Abstract:
The invention relates to a process and an apparatus for producing packs, in particular cigarette packs. A change in the type of pack makes it necessary for the operators carefully to provide the correct packaging material assigned to the new type of pack. In practice, this change of material often takes place incorrectly. The invention avoid errors when the type of pack is changed in that markings, which are assigned to packaging material of different designs and are provided on the packaging material and/or the carrier thereof, in particular on a core of the reel, and/or the pack, are used to identify the packaging material and to check it for correct assignment in relation to the type of pack which is to be produced.

Description:
BACKGROUND OF THE INVENTION 
     The invention relates to a process for producing packs, in particular cigarette packs, using, for the purpose of wrapping pack contents, packaging material, namely prefabricated blank, material webs wound as a reel and/or blanks severed from said material webs. The invention also relates to an apparatus for carrying out the process. 
     In packaging technology, in particular during the production of cigarette packs, it is often required to produce different types of pack one after the other on the same packaging machine. The differences here may mean different text, designs or else contents, that is to say different cigarettes in particular. The change in the type of pack makes it necessary for the operators carefully to provide the correct packaging material assigned to the new type of pack. 
     SUMMARY OF THE INVENTION 
     The object of the invention is to facilitate and, in particular, render more reliable, the operation of changing a type of pack of a packaging machine, in particular for producing cigarette packs, so as to avoid the use of incorrect packaging material. 
     In order to achieve this object, the process according to the invention is characterized in that, when a packaging machine is started up or when the type of pack which is to be produced is changed, or when the packaging material (reel) is changed, markings, which are assigned to packaging material of different designs and are provided on the packaging material and/or the carrier thereof, in particular on a core of the reel, and/or the pack, are used to identify the packaging material and to check it for correct assignment in relation to the type of pack which is to be produced. 
     Accordingly, the invention automatically ensures that after a change the correct packaging material is used and the correct pack contents are packed. The markings on the packaging material or on the cigarettes may be formed specifically for identification with the aid of optoelectronic monitoring elements. Alternatively, it may be the standard design of the pack or of the cigarettes which is concerned, it being the case that, for the respective type of pack, characteristic external features, for example the brand mark, are used for identification. 
     The apparatus according to the invention is provided at suitable locations, namely in the region of conveying paths for packaging material, on the one hand, and in the region of conveying paths for cigarettes or cigarette groups, on the other hand, with optoelectronic sensing elements which sense, for example, from above the articles moved past them and which record characteristic features or markings for identification. The signals received are fed to an evaluation unit and, in the region of the latter, compared with stored, correct features. When incorrect packaging material or incorrect contents are detected, an appropriate signal is generated. 
     All recognition data for each type of pack and cigarette are stored in the control system and are compared continually or whenever necessary (change of brand) with the materials being run on the machine. The control system does not issue an enabling signal until all data are completely consistent. These recognition data vary according to the type of pack and cigarette and can be switched by the operator at the touch of a button or transmitted from a central control system to the control system of the respective packaging machine. 
     The packaging material, for example a material web wound to form a reel, can in the simplest case be identified by the application of, for instance, a dot-like marking of a different geometric form and/or color. The markings can also be applied with the help of labels. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Further details of the invention are explained in more detail below with reference to exemplary embodiments illustrated in the drawings, in which: 
     FIG. 1 shows a side view of part of a packaging machine with a blank magazine and CCD camera; 
     FIG. 2 shows a cross-sectional view of a reel with packaging material and a laser scanner; 
     FIG. 3 shows an arrangement according to FIG. 2 in a section taken along section line III/IV—III/IV; 
     FIG. 4 shows a further arrangement according to FIG. 2 in a section taken along section line III/IV—III/IV; 
     FIG. 5 shows a further part of a packaging machine with cigarette block and CCD camera; and 
     FIG. 6 shows an arrangement according to FIG. 5 in a section taken along section line VI—VI. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 shows part of a packaging machine for producing cigarette packs. This part is involved in the removing and feeding of blanks  10  from a blank magazine  11 . Said blank magazine  11  has two side walls  12 ,  13 , which guide the blanks and prevent said blanks  10  from sliding away laterally. 
     A removal element designed as a transfer roller  14  removes in each case one blank  10  from the bottom of the blank magazine  11 . The blank is held on a peripheral surface of the circular transfer roller  14  by suction bores (not shown) so that the blank lies on the peripheral surface of the transfer roller  14  as the latter is moved in the direction of arrow  16 . The removed blank  10  is transferred to a blank path  15 . 
     The blank  10  is positioned on the removal element, namely on the transfer roller  14 , in such a way that a side of the blank provided with markings is assigned to a scanning element, namely in the present case to a CCD camera  24 . This is positioned so that a lens  25  of the CCD camera  24  is aimed at the arched blank  10 . The blank  10  is usually positioned on the transfer roller  14  in such a way that the printed, i.e. outer, side of the blank is on the outside, i.e. facing the CCD camera. 
     The apparatus can be so arranged that only the first blank  10  taken from the blanks magazine  11  is sensed or scanned by the CCD camera  24 . But the apparatus can also be operated in that every blank  10  is checked by the camera  24 . In this case, in particular characteristic features of the blank  10  suitable for identifying the material are scanned. As an alternative, the blank  10  can be provided with markings which are applied for the explicit and exclusive purpose of identifying the material and which are scanned by the camera  24 . 
     The camera  24  is linked by means of a cable  26  to the central evaluation unit, in which the scanned markings are evaluated or a recorded image is compared to a stored, correct calibration image. 
     FIG. 2, FIG.  3  and FIG. 4 present examples for checking wound (packaging) material, i.e. reels. These can serve to manufacture an inner wrapping of the pack contents (inner liner) in the packaging of cigarettes or as an outer wrapping. In the first case, the material web comprise tin foil or paper, if necessary also a plastic film. Regenerated cellulose film or plastic film is generally used for the outer wrapping. 
     FIG. 2 shows a cross section through a corresponding reel  27 . In the case of this reel  27 , the packaging material is wound around a reel core  28 . Said reel core  28  is seated on a stub  29 , which bears the reel  27 . 
     The reel  27  is pushed onto the stub  29  to such an extent that it comes into contact with a stop disc  30 . The stop disc  30  has openings  31 . Through these openings  31 , an optoelectronic scanning means, designed for example as a laser scanner  32 , can view the end surface  34  of the reel. For this purpose, a laser-light-emitting component, for example a laser diode  33 , is arranged on the laser scanner  32  such that the laser beam emitted can make contact, through the opening, with the end surface  34  of the reel. The laser scanner  32  picks up again the laser light reflected by the end surface  34  of the reel and converts it into a corresponding signal. A cable  35  passes on this signal from the laser scanner  32  to the evaluation unit (not illustrated). Finally, by way of the signal produced by the laser scanner  32 , the evaluation unit identifies the packaging material wound up on the reel  27 . 
     Furthermore, the evaluation unit checks whether the identified packaging material corresponds with the expected packaging material. In this way, the evaluation unit can establish whether the packaging machine has been charged with the correct packaging material. If the evaluation unit establishes an error, it gives out a corresponding error signal. Alternatively or additionally, it interrupts the production process, that is to say it brings the packaging machine to a standstill. 
     FIGS. 3 and 4 each show a reel  27  with a stop disc  30  in a section taken along section line III/IV—III/IV (FIG.  2 ). These stop discs  30  each have two openings  31 . These openings  31  are of such a magnitude that in each case just two spokes or connecting webs  36  are left. In addition, the openings  31  are of disc-shaped contour. Through the openings  31 , it is possible to see the layers, in each case of a material web  37  of packaging material, which are wound up onto the reel core  28 . The reel core  28  is seated—as in FIG.  2 —on the stub  29 . 
     FIG. 3 shows a bar code  38  provided on the reel core. In contrast to FIG. 3, in FIG. 4 the bar code  38  is provided on the layers of the material web  37  rather than on the reel core  28 . When the material web  37  is being unrolled from a reel  27 , the reel  27  rotates about the stub. In this case, the bar code  38 , which is provided on the reel  27 , also rotates. A laser scanner  32 , which is provided in front of the openings  31 , can then scan the rotating bar code  38  in order to produce a scanning signal for identifying the packaging material used. 
     The arrangement of a laser scanner  32  installed in a stationary manner and of the bar code  38  rotating away beneath the same allows the laser scanner to read the entire bar code  38  without difficulty. 
     The stop disc  30  preferably rotates with the reel  27 . This has the advantage that there is no friction between the stop disc  30  and packaging material wound up on the reel  27 . In this case, at least two bar codes are applied to the reel  27 , namely either on the reel core  28  and/or on the packaging material wound up on the reel  27 . This is because it is possible for at least one bar code  38  to be concealed at least partially behind a connecting web  36 . In this case, correct scanning of the bar code  38  would no longer be ensured. As a result, a number of the same bar codes  38  have to be provided. A second bar code  38  thus has to be spaced apart from a first bar code  38  by a distance which corresponds at least to the width of the connecting web  36 . Moreover, the longitudinal extent of the bar code  38  is not any larger than the opening  31 . As a result, at least two bar codes  38  are arranged such that at least one can be seen in its entirety in an opening  31 , even if the second bar code  38  is concealed by a connecting web  36 . 
     In the case of an alternative configuration, it is merely the reel  27  which rotates, while the stop disc  30  is at a standstill. In this case, one bar code per reel is sufficient. However, the laser scanner  32  has to be arranged such that it views the (stationary) opening  31 . In the case of this variant, it is nevertheless necessary to ensure that excessive friction does not occur between the stop disc  30  and packaging material or the lateral edges of the material web  37 , in order to avoid damage to the packaging material. 
     The bar code  38  applied to the material web  37  is preferably applied directly onto the layers of the material web  37  by means of an ink-jet printer. Accordingly, it is also possible for the bar code  38  to be applied to the reel core  28  by means of ink-jet printing. However, the practice of applying adhesive labels with bar codes  38  is also suitable specifically for the reel core  28 . 
     FIG. 5 shows a cigarette block  39  with three layers of cigarettes. As the production process continues, said cigarette block  39  is introduced into a pack formed by the packaging machine. In order to ensure that cigarette blocks  39  which are to be introduced belong to the type of pack which is to be produced, the cigarette block  39  is checked as well. A further optoelectronic sensing element, namely a further CCD camera  40 , is provided for this purpose. Said CCD camera  40  senses markings on the cigarette itself, for example the printed-on cigarette brand, rings on the filter or in the vicinity of a cigarette end or other text or printing on the cigarettes. In this case, the CCD camera is arranged such that it can sense an entire layer of a cigarette block  39 . 
     In the production process, a carry-along element  43  which is driven by a chain conveyor  41  conveys a cigarette block  39  in the direction of the arrow  42 . The cigarette block  39  is guided by a bottom guide  44  beneath the cigarette block  39  and by a top guide  45  above the cigarette block  39 . The top guide  45  is interrupted in the region of the CCD camera  40  and has an opening  46  there. Through this opening  46 , the CCD camera  40  can view the cigarette block  39 , namely the top layer thereof. As a cigarette block  39  is pushed through the bottom guide  44  and the top guide  45 , the CCD camera  40  can sense the markings provided on the top layer of the cigarette block  39  and convert them into a corresponding signal. This signal is routed to the evaluation unit via a connection, for example a cable  47 . The evaluation unit assigns the sensed signal to a certain type of cigarette and in this way can identify the cigarettes or the type of cigarette. The evaluation unit also checks whether the identified type of cigarette corresponds to the type of pack which is to be produced, that is to say whether the assignment of the cigarette in relation to the type of pack which is to be produced is correct. 
     FIG. 6 shows the arrangement from FIG. 5 in a section taken along section line VI—VI. Since in each case two cigarette blocks  39  are processed here at the same time, two carry-along elements are provided, or a double-size carrying-along element  43 , which is driven by two chain conveyors  41 , is provided. It is also possible to see two openings  48 ,  49  in the bottom guide  44 , through which the carry-along element  43  projects. In this case, the top guide is of such a width that it covers over the two cigarette blocks  39  completely. However, the top guide  44 , just as in FIG. 5, has an opening  46 , so that FIG. 6 shows that edge of the top guide  45  which is formed by the opening  46 . Through the opening  46 , the lenses  50 ,  51  of the CCD camera  40  can view the cigarette blocks  39  guided through beneath them. 
     Additionally or alternatively, it is also possible for the opening to be provided in the bottom guide. In this case, the CCD cameras are provided beneath the bottom guide, the lenses being oriented upward. However, it is also possible for one or more CCD cameras to be arranged alongside the top and bottom guides. 
     The signals produced by the optoelectronic sensing elements or scanning means, namely the CCD camera  24 ,  40  or the laser scanner  32 , are fed—as explained—to the evaluation unit. The evaluation unit uses these signals to identify the packaging materials or the pack contents, namely cigarettes, and checks whether the packaging materials used and/or the cigarettes correspond to the type of pack which is to be produced. Identification takes place, for example, by a signal comparison with reference signals. 
     In addition to, or instead of, such a comparison of a received signal with a stored signal, it is also possible for the received signal to be fed to a filter, for example a so-called matched filter, which is matched to the expected signal. Then, by way of the starting signal of the matched filter, a threshold decision element provides the decision as to whether the received signal corresponds to the expected signal and thus to the expected packaging material or contents. 
     However, it is also possible to use other signal-processing methods for identifying the packaging material or the type of cigarette. 
     The operation of identifying and checking packaging material and cigarettes takes place, in particular, when a packaging machine has run empty and has been newly started up. At the beginning of a new production cycle, at least the first cigarette blocks and packaging units, for example blanks, are checked. Preferably the first five cigarette blocks, or five pairs of cigarette blocks, and the first five, or five pairs of blocks, and the corresponding packs, with the result that, after this number, the sensing elements, namely CCO cameras and laser scanner, and the evaluation unit can be switched off. In the case of one variant, however, the system formed in this way continues throughout the entire production process. 
     The process according to the invention and the corresponding apparatus ensure that incorrect material is detected straight away. This makes it possible to avoid errors caused by human error, that is to say loading the packaging machine with incorrect packaging material or incorrect cigarettes. It is thus also possible, without difficulty, for a packaging machine which uses the process according to the invention, and an apparatus according to the invention, to be operated by operators who have been acquainted with it for only a short period of time and/or without lengthy training procedures being required.