EP1314668B1 - Apparatus for transporting web material - Google Patents

Abstract

The machine for the transport of strip materials (1), and especially cigarette paper, has a moving tensioner (8,10) to deflect the paper path and keep the paper taut. The drive (12) for the tensioner applies a force on it at a constant level, independently of its position. The paper tension control (2) sets the operation of the tensioner drive so that its position and the driving force are independent of each other to maintain a constant paper tension. The driving force is reduced on detection of a paper irregularity, e.g. an adhesive join, and the tensioner position is set according to the speed of paper travel.

Description

The invention relates to a device for transporting strip or strip material, in particular wrapping material or tipping paper for rod-shaped articles of the tobacco processing industry, by a processing device, with an angularly movable to the transport direction of the material tension member over which the material is guided in order to produce a Tensile stress to deflect the material out of its trajectory, and with a drive means for moving the tension member and a method for controlling the tension in a transported band or strip material, in particular wrapping or tipping paper for rod-shaped articles of the tobacco processing industry, in particular using the aforementioned Device in which the material is applied at an angle to its transport direction, to be deflected to generate a tensile stress from its path of movement.

In the tobacco processing industry, it is known to produce covering strips or covering strip sections, which usually consist of more or less stiff paper, cork film or similar materials, for example mouthpiece sleeves for rod-shaped smoking articles or mouthpieces such as filters and the like, and to connect them with cigarettes. The covering strips are pulled off a covering strip bob and then deflected over an edge of a crusher, glued and separated into individual sections.

The processing device, through which the material is transported by means of the present device, may for example comprise such a crusher or consist of such a crusher. Additionally or alternatively, the material in the processing device may be otherwise processed, for example, perforated and / or printed.

In order to ensure a perfect winding or a perfect wrapping of the rod-shaped articles from such a covering strip or from individual covering strip sections, the stiffness of the lining strip is known to be reduced by the fact that the covering strip before its final shaping with his

Inner surface is pulled over a relatively sharp, knife-like edge of a usually a processing device forming crusher, whereby the covering strip is simultaneously precambered. Such a deflection around a crusher always causes a very high stress of the lining strip, which this stress in particularly critical phases, such as. during acceleration during the starting process of the production machine, or at critical points, such as e.g. at adhesion points, not grown.

In order to produce the required tensile stress in the material, usually a so-called dancer roll is used as the tension member, is guided over the material. The dancer roller is rotatably mounted at one end of a boom, while the boom with its other end to the device is arranged pivotally. By appropriate pivoting of the dancer roller, the material is deflected out of its trajectory, whereby a corresponding tensile stress arises in the material. The pivoting boom is usually resiliently biased in its maximum pivoting position. Dancer rolls of the type described are, for example, in the in DE 40 08 475 A1 disclosed device provided.

In a device of the type mentioned, the breaking process of the material and, depending on the cigarette quality at the crusher is crucially influenced by the selection and arrangement and by the control of the individual transport elements, the tipping paper supply a paper stock guide stable regardless of the quality of tamping paper and a constant paper tension when breaking regardless of the setting should ensure a bobbin brake.

That is why in the DE 199 28 867 A1 a transport device for a stripped of a bobbin wrapping material strips of the tobacco processing industry proposed, which has a first and a second Zugwalzeneinrichtung. The first draw roller device guides the tipping paper strip drawn from the reel into a loop store. The second draw roller device pulls the tipping paper strip from the loop storage via a crusher. Between the crusher and the outlet of the loop memory, a deflection roller is further arranged, which can be acted upon by a controllable negative pressure, whereby the tension of the strip breaker supplied strip is controlled to be constant. Accordingly serves in this known device which can be acted upon by a controllable negative pressure deflection roller as tension control device.

Although the known devices described above have been well proven in practice, the present invention proposes, in a device of the type mentioned above, to design the drive device in such a way that it exerts a force on the tension member which is independent of the position of the tension member a substantially constant value is adjustable.

The invention thus allows a regulation of the tension in the material to a desired constant value and, moreover, can be used in all areas of a machine where strip or strip material is transported and processed. In this case, the material is brought out of alignment by movement of the tension member and deflected around the one end of the tension member.

In a preferred embodiment, which has a tension control device for controlling the tension in the material, the tension control device controls the drive device such that the force exerted on the tension member and the position of the tension member are each independently controlled to a predetermined value.

Usually, the tension control means comprises means for detecting discontinuities, e.g. In this embodiment, the tension control device reduces the force exerted by the drive means on the tension member force compared to the value set for normal operation, when the detection device detects a discontinuity in the material. This takes into account the fact previously noted that the material is deposited at points of discontinuity such as e.g. Adhesive points, is weakened and therefore in particular a deflection around a crusher has a very high stress on the material at such critical points result.

Preferably, the tension control device deactivates the regulation of the position of the tension member when controlling the force exerted by the drive means on the tension member force to a reduced value.

Usually, at least two Zugwalzenpaare provided, wherein the tension control device controls the transport speed difference of the Zugwalzenpaare to a dependent on the position of the tension member value. Because with such an arrangement, a tensile stress in the material already arises from the fact that the second pair of drawing rollers, viewed in the transporting direction, runs a little faster behind the first pair of drawing rollers than the first pair of drawing rollers, whereby the material is tensioned between these two pairs of drawing rollers.

Depending on the operating state of the control of the position of the tension member, a specific setpoint can be specified.

At standstill of the device or even the entire machine in which the device forms part, the tension member should be movable to a rest position in which the material is under no or at least no significant tension. In this way, the material is relieved at a standstill.

In this case, the tension control device may be designed such that the tension member remains in the rest position as long as the device is at a standstill. If the drive device or even the entire device is operated electrically, the drive device should expediently be designed in such a way that it moves the tension element into the rest position and / or remains in the rest position when de-energized.

The movement of the tension member in the rest position has the advantage that in particular when changing the material, the new material can be easily threaded into the device.

A currently particularly preferred embodiment is characterized in that the drive device has a torque-controlled and adjustable to a substantially constant torque rotary drive. This design allows in a structurally particularly simple manner, a regulation of the tension in the material to a desired constant value, regardless of the position of the tension member, which for example when using a spring would not be the case, since the spring force is proportional to the spring travel and thus correspondingly variable. The rotary drive expediently has a moment-controlled rotary motor.

Another currently particularly preferred embodiment, in which the tension member is pivotable over which the material is guided, is characterized in that the tension member is pivotable by the rotary drive. By pivoting the tension member, the material is brought out of alignment and thereby deflected by one end of the tension member. Depending on the pivot position of the tension member while the material is weaker or more deflected.

Conveniently, the axis of rotation of the torque-controlled rotary motor should be substantially aligned with the pivot axis of the tension member, whereby the tension member is pivoted directly from the torque-controlled rotary motor.

Another currently particularly preferred embodiment in which the tension member comprises a rotatable dancer roller and a pivotable arm whose one end is pivotally mounted and whose free other end carries the dancer roller, characterized in that the torque-controlled rotary drive on the boom exerts a torque , whereby the deflection force of the tension member or the boom can be controlled in a particularly simple manner to a constant value.

Conveniently, the boom is attached at its one end to the output shaft of the rotary motor and extends at an angle, preferably at right angles, to the axis of rotation of the output shaft of the rotary motor.

If the processing device has a crusher which is provided with a crusher edge for the contact engagement with the material to be pulled over it, the crusher, viewed in the transport direction of the material, can optionally be arranged in front of or behind the tension member. When arranging the Breaker before the tension member, the traction force for the refraction process can be controlled directly behind the crusher by means of the tension control device. In the arrangement of the crusher behind the tension member, a decrease in the drive torque of a material transporting Zugwalzenpaares serve as an indication of a blunt crusher.

Preferably, the engagement of the crusher in dependence on the position of the tension member is controllable, since expediently by controlling the position of the tension member at the same time the effect of the crusher can be influenced. With the aid of the invention, defined geometric conditions can thus be achieved at the breaker edge. Different types of material require different deflection angles at the breaker edge.

The tension member should be movable to a rest position in which the material is disengaged from the crusher and thus does not rest on the crusher edge. In this way, not only the material is relieved in the rest position, but can also be easily threaded into the device.

With rotatable mounting of the crusher, the rotational position of the crusher can be controlled in dependence on the pivot position of the tension element. Conveniently, the axis of rotation of the crusher should be substantially aligned with the pivot axis of the tension member. In a further development of this embodiment, the axis of rotation of the crusher can be substantially aligned with the crusher edge. Preferably, the crusher is rotatably mounted on the tension member and thus forms a structural unit with the tension member. In a further development of this embodiment, the crusher on the boom, preferably on one end, rotatably attached.

Although it is already out of the DE 24 21 394 A1 known to arrange the crusher rotatably about a pivot axis; However, the pivot axis is not aligned with the breaker edge and the crusher also forms no constructive unit with the dancer roller, which in the device according to the DE 24 21 394 A1 is also included.

Alternatively, the crusher may be disconnected from the movable tension member and disposed stationary with respect to the apparatus. In a further development of this alternative embodiment, the crusher is arranged with its breaker edge at a distance from the path of movement of the material when the material is disengaged from the crusher.

Finally, it should expediently be provided a position sensor for detecting the pivot position of the tension member and a calibration device which pivots the tension member in a rest position and also in a fully deflected pivot position upon activation of the device for calibrating the position sensor. For this purpose, an end stop can be arranged for the rest position and the fully deflected pivot position.

Finally, according to a further aspect, the present invention proposes, in a method of the type mentioned at the outset, to set or regulate the force generated for the application of the material to a constant value, regardless of the degree of deflection.

Fig. 1

eine schematische zweidimensionale Darstellung einer ersten Ausführung einer Transportstrecke für band- oder streifenförmiges Material mit einer schwenkbaren Tänzerwalze-Brecher-Einheit in ihrer Arbeitsstellung;

Fig. 2

eine Fig. 1 entsprechende schematische dreidimensionale Darstellung der ersten Ausführung;

Fig. 3

eine schematische dreidimensionale Darstellung der ersten Ausführung gemäß Fig. 2 mit der Tänzerwalze-Brecher-Einheit in ihrer Ruhestellung;

Fig. 4

eine schematische dreidimensionale Darstellung einer zweiten Ausführung einer Transportstrecke für band- oder streifenförmiges Material, welches sich von der ersten Ausführung gemäß den Figuren 1 bis 3 dadurch unterscheidet, dass der Brecher stationär angeordnet ist, wobei sich die Tänzerwalze in ihrer Arbeitsstellung befindet;

Fig. 5

eine schematische dreidimensionale Darstellung der zweiten Ausführung gemäß Fig. 4 mit der Tänzerwalze in ihrer Ruhestellung; und

Fig. 6

eine schematische dreidimensionale Darstellung einer dritten Ausführung einer Transportstrecke für band- oder streifenförmiges Material ohne Brecher mit einer Tänzerwalze in ihrer Arbeitsstellung.

Hereinafter, preferred embodiments of the invention will be explained in more detail with reference to the accompanying drawings. Show it:

Fig. 1

a schematic two-dimensional representation of a first embodiment of a transport path for strip or strip-shaped material with a pivotable dancer roller crusher unit in its working position;

Fig. 2

a corresponding schematic three-dimensional representation of the first embodiment;

Fig. 3

a schematic three-dimensional view of the first embodiment of Figure 2 with the dancer roller crusher unit in its rest position.

Fig. 4

a schematic three-dimensional representation of a second embodiment of a transport path for strip or strip-shaped material, which differs from the first embodiment according to Figures 1 to 3, characterized in that the crusher is arranged stationary, wherein the dancer roller is in its working position;

Fig. 5

a schematic three-dimensional representation of the second embodiment of Figure 4 with the dancer roller in its rest position. and

Fig. 6

a schematic three-dimensional representation of a third embodiment of a transport path for strip or strip-shaped material without crushers with a dancer roller in its working position.

The transport routes shown in the figures can be used, for example, in a cigarette filter tipping machine such as e.g. However, the machine provided by the applicant under the name "MAX" and provided for a wrapping paper strip in the form of a tipping paper strip for connecting cigarettes and filters are not limited to such an application.

As shown in Fig. 1, the first embodiment of a transport path for a strip of material 1, a sensor device 2, the discontinuities, such as splices, recognizes. Connected downstream of the sensor device 2 is a first draw roller pair 4, which pulls the material strip 1 from a reel, not shown, in the direction of the arrow A. Behind the first pair of drawing rollers 4, the strip of material 1 passes through a processing station 14, whose construction is described below will be described in more detail. After exiting the processing station 14 of the strip of material 1 passes through a second pair of drawing rollers 16 and is finally deflected around a guide roller 18, to then be fed to another, not shown here, processing.

In Fig. 2, the arrangement of Fig. 1 is shown once again in a three-dimensional view, wherein the sensor device 2 and the guide roller 18 are omitted for reasons of clarity.

As can be seen from FIGS. 1 and 2, the processing station in the exemplary embodiment shown has a dancer roller 8 about which the strip of material 1 is deflected. The dancer roller 8 is rotatably supported about a central axis thereof on a leg 10a of an L-shaped double lever 10. The double lever 10 is in turn fixed to the output shaft 12a of a torque-controlled motor 12. The axis of rotation of the output shaft 12a runs parallel at a distance from the axis of rotation of the dancer roller 8. Accordingly, at least the leg 10a of the double lever 10 serves as a boom, at the free end of the dancer roller 8 is mounted.

The torque-controlled motor 12 may preferably be an electric motor.

At the double lever 10, a crusher 22 is rotatably secured so that the crusher edge 22a is aligned with the axis of rotation of the output shaft 12a of the motor 12. Thus, in the first embodiment, the crusher 22 forms a structural unit with the dancer roller 8.

While in Fig. 2, the unit of dancer roller 8 and crusher 22 is shown by corresponding pivoting of the double lever 10 by means of the motor 12 in its fully deflected working position, take in the illustration of Fig. 3, the dancer roller 8 and the crusher 22 their rest position , As can also be seen from FIG. 3, the dancer roller 8 and the breaker 22 are arranged relative to one another in such a way that, in the rest position, the material strip 1 is contactless between the dancer roller 8 and the crusher 22 is passed. In contrast, the material strip 1 is bent in the working position shown in FIG. 2 at the breaker edge 22a and guided around the dancer roller 8, so that the crusher 22 with its breaker edge 22a and the dancer roller 8 are each in touching engagement with the strip of material 1.

As a comparison of Figures 2 and 3 reveals, in the illustrated embodiment, the arrangement is such that the rotation angle for pivoting the double lever 10 between the rest position shown in FIG. 3 and the fully deflected working position shown in FIG. 2 is 180 °.

While in the rest position shown in FIG. 3, the strip of material 1 runs straight from the first Zugwalzenpaar 4 to the second Zugwalzenpaar 16, the dancer roller 8 is engaged by pivoting the double lever 10 from the rest position to a working position in engagement with the strip of material 1 between the two Zugwalzenpaaren 4 and 16 brought. This has the consequence that upon further pivoting of the double lever 10 of the strip of material 1 is deflected from its direct linear trajectory between the two Zugwalzenpaaren 4 and 16 and not only deflected around the dancer roller 8, but also in contact with the breaker edge 22a of the crusher 22 passes (see Fig. 2).

The torque-controlled motor 12 is controlled by a control device 20, which is shown schematically only in FIG. 1, but is omitted in FIGS. 2 and 3 for reasons of clarity. In this case, the motor 12 is acted upon by a constant torque, whereby the double lever 10 and thus the dancer roller 8 carried on one leg 10a is pivoted into a specific pivot position. The torque determines the tension in the strip of material 1. The greater the torque at which the motor 12 pivots the double lever 10 and thus the dancer roller 8 deflects the strip of material 1, the stronger the strip of material 1 is subjected to tensile stress.

The control device 20 controls the motor 12 such that the torque generated by the motor 12 is controlled to a predetermined value, wherein the control of the torque takes place independently of the pivotal position of the double lever 10.

In addition, the control device 20 is also linked to the Zugwalzenpaaren 4 and 16. Usually, namely, the conveying speed of the second Zugwalzenpaares 16 is a little higher than that of the first Zugwalzenpaares 4, whereby already in the strip of material 1, a tensile stress. This speed difference controls the control device 20 as a function of the pivotal position of the double lever 10 and thus the position of the dancer roller. 8

The control device 20 not only controls the torque of the motor 12, but also receives information about the rotational position of the output shaft 12a of the motor 12 and thus the pivotal position of the double lever 10. For this purpose, a position sensor, not shown, is provided, which forwards this information to the control device 20. Usually, the position sensor is integrated in the engine 12. To calibrate this position transmitter when starting the device, the motor 12 is controlled by the control device 20, that it pivots the double lever 10 first in the rest position shown in FIG. 3 and then in the fully deflected working position shown in FIG. For this purpose, two corresponding end stops can be provided, which are not shown in the figures.

At standstill of the device, the control device 20 controls the motor 12 so that the double lever 10 is pivoted to its rest position shown in FIG. In addition, the arrangement shown is made such that in the de-energized state of the device of the double lever 10 remains in its rest position. In the rest position then the strip of material 1, for example, after a change of paper type, are easily threaded.

If, during operation, the sensor device 2 detects a discontinuity, such as a bond, in the strip of material 1, controls the control device 20, the motor 12 such that the torque of the motor 12 is reduced. As a result, the pressure of the dancer roller 8 is reduced to the material strip 1 and thus the tensile stress applied thereby in the material strip 1. This is important because the bond naturally forms a weak point where the strip of material 1 can easily break. In this case, the weight of the dancer roller 8 is also to be considered. In the case of paper, the tensile stress should normally be about 7 N, for example, but only about 0.5 N for a single bond. Assuming that the weight of the dancer roller is about 2 N, a total force of about 9 N in normal operation and about 2.5 N at a splice is applied, which is easily possible by means of the torque-controlled motor 12. In another embodiment or other weight distribution, it is also conceivable that the torque to be applied at a splice changes the sign. During the reduction of the torque of the motor 12 and the resulting reduction of the tension in the strip of material 1, the position control for the double lever 10 and thus for the dancer roller 8 can also be switched off, until such time as the discontinuity, such as an adhesive point, the second Zugwalzenpaar 16 happened.

As can be seen in particular FIG. 2, a counterweight 24 is still attached to the other leg 10b of the double lever 10, which is mainly intended to pivot the double lever 10 by gravity into its rest position shown in FIG. By appropriate dimensioning of the counterweight 24 can be depending on the application but also influence the torque conditions during operation accordingly, for example, to generate in the manner described above, a counter-force of predetermined size can.

The crusher 22 may, viewed in its working position in the transport direction of the material strip 1, optionally be arranged in front of or behind the dancer roller 8. In the first embodiment shown in FIGS. 1 and 2, the crusher 22, viewed in the transport direction A of the material strip 1, is located in front of the dancer roller 8. If the transport direction is reversed so that the material strip 1 runs in the direction of the arrow A ', and laid one the sensor device 2 to the other end 1, indicated by dashed lines and the reference numeral 2 ', results in a modified embodiment, in which the crusher 22, viewed in the transport direction A', now lies behind the dancer roller 8.

By arranging the dancer roller 8, viewed in the transport direction A of the material strip according to FIG. 1, behind the breaker 22, the tensile force determining the refraction process can be directly controlled by the dancer roller 8 behind the breaker 22.

In the arrangement of the dancer roller 8, viewed in the transport direction according to dashed arrow A 'in Fig. 1, before the crusher 22, a decrease in the drive torque of the underlying Zugwalzenpaares, here the first Zugwalzenpaares 4, serve as an indication of a blunt crusher edge 22a of the crusher 22 ,

Finally, the desired value of the position of the dancer roller 8 and thus the paper angle over the breaker 22 can be specified as a brand parameter.

In Figures 4 and 5, a presently preferred second embodiment is shown, which differs from the first embodiment described above with reference to Figures 1 to 3 characterized in that - instead of a rotatable mounting by placing the double lever - the crusher 22 'of the double lever 10th 'Physically separated stationary. Accordingly, in this second embodiment, the crusher 22 'is not moved together with the dancer roller 8, but is fixed and the dancer roller 8 is pivoted by the motor 12 only in accordance with. The crusher edge 22a 'of the crusher 22' has a fixed orientation.

In the working position of the dancer roller 8 shown in FIG. 4, in the same way as in the first embodiment according to FIG. 2, the material strip 1 is pulled over the breaker edge 22a 'of the stationary breaker 22' and deflected there. In the rest position of the dancer roller 8 shown in FIG. 5, by contrast, the material strip runs 1 free from the crusher 22 ', ie at a distance from this. Accordingly, in the second embodiment, the arrangement is such that the stationary crusher 22 'at a distance from the two Zugwalzenpaare 4 and 16 directly connecting line, which forms the web of the strip of material 1 in the rest position of the dancer roller 8, sitting and in their rest position the dancer roller 8 is also located at a distance from the material strip 1. Thus, in the rest position of the dancer roller 8, the strip of material 1 runs without contact between the dancer roller 8 and the breaker 22 ', as shown in FIG. 5.

With regard to the other construction features and the scheme of the second embodiment, reference is made to the description of the first embodiment.

It should also be mentioned at this point that in the processing station 14, the material strip 1 optionally also processed in another way, for example, printed and / or perforated, can be.

Finally, it is also conceivable to realize an embodiment in which a crusher is not provided. Such a third embodiment is shown in FIG.

Thus, the third embodiment according to Figure 6 differs from the embodiments according to Figures 1 to 5 in particular in that the crusher is missing and a simple radial cantilever 10 "is provided instead of the double lever, whereby the dancer roller 8 is at the free end of this cantilever 10 "rotatably supported, while the boom 10" is fixed at its other end radially to the output shaft 12a of the torque-controlled motor 12. In the third embodiment shown in Fig. 6 - instead of the crusher - a free-running guide roller 6 is provided on the boom 10th is mounted such that its axis of rotation is aligned with the axis of rotation of the output shaft 12 a of the motor 12.

The processing station 14 shown in Fig. 6 is provided for otherwise processing of the material strip 1, in which the material strip 1 can be perforated and / or printed, for example.

The deflection roller 18 shown in Fig. 1 may also be provided in the third embodiment, but is not shown in Fig. 6.

The sensor device 2 and the control device 20 of FIG. 1 are also not shown in FIG. 6. However, the sensor device and the control device are part of the third embodiment in the same way as they are in the first and second embodiments. Therefore, with regard to the control of the motor 12 and the pivoting of the dancer roller 8, reference is made to the description previously made in connection with the first embodiment.

The arrangement of freewheeling deflection roller 6 and dancer roller 8 is made in such a way that the material strip 1 is guided without contact between the free-running deflection roller 6 and the dancer roller 8 in the rest position of the extension arm 10 "(not shown) 10 "and thus the dancer roller 8 shown in working position, in which the dancer roller 8 deflects the material strip 1 from its direct movement path between the two Zugwalzenpaaren 8 and 16, whereby the strip of material 1 also comes into contact with the free-running guide roller 6 and is deflected accordingly ,

Claims (24)

1. Apparatus for conveying band- or strip-shaped material (1), in particular wrapping material or covering paper for rod-shaped articles of the tobacco-processing industry, through a processing device (14), having at least two drawing roller pairs (4, 16) for conveying the material (1), having a tensile stress element (8, 10; 8, 10'; 8, 10"), which is disposed between the two drawing roller pairs (4, 16) and movable at an angle to the conveying direction of the material (1) and over which the material (1) is run in order to deflect the material (1) from its path of motion for the purpose of generating a tensile stress, having a drive device (12) for moving the tensile stress element (8, 10; 8, 10'; 8, 10") and having a tension regulating device (2, 20) for regulating the tensile stress in the material (1),
   characterized in that the drive device (12) is designed in such a way that it exerts on the tensile stress element (8, 10; 8, 10'; 8, 10") a force that is adjustable to a substantially constant value independently of the position of the tensile stress element (8, 10; 8, 10'; 8, 10"), and the tension regulating device (2, 20) controls the drive device (12) in such a way that the force exerted on the tensile stress element (8, 10; 8, 10'; 8, 10") and the position of the tensile stress element (8, 10; 8, 10'; 8, 10") are each adjusted independently of one another to a preset value, and regulates the difference of the conveying speed of the two drawing roller pairs (4, 16) to a value that is dependent upon the position of the tensile stress element (8, 10; 8, 10'; 8, 10").
2. Apparatus according to claim 1,
   in which the tension regulating device comprises a device (2) for detecting discontinuities, such as e.g. sticker marks, in the material (1),
   characterized in that the tension regulating device reduces the force exerted by the drive device (12) on the tensile stress element (8, 10; 8, 10'; 8, 10") if the detection device (2) detects a discontinuity in the material (1).
3. Apparatus according to claim 2,
   characterized in that, in the event of regulation of the force exerted by the drive device (12) on the tensile stress element (8, 10; 8, 10'; 8, 10") to a reduced value, the tension regulating device (2, 20) deactivates the regulation of the position of the tensile stress element (8, 10; 8, 10'; 8, 10").
4. Apparatus according to at least one of claims 1 to 3,
   characterized in that in dependence upon the operating state a specific setpoint value is selectable for the regulation of the position of the tensile stress element (8, 10; 8, 10'; 8, 10").
5. Apparatus according to at least one of claims 1 to 4,
   characterized in that in the stationary state of the apparatus the tensile stress element (8, 10; 8, 10'; 8, 10") is movable into a neutral position, in which the material (1) is under no, or at least no substantial tensile stress.
6. Apparatus according to claim 5,
   characterized in that the tension regulating device is designed in such a way that the tensile stress element (8, 10; 8, 10'; 8, 10") remains in the neutral position so long as the apparatus is in a stationary state.
7. Apparatus according to claim 5 or 6,
   in which the drive device is electrically operated,
   characterized in that the drive device is designed in such a way that in the de-energized state it moves the tensile stress element (8, 10; 8, 10'; 8, 10") into the neutral position and/or holds the tensile stress element (8, 10; 8, 10'; 8, 10") in the neutral position.
8. Apparatus according to at least one of claims 1 to 7,
   characterized in that the drive device comprises a torque-controlled rotary drive (12) that is adjustable to a substantially constant torque.
9. Apparatus according to claim 8,
   characterized in that the rotary drive comprises a torque motor (12).
10. Apparatus according to claim 8 or 9,
    in which the tensile stress element (8, 10; 8, 10'; 8, 10") is pivotably mounted,
    characterized in that the tensile stress element (8, 10; 8, 10'; 8, 10") is pivotable by the rotary drive (12).
11. Apparatus according to claims 9 and 20,
    characterized in that the axis of rotation of the torque motor (12) is substantially flush with the swivelling axis of the tensile stress element (8, 10; 8, 10'; 8, 10").
12. Apparatus according to at least one of claims 8 to 11,
    in which the tensile stress element (8, 10; 8, 10'; 8, 10") comprises a rotatable compensating roller (8) and a pivotable extension arm (10; 10'; 10"), of which one end is pivotably mounted and the other, free end (10a) carries the compensating roller (8),
    characterized in that the rotary drive (12) exerts a torque on the extension arm (10; 10'; 10").
13. Apparatus according to claims 11 and 12,
    characterized in that the extension arm (10; 10'; 10") is fastened by its one end to the output shaft (12a) of the torque motor (12) and extends at an angle, preferably at right angles, to the axis of rotation of the output shaft of the torque motor (12).
14. Apparatus according to at least one of claims 1 to 13,
    in which the processing device (14) comprises a breaker (22; 22'), which is provided with a breaker edge (22a; 22a') for contacting engagement with the material (1) to be drawn thereover,
    characterized in that the breaker (22; 22') is disposed, viewed in conveying direction (A or A') of the material (1), upstream or downstream of the tensile stress element (8, 10; 8, 10').
15. Apparatus according to claim 14,
    characterized in that the engagement of the breaker (22; 22') is controllable in dependence upon the position of the tensile stress element (8, 10; 8, 10').
16. Apparatus according to claim 5 as well as according to claim 14 or 15,
    characterized in that the tensile stress element (8, 10; 8, 10') is movable into a neutral position, in which the material (1) is disengaged from the breaker (22; 22').
17. Apparatus according to at least one of claims 14 to 16, in which the breaker (22) is rotatably mounted,
    characterized in that the rotary position of the breaker (22) is controllable in dependence upon the swivel position of the tensile stress element (8, 10).
18. Apparatus according to claim 17,
    characterized in that the axis of rotation of the breaker (22) is substantially flush with the swivelling axis of the tensile stress element (8, 10).
19. Apparatus according to claim 18,
    characterized in that the axis of rotation of the breaker (22) is substantially flush with the breaker edge (22a).
20. Apparatus according to at least one of claims 17 to 19,
    characterized in that the breaker (22) is fastened in a rotationally fixed manner on the tensile stress element (8, 10).
21. Apparatus according to claims 12 and 20,
    characterized in that the breaker (22) is fastened in a rotationally fixed manner on the extension arm (10), preferably on one end thereof.
22. Apparatus according to one of claims 14 to 16,
    characterized in that the breaker (22') is disposed separately from the movable tensile stress element (8, 10') and in a stationary manner relative to the apparatus.
23. Apparatus according to at least one of claims 1 to 22,
    characterized by a position measuring device for detecting the swivel position of the tensile stress element (8, 10; 8, 10'; 8, 10") and a calibrating device (20), which upon activation of the apparatus, for calibrating the position measuring device, swivels the tensile stress element (8, 10; 8, 10'; 8, 10") into a neutral position and into a fully deflected swivel position.
24. Method of regulating the tensile stress in a band- or strip-shaped material (1) to be conveyed, in particular wrapping material or covering paper for rod-shaped articles of the tobacco-processing industry, in particular using the apparatus according to at least one of the preceding claims, whereby the material (1) is conveyed through at least two drawing roller pairs (4, 16) and loaded at an angle to its conveying direction by a movable tensile stress element (8, 10; 8, 10'; 8, 10"), which is disposed between the two drawing roller pairs (4, 16), in order to be deflected from its path of motion for the purposes of generating a tensile stress, wherein the tensile stress is regulated,
    characterized in that a force exerted on the tensile stress element (8, 10; 8, 10'; 8, 10") is adjusted to a substantially constant value independently of the position of the tensile stress element (8, 10; 8, 10'; 8, 10"), the force exerted on the tensile stress element (8, 10; 8, 10'; 8, 10") and the position of the tensile stress element (8, 10; 8, 10'; 8, 10") are each regulated independently of one another to a preset value and the difference of the conveying speed of the two drawing roller pairs (4, 16) is regulated to a value that is dependent upon the position of the tensile stress element (8, 10; 8, 10'; 8, 10").

Images