DEVICE FOR PROVIDING A MATERIAL BAND, IN PARTICULAR A CORD BAND

Abstract

A device for providing a material band, including: an unwinding device for unwinding a material band, having two holders for receiving a respective roll of the material band, both holders being movable from a non-working position, in which a roll is received, and a working position, in which the roll is unwound; a transport device, downstream of the unwinding device, for the unwound material strip; a device for connecting a rear end of the unwound material band to a front end of the material band to be unwound; a position detection device including a sensor device for detecting sensor information which describes the position of the strip material in the holders, and a control device for detecting position information based on the sensor information. The position of the strip material to be unwound relative to the unwound strip material can be aligned as a function of the position information. The sensor information can be detected by the sensor device during the movement of the holders from the non-working position into the working position and the control device determines the position information and controls an actuator for moving the respective holder transversely to the transport direction of the transport device as a function of the position information so that the respective holder is positioned at the end of the movement into the working position so that the end of the material band to be unwound is aligned with the end of the un-wound material band.

Claims

1. A device for providing a material band, in particular a cord band, comprising: an unwinding device for unwinding a material band received in the form of a roll, comprising a first and a separate second holder for receiving a respective roll of the material band, wherein the first and the second holder are each reversibly movable from a non-working position, in which a roll is received or prepared, and a working position, in which the roll is unwound, a transport device downstream of the unwinding device for picking up the unwound material band, a device for connecting a rear end of the unwound material band located on the transport device to a front end of the material band to be unwound, a position detection device comprising a sensor device for detecting sensor information which describes the position of the band material to be unwound in the first and second holders, and a control device for detecting position information on the basis of the sensor information, wherein the position of the material band to be unwound can be aligned relative to the unwound material band as a function of the position information, wherein the sensor information can be detected by means of the sensor device during the movement of the first and second holders from the non-working position into the working position and the control device is set up to determine the position information and to control actuating means for moving the first and second holders transversely to the transport direction of the transport device as a function of the position information in such a way, that the first and second holders are positioned at the end of the movement into the working position in such a way that the end of the material band to be unwound is aligned with the end of the unwound material band.

2. The device according to claim 1, wherein the sensor device has at least one first sensor and a second sensor, of which the first sensor is arranged in the movement path of the first holder and the second sensor in the movement path of the second holder.

3. The device according to claim 2, wherein the detection device comprises at least one third sensor which is assigned to the transport device and by means of which sensor information describing position information describing the position of the end of the unwound band material in or at the transport device is detected, wherein the control device is set up to determine further position information on the basis of the sensor information and to control the actuating means of the first and second holders in dependence on the further position information.

4. The device according to claim 3, wherein the third sensor is a sensor detecting the entire width of the unwound material band.

5. The device according to claim 1, wherein the position of one or both longitudinal edges of the material band to be unwound can be determined by means of the control device as position information and/or the position of one or both longitudinal edges of the unwound material band can be determined as further position information, on the basis of which position information the actuating means can be controlled.

6. The device according to claim 5, wherein the control device is set up to determine the center position of the material band to be unwound as position information based on the position of the longitudinal edges of the material band to be unwound and/or the center position of the unwound material band as further position information based on the position of the longitudinal edges of the unwound material band and to control the actuating means in such a way that the center of the material band to be unwound is aligned with the center of the unwound material band.

7. The device according to claim 1, wherein the leading end of the material band to be unwound is arranged at a preparation bar of the first or the second holder during the movement, wherein the first and the second sensor are positioned below the plane in which the preparation bar is moved past them.

8. The device according to claim 1, wherein the two holders are arranged on a common carrier frame or on separate carrier frames, which are movable on linear guides in a direction perpendicular to the transport direction of the transport device via the actuating means, wherein the first and second sensors are arranged offset to both sides of the transport device.

9. The device according to claim 1, wherein the holders are arranged on a common rotating frame which can be rotated about an axis of rotation via drive means and can be moved transversely to the transport direction of the transport device via actuating means, wherein the first and second sensors are arranged on a circular path about the axis of rotation.

10. The device according to claim 9, wherein the two holders are arranged offset by 180 to each other on the rotating frame.

11. The device according to claim 10, wherein the first and second sensors are arranged 180 offset to each other at 90 positions between the non-working position and the working position.

12. A method for operating a device for providing a material band, in particular a cord band, comprising: an unwinding device for unwinding a material band received in the form of a roll, comprising a first and a separate second holder for receiving a respective roll of the material band, wherein the first and the second holder are each reversibly movable from a non-working position, in which a roll is received or prepared, and a working position, in which the roll is unwound, a transport device downstream of the unwinding device for picking up the unwound material band, a device for splicing a rear end of the unwound material band located on the transport device to a front end of the material band to be unwound, a position detection device comprising a sensor device for detecting sensor information which describes the position of the band material to be unwound in the first and second holders, and a control device for detecting position information on the basis of the sensor information, wherein the position of the material band to be unwound can be aligned relative to the unwound material band as a function of the position information, wherein the sensor information is detected by means of the sensor device during the movement of the first and second holders from the non-working position into the working position and the control device determines the position information and controls actuating means for moving the first and second holders transversely to the transport direction of the transport device as a function of the position information in such a way, that the first and second holders are positioned at the end of the movement into the working position in such a way that the end of the material band to be unwound is aligned with the end of the unwound material band.

13. The method according to claim 12, wherein a sensor device with at least a first sensor and a second sensor is used, of which the first sensor is arranged in the movement path of the first holder and the second sensor is arranged in the movement path of the second holder.

14. The method according to claim 13, wherein at least one third sensor is used, which is assigned to the transport device and by means of which sensor information describing position information describing the position of the end of the unwound or cut band material in or at the transport device is detected, wherein the control device determines further position information on the basis of the sensor information and controls the actuating means of the first and second holders as a function of the further position information.

15. The method according to claim 12, wherein the control device determines the position of one or both longitudinal edges of the material band to be unwound as position information and/or the position of one or both longitudinal edges of the unwound material band as further position information, based on which position information the actuating means are controlled.

16. The method according to claim 15, wherein the control device determines the center position of the material band to be unwound as position information based on the position of the longitudinal edges of the material band to be unwound and/or the center position of the unwound material band as further position information based on the position of the longitudinal edges of the unwound material band and controls the actuating means in such a way that the center of the band to be unwound is aligned with the center of the unwound band.

17. The method according to claim 12, wherein the leading end of the band to be unwound is arranged at a preparation bar of the first or the second holder during the movement, wherein the first and the second sensor detect the sensor information in a plane lying below the plane in which the preparation bar is moved past them.

18. The method according to claim 12, wherein the two holders are arranged on a common carrier frame or on separate carrier frames, which are moved on linear guides in a direction perpendicular to the transport direction of the transport device via the actuating means, wherein the first and second sensors are arranged offset to both sides of the transport device.

19. The method according to claim 12, wherein the holders are arranged on a common rotating frame which can be rotated about an axis of rotation via drive means and can be moved transversely to the transport direction of the transport device, which rotating frame is rotated to move the holders, wherein the first and second sensors are arranged on a circular path about the axis of rotation.

Description

BRIEF DESCRIPTION OF THE DRAWING

[0044] In the drawings:

[0045] FIG. 1 shows a schematic representation of a device for providing a material band, in particular a cord band,

[0046] FIG. 2 shows a schematic representation of a roll of material band with the band wound in the middle,

[0047] FIG. 3 shows a schematic representation of a roll of material band with an eccentrically wound band,

[0048] FIG. 4 shows a schematic representation of a roll with a material band to be unwound and the end of a material band that has already been unwound, wherein both material bands are to be joined together,

[0049] FIG. 5 shows a schematic representation of a device according to the invention in the form of a shuttle device with linear movement for moving the holders and changing the material band rolls, with centrally wound material bands,

[0050] FIG. 6 shows a schematic representation corresponding to FIG. 5, but with material bands wound off-center,

[0051] FIG. 7 shows a schematic representation corresponding to FIG. 5, but with narrower material bands that are to be connected to a wider material band,

[0052] FIG. 8 shows a schematic representation of a device according to the invention in the form of a rotating frame device with rotary movement for moving the holders and changing the material band rolls, with centrally wound material bands,

[0053] FIGS. 9-14 show schematic representations to explain the change and connection process,

[0054] FIGS. 15-19 show schematic representations of the movement of a holder with an eccentrically wound material band into the working position, showing the detection of the material band via the assigned sensor and correction of the working position, and

[0055] FIGS. 20-22 show schematic representations of the movement of both holders with centrally wound material band for replacing an unwound material band roll with a new material band roll.

DETAILED DESCRIPTION OF THE INVENTION

[0056] FIG. 1 shows a schematic diagram of a device 1 according to the invention for providing a band material, in particular a cord band. The device 1 comprises an unwinding device 2 for unwinding a material band 4 held in the form of a roll 3, wherein the unwinding device 2 has separate holders, each of which serves to hold a roll 3. For reasons of clarity, only one holder with a roll 3 is shown in FIG. 1; the specific structure is described below. In any case, each holder or roll 3 can be brought into the working position shown in FIG. 1, in which the material band 4 can be unwound from the roll 3. The material band 4 is transferred from the roll 3 to a transport device 5 downstream of the unwinding device 2, which is a corresponding roller arrangement via which the material band 4 is conveyed and also unwound. Downstream of the transport device 5 is a material support 6, on which the material band 4 is transported further to the downstream processing device. The entire device 1 can be rotated about a vertical axis of rotation 7 so that the angle at which the material band 4 is fed to the downstream processing device can be varied. This processing device can, for example, be a cutting device, which is used to cut off corresponding sections of the material band 4, which are then processed further. To enable this angular adjustment, a drive device 8 is provided, by means of which the entire device 1 can be moved along a curved path around the axis of rotation 7, for which purpose the device 1 is mounted so that it can move accordingly via suitable bearing means 9.

[0057] Furthermore, a position detection device 10 comprising a sensor device 11 and a control device 12 is provided, which can also be used to control the entire operation of the operating elements of the device 1, i.e., all actuating means, drive means, etc. By means of the sensor device 12, which comprises at least two sensors, each of which is arranged in the movement path of one of the holders described below, sensor information is recorded, on the basis of which the control devices record corresponding position information on the band material 4, which, when a previous roll 3 has been unwound, is brought into the working position shown in FIG. 1 and is to be tied to the end of the unwound band. Based on this position information, the control devices then control the corresponding actuating means by which the respective holder transporting the new roll 3 is moved into the working position. This process is described in more detail below.

[0058] As described, when a new roll 3 has been brought into the working position, the leading end of the new band material 4 and the trailing end of the previous, unwound band material 4 must be joined together, preferably spliced. For this purpose, a corresponding device 13 is provided for joining the two ends, which device 13 is preferably a splicing device. This comprises a preparation bar and a splice bar, wherein the end of the new material band 4 to be unwound is arranged on the preparation bar and the end of the unwound material band 4 is arranged on the splice bar. The two ends are spliced together by moving the splice bar.

[0059] As described, the position detection device 10 comprising the sensor device 11 serves to detect sensor information describing the position of the band material to be unwound or its end. Based on this sensor information, the control device 12 is able to determine the position of the two longitudinal edges of the new material band 4 and, if necessary, the center of the new material band 4 and, based on this, to control the actuating means via which the respective holder with the new material band 4 is moved. The sensor information is recorded during the movement of the respective holder and thus of the new material band 4 from the non-working positions into the working position, as is the determination of the position data and, based on this, the control parameters via which the actuating means of the holder drive are controlled, so that the new material band is precisely aligned with respect to the end of the unwound material band 4 when it enters the working position and no subsequent correction is necessary.

[0060] A corresponding position detection and longitudinal edge determination may be necessary because, as FIGS. 2 and 3 show, the respective rolls do not necessarily have to be wound identically. FIG. 2 shows a first reel 3 comprising a reel core 14 onto which the material band 4 is wound centrally. In contrast, FIG. 3 shows a roll 3 with a spool core 14 on which the material band 4 is wound off-center. However, as FIG. 4 shows, the two material bands 4, i.e., the new material band 4 to be unwound and the outgoing, unwound material band 4, must be aligned exactly with respect to each other, either with respect to the respective longitudinal edges or the respective centers. In FIG. 4, the material band to be unwound is marked with the reference sign 4a, the unwound material band with the reference sign 4b. The material band 4a to be unwound has two longitudinal edges 15a, 16a and a band center 17a, while the unwound material band 4b has two longitudinal edges 15b, 16b and a band center 17b. In the example shown, both material bands 4a, 4b are the same width, ideally the longitudinal edges 15a, 15b and 16a, 16b and the two centers 17a, 17b are aligned with each other. In the example, the material band 4a is wound centrally on the reel core 14a. A reel 3 as shown in FIG. 2 is therefore provided. However, if a reel 3 as shown in FIG. 3 were provided, the longitudinal edge 15a would be positioned laterally offset on the reel core 14 with the same positioning of the holder and thus of the reel 3 in the working position and thus, with the same positioning of the holder and thus of the reel 3 in the working position, would be offset to the longitudinal edge 15b transversely to the transport direction T. The same naturally also applies to the longitudinal edges 16a, 16b and the centers 17a, 17b. This transverse offset must be compensated for, which is done by detecting the position of the material band 4a or the longitudinal edges 15a, 16a, based on which position detection the holder is moved directly during its movement from the non-working positions into the working position exactly into the position aligned with respect to the end of the unwound material band 4b.

[0061] It is possible that the material band 4 may run after a certain time during the unwinding process, i.e., after the start of the material band has been spliced on. This is due to the fact that the material band 4 was wound onto the spool core 14 (coming from the calender) at an angle in a previous process or due to the operator attaching the start of the material band to the preparation bar at an angle. As a result, the material band 4 is also conveyed at a slight angle in the direction of the unwinding device 2 during unwinding. To compensate for this in the subsequent process, it is advisable to align the roller 3 with the center of the unwinding device 2. This means that the center 17a of the material band 4 is not aligned with the band center 17b of the unwound material band 4b, but with the center of the unwinding device 2. Centers 17a and 17b are then slightly offset from each other, but this is compensated for in the subsequent process. The control device 12 can be used to take into account these further offset possibilities in the positioning when changing from a non-working position to a working position.

[0062] FIG. 5 shows a schematic diagram of a device according to the invention for explaining a roll change. A first holder 18 is shown, on which a first roll 3a with a material band 4a is wound. This first holder 18 is shown in two positions, namely a non-working position, which is shown as a dashed line, and a working position, which is shown as a solid line and in which it is located adjacent to the trailing end 19 of the material band 4b already described with respect to FIG. 4. The double arrow P1 indicates this reversible linear displacement movement. A second holder 20 is also shown, on which a further roller 3c with a further material band 4c is held. This second holder 20 is located in a non-working position, which can also be called the preparation position, in which a roll 3c to be brought into the working position at a later time is held and pre-positioned in such a way that its free end, which is to be spliced to the end 19 of the material band 4b via the connecting device 13, is in a defined position, i.e., is arranged as described on the preparation bar assigned to the holder 20.

[0063] The two holders 18, 20 are arranged on a common carrier frame 21, which is shown here only as a dashed line and can be moved linearly via suitable linear guides and perpendicularly to the transport direction T via corresponding actuating means 22, such as a spindle drive controlled by a servomotor. The actuating means 22 are controlled via the control devices 12 as part of the position detection device 10, which also includes the two sensors 23, 24 shown here.

[0064] The two sensors 23, 24 are located laterally adjacent to the transport device 5 on which the material band 4 lies. The respective detection area 25, 26, as shown by the respective arrow, is directed towards the holders 18, 20. The arrangement is such that a roll to be moved from the respective non-working position into the working position or the respective band material is moved through the detection area 25, 26 of the respective sensor 23, 24, so that the sensor 23 can detect the two longitudinal edges 15a, 16a of the roll 3a in the example shown in FIG. 5, just as the sensor 24 can detect the two longitudinal edges 15c, 16c of the further roll 3c located in the second holder 20 when moving into the working position. The position of the sensors 23, 24 is such that the sensor information takes place during the movement of the respective holder and thus of the respective roller 3a, 3c and is completed before the working position has been reached. The sensor information is evaluated by the control devices 12 and the corresponding positions of the longitudinal edges as well as the band centers are determined and, based on this, corresponding control parameters for the actuating means 22 are determined, which are thus controlled in such a way that the movement of the respective holder 18, 20, which is still running, is controlled in such a way that the determined working position is approached exactly, in which the leading end 27 of the new material band 4a to be unwound is aligned with respect to the fixed-position trailing end 19 of the unwound material band 4b. The respective holder 18, 20 therefore stops only once in exactly the determined, aligned working position; no further correction of the position is required, as the band is already precisely aligned.

[0065] FIG. 5 also shows the optional possibility that a third sensor 28 is assigned to the transport device 5, which detects the longitudinal edges 15b, 16b of the material band 4b and thus the exact position of the end 19 of the material band 4b. This sensor information is also given to the control device 12, which determines the corresponding position information for the longitudinal edges 15b, 16b or the center 17b, i.e., ultimately the actual position of the end 19, with respect to which actual position the end 27 of the material band 4a or 4c is to be aligned. This actual position of the end 19 therefore represents the target position with respect to which the alignment of the movement of the holder 18, 20 and thus of the respective roller 3a, 3c should take place.

[0066] The roll 3c is measured in the same way when it is to be brought into the working position, which is the case when the material band 4a is completely unwound. In this case, the carrier frame 21 moves in the opposite direction, the holder 18 is moved from the working position to the non-working position, while the holder 20 is moved from the non-working position to the working position. Both longitudinal edges 15c, 16c pass through the detection range 26 of the sensor 24, so that corresponding edge-related sensor information is recorded, which is recorded by the control devices 12 to determine the position information for the longitudinal edges 15c, 16c or the center 17c and the corresponding control parameters for the actuating means 22 are determined, so that the roller 3c is also moved exactly into the aligned working position. In this position, the respective ends can then be connected via the connection device 13 shown.

[0067] FIG. 5 shows the device 1 or the process with material bands 4a and 4c wound centrally on the reels. FIG. 6, on the other hand, shows the device 1 according to the invention, wherein here the material band 4a is wound eccentrically on the reel core 14, the same applies by way of example to the material band 4c. Again, it is assumed that the first holder 18 is moved from the non-working position, shown as a dashed line, with the reel 3a and the material band 4a into the working position, shown as a solid line, as shown by the arrow P1. When passing through the detection area 25 of the sensor 23, the two longitudinal edges 15a, 16a are again detected, the control devices 12 again determine the corresponding position information, just as, for example, the position information can be determined simultaneously based on the sensor information of the third sensor 28. In order to align the longitudinal edges 15a, 16a with the longitudinal edges 15b, 16b of the material band 4b, as well as the two centers 17a, 17b, the holder 18 must inevitably be positioned slightly differently than in the initial example according to FIG. 5. This is because, due to the off-center winding and the resulting transverse offset 30 in relation to a centered winding, the resulting transverse offset 29, as shown in FIG. 6, which would be given if positioned in the same position as described in FIG. 5, must be compensated for. In other words, the holder 18 must move to a slightly different position as the working position than in the example shown in FIG. 5. However, in this working position as shown in FIG. 6, which is offset from the working position shown in FIG. 5, the longitudinal edges 15a, 16a are again aligned with the longitudinal edges 15b, 16b, as are the centers 17a, 17b, since the two material bands 4a, 4b are the same width here.

[0068] The same approach is adopted if the second holder 20 is to be brought into the working position; its material band 4c is also wound off-center, so that a slightly different working position must also be approached here compared to the working position shown in FIG. 5.

[0069] FIG. 7 shows an embodiment of a device 1 according to the invention, the structure of which is identical to the devices 1 described above. In contrast to the embodiment shown in FIG. 5, the two material bands 4a, 4c are significantly narrower here than the already unwound material band 4b. In the example shown, there is no central alignment, but rather an alignment with respect to a longitudinal edge, in this case the longitudinal edge 16a to the longitudinal edge 16b. The first holder 18 with the first roller 3a and the material band 4a is again moved out of the non-working position shown by the dashed line in accordance with arrow P1. Here, the material band 4a is moved through the detection area 25 of the sensor 23, the sensor again detects the two longitudinal edges 15a, 16a. The optional third sensor 28 also detects the longitudinal edges 15b, 16b. The control device 12 now determines the position information of the longitudinal edges 15a, 16a, 15b, 16b and thus the control parameters via which the actuating means 22 for moving the carrier frame 21 are to be controlled so that the two longitudinal edges 16a, 16b are aligned with each other.

[0070] As FIG. 7 also shows, the two material bands 4a, 4c are also wound off-center on the bobbin core 14 as shown by the transverse offset 30. This transverse offset 30 is also compensated, so that the resulting transverse offset 29 is determined and set via the corresponding control parameters and, despite the narrower material band 4a and off-center winding, a working position is reached in which the two longitudinal edges 16a, 16b are aligned with each other.

[0071] FIG. 8 shows an embodiment of a device 1 according to the invention, in which the two holders 18, 20 are arranged on a rotating frame which can rotate about an axis of rotation 31 and is not shown in detail in FIG. 8. The two holders 18, 20 are again shown, on each of which a roll with a material band 4a or 4c is held. The holder 18 is in the working position, i.e., the end 27 is to be spliced or has already been spliced to the end 19 of the unwound material band 4b. The holder 20 with the material band 4c, on the other hand, is in the non-working or preparation position. In order to exchange the two holders 18, 20, i.e., to move the first holder 18 from the working position into the non-working position for receiving a new roll and at the same time to move the second holder 20 with the new material band to be unwound into the working position, the entire unwinding device 2 is rotated about the axis of rotation 31, as shown by the double arrow P2. The holders 18, 20 and thus the material bands 4a, 4c consequently move on an indicated circular path 32.

[0072] Also shown here are the two sensors 23, 24 with the respective detection areas 25, 26, which are arranged adjacent to the circular path 32, in such a way that the respective longitudinal edges 15a, 16a are moved through the detection area 25 of the first sensor 23 during movement, while the longitudinal edges 15c, 16c are moved through the detection area 26 of the second sensor 24. Here again, the corresponding sensor information describing the edge position is recorded and evaluated by the control devices 12 and corresponding control parameters for controlling a drive means 33, via which the rotating frame, which is no longer shown, is rotated, are controlled. The drive means 33 is, for example, a servomotor that drives a gear wheel that meshes with a gear rim or gear segment of the carrier frame. The movement of the rotating frame is an alternating movement through 180, so that each holder 18, 20 is moved past the respective associated sensor 23, 24.

[0073] Of course, a corresponding transport device 5 is also provided here, on which the unwound material band 4b rests, as well as an optionally provided third sensor 28. Also shown is the connecting device 13, i.e., the splicing device, which serves to connect the corresponding ends 27 of the material band 4a and 19 of the material band 4b.

[0074] FIGS. 9-14 show an example of the process of a roll change. FIG. 9 shows the situation in which the roll located in the first holder 18 has been completely unwound, the end 19 of the material band 4b is hanging freely. The second holder 20 is occupied by a new roll 3c with the material band 4c, wherein the end 27 of the material band is already fixed to a preparation bar 34. Shown here is the rotating frame 35, which can be rotated about the vertical axis 31 via the drive means 33 and can be moved linearly and transversely to the transport direction T via actuating means 39, e.g., a spindle drive with a driving servomotor.

[0075] If the material band 4c is now to be provided, the rotating frame 35 is rotated, which results in both holders 18, 20 being moved around the axis of rotation 31 along the circular path 32. Here, the material band 4c runs through the detection range of the sensor 24, which in turn detects the sensor information, on the basis of which the control devices 12 then determine the exact working position into which the second holder 20 is to be brought and controls the movement of the rotating frame accordingly. This working position is shown in FIG. 10, in which it can be seen that the second holder 20 and thus the material band 4c is in the working position. It can be seen that the end 27 is arranged adjacent to the end 19 so that the splicing device 13 can splice the two ends. A movable splice bar 36 is shown, which is moved against the stationary preparation bar 34, as shown in FIG. 11 and the arrow P3 there. The two material bands 4c and 4b are now firmly connected, so that after opening the splicing device 13, i.e., retracting the splice bar 36 (see FIG. 12, arrow P4) and thus releasing the material band 4c, the band material 4c is unwound via the transport device 5 and its take-off rollers during continued transport operation.

[0076] FIGS. 10-12 also show that the first holder 18 is in the non-working position in each case, a new roll has not yet been picked up. According to FIG. 13, this is provided in the form of the roll 3a with the material band 4a and is held in the second holder 18. After picking up the roll 3a, the preparation bar 34, which is arranged on a swivel bracket 37, is swiveled over as shown by the arrow P5 and brought into the position shown in FIG. 14, in which it is assigned to the first holder 18. This position can then in turn be used to attach the free, leading edge of the new material band 4a to the preparation bar 34, so that the preparation is complete. Once the material band 4c has finally been unwound, a new cycle begins and the rotating frame 35 rotates again until the first holder 18 is back in the working position, combined of course with a corresponding position detection and activation of the actuating means 39 of the rotating frame for any immediate offset compensation.

[0077] FIGS. 15-22 show a roll change process. It is assumed that in FIG. 15 the second holder 20 with a reel 3c with a band material 4c is moved from the non-working position into the working position; for reasons of clarity, the first holder is not shown. As the figure shows, the material band 4c is wound eccentrically onto the reel core 14, which means that there is a transverse offset 30. As the movement progresses in the direction of arrow P6, one longitudinal edge 15bc of the end of the band, which is arranged on the preparatory band 34 not shown in detail, runs into the detection area 26 of the sensor 24, so that a first measuring point is provided. The longitudinal edge 15c, i.e., the first measuring point, is detected at a specific rotational position of the rotating frame 35, which can be picked up by the actuating means 33, e.g., the servomotor, so that the detection of the longitudinal edge 15c can be assigned to a specific frame position along the rotational path.

[0078] As the movement progresses, the second longitudinal edge 16c of the end fixed to the preparation bar 34 runs into the detection area 26 of the sensor 24, so that a second measuring point is given there, to which in turn a corresponding angular position of the rotating frame 35 is assigned. Corresponding measuring points are therefore provided in correlation to a respective rotating frame position, wherein the measuring points represent the specific given transverse offset 30, as they are detected at a slightly earlier point in time in relation to a central arrangement of the material band 4b, i.e., at slightly different angular positions of the rotating frame. Conversely, this would be the case if the transverse offset 30 were in the other direction. The control device 12 can determine exactly when to end the rotary movement based on the respective detected rotary frame positions, which is the case when the two longitudinal edges or longitudinal centers, which are to be aligned with respect to each other, run parallel to each other. The transverse offset is compensated by the transverse displacement of the rotating frame 35 as part of the correction movement described below.

[0079] In any case, the control devices 12 now determine the corresponding transverse offset 30 after the sensor information on both longitudinal edges is available, whereupon, see FIG. 17, the entire rotating frame 35 together with both holders 18, 20 is moved linearly, as shown by the arrow P7, i.e., a correction run begins. This corrective movement can be seen from the center line 38, which runs parallel to the transport direction T and runs through the axis of rotation 31, and from the center 17b of the unwound material band 4b. While at the beginning of the correction run, see FIG. 17, the center line 38 still runs below the line of the center 17b, the center line 38 is shifted by the increasing linear movement of the rotating frame 35 and thus of the holder 20, as already shown in FIG. 18, until the working position shown in FIG. 19 is reached, in which the determined transverse offset 30 is exactly compensated and the longitudinal edges 15c, 16c are aligned with the longitudinal edges 15b, 16b. Of course, any detection of the position of the longitudinal edges 15b, 16b via the third sensor 28 can also be taken into account during the correction run.

[0080] If, as shown in the example in FIG. 20, the band material 4c is unwound, the first holder 18 shown here, in which a new band material 4a is held, the end 27 of which is already fixed to the preparation bar 34 not shown in detail, must be brought into the working position. FIGS. 21 and 22 show the relevant movement. A swivel movement begins, as shown by arrow P8, but in the opposite direction compared to arrow P6. At a certain point in time, the longitudinal edge 15a runs through the detection range 25 of the first sensor 23, wherein a corresponding specific position of the rotating frame is assigned to this measurement point in time. It can be seen that the material band 4a is wound centrally, so that, relatively speaking, the time of detection of the longitudinal edge 15a occurs somewhat later and at a different, more advanced position of the rotating frame 35, compared with the detection of the longitudinal edge 15c as shown in FIG. 15 and the material band 4c wound off-center there. As the movement continues, the second longitudinal edge 16a also runs into the detection area 25 of the sensor 23, wherein a specific rotating frame position is also assigned to this detection point. The control devices are now in a position, on the one hand, to determine exactly the final rotating frame position in which the longitudinal edges of the material band 4a and the material band 4b or the band centers to be brought into relation with each other run parallel to each other, as well as being able to determine any offset, which results in the fact that the entire rotating frame 35 and with it both holders 18, 20 are to be moved to compensate for the transverse offset, wherein the relevant transverse movement in FIG. 22 is already indicated by the arrow P9. The control device 12 determines the corresponding control parameters and controls, on the one hand, the drive means 33, so that the rotating frame 35 is rotated accordingly, and, on the other hand, the actuating means 39, via which the rotating frame 35 is displaced transversely to correct the transverse offset.

[0081] While specific embodiments of the invention have been shown and described in detail to illustrate the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.