EP0226582A1 - Process and device for thread joining on an open-end spinning device. - Google Patents

Abstract

In preparation for the process of joining the fibers, an underpressure is applied outside the fiber transport path on the periphery of a covered cylinder (11), the underpressure being greater than the under pressure. -spinning pressure at the opening (130) of the feed passage (13) for the pick-up surface of the fiber (33). In this way, the passage of the fiber over the opening (130) is deflected and sucked. At the start of the fiber bonding process, this underpressure is removed so that the passage of the fiber is directed to the fiber uptake surface (33). To vary the passage of the fiber, a source of underpressure (5) can be connected to the suction opening (52) using a switching system (64) and a line pressure switch (51).

Description

 Method and device for piecing an open-end spinning device

The present invention relates to a method for spinning on an open-end spinning device with a feed device for feeding fiber sliver and a dissolving roller arranged in a housing, from which the individual fibers are fed via a feed channel to a fiber collecting surface for thread formation by means of suction air flow, and in which a thread end during spinning is returned to the fiber collecting surface, from which the previously returned thread is then drawn off again with continuous incorporation of fibers, the feed device being switched on in preparation for piecing and the fiber stream being deflected on its way to the fiber collecting surface while the feeding device is running and being fed to a suction device, and an apparatus for performing this method.

In the event of a thread break or after the spinning process has come to a standstill in another way, the feed device is shut down immediately in order to prevent unnecessary fiber supply which clogs and damages the spinning device. However, the opening roller generally continues to run, since stopping it separately, in particular for each spinning station, not only requires a great deal of technical effort, but also takes a long time to start up and run down. The result of this is that the fiber beard protruding from the shutdown feed device into the region of the opening roller is completely removed. Before restarting, these fiber remnants must first be removed from the fiber collection surface because these shortened and thus damaged fibers usually do not guarantee that the spinning process will continue properly (CH-PS 526.646). It is therefore known from the practice of manual spinning and breaking of the thread that the spinner first starts the feed device for a short time, then cleans the spinning device and only then starts to attach the thread. This so-called starter removes the damaged part of the beard with the shortened fibers. The subsequent stoppage of the feed device during cleaning in turn damages a considerable part of the fibers, but sufficient fibers remain in the fiber beard for successful piecing. Due to the standstill of the feed device, which is dependent on the time for cleaning, approximately the same piecing conditions were always created with respect to the fiber beard, so that the success rate in threading was considerably improved even at high rotor speeds and difficult materials.

Based on the knowledge that each standstill of the feed device causes a certain damage to the fiber beard, depending on the length of the standstill, it has also been proposed to deflect the fiber stream on its way to the fiber collection surface while the feed device is running and to lead past the fiber collection surface i a suction . For this purpose, suction openings (GB-PS 1.170.869) or compressed air openings (DE-PS 3.104. ^) Are provided in the feed channel. Due to the uninterrupted fiber feeding and dissolving process, undamaged fibers are fed to the fiber collecting surface exactly at the desired time, but the spinning process is disrupted by such openings in the very sensitive fiber transport path between the opening roller and the fiber collecting surface. Therefore none of these suggestions has gained practical importance.

The object of the present invention is to create a method and a device for spinning on an open-end spinning device, which enables perfect and safe spinning without impairing the subsequent spinning process. This object is achieved in that for the preparation of the piecing process outside the fiber transport path on the circumference of the opening roller, a vacuum is brought to effect, which is greater than the effective vacuum at the mouth of the feed channel, so that the fiber stream passes over the mouth of the feed channel and is suctioned off, and that at the beginning of the actual piecing process this negative pressure is deactivated so that the fiber stream is fed to the fiber collecting surface. All control and switching devices for the fiber stream are arranged outside the critical fiber transport path between the Auflösewa ze and the fiber collecting surface, so that an effective deflection of the fiber flow past the fiber collecting surface is achieved in a suction for piecing, without affecting the subsequent spinning process.

Advantageously, the preparation of the piecing process of the spinning vacuum at the mouth of the feed channel is reduced in its effect so that the fibers are guided over it, while at the start of the actual piecing process the vacuum outside the fiber transport path on the circumference of the opening roller is deactivated and instead the spinning vacuum at the mouth of the feed channel is brought back to its full effect. In this way, a relatively weak vacuum is sufficient to control the fiber flow on the circumference of the opening roller. In order to reduce the effect of the spinning vacuum at the mouth of the channel, the spinning vacuum is advantageously switched off.

In an alternative embodiment of the method according to the invention, in order to reduce the effect of the spinning negative pressure at the feed channel mouth, this is at least partially covered. The fibers guided over the released part of the feed channel mouth reach the feed channel and thus the fiber collecting area. In addition, part of the fibers guided over the covered area of the feed channel mouth is deflected and also reaches the feed channel, while a further part of the fibers covered over it Due to the inertia, fibers guided in the area of the feed channel mouth do not follow this change of direction and are sucked off by the negative pressure on the circumference of the opening roller after the feed channel mouth.

To achieve unobtrusive piecing, it is advantageous if, at the start of the actual piecing process, the effect of the negative pressure outside the fiber transport path on the circumference of the opening roller is reduced in its effect over a period of time or the effect of the spinning negative pressure at the mouth of the feed channel is increased again that the fiber stream gradually reaches its full strength in the feed channel. The increase in the fiber flow expediently takes place as a function of the increase in the thread take-off speed in order to avoid a change in the ≠ ^' yarn number in this spinning phase. It can do so. be proceeded so that when spinning on, only a small proportion of the fiber is initially fed to the fiber collecting surface, while at the same time the remaining fibers are passed over the mouth of the feed channel, then the end of the thread is returned to the fiber collecting surface and that after the fibers on the fiber collecting surface have been integrated, the The proportion of fibers fed to the fiber collecting surface is increased. As a result, synchronization with the thread return and thread take-off on the one hand and the fiber feed on the other hand is achieved in a simple manner.

The build-up of the fiber accumulation required for piecing takes place with a low fiber delivery rate, so that in the time from the subsequent threading to the incorporation of the pre-fed fibers, not very much fibers can be deposited on the pre-fed fibers. This results in a relatively inconspicuous thread section after the piecing without having to accept a thin spot.

Appropriately, in order to achieve unobtrusive piecing with high strength, the procedure is such that, in preparation for piecing, the fiber stream initially passes over the mouth of the feed channel the fiber stream is then briefly fed to the fiber collecting surface, then again led over the mouth of the feed channel and that the fiber stream is only fed back to the fiber collecting surface after the end of the thread has reached the fiber collecting surface and thread withdrawal has begun.

To control the fiber flow, it can also be provided according to the invention that a vacuum flow is generated in preparation for piecing s on the circumference of the opening roller in such a way that with unchanged spinning vacuum there is an at least partial reversal of the air flow in the feed channel and the air flow thus generated is on its way out the feed channel in the suction provided on the periphery of the opening roller at least partially takes away the fibers transported by the opening roller. In order that this does not require excessively high values for the vacuum in the suction, a further embodiment of a method of this type can provide that other air flows into the opening roller housing be switched off in order to reverse the air flow in the feed channel. Advantageously, for the gradual diversion of the fiber stream onto the fiber collecting surface, the other supply air flows are then switched on again in a controlled manner in order to be able to control the amount of fibers supplied to the fiber collecting surface.

Since after the piecing has taken place, the negative pressure outside the fiber transport port path at the circumference of the opening roller at the suction provided there is no longer required, this negative pressure is expediently switched off after the piecing process has ended.

So that fibers do not get onto the fiber collecting surface unintentionally when removing a thread breakage, in a further embodiment of the method according to the invention it is advantageously provided that when a thread breakage occurs, the feed device is stopped and the feed device is switched on again after cleaning the fiber collecting surface, but the fiber stream is led over the mouth of the feed channel. By stopping the fiber feed to the opening roller it is achieved that the opening roller continues the the fiber beard of the sliver clamped in the feed device is milled off into its working area. The fibers fed to the fiber collecting surface by the still acting negative vacuum are pneumatically discharged through this suction air. After this cleaning phase, the feed device is switched on again, but the fiber stream is led over the feed channel mouth, so that the fibers damaged by the milling do not reach the fiber collecting surface, but are removed from the opening roller housing.

In order to achieve safe piecing of high quality in a simple manner in rotor spinning, it is advantageously provided according to the invention that, for the preparation of the piecing process, the spinning vacuum in the rotor housing is first effective, the thread end is fed into the spinning device without touching the fiber collecting surface, and that then the spinning vacuum is switched off and the vacuum outside of the fiber transport path is brought into effect at the circumference of the opening roller, so that when the feed device is switched on again, the fiber stream is guided over the feed channel mouth and sucked off, and that this vacuum is switched off at the start of the actual piecing process the spinning vacuum is switched on so that the fiber stream is fed to the fiber collecting surface and the thread end is returned to the fiber collecting surface.

If the opening roller is followed by a fiber transport roller, it can alternatively be provided that, in preparation for the piecing process, instead of the circumference of the opening roller, a negative pressure outside the fiber transport path is brought to the periphery of this fiber transport roller.

To carry out the method according to the invention, in a device with a vacuum source, which generates a suction air flow for fiber transport through the feed channel to the collecting surface, and a suction opening in the peripheral wall of the opening roller housing outside the fiber transport path, it is provided that the vacuum source can be connected to the suction opening via a switchover device and a vacuum line. This ensures that no fibers damaged by milling get into the spinning unit, so that the fibers forming the piecer contribute fully to the strength of the piecer.

According to an advantageous embodiment of the invention, the negative pressure source is alternately assigned to the fiber collecting surface as spinning negative pressure or the suction opening for suctioning off the fibers via the switching device. As a result, the switching of the negative pressure for removing the fibers from the roller housing so that the fibers do not get into the spinning unit or for feeding the fibers into the spinning unit can be adapted exactly to the requirements of piecing.

Preferably, in an intermediate position of the switching device, both the fiber seed surface and the suction opening can be subjected to negative pressure at the same time. In this way, the fiber feed can be controlled and, through the type of switching movement (uniform, non-uniformly accelerated or decelerated movement, etc.), an exact adaptation of the switching of the vacuum conditions to the piecing process can be achieved in accordance with the fiber material to be processed and the selected spinning conditions.

Yarn and fiber residues must not accumulate in the switching device during suction. For this reason, the fiber stream in the switching device should not be deflected. For this purpose, the switching device according to a further embodiment of the invention has two control bores, one of which can be brought into alignment with the first vacuum line leading to the fiber collecting surface and the other can be brought into alignment with the second vacuum line leading to the suction opening.

In order not to impair the func tional safety of the switching process, it should be avoided that yarn and fiber residues can be trapped in the air control device. To this end can be provided according to the invention that the stationary edges and the movable edges of the switching device that can be brought into alignment with them are designed as cutting devices.

In order to facilitate the switching of the fiber stream, it is provided in a further embodiment of the subject matter of the invention that the opening roller housing is closed against incoming air flows. As a result, there are no uncontrolled air flows influencing the spinning process in the opening roller housing. If a sufficiently strong negative pressure is thus applied to the suction opening provided in the peripheral wall of the opening roller housing, a reversal of the air flow is effected with the spinning negative pressure unchanged in the feed channel. As a result, the fibers are fed into the suction opening across the feed channel mouth. ^{rf "Thus,} the fiber flow is not controlled by the height of the abutting DER suction negative pressure must w ill, has expediently the opening roller housing a controllable air inlet opening on which is preferably angeordent in the peripheral wall of the opener roller housing between the feed device and feed channel mouth.

If a dirt separation opening is provided in the opening roller housing, it is expedient to design the dirt separation opening as a controllable supply air opening.

In modern open-end spinning machines, piecing is usually carried out with the help of a maintenance carriage that can be moved along several spinning devices. In this case, it is expediently provided that the supply air flow can be controlled from this maintenance car.

In an advantageous embodiment of the subject matter of the invention it can be provided that the supply air flow is assigned a closure member designed as a flap. Such a flap-like closure member can be easily moved into another position by pivoting and can also be controlled by the air itself. In order to switch the fiber flow also quantitatively To be able to control, it can further be provided that the supply air opening is assigned a closure member which can be moved non-uniformly by a control device.

The switching of the fiber stream does not necessarily have to be done pneumatically by controlling the air flow in the housing. Alternatively, mechanical control of the fiber stream is also possible. Thus, in a further embodiment of the subject matter of the invention it can be provided that a controllable aperture covering the opening of the feed channel is provided in the opening roller housing. This enables precise reversal of the fiber flow. It also creates the possibility of a gradual changeover of the fiber stream from the suction opening to the fiber discharge opening and thus to the spinning unit in a simple manner.

In order to exclude the accumulation of fibers in front of the closed fiber discharge opening, the closure member is advantageously arranged essentially in the extension of the peripheral wall of the opening roller housing.

So that no fibers can get stuck on the cover taking up the closed position, it is expediently overlapped at its first end, as seen in the fiber transport direction, from the circumference swand of the opening roller housing, while the second end overlaps the peripheral wall of the opening roller housing, so that - in the fiber transport direction seen - there are no protruding edges.

It has been shown that it is particularly advantageous for the gradual switching of the fiber stream if the closure member is movable parallel to the axis of the opening roller. For a gradual U sha th of the fiber stream, it can be provided that the closure member between its area which completely covers the fiber discharge opening and the area which completely releases the fiber discharge opening has a profile which controls the degree of opening. This is advantageously designed as a nose. As a result, a large cross section of the fiber discharge opening can be released, which is temporarily reduced again by the nose, until finally the full cross section of the fiber discharge opening is finally released. Alternatively, for gradual changeover, it can be provided that a control device acts on the diaphragm, which moves the diaphragm non-uniformly. Thus, the closure member can be moved from the closed position to the open position with changing speed, possibly with a standstill in an intermediate position.

It is common nowadays to control the piecing from a maintenance car, which can be moved along several spinning devices. In such a case, the switching device can be controlled from the maintenance vehicle.

The device for controlling the vacuum can be different, e.g. B. as from the maintenance device controllable fan, ausgebil det; However, it is advantageously formed by a valve, in particular as a check valve.

The switching of the vacuum conditions can in principle be carried out in any customary manner, for example with the aid of electromechanical or hydro- or pneumo-mechanical means. According to a particularly simple embodiment of the subject of the invention, the switchover is carried out mechanically, the Urπ switching device being actuated in one direction of movement by a control drive, while a spring element is provided for the resetting.

If a maintenance trolley is provided, which can optionally be delivered to any number of spinning stations, then according to the invention a second vacuum source is provided on this maintenance trolley, to which the suction opening can be connected instead of the first vacuum source. In order to make additional drive means for the switching device superfluous, the switching device can advantageously be controlled by the connecting movement of a suction air line coming from the second vacuum source to the switching device.

If the opening roller is connected downstream of a fiber transport roller, according to the invention, the suction opening can be arranged in the circumference of the wall surrounding the opening roller instead of in the wall surrounding the opening roller.

The present invention makes it possible, with the aid of a simple device, to control the fiber feed into the spinning chamber in such a way that only flawless fibers enter the spinning chamber since all control and switching devices for the fiber stream lie outside the critical fiber transport path between the opening roller and the fiber collection Surface are arranged so that an effective deflection of the fiber flow past the fiber collecting surface in a suction for piecing is achieved without affecting the subsequent spinning process. The invention even enables quantitative control of the fiber flow, so that not only the piecing takes place, but also the appearance of the piecing is improved to a considerable extent without additional facilities for the controlled drive of the feed device being required. In this way, an optimal success rate for piecing is guaranteed.

Further details are explained in more detail with reference to exemplary embodiments illustrated in the drawings. Show it :

1 shows a schematic cross section of an open-end spinning device designed according to the invention;

FIG. 2 shows a top view of a switching device according to the invention arranged on the outside of a vacuum duct; FIG. 3 shows in cross section another embodiment of a switching device according to the invention;

Figure 4 shows in section a modification of an open-end spinning device according to the invention;

FIG. 5 shows a schematic cross section of an alternative embodiment of an open-end spinning device designed according to the invention;

FIG. 6 shows a schematic top view of an opening roller housing with a switching device according to the invention;

FIG. 7 shows a schematic top view of an opening roller housing with a modified switching device;

8 to 12 show a schematic side view of another embodiment of an open-end spinning device designed according to the invention in different working phases; and

FIG. 13 shows a schematic side view of an open-end spinning device with a modified switching device.

The invention is first explained below with reference to FIG. 1, which shows a spinning position of a rotor spinning machine, but the invention can also be used with other open-end spinning machines, e.g. B. Use friction spinning machines with advantage.

Each spinning station of the rotor spinning machine shown has an opening device 1 with a opening roller 11 arranged in an opening roller housing 10. To feed a sliver 4.0, the opening device 1 is assigned a feed device 2, which in the exemplary embodiment shown consists of a driven feed roller 20 and a feed trough 21, which cooperates elastically with the feed roller 20. The circumference swand 101 of the opening roller housing 10 surrounding the opening roller 11 is shown in FIG Embodiment also provide a dirt separation opening 12. Furthermore, the opening 130 of a feed channel 13 leading to the open-end spinning device 3 is provided in the peripheral wall 101 of the opening roller housing 10.

The open-end spinning device has a spinning unit designed as a spinning rotor 30, which is enclosed by a housing 31. Coaxial to the spinning rotor 30, a thread draw-off tube 32 opens into the housing 31, through which a thread 4 can be drawn out of the spinning rotor 30. For this purpose, a pair of take-off rollers 41, 42 are provided. The thread 4 is wound on a spool 44 driven by a winding roller 43. To release a previously formed piecing return delivery a discharge magnet 45 near the thread run between the take-off rollers "41, 42 and the winding roller 43 is seen easily.

A vacuum line 50, which is connected to a vacuum source 5, is connected to the housing 31 to generate the necessary spinning vacuum. Since air can be sucked into the housing 31 through the thread take-off tube 3, the spinning vacuum acting in the housing 31 is only effective to a limited extent via the feed channel 13 also at its mouth 130. In addition to this first vacuum line 50, a second vacuum line 51 connected to the open-end Spinnvo device 3 is provided. This second vacuum line 51 ends in a suction opening 52, which - seen in the fiber transport direction (arrow 46) - is provided between the mouth 130 of the feed channel 13 and the delivery device 2 outside the fiber transport path in the peripheral wall 101 of the opening roller zengehäuses 10. This second vacuum line 51 is also connected to the vacuum source 5 via a switching device 64. In the exemplary embodiment shown, this switchover device 64 is designed as a rotary body valve. With the help of the switching device 64, the first or the second vacuum line 50, 51 can be alternately connected to the vacuum source 5, which in this way alternately forms the fiber collecting surface 33 of the spinning roto 30 as spinning vacuum or the suction opening 52 for suction the fibers 47 is assigned. For this purpose, the switching device 64 is connected to a drive device 60, which is controlled by a control device 7. The position of the switching device 64 shown by the solid line in FIG. 1 is the spinning position during which the spinning vacuum is generated in the spinning rotor 30, and the position indicated by dashed lines is the fiber removal position in which the vacuum is present at the suction opening 52 . Depending on the position which the switching device 64 occupies, the fibers 47 are thus guided into the feed channel 13 or into the suction opening 52.

Of course, a filter, not shown, is provided in the vacuum line 51 at a suitable point, with which the extracted fibers 47 are collected.

The sliver 40 to be spun is fed to the opening device 1 with the aid of the feeding device 2 and is broken up into individual fibers 47 by the opening roller 11. By the opening roller 11, which causes the fiber transport from the feed device 2 to the feed channel 13, dirt components contained in the fiber material are thrown out through the dirt separation opening 12. The fibers 47, on the other hand, enter the spinning rotor 30 and are deposited there on the fiber collecting surface 33, where the fibers 47 are bound into the end of the thread 4. This thread 4 is drawn off from the spinning rotor 30 by the take-off rollers 41, 42 and wound on the spool 44. During this normal spinning process, the changeover device 64 assumes its spinning position, in which, via the first vacuum line 50, the spinning vacuum generated by the vacuum source 5 is applied to the housing 31 and to a reduced extent to the mouth 130 and the connection of the second vacuum line 51 to the vacuum source 5 is interrupted.

If a thread break occurs now, the spinning process is interrupted in a known manner via a thread monitor, not shown, and the spinning station is switched off. For this purpose, the supply of the sliver 40 to the opening roller 11 is stopped by stopping the delivery device 2 bound. However, the housing 31 remains in connection with the vacuum source 5. The spinning rotor 30 is then braked. At the same time, the fibers 47 still remaining in the spinning rotor 30 and the end of the broken thread 4 are detached from the thread-forming region 33 of the spinning rotor 30 by introducing a mechanical or pneumatic cleaning agent and are suctioned off from there.

Already during this cleaning phase or even thereafter, the thread 4 is searched for on the bobbin 44, drawn off from it, shortened to a defined length, brought to the mouth of the thread take-off tube 32, forming a thread reserve above the armature of the ejection magnet 45, and then with the aid of the also i thread take-off tube 32 of effective spinning negative pressure is introduced into the spinning rotor 3, but without touching the fiber sappel surface 33.

In order to prevent further fibers 47 from getting onto the fiber collecting surface 33 of the spinning rotor 30 after the spinning rotor 30 has been cleaned after the feed device 2 has been switched on again, the changeover device 64 is then brought into its fiber removal position in preparation for the piecing process. Then the feed device 2 is switched on again. The fiber stream is now sucked out of the opening roller housing 10 through the suction opening 52. Since the spinning rotor 30 is stopped and also on the housing 31 of the open-end spinning device 3, the spinning vacuum is switched off so that the effect of the spinning vacuum is eliminated, the suction air flow brought into effect at the suction opening 52 is sufficient to counteract the fibers 47 against the action of those caused by the rotating opening roller 11 to generate centrifugal force through the mouth 130 of the feed channel 13 to the suction opening 52. In this way it is ensured that the fibers 47, which were milled in the time from the shutdown phase by the continuous opening roller 11 and thereby shortened, cannot get into the spinning rotor 30 and reduce the strength of the piecing. During the return of the thread 4 in front of the mouth of the thread take-off tube 32, the thread end acquires a shape which is advantageous for spinning in a known manner. The switching device 64 is reversed again and brought into its spinning position so that the vacuum is switched off at the suction opening 52 and switched on in the spinning rotor 30 and at the mouth 130 of the feed channel 13.

By dropping the thread 4 from the ejection magnet 45, the thread 4 is now returned to the fiber collecting surface 33 due to the negative pressure now acting in the spinning rotor 30. The thread end comes into contact with the fibers 47 located on the fiber collecting surface 33, which in the case of the spinning rotor shown form a fiber ring. The thread 4 is then withdrawn from the spinning rotor 30 with the constant inclusion of the continuously fed fibers 47 and wound up on the spool 44.

The switching operations of the switching device 64 are carried out with the aid of a drive device 60, which receives its control commands from a control device 7. This control device 7 usually controls in addition to the switching device 64, other processes besides piecing and thread break rectification, such as. B. Reel change etc.

In order to avoid thread breaks during piecing, it is usually provided that there is no thin joint in the thread 4 at the attachment point. For this reason, there must be a quantity of fibers in the thread formation region 33 of the spinning rotor 30 which corresponds to the thread thickness at the moment of attachment. Since a thread end intended for piecing is generally not tapered, but merely opened by splicing, the piecing cross section thus has twice the fiber mass as the spun thread.

During the thread withdrawal from the Sp innrotor 30 fibers 47 are continuously fed to the fiber collecting surface 33 of the Sp innrotor 30, so that the fiber ring continues to grow and the strength of the spun thread exceeds 4. The fiber ring continues to grow until the tie-in point brought about by the take-off rollers 41, 42 with respect to the rotor circumference again reaches the starting position during attachment. Only at the moment when the fiber feed and thread take-off reach the same ratio as during production does the thread 4 have the desired nominal strength.

In order to avoid complex control devices for the feed device 2, it can usually only be switched on and off. The take-off rollers 41, 42 and the spool 44 take a longer time than the slow-running feed device 2, because of inertia, until they have reached their final production speed. It therefore always takes a certain amount of time until this synchronization ratio is reached. i A thread section with a weaker cross-section then forms after the piecer forming a thick spot, which is followed by a second thick spot. This is disruptive until further processing, especially since it is much longer than the piecing.

To avoid this second thick point, it is necessary that the fiber quantity fed into the spinning rotor 30 is adapted to the respective thread take-off speed. For this purpose, the increase in the fiber flow between the feed device 2 and the spinning rotor 30 is controlled. For this purpose, the switchover of the changeover device 64 from the fiber discharge position into the spinning position is not carried out abruptly, but gradually so that the increase in the fiber flow takes place as a function of the increase in the thread withdrawal speed. This is made possible by the fact that in an intermediate position of the switching device 64, both the fiber collecting surface 33 and the suction opening 52 are simultaneously subjected to negative pressure. In a transition phase, the negative pressure acts both in the suction opening 52 and in the housing 31 of the open-end spinning device 3, so that the fibers 47 gradually get onto the fiber collecting surface 33 of the spinning rotor 30 with an increasing delivery rate. To do this, proceed as follows:

To prepare for the piecing process, the fiber stream is first discharged through the suction opening 52, as previously described. Then the switching device 64 is initially only moved slightly out of the fiber removal position in the direction of the S ^' pinned position, so that the spinning vacuum gradually increases and the vacuum at the suction opening 52 gradually decreases. Initially, only relatively few fibers 47 thus get into the spinning rotor 30, while the remaining fibers 47 are still transported over the mouth 130 of the feed channel 13 and are removed through the suction opening 52. The switching device 64 remains in this position until the slowly building up fiber ring has reached the desired thickness desired for piecing.

Now the thread end is returned in a known manner to the fiber collecting surface 33 in the spinning rotor 30 and placed on the fiber ring, integrated there as usual and then withdrawn from the spinning rotor 30. During this time, relatively few fibers 47 enter the spinning rotor 30 despite the feed device 2 being switched on, since most of the fibers 47 are sucked into the suction opening 52. The fiber ring thus grows only slowly, so that - after a short, thinner thread section - the thick spot following the piecer is inconspicuous. The thickness of this thinner thread section is determined by the amount of fiber in the fiber ring at the time of spinning, which in turn is determined by the duration of the fiber pre-feeding. The fibers 47 which are already in the spinning rotor 30 at the time of spinning are continuously incorporated into the thread end. After this incorporation, depending on the increase in the thread draw-off, the spinning negative pressure effective in the spinning rotor 30 is increased more and more, as a result of which the proportion of fibers entering the spinning rotor 30 also increases until finally the maximum negative pressure acts on the mouth 130 of the feed channel 13 and the suction opening 52 does not more vacuum is applied so that all fibers 47 now get into the spinning rotor 30. The reduction in the effect of the negative pressure outside the fiber transport path, d. H . at the suction opening 52, and the increase in the effect of the negative pressure in the spinning rotor 30 and at the mouth 130 of the feed channel 13 take place over a longer period of time, so that the fiber stream gradually reaches its full strength in the feed channel 13.

An embodiment of the piecing device which is suitable for carrying out such a method will now be described with reference to FIGS. 1 and 2.

FIG. 2 shows the underside of a suction channel 53 which is connected to the vacuum source 5 (FIG. 1) and which - as is customary in open-end spinning machines - can be arranged via a large number of spinning stations arranged next to one another, eg. B. rotor spinning positions. For each open-end spinning device 3, a switching device 6 is provided on this suction channel 53, which has a web 54 and 55 on its longitudinal sides on its underside 61 and 62. The actuating element 61 has an elongated hole 610, with the aid of which the vacuum line 50 or 51 can be connected to the openings provided in the underside of the suction channel 53. The actuating element 61 is sealed between the underside of the suction channel 53 and a sealing strip 56 which connects the two webs 54 and 55. The elongated hole 610 has a minimum size which corresponds to that of the cross sections of the vacuum lines 50 and 51, but can also have a greater length, as will be explained below

At its end facing the operating side of the spinning machine 36 (on the right in FIG. 2), the actuating element 61 has an enlarged operating button 611. One end of a spring element 612, the other end of which is supported on the web 54, is supported on this actuating button 611. The control element 61 has at its other end a stop 613 which secures the released control element 61 in its spinning position, in which the vacuum line 50 is connected to the suction channel 53. The actuating element 61 has on its long side a locking lug 614, behind which a pawl 63 can snap into place. The pawl 63 is pivotally mounted about an axis 58 provided in the web 55 and is elastically loaded by a spring element 630. The other end of the spring element 630 is supported on a web 57 which connects the two webs 54 and 55 to one another.

The pawl 63 has at its end facing the web 54 a ramp-like slope 631, on which the bevelled end 620 of the actuating element 62 can run. The end of the actuating element 62 facing away from this bevelled end 630 has an enlarged actuating button 621. A spring element 622 is supported between this actuating button 621 and the web 54, so that the actuating element 62 is directed towards the operating side (right in FIG. 2) of the machine is acted upon. In order to limit the movement caused thereby, the actuating element 62 carries a stop 623 between the web 54 and the bevelled end 620.

The control device 7 already mentioned, which controls the entire piecing process, etc., Is arranged on a maintenance carriage 70, which can be moved along the operating side of the spinning machine 36 and can thus optionally operate any desired spinning position of a multiplicity of such spinning positions. controls. This Steuerervorrich device 7 is suitably connected in terms of control with drive bolts 71 and 72, which together with the actuating buttons 611 and 621 form a drive device 60 for the switching device 6. The drive bolts 71 and 72 can each be part of an armature of an electromagnet, for example. If the drive bolts gradually, i.e. are to be driven very gradually or during their movement phase with changing speed, this is also a drive with the aid of a stepping motor or the like. possible.

FIG. 2 shows the switchover device 6 in its fiber discharge position, since the elongated hole 610 opens the connection between the suction channel 53 and the vacuum line 51. In this position, the actuating element 61 is secured by the pawl 63, which is behind the locking nose 614 is engaged. If the changeover device 6 is now to be brought into its spinning position, the control device 7 of the maintenance device 70 uses the drive bolt 72 - or, if desired, possibly. also by hand - the operating button 621 operated. When the actuating element 62 moves, the return spring 622 is tensioned. The actuating element 62 finally comes with its bevelled end 620 to bear against the bevel 631 of the pawl 63 and pivots it against the action of the return spring 630. As a result, the pawl 63 releases the locking lug 614, and the actuating element 61 can now move return relaxing return spring 612 to its basic position, which is shown in dashed lines in Figure 2. This position is defined by the stop 613.

After the actuation button 621 has been released, the actuating element 62 also returns through the relaxing return spring 622 to the starting position shown, in which the stop 623 bears against the web 54. The pawl 63, which has now been released again, is now brought back into contact with the actuating element ö by the return spring 630.

If the changeover device 6 is to be brought back into the fiber removal position at a later time, this is done by actuating the actuation button 611 with the aid of the drive bolt 71 or by hand. The actuating element 61 arrives with simultaneous prestressing of the return spring 612 in the position shown, in which it is secured by the catch 63 which engages behind the catch 614.

In the switching device 6 shown in FIG. 2, the elongated hole 610 has a larger opening than the cross section of the vacuum line 50 or. 51, so that in an intermediate position the elongated hole 610 partially clears the connection of the suction channel 53 both to the first vacuum line 50 and to the second vacuum line 51 and thus simultaneously applies vacuum to both the fiber collecting surface 33 and the suction opening 52. This ensures that during switching the fibers 47 are not suddenly left alone, but are always in a suction air stream.

With some fiber materials and yarn counts, it is very important that the amount of fiber is precisely matched to the time of piecing. Since the times available for this also become shorter and shorter with increasing piecing speeds and the fibers 47 also arrive in the spinning rotor 30 with a delay which cannot be predetermined with sufficient accuracy, it is not possible to provide a precisely defined amount of fibers in the event of a sudden release of fibers . However, if the fibers 47 do not suddenly arrive in the spinning rotor 30, but rather with a gradually increased delivery rate, then an exact delivery of fibers into the spinning rotor 30 can also be achieved without the timing of the piecing and the release of the fibers 47 being coordinated with one another with narrow time tolerances have to . Since the fiber control for the piecing takes place during the transition from the first piecing phase to the second piecing phase, a gradual control of the switching device 6 is also advantageous only in this period, while the switching device 6 can otherwise be switched over at any speed .

In order to be able to actuate the switching device 6 at the desired switching speed, the control device 7 brings both drive bolts 71 and 72 into contact with the actuating buttons 611 and 621, which initially assume the position shown in FIG. 2. The actuating element 62 then pivots the pawl 63, which now releases the actuating element 61. The drive pin 71 now returns to its starting position. However, this return movement does not occur suddenly, but gradually with a predetermined, possibly changing speed, so that the actuating element 61 resting on the drive pin 71 with its actuating button 611 gradually returns to its dashed position. In due course, the pawl 63 is released again by releasing the control element 62. In the starting position, the actuating element 61 initially only releases the connection to the second vacuum line 51. In this fiber removal position of the switching device 6, the fibers 47 supplied by the delivery device are sucked out of the housing 10 through the suction opening 52 and thus prevented from reaching the spinning rotor 30.

After the actuating element 61 has traveled a certain distance, the elongated hole 610 has also reached a position such that the vacuum acting in the suction channel 53 already has an effect both in the first vacuum line 50 and in the second vacuum line 51. Some of the fibers 47 thus already get into the rotating spinning rotor 30, while another part of the fibers 47 is still sucked off via the suction opening 52 into the vacuum line 51. With increasing adjustment of the control element 61, the vacuum in the first vacuum line 50 is released more and more, while in the second vacuum line 51 the vacuum is throttled more and more. According to this changeover of the switching device 6, d. H . according to the adjustment speed of this control element 61, the supply of fibers 47 in the spinning rotor 30 is gradually increased, so that the amount of fiber required at the piecing moment can be precisely set in a simple manner and adapted to the increase in the thread take-off speed. This ensures a high level of security when piecing.

The switching device 6 described with reference to FIG. 2 permits both the actuation from a maintenance trolley 70 and the manual actuation, which is very simple due to the possibility of locking the adjusting element 61.

A simplified switching device 8, which is particularly suitable for actuating a maintenance car 70, will now be described with the aid of FIG. 3. An actuating element 81 is slidably mounted in a housing 80. The housing 80 is closed on both sides by a cover S2 or 83. Between the cover 8 and the actuating element 81 is a spring element 84, which thus acts on the actuating element 81 in the direction of the cover 83. The cover 83 has a central bore 830, through which an adjusting bolt 810 of the actuating element 81 extends.

The actuating element 81 has two control bores 811 and 812, of which the control bore 811 connects two pipe sockets 500 and 501 to one another when the spring element 84 is relaxed. These pipe sockets 500 and 501 serve to connect the first vacuum line 50 to the switching device 8. The second control bore 812 of the actuating element 81 connects two pipe sockets 510 and 511 to one another in its other end position, which are used to connect the second vacuum line 51 to the switching device 8 serve.

In the spinning position, the actuating element 81 is in the position shown, in which the control bore 811 is in alignment with the vacuum line 50 to the fiber collecting surface 33, so that the vacuum in the spinning rotor 30 is maintained while no vacuum is present at the suction opening 52. The fibers 47 thus reach the fiber collecting surface 33 in the spinning rotor 30 due to the negative spin pressure prevailing in the spinning rotor 30.

In order to bring the actuating element 81 into the fiber discharge position, in which the negative pressure at the fiber discharge opening 130 is prevented and therefore effective in the suction opening 52, it is sufficient to shift the actuating element 81 against the action of the spring element 84 by the force acting on the actuating bolt 810. As a result, the control bore 812 is aligned with the vacuum line 51, in which the vacuum is present at the suction opening 52 and the spinning vacuum is switched off in the spinning rotor 30. To reset the control slide 81, the release of the adjusting bolt 810 is sufficient, so that the spring element 84 can move the adjusting element 81 back into the spinning position shown. The pressure on the adjusting bolt 810 can also be done manually here. When automatic piecing is used, this adjusting bolt 810 is controlled from a movable maintenance carriage 7 via an electromagnet (not shown) or via a drive bolt 71. With a suitable arrangement of the pipe socket 500, 501, 510 and 511 and corresponding control of the control element 81 from the control device 7, the switching of the Umschaltvo direction 8 can also be gradual, d. H . gradually, perform.

So that no fibers 47 and yarn residues can get stuck in the housing 80 and in the adjusting element 81 during the suction, provision is made of two control bores 811 and 812 to ensure that the suction air always passes the switching device 8 in a straight line. This is achieved in that each vacuum line 50 and 51 j is assigned its own control bore 810 or 811, which can be brought into alignment with the pipe socket 500 and 501 or 510 and 511.

It can happen that at the moment of the U setting of the control element 81 just one or more fibers 47 in the transition from the pipe socket 510 into the control bore 812 or from the Steuerboh tion 812 in the pipe socket 511. It can also happen, albeit rarely, that fibers 47 are in the transition area between pipe socket 500 and control bore 811 or between control bore 811 and pipe socket 501 at this time. So that these fibers 47 or yarn ends cannot get caught between the adjusting element 81 and the housing 80 at these points, the edges 813, 814, 815 and 816 of the control bores 811 and 812 and the edges 800, 801, 802 and 803 assigned to them are the pipe sockets 500 , 501, 510 and 511 or the housing 80 are formed with sharp edges so that the stationary edges and the movable edges 800 and 813, 814 and 801, 802 and 815 as well as 816 and 803, which can be brought into alignment, form pairs of cutting devices. When the control element 81 is switched over, the fibers 47 and yarn remnants located in the area of these cutting devices are severed, so that a part thereof remains in the control bore 811 or 812 and the other part in the vacuum line 50 or 51. On Jamming of the actuator 81 is avoided in a safe manner

In a similar manner, the cooperating edges of the switching device 64 (FIG. 1) or 6 (FIG. 2) and the vacuum lines 50 and 51 or associated connecting pieces, not shown, can be designed as cutting devices.

Further modifications are possible by exchanging features with one another or by replacing them with equivalents and combinations thereof and fall within the scope of the present invention. For example, in the embodiments of the piecing device, which were explained with the aid of FIGS. 1 and 2, the two vacuum lines 50 and 51 are connected to a common vacuum source 5 and. connected to a common suction channel 53. If desired, a separate vacuum source can of course also be provided for each vacuum line 50 and 51, it being possible for these vacuum lines 50 and 51 to be connected to these vacuum sources by separate switching devices or by a common switching device 64, 6 or 8. This can be seen particularly clearly when looking at FIG. 3.

Even in the case of a changeover device 64 designed as a rotary body valve (FIG. 1), a simple drive from a maintenance carriage 70 is also possible by the changeover device 64 having a radially outwardly projecting adjusting bolt which in one direction is driven by the drive bolt 71 (FIG. 2) the maintenance car can be loaded. The provision can be made with the aid of a spring element which is configured as a torsion spring.

Using the example of an open-end spinning device having friction rollers 34, FIG. 1 shows that instead of the opening roller 11, a plurality of rollers which effect the fiber transport can also be provided, the first roller 14 serving to dissolve the fiber material to be spun and therefore designed as an opening roller is. The second roller 15, which is rotatably gelated between the opening device 1 and the friction rollers 34, is disk-like formed and has a collecting surface 150 on its circumference. The collecting surface 150 is connected to the opening device 1 via a feed channel 13 which opens approximately tangentially in the direction of the rotational movement of the collecting surface 150 and the width of which is adapted to the collecting surface 150.

The roller 15 is mounted on a hollow axis 152 fastened in the machine frame, which extends in a plane perpendicular to the axes 340 of the friction rollers 34, and is driven in the direction of the arrow 460. In the drawing, for the sake of clarity, the roller 15 has a relatively large distance from the gusset area of the friction rollers 34. However, the roller 15 should extend as far as possible into the gusset area so that the path of the fibers from the collecting surface 150 into the gusset area is as short as possible .

On the side of the gusset area of the friction rollers 34 facing away from the take-off rollers 41 and 42 there is a controllable suction air nozzle 35.

The fibers are held on the perforated collecting surface 150 by a suction air stream during their transport to the friction rollers 34. For this purpose, the disk-like roller 15 is connected to a suction device (not shown) via the hollow shaft 152. However, the suction air flow acts only in one sector 1 on the collecting surface 150, which in the direction of rotation of the roller 15 extends from the feed point of the fibers to the collecting surface 150 up to its separation point specified by a transfer sector II. The transfer sector II is kept separate from the suction air flow by partitions 151 so that the fibers 47 can detach from the collecting surface 150. Opposite the transfer sector II, the housing 10 has an opening 160 of a fiber feed channel 16 leading to the friction rollers 34.

It is advantageous to pneumatically support and accelerate the detachment of the fibers from the collecting surface so that is set that all fibers get into the spinning gusset. This is done by introducing an air flow into sector II, which flows through the collecting surface in the direction of the friction rollers 34. After at least one of the friction rollers 34 is vacuumed and the housing 10 extends sealingly to over the friction rollers 34, this flow arises by sucking in air from sector II. The air required for this is brought in through a pipe 153 inserted into the hollow shaft 152, which connects sector II with the atmosphere.

If this measure is not sufficient, the pipeline 153 can also be connected to a compressed air device and the collecting area 150 in the sector II can be subjected to a slight excess pressure. In addition to the described retention of the fibers on the fiber collection surface during their transport by pneumatic means or independently thereof, the fibers can also be held mechanically, for example by needles (not shown) arranged on the circumference of the collection surface 150, on the collection surface 150 - will be.

In order to avoid indifferent air flows in the area of the feeding of the fibers 47 on the collecting surface 150 and to expose the fibers 47 conveyed through the fiber feed channel 13 exclusively to an air stream stretching them and orienting them on the collecting surface 150 in their direction of movement, an air flow is to the sector II subsequent and up to the mouth of the fiber feed channel 13, sector III is kept free of flow by means of a fixed orifice 154. In addition, in the area of this sector I I I a circumferential wall 100 is provided which extends close to the collecting surface 150. In this peripheral wall 100, i.e. H . The suction opening 52 is arranged outside the fiber transport path between the fiber discharge opening 160 and the fiber feed channel 13.

For the spinning process, the fiber material is fed via the feed trough 21 as a sliver 40 by means of the delivery roller 20 of the dissolving roller 14 supplied, by means of which the sliver 40 is separated into fibers 47. The negative pressure in sector I of the roller 15 creates a transport air flow which transports the individual fibers 47 through the feed channel 13 to the collecting surface 150, on which the fibers 47 are deposited.

The fibers 47 fed with simultaneous duplication onto the circumferential collecting surface 150 are transported there via the sector I, on which they are held pneumatically and / or mechanically, to the mouth 160 of the feed channel 16 and, since the collecting surface 150 moves in the gusset area in the thread take-off direction , fed into the gusset area parallel to the thread axis in the transfer sector II. There they are angeu to the rotating open thread end and turned into a thread 4.

If a thread break occurs, the supply of fiber material to the opening roller 14 is interrupted by stopping the feed device 2. In addition, the negative pressure in the friction rollers 34 is switched off. In preparation for the piecing process, the end of the thread is returned to the spandrel of the friction rollers 34, which is supported by a suction air flow which is now effective in the suction air nozzle 35. Now the feed device 2 is switched on. So that no fibers 47 reach the friction rollers 34 in this case, a vacuum is applied to the suction opening 52 on the circumference of the roller 15 via the vacuum line 51. As a result, the air flow flowing through the pipe 153 in the transfer sector II is conducted into the suction opening 52. The fibers 47 supplied by the roller 14 onto the collecting surface 150 follow this air flow and are thus sucked into the vacuum line 51. At a point in time coordinated with the return of the thread, the negative pressure in the suction air nozzle 35 and in the negative pressure line 51 is switched off and instead the negative pressure in the friction rollers 34 or one of them is switched on. The thread 4 is withdrawn from the spinning gusset of the friction rollers 34 with the simultaneous incorporation of the fibers 47 now fed back into the spinning gusset. Even with a device according to FIG. 4 the fiber flow is controlled by the switching of the air flow described. The fibers 47 which are not required when the spinning process is interrupted are removed before they have reached the spinning unit. When piecing, the renewed delivery of the fibers 47 to the spinning unit ensures that only undamaged fibers 47 arrive there. The thread 4 produced thus has a high strength in the area of its piecing.

As Fig. 4 shows by broken lines, in an alternative embodiment of the device described, the suction opening 52 can also be arranged in the peripheral wall 101 of the opening roller 14 after the mouth 130 of the feed channel 13 provided there instead of in the peripheral wall 100 of the roller 15. In order to prevent fibers 47 from reaching the collecting surface 150 of the roller 15 when the suction opening 52 is located in the peripheral wall 101 of the opening roller 14 and is under this negative pressure, provision is made for the negative pressure in sector I the second roller 15 is controlled synchronously with the negative pressure in the friction rollers 34. Thus, if the fibers 47 are to be sucked off through the suction opening 52 in the peripheral wall of the roller 14, the negative pressure in the suction opening 52 is switched on and the negative pressure in sector I of the roller 15 and in the friction rollers 34 is switched off.

In order to facilitate the transfer of the fibers 47 from the opening roller 14 or the roller 15 to the subsequent mouth 130 or 160 of the feed channel 13 or 16, it can further be provided that the pipeline 153 alternately to the atmosphere b between. a compressed air source (not shown) or a suction air source (vacuum line 151) can be connected. For this purpose, the appropriately designed switching device (compare 64, 6 or 8) connects the pipe 153 to the atmosphere or the compressed air source when the fibers 47 are to leave the roller 15 through the fiber discharge opening 160 in the direction of the friction rollers 34, while the suction opening 52 is separated from the vacuum source 5 and a vacuum is applied to the friction rollers 34 via the vacuum line 50. However, if the fibers 47 are to leave the roller 15 not through the feed channel 16 but through the suction opening 52, the switching device separates the friction rollers 34 from the vacuum source 5 and the suction opening 52 following the fiber discharge opening 160 via the vacuum line 51 connected to the vacuum source 5. In order to ensure that the fibers 47 are also securely held on the collecting surface 150 in the area of sector II, the pipeline 153 is simultaneously connected to the vacuum line 51 mentioned. In this way, whenever the suction opening 52 is under vacuum, the sector II of this roller 15 is also under vacuum.

A further modification of the device for carrying out the described method is shown in FIG. 5. In this exemplary embodiment, the switchover device 9 has an aperture 90, with the aid of which the mouth 130 of the feed channel 13 can optionally be covered or released. For this purpose, the cover 90 is assigned an actuating device 91, which is only indicated schematically. With the aid of this actuating device 91, the diaphragm 90 can be adjusted manually by means of a drive bolt 71 driven by a drive device 92.

The actuating device 91 can be designed as desired, for example as a two-armed, possibly. cranked lever, as a slide with a run-on slope for the aperture 90, which is also designed as a slide. A spring element 93 can be assigned to the diaphragm 90 for resetting (FIG. 7).

The aperture 90 is arranged essentially in the extension of the peripheral wall 101 of the opening roller housing 10. It has at its end 907, which is first reached by the fibers 47 transported in the direction of the arrow 46 to the suction opening 52, a larger distance a from the opening roller 11 than that part of the peripheral wall 101 which, viewed in the direction of fiber transport, before this end 907 is arranged (distance a,). In contrast, the distance b between the opening roller 11 and the end 901 of the diaphragm 90 is that of the i the fibers 47 fed to the suction opening 52 is reached last, smaller than the distance b of the part following this end 908 from the peripheral wall 101 of the housing 10. In addition, according to FIG. 5 it is provided that the - seen in fiber transport direction (arrow 46) - rear End 908 of the screen 90 projects beyond the part of the peripheral wall 101 of the housing 10 which follows the fiber discharge opening 130. In this way, the cover 90 overlaps at its first end 907 the peripheral wall 101 of the opening roller housing 10 like a roof tile, while the second end 908 of the cover 90 in turn overlaps the peripheral wall 101 like a roof tile. All of these measures ensure that, when the mouth 130 is covered, there are no protruding edges on which fibers 47 can remain attached to or in front of the screen 90, which then release the mouth 130 of the feed channel 13 into the spinning rotor 30 or get onto the friction roller 34 and could impair piecing.

According to FIG. 5, the vacuum line 51 ends in a changeover device 512 designed as a non-return valve, with the aid of which the vacuum in the vacuum line 51 can be controlled. In the embodiment shown, the check valve is located in a chamber 513, which in turn is arranged at the end of the vacuum line 51, which faces the maintenance wagons 70 which can be moved along the spinning machine 36. An axial guide 514 for the valve cone 515 is located centrally in the chamber 513. The valve cone 515 is acted upon by a spring element 516, which is supported at its other end on spokes 517, with the aid of which the guide 514 is rigid with the peripheral wall of the chamber 513 connected is . The chamber 513 has on its side facing the maintenance carriage 70 an opening 519 surrounded by a valve seat 518, which opening 519 can be closed or opened by the valve cone 515.

In addition to the vacuum source 5 provided in the spinning machine 36, there is a second vacuum source 73 in the maintenance carriage 70. From the vacuum source 73, a telescopic suction air line 74 extends in the direction of the spinning machine 36. The suction air line 74 is assigned a drive device 75 through which the mouth 740 of the suction air line 74 is brought to the sealing system on the wall of the chamber 513 facing the maintenance car 70 can be withdrawn from this. In the mouth 740 de suction air line 74, a pin 742 is held with the aid of spokes 741, which axially projects beyond the mouth 740 in the direction of the spinning machine 36 and holds the valve cone 515 at a distance from its valve seat 518 when the mouth 740 is in contact with the chamber 513 thus the valve opens.

During normal spinning, the closure member 90 releases the mouth 130 of the feed channel 13, while the switching device 512 designed as a return valve takes its closed position. The fibers 47 thus pass through the mouth 130 of the feed channel 13 onto the fiber collecting surface 33 of the spinning rotor 30 or the friction rollers 34, where they are bound into the end of the thread 4.

If the thread 4 breaks, the spinning rotor 30 is stopped by a thread monitor (not shown) and the fiber feed to the opening roller 11 is prevented, the spinning vacuum in the spinning red 30 being maintained further.

After the affected spinning position has been reached, the maintenance carriage 70 actuates the diaphragm 90 with the aid of the drive bolt 71 via the actuation svorric device 91 and pushes it into the closed position, in which it covers the mouth 130 with respect to the interior of the housing 10 receiving the opening roller 11.

The spinning rotor 30 is now cleaned in a known manner by control from the maintenance carriage 70, and the thread end is prepared so that it has a favorable piecing shape. The spinning rotor 30 is then released again. This runs up. During the rotor ramp-up or after reaching the rotor operating speed the thread end is returned in the usual way with formation of a thread reserve into a stand-by position in the thread draw-off tube 32 (FIG. 1), where the negative pressure applied to the housing 31 is still effective.

The mouth 130 of the feed channel 13 is then covered. In addition, the connecting movement of the suction air line 74 emanating from the vacuum source 73 to the switching device 512 switches the latter, so that the vacuum generated in the vacuum source 73 is now present at the suction opening 52. Now the feed device 2 is switched on again. The fibers 47 fed to the opening roller 11 are thus conveyed over the covered opening 130 to the suction opening 52 and from there via the vacuum line 51, the chamber 513 and the suction air line 74 to the vacuum source 73 of the service vehicle 70.

Fibers 47, which were previously damaged by the milling drum 11 running while the feed device 2 was stopped, are thus removed and do not get into the spinning rotor 30.

In coordination with the thread return, the drive pin 71 releases the actuating device 91 again, which now returns the diaphragm 90 to its basic position, in which the mouth 130 of the feed channel 13 is released. The fibers 47 now go into the spinning rotor 30, where they connect to the end of the thread that has meanwhile reached the spinning rotor 30 by dissolving the thread reserve. The thread 4 is then drawn off in a known manner using the trigger rollers 41, 42 and the bobbin 44 (FIG. 1) from the sp inn rotor 30, the fibers 47 arriving on the fiber collection surface 33 being incorporated.

The aperture 90 does not have to be in a single and uniform pushing movement into the spinning rotor 30 or. on the friction roller 34 succeeded. As described using the example in FIG. 1, a substantial improvement in the piecing can be achieved by gradually switching the fiber stream. It has been shown that the Control of the fiber flow can be carried out even more simply and precisely if the negative pressure conditions in the negative pressure lines 50 and 51 are not controlled, but if instead the mouth 130 of the feed channel 13 is covered or released. In this case, it is not necessary to control the vacuum in the vacuum line 50 or in the vacuum line 51.

The gradual switchover of the fiber stream from the suction opening 5 to the fiber discharge opening 130 can therefore take place by gradually opening the mouth 130 through the edge 95 of the screen 90 (FIG. 6). As long as the mouth 130 of the feed channel 13 is covered, all fibers 7 pass through the suction opening 52 into the lower pressure line 51. If the mouth 130 is partially covered by moving the orifice 90, part of it transported by the opening roller 11 passes Fibers 47 into the mouth 130 and thus also into the spinning rotor 30. This partial covering of the mouth 130 of the feed channel 13 reduces the effect of the spinning vacuum at the mouth 130, so that the rest of the fibers 47 transported by the opening roller 11 follow as before, to the suction opening 52, where a higher negative pressure is present than at the mouth 130.

Since the fibers 47 are not very sluggish, it is not only those fibers 47 that enter the fiber discharge opening 130 that are guided by the air flow circulating with the opening roller 11 just above the open area of the mouth 130. Rather, fibers 47, which are located above the covered area of the mouth 130, are sucked in and entrained by the suction air stream leaving the mouth 130 of the feed channel 13. The proportion of the fibers 47 passing through the mouth 130 is thus higher than corresponds to the degree of opening of the fiber discharge opening 130, but the fiber stream can nevertheless be divided easily and safely in this way. Depending on the intermediate position selected, i.e. H . Depending on the negative pressure acting in the area of the mouth 130 of the feed channel 13, the proportion of the fibers 47 which pass through the mouth 130 into the spinning rotor 30 or to the friction roller 34 is more or less large . The fiber stream division can be controlled with more precision with the aid of an aperture 90, the closer this is to that with the resolution

3 roller 11 revolving fiber / air flow is located. In addition to

4 Prevention of fiber accumulation in front of the aperture 90 is this

5 is another reason why the diaphragm 90 should form the extension of the peripheral wall of the housing 10 as far as possible.

7

8 To ensure that no fibers can become trapped in the lateral guide slots, it can be provided for the feed channel 13

10 that this in the area of the aperture 90 on the spinning unit

1 facing a sudden increase in diameter in the

Has 12 type, as is known from divided fiber feed channels

13 ^is -

14

_] _ 5 When the full fiber flow to the spinning unit (spinning rotor 5 30 or friction rollers 34) finally starts to gel, it is in the suction opening

17 52 acting suction air flow meaningless. It no longer has an influence on fiber transport. In order to save energy costs for the generation of negative pressure, after the piecing process has ended, the negative pressure behind the coin 130 d. H . in the vacuum line 51, turned off. This

22 occurs in the embodiment shown in Figure 5 in that the

23 maintenance device 70, the suction air line 74 at least as far

24 withdraws that pin 742 releases valve cone 515. This 5 is thus supported by the spring element 516 against its valve

26 seat 518 brought. The opening 519 is closed so that air does not come

27 through opening 519 in one direction and in the other.

28 can flow. This prevents air from getting into the fiber

2g transport and could interfere with the spinning process in the opening roller

30 houses 10.

31

32 According to FIG. 6, the mouth 130 of the feed

33 nals 13 in that the slide-like diaphragm 90 with its massive

34 ven area 902 is brought over the mouth 130 and this

35 covers. 36 As previously discussed, the mouth 130 is closed when the fiber delivery is turned off, so that there is no risk of fibers 47 becoming trapped. The release of the mouth 130 poses no risk of fiber trapping.

In order to avoid the second thick spot that usually occurs in connection with the thread attachments without having to accept a thin spot immediately after the piecing, the control device 7 acts on the screen 90 via the drive device 92 in such a way that it moves unevenly while it is brought into its mouth 130 releasing position. This can be done by a continuous, but non-uniform or discontinuous movement.

Since the gradual changeover of the fiber stream is not solely about the degree of opening of the mouth 130, but primarily about utilizing the inertia of the fibers 47, a more precise division of the fiber stream can be achieved if the screen 90 is movable parallel to the axis 110 of the opening roller 11 is, as is the case according to FIGS. 5 and 5 (arrow 94).

The device described using the example of FIG. 6 requires a non-uniform movement of the diaphragm 90 for a gradual changeover. In order to achieve the desired fiber flow into the spinning rotor 30 or to the friction roller 34 even with a uniform movement of the screen 90, the screen 90 can have a control opening 900. Between its area 901, which completely covers the mouth 130, and the area 902, which causes the mouth 130 to be completely uncovered, it is profiled in the feed channel 13 (FIG. 1) in accordance with the desired fiber flow profile, which is determined by the degree of opening of the mouth 130 7 ⁾ .

According to FIG. 7, the control opening 900 has an area 903 which adjoins the area 901 and which completely clears the mouth 130. This area 903 is adjoined by an area 904 which only a reduced cross section of the mouth 130 is released by a profiling designed as a nose 905. This is then followed by the region 902, which causes the mouth 130 to be completely released during the spinning process.

In preparation for the piecing process, with the mouth 130 covered, the fiber stream is guided over the mouth 130 of the feed channel 13. With the aid of a diaphragm 90 according to FIG. 7, the orifice 130 is then opened more and more through the area 903 during the lifting movement of the diaphragm 90 caused by the drive bolt 71 until it is completely released. Thus, many fibers 47 quickly enter the spinning rotor 30. The thread 4 is spun on and pulled off at the same time as the fibers are being fed into the spinning rotor 30, so that after the spinning no longer many fibers 47 can lay on the fiber ring Reducing the free cross section of the mouth 130 temporarily restricts the fiber feed into the spinning rotor 30 with the aid of the ase 905. With a rapid increase in the thread take-off speed, the full amount of fibers can then reach the spinning rotor 30 by opening the mouth 130, as shown in FIG.

Depending on the course of the thread take-off speed, a flatter or steeper curve course can also be provided for the edge 906 of the nose 905. Regardless of whether it is designed as a nose 905 or not, the profiling can have an opening cross-section ^that is increasingly releasing a straight or curved course.

Particularly inconspicuous attachments are obtained if, by appropriately shaping the control opening 900 or correspondingly controlling the movement of the diaphragm 90, there is a brief interruption in the fiber stream supplied through the feed channel 13 to the fiber collecting surface 33, which is thus temporarily discharged via the suction opening 52 for this duration is - and the fiber stream of the Fasersa mmeifläche 33 is supplied again only after the end of the thread has reached this fiber collecting surface 33 and the withdrawal of the thread 4 has begun. 1 A further design of the spinning device is now based on the

2 Fig. 8 to 12. In this version, the opening roller

3 Zen housing 10 in the area of the feed device 2 against supply air flow

4 gen closed. As these figures show, the housing part 17 has

5 only a sliver feed opening 170 which, however, is uncontrolled

6 Supply air flows into or out of the opening roller housing are not

7 permits. Furthermore, a switchover device is located in the vacuum line 51.

8 device 85 provided, which the vacuum line 51 alternately

9 blocks or releases. The switching device 85 is designed as a slide valve 0, which is acted upon by a spring element 850 in the closed position 1 and by the connecting movement of the suction air nozzle 74 (FIG. 5) arranged on the 2 service car 70 (FIG. 5)

13 vacuum line 51 can be brought into the release position. Farther

14, the dirt separating opening 12 is assigned a closure member 120.

15 net, which is designed as a flap in the embodiment shown.

16

17 Such a device as described above enables

18 a reversal of the fiber stream in a simple manner without i g requiring a control of the vacuum in the housing 31

20 is. The vacuum line 51 is connected to a vacuum source (e.g. 73

21 connected to maintenance car 70), whose vacuum is higher than

22 is the spinning vacuum. The switching device 85 is at

23 Place the suction air line 74 on the vacuum line 51.

24 gene the effect of the spring element 850 in its flow position

25 brought.

26

27 If the flap-like closure member 120 is now closed, so

28 the required air can be fed through the only

2g housing 10 remaining opening, namely the mouth 130 of the Speisek

30 nals 13, take a breath. To prepare for piecing is therefore on

31 scope of the opening roller by closing the closure member 120

32 generates such a vacuum flow that despite unchanged

33 spinning vacuum the air flow is reversed. The so generated

34 takes air flow from the feed channel 13 into the suction opening 52

35 the fibers 47 transported by the opening roller 11

36 (Fig. 8). 1 Then, by partially opening the flap-like lock

2 closing device 120 the effect of the suction opening 52

3 seeing vacuum reduced so much that a division of the

4 fiber flow takes place. Some of the fibers 47 thus follow

5 as before into the suction opening 52, while another fiber

6 part through the mouth 130 of the feed channel 13 onto the fiber collecting

7 area 33 arrives. Depending on the opening degree of the closure organ

8 nes 120 there is a more or less large reversal of the air stream in the feed channel 13, so that the degree of opening of the

10 closure member 120, the proportion of the fiber stream supplied to the fiber collecting surface 33 can be determined (FIG. 9).

12th

13 Are enough fibers 47 of the fiber collecting surface 33 in this way

14 have been fed (see fiber ring 470 in the spinning rotor 30), so

15 again other than the air flow now generated in the feed channel

16 supply air flows in the opening roller housing 10 switched off. By

17 the supply air flow in the feed channel 13, the fibers 47 again

Sucked through the suction opening 52 18 (FIGS. ^'10).

19

Then the thread 4 is fed to the spinning rotor 30. In time

21 Vote on this, the closure member 120 is non-uniform

22 moved to the dirt separation opening 12 according to the

23 wanted to release fiber flow in the feed channel 13 (Fig. 11).

24 This control is carried out by a suitable control device,

25 which is arranged, for example, on the maintenance car and above

26 a drive device 92 on the flap-like closure member 120

27 acts (Fig. 5). The control takes place in such a way that thick

28 and thin spots both in the piecing itself and in that

29 subsequent thread piece can be avoided. 30

31 Finally, the closure member 120 reaches its full opening

32 position, even if the thread take-off is at full speed

33 has reached. By withdrawing the suction air line 74 from the

34 vacuum line 51, the switching device 85 is released,

35 which, by the action of the spring element 850, the connection 36 shut off between the vacuum channel 51 and the suction opening 52. Thus, no supply air can enter the opening roller housing 10 during the normal spinning process (FIG. 12).

The control of the supply air flow for controlling the fiber flow can take place at various points on the opening roller housing 10, for example also on the housing part 17 receiving the feed device 2. However, if a dirt separating opening 12 is provided, as in the exemplary embodiment shown, this also immediately forms the supply air opening Control of the fiber flow. After the vacuum channel 51 has been spun on and shut off, the dirt separation opening can then be opened or closed as desired, depending on whether or not dirt should be separated.

In the exemplary embodiment described, the closure member 120 is located at an uncritical point in the fiber transport. At this point, no fibers 47 emerge from the opening roller housing 10 since they do not have a sufficiently high centrifugal force due to the speed, which is still too low.

As described above, the housing part 17 and the closure member 120 prevent other supply air flows from entering the opening roller housing 10 apart from the feed channel 13. As a result, the fiber stream is very sensitive to changes in the vacuum in the vacuum channel 51. This offers the possibility, even if no dirt separating opening 12 is provided in the opening roller housing 10, to bring about a precise control of the fiber flow by means of a relatively small change in the vacuum in the vacuum channel 51.

The control of the vacuum in the vacuum channel 51 or the flap-like closure member 120 can also be carried out here in the example shown in FIG. 2, 3 and 5 described manner from a maintenance car 70 from. Another embodiment of a switching device 86 is shown in FIG. 13. Instead of the slide valve-like switching device 85 (FIGS. 8 to 12), a flap 860 is provided here, which is articulated above the mouth 861 of the vacuum line 51 facing the maintenance car 70. The mouth 861 forms a valve seat which is inclined obliquely in such a way that the flap 860 seals against the valve seat due to its own weight. The flap 860 is located together with its mouth 861 of the vacuum line 51 in a chamber 862 which is open on its side facing the maintenance car 70. From the maintenance trolley 70, the mouth 740 of the suction air line 74 can be sealingly brought into contact with the open side of the chamber 862, as shown in FIG. 13 is indicated by dashed lines.

As long as the suction air line 74 is not in contact with the chamber 862 or as long as there is no negative pressure on the suction air line 74 in the open side of the chamber 862, the flap 860 assumes the position shown in full line with the valve 860 sealingly against the flap Mouth 861 is supported by the negative pressure prevailing in the opening roller housing 10. If vacuum is applied to the suction air line 74 after the mouth 740 of the suction air line 74 is applied to the chamber 862, the flap 860 lifts up from the mouth 861 (dashed position 860 '), and the fiber stream can get into the suction air line 74.

Although the devices according to FIGS. 5 to 13 have only been described using the example of opening rollers 11, it goes without saying that they can also be used in conjunction with an additional roller 15 according to FIG.

A changeover device 512 or 86 designed as a check valve for controlling the negative pressure in the negative pressure line 51 has been described above. However, it is also conceivable to provide a shut-off valve on the spinning machine 36, which is actuated from the maintenance carriage 70 and the vacuum line 51 with a connected or not connected to the spinning machine 36 itself, which is independent of the vacuum source 5. It is also conceivable to operate a switch from the maintenance carriage 70, via which a fan is switched on or off. Likewise, the suction air line 74 (FIG. 5) can also be connected via the maintenance carriage 70 to a vacuum source provided on the spinning machine 36. In principle, the fiber flow can be controlled by changing the vacuum ratio, whereby either the spinning vacuum or the suction vacuum or both vacuum pressures can be changed.

Claims

Patent claims

1. A method for piecing an open-end spinning device with a feed device for supplying fiber sliver and an opening roller arranged in a housing, from which the individual fibers are fed via a feed channel by means of a suction air flow to a fiber collecting surface for thread formation and in which a thread end during piecing is returned to the fiber collection surface, from which the previously returned thread is then drawn off again with continuous incorporation of fibers, the feed device being switched on in preparation for piecing and the fiber stream being deflected on its way to the fiber collection surface and fed to a suction device while the feed device is running, since - characterized in that in order to prepare the piecing process outside of the fiber transport path, a vacuum is brought into effect on the circumference of the opening roller, which is greater than that at the mouth of the food channel effective spinning vacuum, so that the fiber stream is led over the feed channel mouth and sucked off, and that this vacuum is deactivated at the beginning of the actual piecing process, so that the fiber stream is fed to the fiber collecting surface.

2. The method according to claim 1, characterized in that in preparation for the piecing process, the spinning vacuum at the mouth of the feed channel is reduced in its effect so that the fibers are passed over it, and that at the start of the actual piecing process, the vacuum outside the fiber transport - way out of effect on the circumference of the opening roller and - - -% 5 -

instead, the spinning vacuum at the mouth of the feed channel is brought back to its full effect.

3. The method of claim 2, d a d u r c h g e k e n n - z e i c h n e t that to reduce the effect of the spinning vacuum at the mouth of the feed channel, the spinning vacuum is switched off.

4. The method of claim 2, d a d u r c h g e k e n n - z e i c h n e t that in order to reduce the effect of the spinning vacuum at the mouth of the feed channel, this is at least partially covered.

5. The method according to one or more of claims 1 to 4, characterized in that at the start of the actual piecing process the effect of the negative pressure outside the fiber transport path on the circumference of the opening roller over a period of time in its effect reduced or the effect of the spinning negative pressure at the mouth of the feed channel is increased again, so that the fiber stream gradually reaches its full strength in the feed channel.

6. The method of claim 5, d a d u r c h g e k e n n - z e i c h n e t that the increase in fiber flow takes place in dependence on the increase in the thread take-off speed.

7. The method according to claims 5 or 6, characterized in that when spinning only a small proportion of the fiber is initially fed to the fiber collecting surface, while at the same time the remaining fibers are passed over the mouth of the feed channel, that the thread end is then returned to the fiber collecting surface and that after incorporation of the fibers located on the fiber collecting surface, the proportion of fibers fed to the fiber collecting surface is increased.

8. The method according to one or more of claims 1 to 7, characterized in that in preparation for the piecing process, the fiber stream is first led away over the mouth of the feed channel, that the fiber stream is then briefly fed to the fiber collection surface, then again passed over the mouth of the feed channel and that the fiber stream is only fed back to the fiber collecting surface after the thread end has reached the fiber collecting surface and the thread has started to be drawn off.

9. The method according to one or more of claims 1 to 3 and 5 to 8, characterized in that for the preparation of piecing on the circumference of the opening roller, a vacuum flow is generated such that, with the spinning vacuum unchanged, an at least partial reversal of the air flow in the feed channel takes place and the air flow thus generated on its way out of the feed channel into the suction provided on the circumference of the opening roller at least partially entrains the fibers transported by the opening roller.

10. The method of claim 9, d a d u r c h g e k e n n - z e i c h n e t that other supply air flows are turned off in the opening roller housing to reverse the air flow in the feed channel.

11. The method according to claim 10, that the switching of the other supply air flows takes place in a controlled manner to control the amount of fiber supplied to the fiber collecting surface.

12. The method according to one or more of claims 1 to 11, characterized in that the negative pressure outside the fiber transport path on the circumference of the opening roller is switched off after the piecing process has ended.

13. The method according to one or more of claims 1 to 12, that the feed device is stopped when a thread break occurs and the feed device is switched on again after cleaning the fiber collecting surface, but the fiber stream is led over the feed channel mouth and suctioned off.

14. The method according to one or more of claims 1 to 13, characterized in that in preparation for the piecing process for rotor spinning the spinning vacuum in the rotor housing is first effective, the thread end is fed into the spinning device without touching the fiber collecting surface, and that the spinning vacuum is then switched off and the vacuum outside the fiber transport path is brought into effect at the periphery of the opening roller, so that when the feed device is switched on again, the fiber stream is led over and sucked off over the feed channel mouth, and that at the beginning of the actual piecing process this vacuum is switched off and the Spinning vacuum is switched on, so that the fiber stream is fed to the fiber collecting surface and the thread end is returned to the fiber collecting surface.

15- Method according to one or more of claims 1 to 14, so that in order to prepare the piecing process, instead of the circumference of the opening roller, a negative pressure outside the fiber transport path is brought into effect on the circumference of a fiber transport roller connected downstream of the opening roller.

16. Device for carrying out the method according to one or more of claims 1 to 15, with a vacuum source, which generates a suction air flow for fiber transport through the feed channel to the fiber collecting surface, and a suction opening in the peripheral wall of the opening roller housing outside the fiber transport path, thereby - is characterized in that the vacuum source (5) can be connected to the suction opening (52) via a switching device (6, 64, 8, 85, 9) and a vacuum line (51).

17. The apparatus of claim 16, d a d u r c h g e k e n n - z e i c h n e t that the vacuum source (5) via the switching device (6, 64, 8) is alternately assigned to the fiber collecting surface (33) as spinning vacuum or the suction opening (52) for suctioning the fibers.

18. Device according to claims 16 or 17, so that in an intermediate position of the switching device (6, 64, 8) both the fiber collecting surface (33) and the suction opening (52) are simultaneously subjected to negative pressure.

19. The device according to one or more of claims 16 to 18, characterized in that the switching device (8) has two control bores (811, 812), one of which is in alignment with a first vacuum line (50) to the fiber collecting surface (33) and the other can be brought into alignment with the second vacuum line (51) to the suction opening (52).

20. The device according to one or more of claims 16 to 19 _» characterized in that the stationary edges (800, 801, 802, 803) and the movable edges (813, 814, 815, 816) of the switching device (6, 64, 8) are designed as cutting devices.

21. The device according to one or more of claims 16 to 20, characterized in that the opening roller housing (10) in the region of the feed device (2) is closed against supply air flows.

22. The apparatus according to claim 21, so that the opening roller housing (10) has a controllable supply air opening (12).

23. The device according to claim 22, so that the controllable supply air opening (12) is arranged in the peripheral wall (101) of the opening roller housing (10) between the feed device (2) and the mouth (130) of the feed channel (13).

24. The device according to claim 23, so that the dirt separating opening (12) is designed as a controllable supply air opening.

25. The device according to one or more of claims 22 to 24, that the supply air opening (12) can be controlled from a maintenance carriage (70) which can be moved along several spinning devices.

26. The device according to one or more of claims 22 to 25, so that the supply air opening (12) is assigned a closure member (120) designed as a flap.

27. The device according to one or more of claims 22 to 26, d a d u r c h g e k e n n z e i c h n e t that the supply air opening (12) is assigned a closure member (120) which is non-uniformly movable by a control device (7).

28. The device according to one or more of claims 16 to 27, characterized in that in the opening roller housing (10) is provided a controllable aperture (90) covering the mouth (130) of the feed channel (13).

29. The device according to claim 28, so that the diaphragm (90) is arranged essentially in the extension of the peripheral wall (101) of the opening roller housing (10).

30. The device according to claim 29, characterized - characterized in that the diaphragm (90) at its - seen in the fiber transport direction - first end (907) of the peripheral wall (101) of the opening roller housing (10) is overlapped like a roof tile, while the second end (908) overlaps the peripheral wall (101) of the opening roller housing (10) like a roof tile, so that - seen in the fiber transport direction - no protruding edges arise.

31. The device according to one or more of claims 28 to 30, d a d u r c h g e k e n n z e i c h n e t that the diaphragm (90) parallel to the axis (110) of the opening roller (11, 14) is movable.

32. Device according to claim 31 _» characterized in that the diaphragm (90) has a profile (905) controlling the degree of opening.

33. Device according to claim 31, that the profile is designed as a nose (905).

34. Device according to one or more of claims 28 to 33, d a d u r c h g e k e n n z e i c h n e t that acts on the diaphragm (90), a control device (7) which moves the diaphragm (90) non-uniformly.

35. Device according to one or more of claims 28 to 34, characterized in that the switching device (6, 64, 8, 85, 86, 512, 9) from one of several spinning devices along movable maintenance carriage (70) is controllable.

36. Device according to claim 35, so that the switching device (512, 86) is designed as a check valve.

37. Device according to one of claims 16 to 36, - characterized in that the switching device (6, 8, 85, 512, 9) is actuated in one direction of movement by a control drive (92), while for the resetting a spring element ( 612, 622; 84; 850; 516; 93) is provided.

38. Device according to one or more of claims 16 to 37, characterized in that a second vacuum source (73) is provided on a maintenance carriage (70) which can be moved along several spinning devices, to which the suction opening (52) instead of the first vacuum pressure source (5th ) can be connected.

39. Device according to claims 35 and 38, so that the switching device (512) can be controlled by the connecting movement of a suction air line (74) emanating from the maintenance car (70) to the switching device (512).

40. Device according to claims 35 and 38, so that the switching device (86) can be controlled by the vacuum in a suction air line (74) emanating from the maintenance car (70).

41. Device according to one or more of claims 16 to 40, characterized in that the opening roller (14) is followed by a fiber transport roller (15) and the suction opening (52) instead of the peripheral wall (101) surrounding the opening roller (14) in a Transport roller (15) surrounding the peripheral wall (100) is arranged.