EP0416349A2 - Open end spinning machine - Google Patents

Abstract

During cleaning, a pulsating air stream can be fed to a spinning rotor (1) by means of a switching device (6). The switching device (6) is assigned a shut-off device (5). The switching device (6) possesses a housing (60) having a pressure chamber (62), into which opens a control-air feedline (4) connected to a compressed-air source (3). Furthermore, a control-air discharge line (40) opening into the housing (60) is provided. Located in the housing (60) is a closing member (7) for the alternate connection and separation of the pressure chamber (62) and control-air discharge line (40). The feed of compressed air from the compressed-air source (3) to the compressed-air line (2) is controlled in this way. The closing member (7) is loaded in one direction of movement by the pressure effective in the pressure chamber (62) and in the opposite direction of movement by a compression spring (65). <IMAGE>

Description

The present invention relates to an open-end spinning device with a spinning rotor arranged in a rotor housing and a compressed air line connected to a compressed air source, which is arranged in a cover closing the rotor housing and is directed towards the inner surface of the spinning rotor and to which a pulsating compressed air flow can be fed.

Such a device is known from DE-2.735.311 A1. According to this known device, a pneumatic valve is arranged in the compressed air line and is controlled with the aid of an electromagnet. This electromagnet is controlled with the aid of a pulse generator, so that the cleaning air is supplied to the spinning rotor at the desired frequency. The control of the electromagnet with the desired frequency requires, on the one hand, the aforementioned pulse generator and, on the other hand, electromagnets that react extremely quickly to such pulse generators. This is relatively expensive.

The object of the present invention is therefore to create a purely pneumatic switching device. This switching device should be designed so that not only is a pulsating compressed air stream generated, but the compressed air stream should also have steep flanks, so that very sudden transitions occur from the air supply to the supply break and from the break to the new air supply.

This object is achieved in that the switching device is assigned a shut-off device and the switching device has a housing with a pressure chamber into which a control air supply line connected to the compressed air source opens, a control air discharge line opening into the housing and a closure member for alternate connection and separating the pressure chamber and control air discharge line and for controlling the supply of compressed air from the compressed air source to the compressed air line, the closure member being acted upon in one direction by the pressure acting in the pressure chamber and in the opposite direction by an elastic element. The pressure building up in the pressure chamber determines the release of the compressed air supply to the spinning rotor or the termination of this compressed air supply. If a certain pressure threshold is exceeded, the switching device releases the supply of compressed air into the spinning rotor, whereby the pressure in the pressure chamber can rapidly decrease again, so that the pressure falls below a certain minimum limit and the compressed air supply to the rotor is cut off again. The closure member can by the pressure building up in the pressure chamber either from the interruption position be brought into the cleaning position and by an elastic element from this cleaning position back to the interrupt position. However, with a corresponding configuration of the device according to the invention, it is also possible, conversely, to bring the closure member out of the interrupted position with the aid of the elastic element into the cleaning position and through the pressure building up in the pressure chamber from the cleaning position back into the interrupted position.

According to an advantageous embodiment of the subject matter of the invention, the closure member has a piston disk which delimits the pressure chamber and which can be displaced in the housing from one side of the control air discharge line to the other side thereof. In this way, the pressure chamber is alternately connected to and separated from the control air discharge line by the piston disk, whereby the pressure in the pressure chamber can be reduced by connecting the pressure chamber to the control air discharge line, causing the piston disk to return to the starting position is made possible.

The frequency with which the compressed air is fed to the spinning rotor can be controlled in different ways. According to an advantageous embodiment of the device according to the invention, a plurality of lockable control air discharge lines are arranged at different distances from the supply air line. Depending on which of these control air discharge lines is released, the piston disc must have a shorter or larger stroke distance until the compressed air accumulated in the pressure chamber can escape from the released control air discharge line. Resulting from this there are also different times and frequencies for the compressed air supply to the spinning rotor.

The compressed air escaping from the pressure chamber can be released into the atmosphere. However, it is also possible to use this compressed air for cleaning the spinning rotor, which is why, according to a further advantageous embodiment of the subject of the invention, the control air discharge line opens into the compressed air line.

According to a further advantageous embodiment of the device according to the invention, in addition to the piston disk delimiting the pressure chamber, the closure member also has a second piston disk which is arranged at a distance from the first piston disk. Such a design with two piston disks is the prerequisite for a cleaning stream to be fed to the spinning rotor in both end positions of the closure member.

According to an advantageous embodiment of the device according to the invention, the elastic element is arranged in a chamber into which the control air supply line opens, the pressure chamber being connected to the control air discharge line and through the piston disk facing away from the pressure chamber alternately with the cleaning air supply line or with a control air discharge line opening into the housing between the two piston disks can be connected. In the starting position, the chamber into which the control air supply line opens communicates with the pressure chamber. At the same time there is also the control air discharge line with the control air supply line connection. A pressure builds up in the pressure chamber until the closure member closes the connection between the control air supply line and the control air discharge line and the connection between the pressure chamber and the cleaning air discharge line and the control air discharge line is connected. Both the compressed air escaping through the control air discharge line and the compressed air escaping through the cleaning air discharge line can be used for cleaning purposes. By discharging the compressed air from the pressure chamber, the pressure drops in the latter, so that the closure member can return to the starting position. With this device, air is always discharged via the control air discharge line, while a pulsating compressed air flow is discharged through the cleaning air discharge line.

According to another alternative embodiment of the subject matter of the invention, two mutually independent lines are provided which are led through the switching device. A cleaning air supply line and a cleaning air discharge line connected to the compressed air line which opens into the rotor open into the housing and are separated from one another by the piston disc facing away from the pressure chamber, as long as the piston disc delimiting the pressure chamber separates between the control air Supply line and the control air discharge line, and which are located between the two piston disks when the piston disc delimiting the pressure chamber releases the connection between the control air supply line and the control air discharge line. In this way, a completely different vacuum can be selected for the control air than for that Spinning rotor supplied cleaning air, whereby the control frequency of the switching device can be selected independently of the pressure of the cleaning air. Advantageously, therefore, the control air supply line and the cleaning air supply line can also be subjected to different pressures.

It may be desirable if, for cleaning the spinning rotor - regardless of whether both the compressed air emerging from the control air discharge line and from the cleaning air discharge line is used for cleaning the spinning rotor, compressed air with different pressure is used. For this reason, according to an advantageous development of the device according to the invention, it is provided that the cleaning air supply line can be connected alternately to a compressed air with a high overpressure or to a compressed air supply line leading to a compressed air with a low overpressure by means of a switching device.

The frequency with which compressed air is supplied to the spinning rotor can be controlled in various ways. According to a further simple and advantageous embodiment, the distance between the two piston disks is variable for this purpose. The two piston disks can be connected to one another via a screw connection. So that the distance between the two piston disks can be adjusted relative to one another, it is advantageous that the one piston disk is assigned a rotation lock carried by the housing, while the other piston disk is connected to a rotatable adjusting element that extends sealingly in the direction of movement to outside the housing.

However, it is also possible to support the two piston disks in an axially movable manner with the interposition of an elastic element, cooperating coaxial guides being provided for mutual guidance. In this way, the relationship between the times during which a connection between the cleaning air supply line and the cleaning air discharge line or between the control air supply line and the control air discharge line is released.

As already mentioned, if separate control air and cleaning air discharge lines are provided, it is possible to feed these two air streams to the spinning rotor for cleaning. In this case, both cleaning air streams can open into one and the same compressed air line. However, it is more advantageous that if both the cleaning air discharge line and the control air discharge line are used for cleaning the spinning rotor, these two discharge lines open into two compressed air lines directed independently of one another onto the inner surface of the spinning rotor. In this way there are pulsating compressed air flows at both points of action, which practically do not interfere.

The switching device can be designed differently. According to a further advantageous embodiment, it can be provided that the pressure chamber on its side facing the control air discharge line is delimited by a wall with an opening which is surrounded by a valve seat against which the closure member can be brought into contact. To also in such an embodiment in which the closure member is not as a piston with egg ner sliding seal needs to be designed to increase the switching times, the closure member expediently has a chamber-like recess on its side facing the opening. It is advantageous if the cross section of the opening is smaller than the cross section of the chamber-like recess in the closure member, since then a pressure equalization between the pressure chamber and the chamber-like recess in the closure member is only delayed. In order to be able to adapt the size of the chamber-like recess to the desired purpose, an insert which can be inserted into the chamber-like recess is advantageously provided. This insert can be exchangeable or axially adjustable within the chamber-like recess. It is also advantageous if the cross section of the opening can also be changed with the aid of an insert.

It may be expedient if not only a pulsating compressed air flow can be fed to the spinning rotor, but alternatively if a uniform compressed air flow can also be conducted into the interior of the spinning rotor. For this purpose it can be provided in a further advantageous embodiment of the subject matter of the invention that the compressed air line can be connected to the compressed air source by bypassing the switching device via a shut-off device. Such an embodiment of the device according to the invention is particularly advantageous if the compressed air line is arranged in the cover, which also covers the rotor housing during the normal spinning process. In this case it can be advantageous to conduct a relatively weak stream of compressed air into the interior of the spinning rotor even after the rotor cleaning has been carried out. With such a training According to a further advantageous embodiment of the subject matter of the invention, the open-end spinning device is expediently provided if a first compressed air supply line carrying compressed air with high overpressure and a second compressed air line carrying compressed air with lower overpressure are provided, the compressed air line via the shut-off device with the compressed air with less overpressure leading compressed air supply line connected.

So that either a compressed air stream of high overpressure and a compressed air stream of lower overpressure can be available, it can further be provided that the shut-off device is preceded by a switching device through which the compressed air line alternately leads to the compressed air with high overpressure or to the compressed air with lower overpressure - Supply line can be connected.

The frequency of the cleaning air flow depends on the one hand on the dimension of the pressure chamber and / or the chamber-like recess in the closure member. On the other hand, this frequency also depends on the pressure of the control air. In order to be able to easily switch the control frequency at least between two stages without any changes or adjustments, it is advantageous if the control air supply line and / or the cleaning air supply line alternately to compressed air with a high overpressure or compressed air via a switching device Compressed air supply line leading to a lower excess pressure can be connected.

To ensure that the switching device regardless of the fill degree of the pressure chamber can always assume a defined basic position when the control air supply to the pressure chamber is interrupted, it is advantageous if the control air supply line can be alternately connected to a compressed air supply line or to the atmosphere via a switching device. In this way, when the control air supply line is not connected to the compressed air supply line, the pressure chamber is always emptied.

The shut-off and / or possibly provided switching device is advantageously assigned an electromagnet as a drive. Since this only requires a connection to be made or interrupted without this electromagnet also being used to generate a pulsating compressed air stream, this control device is very simple.

According to an advantageous embodiment of the subject matter of the invention, the cover can be part of a maintenance device which can be moved along a multiplicity of similar open-end spinning devices and which carries a control device with which the electromagnet or the electromagnets of an open-end spinning device is or are connected in terms of control, at least during the maintenance of this spinning device . Alternatively, it can also be provided that the cover is part of the open-end spinning device and the electromagnet or the electromagnets of an open-end spinning device is or are connected to a control device in terms of control.

In the latter case, too, it can be provided that the open end Spinning device a maintenance device can be moved along a plurality of similar open-end spinning devices and the at least one electromagnet of each open-end spinning device can be controlled by the maintenance device. Furthermore, it can be provided that one or possibly also several electromagnets can be controlled either by the maintenance device or by a control device independent of the maintenance device.

Another setting option for the frequency of the cleaning air flow is obtained when the elastic element is adjustable. In principle, this can be designed differently, but it is particularly advantageous to design the elastic element as a compression spring.

In its various forms, the subject matter of the invention enables a pulsating cleaning air flow to be generated purely pneumatically, it even being possible to preset the frequency of this air flow. Electrical pulse generators and extremely quick electromagnets are therefore not required. In this way, if such a switching device is provided at the individual spinning station, it is also possible to set the individual spinning stations differently, which means that they can be adapted to different materials that are spun at the individual spinning stations, as well as different rotors (shape, running time). is possible. In this way, optimal rotor cleaning is always guaranteed. If such a cleaning device is provided per spinning station, cleaning can also be initiated by hand. On the other hand, it is possible to additionally or al Alternatively, to provide the cleaning device on a maintenance device that runs along a machine with a plurality of open-end spinning devices. This is a particularly inexpensive solution.

• Figur 1 im Schema eine erste Ausbildung einer Vorrichtung gemäß der vorliegenden Erfindung, bei welcher die Steuerluft gleichzeitig als Reinigungsluft dient;
• Figur 2 im Querschnitt eine Schaltvorrichtung, bei welcher die Druckfeder-Beaufschlagung des Verschlußorganes einstellbar ist;
• Figur 3 im Querschnitt eine Abwandlung der in Figur 2 gezeigten Vorrichtung mit mehreren Einstellmöglichkeiten für die Beeinflussung der Schaltfrequenz;
• Figur 4 im Schema eine Ausbildung der erfindungsgemäßen Schaltvorrichtung mit zwei Kolbenscheiben und mehreren Steuerluft-Abführleitungen;
• Figur 5 im Schema eine Abwandlung der erfindungsgemäßen Vorrichtung mit mehreren, in das Rotorinnere ge­führten Druckluftleitungen und mit zwei unter unterschiedlichem Druck stehenden Druckluft-Zu­führleitungen;
• Figur 6 eine Abwandlung der in Figur 5 gezeigten Vorrich­tung im Schema; und
• Figur 7 im schematischen Querschnitt eine andere Ausbildung einer Schaltvorrichtung mit zwei Kolbenscheiben.

Several exemplary embodiments are explained in more detail below with reference to drawings. Show it:

• Figure 1 in the diagram a first embodiment of a device according to the present invention, in which the control air serves simultaneously as cleaning air;
• Figure 2 in cross section a switching device in which the compression spring loading of the closure member is adjustable;
• FIG. 3 shows in cross section a modification of the device shown in FIG. 2 with several setting options for influencing the switching frequency;
• Figure 4 in the diagram an embodiment of the switching device according to the invention with two piston disks and several control air discharge lines;
• FIG. 5 shows a modification of the device according to the invention with several compressed air lines led into the rotor interior and with two compressed air supply lines under different pressure;
• FIG. 6 shows a modification of the device shown in FIG. 5 in the diagram; and
• Figure 7 in schematic cross section another embodiment of a switching device with two piston disks.

The basic principle is first explained with the aid of the device shown in FIG. 1, all details which are not necessary for understanding the invention being omitted from the illustration.

1 shows, from a spinning station - of which a large number are usually arranged next to one another in a spinning machine - a spinning rotor 1 which is rotatably mounted in a rotor housing 10 and which is connected in a conventional manner to a suction channel 11 for generating a spinning vacuum.

The rotor housing 10 is closed by a cover 12, which carries a fiber feed channel in the usual and therefore not shown manner, through which fibers can be guided into the interior of the spinning rotor 1. In addition, the cover 12 also carries, in a manner not shown, a thread take-off channel, through which a thread produced by the binding of the fibers can be drawn out again from the inside of the spinning rotor 1.

A compressed air line 2 is arranged in the cover 12, through which compressed air can be supplied to the spinning rotor 1.

The cover 12 can be formed by the usual rotor lid, which covers the spinning chamber 10 during the spinning process. In this case, the compressed air line 2 is arranged in the cover 12 in addition to the fiber feed channel mentioned and the exhaust pipe. However, the cover can also be part of a maintenance device, not shown, which can be moved along the spinning machine and which, instead of the normal rotor lid, closes the respectively serviced rotor housing 10 during rotor cleaning.

The compressed air line 2 opens in a manner known per se in the tangential direction - shown coaxially in FIG. 1 only for reasons of illustration - against the inner wall of the spinning rotor 1.

To generate the compressed air required for cleaning the spinning rotor 1, a compressed air source 3 is provided, to which a compressed air supply line 30 is connected. As shown in FIG. 1, in spinning machines with a multiplicity of spinning stations arranged side by side, each with a spinning rotor 1, the compressed air supply line 30 extends over a multiplicity of spinning stations, a control air supply line 4 branching off from this compressed air supply line 30 for each spinning station. In this control air supply line, a shut-off device 5 is provided, which is followed by a switching device 6.

The switching device 6 has a housing 60 in the form of a cylinder, into which the control air supply line 4 opens at one end - in the end face or in the lateral surface. In the housing 60, a closure member 7 is axially movable ge leads, which has a piston rod 610 which is sealingly led out of the housing 60 through the end face 609 of the housing 60 on the end facing away from the mouth of the control air supply line 4. The piston rod 610 carries a piston disc 611 on its end facing the mouth of the supply air supply line 4. The piston disc 611 is acted upon by a compression spring 65 which surrounds the piston rod 610. To limit the stroke of the piston 61 in the direction of the housing end into which the control air supply line 4 opens, an annular stop 600 is provided in the housing 60 between this opening of the control air supply line 4 and the piston disc 611.

The piston disk 611 delimits a pressure chamber 62 which is in constant connection with the mouth of the control air supply line 4 and which changes its size by moving the closure member 7.

On the side facing away from the pressure chamber 62 of the piston disc 611 abutting the stop 600, a control air discharge line 40 opens into the interior of the housing 60 and in the exemplary embodiment shown merges into the compressed air line 2.

The arrangement of the mouth of the control air discharge line 40 and the characteristic values of the compression spring 65 are selected such that the piston disc 611 is lifted from the stop 600 by the pressure building up in the pressure chamber 62 and extends over the mouth of the control air discharge line 40 to the other Side can be moved.

During normal spinning operation, the shut-off device 5 assigned to the switching device 6 is closed, so that no compressed air can get into the pressure chamber 62 of the housing 60 of the switching device 6. Thus, no cleaning air passes through the control air discharge line 40 and the compressed air line 2 into the spinning rotor 1. If the spinning rotor 1 is now to be cleaned after the spinning station has been stopped, the shut-off device 5 is actuated so that the inflow of compressed air into the interior of the pressure chamber 62 enables. The pressure in the pressure chamber 62 thus rises and pushes the piston 61 ever further against the action of the compression spring 65 in the direction of the mouth of the control air discharge line 40. The pressure chamber 62 increases more and more until finally the piston disc 611 via the mouth of the control air Discharge line 40 is moved away. This creates a direct connection between the pressure chamber 62 and the control air discharge line 40 and thus also the compressed air line 2. The compressed air can now escape from the pressure chamber 62 via the control air discharge line 40 and the compressed air line 2 and reaches the interior of the spinning rotor 1 in the form of a compressed air pulse. The compressed air is released suddenly, so that the pressure increase in the spinning rotor 1 forms a steep flank . Finally, when the pressure in the pressure chamber 62 has decreased so far that the piston disc 611 is moved again by the compression spring 65 in the direction of the control air supply line 4, the control air is passed over by the piston disc 611 again by the control air discharge line 40 -Delivery line 40 separated from the pressure chamber 62 and the supply of compressed air to the spinning rotor 1 is suddenly interrupted again, so that a steep pressure drop flank also arises here.

These steep pressure build-up or pressure drop flanks result in a very intensive impact of the compressed air blasts on the inner wall of the spinning rotor 1 and thus also a very intensive cleaning of this spinning rotor 1.

The switching device 6 can be designed differently. Thus, the housing 60 does not necessarily have to be cylindrical. The switching element, which is designed as a piston 61 according to FIG. 1, can also have different shapes. Thus, the housing 60 of the switching device 6 shown in FIG. 2 has a pressure chamber 620, which is separated from a further chamber 64 by an intermediate wall 63 on its side facing the control air discharge line 40. The chamber 64 receives the closure member 7, which is acted upon by the compression spring 65 on its side facing away from the intermediate wall 63.

The intermediate wall 63 has an opening 630 which is surrounded on its side facing the closure member 7 by an annular valve seat 631. With this valve seat 631, the closure member 7 cooperates, which carries an annular seal 70 for this purpose. A space 640 is formed within the valve seat 631 between the intermediate wall 63 and the closure member 7.

The end face 601 of the pressure chamber 620 opposite the intermediate wall 63 carries a guide pin 602 which extends into a blind hole 71 of the closure member 7 facing the guide pin 602. The guide pin 602 and the blind bore 71 have dimensions such that regardless of the respective Ar beit position of the closure member 7 this is always safely guided by the guide pin 602.

The closure member 7 has a chamber-like recess 72 on its side facing the pressure chamber 620 and thus the opening 630.

Fig. 2 shows the switching device 6 in its closed position, in which the closure member 7 sits with its ring seal 70 on the valve seat 631 and thus separates the pressure chamber 620 from the chamber 64. If the pressure in the pressure chamber 620 rises when the shut-off device 5 is opened, the compressed air flows from the pressure chamber 620 through the opening 630 in the intermediate wall 63 into the space 640 between the intermediate wall 63 and the closure member 7. In addition, the compressed air also passes in the chamber-like recess 72 in the closure member 7. Finally, when the pressure in the space 640 and in the chamber-like recess 72 reaches a value which exceeds the force exerted by the compression spring 65, the closure member 7 with its ring seal 70 is lifted off the valve seat 631 , wherein the closure member 7 is securely guided by the guide pin 602. The compressed air can now escape from the space 640 and the chamber-like recess 72 into the chamber 64 and from there it passes into the control air discharge line 40 and into the compressed air line 2, from where it is guided against the inner wall of the spinning rotor 1. As a result, the closure member 7 again comes into contact with the valve seat 631.

In the embodiment shown, the cross section is Opening 630 is significantly smaller than the inside diameter of valve seat 631 and than the cross section of chamber-like recess 72. Thus, opening 630 has a throttling effect, ie the pressure in chamber 640 and in chamber-like recess 72 builds up delayed compared to the pressure in pressure chamber 620 . This results in a reduced switching frequency compared to an embodiment in which the opening 630 is larger than shown.

The switching frequency is also essentially determined by the size ratio of the pressure chamber 620 with respect to the chamber-like recess 72 and the space 640. The smaller the total space formed by the space 640 and the chamber-like recess 72 - which may also be omitted - compared to the pressure chamber 620, the quicker pressure equalization is achieved here, in particular if the cross section of the opening 630 in relation to the space 640 and the chamber-like recess 72 is large. If, on the other hand, this total space formed from the space 640 and the chamber-like recess 72 is large in comparison to the pressure chamber 620 and, furthermore, the cross section of the opening 630 is relatively small, it takes a little longer until a pressure equalization between the pressure chamber 620 and that through the space 640 and the chamber-like recess 72 formed total space takes place, so that it then takes longer until the closure member 7 is lifted from the valve seat 631.

A further influence on the switching frequency of the switching device 6 is also achieved by the prestressing of the compression spring 65. For this reason, according to FIG. 2, the housing 60 has on its end face 603 facing away from the end face 601, a threaded bore 604, into which a spring tension screw 650 is inserted, which receives the end of the compression spring 65 facing away from the closure member 7. The pretension of the compression spring 65 can thus be changed by adjusting this spring tension screw 650. The greater the preload of the compression spring 75, the longer it takes until the pressure building up in the pressure chamber 620 can overcome the spring force. While this is faster when the spring force is smaller.

In the device described above, too, the compressed air, after release of the shut-off device 5, passes through the control air supply line 4 into the pressure chamber 620 and from there into the control air discharge line 40. As mentioned, the switching frequency depends on the dimensions of the pressure chamber 620, the room 640, the chamber-like recess 72 and their relations, from the spring force and from the bias of the compression spring 65.

Also in the embodiment shown in Fig. 2, the air suddenly escapes from the total space formed by the space 640 and the chamber-like recess 72 between the valve seat 631 and the ring seal 70 into the chamber 64, so that the closure member 7 then returns to it Close position occurs very suddenly. The blasts of compressed air which leave the control air discharge line 40 are, however, not as sharply contoured as in the embodiment according to FIG. 1, since the chamber 64, which inevitably accommodates the closure member 7, causes damping.

FIG. 3 shows a modification of the device shown in FIG. 2, which shows additional setting options for the switching frequency of the switching device 6.

In this embodiment shown in FIG. 3, the housing 60 has a cylindrical shape, since such a configuration enables steeper pressure rise and fall edges. This is due to the fact that the closure member 7 can be designed as a (sealing or largely sealing) piston which completely or substantially seals off the size of the space created by its stroke between the intermediate wall 63 and the closure member 7 with respect to the chamber 64.

In the exemplary embodiment shown, the control air supply line 4 opens axially through the end wall 601 into the pressure chamber 620. In this embodiment, an insert 632 is located in the intermediate wall 63 between the pressure chamber 620 and the chamber 64 and can be screwed into a threaded hole 633 in the intermediate wall 63. This insert 632 has the opening 630 previously mentioned in the discussion of FIG. 2 and has a slot 634 in one of its end faces, into which a tool, e.g. is similar to screwing, can intervene.

In the embodiment of the switching device 6 shown in FIG. 3, the housing 60 is formed in two parts and consists of a first housing part 605, into which the control air supply line 4 opens and which receives the pressure chamber 620, and a housing part 606, which includes the chamber 604 the intermediate wall 63 receives. The two housing parts 605 and 606 are Connected to one another in a conventional manner, a sealing disk 607 being located between the housing parts 605 and 606. It is thus possible, after detaching the housing part 605 from the housing part 606, to make the insert 632 accessible and to set it.

As FIG. 3 shows, however, it is also possible to form the end face of the housing 60 facing away from the pressure chamber 620 by means of the correspondingly dimensioned spring tensioning screw 650, which is screwed onto a thread 653 on the outside of the housing 60. In this way, after unscrewing the spring tensioning screw 650, the closure member 7 can also be removed from the housing 60, so that the insert 632 is also accessible from the side facing away from the pressure chamber 620. In this case, it is unnecessary to form the housing 60 in two parts.

The insert 632 can be exchanged for another insert whose opening 630 has a different inner diameter. As a result, the cross section of the opening 630 and thus also the speed at which a pressure equalization is established between the pressure prevailing in the pressure chamber 620 and the pressure which arises in the total space consisting of the space 640 and the chamber-like recess 72 can be influenced. The size of the space 640 can also be changed compared to the pressure chamber 620 by axially adjusting the insert 632 in the intermediate wall 63.

That the bias of the compression spring 65 can be changed by adjusting the spring tensioning screw 650 accordingly, whereby the switching frequency of the switching device 6 can also be influenced, has already been mentioned above. As shown in FIG. 6, a spring tensioning screw 650 adapted to the respective construction of the switching device 6 can basically be provided for presetting the tension of the compression spring 65.

Fig. 2 shows an additional way of influencing the switching frequency. In this embodiment, the chamber-like recess 72 of the closure member 7 is delimited radially outwards by a thread 720 into which a disk-like insert 721 is screwed. Here, too, there is the possibility of accomplishing the relative position of the insert 721 with respect to the closure member 7 from the side of the closure member 7 facing the intermediate wall 63.

According to FIG. 3, the insert 721 is arranged at the end of an adjusting bolt 722, which extends sealingly through the closure member 7 and through the spring tension screw 650 or, if one is not provided, through the end face 603 of the housing 60 of the switching device 6. For this reason, a corresponding seal 700 is provided in the closure member 7, while the end face 603 of the housing or the spring tensioning screw 650, which carries a seal 651 on its outer circumference, also carries a seal 652 inwards for sealing against the adjusting bolt 722. The adjusting bolt 722 extends to the outside of the housing 60 and there has a tool engagement surface 723 in the form of an outer or inner profile, for example a slot. With such a design, the size of the chamber-like recess 72 can be axially Adjust the insert 721 from the outside without opening the housing 60 and thus also the switching frequency of the switching device 6.

In the exemplary embodiments of the switching device 6 described above, a control air supply line 4 was always provided, which can be connected to a control air discharge line 40, this control air discharge line 40 merging into the compressed air line 2, which ends in the interior of the spinning rotor 1. Another embodiment is described with the aid of FIG. 4, according to which the control air supply line 4 and the control air discharge line 40 serve to control the switching device 6 and not - or at most as an additional measure - to clean the spinning rotor 1. For cleaning the spinning rotor 1, a cleaning air supply line 8 and a cleaning air discharge line 80 are provided, which are passed through the housing 60 in a way that is separate from the control air flow.

Both the control air supply line 4 and the cleaning air supply line 8 two conditions from the compressed air supply line 30 mentioned in connection with FIG. 1. In contrast to the control air supply line 4, there is no shut-off device 5 in the cleaning air supply line 8, since the compressed air supply to the spinning rotor 1 is controlled by means of the controllable switching device 6 and requires no additional control. The cleaning air discharge line 80 opens into the compressed air line 2.

As shown in Fig. 4, the closure member 7 consists of the pressure Chamber 62 delimiting piston disc 611 and a piston 613 connected to it via a piston rod 612, which is acted upon by the compression spring 65 on its side facing away from the piston disc 611. The piston disc 611 and the piston 613 can also merge into one another without there being a reduction in diameter between these two parts.

In the basic position, in which there is no overpressure in the pressure chamber 62, the piston disk 611 is held in contact with the stop 600 of the housing 60 due to the action of the compression spring 65 and is thus located between the control air supply line 4 and the control air discharge line 40 In this position, the part of the closure member 7 forming the piston 613 covers the mouths of the cleaning air supply line 8 and the cleaning air discharge line 80 with a seal 614 or separates them from one another in another way. If the pressure in the pressure chamber 62 increases, the closure member 7 is displaced in the direction of the compression spring 65. Finally, the piston 613 with its seal 614 releases the connection between the cleaning air supply line 8 and the cleaning air discharge line 80. The mouths of the cleaning air supply line 8 and the cleaning air discharge line 80 are now between the piston 613 and the piston disc 611.

When the closure member 7 moves further in the direction of the compression spring 65, the piston disk 611 finally passes over the control air discharge line 40, thereby releasing the connection between control air supply line 4 and control air discharge line 40, whereby the pressure chamber 62 empties and the closure organ returns to its initial position due to the action of the compression spring 65, in which the piston disc 611 abuts the annular stop 600 of the housing 60. Here, the connection between the cleaning air supply line 8 and the cleaning air discharge line 80 is interrupted again. By further supplying compressed air to the pressure chamber 62, this game is repeated again.

The compression spring 65, which is arranged according to FIG. 4 between the end face 609 and the piston 613, can also be supported on an annular stop between the piston disk 611 and the piston 613 on the one hand and on the piston disk 611 on the other hand. The annular stop must, of course, be arranged such that the required travel of the closure member 7 is not impaired.

4, in addition to the control air discharge line 40 already mentioned, further control air discharge lines 41 and 42 open into the interior of the housing at different distances from the stop 600 or from the control air supply line 4. In each of the three control air discharge lines 40, 41 and 42, a shut-off device 400, 410 and 420 is arranged. Depending on which of the three control air discharge lines 40, 41, 42 is released by opening the corresponding shut-off device 400, 410 or 420, the piston disc 611 must execute a different stroke path before the pressure chamber 62 can be emptied. Thus, the connection between the cleaning air supply line 8 and the cleaning air discharge line 80 is released correspondingly longer or shorter. By opening or closing one or the other of these shut-off devices 400, 410 and 420, the switching frequency of the switching device 6 can thus be set.

Since the control air is controlled in the same way as is the case in the embodiment according to FIG. 1 and thus a pulsating compressed air flow with steep flanks at the two ends of its compressed air pulses is also generated here, this air can also be used for cleaning the Pull up spinning rotor 1. According to FIG. 4, therefore, the three control air discharge lines 40, 41 and 42 open into a common line 43, which in turn opens into the cleaning air discharge line 80 or directly into the compressed air line 2.

In the embodiment shown, however, the line 43 is neither introduced into the cleaning air discharge line 80 nor into the compressed air line 2, but opens out at another point on the inner surface of the spinning rotor 1 independently of the compressed air line 2 (FIG. 5). The two compressed air lines (compressed air line 2 and line 43) which are directed independently of one another onto the inner surface of the spinning rotor 1 offer the advantage that, on the one hand, the air flows cannot be impaired and, on the other hand, there is no air jam in the compressed air line 2 because too much air at once to be passed through this compressed air line 2.

In the device shown in FIG. 4, it is important that when the compressed air supply to the switching device 6 is shut off, the piston 613 and also the piston disk 611 into the one shown in FIG. 4 Return to the basic position. Otherwise, the compressed air supply in the spinning rotor 1, depending on the position of the closure member 7, might not be interrupted. For the above reasons, according to FIG. 4, the shut-off device 5 is not only designed as a simple shut-off valve, but rather as a switchover device which, in its switched-on position, connects the pressure chamber 62 via the control air supply line 4 to the compressed air supply line 30 and in the other position the Switching device 6 facing part of the control air supply line 4 connects to an emptying opening 50 of the shut-off device 5, which releases the compressed air into the atmosphere when released. In this way it is ensured that when compressed air is no longer to be fed into the spinning rotor 1 for cleaning purposes, the pressure chamber 62 is connected to the atmosphere, so that the pressure chamber 62 is emptied and the compression spring 65 the piston disc 611 and the piston 613 leads back to the basic position shown in FIG. 4.

It can be advantageous - especially if after switching on a fiber feed device, not shown, the fiber air flow on its way between the fiber feed device and the spinning rotor 1 is first sucked off and thereby removed and is only fed to the spinning rotor 1 for the actual piecing, even after the cleaning process an air stream is passed into the spinning rotor 1, which should then not be pulsating in nature. For such a purpose, it is provided according to FIG. 4 that the compressed air line 2 is bypassing the switching device 6 and its shut-off device 5 via a connecting line 20 with the compressed air supply line 30, in the connecting line 20 a shut-off device 21 is provided. This shut-off device 21 only releases the connection between the compressed air supply line 30 and the compressed air line 2 leading into the spinning rotor 1 or prevents this connection without causing a pulsation of the air flow, so that the fiber air flow is removed before it reaches the inside of the Spinning rotor 1 reached, is supported.

The shutoff devices 5 and 21 can in principle be controlled in any way. For example, it is possible to control these devices by hand. On the other hand, nowadays, where the spinning usually takes place automatically, it is expedient if the compressed air supply into the spinning rotor 1 can be controlled without manual intervention. According to FIG. 4, the two shut-off devices 5 and 21 are each assigned electromagnets 51 and 210 as a drive, which are in control connection with a control device 9 and can thus be actuated from the latter (see FIG. 6).

If the compressed air line 2 is arranged in a cover 12 which is formed by the rotor lid, this control device 9 can be arranged at the spinning station or centrally on the spinning machine or else on a maintenance device which can be moved along a plurality of similar spinning stations and that Spinning controls at a single spinning station. Even if the control device 9 is arranged at the spinning station or centrally on the spinning machine, this control device 9 can be connected in a superordinate or subordinate manner to a control device arranged on such a maintenance device.

However, if the cover 12 is carried by such a maintenance device (not shown), the mentioned control device 9 is also arranged on this maintenance device.

4, the connection of the line 43 to the cleaning air discharge line 80 is shown in dashed lines. If it is not desired that this air reaches the spinning rotor 1 as cleaning air, the control air discharge lines 40, 41 and 42 can also open into the atmosphere.

Another modification of the switching device 6 is shown in FIG. 5. According to this exemplary embodiment, only a single control air discharge line 40 is provided. In this exemplary embodiment, the piston disk 611 and the second piston disk of the closure member 7, which is designed as a piston 613, are not rigidly connected to one another, but are movable with respect to one another in the axial direction, so that the distance between the piston 613 and the piston disk 611 is variable. The relative position of piston 613 and piston disk 611 can be fixed after adjustment (as will be explained below with the aid of FIG. 7) or can be of an elastic nature through the interposition of an elastic element, for example a compression spring 617. In the latter case, both the piston disc 611 and the piston 613 have cooperating coaxial guides, which are designed as guide sleeves 615 and 616 and with the aid of which the piston 613 and the piston disc 611 guide one another. The two guide sleeves 615 and 616 also receive a compression spring 617, which is supported on the one hand on the piston 613 and on the other hand on the piston disc 611.

The closure member 7 consisting of piston 613 and piston disk 611 is acted upon on the one hand by the compression spring 65 and on the other hand by the pressure of the compressed air prevailing in the pressure chamber 62. In the starting position, the piston disk 611 is in contact with the annular stop 600 of the housing 60. The compression spring 617 is weaker than the compression spring 65, so that the piston 613 has approached the piston disk 611, the compression spring 617 being largely pretensioned. In the basic position shown in FIG. 5, the guide sleeve 616 is in any case still at a distance from the piston disk 611 with its free end.

If compressed air is now supplied to the pressure chamber 62 through the control air supply line 4, the weaker compression spring 617 is first compressed before the piston 613 begins to move. If the pressure in the pressure chamber 62 continues to increase, the guide sleeve 616 finally comes with its free end face to bear against the piston disk 611, so that the piston 613 is also driven by the piston disk 611, the compression spring 65 being increasingly tensioned. Finally, the connection between the cleaning air supply line 8 and the cleaning air discharge line 80 is released, and shortly thereafter the connection between the control air supply line 4 and the control air discharge line 40. The pressure chamber 62 is thus emptied. Suddenly, both compression springs 65 and 617 can relax, so that the piston disc 611 is at a greater distance from that in the piston 613. The closure member 7 consisting of piston disk 611 and piston 613 now returns to the basic position shown in FIG. 5. There is a shutoff tion of the supply of the cleaning air in the cleaning air discharge line 80 is delayed compared to the closing of the connection between the control air supply line 4 and the control air discharge line 40, so that the compressed air supply in the spinning rotor 1 is extended compared to the supply of the control air into the control air discharge line 40.

Fig. 5 shows that the compressed air source 3 can be connected to a further compressed air supply line 32, in which the overpressure is thus lower than in, in addition to the compressed air supply line 30, in which compressed air is guided at a high overpressure of the compressed air supply line 30. Both the control air supply line 4 and the cleaning air supply line 8 - or just one of these supply lines 4 and 8 - can be connected via an upstream switching device 44 or 81 with the compressed air supply line carrying the compressed air at a higher pressure 30 or connected to the compressed air supply line 32 with lower overpressure. In this way it is possible to apply a different overpressure for the control of the switching device 6 - and thus for the determination of the switching frequency - than is desired for the cleaning of the spinning rotor 1. It can also be provided that the pressure reducing device 31 is adjustable - just like the effect of the compressed air source 3, possibly via a further pressure reducing device for the control air supply line 30 - can be adjustable. In this way, the air pressures with which the control air supply line 4 and the cleaning air supply line 8 can be acted upon can be set individually to suit the particular circumstances will. In addition, such a switching device 22 can also be provided for the connecting line 20 and thus for the compressed air line 2, so that the continuous compressed air flow that can be fed to the spinning rotor 1 can optionally have a high or a lower pressure.

For the reasons explained in connection with FIG. 4, it will generally be expedient if the compressed air line 2 is connected to the compressed air supply line 32 carrying lower overpressure, which is why the switching device 22 may also be omitted.

As the above description shows, the switching device 6 and also the air supply to the switching device 6 or the air supply from the switching device 6 to the spinning rotor 1 can be designed in different ways. It is therefore possible within the scope of the present invention to exchange the features described in connection with the various configurations with one another or to replace them with equivalents or to use them in other combinations. For example, it is also possible not to design the distance between the piston disk 611 and a piston disk 68 corresponding to the piston 613 of FIGS. 3 to 5 in an elastic manner, but to make it permanently adjustable, for example by means of a screw connection. In FIG. 7, the guide sleeve 616 is provided, for example, with an internal thread 618, with which it is screwed onto a threaded bolt 619 extending from the piston disc 611 in the direction of a piston disc 68.

In order to be able to adjust the distance of the piston disks 611 and 68 from one another from outside the housing 60, an actuating element extending to the outside of the housing 60 is connected to the piston disk 68, while a rotation lock, which is carried by the housing 60, is assigned to the piston disk 611 . According to the special embodiment shown in FIG. 7, the piston disk 611 has a bore 66, through which a guide pin 660 extends as a rotation lock and is carried by the end face 608 of the housing 60 opposite the piston disk 611. The piston disc 611 carries an annular seal 661, which ensures that no air can escape through the opening 66 from the pressure chamber 62 into the chamber 69 between the piston disc 611 and 68.

An adjusting bolt 662 extends from the piston 613 as an adjusting element through the front side 609 of the housing 60 facing away from the front side 608 up to the outside thereof and carries a tool engagement surface 663 in the form of a slot or a poligonal inner or outer contour. For sealing against the adjusting bolt 662, the end face 609 of the housing 60 carries an annular seal 664.

By turning the adjusting bolt 662 in one direction or the other, the guide sleeve 616 is screwed more or less far onto the threaded bolt 619, which is prevented by the guide bolt 660 from following the rotation of the guide sleeve 16. By screwing the guide sleeve 16 onto the threaded bolt 619 to different extents, the distance between the piston disks 611 and 68 changes, which causes is that on the one hand the release of the compressed air supplied to the spinning rotor 1 takes place earlier or later accordingly. On the other hand, this also results in a change in the supply frequency of the compressed air into the spinning rotor 1, ie the switching frequency of the switching device 6.

Fig. 7 shows a further modification of the switching device 6 according to the invention, in which the control air supply line 4 takes place in a chamber 67 which also receives the compression spring 65. The piston disk 68, which delimits this chamber 67 and which effects the actual switching function, does not have to have a large linear expansion in this exemplary embodiment, since it does not have the task of a cleaning air supply line 8 and a cleaning air discharge line 80 (see, for example, FIGS. 4 and Fig. 5) to cover. In the basic position shown of the interconnected piston disks 611 and 68, the pressure chamber 62, which is located at the end of the housing 60 facing away from the chamber 67, is connected to the chamber 69 between the two piston disks 611 and 68 by a connecting line 690. In addition, in this basic position of the closure member 7 from this chamber 69, the control air discharge line 40 and - regardless of the position of the closure member 7 - the cleaning air discharge line 80, which in the manner already described either both in the spinning rotor 1 - in a single or open into two separate compressed air lines 2 or 2 and 43 - or of which only the cleaning air discharge line 80 is directed into the spinning rotor 1 via the compressed air line 2, while the control air discharge line 40 ends in the atmosphere.

The pressure chamber 62 is independent of the position of the closure member 7 in constant connection with the control air discharge line 40, while depending on the position of the closure member 7 alternately connected to the cleaning air discharge line 80 and separated from the control air supply line 4 or with the control air - Supply line 4 is connected and separated from the cleaning air discharge line 80.

As FIG. 7 clearly shows, the cross section or diameter of the chamber 67 receiving the piston disk 68 is smaller than the cross section or diameter of the pressure chamber 62 and the chamber 69.

To limit the maximum stroke, an annular stop 670 is provided between the chamber 67 and the piston disk 68.

If the control air supply line 4 is released by actuating the shut-off device 5 (see FIGS. 4 and 5), the pressure rising in the chamber 67 - together with the relaxing compression spring 65 - causes the piston disks 611 and 68 which are connected to one another Closure member 7 moves ever further against the pressure chamber 62 until finally the connection between the control air supply line 4 and the control air discharge line 40 is released. At the same time, however, the connection between the control air supply line 4 and the pressure chamber 62 is also released via the connecting line 690. The pressure prevailing in the chamber 67 can thus be both through the control air discharge line 40 and via the connector Duct line 690 abruptly in the chamber 67, so that the pressure prevailing in the pressure chamber 62 due to the difference in diameter of the loaded piston plates 611 and 68 moves the interconnected piston plates 68 and 611 back towards the compression spring 65. In this way, on the one hand, the connection between control air supply line 4 and control air discharge line 40 is prevented. On the other hand, however, the connection between the pressure chamber 62 and the cleaning air discharge line 80 is also released via the connecting line 690, so that air flows escape from both discharge lines 40 and 80, both of which - or only one of which - are fed to the spinning rotor 1 for cleaning can.

Due to the escape of compressed air through the control air discharge line 40 and the cleaning air discharge line 80, the pressure in the pressure chamber 62 drops, so that the control air still supplied to the chamber 67 displaces the piston disks 68 and 611 again in the direction of the pressure chamber 62, whereupon this game repeats itself.

As shown in FIG. 6, all shut-off devices 5, 21 and switching devices 22, 44, 81 are assigned electromagnets 51, 210, 220, 440, 810, all of which are connected to the control device 9, through which the switching device 6 or the individual Lines (compressed air line 2, line 43, connecting line 20, etc.) can be controlled as required for the rotor cleaning or for the piecing process. As already mentioned above, this control device can open the spinning machine or at the spinning station or on a maintenance device which can be moved along the machine.

It is not absolutely necessary that a compression spring 65 is always provided for the resetting of the closure member 7, but it is quite possible to use another elastic element, e.g. B. provide a hydraulic or pneumatic piston etc. instead. Just as the compression spring 65 can be adjustable, another elastic element can also be adjustable, for example by adjusting the cross section in a channel connecting two chambers of a cylinder.

The same also applies to the elastic element between the piston 613 and the piston disk 611, which is designed as a compression spring 617 according to FIG. 5.

If appropriate, provision can also be made for pulsating compressed air to be supplied to the spinning rotor 1 during the spinning operation. This air affects the fiber transport to the spinning rotor 1 and on the fiber deposit on the fiber collecting surface of the spinning rotor 1, so that effects arise in the thread produced. For the production of such a fancy yarn, however, it is necessary to precisely preset the overpressure so that this compressed air only affects the inside of the rotor, but not in the upstream (not shown) opening roller housing.

Claims (32)

1.Open-end spinning device with a spinning rotor arranged in a rotor housing and a compressed air line connected to a compressed air source, which is arranged in a cover closing the rotor housing and directed towards the inner surface of the spinning rotor and which can be supplied with a pulsating compressed air stream, characterized by a switching device (6 ) to generate the pulsating air flow, which is assigned a shut-off device (5) and which has a housing (60) with a pressure chamber (62, 620) into which a control air supply line (4) connected to the compressed air source (3) opens Control air discharge line (40) opening into the housing (60) and a closure member (7) for alternately connecting and disconnecting the pressure chamber (62, 620) and control air discharge line (40) and for controlling the supply of compressed air from the compressed air source ( 3) to the compressed air line (2), the closure member (7) in one direction of movement ng through the pressure chamber (62, 620) effective pressure and in the opposite direction of movement is acted upon by an elastic element (65). 2. Device according to claim 1, characterized in that the closure member (7) has a pressure chamber (62) delimiting piston disc (611) in the housing (60) from one side of the control air discharge line (40) to the other Side is movable. 3. Apparatus according to claim 1 or 2, characterized in that a plurality of lockable control air discharge lines (40, 41, 42) are arranged at different distances from the control air supply line (4). 4. The device according to one or more of claims 1 to 3, characterized in that the control air discharge line (40, 41, 42) opens into the compressed air line (2). 5. The device according to one or more of claims 2 to 4, characterized in that the closure member (7) in addition to the pressure chamber (62) delimiting piston disc (611) has a second piston disc (613, 68) which is at a distance from the first Piston disc (611) is arranged. 6. The device according to claim 5, characterized in that the elastic element (65) is arranged in a chamber (67) into which the control air supply line (4) opens, that the pressure chamber (62) with the control air discharge line (40 ) is connected and through the piston disc (68) facing away from the pressure chamber (68) alternately with the control air supply line (4) or with one between the two piston discs (611, 68) cleaning air discharge line (80) opening into the housing can be connected. 7. The device according to claim 5, characterized in that in the housing (60) a cleaning air supply line (8) and with the compressed air line (2) in connection cleaning air discharge line (80) open, which through which the pressure chamber (62 ) facing away from the piston disc (613) when the piston disc (611) delimiting the pressure chamber (62) is located between the control air supply line (4) and the control air discharge line (40), and which is between the two piston discs (611 , 613) when the piston disk (611) delimiting the pressure chamber (62) releases the connection between the control air supply line (4) and the control air discharge line (40). 8. The device according to claim 7, characterized in that the control air supply line (4) and the cleaning air supply line (8) can be acted on with different pressure. 9. The device according to claim 7 or 8, characterized in that the cleaning air supply line (8) via a switching device (81) alternately to a compressed air with high overpressure or to a compressed air with lower overpressure leading compressed air supply line (30, 32) can be connected. 10. The device according to one or more of claims 6 to 9, characterized in that the distance between the two piston disks (611, 613; 611, 68) is variable. 11. The device according to claim 10, characterized in that the the two piston disks (611, 613; 611, 68) are connected to each other via a screw connection (618). 12. The apparatus according to claim 11, characterized in that the one piston disc (611) is associated with a rotation lock (660) carried by the housing (60), while the other piston disc (68) with a sealing in the direction of movement to outside of the housing (60) reaching rotatable actuator (662) is connected. 13. The apparatus according to claim 10, characterized in that the two piston plates (611, 613) with the interposition of an elastic element (617) are axially movable against each other and cooperating coaxial guides (615, 616) are provided for mutual guidance. 14. The device according to one or more of claims 6 to 13, characterized in that the cleaning air discharge line (80) and the control air discharge line (40) in two independently of one another on the inner surface of the spinning rotor (1) directed compressed air lines (2, 43 ) flow into. 15. The device according to one or more of claims 1 to 5 and 7 to 14, characterized in that the pressure chamber (620) on its side facing the control air discharge line (40) bounded by a wall (63) with an opening (630) which is surrounded by a valve seat (631) against which the closure member (7) can be brought into contact. 16. The apparatus according to claim 15, characterized in that the Closing member (7) has a chamber-like recess (72) on its side facing the opening (630). 17. The apparatus according to claim 16, characterized in that the cross section of the opening (630) is smaller than the cross section of the chamber-like recess (72) in the closure member (7). 18. The apparatus of claim 16 or 17, characterized by an insert (721) insertable into the chamber-like recess (72). 19. The apparatus according to claim 18, characterized in that the insert (721) is axially adjustable within the chamber-like recess (72). 20. The device according to one or more of claims 16 to 19, characterized in that the cross section of the opening (630) can be changed with the aid of an insert (632). 21. The device according to one or more of claims 1 to 20, characterized in that the compressed air line (2) bypassing the switching device (6) via a shut-off device (21) with the compressed air source (3) can be connected. 22. The apparatus according to claim 21, with a compressed air with high overpressure and a compressed air with lower overpressure leading compressed air supply line, characterized in that the compressed air line (2) via the shut-off device (21) with the compressed air with lower overpressure leading compressed air supply line ( 32) is connected. 23. The apparatus according to claim 22, characterized in that the shut-off device (21) is connected upstream of a switching device (22) through which the compressed air line (2) alternately leading to the compressed air with high overpressure or to the compressed air supply line with lower overpressure (30, 32) can be connected. 24. The device according to one or more of claims 1 to 23, characterized in that the control air supply line (4) and / or the cleaning air supply line (8) via a switching device (44, 81) alternately to a compressed air with high overpressure or to a compressed air supply line (30, 32) leading to a compressed air with a lower overpressure. 25. The device according to one or more of claims 5 to 24, characterized in that the control air supply line (4) via a switching device (5, 50) alternately with a compressed air supply line (30, 32) or with the atmosphere. 26. The device according to one or more of claims 1 to 25, characterized in that the shut-off and / or possibly provided switching device (5, 50, 21, 22, 44, 81) an electromagnet (51, 210, 720, 440 , 810) is assigned as the drive. 27. The apparatus according to claim 26, characterized in that the cover (12) is part of a maintenance device which can be moved along a plurality of similar open-end spinning devices and which carries a control device (9) with which the at least one electromagnet (51, 21, 220, 440, 810) of an open-end spinning device is connected in terms of control at least during the maintenance of this spinning device. 28. The apparatus according to claim 26, characterized in that the cover (12) is part of the open-end spinning device and the at least one electromagnet (51, 21, 220, 440, 810) of an open-end spinning device with a control device (9) in terms of control Connection is established. 29. The device according to claim 28, characterized in that the open-end spinning device is a movable along a plurality of similar open-end spinning devices serviceable and the at least one electromagnet (51, 21, 220, 440, 810) of each open-end spinning device by the Maintenance device is controllable. 30. The device according to claim 28 or 29, characterized in that one or more electromagnets (51, 21, 220, 440, 810) can be controlled either by the maintenance device or by a control device (9) independent of the maintenance device. 31. The device according to one or more of claims 1 to 30, characterized in that the elastic element (65, 617) is adjustable. 32. Device according to one or more of claims 1 to 31, characterized in that the elastic element is designed as a compression spring (65, 617).

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