CH714064A2 - Device for cleaning yarn defects from a yarn. - Google Patents

Abstract

The invention relates to a device 18 for cleaning yarn faults categorized into different types of yarn defects from a yarn 4, wherein the device 18 has a measuring head for measuring at least one predefinable yarn parameter and is adapted, in the event of deviation from a value range assigned to the yarn parameter, the presence of a yarn fault and of To signal yarn type and based on the Garnfehlersignal to cause a cleaner cut, by means of which the yarn error runs onto a package 3 producing a package forming textile machine. According to the invention, the device 18 is assigned a memory unit 8 in which a thread search program for a yarn end search of a top thread designed suction nozzle 14 of the textile machine is stored retrievable stored, and the device 18 is adapted, depending on the signalized Garnfehlertyps the associated thread search program for detecting of the accumulated on the package 3 yarn end of the upper thread by means of the suction nozzle 14 to initiate.

Description

Description: The invention relates to a device for cleaning yarn defects categorized into different types of yarn defects from a yarn, a textile machine producing bobbins with such a device, a memory unit for the callable storage of at least one thread search program assigned to a yarn defect type, and a method for detecting a bobbin accrued thread end.

In the textile industry, various types of winding machines producing textile machines have long been widespread. In addition to open-end rotor spinning machines, large numbers of dishwashers are used, for example.

At the workplaces of dishwashers, spinning bobbins, which were produced on ring spinning machines and contain only relatively little yarn material, are rewound to form large-volume winding packages. The yarn is monitored for thread defects during the rewinding process, thread defects being cut out and replaced by splices that are almost identical in thread.

For this purpose, both an upper thread retrieved from the package and a lower thread coming from the package are always required at the winding stations of a dishwasher.

Usually, in the case of a controlled cleaner cut via the winding unit computer of the winding unit concerned, an automatic thread connection automatic at the work station is activated.

That is, first a suction nozzle on the surface of the slowly rotating winding coil against the winding direction is acted upon by suction air. After the upper thread end has been gripped, the suction nozzle swivels into a thread insertion position in which the suction nozzle opening is positioned below a thread connecting device. Then a looper tube positioned in a lower starting position swivels into an upper working position and brings along a bobbin thread pulled off the payout spool.

The numerous jobs each have a job computer, which in turn is connected to a central control unit of the textile machine.

In general, the responsiveness of the thread cleaner is adjustable on the central control unit of the textile machine, that is, it can be specified centrally whether an irregularity is classified as a thread defect. Thread defects are understood to be thread defects which occur frequently and rarely, the thread defects which frequently occur also being referred to as imperfections and, in addition to thick and thin spots, also comprising nits / nubs. If irregularities are recognized and classified as thread defects because specified tolerance limits have been exceeded, the thread cleaner triggers a cleaner cut.

[0009] DE 19 640 184 A1, for example, discloses that a thread is drawn off a pay-off spool, for example a spinning cop, and wound onto a package, for example a package, by means of a winding device. The running thread is passed through the measuring head of a yarn cleaner and through a cutting device. The yarn cleaner records a measurement variable that represents the quality of the thread. If the yarn cleaner detects an intolerable error, that is, if the measurement variable deviates from specified values, a so-called cleaner cut is triggered by the yarn cleaner, that is to say the cutting device is activated in order to remove the defective part of the thread. After cutting the thread, the thread end with the defective part runs onto the package. The end of the thread is gripped by a swiveling suction nozzle and the defective piece of thread is suctioned off. The upper thread coming from the package is placed in a thread connecting device and the defective piece of thread is cut off. Correspondingly, the lower thread coming from the payout spool is inserted into the thread connecting device by means of a swiveling hook tube and a thread connection is established.

[0010] EP 0 531 894 A1 discloses a method and a device for classifying and cleaning yarns, with which yarn defects are mapped two-dimensionally over a predefinable yarn length due to a deviation from the nominal value of the yarn thickness. The yarn defects are detected by means of a measuring device with regard to the diameter and their length, then evaluated and classified in classification fields of an error matrix. For this purpose, the frequency of the occurrence of yarn defects that meet the respective classification criteria is recorded numerically in the classification fields and displayed in two dimensions. By means of the display on the screen, the occurrence of the frequency of errors can be read from the displayed numbers in each classification field.

The known methods and devices, however, have in common that although different types of yarn defects are recognized and detected, a thread search program for the suction nozzle for detecting the upper thread is present and is being carried out. It is also known in connection with the upper thread detection to optimize the distance of the suction nozzle to the package and to continuously adjust it over the entire bobbin travel and to increase the negative pressure due to the detection of the upper thread if the upper thread detection is unsuccessful, but the thread search program becomes uniform for all detected yarn defects executed.

A first aspect of the invention therefore relates to a device for cleaning yarn defects categorized into different types of yarn defects from a yarn, the device having a measuring head for measuring at least one predefinable yarn parameter and being adapted if there is a deviation from a value range assigned to the yarn parameter a yarn error and the yarn error type and based on

CH 714 064 A2 to cause the yarn error signal to have a cleaner cut, by means of which the yarn error runs onto a package of a textile machine producing package packages.

The proposed device is characterized in that it is assigned a storage unit in which a thread search program for a suction nozzle of the textile machine designed for thread end search of an upper thread is stored for different yarn error types, and the device is adapted as a function of the signaled To initiate the thread search program for detecting the thread end of the upper thread that has run onto the package by means of the suction nozzle.

In this way, an individually adapted thread search program can be carried out for a thread defect type. Experiments have shown that different thread search parameters improve the detection of the upper thread for different types of yarn defects. Basically, yarn error types are divided into thick spots, thin spots and nits, although it is also possible within the scope of the invention to divide the individual yarn error types into further subcategories.

The thread search parameters include, for example, the level of the negative pressure, the distance of the suction nozzle to the peripheral surface of the package around the thread end of the upper thread coming from the package and to detect if and in what time interval the suction nozzle performs a pitching movement during the upper thread detection. Likewise, the suction nozzle can be continuously pressurized or pulsating. Basically, the thread search parameters include all parameters that are relevant for the detection of the upper thread.

It has emerged, for example, that it is advantageous in the case of thin spots if the suction nozzle is positioned closer to the circumferential surface of the package when the vacuum is higher. Thick areas, on the other hand, can already be reliably detected with a lower negative pressure and a suction nozzle which is further apart, and nits with a further reduced negative pressure which may be supported by a pitching movement of the suction nozzle.

The thread search programs are stored and accessible in a memory unit, so that the thread search program corresponding to the respective thread defect type can be carried out depending on the type of thread defect detected. This means that if the device detects a thick spot, for example, a so-called cleaner cut is initiated in order to clear this yarn error from the yarn and this type of yarn error is signaled. Since an individual thread search program is also stored in a storage unit which is assigned to the device for the thread defect type thick spot, this is selected and carried out by means of the suction nozzle for detecting the thread end of the upper thread which has run onto the package. This thread search program optimized for a thick point differs in at least one parameter from the other stored thread search programs for other types of yarn defects.

Through the individually adapted thread search programs for the different types of yarn defects, the detection rate of the thread search is improved, as a result of which the upper thread can be detected more quickly overall. As a result, the winding process can be continued more quickly after a cleaner cut and the efficiency of the textile machine is increased. An optimally set negative pressure, in which the suction nozzle is only subjected to the negative pressure that is required to detect the current thread end, ultimately also has a positive effect on the energy consumption of the textile machine.

In a preferred embodiment of the invention, a detection rate of the thread search for each type of yarn defect can be determined and stored, and if the detection rate deviates from a limit value, the thread search program is automatically adaptable.

If it is recognized and stored for each type of yarn error how often the thread end of the upper thread could not be detected by the suction nozzle and a limit value is specified in the storage unit which defines a number of permissible unsuccessful thread take-up attempts, the limit value is exceeded if the limit value is exceeded changed at least one thread search parameter. For example, the positioning of the suction nozzle on the package can be closer or further apart, or the negative pressure present in the suction nozzle is reduced or increased. Instead of a permanent negative pressure, the suction nozzle can also be pulsed with negative pressure or perform a pitching movement. Within the scope of the invention, individual or multiple thread search parameters can be changed in combination with one another.

Advantageously, the automatic adjustment of the thread search programs takes place individually for the corresponding job, for a production group or for the entire textile machine.

The automatic adaptation of a thread search program, in which at least one thread search parameter is changed due to the deviation from the limit value for the detection rate of the upper thread, can be selected such that this takes place, for example, for a specific job. This can be advantageous if, for example, a sample bobbin is wound on one of the workstations of the textile machine. However, it can also be advantageous to limit the automatic adjustment to one production group or one batch if several batches are manufactured on the textile machine at the same time or if not all jobs are occupied. It is also conceivable that the automatic adjustment of the thread search programs is carried out for the entire textile machine.

[0023] The storage unit is preferably formed by a job control device, a central control unit or an external storage unit.

CH 714 064 A2 Within the scope of the invention it is possible that the storage unit in which the various thread search programs are stored and can be called up is part of the already existing job control device or the central control unit. This is advantageous since existing facilities and structures can be used anyway without having to integrate complex new components. However, the storage unit could also be an external medium, such as a USB stick or an electronic device such as a computer, tablet, smartphone, smart watch or the like, which can be connected to the textile machine or the device. This can be, for example, a medium that can be docked to the device or the textile machine via a suitable interface, or can interact with them wirelessly.

[0025] A second aspect of the present invention relates to a textile machine producing winding packages, comprising a device for cleaning yarn defects categorized into different types of yarn defects from a yarn.

The textile machine producing winding packages is characterized in that at least one device is designed according to one of the embodiments described above.

With a textile machine of this type, winding processes which are interrupted on account of detected yarn defects and associated cleaning cuts can be continued again more quickly and thus more efficiently. The detection of the upper thread is improved by thread search programs individually adapted to different types of thread defects. The fact that fewer attempts are necessary to successfully pick up the thread end from the take-up spool can increase the overall effectiveness of the textile machine. The total number of attempts to grasp the upper thread and a level of vacuum adapted to the respective yarn defect type also reduces the vacuum consumption and ultimately optimizes the overall energy requirement of the textile machine.

A third aspect of the present invention relates to a method for detecting a thread end of an upper thread of an upper thread of a work station of a textile machine manufacturing a package on a package by means of a suction nozzle of the textile machine assigned to the package, the method comprising a first step of the controlled cleaning cut after signaling a yarn error and associated yarn defect type.

The method is characterized in that, in a second step, a thread search program assigned to the signaled yarn error type is called up from a storage unit, and in a third step the thread end of the upper thread that has accumulated is detected by means of the suction nozzle in accordance with the thread end search program that has been called up.

If there are individual thread search programs for different types of yarn defects, such as thick spots, thin spots or nits, and if the yarn error type is signaled when a yarn error is detected, then the upper thread is detected by the take-up bobbin using a thread search program specifically designed for this type of yarn error corresponding thread search parameters. Such thread search parameters include, for example, the distance of the suction nozzle to the package or whether the suction nozzle is positioned statically or dynamically, for example in pitching movements, in front of the package. Likewise, the level of the negative pressure with which the suction nozzle is acted upon to detect the end of the thread or whether permanent or pulsating negative pressure is applied to the thread search parameters of the thread search program.

The procedure according to the invention ensures that the upper thread can always be reliably and quickly detected by the suction nozzle after a cleaner cut, so that the interrupted winding process can be continued as quickly as possible.

In an advantageous embodiment, a detection rate of the thread end of the upper thread is determined and stored for each type of thread error, and the thread search program is automatically adapted when the detection rate differs from a limit value.

This development of the invention enables a further optimization of the upper thread search, because for each yarn defect type is separately recorded and stored, how often the upper thread could not be successfully taken up by the suction nozzle and previously defined a limit value for it, so if this limit value is exceeded the corresponding thread search program will be readjusted automatically. That means, for example, if a thick spot is detected and the suction nozzle is activated in accordance with the associated thread search program, and the upper thread is not detected by the suction nozzle, this is recognized and stored. If, for example, an unsuccessful thread search for a thick point is registered for the tenth time and the limit value ten was previously defined, the thread search program for thick points is adjusted after the tenth unsuccessful thread pick-up attempt by changing at least one thread search parameter. This can affect, for example, the level of the negative pressure present or the distance between the suction nozzle and the package. It is within the meaning of the invention to define such a detection rate, for example, per cleaner cut, per yarn defect type or lot-related.

In particular, the automatic adjustment of the thread search programs takes place individually for the corresponding work station, for a production group or for the entire textile machine.

The automatic adaptation of the thread search programs described above can be selected and carried out as required so that it takes place either per work station, for a production group, such as a batch, or for the entire textile machine.

CH 714 064 A2 [0036] The storage preferably takes place in the work place control device, in the central control unit or in an external storage unit.

Depending on the production structure, the thread search programs can be stored at different locations. This can be, for example, the job control device that is present at each individual job or the central control unit, which in turn is connected to the individual jobs. However, an external storage unit is also conceivable, which can be brought into physical or wireless contact with the device itself or the textile machine.

A fourth aspect of the present invention relates to a memory unit for retrievably storing at least one thread search program associated with a thread defect type for detecting a thread end of an upper thread that has run onto a winding spool of a winding spool by means of a suction nozzle of the textile machine.

The storage unit is characterized in that a thread search program for performing the method according to one of the above-described embodiments is available.

[0040] The storage unit can be designed as part of an already existing component, such as the workstation control device or the central control unit. However, the storage unit can also be designed externally, for example as a USB stick, as a computer or the like, which can be connected to the device or the textile machine via an interface or wirelessly. It is essential to the invention that the storage unit is designed in such a way that at least one thread search program for a specific type of thread defect can be stored and called up on it.

Further features and advantages of the invention will become apparent from the following description of preferred exemplary embodiments of the invention, with reference to the figures and drawings which show details essential to the invention, and from the patent claims. The individual features can be implemented individually or in any combination in any preferred embodiment of the invention.

Preferred exemplary embodiments of the invention are explained in more detail below with reference to the accompanying drawings.

1 shows a side view of a winding unit of a dishwasher;

Fig. 2 is a flowchart of the method.

In Fig. 1, a work station 1 of an automatic dishwasher is shown schematically in side view. Such dishwashers usually have a large number of similar work stations 1, also called reel stations, between their end frames (not shown).

As is known and therefore not explained in more detail, the spinning reels 2 produced on a ring spinning machine are rewound to form large-volume cross-wound bobbins on these winding units. The spinning heads 2 are the payout spools from which the yarn 4 is unwound. The cross-wound bobbins form the package 3 on which the yarn 4 is wound.

After their completion, the cross-wound bobbins are transferred to a machine-long cross-wound bobbin transport device 5 by means of an automatically operating service unit, preferably a cross-wound bobbin changer (not shown) and transported to a bobbin loading station or the like arranged at the machine end.

Such dishwashers also have a logistics facility in the form of a bobbin and tube transport system 6. In this bobbin and tube transport system 6, spinning heads 2 and empty tubes circulate on transport plates 7.

Furthermore, such an automatic dishwasher usually has a (not shown) central control unit which is connected via a machine bus both to the separate winding station computers of the individual winding stations and to a control device of the service unit. In this exemplary embodiment, the storage unit 8 is formed by the winding station computer.

Of the above-mentioned tube transport system 6, only the cop feed line 9, the reversibly drivable memory line 10, one of the transverse transport lines 11 leading to the winding stations and the tube return line 12 are shown in FIG. 1.

The delivered spinning reels 2 are rewound into large-volume cross-wound bobbins in the unwinding position 13, which is located in the region of the transverse transport paths 11 at the winding stations. As is known and therefore only hinted at, the individual winding units have various facilities which ensure that these workplaces operate properly. These devices are, for example, a suction nozzle 14, a gripper tube 15 and a thread connecting device 16.

The thread connecting device 16 is preferably designed as a pneumatic splicer. The pneumatic splicer is set back somewhat with respect to the regular thread run and has an upper clamping and cutting device and a lower clamping and cutting device.

CH 714 064 A2 Such bobbins also have thread tensioners 17, a device 18 according to the invention, which in this example is designed as a thread cleaner, and further devices, not shown in detail, such as a waxing device, a thread cutting device, a thread tension sensor and a bobbin thread sensor.

A winding device identified overall by the reference number 19 consists of a coil frame 20 which is mounted so as to be movable about a pivot axis 21 and has a device for rotatably holding a cross-wound bobbin.

During the winding process, the cheese lies with its surface on a grooved drum 22 and is driven by this via friction.

As already indicated above, each winding unit has a suction nozzle 14 and a gripper tube 15, which are each connected to a machine-long suction channel 23 via a suction air connection.

The suction nozzle 14 is pivotally mounted about an axis 24. The swiveling movement of the suction nozzle 14 is carried out by the swivel drive 25, which is arranged in the reel housing 26. The swivel drive 25 is controlled by the winding station computer. The suction nozzle 14 has a controllable connection (not shown) to the suction channel 23 in the region of the axis 24. The suction nozzle 14 has a suction slot 27 for sucking in or grasping a thread end that runs onto the cross-wound bobbin. The suction nozzle 14 can be positioned by means of the swivel drive 25 with its suction slot 27 in the region of the cheese. The suction slot 27 extends approximately parallel to the peripheral surface of the cheese. Deviations from parallelism result from the coil shape, for example in the case of conical coils.

The gripper tube 15 is pivotally mounted about an axis of rotation 28 and also has at its free end a gripper tube flap 29 which makes it possible to close the mouth of the gripper tube.

1 shows the state of the winding unit in the normal winding process. The suction nozzle 14 is positioned with its suction slot 27 in the region of the cheese and the suction slot 27 points in the direction of the cheese. The diameter of the cheese increases during the winding process. This changes the distance of the suction slot 27 from the peripheral surface of the cheese. To compensate for this, the suction nozzle 14 is moved about the axis 24 depending on the diameter of the cheese. In this way, the distance between the suction slot 27 and the peripheral surface of the cheese can be kept in a predetermined range.

The gripper tube 15 is positioned in a lower position during the normal winding process. This means that the hook tube mouth is positioned below the thread connecting device 16 and, from the operator's point of view, before the yarn 4 runs.

The processes in a cleaner cut are controlled in the present embodiment by the winding unit computer. However, it is also possible for the control to be carried out by another control device of the textile machine, for example the central control unit or by an externally connected control unit.

After a detected yarn defect, a cleaner cut is initiated. The lower thread 30 is usually held in the thread tensioner 17, while the upper thread runs onto the surface of the package. The yarn error type, in this example a thin spot, is also signaled.

As soon as the thread interruption is recognized by the winding unit, the suction nozzle 14 is acted upon by suction air, the level of the negative pressure being predetermined by the selected thread search program. At the same time the braking process of the cheese is initiated and the braked cheese is slowly rotated against the winding direction. Depending on the thread search program, the suction slot 27 of the suction nozzle 14 is positioned differently close to the peripheral surface of the cheese. The thread search program also specifies whether the suction nozzle 14 remains in this position continuously during the detection of the thread end or whether the suction nozzle 14 for example performs a pitching movement in the meantime.

If the upper thread could not or could not be detected properly by the suction nozzle 14, this is recorded and stored separately for the respective yarn defect type. A limit value is defined in the winding station computer, in this example there are ten unsuccessful attempts at thread detection for a thin point. As soon as the eleventh unsuccessful attempt to detect the upper thread is recognized, the thread search program stored in the winding station computer is automatically adapted. This means that the distance between the suction nozzle 14 and the cheese is reduced. The next time the thread is picked up after a thin spot has been recognized, this corrected distance between the suction nozzle 14 and the cheese is approached.

After the suction nozzle 14 has picked up the upper thread, it pivots from its starting position, which is shown in FIG. 1, in the direction of an end position, along the dashed line 31.

Already while the upper thread is being gripped and transported in the direction of the splicing device, the lower thread 30 is picked up by means of the hook tube 15. For this purpose, the gripper tube 15 is pivoted with its gripper tube mouth into an area just below the thread tensioner 17 and there pneumatically grips the lower thread 30. A control cam arranged on the gripper tube flap 29 slides over a lower control link (not shown), so that the gripper tube flap 29 opens. As soon as the looper tube 15 has gripped the lower thread 30, it can be swiveled up a little so that the looper tube flap 29 closes and the lower thread 30 is mechanically fixed. The gripper tube 15 is pivoted upwards in front of the splicing device along the broken line 32.

CH 714 064 A2 As soon as the looper tube 15 with the picked up lower thread 30 is positioned in front of the splicing device, the suction nozzle 14 with the picked up upper thread can be pivoted into a position in the area of the splicing device in front of the looper tube 15.

Then both the suction nozzle 14 and the hook tube 15 are pivoted further into their respective end positions 33, 34 and the upper and lower threads are inserted into the splicing device. The upper thread is also inserted into a thread cleaner, a cutting device and an open clamping and cutting device arranged below the splicing device. The lower thread 30 is inserted externally into the splicing device in an open clamping and cutting device arranged above the splicing device.

Both the upper thread and the lower thread are now inserted in the splicing device and the actual thread connection can be carried out. As soon as the thread connection is carried out, the hook tube 15 swivels back into the lower position, in which the hook tube mouth is in front of the thread path.

The suction nozzle 14 pivots back into its starting position and gradually releases the thread loop with the run-up of the bobbin drive, so that it is wound up at a relatively low speed. The suction slot 27 is then positioned again in the region of the cheese. Similarly, the gripper tube 15 swings back in a controlled manner.

The method 100 shown in FIG. 2 relates to the detection of a thread end of an upper thread that has run onto the take-up spool 3 by means of a suction nozzle 14. In a first step 110, a yarn fault is recognized and a so-called controlled cleaner cut is then initiated. The thread error type is also recorded and signaled.

In a second step 120, a thread search program associated with this signaled yarn error type is then called up from a memory unit 8 and finally, in a third step 130, the detection of the thread end that has accumulated is carried out by means of the suction nozzle 14 with the thread search parameters stored in the called thread end search program.

LIST OF REFERENCE SIGNS [0071]

place of work

Spinning cops

up bobbin

yarn

Cheese transport device

Coil and tube transport system

transport trays

storage unit

Kopszuführstrecke

storage line

Transverse transport paths

Tube return path

unwinding position

suction nozzle

gripper tube

Yarn joiner

yarn tensioner

contraption

spooling device

CH 714 064 A2

creel

swivel axis

grooved drum

suction

axis

Rotary actuator

winding head

suction slot

axis of rotation

Gripper tube flap

lower thread

line

line

end positions

end positions

100 procedures

110 First step

120 Second step

130 third step

Claims (10)

claims 1. Device (18) for cleaning yarn defects categorized into different types of yarn defects from a yarn (4), the device (18) having a measuring head for measuring at least one predefinable yarn parameter and being adapted if there is a deviation from a value range assigned to the yarn parameter signaling a yarn error and the yarn error type and initiating a cleaner cut based on the yarn error signal, by means of which the yarn error runs onto a package (3) of a textile machine producing package packages, characterized in that the device (18) is assigned a storage unit (8), in which a thread search program for a suction nozzle (14) of the textile machine designed for thread end search of an upper thread is stored for different types of thread defects, and the device (18) is adapted depending on the signaled thread fault type the assigned thread search program to detect the thread end of the upper thread that has run onto the package (3) by means of the suction nozzle (14). 2. The device (18) according to claim 1, characterized in that a detection rate of the thread search can be determined and stored for each type of thread defect and that the thread search program can be automatically adapted in the event of a detection rate deviating from a limit value. 3. Device (18) according to claim 1, characterized in that the automatic adaptation of the thread search programs is carried out individually for the corresponding work station (1), for a production group or for the entire textile machine. 4. The device (18) according to claim 1, characterized in that the storage unit (8) is formed by a job control device, a central control unit or an external storage unit. 5. Textile machine producing winding packages comprising a device (18) for cleaning yarn errors categorized into different types of yarn errors from a yarn (4), characterized in that the device (18) is designed according to one of claims 1 to 4. CH 714 064 A2 6. A method (100) for detecting a thread end of an upper thread of an upper thread of a work station (1) of a textile machine producing winding packages by means of a suction nozzle (14) of the textile machine assigned to the winding package (3), the method (100) being one comprises a first step (110) of the controlled cleaner cut after signaling a yarn error and associated yarn error type, characterized in that in a second step (120) a yarn search program associated with the signaled yarn error type is called up from a memory unit (8), and in a third step (130 ) the thread end of the upper thread that has accumulated is detected by means of the suction nozzle (14) in accordance with the thread end search program called up. 7. The method (100) according to claim 6, characterized in that a detection rate of the thread end of the upper thread is determined and stored for each yarn error type, and that the thread search program is automatically adapted in the event of a detection rate deviating from a limit value. 8. The method (100) according to claim 7, characterized in that the automatic adaptation of the thread search programs takes place individually for the corresponding work station (1), for a production group or for the entire textile machine. 9. The method (100) according to claim 7, characterized in that the storage takes place in the workstation control device, in the central control unit or in an external storage unit. 10. Storage unit (8) for retrievable storage of at least one thread search program associated with a thread defect type for detecting a textile end of an upper thread running onto a winding spool (3) of a winding spool by means of a suction nozzle (14) of the textile machine, characterized in that the storage unit (8) has a thread search program for carrying out the method (100) according to one of claims 6 to 9. CH 714 064 A2