EP1718555B1 - Method and device for winding several threads - Google Patents

Abstract

The invention relates to a method for winding several threads to form bobbins. The bobbins (9.1; 9.2) are held on two adjacent parallel bobbin spindles (7.1; 7.2) and are driven in opposite directions during the winding of the threads with predetermined surface speeds. During said process two respective pressure rolls (6.1; 6.2), which are rotatably mounted and lie against the periphery of the bobbins (9.1; 9.2), co-operate with the bobbin spindles (7.1; 7.2). To maintain both bobbins (9.1; 9.2) at a speed that is as similar as possible during the winding of the threads on both bobbin spindles (7.1; 7.2), the rotational speed of one of the pressure rolls is detected (6.1; 6.2) in order to control the surface speed of the bobbins (9.1; 9.2) and to collectively modify the drive speed of both bobbin spindles (9.1; 9.2) in accordance with the detected rotational speed, in such a way that the detected rotational speed of the pressure roll (6.1;6.2) remains essentially constant.

Description

The invention relates to a method for winding a plurality of threads into coils according to the preamble of claim 1 and to an apparatus for carrying out the method according to the preamble of claim 10.

In the production of synthetic threads, there is an increasing tendency to observe that a multiplicity of threads are spun parallel to one another in a spinning position simultaneously from a polymer melt and then wound up into coils. Thus, it is known to spin ten, twelve, sixteen or more threads in parallel while winding coils. The winding of the threads can be done by winding machines, in which the coils are held and wound on a winding spindle. For larger coil widths and high number of threads such winding machines require correspondingly long winding spindles. Therefore, new concepts have been developed in which the threads are wound on two parallel winding spindles simultaneously to form coils. Such a method and such a device are known from WO 03/068648 A1 known.

In the known method and the known device, the threads are simultaneously wound on two adjacent winding spindles to form coils. For this purpose, the winding spindles are driven by a respective spindle drive. Each of the winding spindles is assigned to one of two pressure rollers, which are each held by a rocker radially movable to the winding spindle. During the winding of the threads into coils, the pressure rollers abut the circumference of the coils. As the bobbin diameter increases, both the pressure roller and the winding spindle can be changed in their position. As a further degree of freedom, the movably held pressure rollers are additionally movable by a slide radially to the winding spindles. Taking into account that usually the threads wound at constant winding speed to coils Be it, it is also necessary that the coils are driven by the winding spindle as possible with constant peripheral speeds. Due to the large number of degrees of freedom, however, it is unavoidable that the coils of the two winding spindles have differences in the coil construction.

Although is out of the DE 40 18 095 A1 a method for winding threads on a winding spindle, in which the rotational speed of the winding spindles in dependence on the rotational speed of the pressure roller is controlled such that the peripheral speed in each case assumes a constant value. Such control of the peripheral speed of the growing coils on each of the winding spindles inevitably leads to different settings and windings due to the large number of freedom of movement. The known in the prior art method and the known device thus have the disadvantage that each of the winding spindles produces coils with different coil structures. Thus, deviations in the peripheral speeds of the coils lead directly to changed thread tensions during winding.

It is an object of the invention to provide a method and a device of the generic type in which or in which wound on the two winding spindles with simultaneous winding of the threads substantially uniform coils.

A further object and object of the invention is to produce as much as possible thread tensions by winding on the threads of the yarn sheet to be wound up.

The object is achieved by a method having the features of claim 1 and by a device having the features of claim 10.

Advantageous developments of the invention are defined by the features and feature combinations of the respective subclaims.

The invention is characterized in that the change in the drive speeds of the winding spindles during the winding of the coils are controlled by a common control loop. Thus, the changes in the drive speeds of the winding spindles can be performed synchronously. The control of the winding spindle drives takes place at the same time. For this purpose, the rotational speed of one of the pressure rollers is first detected. By means of a control device, a collective change in the drive speeds of the winding spindles is carried out in such a way that the rotational speed of the detected pressure roller remains substantially constant in dependence on the respective measured rotational speed of the pressure roller. Thus, the second non-integrated in the control loop pressure roller is automatically placed in the same state as the monitored by a sensor pressure roller.

For carrying out the method, the device according to the invention has a rotational speed sensor which is assigned to one of the pressure rollers in order to detect their rotational speeds. The speed sensor is connected to the spindle drives of the winding spindles by a control device to a control loop. The sensor signal can thus be used advantageously for controlling both spindle drives.

In order to operate as possible both winding spindles with identical speed and thus identical peripheral speeds of the coils, the winding spindles are synchronously driven and controlled according to an advantageous embodiment of the invention. For this purpose, the spindle drives are preferably formed by two synchronous motors and a control unit, wherein the control unit is connected to the control device. This development is characterized in particular by the flexibility in the arrangement of the pressure rollers and the winding spindles. Thus, the pairings of pressure roller and winding spindle could both side by side as well as on top of each other. By detecting the speed change of one of the pairings between the spindle and the pressure roller, the synchronous drives of the winding spindles inevitably lead to the same control settings in the undetected pairing.

When winding and depositing the threads on the circumference of the coils slip phenomena are possible between the peripheral surface of the coil and the peripheral surface of the pressure roller. In order to avoid that such slip phenomena develop differently at the two pressure rollers, the development of the invention is preferably used, in which the pressure rollers are mechanically or electrically coupled to each other such that both pressure rollers rotate at the same speed. To couple the pressure rollers are interconnected by a gear means. The gear means could be formed mechanically or electrically to achieve the speed adjustment of the two pressure rollers.

In this case, the pressure rollers can also drive in opposite directions by an external drive, which favors in particular Spulwechselvorgänge. Preferably, however, the external drive of the pressure rollers is suitable for producing specific load ratios between the driven coils and the pressure rollers. Thus, the external drive of the pressure rollers can be designed such that always a promotional component or a braking component act on the circumference of the coils. By specifying a load ratio, the thread tension of the wound-up threads can advantageously be influenced, since defined slip phenomena between the pressure rollers and the coils can be set.

The external drives of the pressure rollers are also suitable to drive the winding spindles by friction, so that the spindle drives for direct drive of the winding spindles could be omitted.

Due to the increase in the bobbin diameter, additional superimposed deflection movement between the winding spindles and the pressure rollers is to be carried out. Such evasive movements can be performed individually or collectively, in principle, a contact between the pressure roller and the circumference of the coil is not lost. A control option for maintaining the contacts is advantageously given by the development of the invention, in which the winding spindles are driven by two asynchronous motors. Due to the load ratio predetermined by the external drives of the pressure rollers, the asynchronous motors are operated in the same frequency range. Thus, an adjustment of the operating states of the asynchronous motors would immediately detected misalignments that cause a lack of contact between the pressure roller and the winding spindle detected. Accordingly, control signals could be generated from this, which carry out a correction of the evasive movement.

The evasive movements can be carried out in a simple manner such that during the winding, the pressure rollers are guided together by a movable holder. Thus, the same settings of the contact pressures can be generated in the two winding units.

However, it is also possible to independently guide the pressure rollers radially to the coils movable. Here, the pressure rollers are preferably held by movable rockers, which are held independently pivotable on the machine housing or the movable holder.

In principle, however, there is also the possibility that the pressure rollers are held stationary and the evasive movements are performed exclusively by the winding spindles. For this purpose, the winding spindles can preferably be guided synchronously in each case by means of two movable spindle carriers.

However, it is also possible, the deflection movement between the pressure rollers and the winding spindles for growing the coil both by a movement to perform the pressure rollers and by a movement of the winding spindles. The use of a movable spindle carrier in the form of a bobbin revolver also has the advantages that a second winding spindle can be held in each winding station in order to be able to alternately guide the two winding spindles into a winding area and a changing area.

The method according to the invention is explained in more detail below with reference to some embodiments of the device according to the invention with reference to the attached figures.

Fig. 1

eine Vorderansicht und

Fig. 2

eine schematische Rückansicht eines ersten Ausführungsbeispiels der erfindungsgemäßen Vorrichtung zur Durchführung des erfindungsgemäßen Verfahrens;

Fig. 3, 4 und 5

schematisch weitere Ausführungsbeispiele der erfindungsgemäßen Vorrichtung zur Durchführung des erfindungsgemäßen Verfahrens.

They show:

Fig. 1

a front view and

Fig. 2

a schematic rear view of a first embodiment of the device according to the invention for carrying out the method according to the invention;

Fig. 3, 4 and 5

schematically further embodiments of the device according to the invention for carrying out the method according to the invention.

In Fig. 1 and 2 a first embodiment of the device according to the invention for carrying out the method according to the invention is shown. This shows Fig. 1 a front view and Fig. 2 a schematic of the rear view of the embodiment.

The construction of the exemplary embodiment is first described with reference to FIG Fig. 1 explained.

The embodiment of the device according to the invention has two winding stations 29.1 and 29.2, which are formed side by side in a machine frame 12. Here, the winding units 29.1 and 29.2 are mirror images of a central plane of symmetry. Thus, the right winding unit 29.1 is made a rotatably mounted in the machine frame 12 spindle carrier 10.1. On the spindle carrier 10.1 a first cantilevered winding spindle 7.1 and 180 ° offset a second cantilevered winding spindle 11.1 held. Here, the first winding spindle 7.1 is in an operating position for winding one or more threads. The second winding spindle 11.1 is in a change position for replacing a full bobbin against an empty winding tube.

Mirrored to the spindle carrier 10.1 is in the second winding unit 29.2 a second arranged in the same or offset plane spindle carrier 10.2 held in the machine frame 12. The spindle carrier 10.2 carries the projecting winding spindles 7.2 and 11.2. In the illustrated operating situation, the winding spindle 7.2 is in the operating position and the winding spindle 11.2 in a change position.

Each of the spindle carriers 10.1 and 10.2 is preceded by a pressure roller 6.1 and 6.2 in the yarn path. In the winding unit 29.1 acts while the pressure roller 6.1 with the winding spindle 7.1 together to wrap a thread 1.1 to a coil 9.1. During the winding of the thread 1.1, the pressure roller 6.1 is located on the circumference of the coil to be wound on 9.1.

Accordingly, in the winding unit 29.2, the pressure roller 6.2 cooperates with the winding spindle located in the operating position in this case 7.2 in order to wind a second yarn 1.2 to the coil 9.2. Again, the pressure roller 6.2 is at the periphery of the coil to be wound 9.2.

The pressure rollers 6.1 and 6.2 are rotatably mounted and fixed to a holder 13. The traversing device 13 carries a traversing device 6 and upstream of the pressure rollers 6.1 and 6.2. The traversing device 4 is arranged in a median plane between the winding stations 29.1 and 29.2 and has, for each winding station 29.1 and 29.2, a traversing yarn guide 5.1 and 5.2, through which the tapered yarns 1.1 and 1.2 be moved back and forth within a traverse stroke.

The traversing device 4 can be formed for example by a Kehrgewindewelle having one or more grooves on the circumference for guiding the traversing yarn guides 5.1 and 5.2.

On an upper side of the holder 13, a yarn guide carrier 3 is provided, which carries the yarn guides 2.1 and 2.2. Here, the yarn guide is 2.1 associated with the winding unit 29.1 and the yarn guide 2.2 associated with the winding unit 29.2.

The holder 13 is formed by a carriage 15 and the carriage guides 14.1 and 14.2 vertically movable. The carriage 15 is held by two force transmitters 16.1 and 16.2 in the carriage guides 14.1 and 14.2 such that the pressure rollers 6.1 and 6.2 abut each with a predetermined contact force during the winding of the threads 1.1 and 1.2 to the respective coils 9.1 and 9.2.

At the in Fig. 1 In the embodiment shown in the winding units 29.1 and 29.2 one thread 1.1 and 1.2 are wound into a coil 9.1 and 9.2, respectively. In principle, however, such devices are used to wind several threads simultaneously to form coils. For this purpose, a plurality of winding tubes 8.1 and 8.2 attached one behind the other are held on the winding spindles 7.1 and 7.2. In this case, 8, 10 or even more bobbin tubes can be held simultaneously by a winding spindle 7.1 and the winding spindle 7.2. Here, the winding spindles, the pressure rollers and the traversing device on a corresponding projecting length, so that a plurality of threads can be simultaneously wound parallel to each other.

For the method according to the invention, however, it is irrelevant whether one thread (as shown) or several threads are wound into coils in the winding stations 29.1 and 29.2.

To further explain the first embodiment, the drive situation of the winding spindles 7.1 and 7.2 is based on the Fig. 2 explained. Due to the clarity were in the Fig. 2 only required for carrying out the method according to the invention device parts of the winding units 29.1 and 29.2 shown schematically from the rear view.

In the winding unit 29.2, the winding spindle 7.2 is coupled via a spindle end 22.2 with a spindle drive 23.2. The spindle drive 23.2 is associated with a control unit 24.2, which is connected to a higher-level control device 21. The wound on the winding spindle 7.2 coil 9.2 is shown here by dashed lines. At the periphery of the coil 9.2 is the freely rotatably mounted pressure roller 6.2, which is also shown in dashed lines. The pressure roller 6.2 has a roller end 18.2. The roller end 18.2 is associated with a speed sensor 20, by which the rotational speed of the pressure roller 6.2 can be detected. The rotational speed sensor 20 is connected to the control device 21.

In the other winding unit 29.1, the winding spindle 7.1 is coupled by the spindle end 22.1 with the spindle drive 23.1. The spindle drive 23.1 is associated with a control unit 24.1, which is also connected to the control device 21. The coil 9.1, also shown in dashed lines, which is formed on the circumference of the winding spindle 7.1, is in contact with the second pressure roller 6.1. The pressure roller 6.1 of the second winding unit 29.1 is also held freely rotatable. The pressure roller 6.1 is coupled with a roller end 18.1 by a gear means 19 with the pressure roller 6.2 of the other winding unit 29.2. The gear means 19 is mechanically formed in this embodiment by a belt or a chain, so that both pressure rollers 6.1 and 6.2 both winding units rotate at the same speed.

Further explanation will now be given to both FIGS. 1 and 2 Referenced. To wind the thread 1.1 in the winding unit 29.1, the winding spindle 7.1 by the spindle drive 23.1 clockwise ( Fig. 1 ). The pressure roller 6.1 abuts the circumference of the coil to be wound 9.1 and is driven by friction in the opposite sense.

In the winding unit 29.2, the winding spindle 7.2 by the spindle drive 23.2 counterclockwise ( Fig. 1 ) to wind the yarn 1.2 to the bobbin 9.2. Here, the pressure roller 6.2 rotates on the circumference of the coil 9.2 clockwise with the corresponding speed of the pressure roller 6.1. The rotation transmission between the pressure rollers 6.1 and 6.2 is carried out by the gear means 19. Both winding units 29.1 and 29.2 are wound synchronously, so that takes place at each of the winding spindles 7.1 and 7.2, an identical structure of the coils 9.1 and 9.2.

In order to obtain a constant winding speed of the threads 1.1 and 1.2, the rotational speed of the pressure roller 6.2 is continuously detected by the speed sensor 20 and the control device 21 abandoned. In the control device 21, a target speed of the pressure roller 6.2 is deposited. As soon as between the sensed actual rotational speed of the pressure roller 6.2 and the stored target rotational speed of the pressure roller 6.2 an impermissible deviation is detected, a control signal is generated and the control units 24.1 and 24.2 abandoned. The control units 24.1 and 24.2 change the drive speeds of the spindle drives 23.1 and 23.2 in the desired sense that results in the pressure roller 6.2 a changed actual rotational speed. Thus, it is possible to set a constant peripheral speed of the coils 9.1 and 9.2 during the entire winding of the threads 1.1 and 1.2. The spindle drives 23.1 and 23.2 are preferably formed by asynchronous motors. The number of recesses of the asynchronous motors is preferably effected by a multiplex circuit, so that only one input is required at the control device.

During the winding of the threads 1.1 and 1.2 due to the growth of the coils 9.1 and 9.2 required evasive movement can be in this Execute embodiment by both the holder 13 held movably and by the movably held winding spindles 7.1 and 7.2. Due to the fixed arrangement of the pressure rollers 6.1 and 6.2 on the holder 13, the growth of the coils 9.1 and 9.2 can be done synchronously by movement of the carriage 15.

The rotary drives of the spindle carriers 10.1 and 10.2, not shown here, are preferably likewise operated synchronously in order to execute an evasive movement, for example, both spindle carriers 10.1 and 10.2 can be coupled together by means of a transmission and activated by a rotary drive.

In Fig. 3 is a further embodiment for controlling the Spulspindelantriebe both winding units according to the inventive method shown schematically. The embodiment according to Fig. 3 is essentially identical to the embodiment according to Fig. 1 and Fig. 2 so that only the differences are explained below. In the winding unit 29.1, the winding spindle 7.1 and the pressure roller 6.1 cooperate to wind up the coil 9.1. The pressure roller 6.1 is freely rotatably mounted, wherein the roller end 18.1 is associated with a speed sensor 20. The speed sensor 20 is connected to the spindle drives 23.1 and 23.2 by the control device 21 to form a control loop. For this purpose, a control unit 24 is assigned to the spindle drives 23.1 and 23.2. The spindle drives 23.1 and 23.2 are each formed by synchronous motors. The control unit 24 is coupled to the control device 21.

In the second winding unit 29.2, the winding spindle 7.2 and the pressure roller 6.2 act together.

In the embodiment, both pressure rollers are 6.1 and 6.2 at the periphery of the coils to be wound 9.1 and 9.2. The coils 9.1 and 9.2 are each driven by the winding spindles 7.1 and 7.2 and the associated spindle drives 23.1 and 23.2. Thus, the rotational speed of the pressure rollers 6.1 and 6.2 determined by the respective peripheral speed of the coils 9.1 and 9.2. The rotational speed of the pressure roller 6.1 is detected by the speed sensor 20 and the control device 21 abandoned. In the control device 20, an actual target comparison is performed. In case of impermissible difference, a control signal is generated in the control device 21, which is output in the control unit 24. By the control unit 24, the spindle drives 23.1 and 23.2 operated with changed input speed. The change in the drive speed is synchronous in both winding units 29.1 and 29.2, wherein the change in the peripheral speed and thus the change in the rotational speed of the pressure roller 6.1 in the winding unit 29.1 is effective and signals the speed sensor of the controller 21. In contrast to the previous embodiment, both pressure rollers 6.1 and 6.2 of the adjacent winding units 29.1 and 29.2 are independently rotatable independently. This results in a high degree of flexibility in the arrangement of the assemblies of the two winding units, which is not limited to a horizontally designed arrangement.

In the 4 and 5 , Further embodiments of the inventive device for carrying out the method according to the invention are shown schematically, wherein both embodiments are substantially identical to the embodiment according to Fig. 1 are. In that regard, the previous description to Fig. 1 And only explains the differences below.

At the in Fig. 4 illustrated embodiment, the pressure rollers are 6.1 and 6.2 of the two winding units 29.1 and 29.2 driven by a third drive 25. Here, the external drive 25 is formed by a belt drive 26 and an electric motor 28, wherein the electric motor 28, a control unit 27 is associated. The control unit 27 is coupled to the control device 21. By the external drive 25, the pressure rollers 6.1 and 6.2 are driven in opposite directions in the winding required for winding.

The drive of the winding spindle 7.1 and 7.2 and the regulation of the drive speeds of the winding spindles according to the embodiment according to Fig. 2 , In that regard, reference is made to the preceding description, wherein the winding units 29.1 and 29.2 are reversed in their assignment for monitoring the speed.

By the external drive 25 can be a load ratio between the drives of the pressure rollers 6.1 and 6.2 and the drives of the winding spindles 7.1 and 7.2 set. Thus, the pressure rollers 6.1 and 6.2 both driving and braking effect on the coil surfaces of the coils 9.1 and 9.2 act. The duty ratio is abandoned by the controller 21. In order to avoid misconduct in the form of missing contacts in the superimposed evasive movement of the winding spindles or the pressure rollers, an adjustment of the actual load conditions can additionally be carried out within the control device 21. For this purpose, the operating conditions, in particular the drive frequencies of the spindle drives 23.1 and 23.2, via the control units 24.1, 24.2 of the control device 21 abandoned. The spindle drives 23.1 and 23.2 are designed for this purpose as asynchronous motors. In the event that both winding units 29.1 and 29.2 wind with the prescribed setting, there are no significant differences in the operating states of the spindle drives 23.1 and 23.2. In the event that one of the drives has a different drive frequency, a correction of the evasive movement is performed, so that a possibly missing contact is recoverable.

This in Fig. 5 illustrated embodiment is essentially identical to the embodiment according to Fig. 3 , In this case, the pressure rollers 6.1 and 6.2 are driven by a third drive 25, which in this case is formed by two electric motors 28.1 and 28.2 and an associated control device 27. Thus, the electrical coupling of the pressure rollers 6.1 and 6.2 can be combined with a third drive 25.

The inventive method and the device according to the invention is not limited to the Fig. 1 illustrated arrangement of the individual units. In principle, in particular the pressure rollers can be kept in the winding units by swinging radially movable to the winding spindle. The holder of the winding spindles and the pressure rollers is essentially only relevant to the execution of the evasive movement. Regardless of the evasive movement, however, the peripheral speed of the bobbins must always be adjusted in such a way that the threads can be wound up with the same take-up speed and thus essentially with constant thread tension.

LIST OF REFERENCE NUMBERS

1.1, 1.2

thread

2.1,2.2

thread guides

3

Yarn guide

4

traversing

5.1, 5.2

Traversing thread guide

6.1, 6.2

pressure roller

7.1, 7.2

spindles

8.1,8.2

bobbin

9.1,9.2

Kitchen sink

10.1, 10.2

spindle carrier

11.1, 11.2

Spindles in rest position

12

machine frame

13

holder

14.1, 14.2

carriage guide

15

carriage

16.1, 16.2

force transmitter

17

locking device

18.1, 18.2

roll end

19

gear means

20

Speed sensor

21

control device

22.1,22.2

spindle end

23.1, 23.2

spindle drive

24, 24.1, 24.2

control unit

25

External drive

26

belt drive

27

control unit

28.1,28.2

electric motor

29.1, 29.2

winding station

Claims (19)

1. A method for winding a plurality of threads into bobbins, in which the bobbins are held on two bobbin spindles arranged parallel and next to one another, in which the bobbin spindles are driven contradirectionally in such a way that, during the winding of the threads, the bobbins rotate contradirectionally at predetermined circumferential speeds, in which the bobbin spindles cooperate in each case with a rotatable pressure roller, and in which the pressure rollers bear against the circumference of the bobbins, characterized in that, to control the circumferential speeds of all bobbins, the rotational speed of one of the pressure rollers is detected and monitored, and in that the drive rotational speeds of the two bobbin spindles are synchronously changed collectively as a function of the detected rotational speed, in such a way that the rotational speed of the pressure roller, the rotational speed of which is detected, remains essentially constant.
2. The method as claimed in claim 1, characterized in that the bobbin spindles are driven and controlled synchronously.
3. The method as claimed in claim 1 or 2, characterized in that the pressure rollers are coupled to one another mechanically or electrically in such a way that both pressure rollers rotate at the same rotational speed.
4. The method as claimed in one of claims 1 to 3, characterized in that the pressure rollers are additionally driven contradirectionally by means of an external drive.
5. The method as claimed in claim 4, characterized in that a driving or braking load condition is set in each case between the external drive of the pressure rollers and the spindle drive of the bobbin spindles.
6. The method as claimed in claim 5, characterized in that the bobbin spindles are driven in each case by an asynchronous motor, and in that the drive frequency of the asynchronous motors is monitored in order to maintain the load condition.
7. The method as claimed in one of the abovementioned claims, characterized in that, during winding, the pressure rollers are guided jointly by means of a movable holder in order to execute deflecting movements for the growth of the bobbins.
8. The method as claimed in one of the abovementioned claims, characterized in that the pressure rollers are guided independently of one another so as to be movable radially with respect to the bobbins.
9. The method as claimed in one of the abovementioned claims, characterized in that the bobbin spindles are guided synchronously or independently of one another by means of two movable spindle carriers in order to execute deflecting movements for the growth of the bobbins.
10. A device for carrying out the method as claimed in one of claims 1 to 9, with two bobbin spindles (7.1, 7.2), arranged next to one another, for receiving in each case at least one bobbin tube (8.1, 8.2) for the simultaneous winding of threads (1.1, 1.2) into bobbins (9.1, 9.2), with two spindle drives (23.1, 23.2), assigned to the bobbin spindles (7.1, 7.2), for the contradirectional drive of the two bobbin spindles (7.1, 7.2), and with two rotatably mounted pressure rollers (6.1, 6.2) which bear against the circumference of the bobbins (9.1, 9.2) during winding, characterized in that one of the pressure rollers (6.1) is assigned a rotational speed sensor (20) for detecting and monitoring the rotational speed of the pressure roller (6.1), and in that the rotational speed sensor (20) and collectively both spindle drives (23.1, 23.2) of the bobbin spindles (7.1, 7.2) are connected by means of a control device (21) so as to form a closed loop.
11. The device as claimed in claim 10, characterized in that the spindle drives (23.1, 23.2) are formed by two synchronous motors and a control apparatus (24), the control apparatus (24) being connected to the control device (21).
12. The device as claimed in claim 10 or 11, characterized in that the pressure rollers (6.1, 6.2) are connected to one another by a gearing means (19), in such a way that both pressure rollers (6.1, 6.2) rotate contradirectionally at the same rotational speed.
13. The device as claimed in one of claims 10 to 12, characterized in that an external drive (25) is provided in order to drive the pressure rollers (6.1, 6.2) contradirectioinally separately or jointly.
14. The device as claimed in claim 13, characterized in that the external drive (25) is formed by an electric motor (28) which cooperates with the gearing means (19).
15. The device as claimed in claim 13, characterized in that the external drive (25) is formed by two separate electric motors (28.1, 28.2) which can be activated jointly by a control apparatus (27).
16. The device as claimed in one of claims 10 to 15, characterized in that the spindle drives (23.1, 23.2) are formed by two asynchronous motors with one control apparatus (24) or with two assigned control apparatuses (24.1, 24.2), the control apparatuses (24, 24.1, 24.2) being connected to the control device (1).
17. The device as claimed in one of claims 10 to 16, characterized in that the pressure rollers (6.1, 6.2) are arranged on a movable holder (13), which holder (13) is arranged on a slide (15) and guides the pressure rollers (6.1, 6.2) in the radial direction with respect to the bobbin spindles (7.1, 7.2) by means of slide guides (14.1, 14.2).
18. The device as claimed in one of claims 10 to 17, characterized in that the pressure rollers are held in each case on two movable rockers, which rockers guide the pressure rollers independently of one another in the radial direction with respect to the bobbin spindles.
19. The device as claimed in one of claims 10 to 18, characterized in that the bobbin spindles (6.1, 6.2) are held in each case on a movable spindle carrier (10.1, 10.2), which spindle carriers (10.1, 10.2) guide the bobbin spindles in the radial direction with respect to the pressure rollers by means of a common drive or by means of separate drives.

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