JPH0433894B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention involves suctioning a yarn end through a suction pipe, cutting it to a predetermined length for starting spinning, and cutting it to a predetermined length for splicing in an open-end spinning device. The present invention relates to a yarn splicing method for preparing yarn ends that have been cut at the same time, and an apparatus for carrying out this method.

Prior Art In order to resume spinning in an open-end spinning device, the yarn end required for splicing is pulled out from the winding frame, cut to a predetermined length, and then the yarn end thus prepared is transferred to the open-end spinning device. It is known to return the fibers to the collecting surface and here to combine them with the fibers fed to the collecting surface (German Patent Application No. 1710021). Cutting to a predetermined length is
This is usually done by the spinner by tearing the yarn through the fingernails or, if the yarn is thick, through the edges, so that a frayed but defined yarn end is formed. Since sufficient conditions for starting spinning cannot usually be obtained with yarn ends obtained by simply cutting, the success rate of yarn joining is insufficient, especially when the rotor rotational speed is high.

It is also known to shorten threads purely pneumatically to the desired length for joining (DE 2203198 A1). At that time, the free end of the thread is
It is untwisted by the swirling air current and pulled away from the rest of the yarn by pneumatic tension, so that a yarn end with a whisker of fibers is formed.

Even excluding the fact that in this way it is not possible to obtain a precise cutting position and therefore a predetermined length of the thread end,
It has been found that if the rotor rotational speed is high during yarn joining, the success rate of the joining process is still insufficient.

Object of the invention The object of the invention is to improve automatic yarn joining in open-end spinning machines, especially with regard to the success rate of yarn joining at high rotor rotational speeds or high spinning speeds.

Structure of the Invention According to the present invention, this problem is solved as follows. That is, at least one tube separate from the suction tube
A tubular shield having two nozzles forms a turbulent twisting airflow, and the free end of the thread, which is held fixed after being cut to a predetermined length, is exposed to the turbulent airflow, causing the end of the thread to vibrate like a whip. At the yarn end, the individual fiber ends are exposed and spread out from the yarn surface, and the yarn ends prepared in this way are subsequently conveyed to the fiber collection surface of an open-end spinning device.

To my surprise, I discovered the following: In other words, this method significantly improves the success rate of yarn joining even when the rotor rotational speed or spinning speed is high, so it is not necessary to reduce the rotor rotational speed for the joining process compared to the normal spinning process. Totally unnecessary. This method has the advantage that the length of the yarn to be prepared can be freely selected regardless of the staple length and can be adapted to various spinning start conditions.

The surprising effectiveness of this method is clearly based on the following. In other words, the yarn ends are coarsened at a predetermined length that can be optimized depending on the spinning parameters, and the fibers are not untwisted or parallelized at this time, so there is no loss of strength in this area. . A more rough surface is formed in this part of the yarn end, and the fibers on this surface, which are separated but still bonded on one side, have a very good affinity for the fibers in the spinning rotor or other fiber collection surfaces. , the bonding is rapid and extremely strong.

Preparation of the thread ends is simplified as follows.
That is, the thread to be prepared for splicing is extended from the thread receiving position to a point beyond the preparation device and then cut to a predetermined length, and the free end of the thread thus formed is then sucked into the preparation device. .
The free end of the thread is thus caught in the air stream immediately after cutting the predetermined length and automatically inserted into the preparation device.

Cutting to exact length can be done with a cutting device. Roughening of the surface of the free end of the thread is promoted by striking the free end of the thread against an edge-like protrusion or rough surface. Successful spinning initiation and bonding of the fibers at the yarn free end are further improved if the yarn free end is prepared longer than the staple length.
During preparation, thread the thread from the free end to the staple length.
It is advantageous to hold them fixed at a distance of 1.5 times.

Optimal spinning start conditions during open-end rotor spinning are obtained by providing a yarn free end with a length approximately equal to the diameter of the spinning rotor.

In order to simplify the handling of the thread for preparation, after cutting the predetermined length, the free end of the thread is moved to the required distance for preparation with respect to the fixed holding point. Insertion of the starting yarn into the spinning device is simplified as follows. That is, after cutting to a predetermined length, the free end of the yarn is brought to a suitable length for insertion into the spinning device and, after insertion, returned to the joining position, where it is released for the joining process.

The apparatus for carrying out this method generally has the following characteristics. That is, apart from the suction pipe, a tubular shield is provided near the thread holding device, and this tubular shield is associated with at least one compressed air nozzle or suction air nozzle, and this nozzle is used to hold the thread end fixedly held by the whip. It vibrates to form a turbulent twisting airflow.

Rapid preparation of yarn ends can be done as follows. At least one in the area of the vibrating thread end
There are two edge-like protrusions or a roughened surface. Therefore, the compressed air nozzle
It faces towards the inner wall of the shield. Particularly effective air turbulence is obtained in that the compressed air nozzles are oriented into the shield at an acute angle to the central axis of the shield. In order to further promote roughening of the free end surface of the yarn, a plurality of compressed air nozzles open in the shield, the openings of these nozzles are opposite to each other, and the nozzles are operated in an alternating order. It's summery. If the individual fibers leave the separation position or yarn surface during coarsening of the yarn free end, the shield can be connected to the suction conduit.

When using the intake air nozzle, this nozzle
Seen in the direction of flow, one or more auxiliary air openings are provided after the inlet opening for the free yarn end. As a result, the thread ends bear particularly strongly against the rough inner surface of the shield. The auxiliary air opening is arranged eccentrically relative to the bore axis of the intake air nozzle so as to open into this nozzle. Preferably, the auxiliary air opening opens tangentially to the inner diameter of the intake air nozzle, so that an effective turbulent torsional airflow is created which prevents the yarn from untwisting.
The suction air nozzle is simple to manufacture if the auxiliary air opening is formed by a groove-shaped recess in the nozzle wall.

To ensure a sufficiently large turbulent air flow, the flow cross-sectional area of the inlet opening is smaller than that of the auxiliary air opening. If a normal spinning negative pressure of 700 mm water column is applied for yarn preparation, the diameter of the inlet opening for the yarn free end is between 2 and 5 mm, depending on the yarn thickness.

Advantageously, the inlet opening is arranged in the eyelid from above in the wall of the intake air nozzle. The device is thereby easily accessible and therefore easy to maintain. Insertion of the free thread end into the preparation device is facilitated if the inlet opening has a funnel-like enlargement, on which the thread holding device can be positioned closely. In an advantageous configuration for creating a strong and optimally synchronized turbulent air flow by spinning the yarn, four auxiliary air openings, staggered relative to each other, are distributed over the circumference of the intake air nozzle and each auxiliary air openings are connected to outside air via a bypass. The intake air nozzle is connected to the intake conduit via the shield. In this case, it is particularly advantageous if the suction line is connected to a suction device which creates a spinning vacuum. This is because the spinning negative pressure is already applied to the fibers and yarns from the point of view of the spinning process. Therefore, no excessive load is applied to the yarn ends. In an arrangement that simplifies the manufacture of the device, the intake air nozzle is formed integrally with the shield.

A thread introduction aid at the thread end is provided by the shield having a longitudinal slit. Optionally, the shield can be provided with slits in the direction of movement of the threads towards the fiber collection surface. In an advantageous embodiment, the shield is a square tube and is arranged substantially in the direction of exit of the thread from the thread holding device. The turbulent flow thereby promotes a whipping movement of the yarn ends. However, the shield may also be arranged transversely to the direction of exit of the thread from the thread holding device. For structural simplicity, the shield is fixedly arranged within the swing range of the thread holding device. Alternatively, the shield may be brought closer to the free end of the thread. The shield can then be used at the same time to pass the free end of the yarn into the yarn withdrawal tube of the spinning device. A shield inner diameter in the range of 8 to 15 mm at a given negative pressure of 700 mm water column has been found to be optimal according to prior knowledge for preparing the free end of the thread with an inspiratory flow. It is advantageous to form the shield as a sleeve and to arrange this sleeve in an axially movable manner in the support of the nozzle.

Description of examples Embodiments of the present invention will be described below with reference to the drawings.

Next, the invention will be explained in connection with an open-end rotor spinning machine equipped with a maintenance wheel for yarn joining. However, the invention can also be advantageously applied to other open-end spinning devices, for example friction spinning devices.

A spinning machine 1 (FIG. 1) usually has a plurality of spinning devices. Inside the casing 10 is an open-end spinning device for forming the yarn. The casing 10 has a yarn withdrawal tube 11 through which the spun yarn (dashed line) exits from the open-end spinning device.
It is drawn out by a pair of drawing rollers 12. The thread is wound around the thread spool S by the thread winding device 13.

A maintenance device W is provided for operating the spinning position, which maintenance device W is movable along the spinning position and is capable of carrying out various maintenance processes, for example restarting the spinning of the yarn at the spinning position after a yarn breakage. identify To do this, search the spool for the broken thread on the spool, pull out the end of the found thread from the spool, and
It is then necessary to insert it into the spinning device again, so that it comes into contact with the fibers present in the spinning device and thus restarts the spinning process. If the fibers in the spinning device and the yarn ends are not successfully re-bonded in the first bonding process, the maintenance device repeats the bonding attempt, which results in a loss of time;
Therefore, the maintenance capability of the maintenance equipment is significantly affected. In addition, the overall efficiency of the machine is reduced due to the increased breakdown time of the spinning device. It is therefore important that the success rate during bonding is as high as possible.

If an interruption in the spinning process occurs, a maintenance device is normally called to the relevant spinning position in order to carry out the necessary steps for resuming the spinning process. Before resuming the actual spinning as usual, the spinning device is first cleaned of residual fibers and dirt.

In the device illustrated here, in order to restart spinning, a suction pipe 14 is arranged on the vehicle of the maintenance device W, and this suction pipe is movable from an inoperative position to a yarn receiving position shown by a broken line. In position the opening of the suction tube 14 is in front of the spool S, which is lifted from the drive roller and driven in the unwinding direction, and receives the thread end. The thread is suctioned through the suction tube 14 and this suction tube is returned to the inoperative position again, with the yarn exiting through the longitudinal slit of the suction tube 14 and being exposed to the winding. It extends from S to the lower part of the suction pipe 14.

In order to return the unraveled yarn end received from the spool S by the suction pipe 14, a pair of clamp rollers 2,
A roller pair 20 is provided, which roller pair serves as a thread holding device and can be rotated by drive means, not shown. The roller pair 2, 20 is mounted on a swing arm 30 on the vehicle of the maintenance device W.
It is cantilevered on the shaft 3 and is swingable about an axis 3 between a yarn receiving position and a yarn discharging position for returning the yarn end into the yarn outlet tube of the open-end spinning device. The pair of rollers 2, 20 grips the yarn extending from the spool S to the lower part of the suction pipe 14 by swinging, and then the yarn F is cut at a predetermined position below the pair of rollers 2, 20 held by the clamp. The cutting is effected by a blade 15, which cooperates with an anvil roller 16 to form a predetermined thread end (FIG. 3 position). The cut thread piece is sucked out by the suction tube 14.

The distance from the fixed holding point of the thread F given by the clamp lines of the roller pairs 2, 20 to the cutting position is therefore the distance between the free end of the thread to be prepared for the start of spinning.
The length of F' can be arbitrarily selected and determined depending on the spinning start conditions, regardless of the staple length. At that time, if the length of the yarn free end F' is longer than the staple length, and preferably 1.5 times the staple length,
It has been found that problem-free starting of spinning under various starting conditions is possible with a high success rate and that a particularly strong bond is produced.

In order to prepare a yarn end F' of a predetermined length, the rollers 2, 20 are equipped with a compressed air nozzle 5 connected to the compressed air conduit 4, which nozzle It opens into a tubular shield 51 located within the range of motion (FIG. 2). The shield 51 is disposed by the holding portion 50 approximately in the direction in which the thread F exits from the roller pair 2, 20. The compressed air nozzle 5 is connected to the inner wall 5 of the shield 51.
2, preferably shield 51
It forms an acute angle α with the central axis of . According to prior knowledge, an angle α of approximately 45° has been found to be particularly desirable. The shield 51 is particularly advantageously formed as a square tube, but other cross-sectional shapes are also possible. To facilitate the preparation of the thread free end, the inner wall 52 has at least one protrusion extending in the longitudinal direction of the shield 51 and having a sharp edge;
or have a rough surface. A rough surface can be provided at a desirable cost by applying sandpaper to the inner wall 52, in which case commercially available grain sizes are usually sufficient.
The turbulent air flow required for the preparation of the yarn ends can be enhanced by a second compressed air nozzle 5', shown in broken lines in FIG. Therefore, the second compressed air nozzle 5'
It is advantageous to communicate into the shield 51 at the same angle α as the compressed air nozzles 5, the openings of the two compressed air nozzles 5 and 5' facing each other.
Compressed air is alternately applied to the nozzles by suitably controlled valves.

After reaching a predetermined length, the roller pair 2, 20 is swung upwards on the shield 51 together with the fixedly held yarn free end F' (positions in FIGS. 3 and 4). By opening the valve at the same time or immediately after, the compressed air
is blown into the shield 51 through the nozzle 5 and forms a turbulent air flow, 2 as shown in FIG. 3 (position).
In a configuration with two nozzles, the nozzles 5 and 5' are formed in alternating order. At this time, due to the injector action generated at the entrance of the shield 51, the free end of the yarn is
F' is sent into the shield 51. Unlike this processing method, the yarn free end F' is returned to the direction of the yarn winding S by the pair of rollers 2, 20 after being made into a predetermined length, and the returned yarn length portion is transferred to, for example, a pneumatic yarn. It is also conceivable to accommodate it by means of a reservoir. By reversing the direction of rotation of the roller pair 2, 20, the free end F' of the yarn after swinging upward to the shield 51 is again brought to the initial predetermined length with respect to the fixed holding point and is moved by the air flow. It is sucked into the shield 51. In this treatment method, only short pieces of thread protrude from the roller pair during the rocking of the roller pair 2,20. This treatment method can be advantageously used to improve handling even after preparation due to the introduction of the yarn end into the yarn draw-off tube.

The turbulent airflow guided by the shield 51 is
The free yarn end F' is vibrated like a whip, so that the individual fiber ends are exposed and spread out from the yarn surface. This is shown schematically in FIGS. 3 and 4 (position). The exposing of the fiber ends is furthermore effected by means of a rough wall 52 or at least one edge-like protrusion in the shield 51 which is located in the region of the oscillating yarn end F' and which the yarn end F' hits due to the turbulent air flow. This is facilitated and the time required to prepare the yarn free end F' is minimized. The individual fibers or fiber pieces loosened from the separation position or from the thread pieces during this preparation are removed by means of a suction conduit 53 following the shield (FIG. 2).

After a predetermined time depending on the strength of the twist and the thickness of the yarn, the supply of compressed air into the shield 51 is stopped, and the roller pair 2, 20 is moved to the fixedly held and prepared yarn end F'. It is also swung in front of the opening of the yarn draw-off tube 11 of the open-end spinning device (positions in FIGS. 3 and 4). Due to the negative pressure present in the spinning device, the yarn end F' is drawn into the yarn withdrawal tube 11 and, after leaving the roller pair 2, 20, finally reaches the fiber collecting surface 6 of the spinning device, where it is It is joined to the supplied fiber ring.

In the second embodiment, in order to prepare the free end of the yarn, the roller pair 2, 20 is associated with an intake air nozzle 7, which is followed by a tubular shield 51, which is connected to the oscillation of the roller pair 2, 20. It is within the range of motion (Figure 5).

Using a suction air nozzle, yarn preparation can be done economically. This is because the suction air is necessary for various maintenance operations and is therefore also freely available for thread preparation. Intake air nozzle 7
may be integrally formed with the shield 51 or may be removably coupled. shield 51
is arranged by the holding part 50 in the direction in which the thread F comes out from the roller pair 2, 20,
and is connected to the suction conduit 53.

The suction conduit 53 is preferably connected to a suction device which creates a negative spinning pressure, so that the intake air flow guided by the shield 51 corresponds to the negative spinning pressure during rotor spinning and typically has a water column of 700 mm. be.

The suction air nozzle 7 has at least one auxiliary air opening 71 as close as possible to the inlet opening for the free yarn end F′, which auxiliary air opening 71 is preferably arranged eccentrically with respect to the bore axis of the suction air nozzle 7. It communicates with this intake air nozzle tangentially to the inner diameter (FIG. 7). Four auxiliary air openings 71 arranged offset from one another in the advantageous configuration shown
are distributed around the circumference of the intake air nozzle 7, and these auxiliary air openings are all eccentric to the bore axis of the intake air nozzle 7 and communicate with this nozzle in the connecting direction relative to the inner diameter. There is. In this case, it is important to arrange the auxiliary air openings 71 as follows. That is, a torsional flow component is superimposed on the turbulent air flow formed by the intake air nozzle 7 and guided by the shield 51, and this component follows the spinning twist of the yarn end to be prepared and Prevents twisting back. The auxiliary air opening 71 is simply made by providing a channel-shaped cutout or slit in the free end of the nozzle wall surrounding the inlet opening.

The introduction of the free end of the yarn into the suction air nozzle 7 and the subsequent shield 51 is achieved through an inlet opening 81 arranged in the wall of the suction air nozzle 7 from above concentrically with the eyelid 8.
It is done through. The lid 8 is the intake air nozzle 7
The intake air nozzle 7 is removably attached to and can therefore be removed.
and shield 51 are accessible for maintenance work. Additionally, the arrangement of the inlet opening 81 in the lid simplifies the manufacture of the device. When using a lid that fits onto the wall of the intake air nozzle from above, each auxiliary air opening 71 is connected to the outside air via a bypass 72. The suction of the free yarn end to be prepared into the suction air nozzle 7 and the shield 51 is facilitated by the funnel-shaped inlet opening enlargement shown in FIG. In order to create a relatively strong turbulent air flow, the flow cross-section of the yarn free end inlet opening 81 is smaller than that of the auxiliary air opening. When using a negative spinning pressure of 700 mm water column for yarn preparation, an inlet opening 8 with a diameter of 2 to 5 mm, depending on the yarn thickness.
1 will be provided. These dimensions have been found to be particularly advantageous in the given situation.

For the spinning start of the rotor-spinning device, it is advantageous to provide a free yarn end with a length approximately equal to the diameter of the spinning rotor. Also here, the inner wall 52 of the shield 51
Preparation is facilitated by providing at least one protrusion or roughened surface extending in the longitudinal direction of the shield and having sharp edges (FIG. 5). 6th
In the configuration shown, the shield 51 is formed as a sleeve, the inner wall of which has projections or roughened surfaces with sharp edges. shield 51
is clamped by a cap nut 91 in the holder 9 of the intake air nozzle 7, which in this embodiment is designed as a clamping bush. After loosening the cap nut 91, the shield 51 is movable axially as indicated by the double-headed arrow, so that, depending on the length of thread to be prepared, sharp edge protrusions or rough surfaces may be whip-like due to the turbulent intake flow. It can be moved to the range of the vibrating thread end. that time
For an intake flow corresponding to a spinning negative pressure of 700 mm water column,
According to the knowledge so far, the inner diameter of the shield 51 is 8
A range of 15 mm to 15 mm allows optimal preparation of the free end of the thread.

In contrast to the processing method in the first embodiment, according to FIG.
The thread F, which is gripped by the thread F, may be cut only after the roller pair 2, 23 has been swung above the inlet opening 81 of the suction air nozzle 7 and the thread has thereby been extended from the thread receiving position to above the preparation device. Conceivable. The cutting is performed by a blade 15 cooperating with an anvil roller 16, which is
It is arranged at a predetermined distance from the intake air nozzle 7 (FIG. 5). The severed thread end is sucked out by means of a suction tube 14, while at the same time a pair of rollers 2, closely positioned in front of the funnel-shaped enlargement,
The free end F' of the thread, held fixed by the thread 20, is sucked through the inlet opening 81 into the suction air nozzle 7 and into the shield 51, into which the valve is opened just before the thread is brought to a predetermined length. Intake air is introduced. The resulting turbulent suction flow causes the free yarn end F' to vibrate like a whip, so that the fiber ends are spread out from the yarn surface and the yarn has a rough surface.

In this case, as mentioned above, the strength of the yarn ends is maintained because the spinning is maintained at the yarn ends. Here too, the preparation of the yarn end F' is done by shield 5.
This is carried out very quickly by striking the yarn end against the rough inner surface 52 of the thread.

When the thread end preparation is finished after a predetermined time,
The intake air supply is stopped. The prepared yarn free end is then inserted into the spinning device to facilitate its insertion into the spinning device.
For example, by driving the spool S in the winding direction and rewinding a predetermined length of thread onto the spool S, the length suitable for insertion may be made. At this time, the roller pair 2, 20 together with the yarn end prepared at this time is swung to the yarn discharge position in front of the opening of the yarn withdrawal tube 11 (FIG. 1).
The yarn end is now drawn into the yarn withdrawal tube 11 due to the negative pressure present in the spinning device. After the predetermined length of yarn returned onto the spool S is fed out again into the yarn withdrawal tube 11, the free yarn end is released from the roller pair 2, 20 and reaches the fiber collecting surface of the spinning device;
Here it is joined to the supplied fiber ring.

The device described above can be modified and improved in various ways. For example, the shield 51
A longitudinal slit may be provided for passing F′.
Depending on the location, the shield 51 may be arranged transversely to the direction of thread exit from the roller pairs 2, 20 or other thread holding devices, such as thread clamps. Furthermore, instead of the stationary shield 51, a movable shield may be provided, which serves to approach the free yarn end F' and at the same time to guide it into the yarn withdrawal tube 11. In this case, the shield has a longitudinal slot in the direction of movement of the yarn towards the spinning device, so that the yarn extending into the spinning device is released during the return movement of the shield to its initial position. It is also clear that such a yarn end preparation device according to the invention can be fixedly arranged at the respective spinning position.

[Brief explanation of drawings]

1 is a diagram showing the yarn joining device during the joining process at the spinning position; FIG. 2 is a longitudinal sectional view of a shield with a compressed air nozzle arranged within the swing range of the yarn holding device; 4 is a side view showing the individual steps of preparing the yarn end and transferring it to the spinning device; FIG. 4 is a plan view showing the individual steps of FIG. 3; FIG.
The figure shows, partially in section, a shield with an intake air nozzle arranged in the swing range of the yarn holding device;
FIG. 6 shows an enlarged, partially sectional view of the intake air nozzle with a shield formed as a sleeve, and FIG. 7 shows a cross-sectional view of the intake air nozzle of FIG. DESCRIPTION OF SYMBOLS 1... Spinning machine, 2, 20... Roller pair, 5... Compressed air nozzle, 7... Suction air nozzle, 8... Lid, 9...
Holding part, 10... Casing, 11... Yarn drawing pipe,
12... Pull-out roller pair, 13... Thread winding device, 14
... Suction pipe, 51... Shield, 52... Inner wall, 53...
Suction conduit, 71...auxiliary air opening, 72...bypass, 81...inlet opening.

Claims (1)

[Scope of Claims] 1. The yarn end is sucked into a suction pipe, cut to a predetermined length that can be spliced, and the yarn end cut to a predetermined length for splicing in an open-end spinning device. In the yarn splicing method for preparation, a turbulent twisted airflow is formed by a tubular shield having at least one nozzle separate from the suction pipe, and the free end of the yarn held fixed after being cut into a predetermined length is turbulent. Exposing the yarn end to a torsional air current causes the yarn end to vibrate like a whip, exposing the individual fiber ends at the yarn end and spreading them out from the yarn surface, and the yarn end thus prepared is subsequently made into an open end. A method for preparing yarn ends cut to length for splicing on an open-end spinning device, characterized in that the yarn ends are conveyed to a fiber collection surface of the spinning device. 2. Extending the yarn to be prepared for splicing from the yarn receiving position to a point beyond the preparation device, and then cutting it to a predetermined length, and then sucking the yarn free end thus formed into the preparation device. , the method according to claim 1. 3. The method according to claim 1, wherein the free end of the thread is struck against the edge-like protrusion. 4. The method according to claim 1, wherein the free end of the yarn is struck against a rough surface. 5. A method according to one of claims 1 to 4, characterized in that a yarn end is prepared with a length greater than the staple length. 6. When preparing the thread, start from the free end to the staple length.
6. The method according to claim 5, wherein the objects are held fixed at intervals of 1.5 times. 7. Method according to claim 5, characterized in that a free end of the yarn is provided with a length approximately equal to the diameter of the spinning rotor. 8 It has a yarn holding device that holds the yarn at a distance from the end, sucks the yarn end through a suction pipe, cuts it to a predetermined length that can be spliced, and uses it for splicing in an open-end spinning device. In this device, a tubular shield 51 is provided near the thread holding devices 2 and 20 in addition to the suction pipe 14, and this tubular shield is An open air system characterized in that it is provided with at least one compressed air nozzle 5 or suction air nozzle 7, which generates a turbulent torsional air flow that causes the fixedly held thread end F' to vibrate like a whip. A device that prepares yarn ends cut to a predetermined length for splicing in an end spinning device. 9. Device according to claim 8, characterized in that at least one edge-like projection is provided in the region of the vibrating thread end F'. 10. Device according to claim 8, characterized in that a roughened surface is arranged in the region of the vibrating yarn end F'. 11. Device according to claim 8, in which the compressed air nozzle 5 is directed towards the inner wall 52 of the shield 51. 12. The device of claim 11, wherein the compressed air nozzle (5) is oriented into the shield (51) at an acute angle α to the center line of the shield. 13. A plurality of compressed air nozzles 5, 5' open into the shield 51, the openings of these nozzles facing each other, and the nozzles operating in an alternating order. 1
The device according to item 2. 14. The device according to claim 8, wherein the shield 51 is connectable to the suction conduit 53. 15. The device according to claim 8, wherein the intake air nozzle 7 has one or more auxiliary air openings 71 after the inlet opening 81 for the free yarn end F', viewed in the flow direction. 16. Device according to claim 15, characterized in that the auxiliary air opening (71) opens into the intake air nozzle (7) eccentrically with respect to the bore axis of this nozzle. 17. The device according to claim 16, wherein the auxiliary air opening 71 opens into the intake air nozzle 7 tangentially to the inner diameter of this nozzle. 18. Claim 1, wherein the auxiliary air opening 71 is formed by a groove-shaped cutout in the nozzle wall.
Apparatus according to one of clauses 5 to 17. 19 The flow cross-sectional area of the inlet opening 81 is smaller than that of the auxiliary air opening 71.
Apparatus according to one of clauses 5 to 18. 20. Device according to claim 19, characterized in that the diameter of the inlet opening 81 for the free yarn end F' is between 2 and 5 mm, depending on the thickness of the yarn. 21. The device according to one of claims 15 to 20, wherein the inlet opening 81 is arranged in the wall of the intake air nostle 7 from above in the eyelid 8. 22. Claims 15 to 2, in which the inlet opening 81 has a funnel-like enlargement on which the thread holding device 2, 20 can be positioned closely.
1. Device according to one of clauses 1 to 1. 23 Four auxiliary air openings 71 arranged offset from one another are distributed over the circumference of the intake air nozzle 7 and each auxiliary air opening 7
23. Device according to one of claims 15 to 22, wherein 1 is connected to outside air via a bypass 72. 24. Device according to claim 8, in which the intake air nozzle 7 is connected to the intake conduit 53 via a shield 51. 25. Device according to claim 24, characterized in that the suction conduit 53 is connected to a suction device which creates a spinning negative pressure. 26. The device according to claim 24, wherein the intake air nozzle 7 is formed integrally with the shield 51. 27. The device of claim 8, wherein the shield 51 has a longitudinal slit. 28. Device according to claim 27, in which the shield 51 has a slit in the direction of movement of the yarn into the spinning device. 29. The device according to claim 8, wherein the shield 51 is a square tube. 30. Apparatus according to claim 8, wherein the yarn holding device 2, 20 is movable between a yarn receiving position and a position for delivering the yarn end to a fiber collection surface of an open-end spinning device. 31. The device according to claim 30, wherein the shield 51 is fixedly arranged within the swing range of the thread holding devices 2, 20. 32. The device according to claim 8, wherein the inner diameter of the shield 51 is in the range of 8 to 15 mm.