WO2020254954A1

WO2020254954A1 - A service robot for a ring spinning machine, a ring spinning machine and a method of operation of a service robot

Info

Publication number: WO2020254954A1
Application number: PCT/IB2020/055608
Authority: WO
Inventors: Milan Moravec; Tomás Brozek; Petr Semrád
Original assignee: Maschinenfabrik Rieter Ag
Priority date: 2019-06-19
Filing date: 2020-06-16
Publication date: 2020-12-24
Also published as: EP3987090B1; ES2972630T3; CN113939619B; CZ2019390A3; EP3987090A1; CN113939619A

Abstract

The invention is directed to a service robot (1) for a ring spinning machine for yarn production having a vertical frame (12) which is provided with a first vertical linear guide (120) and a second vertical linear guide (121). On the first vertical linear guide (120) a vertically reversibly displaceable 3D yarn handling device (13) and a vertically reversibly displaceable yarn threading device (16) are arranged and interconnected with a controllable drive and a control device (2). On the second vertical linear guide (121) a vertically reversibly displaceable cop handling device (14) and a vertically reversibly displaceable yarn end searching device (15) are arranged and interconnected with a controllable drive and a control device (2).

Description

A service robot for a ring spinning machine, a ring spinning machine and a method of operation of a service robot

Field of the Invention

The present invention is directed to a service robot for a ring spinning machine for yarn production.

The present invention is also directed to a ring spinning machine for yarn production comprising a row of identical spinning stations arranged next to each other and compris ing a service robot according to the present invention that is reversibly displaceably ar ranged along the row of spinning stations.

In addition, the invention is also directed to a method of operation of a service robot ac cording to the present invention at a spinning station of a ring spinning machine,

Background of the Invention

Ring spinning machines typically comprise a row of spinning stations arranged next to each other, each of which comprises a roving drafting system from which the roving to be processed is fed to a twisting device, from which the produced yarn is moved to a winding device where it is wound on a tube supported on a spindle, which results in cop formation, i.e. , the formation of a tube with a package.

If the yarn manufacturing process is interrupted, e.g., due to a yarn break, the yarn pro duction at the respective spinning station must be resumed. During the resumption of the spinning process at the spinning station, after interrupting the spinning process, rov ing feeding rollers which feed the roving to the drafting system are either stopped, or the feeding rollers and the drafting system continue to run and the fibers from the roving are sucked into waste downstream of the drafting system, etc.

Subsequently, the movement of the traveler on the ring on the ring bench is stopped, which is usually recorded by a sensor of the traveler movement. To resume the opera tion of the spinning station, it is necessary to find a yarn end wound on a cop package, unwind part of the yarn from the package, lead the yarn through the traveler, then through a balloon limiter, and after that also through a yarn guide (eyelet) above the balloon limiter and, finally, bring the yarn end between the end rollers of the drafting system, so that during the resumption of spinning, this end of yarn is connected to the end of roving and the yarn production at the respective spinning station is resumed. All these service operations are carried out while the ring bench and the balloon limiter are moving continuously vertically reversibly, since the ring bench and the balloon limiter carrier are common to all the spinning stations of the respective row of spinning stations and the other spinning stations of this row of spinning stations continue to produce yarn, for which the movement of the ring bench and the balloon limiter carrier is necessary.

Current ring spinning machines are largely hand-operated for several reasons. One reason for this is the limited workspace for the service mechanisms of the service robot since there are only short distances between the spinning stations (70 and 75 mm). An other reason is the difficulty in solving the functional activities of the service mecha nisms without spatial and temporal limitation of the service mechanisms within the al ready limited. And finally, yet importantly, in many parts of the world, manual service is advantageous also for price reasons.

However, various configurations of an automatic service robot for the servicing of spin ning stations on a ring spinning machine are known.

For example, EP 0 394 671 A2 discloses using a service robot to resume the working process after a break of the produced yarn at a spinning station of a ring spinning ma chine, whose handling means are arranged on separate clamping elements and their transfer to the working position is performed by an associated drive member, which leads to a higher weight of the entire service robot and increases its cost.

DD3000111 describes an embodiment, wherein vertical movement of handling means is performed by a toothed belt on a vertical guide arranged in a housing of a service robot, whereby the vertical guide and the toothed belt serve to move only one service mecha nism, which increases the complexity, weight and cost of the service robot. This is a general drawback of other known arrangements of a service robot of a ring spinning machine. Summary of the Invention

The object of the invention is therefore to overcome or at least reduce at least one of the aforementioned problems.

In this disclosure— unless otherwise specified and/or unless the particular context clearly dictates otherwise— the term“vertical” (or“vertically”) should be understood to the direction essentially perpendicular to the plane of the horizon when the service robot is in an operating condition at a ring spinning machine (i.e. the direction essentially per pendicular to the floor on which a ring spinning machine in positioned). And— unless otherwise specified and/or unless the particular context clearly dictates otherwise— the term“vertical” (or“vertically”) should be understood to include directions having an up till 20 degrees deviation with respect to the direction perpendicular to plane of the hori zon.

The object of the invention is achieved by a service robot for a spinning station of a ring spinning machine for yarn production, whose principle consists in that a 3D yarn han dling device is vertically reversibly displaceably mounted on a first vertical linear guide and further on the first vertical linear guide is vertically reversibly displaceably mounted a yarn threading device, which is adapted to thread the yarn into a traveler on a ring of the respective spinning station. A cop handling device is mounted vertically reversibly displaceably on a second vertical linear guide and further on the second vertical linear guide is vertically reversibly displaceably mounted a yarn end searching device, which is adapted to search for a yarn end on the cop.

A service robot for a ring spinning machine for yarn production according to the present invention typically comprises a vertical frame which is provided with a first vertical linear guide and a second vertical linear guide. On the first vertical linear guide a vertically reversibly displaceable 3D yarn handling device is arranged and interconnected with a controllable drive and a control device. Further on the first vertical linear guide a verti cally reversibly displaceable yarn threading device is arranged and interconnected with a controllable drive and a control device, the yarn threading device being adapted to thread yarn into a traveler of a ring of a respective spinning station of a ring spinning machine to be served by the service robot. On the second vertical linear guide a verti- cally reversibly displaceable cop handling device is arranged and interconnected with a controllable drive and a control device and further on the second vertical linear guide a vertically reversibly displaceable yarn end searching device is arranged and intercon nected with a controllable drive and a control device, the yarn end searching device be ing adapted to search for a yarn end on a cop of a spinning station of the ring spinning machine to be served by the service robot. Hence, within the context of the present in vention— unless otherwise specified and/or unless the particular context clearly dic tates otherwise— a“vertical frame” has to be understood as a frame that extends es sentially in the vertical direction.

Good results may be obtained if the 3D yarn handling device and the yarn threading device are interconnected with the same controllable drive (a first controllable drive). Thus a very cost-effective and light service robot may be obtained. However, for some applications the 3D yarn handling device and the yarn threading device may be inter connected with different controllable drives (a first and a second controllable drive). With such an embodiment, the operating speed of the service robot may be increased in cer tain cases and/or the number of operations that can be performed with the service robot can be increased.

According to a variation of the present invention, the cop handling device and the yarn end searching device are interconnected with the same controllable drive (a third con trollable drive). Thus a very cost-effective and light service robot may be obtained. However, for some applications the 3D yarn handling device and the yarn threading de vice may be interconnected with different controllable drives (a third and a fourth con trollable drive). With such an embodiment, again the operating speed of the service ro bot may be increased in certain cases and/or the number of operations that can be per formed with the service robot can be increased.

Good results can be obtained if the 3D yarn handling device is provided with a suction device for sucking in and holding the yarn (part of the yarn) during 3D yarn manipulation at the spinning station of a ring spinning machine to be served by the service robot, whereby the suction device typically comprises a mouth which can be directed to the space of the spinning station to be served by the service robot and which is spatially positionable by positioning means of the 3D handling device within the range (a spatial area of operation) defined by the height and width of the spinning station to be served. A particularly versatile service robot may be obtained if the range is defined by the height, the width and the length of the spinning station to be served.

In order to improve the positioning of the threading device with respect to the ring of a ring spinning machine to be served, it is advantageous if the threading device compris es a support finger designed to be able to rest against the upper side of a ring bench of the ring spinning machine to be served so as to lift and lower the threading device simp ly by the action of the ring bench, whereby the threading device comprises a (preferably tilting) yarn handling arm, situated obliquely with respect to the first vertical linear guide, which has a free end on which a yarn threading head is disposed with at least one yarn pin (the yarn pin designed to guide or deflect the yarn mechanically) adapted to form an oblique yarn threading section at the flange of the ring with the traveler and with at least one air nozzle to move the traveler on the ring and guide the traveler onto the oblique yarn threading section at the flange of the ring. According to a preferred embodiment, the cop handling device comprises a body and a controllably rotatable vertical spindle, which has an upper end and a lower end, the upper end being rotatably mounted in the body, where it is also coupled to a rotary drive, the lower end being provided with an expander adapted to grip a cop arranged at the respective spinning station of a ring spinning machine to be served by the service robot by contacting the inner wall of the cop tube, which is a well controllable and reliable solution. Alternatively or in addition the vertical spindle may comprise a holding element (preferably arranges at the lower end of the vertical spindle) configured to at least partially surround and hold the tube (or other parts of the cop) from the outside. Thus a particularly durable cop handling device can be obtained.

In this disclosure— unless otherwise specified and/or unless the particular context clearly dictates otherwise— the term " upper end" refers to the end that has a greater distance to the floor and the term " lower end" refers to the end that has a smaller dis- tance to the floor when the service robot is in an operating condition at a ring spinning machine standing on said floor.

According to another preferred embodiment, the cop handling device comprises a body and an expander adapted to grip a cop arranged at the respective spinning station of a ring spinning machine to be served by the service robot, whereby on the vertical frame of the robot, within the range (e.g. spatial operating range) of the expander, a vertical spindle is arranged, adapted to place the cop on it while the cop is held by the expand er, whereby the vertical spindle is at the same time situated within the range of the yarn end searching device on the cop for finding the yarn on the cop placed on the spindle, which makes it possible in particular to reduce the weight of the handling device with all the consequences for the drives, duration of the manipulation operations, etc.

To efficiently find the yarn end on a cop, the yarn end searching device on the cop may include a movable search belt which is arranged in an endless loop on the yarn end searching device, the search belt being associated by its outer surface with a vertical spindle, whereby the search belt is associated with a suction system for the yarn end to be released by the search belt from the package of yarn arranged on the cop.

Arranged on the vertical frame is a belt deflector adapted to disconnect the respective driving spindle from the drive belt that is driving the driving spindle of the ring spinning machine to be served by the service robot, so that the driving spindle can be easily and automatically disconnected.

In terms of the manufacturing process and durability, it is advantageous if the belt de flector comprises at least one movable arm at the end of which there is a rotatable de flecting pulley adapted to abut on the inner side of the drive belt and to deflect the drive belt by moving the movable arms.

Since (hand) mechanical brakes of the cop constitute a standard part of ring spinning machines at each spinning station, to improve the controllability of the spinning station and the use of the existing means of the spinning station, it may be advantageous if a control device of (hand) mechanical brake of the cop is mounted on the vertical frame of the robot at a respective spinning station of a ring spinning machine to be served by the service robot.

For improving the rigidity of the vertical frame of the service robot, as well as for enlarg ing the space for the auxiliary elements and devices of the service robot, it is advanta geous if a second extreme vertical beam is arranged on the robot frame, next to the second vertical linear guide towards the edge of the service robot, a control lever for a yarn guide being mounted swingingly (pivotably) on the beam at the respective spinning station, having a free end which is adapted to control the yarn guide of a ring spinning machine to be served by the service robot.

In addition, from a constructional and operational point of view, it may be advantageous if the control lever is designed as a crank lever which has a first end transversely mounted on a rotatable horizontal shaft of the rotary drive which is rigidly mounted on a second extreme vertical beam of the service robot as described herein.

For effective utilization of the control means of the service robot, it may be advanta geous if the control lever is also adapted to control the opening of a balloon limiter of a spinning station of a ring spinning machine at which a service operation is to be per formed by the service robot.

To improve the rigidity of the position of a cop during yarn end searching on it, it may be advantageous if during searching for the yarn end on the cop, a support for the free end of the cop (the end of the cop not directly gripped by the cop handling device) is mount ed on the robot frame.

In terms of better control of the operation and monitoring of the state, it may be advan tageous if at least one working node or working means of the service robot is provided with at least one sensor of its/their position and/or its/their state. Within the context of the present invention a working node or working means may e.g. be: a 3D yarn handling device, a cop handling device, a yarn end searching device, a yarn threading device, a belt deflector, a control lever for a yarn guide of a ring spinning machine to be served, a support for the lower end of a cop or a tube as described herein and/or components thereof.

From the point of view of the control process and because of low weight and good per formance, it is advantageous if the drives of the vertical movement of the 3D yarn han dling device, of the yarn threading device (to thread yarn into the traveler of a ring spin ning machine to be served), of the cop handling device and of the yarn end searching device on the first and second vertical linear guides are at least partially formed by stepper motors and/or linear motors connected to the control device.

From the point of view of the control process and because of low weight and good per formance, it is advantageous if the working nodes and working groups of the 3D yarn handling device, of the yarn threading device, of the cop handling means, of the yarn end searching device, of the belt deflector, of the control lever (for the yarn guide) and of the support of the lower end of the cop are coupled to mechanical and/or pneumatic and/or electronic driving units which are interconnected with the control device.

For cost-efficiency and weight reduction, it may be advantageous if the components of the service robot requiring vacuum or compressed air for their operation, especially the suction device of the 3D yarn handling device, the yarn end searching device and the yarn threading device, are connected to a source of compressed air, which is preferably mounted in the lower part of the robot. Preferably a source of compressed air may be arranged in a vertical direction below the first and the second vertical linear guides, al lowing to obtain a particularly compact service robot.

In addition, it is advantageous if components of the service robot requiring vacuum or compressed air for their operation are provided with at least one ejector connected to the source of compressed air, since vacuum/suction is thus easily and effectively gen erated even from the common source of compressed air.

In terms of the robot operation optimization, it is advantageous if the 3D yarn handling device is arranged on the first vertical linear guide above the yarn threading device, and the cop handling device is arranged on the second vertical linear guide above the yarn end searching device.

The principle of the ring spinning machine for yarn production comprising a row of iden tical spinning stations arranged next to each other, each of which comprises a roving drafting system and is adapted to guide the fibrous material through the guide, the bal loon limiter and the traveler on the ring bench to the cop, which is placed on a rotary driving spindle, whereby the service robot designed as described herein is reversibly displaceably arranged along the row of spinning stations.

The principle of the method of operation of a service robot at a spinning station of a ring spinning machine consists in that

- before finding the yarn end on the cop: the yarn guide is tilted off,

- the expander of the handling device is projected above the cop at the respective spin ning station, - the cop is gripped by the expander, lifted above the driving spindle and above the ring bench and moved into the robot to the yarn end searching device;

- the yarn end is found;

- the yarn is stretched in a defined path between the cop and the yarn end searching device - the mouth of the suction device of the 3D yarn handling device is moved to this de fined yarn path,

- the yarn is sucked into the suction device and is taken over from the yarn end search ing device, - the cop returns to the driving spindle,

- the yarn threading head is tilted towards the yarn between the cop and the suction de vice of the 3D handling device,

- an oblique yarn threading section is formed, which moves to the ring with the traveler,

- the traveler starts moving in the desired direction on the ring and is threaded onto the oblique yarn threading section, whereupon the threading head returns to its starting position in the robot and the 3D yarn handling device starts to move in a controlled manner towards the roving drafting system and simultaneously also sideways in order to guide the yarn its travel path and between the end rollers of the roving drafting system,

- the spinning process is started.

In a variation of a method of operation of a service robot as described herein may also be described as, when arranged at a spinning station of a ring spinning machine to serve the respective spinning station, the spinning station comprising a cop arranged on a driving spindle and a yarn guide including the steps of: disconnecting the drive of a driving spindle or braking the driving spindle; performing a search for a yarn end on the cop; guiding the yarn back into its travel path at the spinning station as far as between the end rollers of the roving drafting system; starting spinning. In such a variation of a method, performing the search for the yarn end on the cop comprises the steps of: tilt ing off the yarn guide of the respective spinning station; positioning the expander of the cop handling device above the cop at the respective spinning station; gripping the cop by the expander and lifting the cop above the driving spindle and the ring bench subse quently moving the cop towards the yarn end searching device. Thereby, after the yarn end has been found, the following steps are performed: stretching the yarn in a defined path between the cop and the yarn end searching device; moving the mouth of the suc tion device of the 3D yarn handling device to said defined yarn path; sucking the yarn into the suction device whereby taking it over from the yarn end searching device; re- turning the cop to the driving spindle by means of the cop handling device; tilting a yarn threading head towards the yarn between the cop and the suction device of the 3D handling device for forming an oblique yarn threading section and moving the oblique yarn threading section to the ring with the traveler; moving the traveler on the ring in a specified direction and threading the traveler onto the oblique yarn threading section. Subsequently the yarn threading head is returned to its starting position in the service robot and the 3D yarn handling device is moved in a controlled manner towards the rov ing drafting system and simultaneously also sideways in order to guide the yarn into its travel path and between the end rollers of the roving drafting system and subsequently the spinning process is resumed.

To improve the process of searching for the yarn end on the cop, it may be advanta geous if before performing the search for the yarn end on the cop, a free end of the cop rests against a support arranged at the vertical frame of the service robot.

For the sake of better ease of operation, it is advantageous if the yarn guide is tilted off by pushing a free end of a control lever swingingly (pivotally) mounted on the service robot and, optionally, a balloon limiter of the spinning station to be served is opened due to the yarn guide being tilted off.

The advantages of this solution include an economical spatial and weight arrangement of the service robot which allows to perform service operations on ring spinning ma chines in which the spinning stations are arranged with a very small spacing between each other. Furthermore, it leads to saving drive means and shortens the time needed for performing service operations at the spinning station of the ring spinning machine. Another advantage is reducing manufacturing costs and operational expenses of the service robot.

Brief Description of Drawings

The herein described invention will be more fully understood from the detailed descrip tion of the given herein below and the accompanying drawings, which should not be considered as limiting to the invention described in the appended claims. Fig. 1 schematically shows an oblique front view of an arrangement of a service robot;

Fig. 2 schematically shows a rear view of an arrangement of the robot handling means and their driving means;

Fig. 3 schematically shows a side view of a spinning station and a spindle drive inter rupter on the robot;

Fig. 4 schematically shows an arrangement of a tiltable yarn guide above the working position of the cop;

Fig. 5 schematically shows an arrangement of the tiltable yarn guide with a control of the opening of a balloon limiter;

Fig. 6 shows an example of an arrangement of a cop handling device with respect to the cop at the spinning station;

Fig. 7 schematically shows an example of an arrangement of a yarn end searching device on a cop package;

Fig. 8 schematically shows an example of an arrangement of a suction device and a yarn handling device on the robot;

Fig. 9 schematically shows an example of an arrangement of a device for threading the yarn into the traveler.

Detailed Description of the Invention

The invention will be described with reference to an exemplary embodiment of a service robot 1 for a yarn producing ring spinning machine.

The foregoing summary, as well as the following detailed description of the preferred embodiments, is better understood when read in conjunction with the appended draw ings. For the purposes of illustrating the invention, an embodiment that is presently pre ferred, in which like numerals represent similar parts throughout the several views of the drawings, it being understood, however, that the invention is not limited to the specific methods and instrumentalities disclosed. The ring spinning machine comprises a row of identical spinning stations arranged next to each other, whereby each of the spinning stations comprises, as schematically shown in Fig. 3, a roving drafting system 0, from which the fibrous material 01 , which is delivered to the drafting system 0 from an unillustrated supply bobbin, is guided through a yarn guide 02, a balloon limiter 03 and a traveler 04, which is movable on a ring 05 mounted on a ring bench 06, here vertically reversibly displaceably, as far as to a cop 07 on which the fibrous material 01 is now wound as twisted yarn material. The balloon limiter 03 is here vertically reversibly displaceable together with the ring bench 06. The cop 07, which is a tube 070 with a yarn package, is placed on a driving spindle 08 which is rotatably mounted in a frame 09 of the machine, whereby it is driven, here, for exam ple, by means of a drive belt 090. In an unillustrated exemplary embodiment, the driving spindle 08 is provided with an individual drive, e.g. with a built-in electric motor.

The service robot 1 is arranged reversibly displaceably along the row of spinning sta tions, e.g., on a track 10. In the exemplary embodiment shown, the track 10 is associat ed with a position sensor system 11 along the row of spinning stations to control and stop the movement of the service robot 1 at the respective spinning station requiring a service operation. In an unillustrated exemplary embodiment, the system for controlling the movement of the service robot 1 along the row of spinning stations and for stopping the service robot 1 at the particular spinning station is formed by another suitable meth od, e.g. by arranging the sensors of the position sensor system 11 opposite the rigid part of the mounting of the driving spindle 08 at each spinning station, when this rigid part of the mounting of the driving spindle 08 of each spinning station is directly sensed. In another unillustrated exemplary embodiment, the system for controlling the move ment of the service robot 1 along the row of the spinning stations and for stopping the service robot 1 at the respective spinning station is created as a combination of the above-mentioned arrangements or even as another arrangement.

When a yarn break occurs during producing and winding yarn, this fact is recorded by an unillustrated sensor arranged at the spinning station and this information is passed to a control unit of the machine which, after evaluating the information from other spinning stations and the information from the service robot 1 , decides to move the service robot 1 to the respective spinning station to perform a service operation.

The service robot 1 comprises a vertical frame 12 in which a first vertical linear guide 120 and a second vertical linear guide 121 are mounted, on which some service devic es of the spinning station are vertically reversibly displaceably mounted, whereby these vertically movable service devices are coupled to a controllable drive, e.g., by means of endless toothed belts which are at one end of the first and second vertical linear guides 120, 121 wrapped around a drive pulley which is coupled to a rotary drive, whereby at the other end of the first and second vertical linear guides 120, 121 the belts are wrapped around a tensioning and freely rotatable pulley, as is described in more detail in Czech patent application CZ PV 2018-35.

On the first vertical linear guide 120, a 3D yarn handling device 13, is mounted vertically reversibly displaceably, adapted to suck and hold the yarn and to handle the yarn spa tially. The 3D yarn handling device 13, which is shown in detail in Fig. 8, is provided with a suction device 130 for sucking and holding the yarn during the 3D manipulation (i.e. a manipulation (e.g. displacement) in space) with the yarn at the spinning station, whereby a mouth 1300 of the suction device 130 is directed to the area of the spinning station being serviced, i.e. to the space before the front side of the service robot 1. In addition, the mouth 1300 of the suction device 130 is spatially adjustable by means of the spatial positioning means of the 3D handling device 13 in coordination with the lifting and lowering of the handling device 13 on the first vertical linear guide 120 within the necessary range determined by the height and width of the spinning station. The 3D yarn handling device 13 is designed, for example, according to Czech patent application CZ PV 2018-48 or according to Czech patent application CZ PV 2019-389.

On the first vertical linear guide 120, a yarn threading device is further mounted vertical ly displaceably, adapted to thread the yarn into the traveler 04 on the ring 05 of the re spective spinning station. In the exemplary embodiment shown, the yarn threading de vice 16 is mounted on the first vertical linear guide 120 under the 3D yarn handling de- vice 13. In an unillustrated exemplary embodiment, the yarn threading device 16 on the first vertical linear guide 120 is mounted above the 3D yarn handling device 13.

The yarn threading device 16 is shown in detail in Fig. 9. The yarn threading device 16 comprises a support finger 162, by which the yarn threading device 16 rests against the upper side of the ring bench 06, whereupon it is possible to disconnect the yarn thread ing device 16 from its vertical drive on the first vertical linear guide 120 and from then the yarn threading device 16 on the first vertical linear guide 120 is lifted and lowered only due to the action and movement of the ring bench 06 and consequently the yarn threading device 16 is automatically levelled and set relative to the ring 05 with the trav eler 04 regardless of the variability of the instantaneous height position of the ring bench 06 due to the continued production of yarn at the other spinning stations of the respec tive row of spinning stations. The yarn threading device 16 comprises a yarn handling arm 160 tilting obliquely with respect to the first vertical linear guide 120. The tilting yarn handling arm 160 has a free end on which a rotatable yarn threading head 161 of yarn is mounted. The rotatable yarn threading head 161 is provided with at least one, but preferably with two yarn pins 1610 adapted to form an oblique yarn threading section at the flange of the ring 05 with the traveler 04. The rotatable yarn threading head 161 is further provided with at least one, but preferably with two unillustrated air nozzles for moving the traveler 04 in the required direction on the ring 05 and for guiding the travel er 04 to the oblique yarn threading section at the flange of the ring 05, as described in more detail in Czech patent application CZ PV 2018-34, which also describes in detail the operation and exemplary embodiments of the construction of the yarn threading de vice 16 for threading the yarn into the traveler 04 on the ring 05.

On the second vertical linear guide 121 , a cop handling device 14 is mounted vertically reversibly displaceably, which is shown in detail in Fig. 6 and which comprises a body 141. In the exemplary embodiment shown, a vertical spindle 140 is with its upper end 1400 mounted controllably rotatably by the drive 142 in the body 141. At its lower end 1401 , the spindle 140 is provided with an expander 143 adapted to grip the cop 07 ar ranged at the respective spinning station by contacting the inner wall of the tube 070. The cop handling device 14 is designed, for example, according to Czech patent appli cation CZ PV 2018-47.

In an unillustrated exemplary embodiment, only the expander is mounted on the body 141 of the handling device 14, the expander 143 being adapted to grip the cop 07 ar ranged at the respective spinning station. On the frame 12 of the service robot 1 , the vertical spindle 140 adapted to receive the cop 07 held by the expander 143 is rotatably mounted within the range of the expander 143, whereby the vertical spindle 140 is at the same time situated within the range of a yarn end searching device 15 for searching for the yarn on the cop 07 placed on the vertical spindle 140.

Further on the second vertical linear guide 121 , the yarn end searching device 15, adapted to find a yarn end on the cop 07 removed from the driving spindle 08, is mounted vertically reversibly displaceably. The yarn end searching device 15 is shown in a plan view in Fig. 7. In the exemplary embodiment shown, the yarn end searching device 15 is mounted on the second vertical linear guide 121 under the cop 07 handling device 14. Alternatively, in an unillustrated exemplary embodiment, the yarn end searching device 15 is mounted on the second vertical linear guide 121 above the cop 07 handling device 14.

The yarn end searching device 15 comprises a movable search belt 150, which is ar ranged in an endless loop on the yarn end searching device 15, whereby the movable search belt 150 is associated by its outer surface to the vertical spindle 140 with the cop 07, thereby associating the yarn end searching device 15 with the outer circumference of the yarn package on the cop 07. The search belt 150 is further associated with a suc tion system 151 sucking the yarn released by the search belt 150 from the package on the cop 07, since the search belt 150 during searching for the yarn end on the cop 07 by its outer surface "gently" rubs the package on the cop 07. To improve the process of finding the yarn end on the cop 07, an auxiliary suction device (not shown) is associated with the inner side of the search belt 150 in the area in which the belt 150 rubs the package on the cop 07. For example, the yarn end searching device 15 as such is con structed according to Czech patent application CZ PV 2016-746. If the ring spinning machine is not provided with individual drives of the driving spindles 08, but is provided with a belt drive, or, optionally, with a belt drive common to the driv ing spindles 08 of at least two adjacent spinning stations, then a belt deflector 17 is mounted on the frame 12, ideally at the level corresponding to the position of the belts 090 of the drive of the driving spindle 08 at the respective spinning station, whereby the belt deflector 17 is adapted to disconnect the drive of the respective driving spindle 08, e.g. by moving away the drive belt 090 from the respective driving spindle 08. As a re sult, this driving spindle is disconnected from the drive and stops together with the cop 07 placed on it. In an exemplary embodiment, the belt deflector 17 comprises at least one movable arm 170 at the end of which there is a rotatable deflecting pulley 171 adapted to abut on the inner side of the drive belt 090 and to deflect the drive belt 090 by moving the movable arms 170 in the desired direction. In an unillustrated exemplary embodiment, a control device of a manual mechanical brake of the cop 07 is mounted on the vertical frame 12 of the service robot 1. The (manual) mechanical brake of the cop 07 is a standard component of the structure of the ring spinning machine. Conse quently, the manual mechanical brake of the cop 07 at the respective spinning station of the machine is controlled by the service robot 1.

In the exemplary embodiment shown, the frame 12 of the service robot 1 further com prises a first extreme vertical beam 122 and a second extreme vertical beam 123. Addi tional extreme vertical beams may be present. The first and the second extreme vertical beam 122, 123 each are disposed between the adjacent first and second vertical linear guides 120, 121 and the side edge 124 of the vertical frame of the service robot 1.

On the second extreme vertical beam 123 a control lever 18 for the yarn guide 02 is pivotally mounted into the space of the spinning station which is being serviced, as shown in Fig. 1. The control lever 18 has a free end 180 and is adapted to abut by this free end 180 on the control end 0200 of the holder 020 of the yarn guide 02, to apply pressure thereto and rotate the holder 020 of the yarn guide 02 to its raised position indicated by a dashed line in Fig. 3. In their raised position, both the guide 02 and its holder 020 are situated outside the ground plan of the cop 07 and thus do not interfere with the manipulation with the cop 07 by the cop handling device 14. In the exemplary embodiment shown, the control lever 18 is designed as a crank lever whose first end 181 is transversely mounted on a rotatable horizontal pin 182 coupled to a rotary drive 183 which is rigidly mounted on the second extreme vertical beam 123. The control lev er 18 is cranked so that when tilted by its free end into the space of the spinning station being serviced to move the yarn guide 02 to its raised position, it does not interfere with the vertical movement and the overall operation of both the cop 07 handling device 14 and the yarn end searching device 15. The in this embodiment tiltable yarn guide 02 may be designed as e.g. shown in Czech patent application CZ PV 2018-50.

Fig. 5 shows a coupling of the holder 020 of the tiltable yarn guide 02 by a Bowden ca ble 030 to the drive of the opening of the balloon limiter 03, wherein the holder 020 of the yarn guide 02 is tilted off due to the action of the control lever 18, simultaneously the first horizontal pin 031 and the second horizontal pin 032 can be rotated via the Bowden cable 030, which results in the rotation of a first half 0310 and a second half 0320 of the balloon limiter 03, resulting in an opening of the balloon limiter 03, which in an opened state does not hinder manipulation with the cop 07 by the handling device 14.

On the frame 12 is further mounted a support 19 for the lower end of the cop 07 or the tube, during searching for the yarn end on the cop 07. In an embodiment shown, the support 19 comprises a tilting arm 190 with an unillustrated support surface for the low er end of the cop 07 or the tube, whereby the support 19 is arranged on the second ex treme vertical beam 123 under (in a vertical direction) the control lever 18 for the yarn guide 02.

To improve the control of the service robot 1 , at least some working nodes and groups 13, 14, 15, 16, 17, 18, 19 may be provided with preferably at least one sensor to acquire their spatial position and/or state.

The drives of the vertical movement of the 3D yarn handling device 13, of the threading device 16 of yarn into the traveler 04, of the cop 07 handling device 14 and of the yarn end searching device 15 on the first and second vertical linear guides 120, 121 are formed by stepper motors and/or linear motors, which are highly controllable means with a favorable performance-to-weight ratio. These drives are provided with means for controlling their speed and/or position and/or direction of movement to further improve the controllability of the service robot 1 and are coupled to the control device 2, which is disposed in the lower part of the service robot 1.

The individual working nodes and working groups of the 3D yarn handling device 13, the yarn threading device 16 of the yarn into the traveler 04, of the cop handling device 14 and of the yarn end searching device 15 of the belt deflector 17, of the control lever 18 for the yarn guide 02 and of the support 19 for the lower end of the cop 07 may be coupled to mechanical and/or pneumatic and/or electronic driving units which enable the required performance to be achieved at small dimensions and low weight and which are coupled to the control device 2.

The devices which require compressed air or vacuum for their operation, in particular, the suction device 130 of the 3D yarn handling device 13, the yarn end searching de vice and the yarn threading device, are connected via unillustrated control to a common source of compressed air 3 (e.g. an air compressor with pressure tank) which in the embodiment shown arranged in the lower part of the service robot 1. The so-called ejec tors are used to generate suction or vacuum, which are connected to a compressed air source 3 which then generates vacuum or a suction effect on their suction mouth.

In the embodiment shown, a cop 4 with reserve yarn is arranged in the lower right-hand part of the service robot 1 when looking at the front side of the service robot 1 , i.e. when looking at that side of the service robot 1 , with which the service robot 1 on the machine faces the spinning station being serviced.

A preferred embodiment of a service robot 1 according to the invention operates in such a manner that the operation consists of in a first step disconnecting the drive of the driv ing spindle 08 and/or (directly) braking the driving spindle 08, finding the yarn end on the cop 07, guiding the yarn back into its travel path at the spinning station as far as between the end rollers of the roving drafting system and starting spinning. Before the yarn end is found on the cop 07, the yarn guide 02 is tilted off, the cop handling device 14 is projected above the cop 07 at the respective spinning station, the cop 07 is gripped and lifted above the driving spindle 08 and above the ring bench 06 and moved into the service robot 1 towards the yarn end searching device 15 and the yarn end is found. Subsequently, the yarn is stretched in a defined path between the cop 07 and the yarn end searching device 15, whereby also the mouth 1300 of the suction device 1300 of the 3D yarn handling device 13 is moved to this defined yarn path. Afterwards, the yarn is sucked into the suction device 130 and taken over from the yarn end searching device 15. Thereafter, the cop 07 returns onto the driving spindle 08, the yarn threading head 161 is tilted towards the yarn between the cop 07 and the suction device 130 of the 3D yarn handling device 13, forming an oblique yarn threading section which slides to the ring 05 with the traveler 04 which starts to move in the desired direction on the ring 05 and is threaded onto the oblique yarn threading section. Afterwards, the yarn threading head 161 returns to its starting position in the service robot 1 and the 3D yarn handling device 13 starts to move in a controlled manner towards the roving drafting system 0 and simultaneously also sideways to guide the yarn into its travel path and between the end rollers of the roving drafting system and then the spinning process be gins.

In the embodiment shown, upon arrival of the service robot at the spinning station re quiring a service operation, i.e. at the spinning station after a yarn break, the driving spindle 08 of this spinning station, is disconnected, e.g. by switching off the individual drive or by the swinging movement of the belt deflector 17, which by its pulley 171 de flects the drive belt 090 from the driving spindle 08, or, optionally, the driving spindle 08 is braked by automatic activation of the mechanical brake of the cop 07 by an unillus trated actuator on the service robot 1. Meanwhile, the control lever 18 for the yarn guide 02 swings towards the space of the serviced spinning station, pushes on the control end 0200 of the holder 020 of the yarn guide 02, and rotates the yarn guide 02 to its raised position (indicated by a dashed line in Fig. 3), in which both the yarn guide 02 and its holder 020 are situated outside the ground plan of the cop 07. As the yarn guide 02 is lifted, the balloon limiter 03 is opened, whereupon the cop 07 handling device 14 at the spinning station is projected above the cop 07, which has meanwhile stopped, and by moving on the second vertical linear guide 121 downwards, it inserts the lower end 1401 of the vertical spindle 140 provided with an expander 143 in the inner space of the tube 070 of the cop 07, thereby gripping the cop 07. Alternatively or in addition, a hold- ing element which surrounds and holds the tube 070 (or other parts of the cop) from the outside may be arranged at the lower end of the vertical spindle 140. Subsequently, the spindle 140 with the cop 07 attached to it is lifted above the driving spindle 08 and above the ring bench 06 and moves towards the service robot 1 to the yarn end search ing device 15 acting on the cop 07. The tilting arm 190 of the support 19 for the lower end of the cop 07 swings and the lower end of the cop 07 rests against an abutment surface on this tilting arm 190. The yarn end searching device 15 acting on the cop 07 finds the yarn end and sucks it into its suction system 151. As a result, the yarn is stretched in a defined path between the cop 07 and the yarn end searching device 15 acting on the cop 07. At this defined yarn path between the cop 07 and the yarn end searching device 15 acting on the cop 07, the 3D yarn handling device 13 arrives through the mouth 1300 of its suction device 130, sucks in the yarn and takes it over from the yarn end searching device 15 acting on the cop 07. Now the yarn is stretched between the cop 07 and the mouth 1300 of the suction device 130 of the 3D yarn han dling device 13, the cop 07 being still held by the cop handling device 14, which now moves back to the spinning station and places the cop 07 from the top onto the driving spindle 08, which is still disconnected from the drive, releases the cop 07 and moves back into the service robot 1. Simultaneously with the return of the cop 07 onto the driv ing spindle 08, the 3D yarn handling device 13 moves downwards so that the yarn be tween the cop 07, which is now back on the driving spindle 08, and the mouth 1300 of the suction device 130 of the 3D yarn handling device 13 passes through the area into which the rotatable yarn threading head 161 is subsequently tilted down at the end of the tilting yarn handling arm 160 of the yarn threading device 16 of the yarn into the traveler 04 on the ring 05. The yarn threading head 161 then forms the oblique yarn threading section and moves to the ring 05, by which means the oblique yarn threading section approaches obliquely the flange of the ring 05 on which the traveler 04 is mounted. Subsequently, due to air nozzles (not shown) acting on the yarn threading head 161 , whereby the air nozzles blow air into the space between the ring 05 and the cop 07, the traveler 04 is starts to move in the desired direction on the ring 05 and is threaded onto the oblique yarn threading section at the flange of the ring 05, as is de scribed in more detail in Czech patent application CZ PV 2018-34. After threading the yarn into the traveler 04, the yarn threading head 161 returns to its starting position out- side the working space at the spinning station and the 3D yarn handling device 13 starts to move upwards in a controlled manner and simultaneously through the mouth 1300 of its suction device 130 sideways, guiding the yarn from the cop 07, through the traveler 04, back into its travel path, i.e. to the balloon limiter 03, to the yarn guide 02 and fur- ther, as far as between the end rollers of the roving drafting system. In doing so, the 3D yarn handling device 13 guides the yarn to the balloon limiter 03 and to the yarn guide 02 according to a specific embodiment of the balloon limiter 03 either by simply guiding the yarn to the appropriate area, where the yarn gets“by itself”, e.g., to the balloon lim iter 03 by simply closing the balloon limiter 03 (e.g. as shown in Fig. 5), e.g., after the control lever 18 for the yarn guide 02 is tilted off, or the 3D yarn handling device 13 per forms a spatial movement through the mouth 1300 of its suction device 130 to thread the yarn, e.g., between overlapping ends of the first and second halves 0310, 0320 of the balloon limiter 03, or to thread the yarn into a yarn guide 02 as shown in Czech pa tent application CZ PV 2018-50, and/or into a conventional twisted yarn guide aka“pig tail or into any other type of yarn guide.. After introducing the yarn between the end roll ers of the roving drafting system, the spinning station is ready for the resumption of yarn production and the spinning-in sequence and yarn production is started, including ac tuation of the drive of the driving spindle 08. The nodes and groups of the service robot 1 move away from the spinning station and the service robot 1 moves to another spin- ning station requiring a service operation.

The invention is applicable to service robots for performing service operations at spin ning stations of yarn making textile machines, especially in ring spinning machines which exhibit extremely little space between the individual stations, and a minimum time period of a service cycle is required. Reference Numerals

0 Drafting system 13 3D yarn handling device

01 Fibrous material 130 Suction device

02 Yarn guide 1300 Mouth (of the suction device)

020 Holder of the yarn guide 35 14 Cop handling device

0200 Control end of the holder 140 Vertical spindle

03 Balloon limiter 141 Body (of the cop handling de

030 Bowden cable vice)

031 First horizontal pin 142 Drive of the vertical spindle

0310 First half of the balloon limiter 40 143 Expander

032 Second horizontal pin 1400 Upper end (of the vertical spin

0320 Second half of the balloon lim dle)

iter 1401 Lower end (of the vertical spin

04 Traveler dle)

05 Ring 45 15 Yarn end searching device

06 Ring bench 150 Search belt (of the yarn end

07 Cop searching device)

070 Tube 151 Suction system

08 Driving spindle 16 Yarn threading device

09 Frame of the machine 50 160 Yarn handling arm

090 Drive belt 161 Yarn threading head

1 Service robot 1610 Yarn pin

2 Control device 162 Support finger

3 Source of compressed air 17 Belt deflector170 Arm (of the

10 T rack 55 belt deflector)

11 Position sensor system 171 Deflecting pulley

12 Vertical frame 18 Control lever (for a yarn guide

120 First vertical linear guide of a ring spinning machine to

121 Second vertical linear guide be served)

122 First extreme vertical beam 60 180 Free end (of the control lever)

123 Second extreme vertical beam First end of the control lever 5 19 Support (for the lower end of

(crank lever embodiment) the cop or the tube)

Horizontal pin 190 Tilting arm (of the support) Rotary drive

Claims

Patent claims

1. A service robot (1 ) for a ring spinning machine for yarn production, the service robot (1 ) comprising a vertical frame (12) which is provided with a first vertical linear guide (120) and a second vertical linear guide (121 ) wherein

o on the first vertical linear guide (120) a vertically reversibly displaceable 3D yarn handling device (13) is arranged and interconnected with a controllable drive and a control device (2); and further

o on the first vertical linear guide (120) a vertically reversibly displaceable yarn threading device (16) is arranged and interconnected with a controllable drive and a control device (2), the yarn threading device (16) being adapted to thread yarn into a traveler (04) of a ring (05) of a respective spinning station of a ring spinning machine to be served by the service robot (1 );

o on the second vertical linear guide (121 ), a vertically reversibly displaceable cop handling device (14) is arranged and interconnected with a controllable drive and a control device (2); and further

o on the second vertical linear guide (121 ) a vertically reversibly displaceable yarn end searching device (15) is arranged and interconnected with a control lable drive and a control device (2), the yarn end searching device (15) being adapted to search for a yarn end on a cop (07) of a spinning station of the ring spinning machine to be served by the service robot (1 ).

2. The service robot (1 ) according to claim 1 , wherein the 3D yarn handling device (13) is provided with a suction device (130) to suck in the yarn and hold it during the 3D manipulation with the yarn at a spinning station of a ring spinning machine to be served by the service robot (1 ), whereby the suction device (130) comprises a mouth (1300), which can be directed into the space of the spinning station to be served and which is spatially positionable by positioning means of the 3D handling device (13) within the range of the height and width of the spinning station to be served.

3. The service robot (1 ) according to claim 1 or 2, wherein the yarn threading device (16) comprises a support finger (162) designed to rest against the upper side of a ring bench (06) of a ring spinning machine to be served for lifting and lowering the yarn threading device (16) simply by the action of the ring bench (06), whereby the threading device (16) comprises a yarn handling arm (160) which is tilting obliquely with respect to the first vertical linear guide (120) and which has a free end on which a yarn threading head (161 ) with at least one yarn pin (1610) is mounted, the yarn pin (1610) being adapted to form an oblique yarn threading section at the flange of the ring (05) with the traveler (04) of a ring spinning machine to be served by the service robot (1 ), and with at least one air nozzle for moving the traveler (04) on the ring (05) and for guiding the traveler (04) onto the oblique yarn threading section at the flange of the ring (05).

4. The service robot (1 ) according to any of claims 1 to 3, wherein the cop handling device (14) comprises a body (141 ) and a controllably rotatable vertical spindle (140), which has an upper end (1400) and a lower end (1401 ), the upper end (1400) being rotatably mounted in the body (141 ), where it is also interconnected with a rotary drive (142), the lower end (1401 ) being provided with an expander (143) adapted to grip a cop (07) arranged at a respective spinning station of a ring spinning machine to be served by the service robot (1 ) by contacting the inner wall of a tube (070).

5. The service robot (1 ) according to any of claims 1 to 4, wherein the cop handling device (14) comprises a body (141 ) and an expander (143) adapted to grip a cop (07) arranged at a respective spinning station of a ring spinning machine to be served by the service robot (1 ), whereby on the vertical frame (12) of the service robot (1 ), within the range of the expander (143), is rotatably mounted a vertical spindle (140) adapted to place the cop (07) on it while the cop (07) is held by the expander (143), whereby the vertical spindle (140) is situated within the range of the yarn end searching device (15) for searching for the yarn on the cop (07) placed on the spindle (140).

6. The service robot (1 ) according to any of claims 1 to 5, wherein the yarn end searching device (15) comprises a movable search belt (150), which is arranged in an endless loop on the yarn end searching device (15), the search belt (150) being associated by its outer surface with a vertical spindle (140), whereby a suction sys tem (151 ) for the yarn end released by the search belt (150) from a package of yarn arranged on the cop (07) is assigned to the search belt (150).

7. The service robot (1 ) according to any of claims 1 to 6, wherein arranged on the vertical frame (12) is a belt deflector (17) which is adapted to disconnect a respec tive driving spindle (08) of a ring spinning to be served by the service robot (1 ) from the drive belt (090).

8. The service robot (1 ) according to claim 7, wherein the belt deflector (17) compris es at least one movable arm (170) at the end of which is located a rotatable deflect ing pulley (171 ) adapted to abut on the inner side of the drive belt (090) driving the driving spindle (8) of the ring spinning machine to be served by the service robot (1 ) and to deflect the drive belt (090) by moving the movable arms (170).

9. The service robot (1 ) according to any of claims 1 to 8, wherein a control device for a mechanical brake of a cop (07) arranged at a respective spinning station of a ring spinning machine to be served by the service robot (1 ) is mounted on the frame (12) of the service robot (1 ).

10. The service robot (1 ) according to any of claims 1 to 9, wherein a second extreme vertical beam (123) is mounted on the vertical frame (12), next to the second verti cal linear guide (121 ) towards the edge of the service robot (1 ), whereby on the second extreme vertical beam (123) a control lever (18) for a yarn guide (02) of the spinning station of the ring spinning machine to be served by the service robot (1 ) is pivotably mounted, the control lever (18) having a free end (180) which is adapted to control the yarn guide (02).

11. The service robot (1 ) according to claim 10, wherein the control lever (18) is de signed as a crank lever which has a first end (181 ) which is transversely placed on a rotatable horizontal shaft (182) of a rotary drive (183) which is rigidly mounted on the second extreme vertical beam (123).

12. The service robot (1 ) according to claim 10 or 11 , wherein the control lever (18) is also adapted to control the opening of a balloon limiter (03) of a spinning station of a ring spinning machine at which a service operation is to be performed by the ser vice robot (1 ).

13. The service robot (1 ) according to any of claims 1 to 12, wherein a support (19) for a free end of a cop (07) of a ring spinning machine to be served by the service ro bot (1 ) is mounted on the vertical frame (12) of the service robot (1 ) during search ing for the yarn end on the cop (07).

14. The service robot (1 ) according to any of claims 1 to 13, wherein at least one work ing node or working group (13, 14, 15, 16, 17, 18, 19) of the service robot (1 ) is provided with at least one sensor of its/their position and/or state.

15. The service robot (1 ) according to any of claims 1 to 14, wherein the drives of the vertical movement of the 3D yarn handling device (13), of the yarn threading device (16), of the cop handling device (14) and of the yarn end searching device (15) on the first and second vertical linear guides (120, 121 ) are at least partially formed by stepper motors and/or by linear motors connected to the control device (2).

16. The service robot (1 ) according to any of claims 1 to 15, wherein the working nodes and working groups of the 3D yarn handling device (13), of the yarn thread ing device (16), of the cop handling device (14), of the yarn end searching device (15), of the belt deflector (17), of the control lever (18) and of the support (19) for the lower end of a cop (07) are coupled to mechanical and/or pneumatic and/or electronic driving units, the driving units interconnected with the control device (2).

17. The service robot (1 ) according to any of claims 1 to 16, wherein components of the service robot (1 ) requiring compressed air or vacuum for their operation, prefer ably a suction device (130) of the 3D yarn handling device (13) or the yarn end searching device (15) and the yarn threading device (16), are connected to a com mon source of compressed air (3), which is preferably arranged in the lower part of the robot (1 ).

18. The service robot (1 ) according to claim 17, wherein components of the service robot (1 ) requiring vacuum or compressed air for their operation are provided with at least one ejector connected to the source of compressed air (3).

19. The service robot (1 ) according to any of claims 1 to 18, wherein the 3D yarn han dling device (13) is arranged on the first vertical linear guide (120) above the yarn threading device (16) and the cop handling device (14) is arranged on the second vertical linear guide (121 ) above the yarn end searching device (15).

20. A ring spinning machine for yarn production, comprising a row of identical spinning stations arranged next to each other, each of which comprises a roving drafting sys tem (01 ) and adapted to guide fibrous material (01 ) through a guide (02), a balloon limiter (03) and a traveler (04) arranged on a ring (05) that is arranged on a ring bench (06) to a cop (07) which is arranged on a rotatable driving spindle (08), comprising a service robot (1 ) according to any of claims 1 to 19, wherein the ser vice robot is reversibly displaceably along the row of spinning stations.

21. A method of operation of a service robot (1 ) for a ring spinning machine according to any one of claims 1 to 19 when arranged at a spinning station of a ring spinning machine to serve the respective spinning station, the spinning station comprising a cop (07) arranged on a driving spindle (08) and a yarn guide (02), including the fol lowing steps:

o disconnecting the drive of a driving spindle (08) or braking the driving spindle (08);

o performing a search for a yarn end on the cop (07);

o guiding the yarn back into its travel path at the spinning station as far as be tween the end rollers of the roving drafting system (0);

o starting spinning;

wherein performing the search for the yarn end on the cop (07) comprises the steps of

o tilting off the yarn guide (02) of the respective spinning station;

o positioning the expander (143) of the cop handling device (14) above the cop (07) at the respective spinning station;

o gripping the cop (07) by the expander (143) and lifting the cop (07) above the driving spindle (08) and the ring bench (06) subsequently moving the cop (07) towards the yarn end searching device (15);

wherein after the yarn end has been found comprising the steps of

o stretching the yarn in a defined path between the cop (07) and the yarn end searching device (15);

o moving the mouth (1300) of the suction device (130) of the 3D yarn handling device (13) to said defined yarn path;

o sucking the yarn into the suction device (130) whereby taking it over from the yarn end searching device (15);

o returning the cop (07) to the driving spindle (08) by means of the cop handling device (14);

o tilting a yarn threading head (161 ) towards the yarn between the cop (07) and the suction device (130) of the 3D handling device (13) for forming an oblique yarn threading section and moving the oblique yarn threading section to the ring (05) with the traveler (04);

o moving the traveler (04) on the ring (05) in a specified direction and threading the traveler (04) onto the oblique yarn threading section;

whereupon the yarn threading head (161 ) returns to its starting position in the ser vice robot (1 ) and the 3D yarn handling device (13) moves in a controlled manner towards the roving drafting system (0) and simultaneously also sideways in order to guide the yarn into its travel path and between the end rollers of the roving drafting system (0) and subsequently resuming the spinning process.

22. The method according to claim 21 , wherein before performing the search for the yarn end on the cop (07), a free end of the cop (07) rests against a support (19) ar ranged at the vertical frame (12) of the service robot (1 ).

23. The method according to claim 21 or 22, wherein the yarn guide (02) is tilted off by pushing a free end (180) of a control lever (18) pivotably mounted on the service robot (1 ) and, optionally, at least one balloon limiter (03) of the spinning station to be served is opened by tilting the yarn guide (02).