OPEN-END SPINNING DEVICE FOR AN OPEN-END SPINNING MACHINE AND OPEN-END SPINNING MACHINE

Abstract

An open-end spinning device for an open-end spinning machine includes an individually drivable spinning rotor having a rotor cup accommodated in a rotor housing. An individual drive for the spinning rotor arranged in a drive housing. A receptacle for a cover element that closes the rotor housing during spinning operations is provided. The rotor housing defines a central support part fixable to a machine frame of the open-end spinning machine. The rotor housing is formed as one piece with the drive housing and the receptacle for the cover element.

Description

FIELD OF THE INVENTION

The present invention relates to an open-end spinning device for an open-end spinning machine with an individually drivable spinning rotor, the rotor cup of which is accommodated in a rotor housing, with an individual drive for the spinning rotor, which is arranged in a drive housing, and with at least one receptacle for a cover element that closes the rotor housing during the spinning operation. The rotor housing is designed as a central support part, which is fixable at a machine frame of the open-end spinning machine. Moreover, the invention relates to an open-end spinning machine with a plurality of adjacently arranged workstations, each of which has an open-end spinning device of this type.

BACKGROUND

Various designs for mounting the open-end spinning devices at a machine frame of the open-end spinning machine have become known.

For example, it is known from DE 42 19 683 A1 to mount the individual components of the open-end spinning devices directly at longitudinal supports or longitudinal components of the machine frame of the open-end spinning device. The longitudinal components impart a high rigidity to the spinning machine. Since the units are mounted directly at the longitudinal components, the units retain their positions in relation to one another in the long term. The manufacture of the longitudinal components is correspondingly complex, however, since the attachment points for the components of the open-end spinning devices, for example, fastening bores, must be highly precisely introduced into the longitudinal components.

According to another concept, it is known to arrange the individual components of the open-end spinning device in a spin box frame, the spin box frame then being mounted at the machine frame of the textile machine. DE 197 17 737 A1 describes, for example, a spin box frame, which includes two lateral parts, which are fixable at the machine base frame, and bracing elements arranged between the lateral parts. The lateral parts are welded to the bracing elements. Preferably, a laser welding process is used for this purpose, so that a distortion of the frame does not occur as a result of the welding. Fastening bores for the components of the open-end spinning device can therefore be mounted in the individual components of the spin box frame already prior to the welding. Nevertheless, the configuration of the spin box frame made up of multiple components is complex.

In order to further reduce the production and the installation effort to install spinning devices, designs have also become known, in which the components of the open-end spinning device are mounted at a central support element. For example, DE 101 05 270 A1 provides that the spinning devices are arranged at a central functional support, which accommodates the components of the open-end spinning device and in turn is mounted at the machine frame of the spinning machine.

EP 1 664 401 B1 describes an embodiment in which the rotor housing of the open-end spinning device forms the central support element, which is mounted at the machine base frame. As a result, an additional functional support is not necessary. Further components of the open-end spinning device are then mounted at the rotor housing directly or by means of further supports.

SUMMARY OF THE INVENTION

A problem addressed by the present invention is that of providing an open-end spinning device, which is cost-effectively manufacturable and reduces the installation effort. Additional objects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.

The problem is solved with the aid of the invention as described and claimed herein.

An open-end spinning device for an open-end spinning machine has an individually drivable spinning rotor, the rotor cup of which is accommodated in a rotor housing, an individual drive for the spinning rotor, which is arranged in a drive housing, and at least one receptacle for a cover element that closes the rotor housing during the spinning operation. The rotor housing is designed as a central support part, which is fixable at a machine frame of the open-end spinning machine.

It is provided that the rotor housing is formed as one piece with the drive housing and the at least one receptacle for the cover element.

Moreover, an open-end spinning machine with a plurality of adjacently arranged workstations is provided, each of the workstations having an open-end spinning device of this type.

Due to the fact that the drive housing is formed directly as one piece with the rotor housing, additional installation work for mounting the drive housing at the rotor housing can be dispensed with. In addition, as a result, the correct alignment of the drive with respect to the axis of the spinning rotor can also be achieved without adjustment operations. This is advantageous, in particular, when further functions, such as, for example, a bearing point of a magnetic bearing, are integrated into the drive housing and/or the rotor housing, because these functions are then also aligned exactly with respect to the spinning rotor without adjustment operations.

In particular, however, due to the fact that the at least one receptacle for the cover element is formed as one piece with the rotor housing, the accuracy of the positioning of the fiber feed channel, which is arranged in the cover element, and the take-off nozzle with respect to the spinning rotor is considerably improved. Due to the one-piece design, the machining of the rotor housing, in particular, the formation of stop surfaces and fastening points or bores, can be carried out in a single clamping setup. As a result, an absolutely precise position of the components mounted at the rotor housing, in particular of the cover element with the opening roller, with respect to the spinning rotor can always be ensured. This not only simplifies the installation of the open-end spinning device, but is also particularly advantageous with respect to spinning technology and positively affects the yarn quality.

It is advantageous when the rotor housing has multiple, in particular two, receptacles for the cover element. The positioning of the cover element and of the components arranged thereon, such as the fiber feed channel and the take-off nozzle, with respect to the spinning rotor are further improved as a result. The receptacles are therefore referred to in the plural in the following. In principle, an embodiment having only one single receptacle, which is then preferably designed to be wider, is also conceivable, however. The following comments and the description of the figures therefore also expressly relate to a rotor housing with only one receptacle.

It is particularly advantageous when the rotor housing is formed as a cast part, wherein the drive housing and the receptacles for the cover element are integrally cast onto the rotor housing. The rotor housing can be particularly cost-effectively manufactured as a central support element as a result. In particular, it is advantageous when the rotor housing is formed as a diecast part. This enables the manufacture of the rotor housing with great precision. Provided this is necessary, the metal-cutting final machining can be carried out in a single clamping setup, as described above.

It is also advantageous when the rotor housing has fastening devices integrally formed thereon, in particular spacer bushes integrally formed thereon, for mounting at the machine frame. This also facilitates the mounting of the rotor housing at the machine frame and ensures that the open-end spinning device is correctly positioned with respect to the machine transverse direction.

According to one advantageous enhanced embodiment, the rotor housing has a cast-on frame, which includes the receptacles for the cover element. As a result, the rotor housing including the receptacles has a high rigidity, which ensures the exact positioning of the components with respect to one another also after a longer period of operation.

It is also advantageous when the drive housing, which is cast onto the rotor housing, has at least one bearing point for a magnetic bearing assembly for the spinning rotor. For example, at least one front bearing point for a front radial bearing of the magnetic bearing assembly can be integrated into the rotor housing, which forms the central support part. The magnetic bearing is also automatically exactly positioned with respect to the spinning rotor as a result. It is also conceivable, of course, to integrate not only the front bearing point, but also the rear bearing point and, if necessary, also a bearing point for the drive in the drive housing, which has been cast onto the rotor housing.

Moreover, it is advantageous when the receptacles for the cover element define a swivel axis and the cover element is accommodated in the receptacles of the rotor housing so as to be swivelable about the swivel axis. A swivelable design of the cover element makes it possible, in a particularly advantageous way, to bring the cover element out of an operating position, in which the cover element closes the rotor housing, into a maintenance position, in which the cover element permits access to the rotor housing.

It is also advantageous when the cover element includes an opening roller housing, which is preferably integrally formed on the cover element. The opening roller housing and, thereby, the opening roller, are also automatically correctly positioned with respect to the spinning device and the rotor housing as a result. It is therefore also particularly advantageous when the opening roller housing is formed as one piece with the cover element.

In order to be able to cost-effectively manufacture the cover element with the opening roller housing, it is also advantageous here when the cover element is formed as a cast part, wherein the opening roller housing is integrally cast onto the cover element.

In addition, it is also advantageous when the rotor housing includes a stop for the cover element for positioning the cover element in the axial direction of the spinning rotor. As a result, the take-off nozzle, which is accommodated in the cover element, and the rotor cup of the spinning rotor are automatically correctly positioned with respect to each other upon the closing of the cover element.

It is particularly advantageous when the stop is designed to be adjustable, wherein the stop is preferably formed as an adjusting screw. As a result, it is possible, with respect to spinning technology, to always set the correct position of the take-off nozzle with respect to the rotor cup and possibly compensate for tolerances that are present despite precise production.

It is also advantageous when the stop is arranged in an area of the rotor housing facing away from the receptacles for the cover element, in particular at an end area of the rotor housing situated opposite the receptacles. As a result, the stop is located at a greater distance from the swivel axis of the cover element, as the result of which the adjustment is facilitated.

According to another enhanced embodiment, it is advantageous when the rotor housing has at least one positioning device for positioning the cover element in an axial direction of the swivel axis. As a result, the cover element is automatically brought into the correct lateral position with respect to the swing axis upon closing and is fixed in this correct position when the cover element is closed.

It is advantageous when the positioning device is cast directly onto the rotor housing. As a result, an additional installation step for the positioning device is not necessary and the correct lateral alignment of the cover element with respect to the spinning rotor is always ensured as a result. Preferably, the positioning device is designed to be bifurcated. As a result, the cover element is correctly positioned in both axial directions of the swing axis.

Moreover, it is advantageous when the positioning device has a plastic coating. The plastic coating can, for example, dampen noises during the closing of the cover element and ensure a gentle closing in the positioning of the cover element.

BRIEF DESCRIPTION OF THE DRAWINGS

Further advantages of the invention are described with reference to the exemplary embodiments represented in the following, wherein:

FIG. 1 shows an open-end spinning machine in a schematic overview representation,

FIG. 2 shows a workstation of an open-end spinning machine with an open-end spinning device in a schematic, partially cut side view,

FIG. 3 shows a perspective representation of a rotor housing according to a first embodiment,

FIG. 4 shows a perspective representation of a rotor housing according to a second embodiment,

FIG. 5 shows a schematic, cut side view of a rotor housing with a cover element mounted thereon, and

FIG. 6 shows a schematic top view of a positioning device.

DETAILED DESCRIPTION

Reference will now be made to embodiments of the invention, one or more examples of which are shown in the drawings. Each embodiment is provided by way of explanation of the invention, and not as a limitation of the invention. For example features illustrated or described as part of one embodiment can be combined with another embodiment to yield still another embodiment. It is intended that the present invention include these and other modifications and variations to the embodiments described herein.

In the following description of the exemplary embodiments, features that are identical or at least comparable with respect to their design and/or mode of operation are provided with identical reference signs. Moreover, these features are explained in detail only at their first mention, while only the differences from the previously described exemplary embodiments are discussed in the subsequent exemplary embodiments. Moreover, for the sake of clarity, often only one or only a few of several identical components and/or features is/are labeled.

FIG. 1 shows a schematic front view of an open-end spinning machine 2. The open-end spinning machine 2 has, in a way known per se, a plurality of adjacently arranged workstations 34, which can be arranged between two frames 33 on one or also on both longitudinal sides of the open-end spinning machine 2. Each of the workstations 34 has, also in a known way, an opening roller 9 for opening a supplied fiber material 25 (see FIG. 2) into individual fibers and an open-end spinning device 1 for spinning the fiber material 25 into a thread 26. The spun thread 26 is then drawn off by means of a take-off device 27 and wound onto a package 29 by means of a winding device 28. For the purpose of controlling the processes at the open-end spinning machine 2, the spinning machine also has a control unit 35, which can interact with further control units 35 (not shown) arranged at the individual workstations 34.

FIG. 2 shows a detailed representation of a workstation 34 of an open-end spinning machine 2 of this type in a partially cut side view. As described above with respect to FIG. 1, the fiber material 25 is supplied to the open-end spinning device 1 and opened into individual fibers by means of the opening roller 9 and, from there, supplied to the open-end spinning device 1 through a fiber feed channel (not shown here).

The open-end spinning device includes, in a usual way, a spinning rotor 3, the rotor cup 4 of which revolves in a rotor housing 6 and the rotor shaft 5 of which is rotatably mounted in a drive housing 7. For this purpose, the spinning rotor 3 is driven by means of an individual drive 8, which is also arranged in the drive housing 7, and is mounted in a magnetic bearing assembly 16. The magnetic bearing assembly 16 includes a front radial bearing 17 and a rear radial bearing 18. Moreover, the spinning rotor 3 is supported in the axial direction by an axial bearing 19, which can also be designed as a magnetic bearing, but also as an air bearing or any other type of bearing. The rotor housing 6 is fixed, with the drive housing 7, at a machine frame 12 of the open-end spinning machine 2.

The rotor housing 6 is subjected to suction during the spinning operation, for the purpose of which the rotor housing 6 is connected to a suction channel 31 via a suction connection 30. During the spinning operation, the rotor housing 6 is closed with a cover element 11, which, in the present case, is fixed in receptacles 10 of the open-end spinning device 1 so as to be swivelable about a swivel axis 20. In order to open the rotor housing 6, the cover element 11 can therefore be swiveled out of the closed position represented by solid lines into the open position represented by dash-dotted lines. The cover element 11 is provided with an extension 36, which supports a thread take-off nozzle 37 and protrudes into the rotor cup 4 of the spinning rotor 3 during the spinning operation. The newly spun thread 26 is drawn off via the thread take-off nozzle 37. The extension 36 can also be designed as a channel insert adapter exchangeably arranged in the cover element 11, as shown in FIG. 5. In the present case, the cover element 11 simultaneously supports the opening roller 9, so that the cover element 11 is formed as one piece with an opening roller housing 21.

FIG. 3 shows a first embodiment of a rotor housing 6 according to the invention. The rotor housing 6 is designed as a central support part, which can be fixed by means of fastening devices, such as, for example, fastening bores 32, at a machine frame 12 (see FIG. 2) and at which further components of the open-end spinning device 2 can be arranged. The rotor housing 6 also includes, in addition to the housing for the spinning rotor 3 (see FIG. 2), the drive housing 7 and the receptacles 10 for the cover element 11. The receptacles 10 include, in the present case, bores, in which the cover element 11 is swivelably mounted and which, therefore, form a swivel axis 20 for the cover element 11.

These three components, rotor housing 6, drive housing 7, and receptacles 10, are formed as one piece with one another. Therefore, these can be advantageously designed as a highly compact cast part, which combines the aforementioned functions in one component and also enables the integration of numerous further functions and components of the open-end spinning device 1. It is particularly advantageous that all functional and contact surfaces and fastening devices, such as bores and the like, can be formed in one single clamping setup of the rotor housing 6. In other words, the rotor housing 6 needs to be clamped only one time for the machining. All metal-cutting machining steps can then be carried out on the rotor housing 6 without re-clamping the rotor housing 6. As a result, an extremely accurate position of the opening roller housing 21 and of the cover element 11 with respect to the rotor housing 6 can be ensured. The rotor housing 6 or the central support part can be produced highly cost-effectively despite the precise manufacture due to the design as a cast part and the machining in only one single clamping setup. Due to the highly precise positioning of the cover element 11 with the extension 36 and the thread take-off nozzle 37, considerable spinning technology-related advantages are also achieved and a high-quality yarn can be produced. Complicated adjustment operations at the open-end spinning device 1 can be dispensed with due to the one-piece design of the rotor housing 6 with the drive housing 7 and the receptacles 10.

In order to still support the exact positioning of the cover element 11 with respect to the rotor housing 6, a stop 22 can also be provided, which is explained in greater detail further below with reference to FIG. 5. By means of this stop 22, the cover element 11 can be correctly positioned with respect to the axial direction of the spinning rotor 3 during closing and in the closed position of the cover element 11.

FIG. 4 shows another embodiment of a rotor housing 6 according to the invention. In contrast to the rotor housing 6 from FIG. 3, the present rotor housing 6 has a cast-on, peripheral frame 14, which includes the receptacles 10 for the opening roller housing 21 and the cover element 11. The two receptacles 10 are connected by a cross brace. The frame 14 is therefore formed by the two receptacles 10 and, in the present case, a cross brace. As a result, the rotor housing 6 has a particularly high rigidity, which further supports the exact positioning of the cover element 11 with respect to the rotor housing 6 with the spinning rotor 3.

In the rotor housing 6 from FIG. 4, spacer bushes 13, as fastening devices, are cast directly onto the rotor housing 6. The spacer bushes 13 enable bolting directly onto a vertical wall of the machine frame 12 (see FIG. 2). The mounting of the rotor housing 6 at the open-end spinning device 1 is facilitated as a result. Of course, such spacer bushes 13 can also be cast on in the case of the rotor housing 6 from FIG. 3, in order to correctly position the rotor housing 6 at the machine frame 12.

A positioning device 23 is also apparent at the rotor housing 6 shown in the present case. By means of the positioning device 23, the cover element 11 can be positioned, during closing, in a correct position with respect to a direction transverse to the axis of the spinning rotor 3, i.e., in a width direction of the rotor housing 6 in the present case. In other words, by means of the positioning device 23, the cover element 11 is correctly positioned in an axial direction of the swivel axis 20 with respect to the rotor housing 6 and, thereby, the spinning rotor 3. The positioning device 23 can include only one positioning element 41 as shown in the present case. The positioning element 41 can be wrapped around, for example, by a bifurcated counterpart (not shown) at the cover element 11, as the result of which the cover element 11 is unambiguously positioned. Alternatively, it would also be conceivable to arrange a second positioning element 41 or a second positioning device 23 spaced apart from the positioning device 23 shown, in order to securely position the cover element 11 in both axial directions of the swivel axis 20. The positioning device 23 is also advantageously cast directly onto the rotor housing 6, as the result of which the correct positioning of the cover element 11 is always ensured without any adjustment effort. Similarly, due to the cast-on positioning device 23, the effort required to install the rotor housing 6 and the open-end spinning device 1 is further reduced.

FIG. 5 shows an open-end spinning device 1 in a schematic, cut representation. In contrast to FIGS. 3 and 4, the cover element 11 is arranged in the receptacles 10, so that the two components, the rotor housing 6 and the cover element 11, are represented in interaction. As described above with reference to FIG. 2, the cover element 11 also includes the opening roller housing 21 integrally formed onto the cover element 11 and is swivelably mounted at the receptacles 10 of the rotor housing 6, for example, by means of tabs 38. The extension 36 of the cover element 11 is also apparent. The extension 36 of the cover element 11 is designed in the present case as a channel insert adapter, which is insertable into the cover element 11.

According to the present representation, the spinning rotor 3 is shown in its operating position accommodated in the rotor housing 6. The rotor cup 4 is located within the rotor housing 6, while the rotor shaft 5 is located within the drive housing 7, which has been cast onto the rotor housing 6.

Moreover, the front radial bearing 17 of the magnetic bearing assembly 16 is also apparent in the present representation. As is apparent from FIG. 5, the drive housing 7 and, thereby, the rotor housing 6 connected to the drive housing 7 include the front bearing point 15 for the front radial bearing 17. Fastening bores 32 are provided in the drive housing 7 for this purpose, the fastening bores 32 enabling a mounting of the front radial bearing 17. According to the present representation, the drive housing 7 also includes fastening bores 32, which enable a mounting of the individual drive 8 in the drive housing 7. The rear radial bearing 18 (not visible here) can be mounted, for example, in a cover element 11, which is insertable into the drive housing 7. Alternatively, it would also be possible, however, to also mount the rear radial bearing 18 directly in the drive housing 7.

Moreover, a stop 22 for the cover element 11 is also provided in the open-end spinning device shown here. By means of the stop 22, the cover element 11 and, thereby, the thread take-off nozzle 37 are correctly positioned with respect to the axis of the spinning rotor 3. The stop 22 is designed in the present case as an adjusting screw, which is arranged so as to be axially parallel to the axis of the spinning rotor 3. Preferably, the stop 22 is arranged centrally with respect to the open-end spinning device 1 over the axis of the spinning rotor 3, as is also apparent from FIGS. 3 and 4.

It is also advantageous when the stop 22 is arranged in an area of the rotor housing 6 facing away from the receptacles 10 for the cover element 11, as shown in the present case. For example, in the present case, the stop 22 is arranged in an end area 39 of the rotor housing 6 situated opposite the receptacles 10. As a result, the stop 22 or the adjusting screw has a great distance to the swivel axis 20, which facilitates the adjustment of the stop 22. By means of such an adjustable stop 22, the distance between the thread take-off nozzle 37 and the spinning rotor 3 can be set in various ways and, for example, adapted to spinning technology-related conditions in a certain application.

It is also possible to fix the position of the cover element 11 with respect to the rotor housing 6 one time after the initial installation of the cover element 11 and, as a result, take possible tolerances into account, which tolerances can arise due to the installation of the magnetic bearing assembly 16 and the accommodation of the spinning rotor 3. It can also be provided that the stop 22 is not to be displaced again after the initial adjustment of the stop 22. If the stop 22 is designed as an adjusting screw, the adjusting screw can also be secured against twisting, for example. Screw locking devices, for example, or also screws that include a special head are also conceivable in this case.

In order to also prevent the stop 22, specifically the adjusting screw in this case, from twisting during operation, the adjusting screw can also be clamped against the rotor housing 6 with an O-ring 40 as shown here.

FIG. 6 also shows another embodiment of a positioning device 23 in a schematic top view. In contrast to the positioning device 23 from FIG. 4, the present positioning device 23 includes two positioning elements 41 situated opposite each other. In the present case, the positioning device 23 is therefore designed to be bifurcated. As the cover element 11 is closed, a corresponding counterpart (not shown) arranged at the cover element 11 enters the space between the two positioning elements 41 as indicated by the arrow, as the result of which the cover element 11 in turn is positioned exactly in both axial directions of the swivel axis 20 (see FIGS. 3 and 4). The positioning device 23 shown in the present case also has a plastic coating 24, which is applied on each of the positioning elements 41. The positioning of the thread take-off nozzle 37 with respect to the rotor cup 4 of the spinning rotor 3 is further improved as a result.

The present invention is not limited to the represented and described exemplary embodiments. Modifications within the scope of the claims are also possible, as is any combination of the described features, even if they are represented and described in different parts of the description or the claims or in different exemplary embodiments, provided no contradiction to the teaching of the independent claims results.

LIST OF REFERENCE SIGNS

1 open-end spinning device2 open-end spinning machine3 spinning rotor4 rotor cup5 rotor shaft6 rotor housing7 drive housing8 individual drive9 opening roller10 receptacle11 cover element12 machine frame13 spacer bush14 frame15 bearing point16 magnetic bearing assembly17 front radial bearing18 rear radial bearing19 axial bearing20 swivel axis21 opening roller housing22 stop23 positioning device24 plastic coating25 fiber material26 thread27 take-off device28 winding device29 package30 suction connection31 suction channel32 fastening bore33 frame34 workstation35 control unit36 extension37 thread draw-off nozzle38 tab39 end area

40 O-ring

41 positioning element

Claims

1-15. (canceled)

16. An open-end spinning device for an open-end spinning machine, comprising: an individually drivable spinning rotor having a rotor cup accommodated in a rotor housing;an individual drive for the spinning rotor arranged in a drive housing;at least one receptacle for a cover element that closes the rotor housing during spinning operations;the rotor housing defining a central support part fixable on a machine frame of the open-end spinning machine; andthe rotor housing formed as one piece with the drive housing and the at least one receptacle for the cover element.

17. The open-end spinning device of claim 16, wherein the rotor housing is formed as a cast part such that the at least one receptacle for the cover element is integrally cast onto the rotor housing.

18. The open-end spinning device of claim 16, wherein the rotor housing comprises fastening devices integrally formed thereon to fix the rotor housing to the machine frame.

19. The open-end spinning device of claim 16, wherein the rotor housing comprises a cast-on frame that defines the at least one receptacle for the cover element.

20. The open-end spinning device of claim 16, wherein the drive housing comprises at least one bearing point of a magnetic bearing assembly for the spinning rotor.

21. The open-end spinning device of claim 16, wherein the at least one receptacle for the cover element defines a swivel axis, and further comprising the cover element accommodated in the at least one receptacle and swivelable about the swivel axis.

22. The open-end spinning device of claim 21, wherein the cover element comprises an opening roller housing integrally formed on the cover element.

23. The open-end spinning device of claim 22, wherein the cover element is formed as a cast part, wherein the opening roller housing is integrally cast onto the cover element.

24. The open-end spinning device of claim 21, wherein the rotor housing comprises a stop for the cover element to position the cover element in the axial direction of the spinning rotor.

25. The open-end spinning device of claim 24, wherein the stop is adjustable.

26. The open-end spinning device of claim 24, wherein the stop is arranged in an area of the rotor housing facing away from the at least one receptacle for the cover element.

27. The open-end spinning device of claim 21, wherein the rotor housing comprises a positioning device that locates the cover element in an axial direction of the swivel axis.

28. The open-end spinning device of claim 27, wherein the positioning device is cast directly onto the rotor housing.

29. The open-end spinning device of claim 28, wherein the positioning device comprises a plastic coating.

30. An open-end spinning machine, comprising: a plurality of adjacently arranged workstations; andwherein each of the workstation comprises the open-end spinning device of claim 16.