Patent Publication Number: US-10781006-B2

Title: Packaging machine for packaging with stretch film and optimized packaging method

Description:
CROSS-REFERENCE TO PRIOR APPLICATION 
     Priority is claimed to European Patent Application No. EP 18 179 617.8, filed on Jun. 25, 2018, the entire disclosure of which is hereby incorporated by reference herein. 
     FIELD 
     The invention relates to a packaging machine and a method for packaging products to be packaged by means of a stretchable film having a film transport device for the film feed to a product to be packaged, and having a first and second belt conveyor for transporting the film, each of which comprises a first and a second belt conveyor that are synchronously driven in a film transport direction specified by the film transport device and are arranged side by side, at least the second belt conveyor being movable in a direction perpendicular to the film transport direction, and with a movable film guiding element, by means of which the film can be introduced into the film transport device, the film guiding element comprising a guide plate for guiding the film that has a first and a second recess in an upper edge in the vertical direction toward the belt conveyors, the first belt conveyor being introducible into the first recess and the second belt conveyor into the second recess, thereby defining a first zero position with respect to the width of the film. 
     BACKGROUND 
     EP 3 093 244 B1 discloses such a packaging machine for packaging products to be packaged by means of films which are designed to transfer the stretch film from the supply roll to the packaging device. 
     The films are conveyed from a film dispensing device via a movable film guiding element to a film transport device. The film transport device has two synchronously operated belt conveyors arranged in parallel. The film is transported by the belt conveyors to a position in the packaging machine in which a product to be packaged can be brought to the film and be packaged in the film. The belt conveyors can be introduced into recesses of a guide plate of the film guiding element by the movement of the film guiding element. This defines a zero position of the belt conveyors. This ensures a reliable transfer of the film from the film guiding element into the film transport device. To “stretch” the film in its transverse direction, the second belt conveyor is movable a short distance relative to the first one. The guide plate is designed as a horizontal plate. 
     The known packaging machine, however, needs a relatively large space in the x direction. Furthermore, this often results in a sloppy transfer of the film. 
     The packaging machine is basically designed to package trays of varying size. However, the film transport device can only process films having a defined width. With smaller, that is narrower trays, this results in film being wasted that projects in width far past the tray and must be folded together under the product to be packaged. There is more film there than is actually necessary. In the total cost of packaging, the film constitutes a considerable cost factor, even compared to the tray and the label. Excessive film consumption can make this form of packaging uneconomical compared to other packages. 
     SUMMARY 
     In an embodiment, the present invention provides a packaging machine for packaging products to be packaged by means of a stretchable film, comprising: a film transport device for a film feed to a product to be packaged; a first and a second belt conveyor configured to transport the film, the belt conveyors each comprising a first and a second belt conveyor that are synchronously driven in a film transport direction prescribed by the film transport device and are arranged side by side, at least the second belt conveyor device being movable in a direction perpendicular to a film transport direction; and a movable film guiding element, by which the film is introducible into the film transport device, the film guiding element comprising a guide plate configured to guide the film that has a first recess and a second recess in an upper edge in a vertical direction toward the belt conveyors, the first belt conveyor being introducible into the first recess and the second belt conveyor into the second recess, thereby defining a first zero position with respect to a width of the film, wherein the guide plate of the film guiding element is vertically oriented, wherein the guide plate has at least a third recess along its edge facing toward the belt conveyors, the second belt conveyor being introducible into the third recess instead of the second recess in order to establish a second zero position with respect to the width of the film, and/or wherein at least the second recess of the guide plate is formed in a recess element which is displaceable along the upper edge of the guide plate in order to establish the second zero position with respect to the width of the film. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will be described in even greater detail below based on the exemplary figures. The invention is not limited to the exemplary embodiments. Other features and advantages of various embodiments of the present invention will become apparent by reading the following detailed description with reference to the attached drawings which illustrate the following: 
         FIG. 1  an isometric front view of a packaging machine for packaging products to be packaged; 
         FIG. 2  an isometric front view of a section of the packaging machine with belt conveyors and a film guiding element obliquely from above; 
         FIG. 3  a side view of one end of the belt conveyor with deflection rollers and guide rollers; 
         FIG. 4  an isometric view of a portion of the packaging machine with the belt conveyor and the film guiding element; 
         FIG. 5  an isometric rear view of the film guiding element and the film cutting device; 
         FIG. 6  an isometric view of the belt conveyors and the film guiding element in the open state; 
         FIG. 7  an isometric front view of the film guiding element and the lower side of the belt conveyors, the film guiding element being moved to its uppermost position; 
         FIG. 8  a longitudinal section of the guide plate of the film guiding element (see  FIG. 1 ) in a second embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     By contrast, in an embodiment, an object of the present invention is to modify a packaging machine of the type defined at the outset and a method of packaging in such a way that the packaging machine is more flexibly usable in its handling, and film consumption can be optimized for different sizes of the product to be packaged. 
     This object is achieved with regard to the device in a technically particularly simple and surprisingly effective manner by a generic packaging machine which is distinguished in that the guide plate of the film guiding element is vertically oriented, and the guide plate has at least one third recess along its edge toward the belt conveyors, the second belt conveyor being introducible into the third recess instead of the second recess in order to establish a second zero position with respect to the width of the film, and/or at least the second recess of the guide plate being formed in a displaceable recess element on the upper edge of the guide plate in order to establish the second zero position with respect to the width of the film. 
     As a rule, the belts are not guided into the recess; instead the plate is moved so that the belts are situated in the recesses when the plate is in the upper position. 
     The packaging machine according to the invention is relatively easily converted to film rolls of different width, and in fact even without a mechanical conversion on the packaging machine. 
     The spacing of the belt conveyors can be adapted to the respective width of the currently used film via the different zero positions without having to replace parts of the packaging machine for this purpose. This enables reliable transfer and reliable transport of films of different widths from the film guiding element into the belt conveyors of the film transport device. 
     In the first alternative of the invention which is particularly simple to produce, at least one third recess—in addition to the two known fixed recesses—is provided in the upper edge of the guide plate with which a further zero position can be set. 
     The same can be achieved in the second, somewhat more convenient alternative of the invention by means of a displaceable recess element on the upper edge in which the second recess is formed. This version of the invention also allows continuous instead of discrete adjustment of the first and all further zero positions. 
     As a result of the vertical alignment of the guide plate, the orientation of the film during the transfer from the film guiding element into the film transport device likewise takes place in the vertical direction. The film is thus transferred “standing,” does not bend as easily as in a vertical or oblique direction, and can therefore more reliably be guided between two belts and ultimately securely transferred. 
     The vertical alignment of the guide plate also allows a substantial reduction in the footprint of the packaging machine as compared to other alignments of the guide plate that are known in the art. 
     This results in a slightly different arrangement of the deflecting rollers than was described, for example, in EP 3 093 244 B1, which was cited at the outset. 
     In advantageous embodiments, in particular in the first alternative of the packaging machine according to the invention, the guide plate has, in addition to the first recess, more than two further recesses, in particular three further recesses, into which the second belt conveying device can be introduced in order to establish more than two zero positions. This enables the reliable processing of a strip of film having different widths. 
     A preferred embodiment of the packaging machine is wherein the distances of the first recess from the other recesses correspond to commercially available widths of plastic packaging films. The packaging machine can then be adjusted precisely to the width of commercially available films. 
     A preferred embodiment, in particular the second alternative of the packaging machine according to the invention, is wherein the height of the recess element in the vertical direction is greater than or equal to the height of the first recess, the upper edge of the guide plate being aligned with the upper edge of the recess element, and the height of the second recess in the recess element being equal to the height of the first recess. In this way, the belt conveying devices can be inserted particularly easily into the recesses with the same configuration at the same depth. 
     In a further embodiment of the packaging machine, the displaceable recess element is latchable in a latching device. This allows stable positioning of the recess element at the different zero positions. 
     An advantageous further development of this embodiment is wherein the latching device has various latching points along the top edge of the guide plate, the distances of which from the first recess correspond in particular to the widths of commercially available plastic packaging films. This allows the recess element to easily and quickly be positioned at the correct distances from the first recess. 
     The packaging machine according to a further preferred embodiment can be wherein there is a further guide plate which runs horizontally spaced apart from and parallel to the first guide plate, and which has recesses of the same design as the first guide plate, the film being transportable in the intermediate space between the two guide plates. By transporting the film between two guide plates, a foldover of the film is prevented more effectively. In particular when the two guide plates are arranged vertically, the force of gravity acts on the film only in a direction parallel to the plane of the film, not in a direction perpendicular to the plane of the film. Bending of the film in the direction perpendicular to the plane of the film is prevented on each side by a guide plate in each case. 
     An advantageous embodiment is wherein the packaging machine has deflection rollers, each of which guides one of the transport belts in continuous circulation and is arranged at the end in the respective transport belt, guide rollers for guiding the transport belts being mounted in the transport belts downstream of the deflection rollers relative to the film transport direction. 
     In a preferred further development of this embodiment, the belt conveyors each have a first, second, third, fourth, fifth and sixth guide roller. In this case, the first guide roller guides the strand of the first transport belt facing away from the second transport belt while forming a bend. The second and the third guide roller guide the strand of the first transport belt that faces toward the second transport belt. The fourth and fifth guide rollers guide the strand of the second transport belt that faces toward the first transport belt while forming a bend in each case. The sixth guide roller guides the strand of the second transport belt facing away from the first transport belt while forming a bend. This arrangement of deflection rollers and guide rollers makes it possible to transfer the transport belts from a substantially vertical orientation to a horizontal orientation. For this purpose, the first and second transport belts can rest against one another in order to transfer the bending of one transport belt to the other. 
     Another preferred embodiment is wherein, after introduction of the film into the film transport device for guiding the film to a product to be packaged, the belt conveyors can be distanced from one another at a distance in the direction perpendicular to the film transport direction in order to stretch the film. This has the effect that the film rests smoothly against the product to be packaged without wrinkles or gaps. 
     The packaging machine according to another advantageous embodiment can be wherein a product to be packaged, in particular a tray, can be transported between the belt conveyors to the film by means of a device for transporting the product to be packaged. The product to be packaged may be brought by a conveyor belt and a lifting table between the belt conveyors and thus easily be brought against the film. 
     In a further class of preferred embodiments, the packaging machine according to the invention comprises a film transport device in which the two opposing transport belts of a belt conveyor have a first and a second deflection roller. The deflection rollers each guide one of the transport belts in continuous circulation and are arranged at the end in the respective transport belt. The packaging machine in this further design is wherein the first deflection roller has an end portion that projects past its associated transport belts. The first deflection roller has a first transport ring at the end portion along its circumference. The second deflection roller has an end portion that projects past its associated transport belt. The second deflection roller has a second transport ring on the end portion along its circumference. 
     A first contact surface of the first transport ring extends with mechanical friction along the circumference of the first deflection roller. A second contact surface of the second transport ring extends with mechanical friction along the circumference of the second deflection roller. The contact surfaces rest against one another with frictional engagement. The end sections of the deflection rollers can securely grip the film by the frictional engagement and thus ensure a stable transfer of the film from the film guiding element into the film transport device. 
     The scope of the present invention also includes a method for packaging products to be packaged in a packaging machine according to the invention by means of an expandable film. The latter is introduced by a movable film guiding element into a film transport device for feeding film to a product to be packaged. In this case, the film is transported by the film transport device in a film transport direction. After transport of the film by the film transport device, the film is wrapped around a product to be packaged. When the film is introduced into the film transport device, a first belt conveying device is introduced into a first recess of a guide plate of the film guiding element, and a second belt conveying device is introduced into a second recess of the guide plate in order to determine a first zero position with respect to the width of the film. At least the second belt conveyor is movable in a direction perpendicular to the film transport direction. 
     The method is wherein the second belt conveyor is introduced into a third recess of the guide plate instead of the second recess in order to determine a second zero position with respect to the width of the currently used film. Alternatively, in order to establish the second zero position, the recess element on the upper edge of the guide plate is displaced, and the second belt conveyor is introduced into the second recess on the recess element. In this method, the spacing of the belt conveyors is adapted to the width of the film via the various zero positions without having to replace parts of the packaging machine for this purpose. The film can be transferred reliably and quickly from the film guiding element into the belt conveyors of the film transport device for different widths of the film. 
     An advantageous embodiment of this method is wherein the film guiding element with the guide plate is moved between a film dispensing device and the film transport device for supplying film to a product to be packaged in order to supply a film to the film transport device. This allows for reliable transfer of the film to occur at different distances between the film dispensing device and film transport device. 
     A further embodiment of the method is wherein the film is cut to a desired length of film by means of a film cutting device arranged upstream of the film transport device relative to the film transport direction. For introducing the film into the film transport device, the guide plates of the film guiding element are guided by the film cutting device. After the introduction of the film into the film transport device, the guide plates of the film guiding element are moved out of the cutting device, so that the blades of the film cutting device can cut the film. The film is thus cut to the desired length before the cut film piece is transported through the film transport device into a packaging position. 
       FIG. 1  shows an isometric front view of a packaging machine  10  according to the invention for packaging products to be packaged by means of an expandable film. 
     The packaging machine has a film transport device  11  for supplying film to a product to be packaged. A first belt conveyor  12   a  and a second belt conveyor  12   b  for transporting the film form components of the film transport device  11 . The first and second belt conveyors  12   a,    12   b  each have first and second transport belts  13   a,    13   b  (see  FIG. 2 ). The transport belts  13   a,    13   b  are driven synchronously in a film transport direction X predetermined by the film transport device  11  (in  FIG. 1  into the paper plane, represented by a cross) and arranged adjacent to one another. The second belt conveyor  12   b  is movable in a direction Y perpendicular to the film transport direction X by spindles  14   a,    14   b  and a spindle motor  15 . With a film guiding element  16  of the packaging machine  10  movable in the vertical direction Z, the film can be introduced into the film transport device  11  from a film dispensing device  17 . The term “vertical” relates in particular to the direction parallel to gravitational force. The film dispensing device  17  is formed below the film guiding element  16 , and the film transport device  11  is formed above the film guiding element  16 . The film guiding element  16  has a first guide plate  18   a  and a second guide plate  18   b  (see  FIG. 2 ). The guide plates  18   a    18   b  are vertically aligned. The film can be inserted between the guide plates  18   a,    18   b  via a deflecting roller  19  of the film guiding element  16  at the lower end of the film guiding element  16 . 
     A first recess  21   a  as well as a second, third and fourth recess  21   b,    21   c,    21   d  are formed in an upper edge  20  of the guide plate  18   a  in the vertical direction Z toward the belt conveyors  12   a,    12   b.  The film guiding element  16  is movable in the vertical direction Z. As a result, the guide plate  18   a  can be moved to the height of the belt conveyors. The border  22   a  of the first recess surrounds the first belt conveyor  12   a.  Depending on the position of the movable second belt conveyor  12   b,  the borders  22   b,    22   c,    22   d  of the second, third or fourth recesses  21   b,    21   c,    21   d  surround the second belt conveyor  12   b.  As a result, the belt conveyors  12   a,    12   b  are introduced into the recesses  21   a - 21   d.  The selection between the second, third or fourth recess  21   b - 21   d  is such that the spacing  23  of the belt conveyors  12   a,    12   b  in the recesses  21   a - 21   d  corresponds to the width of the film. This defines the zero positions of the belt conveyors with respect to the width of the film. When the second recess  21   b  surrounds the second belt conveyor  12   b,  this is referred to in the context of the application as “first zero position.” When the third recess  21   c  surrounds the second belt conveyor  12   b,  this is referred to in the context of the application as “second zero position.” Accordingly, one may refer to a “third zero position” if the fourth recess  21   d  surrounds the second belt conveyor  12   b.  Further recesses (not specifically illustrated in the drawing) can correspondingly determine further zero positions. 
     A film cutting device  25  is arranged in the vertical direction below the belt conveyors. The film is transported by the belt conveyors  12   a,    12   b  until the film has a sufficient length, as measured from the film cutting device  25 , for the desired packaging process. The film guiding element  16  with the guide plates  18   a    18   b  is then moved downward in the vertical direction toward the film dispensing device  17 . The guide plates  18   a,    18   b  of the film guiding element  16  thus exit the film cutting device  25 . The film cutting device  25  then cuts through the film. The cut-off film is then further transported by the belt conveyors  12   a,    12   b  until the cut portion of the film is arranged in a position vertically above a lifting table. The lifting table will later move the product to be packaged in a vertical direction. Thus, the cut portion of film is arranged vertically above the product to be packaged between the belt conveyors  12   a,    12   b.  The film is stretched by a movement of the belt conveyor  12   b  in the direction Y perpendicular to the film transport direction X. A product to be packaged, for example a tray, can be fed by a packaging product transport device to the film between the transport belts  13   a,    13   b.  Such a packaging product transport device may include a supply conveyor belt and a lifting table, as described in the above-cited EP 3,093,244 B1. When the product to be packaged is fed to the film by a lifting process, the film wraps around the product to be packaged. The film can be wrapped around the product to be packaged by folding claws. The product to be packaged can then be pushed by a pusher onto a sealing plate on which the film is welded and lastly can be transported away by a conveyor belt, as outlined in EP 3,093,244 B1. 
       FIG. 2  shows an isometric front view of a section of the packaging machine  10  with the belt conveyors  12   a,    12   b  and film guiding element  16  obliquely from above. For greater clarity, the film cutting device  25  is not shown in  FIG. 2 . In particular the first and second guide plates  18   a,    18   b  of the film guiding element  16  are shown, between which the film is transported. The belt conveyors  12   a,    12   b  have recesses  26  for the upper edge  20  of the guide plates  18   a,    18   b.  In the state where the belt conveyors  12   a,    12   b  are inserted into the recesses  21   a - 21   d,  the borders  22   a - 22   d  of the recesses  21   a - 21   d  surround the belt conveyors  12   a,    12   b.  The transport belts  13   a,    13   b  are guided in each case by a deflection roller  27   a,    27   b  arranged at the end in the transport belts  13   a,    13   b.  A first, second, third, fourth, fifth and sixth guide roller  28   a,    28   b,    28   c,    28   d,    28   e,    28   f  for guiding the transport belts  13   a,    13   b  are arranged downstream of the deflection rollers  27   a,    27   b  relative to the film transport direction X. 
       FIG. 3  shows a side view of one end  31  of the belt conveyor  12   b  with the deflection rollers  27   a,    27   b  and the guide rollers  28   a - 28   f.  The first guide roller  28   a  guides the strand  29   a  of the first transport belt  13   a  which faces away from the second transport belt  13   b  while forming a bend  30   a  which transfers the strand  29   a  which faces away from the second transport belt  13   b  from a substantially vertical orientation Z to a horizontal orientation H. The second and third guide rollers  28   b,    28   c  guide the strand  29   b  of the first transport belt  13   a  that faces toward the second transport belt  13   b.  The fourth and fifth guide rollers  28   d,    28   e  guide the strand  29   c  of the second transport belt  13   b  that faces toward the first transport belt  13   a  while forming a bend  30   b,    30   c,  these bends  30   b,    30   c  effecting a transfer of the strand  29   c  that faces toward the first transport belt  13   a  from a substantially vertical orientation Z to a horizontal orientation H. The sixth guide roller  28   f  guides the strand  29   d  of the second transport belt  13   b  that faces away from the first transport belt  13   a  while forming a bend  30   d,  the bend  30   d  transferring the strand  29   d  that faces away from the first transport belt  13   a  from a substantially vertical orientation Z to a horizontal orientation H. 
     In particular, it is shown that the transport belts  13   a,    13   b  rest against one another. As a result, the bends  30   b    30   c  of the strand  29   c  of the second transport belt  13   b  that faces toward the first transport belt  13   a  are transferred to the strand  29   b  of the first transport belt  13   a  that faces toward the second transport belt  13   b.  For transport, the film can be introduced between the two transport belts  13   a,    13   b  that rest against each other. 
     A spindle nut  32  of the belt conveyor  12   b  enables the belt conveyor  12   b  to be guided in the direction Y perpendicular to the film transport direction X (see  FIG. 1 ) via a spindle  14   a,    14   b  (see  FIG. 1 ) for adjusting the distance of the belt conveyors  12   a,    12   b.  The belt conveyor  12   a  remains fixed in the Y direction. The distance between the two belt conveyors  12   a,    12   b  can thereby be changed. 
       FIG. 4  shows an isometric view of a part of the packaging machine  10  with a belt conveyor  12   b  and the film guiding element  16 . The film guiding element  16  has a first motor  33   a  and a first gear drive  34   a  with a gear  35   a  to move the film guiding element  16 . The spindles  14   a,    14   b  for lateral movement of the belt conveyor  12   b  are rotated by the spindle motor  15  with a second gear drive  34   b.  Also shown is a second motor  33   b  for driving the belt conveyor  12   b.    
       FIG. 5  illustrates an isometric rear view of the film guiding element  16  and the film cutting device  25 . The movement of the film guiding element  16  is guided by the first gear drive  34   a  with gears  35   a,    35   b  and the first motor. The film is guided out of the film dispensing device  17  (see  FIG. 1 ) via a deflecting roller  19  of the film guiding element  16  and a rear guide roller  36  between the guide plates  18   a,    18   b  (in  FIG. 5 : guide plate  18   b ). The film cutting device  25  has a lifting magnet  33   c  for driving the movement of the blade of the film cutting device  25  for cutting through the film. 
       FIG. 6  shows an isometric view of the belt conveyors  12   a,    12   b  and the film guiding element  16  with the guide plates  18   a,    18   b  in the open state. The first guide plate  18   a  is folded open. This allows a film in the film guiding element  16  to be inserted between the two film plates  18   a,    18   b.  Once the film has been inserted, the guide plate  18   a  can be folded back, and the film guiding element  16  can thus be closed. 
       FIG. 7  shows an isometric front view of the film guiding element  16  and the lower side of the belt conveyors  12   a,    12   b,  the film guiding element  16  being moved to its uppermost position; The belt conveyors  12   a,    12   b  are in the first zero position. The first belt conveyor  12   a  is introduced into the first recess  21   a  and the second belt conveyor  12   b  into the second recess  21   b.  The film in the film guiding element  16  is inserted into the belt conveyors  12   a,    12   b  and thereby transferred to the film transport device  11 . 
       FIG. 8  shows a longitudinal section of the guide plate  18   a  of the film guiding element  16  (see  FIG. 1 ) in a second embodiment. The guide plate  18   a  has a displaceable recess element  37  in which the second recess  21   b  is formed. The height h 1  of the recess element  37  in the vertical direction Z is greater than the height h 2  of the first recess  21   a.  In this situation, the upper edge  20  of the guide plate  18   a  and the upper edge  38  of the recess element  37  are flush. The height h 3  of the second recess  21   b  is equal to the height h 2  of the first recess  21   b.  Then the first and second belt conveyors  12   a,    12   b  (see  FIG. 1 ) can be introduced into the first and second recess  21   a,    21   b  by displacement of the guide plate  18   a  with the movable film guiding element  16  (see  FIG. 1 ) after the second recess element  37  has been displaced to an appropriate location for establishing the zero position. For this purpose, the second recess element  37  can be latched in a latching device  39  having various latching points  40  along the upper edge of the guide plate, the distances of which from the first recess correspond to the commercially available widths of packaging films. The second guide plate  12   b  (not shown in  FIG. 6 ) is designed accordingly. 
     While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive. It will be understood that changes and modifications may be made by those of ordinary skill within the scope of the following claims. In particular, the present invention covers further embodiments with any combination of features from different embodiments described above and below. Additionally, statements made herein characterizing the invention refer to an embodiment of the invention and not necessarily all embodiments. 
     The terms used in the claims should be construed to have the broadest reasonable interpretation consistent with the foregoing description. For example, the use of the article “a” or “the” in introducing an element should not be interpreted as being exclusive of a plurality of elements. Likewise, the recitation of “or” should be interpreted as being inclusive, such that the recitation of “A or B” is not exclusive of “A and B,” unless it is clear from the context or the foregoing description that only one of A and B is intended. Further, the recitation of “at least one of A, B and C” should be interpreted as one or more of a group of elements consisting of A, B and C, and should not be interpreted as requiring at least one of each of the listed elements A, B and C, regardless of whether A, B and C are related as categories or otherwise. Moreover, the recitation of “A, B and/or C” or “at least one of A, B or C” should be interpreted as including any singular entity from the listed elements, e.g., A, any subset from the listed elements, e.g., A and B, or the entire list of elements A, B and C. 
     LIST OF REFERENCE NUMBERS 
     
         
           10  packaging machine 
           11  film transport device 
           12   a  first belt conveyor 
           12   b  second belt conveyor 
           13   b  first transport belt 
           13   b  second transport belt 
           14   a,b  spindles 
           15  spindle motor 
           16  film guiding element 
           17  film dispensing device 
           18   a  first guide plate 
           18   b  second guide plate 
           19  deflection roller 
           20  upper edge of the first guide plate 
           21   a  first recess 
           21   b  second recess 
           21   c,d  third and fourth recesses 
           22   a - d  borders 
           23  spacing of the belt conveyors in the recesses 
           25  film cutting device 
           26  recesses of the belt conveyors 
           27   a,b  deflection rollers 
           28   a - f  guide rollers 
           29   a - d  strands 
           30   a - d  bends 
           31  end of first belt conveyor 
           32  spindle nut 
           33   a  motor 
           33   c  solenoid 
           34   a,b  gear drive 
           35   a,b  gears 
           36  rear guide roller 
           37  displaceable recess element 
           38  upper edge of the recess element 
           39  latching mechanism 
           40  latching points 
         X horizontal transportation direction 
         Y horizontal direction perpendicular to X 
         Z vertical direction perpendicular to X and Y 
         h 1  height of recess element 
         h 2  height of the first recess 
         h 3  height of second recess