EP0648177B1 - Process and device for supplying a packaging machine with packaging material - Google Patents

Abstract

A process and device are disclosed for supplying a packaging machine, in particular a candy packaging machine, with packaging material. A strip (1) of packaging material is drawn from a supply reel (2) by a pair of drawing cylinders (4, 4') and is cut by a cutting device (8, 9) into sections of packaging material having a predetermined length. During each working cycle of the machine, a section of packaging material is supplied to a wrapping station and the pre-adjustable length of the sections of packaging material is regulated by a regulating circuit (20) which includes the drive of the pair of drawing cylinders. The speed of rotation of a shaft (8) that bears a rotating knife of the cutting device and the speed of rotation of the driven drawing cylinders (4, 4') of the pair of drawing cylinders are continuously determined during each working cycle of the packaging machine. The value of the speed of rotation for the drawing cylinders is calculated taking into account the circumference of the drawing cylinders as well as the desired length of the sections of packaging material and is immediately set by means of a highly dynamic drive (9) linked to a control device.

Description

The invention relates to a method for supplying packaging material to a packaging machine, in particular a candy packaging machine, wherein at least one packaging material strip is drawn off from at least one tape supply reel by a pair of take-off rolls and separated into a predetermined pull-off length by a cutting device and one packaging material section is fed to a wrapping station per machine cycle for packaging a package , in particular sweets, the preselectable withdrawal length of the packaging section being regulated by a control circuit containing the drive of the pair of withdrawal rollers. The invention further relates to a device for supplying packaging material to a packaging machine, in particular for carrying out the aforementioned method.

From DE-A-32 15 444 a device for correcting rules of a packaging material tape provided with printing marks is known. The packaging tape is conveyed by a pair of rollers. The pair of rollers is driven by a change gear, a differential being arranged between the change gear and the pair of rollers, the speed of which is superimposed on the change gear. The differential is driven by a DC motor. The position of the print mark at the setpoint is detected by means of an optoelectronic scanning head in connection with pulse generators on the single-turn shaft of the machine. If the position of the print marks deviates from the target value, the speed of the take-off rollers is increased or decreased by an electronic controller via the direct current motor and the differential gear until the position of the print marks matches the target value. If, due to the format change in the wrapping process, a different length of the packaging section is required, the corresponding change gears in the change gear transmission must be replaced.

The mechanical effort and the time required to change the format are therefore very high. This device also does not meet the requirements of the modern packaging industry with regard to print centering and length of packaging section. In addition, for the interruption of the packaging supply in the absence of packaged goods (pack pieces) Separate devices are mainly required at the wrapping station. Since this problem is very complicated, a large number of solutions are known for this, in which one of the take-off rollers is pivoted away and placed on the packaging material belt again in order to continue the removal of the packaging material. The pivoting movement of the take-off roller takes place predominantly by means of cams and ratchet mechanisms.

DE-A-39 36 869 describes a device for interrupting the supply of packaging material, which consists of two cam disks which are offset by 180 ° on one axis and to which levers and control elements are assigned which cause a take-off roller to pivot when no packaged goods ( Package) is present at the wrapping station and therefore no section of packaging may be fed. However, these devices soon reach their performance limits. In the case of high-performance packaging machines, there are often malfunctions in the packaging supply. This means that the packaging tape cannot continue to run after the take-off rollers have been lifted due to inertia. This leads to the formation of snippets and thus to faults in the packaging process. In order to reduce the risk of snipping, the time for lifting and putting on the take-off roller was chosen so that the last packaging section before lifting and the first section after putting on the pull-off roller are shortened, which, however, in turn leads to a reduction in the quality of the packs and leads to increased packaging consumption. The increased consumption of packaging material results from the fact that an excessive overlap of the packaging material ends on the packaged goods must be selected in order to achieve a sufficient wrapping of the goods in the case of shortened sections of packaging material, which would, however, not be necessary if the packaging machine were to run continuously.

These problems also occur each time the packaging machine is stopped and restarted. It is difficult for an exact setting that at least one of the two take-off rollers is usually provided with an elastic covering.

From DE-A-31 14 470 a device for cutting sheets from a web is known, which is drawn off from a supply roll by means of intermittently driven take-off rollers by a stepping motor becomes. The sections which are advanced in steps are separated by a cross-cutting device which carries out a pivoting movement and is likewise driven by a stepping motor. Means for further transport of the sections are also provided.

However, this device is only suitable for packaging machines with a low number of cycles. This device is not suitable for direct, practically continuous removal of packaging materials in the high-performance range of 1,000 and more cycles per minute, since the dynamics required for synchronization would not be achieved with idle cycle, start-up and tours. For example, with a machine cycle count of 1,000 cycles and a section length of 75 mm during synchronization after an idle cycle, load acceleration torques of 5 to 6 Nm occur. So that the stepper motor does not fall out of step and "loses" steps, the start frequency for acceleration in start-stop operation must be reduced to approximately 2 kHz. However, about 12 kHz would be required to synchronize and achieve the required dynamics. The moment for the acceleration of the packaging supply spools was not taken into account.

In DE-A-31 14 470 this drive load was circumvented by a floating supply loop while accepting the known disadvantages of the course of the web due to the undefined starting position and the static charge, especially in the case of films.

Further methods and devices for controlling the provision of packaging material on a packaging machine are known from GB-A-22 13 456 and GB-A-22 04 717. Here, however, the cutting of the packaging sections is controlled by controlling a knife speed or by interrupting the knife drive.

The invention is therefore based on the object of improving a method of the type mentioned in such a way that the wrapping station of a continuously operating packaging machine of high packaging performance always has sections of a predetermined, freely selectable length at the right time and in the correct length, taking into account different conditions in the packaging process and non-stationary States of the packaging machine are supplied so that malfunctions as well as losses of packaging material can be avoided in an uncomplicated manner.

The invention is also based on the object of providing a device for supplying packaging material on a continuously operating packaging machine, in particular a candy packaging machine, specify by which the changing requirements of the packaging process can be taken into account in an advantageous and technically simple manner.

The aforementioned object is achieved according to the invention in a method of the type mentioned at the outset in that increments of a rotational speed of a knife shaft of a rotating knife of the cutting device and a rotational speed of at least one take-off roller of the pair of take-off rollers are determined in succession within each machine cycle and are related to one another and taking into account the scope the take-off roller of the preselected take-off length and the speed ratio of the knife shaft and the take-off roller calculate a speed value for the take-off roller corresponding to this take-off length and a drive of the take-off roller is activated in the next machine cycle to achieve this calculated speed value.

The method according to the invention achieves a highly flexible procedure which, with short reaction times, does justice to changes in the packaging process and also optimally takes into account non-stationary operating states of the packaging machine, such as the start-up process or a change in the packaging task. The desired pull-off length can preferably be preselected in millimeters using a digital selector switch, with the actual pull-off length constantly being as close as possible to the target value selected at the selector switch while continuously monitoring the increments of the speed of the rotating knife and the speed of the pair of pull-off rollers within one machine cycle, including the diameter of the pair of pull-off rollers and the corresponding value for the drive speed of the draw-off rollers is realized without interrupting the machine run by driving the draw-off rollers, so that changes in the draw-off length take effect in the next subsequent machine cycle. A machine cycle is the time between two subsequent cutting operations of the rotating knife, in which it rotates 360 °.

The speed of the take-off rollers corresponding to the selected take-off length, in particular the directly driven draw-off roller, is determined after the inventive determination of the target speed for the driven take-off roller of the pair of draw-off roller pairs when choosing a larger take-off length increased within one machine cycle or decreased within one machine cycle if a shorter trigger length was selected. Since the diameter of the take-off rollers, in particular the driven take-off roller, is included in the target speed determination, the conveying speed of the packaging material belt is increased or decreased within a work cycle, depending on the peripheral speed of the removal rollers, until the predetermined withdrawal length for the packaging material section is reached.

In this way, it is also possible for the operating personnel of the associated packaging machine in a simple manner to always choose the length of the packaging sections in accordance with the objectively most favorable section length during format changes or also during the wrapping process for a specific format of the packaged goods or the packages. This leads to considerable savings in packaging materials, in particular when the packaging material is not provided with printing marks. In addition, there is no mechanical effort, such as e.g. intervention in a drive gear is necessary.

According to an advantageous embodiment of the invention, when it is determined that there is no packaged goods or packages at the wrapping station and therefore no packaging section is to be fed, the driven take-off roller begins for a certain period of time, starting with the cut-off of the previous packaging section driven in the opposite direction (negative speed value), so that the packaging tape is retracted, the retraction path being sensed incrementally and then, even within the same machine cycle, the take-off rollers are stopped (speed 0). As a result of this, due to the inertia of the packaging material take-off, including the take-off rollers, the previous packaging material strip is withdrawn from the area of the cutting device and brought into a defined starting position behind the knife edge of the rotating knife before the next machine cycle starts.

According to a further advantageous embodiment of the method according to the invention, it is alternatively also possible, in connection with the retraction of the packaging tape, by driving the pair of take-off rollers contrary to the normal direction of rotation, the retracted length of packaging, ie the amount of retraction of the packaging tape behind a cutting edge of the rotating knife of the cutting device, to be recorded incrementally, stored and added to the withdrawal length of the next section of packaging.

According to yet another preferred embodiment of the invention, in the event of an interruption in the packaging process and thus an interruption in the supply of the packaging tape, which, due to the inertia of the take-off device elements, including the take-off rollers, leads to an inevitable re-running of the packaging tape, it is preferred to carry out this caster to determine incremental recording on the take-off roller, preferably the driven take-off roller, to compare this value with the increment on the take-off roller at the time of the previous cut of the packaging material and to bring it back into a defined starting position behind the knife edge within the same machine cycle by withdrawing the packaging tape in the next machine cycle, a section of packaging with the specified pull-off length is cut off.

In the event that no packaged goods or detected packages are available at the wrapping station in several successive cycles, the drive of the pair of take-off rollers is kept in the shutdown state (zero speed) for the corresponding period of time.

According to yet another preferred embodiment of the invention, the drive speed of the pair of take-off rollers, ie during a non-stationary start-up process of the packaging machine, ie during a start-up machine cycle to achieve synchronization and for rapid acceleration to achieve the steady-state operating state within the start-up machine cycle the driven take-off roller, briefly increased above a setpoint speed corresponding to the predetermined take-off length for the take-off rollers, in order to ensure that the predetermined take-off length of the packaging section is reached even during the start-up machine cycle.

According to yet another preferred embodiment of the invention The method, the position of a print image on the pressure medium tape, in particular with the intermediation of lateral pressure markings, is sensed and the drive speed of the pair of draw rollers corresponding to a centered target position of the print image based on the deduction length of a packaging section changes.

The above object is achieved with regard to a device for supplying packaging material to a packaging machine, in particular a candy packaging machine, with at least one tape supply spool for a packaging material tape, a pair of take-off rollers for the packaging material tape, a cutting device downstream of the pair of take-off roller pairs, a wrapping station downstream of the cutting device, and an adjusting device for a take-off length from the cutting device leaving the packaging device sections and a sensor signal-receiving control device connected to a drive of the pulling roller pair, preferably for carrying out the aforementioned method, according to the invention solved in that a highly dynamic drive motor, connected to the control device, acts directly on a driven pulling roller of the pulling roller pair has a rotating knife, detection devices are provided for the rotational speed of the rotating knife and a knife shaft e of the rotating knife is assigned at least one sensor for detecting a cutting time.

In this way, an advantageous device for the supply of packaging sections to the wrapping point is specified with a relatively uncomplicated structure, which makes it possible to make changes to the desired trigger length immediately and without modifications without further ado and without interrupting the machine operation.

The highly dynamic drive motor is preferably a servo motor coupled directly to a shaft of the driven take-off roller and corresponds to the speed of the knife shaft of the rotating knife to the machine speed of the packaging machine, with an additional incremental speed sensor being assigned to the knife shaft.

In this way, a change in the length of the packaging section in each phase of the packaging process and during the run Packaging machine without interruption to work is also possible, as is continuous monitoring of the packaging cut with unchanged setpoint specification. The device according to the invention also makes it possible in a simple manner to implement empty cycles in the absence of packaged goods, correct print image centering and accelerated start-up processes for a start-up machine cycle in an advantageous manner and with a high response characteristic.

Further preferred embodiments of the subject matter of the invention are set out in the remaining subclaims.

Fig. 1

eine Verpackungsmaschine mit einer Vorrichtung zur Packmittelzuführung nach einem Ausführungsbeispiel der Erfindung in schematischer, perspektivischer Vorderansicht,

Fig. 2

ein Blockdiagramm einer Steuerung der Zuführung von Packmittelabschnitten zum Packgut der Vorrichtung nach Fig. 1,

Fig. 3

ein Drehzahl- bzw. Drehgeschwindigkeits-/Zeit-Diagramm für die Packmittelzuführung bei Unterbrechung und Wiederanlauf des Verpackungsvorganges.

The invention is explained in more detail below using an exemplary embodiment and associated drawings. In these show:

Fig. 1

1 shows a packaging machine with a device for supplying packaging material according to an embodiment of the invention in a schematic, perspective front view,

Fig. 2

2 shows a block diagram of a control of the supply of packaging material sections to the packaged goods of the device according to FIG. 1,

Fig. 3

a speed or speed / time diagram for the packaging supply when the packaging process is interrupted and restarted.

In Fig. 1, a device for supplying packaging on a candy packaging machine is shown schematically. A packaging tape 1 is guided from a tape supply reel 2 over deflection rollers 3 and drawn off from take-off rollers 4, 4 'of a pair of take-off rollers and transported further in a substantially vertical direction. Preferably, the packaging tape removed from the tape supply reel 1 is provided with pressure markings 5 for centering a printed image. An inner strip 7, which is processed together with the packaging material strip 1, is fed to the take-off rollers 4, 4 ′ from a second strip supply spool 6.

It is also possible to use the tape supply reel 6 as a further packaging tape for a change of packaging material, which is an alternative to that Packaging tape 1 can be fed from the tape supply reel 2. A rotating knife shaft 8, which carries a rotating knife 9, which cooperates with a stationary knife 10, is arranged below the pair of pull-off rolls with the pull-off rolls 4, 4 '. The rotating knife 9 and the stationary knife 10 form a cutting device for the packaging tape 1 and the inner strip 7, which are fed together vertically to the cutting device by the take-off rollers 4, 4 '. Below the cutting device with the knives 9, 10 there is a rotating gripper wheel 11 of a wrapping station, which interacts with a separating plate 12. The gripper wheel 11 has pairs of holding arms 16, with a candy B being subsequently picked up by the separating plate 12 by each holding arm pair 16 and being transported into a position in which a packaging section 17 is seen from above by the cutting device 8, 9, 10 straight to be packed candy B is performed, as shown schematically in Fig. 1.

An incremental encoder 13 is assigned to the knife shaft 8 of the rotating knife 9, which rotates synchronously with the machine speed. Furthermore, a sensor 14 for detecting the respective cutting time is installed below the knife arrangement 9, 10. The packaging tape 1 has print markings 5 along a side edge, which correlate with the position of a corresponding print image, not shown here, and a print mark scanning device 15, which corresponds to a print image sensor, is provided between the deflection rollers 3, whereby the print markings 5 are detected in relation to the trigger length, ie the length of a packaging section 17 separated from the packaging tape 1 by the rotating knife 9, the centering of the printed image on the packaging section 17 can be achieved.

As part of the wrapping station, a sensor 18 for monitoring the presence of a candy B between a relevant pair of holding arms 16 is assigned to the holding arms 16 of the gripper wheel 11 in the area between a receptacle of the sweets B by the separating plate 12 and the feeding of the packaging sections 17.

Immediately with the drive shaft of the driven take-off roller 4 ' a servo motor 19 is connected as a highly dynamic drive, in which a further sensor, not shown here, is arranged as an incremental encoder.

Furthermore, a programmable control device 20 is provided, with which the transmitter and sensor elements 13, 14, 15, 18 and the incremental sensor of the servo motor 19 for transmitting the detected actual values to the control device 20 are connected, and in which the corresponding adjustment is carried out the corresponding setpoints, which in turn are at least partially variable, in particular in connection with a trigger length for the packaging section 17, which can be predetermined manually by means of a digital selector switch (not shown). The control device 20 drives the drive or servo motor 19 and thus the driven one Draw-off roller 4 'of the pair of draw-off rollers 4, 4' is controlled in such a way that the desired values are reached.

The control sequence for the control of the packaging material supply, i.e. the feeding of packaging sections 17 to the candies B held by the holding arms 16 on the gripper wheel 11 is shown in FIG. 2.

In stationary operation, the candy packaging machine runs in the high-performance range with a cycle number of 1,000 to 1,500 revolutions or cycles per minute, this cycle number being equal to the number of separating operations carried out by the rotating knife 9 for separating the packaging sections 17. During each machine cycle (also referred to here as cycle), a packaging section 17 is cut off and also a completely wrapped candy is released from the machine, the wrapping process on the gripper wheel 11 itself extending over several cycles, so that several sweets per machine cycle in different phases of the wrapping and packaging by the respective packaging sections 17 are. A machine cycle begins with a cutting process by the rotating knife 9 and the separation of a packaging section 17 and ends with the cutting process for the next packaging section 17 after a 360 ° rotation of the rotating knife 9.

As shown in the flowchart according to FIG. 2, when the packaging machine is switched on (start), the actual states of the packaging machine are namely the machine speed represented by the speed of the knife shaft 8 by the incremental encoder 13, the speed of the driven take-off roller 4 'by the incremental encoder installed in the servo motor 19 and the selector switch on the control panel 21 in connection with the control device 20 by a digital, calibrated in millimeter division for the trigger length of the packaging section 17 set trigger length queried by the control device 20.

In addition, depending on the signal from the sensor 18, it is determined whether a package, ie a candy B, is present on the gripper wheel 11 or whether it is an empty cycle (no candy detected), and the position of a pressure marking 5 is determined by the pressure marking Scanning device 15 (optical head) and by the sensor 14 detects the position of the rotating knife 9. From the aforementioned signal values, which are compared every ms, the necessary movement function of the servo motor 19 is calculated by the control device 20, and the servo motor 19 and thus the speed and direction of rotation of the driven take-off roller 4 'of the pair of take-off rollers 4, 4' are correspondingly determined via a power controller 22 influenced.
The following special features apply to the individual operating states:

• t₀ = Beginn Leertakt
• t₁ = Beginn Folgetakt
• t₂ = Beginn 2. Folgetakt (Normalbetrieb)
• V_Soll = Vorgegebene Abzugsgeschwindigkeit
• +V₂ = max. Antriebsgeschwindigkeit
• -V₁ = max. Rückdrehgeschwindigkeit

In the event that it is determined by the sensor 18 that there is no candy B between the relevant holding arm pair 16 and thus no packaged goods (package) are present and an empty cycle is indicated, the information "j", ie " Empty clock available "output. Accordingly, the power controller 22 is acted upon in accordance with the sequence provided in the program of the control device 20 and the servo motor 19 is braked to zero speed, the direction of rotation is reversed and the servo motor 19 is then stopped, the return path being recorded incrementally. The retracted length of the packaging tape 1 is opened to the next deduction length for the next packaging section 17. Alternatively, it is also possible to incrementally record the length of packaging that has preceded due to inertia after the preceding packaging section 17 has been cut off and the packaging tape, ie the front edge thereof, before the next one Bring the cut into a defined starting position behind the knife edge. The control course and the resulting movement of the servo motor 19 and thus the take-off rollers 4, 4 'including the subsequent restart of the packaging machine for the separation of the next packaging section 17 can be seen from the curve diagram in FIG. 3. Here mean:

• t ₀ = start of empty cycle
• t ₁ = start of next cycle
• t ₂ = start of 2nd cycle (normal operation)
• V _target = specified take-off speed
• + V ₂ = max. Drive speed
• -V ₁ = max. Reverse speed

This control sequence relating to the stopping and turning back of the servo motor 19 must be completed within one machine cycle. The next time sensor 14 is polled, sensor 18 is also polled again. If no candy B is present between the relevant holding arms 16 of the gripper wheel 11, the position "0", ie the drive (V ₀ ) which has been stopped, is maintained for the servo motor. If it is determined that a candy B is again present and a next packaging task is to be solved by supplying a packaging section 17, the "start" function is triggered and the acceleration of the servo motor 19 is regulated as between times t ₁ and t ₂ is shown in Fig. 3, so that within this, following the standstill of the servo motor 19, a synchronization with the specified trigger length is achieved. The lack of packaging length up to the knife edge, as can be seen from the area of the starting cycle between times t ₁ and t ₂ in FIG. 3, is achieved by briefly increasing the take-off speed and then returning it to the desired speed corresponding to the take-off length.

Within the method, it is also possible to exactly center the print image position on the packaging tape 1 in relation to the predetermined withdrawal length of the desired packaging sections 17, in particular with the aid of the lateral printing markings 5 and the printing marking sensor 15. A correction of the speed of the withdrawal rollers 4, 4 ' For servo image centering, the servo motor 19 is used to link the output signals of the print image capturing device or print marking scanning device (sensor) 15 and the sensor 14 which detects the cutting time. If both sensor signals have the value "1", the rotational speed for the servo motor 19 and thus for the driven take-off roller 4 'corrected to "plus". If the combination of the output signals results in the value "0", the control device 20 outputs a setpoint speed corrected for "minus" to the servo motor 19 via the power controller 22. This causes the print image on the packaging tape 1 to oscillate around an edge of the print marking 5 in the range of tenths of a millimeter. The position of the printed image on the ready-packed candy B can thus be fixed according to a specific specification by arranging the sensors 14 and 15, based on the time or machine cycle.

In the event that the trigger length for the packaging section 17 is to be changed, e.g. when switching to another packaged goods or. Candy size (format change) or if it is necessary for other reasons to change the pull-off length of the packaging section 17, then the desired pull-off length is adjusted via the millimeter-controlled and preferably digital selector switch (not shown here) on the control panel 21 of the packaging machine and thus into the control device 22 entered. By reading out the selector switch value, taking into account the scope of the driven take-off roller 4 'and taking into account the number of cycles by evaluating the incremental encoder 13 of the knife shaft 8, the new desired speed determining the take-off length for the driven take-off roller 4' or for the servo motor 19 by the control device 20 determined and corrected via the power controller 22.

The relationship is: $$\frac{\text{Number of bars x trigger length}}{\text{Scope of the take-off roller}}\text{= Speed}$$

When the trigger length is increased, the servo motor 19 connected to the trigger roller 4 'tracks the speed until the ratio of the increments detected by the incremental encoder 13 and the incremental encoder within the servo motor 19 corresponds to the calculated value. If the trigger length is shortened, the speed of the driven trigger roller 4 'is reduced accordingly. The required synchronization is achieved at short notice through very short comparison intervals and a high incremental resolution. This makes it possible to achieve any desired take-off length while the packaging machine is running and without interrupting the packaging process within one work cycle (machine cycle) and without mechanical modifications.

Claims (14)

1. Method for the supplying of packaging means to a wrapping machine, in particular sweets wrapping machine, wherein at least one packaging means band is drawn off from at least one band supply spool by a withdrawal roller pair and separated by a cutting equipment into packaging means portions of predetermined withdrawal length and one packaging means portion for each machine cycle is fed to a wrapping station for the wrapping of one packaging item, in particular sweets, wherein the presettable withdrawal length of the packaging means portion is regulated by a regulating loop containing the drive of the withdrawal roller pair, characterised thereby, that increments of a rotational speed of a blade shaft (8) of a rotating blade (9) of the cutting equipment as well as of a rotational speed of at least one withdrawal roller (4') of the withdrawal roller pair are ascertained successively within each machine cycle and set into relationship each to the other and, subject to consideration of the circumference of the withdrawal roller (4'), the preselected withdrawal length as well as the rotational speed ratio of the blade shaft (8) and the withdrawal roller (4'), a rotational speed value corresponding to this withdrawal length is computed for the the withdrawal roller (4') and a drive (19) of the withdrawal roller (4') is controlled for reaching this computed rotational speed value in the next following machine cycle.
2. Method according to claim 1, characterised thereby, that on ascertaining the absence of a packaging item (B) for one machine cycle and beginning with the instant of the severing of the preceding packaging means portion, the withdrawal roller (4') is driven in opposite sense of rotation with retraction of the packaging means band (1) and incremental detection of a retraction travel and subsequently stopped within the same machine cycle with the packaging means band (1) in a defined starting position with reference to a downstream cutting edge of the rotating blade (9).
3. Method according to claim 2, characterised thereby, that the amount of a retraction of the packaging means band (1) behind a cutting edge of the rotating blade (9) is detected incrementally, stored and added to the preset withdrawal length of the following packaging means portion.
4. Method according to claim 1, characterised thereby, that on an interruption of the feed of the packaging means band (1), a running-on of the packaging means band (1) is detected incrementally as actual value at the one, preferably driven withdrawal roller (4') of the withdrawal roller pair (4, 4') and compared with an incremental value of the withdrawal roller (4') at the instant of the severing of the preceding packaging means portion as target value in order, within the same machine cycle and by retraction of the packaging means band (1), to bring this into a defined starting position behind the blade edge so that a packaging means portion of the preset withdrawal length is severed in the next following machine cycle.
5. Method according to at least one of the preceding claims 1 to 4, characterised thereby, that during a running-up machine cycle, a drive rotational speed of the withdrawal roller pair (4, 4') is increased for a short time above a target rotational speed (v_soll), which corresponds to the preset withdrawal length, of the withdrawal rollers (4, 4').
6. Method according to at least one of the preceding claims 1 to 5, characterised thereby, that a printed image position is detected by sensor as actual value on the packaging means band (1) and the drive rotational speed of the withdrawal roller pair (4, 4') is varied in dependence on the centred target position of the printed image.
7. Device for the supplying of packaging means to a wrapping machine, in particular sweets wrapping machine, with at least one band supply spool for a packaging means band, a withdrawal roller pair, a cutting equipment downstream of the withdrawal roller pair, a wrapping station downstream of the cutting equipment and a setting equipment for a withdrawal length of packaging means portions bearing the cutting equipment as well as a control equipment picking up sensor signals and being connected with a drive of the withdrawal roller pair, in particular for the performance of the method according to claim 1, characterised thereby, that a highly dynamic drive motor (19), which is connected with the control equipment (20), engages directly at a driven withdrawal roller (4') of the withdrawal roller pair (4, 4'), the cutting equipment comprises a rotating blade, detecting equipments are provided for the rotational speed of the rotating blade (9) and of at least the driven withdrawal roller (4') of the withdrawal roller pair (4, 4') and at least one sensor (14) for the detection of an instant of cutting is associated with a blade shaft (8) of the rotating blade (9).
8. Device according to claim 7, characterised thereby, that the highly dynamic drive motor is a servo-motor (19) coupled directly with a shaft of the driven withdrawal roller (4').
9. Device according to claim 7 or 8, characterised thereby, that a rotational speed of the blade shaft (8) of the rotating blade (9) corresponds with the machine rotational speed of the packaging machine and an incremental rotational speed sensor 913) is associated with the blade shaft (8).
10. Device according to at least one of the preceding claims 7 to 9, characterised thereby, that the wrapping station comprises a gripper wheel (11) with retaining arms (16) for the withdrawal of packaging items, in particular of sweets (B), from a singling plate (12), wherein the gripper wheel (11) is associated with a sensor equipment (18), which monitors the seizing of a packaging item, in particular of sweets (B) by a retaining arm pair (16) on the path between withdrawal of the packaging item, in particular of sweets (B), by the retaining arm pair (16) and feeding of a packaging means portion.
11. Device according to at least one of the preceding claims 7 to 10, characterised thereby, that a substantially vertical guidance of the packaging means band (1) is provided between the withdrawal roller pair (4, 4') and the feeding of the packaging means portions to a packaging item, in particular a sweet (B), retained between a retaining arm pair (16).
12. Device according to claim 11, characterised thereby, that a deflecting roller pair (3) is connected upstream of the withdrawal roller pair (4, 4').
13. Device according to at least one of the preceding claims 7 to 12, characterised thereby, that a printed image position sensor (15), which is connected with the control equipment (20), is associated with the packaging means band (1).
14. Device according to at least one of the preceding claims 7 to 13, characterised thereby, that a first band supply spool (2) for the packaging means band (1) and a second band supply spool for an inner strip (7) are provided and the packaging means band (1) as well as the inner strip (7) are ledtogether through the withdrawal roller pair (4, 4') by way of deflecting rollers (3).

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