EP2368825A1 - Device for controlling coils with coiled film material - Google Patents

Abstract

The device has a sensor arrangement for detecting an end of a sheet material (12) on a coil (10), where the sheet material is wound on a core (8) of the coil. The sensor arrangement comprises an optoelectronic sensor (14) i.e. line sensor, that is arranged stationary with respect to a front end (7) of the coil on a mandrel (4) to optically detect a portion of the front end of the coil. The detected portion of the front end of the coil comprises an air gap (25) that is formed between the mandrel and the core.

Description

The present invention relates to a device for controlling coils with wound foil material. The coil comprises a core on which the film material is wound. Furthermore, the coil is associated with a sensor arrangement by means of which one end of the film material can be seen on the coil.

Furthermore, the invention relates to the use of the sensor arrangement in a packaging machine for producing containers from articles.

As in the German patent application DE 10 2008 020 299 A1 discloses a packaging machine comprises two spools with wound sheet material. One of the two bobbins is always a supply reel, which then supplies film material in the packaging process for the objects to be packaged, if the wound on the active coil film material comes to an end. For environmental and cost reasons, it is necessary to use the film material on the active coil so far that it is as far as possible unwound to the core. The end of the film on the active spool must be displayed so that the second spool (reserve spool) can be inserted into the packaging process, thus providing the film material wound on it to the packaging process.

As in the company brochure of the company Krones AG about the fully automatic packing machine "Vario Pack Pro", is one Packaging machine for a wide range of applications revealed. Here, the bottles entering the packaging machine are separated into groups. The films used to clad the individual groups are drawn off an active spool. The groups are then wrapped with the film and then go through a shrink tunnel. The individual foil blanks are separated from the wound up by the coil sheet material with a cutting knife according to the required length for the wrapping of the objects. The second spool, which is also associated with the packaging machine, is then involved in the packaging process when the film being wound on the first spool is running low.

The German patent application DE 40 21 402 A1 describes a device for controlling emptying coils. This device is mainly used in wrapping machines for articles. The control device in question consists essentially of detection means which operate in the region of a feed station of the belt at a wrapping station and / or in the vicinity of a coil and support shaft group arranged in the region of the station. These detection means serve to detect a predetermined value of an electrical impedance, which is generated by the coil and / or support shaft group and / or determine functions of at least one radial dimension of the coil and support shaft group. For this purpose, the device sits on the coil and moves with decreasing thickness of the wound on the coil sheet material in the direction of the core, or the axis of the coil so as to be measured from the Close signals on the amount of the film material, which is still wound on the spool.

The German patent application DE 195 43 246 discloses a device for controlling coils for wrapping machines. The web material (film material) is wound on a spool for the wrapping machines. The coil has a corresponding core around which the film material is wound. The spool rotates about its own axis of rotation so as to provide the wrapping material wound thereon to the wrapping machine. Associated with the coil is an optoelectronic and photosensitive sensor which is movable along a substantially radial direction of the coil during unwinding of the coil. The probe serves to detect the value of a chromatic property of a portion of the coil and to transmit a signal to the scanning device of a hue corresponding to a previously inputted pattern value. The sheet material, which is rolled up directly on the core of the spool, is colored so that as the end of the sheet material approaches the spool, the sensor registers a different color value of the sheet and thus indicates the end of the sheet material on the respective active spool.

The US patent application 2008/0142631 A1 discloses a system and method that indicates the supply of paper to a printer. The paper is rolled up on a spool around a core. The core has a fixed diameter. The paper rolled up on the core reduces the diameter over the duration of the paper's consumption by the printer. A scanning device is provided, which determines the core diameter and the paper diameter. A signal is issued when the length of the paper material rolled up on the core falls below a certain threshold.

The European patent application EP 2 093 172 A2 describes a paper supply for a printer in which the paper supply is arranged on at least one coil. The paper supply contains at least two differently arranged images for the bobbins, so that different sizes of the paper bobbins can be processed with the printer. For the final recognition of the paper, which is wound on a core, an adjustable end sensor is provided. Due to the adjustability, it is possible to adjust the sensor to the respective position of the coil.

The Japanese patent application JP 600 12 449 A describes a device for the end detection of a film material which is rolled up on a spool. For this purpose, a magnetic strip is introduced across the width of the film material, which is located in the vicinity of the end of the film material. With a detector, when rolling the film material from the spool, this magnetic strip is detected, which in turn indicates the end of the film material on the spool.

Further, in Japanese Patent Application JP 61 08 63 55 A describes an arrangement with which a junction, or the end of long sheet-like material can be detected. The connection point runs across the film web and is by means of two photo sensors detected. The photosensors are arranged in the transport direction of the film material.

The German patent application DE 44 42 154 describes a method for initiating a premature bobbin change. For this purpose, a non-contact temperature measurement is provided on the front side. Based on the measured temperature in the vicinity of the core of the coil can thus close on the amount of paper that is still on the coil, or which has already been wound on the spool.

The European patent application EP 0 730 960 A2 describes a method and apparatus for determining the end of film material rolled up on a spool. For this purpose, at least two strips are provided across the film material on the film material, which are detected by a corresponding sensor device. In one embodiment, the sensor device consists of a light source and a correspondingly assigned photodetector. By means of the sensor device, the strips are detected, which indicate the amount of the film material still rolled up onto the core.

The German patent application DE 198 47 466 A1 describes a method and apparatus for detecting defects on developable plastic sheets. The sensor is mounted on a lever arm which moves in the direction of the core in dependence on the film material unwound from the spool. The sensor detects marking elements which are mounted on the film material are and project laterally from the end face of the film material.

The object of the invention is to provide a device that detects the end of the film material on the coil cost-effective, safe and independent of parameters of the wound on a spool sheet material.

The above object is achieved by an apparatus comprising the features of claim 1.

The sheet material is wound on a core of a spool. With a sensor arrangement, the end of the film material can be detected on the coil. The sensor arrangement is designed such that it comprises at least one optoelectronic sensor. The optoelectronic sensor is arranged stationary with respect to an end face of the coil. The sensor is designed such that a part of the end face of the rotating coil is optically detectable.

The optoelectronic sensor is arranged in relation to the coil in such a way that the part of the outer circle of the rotating coil detected by the optoelectronic sensor comprises the core and the film material immediately following the core.

According to a further embodiment, the optoelectronic sensor is arranged in relation to the coil such that the part of the end face of the rotating coil detected by the optoelectronic sensor has a possible air gap between the mandrel and the core, the core itself and the film material immediately following the core.

The optoelectronic sensor is a line sensor that detects part of the outer circle of the core of the rotating coil without additional illumination. There is also provided a control with which a control signal is generated if a registered by the optoelectronic sensor level of the wound on the core sheet material below a predetermined threshold.

The sensor arrangement can have a capacitive sensor in addition to the optoelectronic sensor. The capacitive sensor is arranged to be movable radially with respect to the coil. By means of the capacitive sensor, the radial height with respect to the coil can be measured. There is also provided a control with which a control signal can be generated if the registered by the capacitive sensor radial height of the wound on the core sheet material below a predetermined threshold.

The controller can be designed such that a combined or common control signal is only output if the height registered by the optoelectronic sensor and the radial height registered by the capacitive sensor fall below the predetermined threshold value.

The use of the sensor arrangement according to the invention in a packaging machine for producing containers from articles is particularly advantageous. As already mentioned, a packaging machine two coils are associated with wound film material. There is always one the two coils the active coil. In order not to interrupt the production process of the containers unnecessarily long, it is necessary to detect the end of the film on the active coil. When determining the end of the film material on the spool, make sure that the film material is used up as much as possible. You want to avoid that the coil is replaced too early and thus produces a waste of film material that you could actually use for the packaging of containers. Upon detection of the end of the film, or the approaching end of the film material on the spool, a signal is output and it is changed to the supply reel.

By means of the optoelectronic sensor (line sensor), which is positioned stationarily in the direction of the film spool, the outer edge (circular arc) of the film core, as well as the outer diameter of the film spool is detected. A defined, once-programmed value specifies the minimum distance (threshold) of the diameter of the film spool from which a signal is output that indicates the end of the film material on the spool. If this threshold is undershot, a signal is sent to the machine control that the film material on the active coil is used up. The invention has the advantage that, regardless of the diameter of the core of the coil, a reliable detection of the end of the film material on the bobbin can be determined.

Figur 1

zeigt einen schematischen Aufbau einer Verpackungsmaschine, wie diese bereits aus dem Stand der Technik bekannt ist.

Figur 2

zeigt eine Vorrichtung zum Bestimmen des Endes von Folienmaterial auf einer Spule, gemäß dem Stand der Technik.

Figur 3

zeigt schematisch eine Seitenansicht der Folienspule mit dem zugeordneten optoelektronischen Sensor.

Figur 4

zeigt eine Stirnansicht der Folienspule mit dem zugeordneten optoelektronischen Sensor.

Figur 5

zeigt eine Detailansicht des durch den optoelektronischen Sensor registrierten Bereichs um den Kern der Spule.

Figur 6

zeigt einen kapazitiven, in radialer Richtung zur Folienspule beweglichen Sensor, der zusammen mit dem optoelektronischen Sensor das Ende des Folienmaterials auf der Spule ermittelt.

In the following, embodiments of the invention and their advantages with reference to the accompanying figures will be explained in more detail. The proportions of the individual elements to each other in the figures do not always correspond to the real Size ratios, as some shapes are simplified and other shapes are shown enlarged in relation to other elements for ease of illustration.

FIG. 1

shows a schematic structure of a packaging machine, as it is already known from the prior art.

FIG. 2

shows a device for determining the end of film material on a spool, according to the prior art.

FIG. 3

schematically shows a side view of the film coil with the associated optoelectronic sensor.

FIG. 4

shows an end view of the film coil with the associated optoelectronic sensor.

FIG. 5

shows a detailed view of the registered by the optoelectronic sensor area around the core of the coil.

FIG. 6

shows a capacitive, in the radial direction of the film coil movable sensor which detects the end of the film material on the coil together with the optoelectronic sensor.

• Figur 1 zeigt eine schematische Ansicht einer Verpackungsmaschine 100 gemäß dem Stand der Technik. Die einzelnen Gruppen 101 von Gegenständen 102 werden mit einem Folienzuschnitt 105 umhüllt. Die Folienzuschnitte 105 werden von mindestens einer Spule 10 aus Folienmaterial 12 zur Verfügung gestellt. In der in Figur 1 gezeigten Ausführungsform sind zwei Spulen 10 aus Folienmaterial 12 vorgesehen. Dabei ist eine Spule 10 die aktive Spule 10A, das bedeutet, dass von dieser Spule für die Umhüllung der Gruppen 101 der Gegenstände 102 das Folienmaterial 12 abgezogen wird. Die Vorratsspule 10V wird dann verwendet, wenn das Folienmaterial 12 auf der aktiven Spule 10A zur Neige geht. Es soll ein möglichst reibungsloser Wechsel von der aktiven Spule 10A auf die Vorratsspule 10V möglich sein.
• Figur 2 zeigt eine Sensoranordnung 2 gemäß dem Stand der Technik, mittels der ein Ende des Folienmaterials 12 auf der Spule 10 erkannt werden kann. Die Sensoranordnung 2 besteht aus einer Lichtquelle 20, welche als Laser ausgebildet ist. Die Lichtquelle 20 sendet einen Lichtstrahl 21 aus, der auf einen Detektor 22 gelangt. Der Lichtstrahl 21 gelangt nur dann zum Detektor 22, wenn eine bestimmte Menge des Folienmaterials 12 von der Spule 10 abgezogen worden ist. Das Folienmaterial 12 ist auf einen Kern 8 gewickelt. In Figur 2 ist die Situation dargestellt, dass das Folienmaterial 12₁ von der noch fast vollen Spule 10 aus Folienmaterial 12 abgezogen wird. Bei dieser Situation wird der Lichtstrahl 21 durch das Folienmaterial 12, welches auf der Spule 10 aufgerollt ist, blockiert. Ist eine bestimmte Menge des Folienmaterials 12 von der Spule 10 abgerollt, welches durch das Bezugszeichen 12₂ gekennzeichnet ist, gelangt der Lichtstrahl 21 am Umfang des noch auf dem Kern 8 befindlichen Folienmaterials 12 vorbei auf den Detektor 22. Nun kann ein Signal vom Detektor 22 ausgegeben werden, das das Ende des Folienmaterials 12 auf der Spule 10 anzeigt. Ein Nachteil dieser Anordnung des Standes der Technik ist, dass in Abhängigkeit vom Durchmesser D des Kerns 8 das Ende des Folienmaterials auf der Spule 10 nicht zuverlässig erkannt wird. So kann zum einen die Situation auftreten, dass bei einem großen Durchmesser D des Folienkerns 8 das Ende des Folienmaterials 12 auf der Spule 10 gar nicht erkannt wird. Ist der Durchmesser D des Kerns 8 jedoch klein, gelangt der Lichtstrahl 21 bereits dann auf den Detektor 22, wenn noch ausreichend Folienmaterial 10 auf dem Kern 8 der Spule 10 gewickelt ist, das noch für die Umhüllung der Artikel verwendet werden kann. In diesem Fall wird man viel noch nutzbares Folienmaterial 12 unnötig wegschmeißen.
• Figur 3 zeigt eine schematische Darstellung der Zuordnung der Sensoranordnung 2 zu einer Spule 10 aus Folienmaterial 12. Das Folienmaterial 12 ist auf einem Kern 8 einer Spule 10 gewickelt. Die Spule 10 sitzt auf einem Dorn 4, der um eine Achse 6 drehbar ist. Die Sensoranordnung 2 besteht in der in Figur 3 gezeigten Ausführungsform aus einem optoelektronischen Sensor 14. Der optoelektronische Sensor 14 ist mit einer Steuerung 5 verbunden.
  Der Zeilensensor 14 ist gegenüber einem Stirnbereich 7 der Spule 10 angeordnet. Der Zeilensensor 14 besitzt einen Erfassungsbereich 15 (siehe Figur 5) und der Zeilensensor 14 ist dabei ortsfest in Bezug auf die sich drehende Spule 10 angeordnet. Die Anordnung des Zeilensensors 14 und dessen Erfassungsbereich 15 sind dabei derart ausgebildet, dass im Erfassungsbereich 15 des Zeilensensors 14 sowohl der Kern 8 der Spule 10, als auch zumindest ein Teil des auf den Kern 8 aufgerollten Folienmaterials 12 zu liegen kommt.
• Figur 4 zeigt eine Stirnansicht der Spule 10, mit dem auf dem Kern 8 aufgerollten Folienmaterial 12. Figur 4 zeigt, dass der optoelektronische Sensor 14 (bzw. Zeilensensor) in Bezug auf die Stirnseite 7 der Spule 10 derart angeordnet ist, dass zumindest der Kern 8 und ein Teil des auf den Kern 8 aufgerollten Folienmaterials 12 erfasst wird. Bei der in Figur 4 gezeigten Ausführungsform ist der optoelektronische Sensor 14 derart ausgestaltet, dass ein Erfassungsbereich 15 des optoelektronischen Sensors 14 sich vom Dorn 4 der Spule 10 bis weit über den Kern 8 der Spule 10 erstreckt. Mit dieser Anordnung ist es möglich die Abnahme des Folienmaterials 12 auf der Spule 10 zu erfassen. Der in Figur 4 gezeigte und gestrichelte Kreis stellt einen Außenkreis 18 des Folienmaterials 12 dar, welches zu einem bestimmten Verarbeitungszeitpunkt noch auf der Spule 10 vorhanden ist. Mit der hier gezeigten Ausführungsform des optoelektronischen Sensors 14 ist es möglich, bereits die zeitliche Abnahme des Folienmaterials 12 auf der Spule 10 zu erfassen. Ebenso ist es mit dem optoelektronischen Sensors 14 möglich, einen potentiellen Luftspalt 25 zwischen dem Dorn 4 und einem Innenkreis 8_I des Kerns 8 der Spule 10 zu erfassen. Falls der auf dem Kern 8 der Spule 10 verbleibende Rest des Folienmaterials 12 eine vordefinierte Höhe H zu einem Außenkreis 8_A des Kerns 8 erreicht hat, wird dies vom optoelektronischen Sensor 14 registriert und ein entsprechendes Signal an die Steuerung 5 ausgegeben.
• Figur 5 zeigt den Ausschnitt 16 bzw. das Signalbild des Ausschnitts 16 der Stirnseite 7 der drehenden Spule 10, welches der optoelektronische Sensor 14 erfasst. Der optoelektronische Sensor 14 ist dabei derart in Bezug auf die Stirnseite 7 der Spule 10 angeordnet, dass im Erfassungsbereich 15 des optoelektronischen Sensors 14 (Zeilensensor) zumindest sowohl ein Teil des Kerns 8, als auch ein Teil des auf der Spule 10 aufgerollten Folienmaterials 12 zu liegen kommt.
  Figur 5 zeigt das Signalbild des Ausschnitts 16 des optoelektronischen Sensors 14 wie er in Figur 4 angeordnet ist. Der optoelektronische Sensor 14 erfasst einen Teil 17 des Außenkreises 18 (siehe Figur 4) der sich zeitlich verändernden Menge des Folienmaterials 12 auf der Spule 10. Die zeitliche Veränderung eines Abstandes D_T1, D_T2 ist in Figur 5 durch den gestrichelten Pfeil 30 angedeutet. Ebenso ist es möglich, mit dieser Anordnung des optoelektronischen Sensors 14 einen Teil 17 des Außenkreises 18 des auf dem Kern 8 aufgerollten Folienmaterials 12 zu erfassen. Wenn sich das auf dem Kern 8 aufgerollte Folienmaterial 12 dem Ende nähert, wird von dem Teil 17 des Außenkreises 18 die vordefinierte Höhe H bestimmt, die schließlich das Ende des auf dem Kern 8 aufgerollten Folienmaterials 12 anzeigt. Der Abstand zwischen dem Teil 17 des Außenkreises 18 des Folienmaterials 12 erreicht die vordefinierte Höhe H, die das nahe Ende des Folienmaterials 12 anzeigt. Ferner kann ebenfalls ein Teil 19_A des Außenkreises 8_A und ein Teil 19_I des Innenkreises 8_I des Kerns 8 erfasst werden. Falls sich zwischen dem Kern 8 und dem Dorn 4 ein Luftspalt 25 ausbildet, kann dies ebenfalls mit dem optoelektronischen Sensors 14 erfasst werden, da es mit dieser Ausführungsform der Anordnung des optoelektronischen Sensors 14 möglich ist, den Luftspalt 25 zwischen dem Kern 8 und dem Dorn 4 zu erfassen. Der optoelektronische Sensor 14 nimmt zusätzlich zur zeitlichen Veränderung eines Abstandes D_T1, D_T2 des Außenkreises 18 des Folienmaterials 12 auch eine Sicherungsfunktion wahr, so dass eine mögliche Störung angezeigt werden kann. Der optoelektronische Sensor 14 erkennt neben dem Außenkreis 18 des abnehmenden Folienmaterials 12, dem Außenkreis 8_A des Kerns 8, dem Innenkreis 8_I des Kerns 8 nunmehr auch den Luftspalt 25 zwischen dem Kern 8 und dem Dorn 4. Damit kann der optoelektronische Sensor 14 auch so programmiert werden, dass als Sicherheitsfunktion neben des zeitlich abnehmenden Abstandes D_T1, D_T2 des Folienmaterial zum Außenkreis 8_A des Kerns 8 auch der absolute Durchmesser aus Kern 8 und Folienmaterial 12 auf der Spule 10 abgefragt und entsprechend durch die Steuerung 5 eingestellt werden kann.
• Figur 6 zeigt eine weitere Ausführungsform zur Bestimmung der Menge des auf der Spule 10 vorhandenen Folienmaterials 12. Die Sensoranordnung 2 ist als kapazitiver Sensor 25 ausgebildet. Der kapazitive Sensor 25 liegt dabei auf dem auf der Spule 10 aufgerollten Folienmaterial 12 leicht auf oder ist zumindest in unmittelbarer Nähe zum Folienmaterial 12 angeordnet. Der kapazitive Sensor 25 ist radial in Bezug auf den Kern 8 der Spule 10 beweglich. Mit dem kapazitiven Sensor 25 ist die radiale Höhe R des auf den Kern 8 der Spule 10 befindlichen Folienmaterials 12 erfassbar. Der kapazitive Sensor 25 wandert in Abhängigkeit des von der Spule 10 abgezogenen Folienmaterials 12 näher in Richtung des Kerns 8. Der kapazitive Sensor 25 gibt ebenfalls an die Steuerung 5 ein Signal aus, wenn der kapazitive Sensor 25 eine radiale Höhe R registriert, die unter einem vorbestimmten Schwellwert liegt.

For identical or equivalent elements of the invention, identical reference numerals are used. Furthermore, for the sake of clarity, only reference symbols are shown in the individual figures, which are required for the description of the respective figure. The illustrated embodiments are merely examples of how the invention Device and the inventive method can be configured and do not represent a final limitation.

• FIG. 1 shows a schematic view of a packaging machine 100 according to the prior art. The individual groups 101 of objects 102 are wrapped with a foil blank 105. The foil blanks 105 are provided by at least one coil 10 made of foil material 12. In the in FIG. 1 In the embodiment shown, two coils 10 made of film material 12 are provided. In this case, a coil 10 is the active coil 10A, which means that from this coil for the wrapping of the groups 101 of the articles 102, the film material 12 is withdrawn. The supply spool 10V is used when the film material 12 on the active spool 10A is running low. It should be possible to change as smoothly as possible from the active coil 10A to the supply reel 10V.
• FIG. 2 shows a sensor assembly 2 according to the prior art, by means of which one end of the film material 12 can be detected on the spool 10. The sensor arrangement 2 consists of a light source 20, which is designed as a laser. The light source 20 emits a light beam 21 which reaches a detector 22. The light beam 21 only reaches the detector 22 when a certain amount of the film material 12 has been removed from the coil 10. The sheet material 12 is wound on a core 8. In FIG. 2 the situation is shown that the film material 12 _{1 is} subtracted from the still almost full bobbin 10 of film material 12. In this situation, the light beam 21 through the film material 12, which on the Spool 10 is rolled up, blocked. If a certain amount of the film material 12 is unrolled from the spool 10, which is identified by the reference numeral 12 ₂ , the light beam 21 passes on the circumference of the film material 12 still on the core 8 over to the detector 22. Now, a signal from the detector 22 which indicates the end of the sheet material 12 on the spool 10. A disadvantage of this arrangement of the prior art is that depending on the diameter D of the core 8, the end of the film material on the spool 10 is not reliably detected. Thus, on the one hand, the situation may arise that, with a large diameter D of the film core 8, the end of the film material 12 on the spool 10 is not recognized at all. However, if the diameter D of the core 8 is small, the light beam 21 already reaches the detector 22 when sufficient film material 10 is still wound on the core 8 of the coil 10, which can still be used for the wrapping of the articles. In that case, much usable sheet material 12 will be unnecessarily thrown away.
• FIG. 3 shows a schematic representation of the assignment of the sensor assembly 2 to a coil 10 of film material 12. The film material 12 is wound on a core 8 of a coil 10. The spool 10 is seated on a mandrel 4 which is rotatable about an axis 6. The sensor arrangement 2 consists in the in FIG. 3 shown embodiment of an optoelectronic sensor 14. The optoelectronic sensor 14 is connected to a controller 5.
  The line sensor 14 is arranged opposite a front region 7 of the coil 10. The line sensor 14 has a detection area 15 (see FIG FIG. 5 ) and the line sensor 14 is stationary with respect to the rotating coil 10 is arranged. The arrangement of the line sensor 14 and its detection area 15 are designed such that in the detection area 15 of the line sensor 14, both the core 8 of the coil 10, as well as at least part of the rolled up to the core 8 sheet material 12 comes to rest.
• FIG. 4 shows an end view of the spool 10, with the sheet material 12 rolled up on the core 8. FIG. 4 shows that the optoelectronic sensor 14 (or line sensor) with respect to the end face 7 of the coil 10 is arranged such that at least the core 8 and a part of the sheet material 12 rolled up on the core 8 is detected. At the in FIG. 4 In the embodiment shown, the optoelectronic sensor 14 is designed in such a way that a detection region 15 of the optoelectronic sensor 14 extends from the mandrel 4 of the coil 10 far beyond the core 8 of the coil 10. With this arrangement, it is possible to detect the decrease of the sheet material 12 on the spool 10. The in FIG. 4 shown and dashed circle represents an outer circle 18 of the film material 12, which is still present on the spool 10 at a certain processing time. With the embodiment of the optoelectronic sensor 14 shown here, it is possible to already detect the time decrease of the film material 12 on the spool 10. Likewise, it is possible with the optoelectronic sensor 14 to detect a potential air gap 25 between the mandrel 4 and an inner circle 8 _{I of} the core 8 of the coil 10. If the remainder of the sheet material 12 remaining on the core 8 of the coil 10 has reached a predefined height H to an outer circle 8 _{A of} the core 8, this becomes registered by the optoelectronic sensor 14 and outputs a corresponding signal to the controller 5.
• FIG. 5 shows the cutout 16 and the signal image of the section 16 of the end face 7 of the rotating coil 10, which detects the optoelectronic sensor 14. In this case, the optoelectronic sensor 14 is arranged in relation to the end face 7 of the coil 10 such that at least both a part of the core 8 and part of the foil material 12 rolled up on the coil 10 are in the detection area 15 of the optoelectronic sensor 14 (line sensor) lie comes.
  FIG. 5 shows the signal image of the section 16 of the optoelectronic sensor 14 as shown in FIG FIG. 4 is arranged. The optoelectronic sensor 14 detects a part 17 of the outer circle 18 (see FIG. 4 ) the time-varying amount of the film material 12 on the spool 10. The time variation of a distance D _T1 , D _T2 is in FIG. 5 indicated by the dashed arrow 30. It is likewise possible with this arrangement of the optoelectronic sensor 14 to detect a part 17 of the outer circle 18 of the film material 12 rolled up on the core 8. When the sheet material 12 rolled up on the core 8 approaches the end, the portion 17 of the outer circle 18 determines the predefined height H, which finally indicates the end of the sheet material 12 rolled up on the core 8. The distance between the part 17 of the outer circle 18 of the film material 12 reaches the predefined height H, which indicates the near end of the film material 12. Furthermore, a part 19 _{A of} the outer circle 8 _A and a part 19 _{I of} the inner circle 8 _{I of} the core 8 can also be detected. If between the core 8 and the mandrel 4 forms an air gap 25, this can also be detected with the optoelectronic sensor 14, since it is possible with this embodiment of the arrangement of the optoelectronic sensor 14 to detect the air gap 25 between the core 8 and the mandrel 4 , The optoelectronic sensor 14, in addition to the time variation of a distance D _T1 , D _{T2 of} the outer circle 18 of the film material 12, also performs a security function, so that a possible interference can be displayed. The optoelectronic sensor 14 next to the outer circle 18 of the decreasing foil material 12, the outer circle 8 _{A of} the core 8, the inner circle 8 _{I of} the core 8 now also the air gap 25 between the core 8 and the mandrel 4. Thus, the optoelectronic sensor 14 also be programmed so that as a safety function in addition to the time-decreasing distance D _T1 , D _{T2 of} the film material to the outer circle 8 _{A of} the core 8 and the absolute diameter of core 8 and film material 12 queried on the coil 10 and can be adjusted accordingly by the controller 5 ,
• FIG. 6 shows a further embodiment for determining the amount of film material 12 present on the coil 10. The sensor arrangement 2 is designed as a capacitive sensor 25. The capacitive sensor 25 rests lightly on the film material 12 rolled up on the spool 10 or is arranged at least in the immediate vicinity of the film material 12. The capacitive sensor 25 is movable radially with respect to the core 8 of the coil 10. The capacitive sensor 25 can detect the radial height R of the film material 12 located on the core 8 of the coil 10. The capacitive Sensor 25 travels closer in the direction of core 8 as a function of the foil material 12 drawn off from coil 10. Capacitive sensor 25 likewise outputs a signal to control 5 when capacitive sensor 25 registers a radial height R below a predetermined threshold value lies.

The capacitive sensor 25 serves as an additional means for the optoelectronic sensor 14, which determines the residual height H of the film material on the core 8. If the capacitive sensor 25 and the optoelectronic sensor 14 provide a signal to the controller 5, it can be assumed that the end of the film material 12 is reached on the core 8 or a bobbin change is necessary to ensure the continuous operation of the machine that consumes the sheet material 12. The optoelectronic sensor 14 then outputs a signal when the height H of the film material 12 on the core 8 falls below a certain threshold value. In parallel, the capacitive sensor 25 outputs a signal when the radial height R of the film material 12 on the core falls below a predefined threshold value. This additional fuse through the capacitive sensor 25 makes the determination of the end of the foil material 12 on the coil 10 safer.

It will be understood by those skilled in the art that the capacitive sensor 25 provides additional security for determining the end of the sheet material 12 on the spool. For the determination of the end of the film material 12 on the coil 10, however, the optoelectronic sensor 14 alone is completely sufficient.

The invention has been described with reference to a preferred embodiment. However, it will be understood by those skilled in the art that modifications or changes may be made to the invention without departing from the scope of the following claims.

Claims (11)

Device (1) for controlling a coil (10) with wound foil material (12) wound on a core (8) of the coil (10) and a sensor arrangement (2) by means of which one end of the foil material (12) the spool (10) is recognizable, characterized in that the sensor arrangement (2) comprises at least one optoelectric sensor (14) which is stationary relative to an end face (7) of the spool (10) seated on a mandrel (4) ) is arranged and is formed such that a part of the end face (7) of the rotating coil (10) is optically detectable. Device according to claim 1, wherein the optoelectronic sensor (14) is arranged with respect to the coil (10) such that the part of the end face (7) of the rotating coil detected by the optoelectronic sensor (14) has a possible air gap (25 ) between the mandrel (4) and the core (8), the core (8) itself and the film material (12) immediately following the core (8). Device according to claims 1 to 2, wherein the optoelectronic sensor (14) is a line sensor, which detects a part (19 _A ) of the outer circle (8 _A ) of the core (8) of the rotating coil (10) without additional illumination. Device according to claims 1 to 3, wherein a controller (5) is provided, with which a control signal can be generated if a of the optoelectronic sensor (14) registered height (H) between the outer circle (8 _A ) of the core (8) and an outer circle (18) of the wound on the core (8) film material (12) falls below a predetermined threshold , Device according to claims 1 to 4, wherein the optoelectronic sensor (14) is programmable such that the outer circle (18) of the decreasing foil material (12), the outer circle (8 _A ) of the core (8), the inner circle (8 _I ) the core (8) and / or the air gap (25) between the core (8) and the mandrel (4) can be detected. Device according to claim (6), wherein the optoelectronic sensor (14) assumes a safety function and also a time decreasing distance (D _T1 , D _T2 ) of the film material (12) to the outer circle (8 _A ) of the core (8) and the absolute diameter from core (8) and sheet material (12) on the spool (10) detected. Device according to claims 1 to 6, wherein the sensor arrangement (2) additionally comprises a capacitive sensor (25) which is arranged to be movable radially with respect to the coil (10). Apparatus according to claim 7, wherein by means of the capacitive sensor (25), the radial height (R) of the on the core (8) of the coil (10) located sheet material (12) is detectable. Device according to claims 7 and 8, wherein a control (5) is provided, with which a control signal can be generated, if the capacitive sensor (25) registered Radial height (R) of the wound on the core (8) film material (12) falls below a predetermined threshold. Device according to claims 4 or 7, wherein the controller (5) is designed so that a common control signal can only be output if the height (H) registered by the optoelectronic sensor (14) and the radial one registered by the capacitive sensor (25) Height (R) fall below the predetermined threshold. Use of the sensor arrangement of claims 1 to 10 in a packaging machine (100) for producing containers (101) from articles (102).

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