CH718245A1 - Method for piecing and piecing device on a ring spinning machine. - Google Patents

Abstract

In a piecing method, a piecing device (2) on a ring spinning machine (1) with a large number of spinning positions (13) at which a roving (6) emerges from delivery rollers (7) of a drafting system (5) and with a runner (9) and a rotating cop (11) is turned into a thread (10) and wound onto the cop (11), the piecing device (2) automatically generates a thread breakage in which a thread end (14) with the from the delivery rollers (7) exiting roving (6) and the spinning process is then continued. Optionally, according to procedure a) the thread end (14) of the broken thread (10) is searched for, the found thread end (14) is recorded and used for piecing in order to obtain a cop (11) without thread interruption or according to procedure b) an auxiliary thread (17 ) from a supply of thread (16) attached to the cop (11), then this auxiliary thread (17) is separated to obtain a thread end attached to the cop (11) and this thread end is used for attachment to a cop (11) obtained with a thread break. Depending on the utilization of the attachment device (2) and / or the probable prospect of success of procedure a), it is selected whether the thread end (14) is provided according to procedure a) or b), it being assumed that procedure a) more Takes more time than procedure b).

Description

TECHNICAL AREA

The present invention relates to a piecing method of a piecing device on a ring spinning machine with a large number of spinning positions at which a roving emerges from delivery rollers of a drafting system and is twisted into a thread with a runner and a rotating cop and wound up on the cop the piecing device automatically starts a piecing in the event of thread breakage, in which one thread end is connected to the roving emerging from the feed rollers and the spinning process is then continued, and the thread end of the broken thread is searched for according to procedure a), the thread end found is recorded and used for piecing , in order to obtain a cop without thread breaks or according to procedure b) an auxiliary thread from a thread supply is attached to the cop, then this auxiliary thread is separated in order to obtain a thread end attached to the cop and this thread end is used for attachment to a cop wed t to obtain a thread break, as well as a corresponding piecing device.

TECHNOLOGICAL BACKGROUND

[0002] DE 2 351 312 A1 discloses a piecing device which is equipped with devices for carrying out two different piecing processes. On the one hand, the attachment device can look for a thread end on the cop and connect it to the fiber composite in the drafting system. On the other hand, it can also attach the thread with an auxiliary thread, which is placed on the cop and then fed to the drafting system. She primarily tries to carry out the piecing process in which the end of the broken thread is searched on the cop and attached using this thread end. Only if this method cannot be carried out is a thread thrown onto the cop and attached with this thread according to the second procedure described.

This ensures that the repair of a thread break does not fail because the end of the thread cannot be found on the cop and that a thread break in the winding of the cop is only present if the thread break could not have been repaired in any other way .

The disadvantage here, however, is that the procedure described is very time-consuming. The first attempt is always to find the end of the thread on the bobbin. Only when this attempt fails is an auxiliary thread used to repair the thread breakage. As a result, the piecing device is tied to the respective spinning position for a very long time. Other spinning stations that need the piecing device for piecing a thread are not productive in the meantime.

PRESENTATION OF THE INVENTION

The object of the present invention is to eliminate the disadvantages known from the prior art, in particular to improve the productivity of a ring spinning machine.

The object is achieved by a method for piecing and a piecing device having the features of the independent claims.

Proposed is a piecing method of a piecing device on a ring spinning machine with a plurality of spinning positions, where a roving emerges from delivery rollers of a drafting system and is rotated with a runner and a rotating cop into a thread and wound on the cop. In the event of thread breakage, the piecing device automatically generates a piecing in which one thread end is connected to the roving coming out of the delivery rollers. The spinning process is then continued. Optionally, according to procedure a), the thread end of the broken thread is sought, the thread end found is recorded and used for piecing in order to obtain a cop without a thread break. Alternatively, according to procedure b), a thread end of an auxiliary thread from a thread supply is attached to the cop, then this auxiliary thread is separated in order to obtain an additional thread end attached to the cop and this additional thread end is used for piecing. A cop with a thread break is thus obtained. Procedure a) produces a higher-quality cop, since it does not contain any thread breaks and, accordingly, further processing on a winding machine can also take place without any breaks. However, piecing according to procedure a) is more time-consuming for the piecing device, since the end of the thread has to be sought and found somewhere on the cop. The success rate with procedure a) is also lower than with procedure b), since it can happen that the end of the thread on the cop is only found after a long time or not at all.

Depending on the utilization of the piecing device and / or the likely prospect of success of procedure a) is selected accordingly, whether the thread end is provided according to procedure a) or b). If it is assumed that procedure a) takes more time than procedure b), the piecing device can be operated particularly effectively with the method according to the invention. A compromise is thus obtained between the productivity of the ring spinning machine and the quality of the cops. It is assumed that a cop of higher quality is a cop without a yarn break. In principle, attempts are therefore made to obtain the best possible quality of the bobbins. This good quality is expected from a piecing, in which the thread end is picked up by the cop and brought to the drafting system of the ring spinning machine for connection with the sliver located therein (procedure a). This creates an uninterrupted thread on the cop. A cop without extraneous thread or without a thread break is considered to be the higher-quality cop. However, if an attempt were made to always attach according to this procedure a), the productivity of the ring spinning machine would suffer as a result, since this procedure takes a long time and also generally involves higher risks with regard to the success of a piecing. Accordingly, the invention proposes that, under certain conditions, not procedure a) but procedure b) is selected in order to produce a piecing. The decision is therefore made as to whether procedure a) is used and thus a higher-quality cop is obtained, or whether procedure b) is used and thus a somewhat less high-quality cop is obtained, but quick completion of the appointment order is reached. According to the invention, this decision depends on the capacity utilization of the attachment device and/or on the probable prospect of success of procedure a). The production quantity of the ring spinning machine can thus be optimally controlled in relation to the production quality of the bobbins.

If the piecing device is heavily used, i. H. if, for example, there are already requests from a number of other spinning positions at which a yarn breakage is to be repaired, an attempt is made to select procedure b) if possible in order to increase the productivity of the ring spinning machine, since this allows the piecing device to complete the pending work in a shorter time. Accordingly, the individual spinning stations are also idle for a shorter time than if the more time-consuming procedure a) were carried out at each spinning station and the piecing device required a longer time until all the work to be carried out beforehand was completed. However, the bobbins produced on the ring spinning machine with a piecing according to procedure b) will have a thread interruption in the region of the piecing with the auxiliary thread.

[0010] The same selection is also made if the probable chance of success for procedure a) is low. This can be the case, for example, if a critical yarn is spun at the spinning station, which is problematic for finding the end of the yarn on the cop. Another reason can also be that the device required for the procedure for finding the end of the thread on the cop is not operational or not fully operational. In this case, too, it is advantageous if, instead of attempting procedure a), procedure b) is selected immediately, at least until the faulty device required for finding the thread end has been repaired. In favor of the productivity of the ring spinning machine, it is accordingly accepted that cops are produced with a thread interruption in the region of the piecing. The ring spinning machine can thus be operated as effectively as possible in this sense.

The inventive method accordingly has the advantage that the productivity of the ring spinning machine can be significantly increased because the piecing device is able to select either procedure a) or procedure b) as the preferred procedure for eliminating a piecing. This selection takes into account which procedure a) or b) the ring spinning machine can use to produce the highest possible quality of the bobbins or the highest possible number of bobbins without yarn breaks with the highest possible productivity. On the one hand, an attempt is made to obtain a particularly high-quality piecing, as is possible with procedure a), when sufficient time is available, for example because the piecing device is not required at any other spinning station. However, since this procedure a) is very time-consuming compared to procedure b), it is attempted in favor of the productivity of the ring spinning machine that downtimes at the individual spinning positions are kept as short as possible and accordingly the piecing device tries to move the individual spinning positions as quickly as possible at the expense of the quality of the bobbin to be productive again. In time-critical situations of the ring spinning machine, the procedure b) for attaching a new thread to the requesting spinning position of the ring spinning machine is accordingly selected without previous procedure a) immediately.

It also has advantages if the procedure a) is chosen when the cop is to be produced without thread breaks or when a predetermined number of thread breaks are already present on the cop. So if, if possible, particularly high-quality cops are to be produced without a thread break, procedure a) for preparing a thread break is tried first. Regardless of the longer processing time, attention is paid to the quality of the bobbin. The same can also be advantageous if the required quality of the cop allows a predetermined number of thread breaks on the cop, but a number which exceeds this predetermined number is no longer accepted. In this case, the optional method of the present invention is operated until this predetermined number of thread breaks is allowed. Subsequently, the first attempt is always to use procedure a) successfully.

It is advantageous if the procedure b) is selected when the number of spinning stations waiting for the piecing device exceeds a predetermined number. If there are thread breaks at this predetermined number of spinning positions and the corresponding spinning position can therefore not produce any more thread, the faster procedure b) is then selected until the limit value of the predetermined number of spinning positions is fallen below again. Thereafter, the optional procedure a) or b) according to the invention is continued.

It is also advantageous if the procedure b) is selected when the yarn spun on the spinning station exceeds a predetermined yarn count. If the predetermined yarn count is exceeded, i.e. the yarn is very fine, experience has shown that it is more difficult to find the end of the yarn on the cop. Longer times must therefore be allowed for before the end of the thread is usually found, or it can even be assumed that the end of the thread very often cannot be found at all. In this case, it is advantageous to choose the safer procedure b), so that the piecing device is not held up too long at the individual spinning positions.

[0015] It also has advantages if procedure b) is selected if the elimination of the thread breakage by means of procedure a) was not successful. In order to obtain high-quality bobbins without thread breaks inside the bobbin, it is advantageous if procedure a) is tried first. Procedure b) is only used if procedure a) is unsuccessful.

It is advantageous if procedure b) is chosen when a device for searching for the thread for procedure a) is not functional. Such a device for searching for the thread can be, for example, a suction nozzle which searches the surface of the cop for the end of the thread. Such suction nozzles are usually also designed to be movable. If, for example, the drive of the suction nozzle has failed, the piecing device can still be used because it can continue to carry out piecing processes using procedure b) and the productivity of the ring spinning machine does not decrease and the quality of the cops produced decreases only slightly.

There are also advantages if the selection of the procedure a) or b) is made by a control device of the spinning machine or by an operator. The control devices can process information from the status of all spinning positions of the ring spinning machine and select the most productive procedure a) or b) for the piecing device. A manual setting of the preferred procedure a) or b) by an operator can also be advantageous, in particular if the operator determines that certain devices of the attachment device are not functional.

It is advantageous if, in procedure a), the thread end of the broken thread is searched for on the cop or at a predetermined location on the spinning station. In the case of procedure a), it is necessary for the thread end of the cop to be grasped. In order to be able to find the thread end of the cop as quickly as possible, it is either searched for on the surface of the cop. Alternatively, a predetermined location can also be provided at the spinning station in order to find the thread end as quickly as possible. For example, if the spinning process is deliberately interrupted, the thread end can be stopped at the spinning station before it reaches the bobbin and picked up again at this point by the piecing device.

[0019] It also has advantages if the thread end is drawn into the runner and/or into a thread guide. The attachment device is preferably able to thread the thread end from the drafting system or from the auxiliary thread supply, which carries the auxiliary thread, through the runner and/or the thread guide of the spinning station.

It is also advantageous if the cop is marked as to whether it has piecings according to procedure a) and/or b) and/or what length of thread is wound on the cop between two thread breaks. Such a marking can be done, for example, by a data carrier which is connected to the cop. Whether or how many piecings according to procedure a) or procedure b) are contained on the cop can be recorded on the data medium. The information about the length of the thread between two thread interruptions on the cop can be recorded on the data carrier. This is advantageous for the further processing of the bobbin on the following winding machines. The data carrier can be designed to be electronically or optically readable, for example with labels that can be read by an operator, but it is also possible to connect the data carrier to the cop. The identification can be done directly or indirectly on the cop. For example, the data carrier can be attached to the cop itself or to a means of transport for the cop on which the cop is arranged. The data can also be recorded directly or indirectly on the data carrier. It is thus possible, on the one hand, for the data carrier to have the corresponding information directly, ie itself. Indirectly, however, it is also possible for the cop to have a fixed, consistent identification, for example a number, and for this number to be linked in a database with the corresponding information on procedures a) or b) or the lengths of the individual thread sections.

Advantageously, the selection of the procedure a) or b) is based on empirical values in a further processing of comparable threads and / or cops on a subsequent preparation station and / or winding machine. For example, during further processing it can be determined that there is a maximum of a certain number of thread breaks on the cop or in the batch (e.g. max. 3 thread breaks or foreign threads per cop or max. 120 thread breaks or foreign threads per batch). allowed, otherwise the efficiency of the winding machine is significantly reduced. Through this experience, with a comparable thread or cop on the ring spinning machine, the maximum number of permissible thread breaks, i. H. piecing according to procedure b). The efficiency of the winding machine can be reduced, for example, by the fact that the preparation of the thread end takes too much time.

If, in an advantageous embodiment of the invention, the successful implementation of procedure a) and/or b) is stored in a data memory and the probable prospect of success of procedure a), in particular with regard to a specific batch, is determined from this, this can also Selection of the procedure a) or b) can be specified. If there is a high prospect of success of procedure a) with the thread of the corresponding lot, procedure a) is used more often and procedure b) is avoided.

If, at the start of a game, the probable prospect of success of procedure a) for this game is advantageously used as the start parameter and/or updated while the game is running and saved in an updated form at the end of the game, then the experiences that have already been made with regard to this game or this thread can other spinnings were made to be used first. If, in the course of further games, new findings and experiences regarding the chances of success of procedure a) arise, this empirical value is also updated and saved and can serve as a starting parameter for the next game. This has the advantage that the probable limits of procedure a) can already be applied at the start of a game. The efficiency of the ring spinning machine can thus be optimized. For example, dynamic optimization can be carried out during ongoing production. If the preparation station/winding machine was able to process the bobbins well despite a relatively large number of foreign threads, the number of permissible foreign threads can be increased and vice versa.

A piecing device according to the invention for producing a piecing on a ring spinning machine has devices a) and b) for automatic piecing in the event of yarn breaks, for connecting a yarn end to a roving.

The device a) has a search and handling device to search for the thread end of the broken thread, to detect the thread end found and to use it for attachment in order to obtain a cop without a thread break. The device b) has a fastening and handling device to fasten an auxiliary thread from a thread supply on a cop, then separate this auxiliary thread to obtain a thread end attached to the cop and use this thread end for attachment to a cop obtained with a thread break. The search and handling device and the fastening and handling device can be implemented in a single structural unit or else in different structural units. According to the invention, the piecing device comprises a control device which is suitable for selecting, depending on the capacity utilization of the piecing device and/or depending on the probable prospect of success of device a), whether the thread end is provided with device a) or device b). As a result, the attachment device can be operated as effectively as possible, it being assumed that device a) requires more time for attachment than device b). The piecing device according to the invention thus contributes significantly to the fact that the efficiency of the ring spinning machine is high and is not reduced by spinning positions that are idle for a long time and have to wait for the piecing device. Depending on whether the quality of the cops to be produced or the productivity of the spinning station requires it, either device a) or device b) of the piecing device is used to carry out the piecing process.

The ring spinning machine is equipped with a variety of spinning positions, where a roving emerges from delivery rollers of a drafting system and is rotated with a runner and a rotating cop into a thread and wound onto the cop. If the piecing is connected according to procedure a) or b) or with device a) or b), the spinning process can then be continued again. The control device can work both automatically according to the specified rules and can also be influenced and switched manually by an operator.

There are advantages if the device a) has at least one suction device. With the suction device, the device a) is able to suck up a thread end on the surface of the cop and to continue to handle it for the piecing process. The suction device can be designed to be movable, for example, in which case it can be moved toward or away from the cop.

It also has advantages if the device b) has an auxiliary spool for the thread supply. The auxiliary thread is stored on the auxiliary spool and is used by device b) for the piecing process as required. The auxiliary thread can be of the same type as the thread itself. However, it can also differ from the thread so that, for example, attachment is simplified or that it can be better distinguished from the normal thread.

Furthermore, it is advantageous if the control device is suitable for evaluating information about the number of requests from the piecing device on the spinning machine. This makes it possible, based on the upcoming piecing processes that the piecing device has to carry out, to decide whether the device a) that works slower but of higher quality or the device b) that works faster but has a lower quality or works differently can be used in order to obtain the desired and permissible relationship between productivity and quality.

It is also advantageous if the piecing device and/or the control device works together with a marking device for marking the cop as to whether it has piecing devices of device a) and/or device b). The marking device marks the cop directly or indirectly, for example by means of its transport carrier. The information can be passed on to a system control in order to be able to transport the corresponding cop to a suitable further processing point.

Are known piecing robots for ring spinning machines that look for the thread end on the cop if possible and thus carry out a piecing. If it is not possible to find the end of the thread, start spinning with an auxiliary thread that is carried along. However, since piecing with auxiliary thread can generally be realized much faster, with general piecing with auxiliary thread significantly more thread breaks can be carried out per unit of time and piecing robot. In a simple embodiment, the operator can choose in which mode (mixed or only with auxiliary thread) the piecing robot is to be operated. However, it is particularly advantageous if, based on the thread breakage position (or utilization of the piecing robot), the machine itself decides in the sense of automatic efficiency optimization when the search process for the thread end should be increased or completely dispensed with.

The device is designed according to the preceding description, with the features mentioned being able to be present individually or in any combination. The piecing device can be manufactured and sold together with a ring spinning machine. However, it is also possible for the piecing device to be manufactured and sold as a separate structural unit and to be attached to an existing ring spinning machine.

BRIEF EXPLANATIONS OF THE FIGURES

Aspects of the invention are explained in more detail on the basis of the exemplary embodiments shown in the following figures and the associated description. There are shown schematically in each case: FIG. 1 a side view of a ring spinning machine and a piecing device; FIG. 2 a cop; FIG. 3 shows a side view of a winding machine; and FIG. 4 shows a sketch of a plan view of a spinning plant.

WAYS TO CARRY OUT THE INVENTION

In the following description of the alternative exemplary embodiments illustrated in the figures, the same reference symbols are used for features which are identical and/or at least comparable in terms of their design and/or mode of operation compared to the exemplary embodiments described above. If these are not explained again in detail, their design and/or mode of action corresponds to the design and mode of action of the features already described above. For reasons of clarity, not all of the same parts are provided with reference symbols, but are drawn in the same way.

Figure 1 shows a side view of a ring spinning machine 1 and a piecing device 2. The piecing device 2 is arranged in a mobile robot 3, which can be moved along the ring spinning machine 1 on rollers 4. The ring spinning machine 1 has a drafting system 5, which draws a roving 6 with pairs of rollers running at different speeds and leaves the drafting system 5 at delivery rollers 7. The drawn roving 6 then runs in a known manner through a thread guide 8 and a runner 9 to finally be wound up as thread 10 on a cop 11 . The cop 11 is set in rotation by a drive 12, as a result of which the rotor 9 circles the cop 11 and thus introduces a rotation into the thread 10 must be scheduled. A thread end 14, which is the end of the thread 10 that is wound onto the cop 11, is sucked into a search and handling device 15 of the attachment device 2 according to this illustration. The thread end 14 was searched for by the search and handling device 15 on the surface of the cop 11 with a suction device, threaded through the runner 9 and the thread guide 8 and is now ready to be attached to the roving 6 . For this purpose, the search and handling device 15 can be pivoted according to the double arrow shown and is also designed to be movable in some other way, for example more linearly. The search and handling device 15 or the piecing device 2 may have further handling elements (not shown) in order to be able to grip the thread end 14 on the cop 11, thread it through the runner 9 and the thread guide 8 and in the drafting system 5 to the roving 6 to create.

The attachment device 2 also includes a fastening and handling device 35 with a supply of thread 16. The supply of thread 16 is arranged in the robot 3 in the form of an auxiliary coil. The thread supply 16 has an auxiliary thread 17 which can be drawn off the auxiliary spool with feed rollers 18 . According to the present exemplary embodiment, the feed rollers 18 make a thread end 14 ′ available to the fastening and handling device 35 . It moves in the direction of the thread end 14' and grasps this thread end 14' in order to carry out a piecing operation. The feed rollers 18 are set in rotation by a control device 19 and remove the necessary length of the auxiliary thread 17 from the thread store 16. The control device 19 also ensures that the search and handling device 15 and the fastening and handling device 35 move accordingly or other handling devices, not shown, of the piecing device 2 in order to be able to carry out a piecing properly.

To attach the thread end 14 'of the auxiliary thread 17, the thread end 14' is placed on the cop 11 and fixed there, for example by a few windings on the cop 11 (see Figure 2). The auxiliary thread 17 runs through the runner 9 and the thread guide 8, is brought into contact with the roving 6 and cut off before or afterward, so that this thread end, which is no longer visible later, forms a piecing together with the roving 6 in the drafting system 5.

The control device 19 supplies signals to the piecing device 2 as to whether the thread end 14 or the thread end 14' is to be used for the piecing. This decision is made depending on the capacity utilization of the piecing device 2 and/or on the probable prospect of success when using the thread end 14 for the piecing. The thread end 14 preferably serves for the piecing, since there is no thread interruption on the cop 11 when piecing is done directly with the thread 10 of the cop 11 and its thread end 14 . The disadvantage here, however, is that finding the thread end 14 on the cop 11 is time-consuming and not always successful. If the piecing device is required for piecing at a number of other spinning positions 13 because there are also thread breaks, it is advantageous according to the present invention if the piecing device 2 selects the faster and safer piecing process with the auxiliary thread 17. In this case, the thread end 14 ′ of the auxiliary thread 17 is gripped at the predefined location of the feed rollers 18 and placed on the cop 11 . This thread end 14' forms an interruption in the thread 10 on the cop 11. This interruption in the thread 10 on the cop 11 leads to an interruption in the winding process during further processing, for example on a winding machine, and can there possibly lead to a deterioration in the efficiency of the winding machine effect. However, this procedure is more favorable for the productivity of the ring spinning machine 1, since the priority should be the better but more time-consuming piecing with the thread end 14, but in order not to unnecessarily impair the productivity of the spinning machine 1, in the event of an unusual workload or if this is foreseeable that the thread end 14 on the cop 11 will be difficult or uncertain to find, resorted to the auxiliary thread 17 with its thread end 14 '.

In order to identify the cop 11 during further processing as a cop 11 which has one or more thread breaks due to the piecing with the thread end 14', or as a cop 11 which has no thread breaks, a marking device 20 is provided. The marking device 20 marks the cop 11, for example by a corresponding marking or labeling of a data carrier 21 (see FIG. 2). As a result, the cop 11 can be subjected to special treatment during further processing, for example, if it has thread interruptions. Such a special treatment can lead to the following machine, for example a winding machine, being able to work as productively as possible despite these thread interruptions.

FIG. 2 shows the cop 11 which is connected to a peg tray 22 . The peg tray 22 is a transport element with which the cop 11 can be transported in the spinning plant. For this purpose, the cop 11 is attached to the peg tray 22 via a sleeve 23 on which the thread 10 is wound. The data carrier 21 is provided to indicate whether or how many thread breaks are on the cop 11 . The data carrier 21, which is shown here as a bar code, for example, can be recognized at corresponding recognition points in the spinning plant and evaluated with regard to the further processing of the cop 11. The data carrier 21 can be attached to the sleeve 23, for example. However, it could also be arranged on the peg tray 22 . In addition to information about the presence of a thread interruption, the data carrier 21 can also provide information about the length of at least one wound thread section on the cop.

A thread end 14'' which rests on the surface of the cop 11 can also be seen in FIG. This thread end 14 ″ forms the end of the complete thread 10 wound onto the cop 11 . Dashed lines, on the other hand, indicate that there is an interruption in the thread on the cop 11 . Accordingly, the thread end 14, which has arisen from the started winding of the cop 11 with the thread 10 due to a thread breakage, is shown. Attaching the auxiliary thread 17 (see FIG. 1) creates another thread end 14' on the cop 11, which is also shown in dashed lines because it is not visible. Since, after attaching the auxiliary thread 17, another thread 10 was wound onto the cop 11, this thread end 14' is now located inside the cop 11. This thread end 14' could also be visible under certain circumstances, for example if it is at a defined position the sleeve 23 has been fixed. As a rule, the thread end 14' and thus the thread break is invisibly located in the cop 11. It is therefore advantageous if the data carrier 21 notes whether or how many thread breaks, ie. H. Thread ends 14 and 14 'are inside the cop 11 are.

Figure 3 shows the sketch of a side view of a winding machine 25. The yarn 10 is wound onto a cross-wound bobbin 26 from the cop 11a arranged on a peg tray 22. Arranged on the winding machine 25 is a suction tube 27 that can be pivoted according to the double arrow and a gripper 28 that can also be pivoted and optionally moved linearly. Only one of a large number of winding units 29 of the winding machine 25 is shown. After a thread breakage, the suction tube 27 can be used to search for and detect a thread end that has been wound up on the cross-wound bobbin 26 . The sketched gripper 28 is also able to look for a thread end 14 of the cop 11a and grasp it after a thread breakage. The two thread ends can then be introduced into a splicing device 30 and connected to one another in a known manner. Yarn breaks can occur during the normal winding process. However, a thread break also occurs when there is a thread break with two thread ends 14 and 14' on the cop 11a. As described above, these two thread ends 14 and 14′ were created when an auxiliary thread 17 was attached to the upstream ring spinning machine 1 . During the subsequent, further spinning of the thread 10 on the ring spinning machine 1, this thread interruption was wound over with the thread 10. However, when the yarn 10 is unwound on the winding machine 25, this interruption in the yarn inevitably leads to an interruption in the winding process. With this thread interruption, the thread end 14' is wound onto the cross-wound bobbin 26 and the thread end 14 remains on the cop 11a. The position of the thread end 14 on the cop 11a is undetermined. The cop 11a is therefore removed from the spinning station 29 and replaced by the cop 11b. In the case of the cop 11b, the thread end 14'' lying on the outside of the cop 11b has been placed in a defined position in a preparation station and can therefore be picked up quickly by the gripper 28.

The figure 3 shows different variants of Kopsen 11a to 11d. While the cop 11a is currently being unwound and the two thread ends 14 and 14' are still inside, the following cop 11b has the thread end 14" in a defined position on its outer circumference. Inside the cop 11b are two thread interruptions Accordingly, there are two thread ends 14 and two thread ends 14' inside the cop 11b. In contrast, the cop 11c has no thread breaks whatsoever the cross-wound bobbin 26. Finally, in the cop 11d there is again a thread interruption with a thread end 14 and a thread end 14'.

In Figure 4 is a sketch of a plan view of a spinning plant 40 is shown. According to the present exemplary embodiment, a ring spinning machine 1 is shown in the spinning plant 40 . Of course, several ring spinning machines 1 can be present in the spinning plant 40 . The ring spinning machine 1 has a large number of spinning stations 13 . The robot 3 with its piecing device 2 (see FIG. 1) patrols along the ring spinning machine 1 and, if necessary, carries out piecing processes at the corresponding spinning positions 13. The finished cop 11 produced on the spinning station 13 is then transferred to a transport device 41 which transports the cop 11, optionally on a peg tray 22, to a preparation station 42. In the preparation station 42, the exposed thread end is searched for with a thread search device 43 and deposited at a defined point on the cop 11. The cop 11 is then transported further on the transport device 41 to one of several winding machines 25 . As soon as a yarn breakage occurs when the cop 11 is being rewound onto a cheese 26 at the winding unit 29, the cop 11 is removed from the winding unit 29 and fed back to the preparation station 42. The thread end 14" of the thread break that is now exposed can be searched for again and laid down again at the defined point on the cop 11. This now only partially wound cop 11 is again fed to a winding station 29 of one of the winding machines 25.

The bobbins 11, which are transported on the transport device 41, are marked in order to record the number of known thread interruptions, which were caused by piecing operations with auxiliary thread 17 on the ring spinning machine 1. This identification of the cop 11 is read with a detection device 44 and communicated to a system controller 45 . The system control 45 is connected to all the essential facilities of the spinning system 40 . The cop 11 can be identified, for example, in the form of an optically readable code, for example a bar code or pixel code, or in the form of a data carrier connected to the cop 11, which has been correspondingly electronically inscribed and is readable. However, the identification of the cop can also take place in that the auxiliary thread 17, with which the piecing was made inside the cop 11, is different from the normal thread 10 for the rest of the winding. It is also possible that a consistent identification of the cop 11, for example a number of the cop 11, is linked to data in a database, for example in the system controller 45, in which the information about this cop 11 is stored.

A transport controller 46 is instructed via the system controller 45 that the correspondingly recognized cop 11 is fed to a specific winding machine 25 or a specific winding unit 29 via a transport track 47 . A cop 11, which contains one or even several known thread breaks, is preferably fed to a winding machine 25 or winding station 29, which is in the vicinity of the preparation station 42. Since with such cops 11 with known yarn breaks it can be safely assumed that they have to be fed back to the preparatory station 42, this control of the cop 11 has the effect that the return transport path from the winding unit 29 to the preparatory station 42 can be kept as short as possible . These short transport distances for cops 11, which are likely to have to be transported to the preparation station 42 more frequently, enable the prepared cop 11 to be resupplied more quickly to a winding station 29. In contrast, bobbins 11 that have at least no known yarn breaks are transported to winding stations 29 of winding machines 25 or winding machines 25 that are further away from the preparation station 42, since it is assumed with these bobbins 11 that they are not, or at least need not be safely routed back to the preparation station 42. Overall, the process sequences are thus shortened and accelerated, as a result of which all cops 11 present can be processed more quickly.

Depending on the utilization of the winding machines 25 or winding units 29, bobbins 11 with at least one additional, known thread interruption can be fed to a parking position 48 or treated with priority over other bobbins 11. During the start-up of the winding machine 29 after a changing operation on the ring spinning machine 1, all winding positions 29 of the winding machine 25 must be supplied with cops 11 as quickly as possible. There one would like to avoid bobbins 11, which have to be replaced again after a short running time, because they have an additional, known thread interruption and thus load the preparation station(s) 42 additionally. Such cops 11 are therefore preferably fed to the parking position 48 in order not to impede the other cops 11 . When all winding units 29 are running and there are enough prepared cops 11 in the system, you can preferably take care of the cops 11, which have an additional, known thread break. Depending on the phase or utilization of the winding machines 25, such cops 11 are given priority or are neglected.

Even if there are several preparation stations 42 in a spinning plant 40, the plant controller 45, after recognizing the number of thread breaks in a cop 11, can determine to which preparation station 42 the cop 11 is preferably to be transported. It can be provided, for example, that certain preparation stations 42 are particularly specialized in the search for thread ends 14', which were originally inside the cop 11 and are therefore more difficult to find than the thread end 14", which is on the outer circumference of the finished cop 11 is located after leaving the ring spinning machine 1. Such a special treatment can consist, for example, in stronger or longer suction of the cop 11 in order to be able to find this more difficult thread end 14″ better. The preparation station 42 specialized in this way does not block cops 11 whose thread end 14" can be found more quickly and easily. Cops 11 with known thread breaks can thus be fed to predetermined preparation stations 42 and/or predetermined winding machines 25 or winding stations 29.

The present invention is not limited to the illustrated and described embodiments. Modifications within the scope of the patent claims are just as possible as a combination of the features, even if they are shown and described in different exemplary embodiments.

NAME LIST

1 ring spinning machine 2 piecing device 3 robot 4 roller 5 drafting system 6 roving 7 delivery rollers 8 thread guide 9 runner 10 thread 11 bobbin 12 drive 13 spinning position 14 thread end 15 search and handling device 16 thread store 17 auxiliary thread 18 conveyor rollers 19 control device 20 identification device 21 data carrier 22 peg tray 23 tube 25 winding machine 26 cheese 27 suction tube 28 gripper 29 winding station 30 splicing device 35 fastening and handling device 40 spinning plant 41 transport device 42 preparation station 43 yarn search device 44 detection device 45 plant control 46 transport control 47 transport track 48 parking position

Claims (19)

1. A piecing method of a piecing device (2) on a ring spinning machine (1) with a plurality of spinning positions (13) at which a roving (6) emerges from delivery rollers (7) of a drafting system (5) and with a runner (9) and a rotating cop (11) is turned into a thread (10) and wound onto the cop (11), wherein the piecing device (2) automatically produces a piecing in the event of thread breakage, in which a thread end (14, 14') is connected to the roving (6) emerging from the delivery rollers (7) and the spinning process is then continued, and optionally according to - Procedure a) the thread end (14) of the broken thread (10) searched, the found thread end (14) is detected and used for piecing to obtain a cop (11) without thread break or - procedure b) an auxiliary thread (17) from a thread supply (16) is attached to the cop (11), then this auxiliary thread (17) is separated to obtain a thread end (14') attached to the cop (11) and this thread end (14') is used for piecing in order to obtain a cop (11) with a thread break, characterized in that depending on the utilization of the attachment device (2) and / or on the probable prospect of success of procedure a), whether the thread end (14, 14 ') is provided according to procedure a) or b), it being assumed that the procedure a) takes more time than procedure b). 2. Attachment method according to the preceding claim, characterized in that procedure a) is selected if the cop (11) is to be produced without thread breaks or if a predetermined number of thread breaks are already present on the cop (11). 3. Attachment method according to one of the preceding claims, characterized in that procedure b) is selected if the number of spinning positions (13) waiting for the attachment device (2) exceeds a predetermined number. 4. Attachment method according to one of the preceding claims, characterized in that procedure b) is selected if the thread (10) spun on the spinning station (13) exceeds a predetermined yarn count. 5. Attachment method according to one of the preceding claims, characterized in that procedure b) is selected if the elimination of the yarn breakage using procedure a) was not successful. 6. Attachment method according to one of the preceding claims, characterized in that procedure b) is selected if a device for searching for the thread (10) for procedure a) is not functional. 7. Attachment method according to one of the preceding claims, characterized in that the selection of procedure a) or b) is made by a control device of the spinning machine or by a system control (45) or by an operator. 8. Attachment method according to one of the preceding claims, characterized in that in procedure a) the thread end (14) of the broken thread (10) is sought on the cop (11) or at a predetermined location on the spinning station (13). 9. Attachment method according to one of the preceding claims, characterized in that the thread end (14, 14') is drawn into the runner (9) and/or into a thread guide (8). 10. Attachment method according to one of the preceding claims, characterized in that the cop (11) is identified as to whether it has piecings according to procedure a) and/or b) and/or the length of the thread (10) between two thread breaks on the cop ( 11) is wound up. 11. Attachment method according to one of the preceding claims, characterized in that the selection of procedure a) or b) is based on empirical values during further processing of comparable threads (10) and/or bobbins (11) on a subsequent preparation station (42) and/or winding machine ( 25) is done. 12. Attachment method according to one of the preceding claims, characterized in that the successful implementation of procedure a) and/or b) is stored in a data memory and the probable prospect of success of procedure a), in particular with regard to a specific batch, is determined therefrom. 13. Scheduling method according to one of the preceding claims, characterized in that at the start of a game, the probable prospect of success of procedure a) of this game is used as a start parameter and/or is updated while the game is running and is saved as an updated version at the end of the game. 14. Piecing device for producing a piecing on a ring spinning machine (1), the piecing device (2) having devices a) and b) for connecting a thread end (14, 14') to a roving (6) and wherein the device a) has a search and handling device (15) in order to search for the thread end (14, 14') of the broken thread (10), to grasp the thread end (14, 14') found and to use it for attachment, to obtain a cop (11) without thread breaks and the device b) has a fastening and handling device (35) in order to fasten an auxiliary thread (17) from a thread supply (16) on the cop (11), then to separate this auxiliary thread (17) in order to 11) to obtain a fixed thread end (14, 14') and to use this thread end (14') for piecing in order to obtain a cop (11) with a thread break, characterized in that the attachment device (2) comprises a control device (19, 45) which is suitable for selecting, depending on the capacity utilization of the attachment device (2) and/or on the probable prospect of success of the device a) whether the thread end (14, 14') is provided with the facility a) or b). 15. Attachment device according to the preceding claim, characterized in that the attachment device (2) interacts with an evaluation device which is suitable for determining the time and/or the probable prospect of success of device a) and/or device b) for attaching the thread ( 10) to evaluate. 16. Attachment device according to one of Claims 14 to 15, characterized in that the device a) has a suction device. 17. Attachment device according to one of Claims 14 to 16, characterized in that the device b) has an auxiliary spool for the thread supply (16). 18. Attachment device according to one of Claims 14 to 17, characterized in that the control device (19, 45) is suitable for evaluating information about the number of requests from the piecing device (2) to the spinning machine (1). 19. Piecing device according to one of claims 14 to 18, characterized in that the piecing device (2) and/or the control device (19, 45) cooperates with a marking device (20) for marking the cop (11) whether it is piecing the device a) and/or the device b).