoring the specified yarn tension range and used as thread breakage monitoring.

Between the spool and the disk brake the thread goes through one Eyelet pretensioner 16 and then a crepe pretensioner 17. These pretensioners will each have one individual drive motor 20 driven. After the pretensioner device the threads arrive at a disk brake 18, which also individually provided with a drive motor 20 is. On the plate brakes of a rail but can also be common drive motor 40 are activated, so that the lower Brake plate in a known manner to turn to cuts to avoid the threads in the brake plates. It is also very advantageous when the drive motor 40 for the plate drive is controllable such that it on vertical rows (Rails) of winding units without threads based on Daseinskontrolle by the thread tension sensors or the thread monitor automatically can be disabled. Through the thread tension sensors or by the thread monitor is always known which winding units are not equipped.

In addition, each winding unit is still an optical signal element 26 and an acknowledgment switch assigned as a Spulenaufsteckhilfe serves, and thus the placement of the creel facilitated. The signal element serves the various Coil character or coil types according to the prescribed Record report without errors.

Each vertical row (rail) is connected to an electronic node 29, 29 'provided, which via a serial line system 28 different signals can handle. Every gate side has its own main processor 30, 30 ', whose Activities via a delivery processor 31 coordinated become. This can also regulate a gate side individually. The thread tension setpoints can be displayed on a display by rail be entered. The entered nominal values are replaced by the transmission processor to the main processors 30 and 30 ' forwarded and compared there with the actual values. The actual values for the thread tension are from the thread tension sensors measured on a common measurement plane 38 and to the measurement collection units 32 and from there to the main processors 30 and 30 'forwarded. These main processors thus take over the Function of a comparator for comparing the ACTUAL values with the entered nominal values.

The embodiment according to FIG. 8 differs from FIG the one according to FIG. 7 in that the eyelet pretensioners 16 and the Crepevorspanner 17 rails with a common Drive motor 21 are adjustable. The plate brakes have 18 however also via individual drive motors 20.

In the embodiment of FIG. 9, however, comes another Measuring principle for use. As shown, not everyone has Thread via its own thread tension sensor. Per thread group L1 and L2, each with the same run length, are only two thread tension sensors each 9 and 9 'provided. It would also be conceivable per thread group more than two thread tension sensors or even to arrange only a single yarn tension sensor. At two or more thread tension sensors each form an average, which is representative of all threads of the same group is and the main processors 30, 30 'is supplied.

At each vertical row of coils is in the direction of yarn directly after the thread bobbins 4, a thread monitor 27 for the existence control arranged. This is in the present embodiment necessary, because not all threads the thread tension sensors 9 take over this task. The threadguards could but also arranged between the coil and the gate output become.

As in the embodiment of FIG. 8, the Ösenvorspanner 16 and the Crepevorspanner 17 rail over common drive motors 21 adjusted. But also the drive the plate brakes 18 is not individual, but railways via a common drive motor 21.

In the embodiment according to FIG. 10, in turn, every single one is Thread provided with its own yarn tension sensor 9. Instead of plate brakes, as in the previous embodiments, However, wrap thread brakes 39 are used Insert, which individually with an individual drive motor 20 are adjustable. As a biasing device serve exclusively Eyelet 16, which also have individual drive motors 20 are adjustable.

The embodiment of FIG. 11 differs according to the one shown in FIG. 10 only in that all Ösenvorspanner 16 a vertical row (rail) with a common Drive motor 21 are adjustable.

Finally, the embodiment according to FIG. 12 again shows a measuring principle, in which analogous to the embodiment 9, the thread tensions of a thread group of only ever two values are averaged. Wrap around brakes are used here 39, but not one, but one common drive motor 21 are adjustable. Also the adjustment eyelet pretensioner 16 is rail-mounted. For the Daseinskontrolle the threads are also as in Figure 9 additional Thread monitor 27 is used.

Evidently, according to the invention, other combinations would also be possible conceivable, e.g. through the use of alternative thread brakes or biasing devices or by omitting or adding other measuring, control or signaling devices at the individual winding units.

In Fig. 13 is shown as for each floor on the gate a Whole thread tension sensor battery 34, consisting of the thread tension sensors 9, is arranged. The attachment takes place on a common support 33. Each sensor has a movable sensor 37, which in such a way between two yarn guides 36 is arranged, that the thread 5 is deflected. The actual measuring bridge is arranged in a closed housing 35, the individual housings immediately next to each other can be attached.

The summary of the thread tension sensors in 8-units has the advantage that these units are mechanically inexpensive, Space-saving and electrically compatible with an 8-bit unit are.

Claims (24)

1. Method for operating a bobbin creel (2) for a winding machine (1), more particularly a warping machine, having a plurality of bobbin locations (7), wherein a winding machine (3) is used to jointly draw off a plurality of threads (5) from the bobbin locations, the thread being acted on by a braking force at not less than one thread tension device (6) at each bobbin location in dependence on the distance to be travelled (L) between the bobbin location and the winding machine, and a plurality of threads with the same distance to travel forming at least one thread group, characterised in that
   the actual thread tension value is continuously measured on at least one thread from each thread group with the same distance to travel, in the zone between leaving the creel and being wound onto the winding machine,
   the measured actual value is compared to a nominal value,
   and, if the actual value is found to deviate from the nominal value, the thread tension devices of the group of threads concerned are adjusted in such a manner that the actual value approximates to the nominal value, the measurement of thread tension always being performed on individual threads.
2. Method according to claim 1, characterised in that the thread tension devices of each thread group having the same distance to travel are activated by a common drive motor (21).
3. Method according to claim 1, characterised in that the thread tension devices of each thread group with the same distance to travel are activated by a drive motor (20) operatively associated with each thread tension device.
4. Method according to any of claims 1 to 3, characterised in that the actual thread tension value is measured on not less than two threads from each thread group having the same distance to travel, and that from the not less than two actual values a mean actual value is constituted which is compared to the nominal value.
5. Method according to any of claims 1 to 4, characterised in that at not less than one pre-tensioning device (16, 17) in the direction of thread travel the threads are acted upon by an additional braking force which is fixed in dependence on the actual value measured, or which is permanently fixed as the default value.
6. Method according to any of claims 1 to 5, characterised in that on the winding machine the tensile strength of the entirety of the threads combined into a ribbon is measured as an actual ribbon tension value in a zone ahead of the coiling point and compared to a nominal ribbon tension value, and that if a deviation is found all the thread tension devices are simultaneously adjusted in such a manner that the actual ribbon tension value approximates to the nominal ribbon tension value.
7. Bobbin creel (2) for a winding machine (1), more particularly a warping machine, having a plurality of bobbin locations (7) from which a plurality of threads can be drawn simultaneously by a winding machine (3), and having at least one thread tension device (6) operatively associated with each bobbin location, at which brake the thread can be acted upon by a braking force in dependence upon the distance to be travelled between the bobbin location and the winding machine, the threads with the same distance to travel constituting at least one thread group, characterised in that
   in the zone between the bobbin locations that are situated nearest to the winding machine on one creel side (8) and the winding beam (14) of the winding machine (3) there is arranged, at least for each thread group with the same distance to travel (L), a thread tension sensor (9) at which the actual thread tension value of a single thread can be continously measured,
   that the actual value can be compared with a nominal value in a comparator (30, 30'),
   and that if a deviation is found between the actual value and the nominal value, at least one drive motor can be activated by which the thread tension devices of the relevant group of threads can be adjusted in such a manner that the actual value approximates to the nominal value.
8. Bobbin creel according to claim 7, characterised in that the thread tension devices of one vertical row of bobbin locations can be activated by a common drive motor (21).
9. Bobbin creel according to claim 7, characterised in that each thread tension device can be activated by a drive motor (20) operatively associated therewith.
10. Bobbin creel according to any of claims 7 to 9, characterised in that for each vertical row of bobbin locations at least two thread tension sensors (9, 9') are arranged with which the thread tension of two threads in the row concerned can be individually measured, and that in a computer the measured actual values are used to constitute a mean actual value which is compared with the nominal value.
11. Bobbin creel according to any of claims 7 to 9, characterised in that each bobbin location has its own thread tension sensor operatively associated with it.
12. Bobbin creel according to any of claims 7 to 11, characterised in that the thread tension sensors incorporate a force measuring device featuring a measurement element which responds to elongation, and the force which is produced transversely to the thread can be measured on the diverted thread.
13. Bobbin creel according to any of claims 7 to 12, characterised in that a plurality of thread tension sensors are arranged in a row per creel tier, and each sensor is enclosed by a separate housing.
14. Bobbin creel according to any of claims 7 to 13, characterised in that operatively associated with each bobbin location, and arranged ahead of the thread tension device in the direction of thread travel, there is at least one pre-tensioning device (16, 17) for applying an additional braking force, which is adapted to be powered by the thread tension device or which can be permanently set as a default setting.
15. Bobbin creel according to claim 14, characterised in that the pre-tensioning device is an eyelet pre-tensioner (16) with a rotatable eyelet which swings out the thread, and/or a crepe pre-tensioner (17) with adjustable looping elements.
16. Bobbin creel according to any of claims 7 to 15, characterised in that the thread tension devices are looping-type thread tension devices with an adjustable looping angle, or disk brakes (19) with differentially loadable brake disks which act upon the thread.
17. Bobbin creel according to claim 14 or 15, characterised in that the pre-tensioner devices (16, 17) of a vertical row of bobbin locations are adapted to be adjusted by a common drive motor (21), and that the thread tension devices of the same row are adapted to be activated either via a common drive motor (21) or via drive motors (20) operatively associated with each thread tension device.
18. Bobbin creel according to any of claims 7 to 17, characterised in that the drive motors for the thread tension devices are stepping motors, and that they operate on the thread tension devices via a self-locking transmission.
19. Bobbin creel according to any of claims 7 to 18, characterised in that operatively associated with each bobbin location is at least one thread guard (27) to check for thread breakage or to monitor the thread's movement.
20. Bobbin creel according to any of claims 7 to 19, characterised in that operatively associated with each bobbin location is at least one optical signalling means (26) for identifying the bobbin location and/or as a creeling aid.
21. Bobbin creel according to any of claims 7 to 20, characaterised in that all the electrically actuatable means associated with one bobbin location, more particularly the drive motors for the thread tension devices, are operatively connected to a central controller via serial interfaces.
22. Bobbin creel according to any of claims 7 to 21, characterised in that the thread tension sensors (9) are arranged in a zone ahead of the coiling point of the winding machine (3) and between a lease and a reed (11) for merging the threads.
23. Bobbin creel according to claim 15, characterised in that the pre-tensioning device incorporates at least one crepe pre-tensioner which is adapted to be individually adjusted by a drive motor operatively associated therewith.
24. Bobbin creel according to claim 16, characterised in that the brake disks for the thread tension devices of a vertical row can be rotated by a common drive motor (40) which is adapted to be activated via the thread tension sensors and thread guards, respectively, in such a way that the drive motor of the vertical row concerned can be automatically deactivated without threads.

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