CN114717697A - Piecing method and piecing apparatus - Google Patents

Abstract

A piecing method for a piecing device on a ring spinning machine having a plurality of spinning stations, at which a roving emerges from a delivery roller and is converted into a yarn and wound on a cop, produces a piecing in the event of a yarn break, in which the yarn end is connected to the roving emerging from the delivery roller, and the spinning process is continued. Alternatively according to procedure a) the yarn ends of broken yarns are searched for, the found yarn ends are detected and used for the piecing to obtain a cop without yarn interruption, or according to procedure b) an auxiliary yarn from a yarn supply is fastened to the cop and then the auxiliary yarn is detached to obtain a yarn end fastened to the cop and the yarn end is used for the piecing to obtain a cop with yarn interruption. Depending on the degree of capacity utilization of the piecing device and/or the possible prospect of success of procedure a), it is selected whether to provide the yarn ends according to procedure a) or b), assuming that procedure a) takes more time than procedure b).

Description

Piecing method and piecing apparatus

Technical Field

The invention relates to a piecing method for a piecing device of a ring spinning machine having a plurality of spinning stations, at which rovings emerge from delivery rollers of a drafting system, are converted into a yarn and are wound onto a cop by a rotor and a rotating cop; in the event of yarn breakage, the piecing device automatically generates a piecing in which the yarn end is connected to the roving coming out of the delivery roller and then the spinning process is continued and, alternatively according to procedure a), the yarn end of the broken yarn is searched for, the found yarn end is detected and used for piecing, in order to obtain a cop without yarn interruption; or, according to procedure b), an auxiliary yarn from a yarn supply is fastened to the cop, then the auxiliary yarn is separated in order to obtain a yarn end fastened to the cop, and this yarn end is used for splicing in order to obtain a cop with yarn interruption, and the invention relates to a suitable splicing device.

Background

DE2351312a1 discloses a joint device which is equipped with a device for carrying out two different joint methods. In one aspect, the piecing device can search for the yarn end on the cop and attach it to the fiber composite in the drafting system. Alternatively, it may be possible to splice the yarns with an auxiliary yarn that is placed on the cop and then fed into the draw system. It is mainly intended to perform a piecing method in which the end of a broken yarn is searched for on a cop and the end of the broken yarn is pieced by the yarn end. Only when the method cannot be carried out is the yarn thrown onto the cop according to the second procedure described and spliced to it.

This ensures that the repair of the broken yarn does not fail in any case, since the yarn end cannot be found on the cop, and there is a yarn interruption in the winding of the cop only if the broken yarn cannot be repaired in other ways.

However, in this case, the described procedure is disadvantageously very time-consuming. It is always attempted to find the yarn end on the cop first. Only if the attempt fails, the auxiliary yarn is used to repair the yarn interruption. As a result, the piecing devices are bound to the respective spinning stations for a relatively long time. Other spinning stations that require piecing devices to piec the yarn cannot be produced at the same time.

Disclosure of Invention

The object of the invention is to eliminate the disadvantages known from the prior art and in particular to increase the productivity of ring spinning machines.

This problem is solved by a joining method and a joining device having the features of the independent claims.

A piecing method for a piecing device of a ring spinning machine is proposed, which has a plurality of spinning stations at which rovings emerge from delivery rollers of a drafting system and are converted into yarn and wound onto cop using a rotor and a rotating cop. In the event of yarn breakage, the piecing device automatically produces a piecing in which the yarn ends are connected to the roving coming out of the delivery roller. The spinning process then continues. Alternatively, according to procedure a), the yarn ends of the broken yarn are searched for, the found yarn ends are detected and used for the splice, in order to obtain a cop without yarn interruption. Alternatively, according to procedure b), the yarn end of an auxiliary yarn from a yarn supply is fastened to the cop and then the auxiliary yarn is separated so as to obtain another yarn end fastened to the cop and used for splicing. A cop with yarn interruption is thus obtained. This method produces a cop of higher quality because it does not contain any yarn interruption and, therefore, the further processing on the winder can also be carried out substantially without interruption.

The splicing according to procedure a) is more time consuming for the splicing device, since the yarn end has to be searched and found somewhere on the cop. The success rate in procedure a) is also lower than in procedure b), since it may happen that the yarn ends on the cop are only found after a long time or not at all.

Depending on the degree of capacity utilization of the piecing device and/or the possible prospect of success of procedure a), it is accordingly selected whether the yarn ends are provided according to procedure a) or according to procedure b). With the method according to the invention it is possible to operate the joint device particularly efficiently if it is assumed that procedure a) takes more time than procedure b). Therefore, a compromise is obtained between the productivity of the ring spinning machine and the quality of the cop. The higher quality cop is assumed to be a cop without yarn interruption. In principle, an attempt is made accordingly to obtain the best possible quality of the cop. This good quality is desirable for piecing devices in which the yarn end is picked up by a cop and fed to the drafting system of a ring spinning machine for connection with a fiber band located in the drafting system of the ring spinning machine (procedure a). This produces an uninterrupted yarn on the cop. A cop without foreign yarn or without yarn interruption is considered a higher quality cop. However, if one tries to always splice according to this procedure a), the productivity of the ring spinning machine will therefore be impaired, since this procedure takes longer and, in addition, generally involves higher risks in connection with the success of the splicing. The invention therefore proposes that, under certain conditions, not program a) but program b) is selected in order to produce a joint apparatus. Thus, it is decided whether to take over with procedure a) and thus obtain a cop of higher quality or whether to take over with procedure b) and thus obtain a cop of less quality, but with a rapid completion of the preparation sequence. According to the invention, this decision depends on the degree of capacity utilization of the joint device and/or on the possible prospects for the success of procedure a). Therefore, the throughput of the ring spinning machine can be optimally controlled in terms of the production quality of the cop.

If the piecing devices are used in large numbers, i.e. there have been requests for broken yarns from a plurality of other spinning stations to be repaired, for example, it is attempted to increase the productivity of the ring spinning machine as much as possible to select the program b), since this allows the piecing devices to complete the work to be processed in less time. The individual spinning stations are also deactivated correspondingly for a shorter time than when a more time-consuming procedure a) is carried out at each spinning station and the piecing device takes a longer time until all work to be carried out beforehand has been completed. However, the cop produced on a ring spinning machine with a joint according to procedure b) will have a yarn interruption in the area of the joint with the auxiliary yarn.

The same choice is also made if the possible prospect of success of procedure a) is low. This may be the case, for example, if critical yarns are spun on the spinning station, which is problematic for finding the yarn ends on the cop. Another reason may also be that the equipment required for the process of searching for the end of the yarn on the cop does not or cannot not work completely. It is also advantageous in this case that instead of trying procedure a), procedure b) is selected immediately, at least until the desired faulty device for positioning the yarn ends is repaired. In order to facilitate the productivity of ring spinning machines, it is therefore acceptable to produce cop with yarn interruption in the joint region. The ring spinning machine can therefore be operated as efficiently as possible in this sense.

Therefore, the method according to the present invention has an advantage in that productivity of the ring spinning machine can be significantly improved since the piecing apparatus can alternatively select the procedure a) or the procedure b) as a preferable procedure for eliminating the piecing. This choice takes into account the procedure a) or b), with which the ring spinning machine is also able to produce the highest possible cop quality or the highest possible number of cops without interrupting the yarn at the highest possible production rate. On the one hand, if sufficient time is available, attempts are made to obtain a particularly high quality piecing device, as is possible with procedure a), since no piecing device is required at any other spinning station. Since this procedure a) is very time-consuming compared to procedure b), in order to facilitate the productivity of the ring spinning machine, it is attempted to keep the downtime of the individual spinning stations as short as possible, so that the piecing device attempts to bring the individual spinning stations back into production as quickly as possible at the expense of cop quality. In the case of a time-critical ring spinning machine, without the previous procedure a), the procedure b) for piecing a new yarn to the requested spinning station of the ring spinning machine is selected accordingly.

It is also advantageous to select program a) if the cop is produced without yarn interruption or if there have been a predetermined number of yarn interruptions on the cop. If possible, if a particularly high-quality cop is to be produced without yarn interruption, the procedure a) for piecing the yarn interruption is first attempted. The longer treatment time is not taken into account, but the quality of the cop is noted. It may also be advantageous if the required quality of the cop allows a predetermined number of yarn interruptions on the cop, but a number exceeding this predetermined number is no longer acceptable. In this case, the alternative method of the present invention is used as long as the predetermined number of yarns is allowed to break. Therefore, the first attempt always successfully uses program a).

Advantageously, the program b) is selected if the number of spinning stations waiting for the piecing device exceeds a predetermined number. If there is a yarn break at this predetermined number of spinning stations and therefore the respective spinning station cannot produce any further yarn, a faster program b) is selected until the predetermined number of spinning stations is again below the limit. Thereafter, the alternative procedure a) or b) according to the invention is used again.

It is also advantageous if the yarn spun at the spinning station exceeds a predetermined yarn count, the program b) is selected. Experience has shown that it is more difficult to find the yarn ends on the cop if the predetermined yarn count is exceeded, i.e. very thin yarns are present. Therefore, it takes longer to plan until the yarn end is usually found, or it may even be assumed that it is often not found at all. In this case, it is advantageous to select the safety procedure b) so that the piecing devices are not held too long at the individual spinning stations.

It is also advantageous if procedure b) is selected if the repair of a yarn break using procedure a) is unsuccessful. In order to obtain as high a quality cop as possible without yarn interruptions inside the cop, it is advantageous to try procedure a) first. Only if the procedure a) is unsuccessful, procedure b) is used.

Advantageously, the program b) is selected if the device for searching for the yarn does not work for the program a). Such a device for searching for a yarn can be, for example, a suction nozzle which searches for the yarn end on the surface of the cop. Such suction nozzles are also usually designed to be movable. For example, if the drive of the suction nozzle has failed, the piecing device remains operational, since it can continue to perform the piecing process using procedure b), and the productivity of the ring spinning machine is not reduced and the quality of the produced cop is only slightly reduced.

It is also advantageous if the selection of the programs a) or b) is carried out by the control of the spinning machine or by an operator. The control device can process the information from the state of all spinning stations of the ring spinning machine and select the most productive program a) or b) for the piecing devices. It may also be advantageous to manually set the preferred program a) or b) by an operator, in particular if the operator determines that certain means of the joint apparatus are not functioning.

Advantageously, in procedure a) the yarn end of the broken yarn is searched for on the cop or at a predetermined position of the spinning station. In the case of procedure a), the yarn end of the cop must be grasped. In order to be able to find the yarn end of the cop as quickly as possible, the surface of the cop is searched for the yarn end. Alternatively, a predetermined position can also be provided at the spinning station in order to find the yarn end as quickly as possible. For example, in the case of a purposeful interruption of the spinning process, the yarn end at the spinning station can be stopped before it reaches the cop and can be picked up again at this point by the piecing device.

It is also advantageous to draw the yarn end into the rotor and/or the yarn guide. The piecing device is preferably capable of threading the yarn ends from the drafting system or from an auxiliary yarn supply which carries the auxiliary yarn through the rotor and/or the yarn guide of the spinning station.

It is also advantageous to mark whether the cop has a splice according to procedure a) and/or b) and/or how much length of yarn between two yarn breaks is wound on the cop. Such marking may be accomplished, for example, by a data carrier attached to the cop. It is possible to record on the data carrier whether and how many splices according to program a) or program b) are contained on the cop. Information about the length of the thread wound on the cop between two thread interruptions can also be recorded on the data carrier. This is advantageous for further processing of the cop on a subsequent winder. The data carrier can be designed to be electronically or optically readable, for example with a label that can be read by an operator, but it is also possible to connect the data carrier to the cop. The marking can be done directly or indirectly on the cop. For example, the data carrier can be fastened on the cop itself or on a transport device for the cop on which the cop is arranged. Data can also be recorded directly or indirectly on a data carrier. On the one hand, therefore, the data carrier can directly have the corresponding information, i.e. itself. However, the cop can also indirectly have, for example, a fixed, constant marking, for example a number, and this number is linked in a database with corresponding information about the program a) or b) or the length of the individual yarn sections.

During the further processing of similar yarns and/or cop on subsequent preparation stations and/or winders, the selection of the programs a) or b) is advantageously made on the basis of empirical values. For example, during further processing, it may be determined that there may be a maximum certain number of yarn interruptions on the cop or in a batch (e.g., a maximum of 3 yarn interruptions or heterogeneous yarns for each cop, or a maximum of 120 yarn interruptions or heterogeneous yarns for each batch), otherwise the efficiency of the winder is significantly reduced. With this experience, the maximum number of allowable yarn interruptions, i.e. splices according to procedure b), on ring spinning machines may be limited in the case of similar yarns or cop. For example, the efficiency of the winder may be reduced because it takes too much time to prepare the yarn ends.

In an advantageous embodiment of the invention, the selection of a program a) or b) can also be determined if the successful implementation of the program a) and/or b) is stored in a data memory and the possible prospects for the success of the program a) are thus determined, in particular in relation to a particular batch. Procedure a) is used more often, and procedure b) is omitted more precisely, if there is a high potential prospect of success of procedure a) for the corresponding batches of yarn.

If, at the start of a batch, the possible prospects of success of the program a) of the batch are advantageously used as starting parameters and/or are updated while the batch is running and stored in an updated manner at the end of the batch, the experience already made for further spinning on the batch or the yarn can be used first. If in the course of further demonstration new findings and experiences with respect to the prospect of success of the procedure a) occur, the experience value is also updated and saved and can be used again as starting parameter for the next batch. This has the advantage that the possible limitations of the program a) can be applied at the start of a batch. Therefore, the efficiency of the ring spinning machine can be optimized. For example, dynamic optimization may be performed during production. If the preparation station/winder is capable of processing cop, the number of allowable heterogeneous yarns can be increased despite the relatively large number of heterogeneous yarns, and vice versa.

The piecing device according to the invention for forming piecings on a ring spinning machine has means a) and b) for automatic piecing in the event of yarn breakage in order to connect the yarn ends to the roving.

The device a) has search and processing means in order to search for the yarn ends of broken yarns, detect the found yarn ends and use them for piecing, in order to obtain a cop without yarn interruption. The device b) has a fastening and processing device for fastening an auxiliary yarn on the cop from a yarn supply, then separating the auxiliary yarn to obtain a yarn end fastened on the cop, and using the yarn end for splicing to obtain a cop with yarn interruption. The search and processing means and the fastening and processing means can be implemented in a single or different structural units. According to the invention, the piecing device comprises control means adapted to select whether device a) or device b) is used to provide the yarn ends, depending on the degree of capacity utilization of the piecing device and/or the possible prospect of success of device a). The splicing device can therefore operate as efficiently as possible, provided that device a) requires more time to splice than device b). The joint apparatus according to the invention therefore makes a significant contribution to the fact that: ring spinning machines are efficient and are not lowered by spinning stations which are left idle for a long time and have to wait for piecing devices. Alternatively, the piecing device uses either device a) or device b) to perform the piecing process, depending on whether the quality of the cop to be produced or the productivity of the spinning station is required.

The ring spinning machine is equipped with a plurality of spinning stations at which rovings come out from delivery rollers of a drafting system and are converted into yarns and wound on cops with a rotor and a rotating cop. If the piecing is connected according to the procedure a) or b) or using the device a) or b), the spinning process can be continued again. The control device can either operate automatically according to specified rules or be manually influenced and switched by an operator.

It is also advantageous if the device a) has at least one suction device. With the suction device, the device a) is able to suck the yarn ends on the surface of the cop and to further process them for the piecing process. The suction device can be designed to be movable, for example, wherein it can be moved towards the cop or away from the cop.

It is also advantageous if the device b) has an auxiliary bobbin for the yarn supply. The auxiliary yarn is stored on the auxiliary bobbin and used by device b) for the piecing process as required. The auxiliary yarn may be of the same type as the yarn itself. However, it may also be different from the yarn, for example to simplify the piecing process, or to better distinguish the auxiliary yarn from the ordinary yarn.

Furthermore, it is advantageous if the control device is adapted to evaluate information about the number of requests of the piecing devices for the spinning machine. Based on the joining process to be carried out by the joining device, it can be determined whether to use a slower device a) operating with a higher quality or a faster device b) operating with a poorer quality or differently, in order to obtain a desired and permitted ratio of productivity and quality.

It is also advantageous if the piecing device and/or the control device cooperate with a marking device for marking the cop in order to mark whether the cop has a piecing of device a) and/or device b). The marking device directly or indirectly marks the cop, for example by conveying a carrier through it. This information can be passed on to the machine controller in order to be able to convey the corresponding cop to a suitable further processing point.

A piecing robot for a ring spinning machine is known, which searches for a yarn end on a cop if possible, and thus performs a piecing process. If the yarn end cannot be found, spinning is carried out with the auxiliary yarn carried along. Since the splicing with the auxiliary yarn can generally be carried out faster, in the case of a normal splicing with the auxiliary yarn, a significantly greater number of yarn breaks can be performed per unit time and with a single splicing robot. In a simple embodiment, the operator can choose in which mode (mixed or only with auxiliary yarn) to operate the piecing robot. However, it is particularly advantageous that, due to the yarn breakage location (or the degree of capacity utilization of the piecing robot), the machine itself decides whether the search process for the thread end should be reinforced or omitted entirely, depending on the automatic efficiency optimization.

The device is designed according to the preceding description and the mentioned features can be present individually or in any combination. The piecing devices can be manufactured and sold with ring spinning machines. However, the piecing devices can also be manufactured and sold as separate structural units and attached to existing ring spinning machines.

Drawings

Aspects of the invention are explained in more detail using the embodiments shown in the following figures and the related description. In the drawings, schematically:

FIG. 1 is a side view of a ring spinning machine and a piecing device;

FIG. 2 shows a cop;

FIG. 3 is a side view of the winder; and

fig. 4 shows a diagrammatic representation of a top view of the spinning device.

Detailed Description

In the following description of the alternative embodiments shown in the drawings, the same reference numerals are used for the same and/or at least comparable features as compared to the above-described embodiments in terms of their design and/or mode of operation. Unless these are explained in detail again, the design and/or mode of operation of the features correspond to the design and mode of operation of the features already described above. For the sake of clarity, not all identical components are provided with reference numerals, but they are drawn in the same way.

Fig. 1 is a side view of a ring spinning machine 1 and a piecing device 2. The piecing devices 2 are 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 drafts the roving 6 with roller pairs running at different speeds and leaves the drafting system 5 on a transport roller 7. The drawn roving 6 then runs in a known manner through a thread guide 8 and a rotor 9 in order to finally be wound as a yarn 10 on a cop 11. The cop 11 is set in rotation by a drive 12, whereby the rotor 9 makes a turn around the cop 11 and thus causes a rotation in the yarn 10. Fig. 1 shows a spinning station 13, at which the yarn 10 is broken and must be pieced again onto the roving 6. According to this illustration, the yarn end 14, which is the yarn end 10 wound on the cop 11, is sucked into the search and processing device 15 of the piecing device 2. The yarn end 14 is searched by the search and processing device 15 on the surface of the cop 11 using suction, passes through the rotor 9 and the yarn guide 8 and is now ready to be pieced onto the roving 6. For this purpose, the search and processing device 15 can be pivoted according to the double arrow shown and can also be designed to be movable in other ways, for example more linearly. The search and processing device 15 or the piecing device 2 can have additional processing elements (not shown) in order to be able to grasp the yarn end 14 on the cop 11, to pass it through the rotor 9 and the yarn guide 8 and to piece it to the roving 6 in the drafting system 5.

The piecing device 2 also includes a fastening and handling device 35 with a yarn supply 16. A yarn supply 16 is provided in the robot 3 in the form of an auxiliary bobbin. The yarn supply 16 has an auxiliary yarn 17 which can be pulled off from the auxiliary bobbin by means of a conveyor roller 18. According to this embodiment, the conveyor roller 18 provides the yarn end 14' of the fastening and handling device 35. Which moves in the direction of the yarn end 14 'and causes the yarn end 14' to perform a piecing process. The conveyor roller 18 is set into a rotational movement by the control device 19 and removes the desired length of the auxiliary yarn 17 from the yarn supply 16. The control means 19 also ensure a corresponding movement of the search and processing means 15, the fastening and processing means 35 or other processing means (not shown) of the jointing apparatus 2, in order to be able to carry out the jointing process correctly.

In order to splice the yarn ends 14 'of the auxiliary yarns 17, the yarn ends 14' are placed on the cop 11 and there fastened to the cop 11, for example by several turns (see fig. 2). The auxiliary yarn 17 passes through the rotor 9 and the yarn guide 8, comes into contact with the roving 6 and separates before or after it, so that this end of the yarn, which is no longer visible afterwards, forms a joint with the roving 6 in the drafting system 5.

The control device 19 provides a signal to the piecing device 2 as to whether the yarn end 14 or the yarn end 14' is used in the piecing device. This decision is made according to the degree of capacity utilisation of the piecing device 2 and/or the prospect of possible success when using the yarn ends 14 for piecing. Since there is no yarn interruption on the cop 11 when directly spinning the yarn 10 of the cop 11 and its yarn end 14, the yarn end 14 is preferably used for splicing. However, in this case, it is disadvantageous that finding the yarn end 14 on the cop 11 is time-consuming and not always successful. If it is therefore necessary for the piecing device to spin at a plurality of further spinning stations 13, since there is also a yarn break there, it is advantageous according to the invention if the piecing device 2 selects a faster and safer piecing process using the auxiliary yarn 17. In this case, the yarn end 14' of the auxiliary yarn 17 is nipped and placed on the cop 11 at a predetermined point on the conveyor roller 18. The yarn end 14' forms an interruption in the yarn 10 located on the cop 11. Such interruption of the yarn 10 on the cop 11 leads to an interruption of the winding process during further processing on, for example, a winder and may lead to a reduction in the efficiency of the winder there. However, this procedure is more advantageous for the productivity of the ring spinning machine 1, since a better but more time-consuming piecing is carried out with the yarn ends 14, but in order not to unnecessarily reduce the productivity of the spinning machine 1, in the case of abnormal work loads or if it is foreseen that the yarn ends 14 can only be found very badly or indefinitely on the cop 11, the auxiliary yarn 17 with its yarn ends 14' is used.

A marking device 20 is provided to mark the cop 11 during further processing as a cop 11 with one or more yarn interruptions due to the use of the splice of the yarn end 14' or as a cop 11 without yarn interruptions. The marking device 20 marks the cop 11, for example by means of a corresponding marking or inscription on a data carrier 21 (see fig. 2). Thus, for example, if the cop 11 has a yarn interruption, it can be specially treated during further processing. Such a special treatment may mean that the subsequent machine (e.g. a winder) can work as productive as possible despite these yarn interruptions.

Fig. 2 shows the cop 11 connected to the staple tray 22. The staple tray 22 is a transport element with which the cop 11 can be transported in the spinning apparatus. To this end, the cop 11 is attached to the staple tray 22 via a sleeve 23 on which the yarn 10 is wound. The data carrier 21 is provided for marking whether or how many yarns are interrupted on the cop 11. The data carrier 21, which is shown here, for example, as a bar code, can be recognized at a corresponding recognition point on the spinning device and evaluated with regard to the further processing of the cop 11. The data carrier 21 can be fastened to the sleeve 23, for example. However, it may also be provided on the staple tray 22. In addition to the information about the presence of a yarn interruption, the data carrier 21 can also provide information about the length of at least one yarn portion wound on the cop. In fig. 2, also the yarn end 14 ″ can be seen, which is located on the surface of the cop 11. The yarn end 14 ″ forms the end of the complete yarn 10 wound on the cop 11. On the other hand, the broken line indicates that there is a yarn break on the cop 11. Thus, the yarn end 14 resulting from the start of winding the cop 11 with the yarn 10 due to yarn breakage is shown. By piecing the auxiliary yarn 17 (see fig. 1), a further yarn end 14' is formed on the cop 11, which is also indicated by a dashed line since it is not visible. This yarn end 14' is now located inside the cop 11, since the further yarn 10 is wound on the cop 11 after splicing with the auxiliary yarn 17. In some cases, this yarn end 14' may also be visible, for example, if it is fixed in a defined position on the sleeve 23. Typically, the yarn ends 14' and yarn interruptions are not visible in the cop 11. It is therefore advantageous to note on the data carrier 21 whether the yarn interruption (i.e. the yarn ends 14 and 14') is located inside the cop 11 or how many yarn interruptions are present.

Fig. 3 shows a schematic of a side view of the winder 25. From the cop 11a provided on the staple tray 22, the yarn 10 is wound on the cross-wound bobbin 26. On the winding machine 25, a suction tube 27 which can be pivoted according to the double arrow and a gripper 28 which can also be pivoted and optionally moved linearly are provided. Only one of the winding stations 29 of the winder 25 is shown. With the suction tube 27, after the yarn breaks, the end of the yarn that has been wound on the cross-wound bobbin 26 can be searched for and detected. The sketched gripper 28 is also able to search the yarn end 14 from the cop 11a and to grasp it after the yarn breaks. The two yarn ends can then be introduced into the splicing device 30 and connected to one another in a known manner. Yarn breakage may occur during the normal winding process. Yarn breakage can also occur if there is a yarn interruption at both ends 14 and 14' of the yarn on the cop 11 a. As described above, the two yarn ends 14 and 14' are formed when the auxiliary yarn 17 is pieced to the upstream ring spinning machine 1. This yarn interruption is wrapped with the yarn 10 during the subsequent further spinning of the yarn 10 on the ring spinning machine 1. However, during the unwinding of the yarn 10 on the winder 25, this interruption of the yarn inevitably leads to an interruption of the winding process. In the event of such yarn interruption, the yarn end 14' is wound onto the cross-wound bobbin 26, while the yarn end 14 remains on the cop 11 a. However, the position of the yarn end 14 on the cop 11a is uncertain. Thus, the cop 11a is removed from the spinning station 29 and replaced by a cop 11 b. In the cop 11b, the yarn end 14 ″ located outside the cop 11b has been brought to a defined position in the preparation station and can therefore be quickly picked up by the gripper 28.

Fig. 3 shows different variants of the cop 11a to 11 d. When the cop 11a is currently unwinding with the two yarn ends 14 and 14' still inside, the following cop 11b has the yarn end 14 ″ located in a defined position on its periphery. Two yarn interruptions can be found inside the cop 11 b. Thus, two yarn ends 14 and two yarn ends 14' are present inside the cop 11 b. In contrast, the cop 11c has no interruption of the yarn anyway. If no yarn breakage occurs during the rewinding process, the yarn 10 will be able to be completely wound onto the cross-winding bobbin 26 through the cop 11 c. Finally, in the cop 11d, there is again a yarn interruption with a yarn end 14 and a yarn end 14'.

Fig. 4 shows a diagrammatic representation of a top view of the spinning device 40. According to the present embodiment, a ring spinning machine 1 is shown in a spinning apparatus 40. Of course, a plurality of ring spinning machines 1 may be present in the spinning apparatus 40. The ring spinning machine 1 has a plurality of spinning stations 13. The robot 3 with its piecing device 2 (see fig. 1) is traversed along the ring spinning machine 1 and, if necessary, performs a piecing process at the respective cop spinning station 13. The finished cop 11 produced at the spinning station 13 is then transferred to a transport device 41 which transports the cop 11 (optionally on a staple tray 22) to a preparation station 42. In the preparation station 42, the exposed yarn end is searched for and placed by the yarn search device 43 at a defined point on the cop 11. The cop 11 is then transported on the transport device 41 to one of the winders 25. When rewinding the cop 11 onto the cross-wound bobbin 26 at the winding station 29, the cop 11 is removed from the winding station 29 and sent back to the preparation station 42 once a yarn break occurs. The now exposed yarn end 14 ″ of the yarn break can be searched again and placed again at a defined point on the cop 11. The cop 11, now only partially wound, is fed again to the winding station 29 of one of the winders 25.

The cop 11 delivered on the delivery device 41 is marked in order to record the number of known yarn interruptions caused by the piecing process of the auxiliary yarn 17 on the ring spinning machine 1. This mark of the cop 11 is read by the recognition device 44 and is transferred to the device controller 45. The apparatus controller 45 is connected to all the basic devices of the spinning apparatus 40. The marking of the cop 11 can be, for example, in the form of an optically readable code, for example a bar code or a pixel code, or in the form of a data carrier connected to the cop 11, which data carrier has been marked electronically accordingly and can be read. The marking of the cop can also be carried out in such a way that the auxiliary yarn 17 used for splicing inside the cop 11 is different from the normal yarn 10 used for the remaining windings. It is also possible to link the constant marking of the cop 11, for example the number of the cop 11, to data in a database, for example in the machine controller 45, in which database or machine controller information about the cop 11 is stored.

The transport control 46 is instructed via the machine control 45 that the respectively identified cop 11 is fed via the transport path 47 to the specific winder 25 or to the specific winding station 29. The cop 11, containing one or even more known yarn interruptions, is preferably fed to a winder 25 or winding station 29, which is located near the preparation station 42. Since it is safe to assume that for this type of cop 11 with known yarn interruption they must be fed again to the preparation station 42, this control of the cop 11 means that the return transport path from the winding station 29 to the preparation station 42 can be kept as short as possible. These short transport paths for the cop 11 allow a faster re-feeding of the ready cop 11 to the winding station 29, which is expected to have to be transported to the preparation station 42 more frequently. In contrast, at least the cop 11, for which no yarn interruption is known, is conveyed to the winding station 29 by the winder 25 or the winder 25 which is further away from the preparation station 42, since in the case of these cops 11 it is assumed that they do not have to be (at least not positively) returned to the preparation station 42. In summary, the treatment process is thus shortened and accelerated, as a result of which all the cop 11 present can be treated more quickly.

Depending on the degree of capacity utilization of the winding machine 25 or the winding station 29, the cop 11 with at least one additional, known yarn interruption can be fed to the parking position 48 or processed mainly before the other cops 11. When the winder 29 is started up after a change process on the ring spinning machine 1, all winding stations 29 of the winder 25 must be supplied with the cop 11 as quickly as possible. There, cop 11 which has to be replaced again after a short operating time is to be avoided, since they have additional known yarn interruptions, thus additionally burdening the preparation station 42. A cop 11 of this type is therefore preferably fed to the parking position 48 so as not to interfere with the other cops 11. When all winding stations 29 are in operation and there is sufficient ready cop 11 in the system, one can preferably handle cop 11 with additional known yarn interruptions. Therefore, such a cop 11 is preferentially treated or omitted depending on the stage or capacity utilization of the winder 25.

Even if there are a plurality of preparation stations 42 in the spinning device 40, the device controller 45 is able to determine to which preparation station 42 the cop 11 is preferably conveyed after recognizing the number of yarn interruptions in the cop 11. For example, it can be provided that certain preparation stations 42 are specially dedicated to searching for the yarn ends 14', which are originally located inside the cop 11 and are therefore more difficult to find than the yarn ends 14 ″ located on the outer circumference of the finished cop 11 after leaving the ring spinning machine 1. For example, such a special treatment may include a stronger or longer suction of the cop 11, so that this more difficult yarn end 14 "can be found more easily. The preparation station 42 dedicated to this way does not block the cop 11, whose end 14 "can be found more quickly and easily. Thus, the cop 11 with known yarn interruption can be fed to a predetermined preparation station 42 and/or to a predetermined winder 25 or winding station 29.

The invention is not limited to the embodiments shown and described. Modifications are possible within the scope of the claims, such as combinations of features, even if these are shown and described in different embodiments.

List of reference numerals

1 Ring spinning machine

2 splice device

3 robot

4 rollers

5 drafting system

6 Rove

7 conveying roller

8 thread guide

9 rotor

10 yarn

11 cop

12 driver

13 spinning station

14 ends of yarn

15 search and processing device

16 yarn supply source

17 auxiliary yarn

18 conveyor roller

19 control device

20 marking device

21 data carrier

22 nail tray

23 casing tube

25 winding machine

26 cross winding bobbin

27 suction pipe

28 holder

29 winding station

30 splicing device

35 fastening and handling device

40 spinning equipment

41 conveying device

42 preparation station

43 yarn searching device

44 identification device

45 equipment controller

46 transfer controller

47 conveying path

48 parking position.

Claims (19)

1. A piecing method for a piecing device (2) of a ring spinning machine (1) having a plurality of spinning stations (13) at which rovings (6) emerge from delivery rollers (7) of a drafting system (5) and are converted into a yarn (10) and wound onto a cop (11) with a rotor (9) and a rotating cop (11),

wherein, in the event of a yarn break, the piecing device (2) automatically produces a piecing in which the yarn ends (14, 14') are connected to the roving (6) emerging from the delivery roller (7) and the spinning process is then continued, and

wherein alternatively, according to

-procedure a) of searching for the yarn end (14) of the broken yarn (10), the found yarn end (14) being detected and used for splicing in order to obtain a cop (11) without interruption of the yarn; or

-according to procedure b), an auxiliary yarn (17) from a yarn supply (16) is fastened to the cop (11), then the auxiliary yarn (17) is separated in order to obtain a yarn end (14') fastened to the cop (11), and the yarn end (14') is used for splicing in order to obtain a cop (11) with yarn interruption,

it is characterized in that the preparation method is characterized in that,

depending on the degree of capacity utilization of the piecing device (2) and/or depending on the possible prospects of success of procedure a), it is selected whether the yarn ends (14, 14') are provided according to procedure a) or according to procedure b), provided that procedure a) takes more time than procedure b).

2. Jointing method according to the preceding claim, characterized in that procedure a) is selected if the cop (11) is to be produced without yarn interruption or if there have been a predetermined number of yarn interruptions on the cop (11).

3. Joining method according to any of the preceding claims, characterized in that a program b) is selected if the number of spinning stations (13) waiting for the joining device (2) exceeds a predetermined number.

4. Piecing method according to one of the preceding claims, characterized in that a program b) is selected if the yarn (10) spun on the spinning station (13) exceeds a predetermined yarn count.

5. Joining method according to any of the preceding claims, characterized in that procedure b) is selected if the repair of the yarn break using procedure a) is unsuccessful.

6. Piecing method according to one of the preceding claims, characterized in that a program b) is selected if the device for searching for the thread (10) does not function for the program a).

7. Piecing method according to any one of the preceding claims, characterized in that the selection of a program a) or b) is carried out by a control device of the spinning machine or by a machine controller (45) or by an operator.

8. Piecing method according to one of the preceding claims, characterized in that in procedure a) the yarn end (14) of the broken yarn (10) is searched for on the cop (11) or at a predetermined position of the spinning station (13).

9. The piecing method according to any one of the preceding claims, characterized in that the yarn ends (14, 14') are drafted into the rotor (9) and/or yarn guide (8).

10. Piecing method according to one of the preceding claims, characterized in that the cop (11) is marked to determine whether it has a piecing according to procedure a) and/or b) and/or the length of the yarn (10) wound on the cop (11) between two yarn interruptions.

11. Piecing method according to one of the preceding claims, characterized in that the selection of a program a) or b) is carried out on the basis of empirical values during further processing of similar yarns (10) and/or cops (11) on a subsequent preparation station (42) and/or winder (25).

12. The joining method according to any one of the preceding claims, characterized in that the successful implementation of the programs a) and/or b) is stored in a data memory and from this the possible prospects of the success of the program a) are determined, in particular with respect to a specific batch.

13. The joining method according to any one of the preceding claims, characterized in that the possible prospects of success of a program a) of a batch are used as starting parameters at the start of the batch and/or are updated while the batch is running, and are stored in an updated manner at the end of the batch.

14. A piecing arrangement for producing piecings of a ring spinning machine (1),

wherein, in the event of yarn breakage, the piecing device (2) has means a) and b) for connecting the yarn ends (14, 14') to the roving (6) for automatic piecing, and

wherein the device a) has a search and processing device (15) for searching for the yarn ends (14, 14') of the broken yarn (10), detecting the found yarn ends (14, 14') and using them for piecing, in order to obtain a cop (11) without yarn interruption, and

said device b) having a fastening and processing device (35) for fastening an auxiliary yarn (17) from a yarn supply (16) on the cop (11), then separating the auxiliary yarn (17) in order to obtain a yarn end (14, 14') fastened to the cop (11), and using the yarn end (14') for splicing in order to obtain a cop (11) with yarn interruption,

it is characterized in that

The piecing device (2) comprises control means (19, 45) adapted to select whether the device a) or b) is used for providing the yarn end (14, 14') depending on the degree of capacity utilization of the piecing device (2) and/or the possible prospect of success of the device a).

15. Piecing device according to the preceding claim, characterized in that the piecing device (2) cooperates with an evaluation device adapted to evaluate the time and/or the possible prospect of success of the means a) and/or b) for piecing the yarn (10).

16. Jointing device according to any one of claims 14-15, characterized in that said means a) have suction means.

17. Piecing device according to one of claims 14 to 16, characterized in that the device b) has an auxiliary bobbin for the yarn supply (16).

18. Piecing device according to any of the claims 14 to 17, characterized in that the control means (19, 45) are adapted to evaluate information about the number of requests of 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) cooperate with a marking device (20) in order to mark whether the cop (11) has a piecing of the device a) and/or the device b).

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