Patent Publication Number: US-7908825-B2

Title: Method and device for producing cigarette packs

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is a National Stage of International Application No. PCT/EP2007/002967 filed Apr. 3, 2007, claiming priority based on German Patent Application No. 10 2006 024 559.8, filed May 23, 2006, the contents of all of which are incorporated herein by reference in their entirety. 
     Description 
     The invention relates to a method for producing (hard) packs, in particular cigarette packs of the hinge-lid-box type, with an outer wrapping of shrinkable film, wherein the packs which are provided with the outer wrapping are transported through a shrinkage station having heat elements, in particular having heating plates, for transmitting shrinkage heat to the packs. Furthermore, the invention relates to an apparatus for carrying out the method. 
     The shrinkage treatment of cigarette packs of the hinge-lid-box type with an outer film wrapping is known in principle. In the case of the apparatus according to one above another in a sealing sequence past heating plates. During a standstill phase, heat is transmitted to the upwardly directed large-surface-area pack sides, namely the front side or rear side with the packs lying one above another. The handling of the heating plates is difficult because of the arrangement between the pack rows lying one above another. 
     The invention is based on the object of proposing a method and apparatus for producing in particular cigarette packs, including shrinkage treatment, in which a high degree of efficiency with a precise result from the treatment are ensured. 
     To achieve this object, the method according to the invention is characterized by the following features:
     a) the packs are transported through the shrinkage station in two rows of individual packs lying next to each other, in particular in parallel, namely pack rows,   b) downstream of the shrinkage station the adjacent, mutually assigned packs of the two rows are brought together by transverse displacement with groups of in each case two packs lying one above the other being formed.   

     For the further processing of the packs, namely for the production of customary multipacks, “cigarette multipacks”, it is indispensable for the packs to be formed in groups of packs having their front side and rear side in contact with one another. This formation has proven disadvantage for the shrinkage process. Accordingly, for this region, the packs are conveyed and treated individually in two (parallel) pack rows and are then brought together with (two) groups being formed. 
     Accordingly, the apparatus according to the invention is provided, at least in the region of a shrinkage station, with two parallel pack conveyors which each convey one pack row, wherein, during a momentary standstill, in the region of the shrinkage elements, in particular the heating plates assigned to each pack row, the heating plates obtain contact with the upper side and/or lower side of the packs in order to transmit the predetermined shrinkage heat. 
     The pack conveyors are designed in such a manner that the lower side, namely front side or rear side of the packs, is free for contact by the heating plates. For this purpose, the packs are held on a pack conveyor, which runs above the packs or next thereto, by means of suction air and/or by means of mechanical holding elements. 
     In the positioning of the packs, which are supplied in two rows, in groups of packs lying one above another, there is a particular characteristic in that the packs arrive in offset planes in the region of a grouping station, to be precise in particular by means of pack conveyors which run with an upwardly directed or downwardly directed inclination and the vertical spacing of which substantially corresponds to the height of an individual pack in the region of a transverse displacement of the packs. 
    
    
     
       The method according to the invention and exemplary embodiments of the apparatus are explained in more detail below with reference to the drawings, in which: 
         FIG. 1  shows an apparatus for the treatment of (cigarette) packs as part of a packaging machine, in a schematic side view, 
         FIG. 2  shows the apparatus according to  FIG. 1  in a top view corresponding to the arrow II in  FIG. 1 , 
         FIG. 3  shows a detail of the apparatus according to  FIG. 1  and  FIG. 2  in cross section and in a transverse view in the plane of  FIG. 2  on an enlarged scale, 
         FIG. 4  shows a detail of  FIG. 2  in the transverse plane IV-IV of  FIG. 2 , likewise on an enlarged scale, 
         FIG. 5  shows a particular region of pack conveyors in a side view, namely the detail V in  FIG. 1 , on an enlarged scale, 
         FIG. 6  shows the detail according to  FIG. 5  in the case of a changed position of elements, 
         FIG. 7  shows a different exemplary embodiment of the apparatus in an illustration analogous to  FIG. 1 , 
         FIG. 8  shows the apparatus according to  FIG. 7  in a top view according to the arrow VIII in  FIG. 7 , 
         FIG. 9  shows the region of a shrinkage station in  FIG. 7  in a top view and in a horizontal section corresponding to the plane IX-IX in  FIG. 7 , on an enlarged scale, and 
         FIG. 10  shows a different exemplary embodiment of the apparatus in a schematic side view corresponding to  FIG. 1 . 
     
    
    
     The exemplary embodiments are concerned with the treatment of cuboidal packs  10 , namely cigarette packs of the hinge-lid-box type. The packs  10  are delimited by a large-surface-area front side  11 , an opposite rear side  12 , by side surfaces  13 ,  14  and by an end surface  15  and bottom surface  16 . The (hard) packs  10 , which are composed of thin cardboard, are surrounded by an outer wrapping of shrinkable film. 
     The packs  10  coming from a packaging machine are provided with the outer wrapping in the region of a film turret  17 . Said outer wrapping is initially folded in a customary manner in a shape of a U around the pack  10  as it is inserted into a pocket of the film turret  17 . Then, on the radially outer side surface  13 , folding tabs of the film are connected to each other in the region of an overlap by means of sealing. Furthermore, first foldings of the film in the region of the end surface  15  and bottom surface  16  are completed. 
     Directly downstream of the film turret  17 , the pack  10  passes into a rectilinear pack path. In the region thereof, the packs  10  first of all pass through a folding station  18  in which sideways directed folding tabs of the film wrapping are folded with customary end and bottom folds being formed. 
     This is followed by a sealing station  19 . In the region therefore, the folding tabs or folds are connected to one another in the region of the sideways directed end surface  15  and bottom surface  16  by thermal sealing. For this purpose, sealing elements, namely elongated sealing jaws  20 ,  21  are arranged on both sides of the pack path. The latter come into contact with the facing pack surfaces  15 ,  16  during a momentary standstill of the packs as they are being conveyed cyclically. The sealing jaws  20 ,  21  are therefore movable to and fro in the transverse direction. 
     The packs  10  which are completed with regard to the outer film wrapping now pass into a shrinkage station  22 . In the region thereof, heat is transmitted to the packs  10  in order to produce a shrinkage effect on the outer wrapping. 
     The finished packs  10  pass into the region of a grouping station  23 . The packs  10  are subsequently supplied in formed groups to a multipacker which produces customary multipacks from pack groups. 
     The shrinkage station  22  is designed in such a manner that heat is transmitted to the large-surface-area pack sides, namely to the front side  11  and rear side  12 , by heating elements, in particular by heating plates. During a treatment cycle, i.e. while the packs  10  are at a standstill, the heating plates preferably bear against the full surface area of said packs. For, this purpose, the packs  10  are conveyed in such a manner that the pack surface to be subjected to heat is exposed during the treatment. For this purpose, the packs  10  are conveyed in two pack rows  26 ,  27  running next to each other, to be precise, individual packs following one another at a distance, at least in the region of the shrinkage station  22 , and as early as in the region of the sealing station  19  and therebefore in the region of the film turret  17  in the present exemplary embodiments. In the shrinkage station  22 , the pack surfaces  11 ,  12  which are to be acted upon are kept free for contact by the respective heating plates by means of an appropriate design and manner of operation of pack conveyors. In the region of the grouping station  23 , the mutually assigned packs  10  of the pack rows  26 ,  27  are brought together by a transverse movement in order to form a pack unit  28  comprising in each case two packs  10  lying one above the other. 
     In the present exemplary embodiments, the packs  10 —coming from the packer—are supplied in two pack rows  26 ,  27  to the film turret  17 . The latter is designed in such a manner that two corresponding sub-turrets  29 ,  30  for in each case one pack row  26 ,  27  are combined to form a unit and are then moved synchronously. Downstream of the film turret  17 , the pack rows  26 ,  27  are guided through the folding station  18  and subsequently through the sealing station  19 . In the folding station  18 , folding elements are assigned to each pack row  26 ,  27 , and also respective sealing jaws  20 ,  21  are arranged on both sides of the pack rows  26 ,  27 . 
     In the exemplary embodiment according to  FIG. 1  and  FIG. 2 , the shrinkage station  22  is designed in such a manner that the upwardly directed front side  11  and downwardly directed rear side  12  of the packs  10  are acted upon in consecutive substations by heating plates. Heating plates are assigned to each pack row  26 ,  27 . In the first substation, heating plates  24 ,  25  are arranged below the path of movement of the pack rows  26 ,  27  such that the heating plates bear against the downwardly facing rear sides  12  of the packs  10 . The heating plates  24 ,  25  are dimensioned in such a manner that, during a treatment cycle, a plurality of packs  10 , namely three consecutive packs  10 , of a pack row  26 ,  27  are acted upon simultaneously by contact by the heating plates  24 ,  25 . The conveying cycles of the pack rows  26 ,  27  correspond in each case to one pack  10  such that the heat is transmitted to the packs  10  over a plurality of cycles (three). 
     In the following substation, heating plates  45 ,  46  are arranged above the pack rows  26 ,  27  such that the upwardly directed front side  11  is acted upon. 
     The pack conveyors for transporting the individual packs  10 , with the two parallel pack rows  26 ,  27  being formed, are designed in a particular manner. In the exemplary embodiment according to  FIG. 1  and  FIG. 2 , the packs are removed from the film turret  17  by a (first) pack conveyor  31 , which is designed as an endless conveyor, and are transported by an upper conveyor strand  32  along a first portion of a conveyor section. The pack conveyor  31  is designed in such a manner that the packs  10  are positioned in a substantially fitting manner between carry-along means  33 ,  34  arranged at a distance from each other. The latter grasp each pack  10  on pack surfaces located at the front and rear in the transporting direction, namely on the side surfaces  13  and  14 . 
     Each pack row  26 ,  27  is assigned one such pack conveyor  31 . The latter run parallel to one another and are driven synchronously such that the packs  10  of the pack rows  26 ,  27  are transported in an aligned formation. After emerging from the film turret  17 , the packs  10  are conveyed through the folding station  18  and subsequently through the sealing station  19 . The latter extends into the region of the shrinkage station  22 . The pack conveyor  31  ends at the shrinkage station  22 . 
     Subsequently, namely particularly in the region of the heating plates  24 ,  25  acting on the lower side of the packs  10 , the transportation of the packs  10  is taken over by a connecting conveyor assigned to each pack row  26 ,  27 , to be precise by a respective upper conveyor  35 . The latter is designed in an identical or similar manner to the pack conveyor  31 , namely with transversely directed carry-along means  36 ,  37  for grasping the packs  10  at the side surfaces  13 ,  14 . The packs are conveyed by a lower strand  38  in such a manner that the downwardly directed pack surfaces, namely the rear sides  12 , are exposed for contact by the heating plates  24 ,  25 . 
     The upper conveyor  35  is designed in such a manner that, when the heating plates  24 ,  25  are lowered, i.e. in particular during the conveying cycle, the packs  10  are held on the conveyor. For this purpose, the upper conveyor  35  is designed as a suction conveyor. The lower strand  38  is assigned a suction unit, namely a suction box  40 . The latter is connected to a negative pressure source in such a manner that suction air is transmitted to the packs  10  at least during the conveying cycle. The belt of the upper conveyor  35  is of air-permeable design. 
     The packs  10  are transported only in the region of the first substation, i.e. in the region of the downwardly acting heating plates  24 ,  25 , by the upper conveyor  35 . The packs are then taken on by the lower conveyor  41 ,  42  as a subsequent pack conveyor, the lower conveyor transporting the packs in the region of the heating plates  45 ,  46  acting on the upper side. This (third) pack conveyor extends into the region of the grouping station  23 . The lower conveyor  41 ,  42  is expediently designed like the pack conveyor  31  with an upper strand  43 ,  44  for transporting the packs  10  between front and rear drivers  33 ,  34 . 
     The grouping station  23  following the shrinkage station  22  is designed in such a manner that packs  10  of the two pack rows  26 ,  27 , which packs arrive in offset planes, are brought by transverse displacement into a position with packs arranged in pairs one above another ( FIG. 4 ). The planes which are offset in height are provided by the feed conveyors for the packs  10 , namely the lower conveyors  41 ,  42  and the upper strands  43 ,  44  thereof bringing about the height offset of the arriving packs  10  on account of being correspondingly inclined. For example, the upper strand  43  is inclined downward, the upper strand  44  is inclined upward, but may also run horizontally. 
     If heating plates  45 ,  46  are arranged in the region of the inclined upper strands  43  and/or  44 , the shape of the heating plates is matched to the position of the packs  10 , namely to the inclined conveying position. A contact surface of the heating plates  45 ,  46 , which contact surface faces the pack surfaces (front side  11 , rear side  12 ), is arranged obliquely corresponding to the inclination of the packs  10  such that the heating plates  45 ,  46  can bear over their entire surface area against the obliquely directed packs  10 . 
     In the grouping station  23 , the packs  10  are pushed in the transverse direction off the two upper strands  43 ,  44  by transverse conveyors, namely slides  47 ,  48 , and are deposited lying one above another on a support, namely on a platform  49 . The two-pack groups of packs  10  are taken from the latter by a removal conveyor  50 , namely an endless conveyor, which grasps the packs  10  by means of carry-along means  51  supplied from below and transports them away. The packs  10  are transported along a guide  52  of curve design and are transferred in groups in an upright position to a belt conveyor  53  which conveys away the packs  10  between upright strands, in particular to a multipacker. 
     An ejection station  54  is arranged upstream of the grouping station  23  in the conveying direction, i.e. between shrinkage station  22  and grouping station  23 . In the region of said ejection station, faulty packs identified during the manufacturing and transportation are separated out. The ejection station  54  is equipped with transverse conveyors  55 ,  56 . The latter are designed as belt conveyors with carry-along means  57  arranged at suitable distances from one another. The transverse conveyors  55 ,  56  are arranged movably above the lower conveyors  41 ,  42 , namely such that they are pivotable about a drive shaft  58 . In this starting position (on the right,  FIG. 3 ), the transverse conveyor  56  is located above the lower conveyors  41 ,  42  in the inoperative position. If a faulty pack passes into the region of the ejection station  54 , the relevant transverse conveyor  55  is lowered into the conveying position and driven. As an alternative, the transverse conveyors  55 ,  56  can be permanently driven and only lowered into the active position if the need arises. The relevant pack  10  is supplied to an ejection shaft  59 . 
     The concept of the exemplary embodiment according to  FIG. 7  to  FIG. 9  is similar to the concept of the exemplary embodiment according to  FIG. 1 . The individual packs  10  which were transported into paths are removed from the film turret  17  by the pack conveyor  31  and are supplied via the sealing station  19  to the shrinkage station  22 . The latter is constructed in such a manner that the lower heating plates  24 ,  25 , which are assigned to each pack row  26 ,  27 , and the upper heating plates  45 ,  46  are arranged one above the other. As a result, the shrinkage station  22  is shorter. In order to supply the heat preferably simultaneously to the upper side and lower side of the packs  10 , a special intermediate conveyor  60 ,  61  is required for transporting the packs  10  in the region of the heat elements in such a manner that the upper side and lower side of the packs  10  are exposed. The intermediate conveyors  60 ,  61  assigned to each pack row  25 ,  26  comprise two conveyor belts  62 ,  63 , in each case on both side of the path of movement of the packs  10 . The conveyor belts  62 ,  63  are designed with a small constructional width, i.e. with deflecting rollers of small diameter. The conveyor belts  62 ,  63  have transversely directed carry-along means  64 ,  65  which grasp the packs  10  on the front and rear side surfaces  13 ,  14 . The distances between the carry-along means  64 ,  65  assigned to a pack  10  correspond to the dimensions of the pack  10  such that said packs are transported in a manner free from play. By means of the design and arrangement of the intermediate conveyor  60 ,  61 , the front side  11  and the rear side  12  of the packs are free in the region of the heating plates  24 ,  25  and  45 ,  46 . 
     In order to ensure a small distance between the two transporting paths for the packs  10 , the intermediate conveyors  60 ,  61  and the conveyor belts  62 ,  63  of the two pack rows  26 ,  27  are arranged offset with respect to each other in the conveying direction ( FIG. 9 ) in such a manner that the carry-along means  64 ,  65 , which lie in pairs next to each other, protrude from the return strands of the mutually adjacent conveyor belts  62 ,  63  into the intermediate spaces of the respectively adjacent conveyor in an alternating manner. 
     Downstream of the shrinkage station  22  and of the intermediate conveyor  60 ,  61 , the packs  10  are transported to the grouping station  23  by a further pack conveyor, namely by the lower conveyor  41 ,  42  which is formed with the shorter upper strand  43 ,  44 . Said lower conveyor is designed analogously to the exemplary embodiment according to  FIG. 1  and  FIG. 2 . 
     An apparatus having a lower technical outlay is shown in  FIG. 10 . The shrinkage station  22  merely comprises upper heating plates  45 ,  46  for the upper side, i.e. front side  11 , of the packs  10  which are transported in two pack rows  26 ,  27 . Given appropriate material for the outer wrapping for the packs, the supply of heat merely to the upper side of the packs  10  is sufficient in order to obtain a shrinkage effect. 
     The two pack rows  26 ,  27  are each assigned a pack conveyor  66  which conveys the packs  10  from the film turret  17  via the folding station  18 , the sealing station  19 , the shrinkage station  22  to the grouping station  23 . 
     In the exemplary embodiment according to  FIG. 10 , an upper strand  67  of the pack conveyor  66  is divided into portions. An end portion  68  facing the grouping station  23  is guided via a deflecting roller  69  and inclined (downward). The heating plates  45 ,  46  are located in the region of said end portion  68  and are designed in the described manner if they are assigned to an end portion  68  running in an inclined manner. The heating plates  45 ,  46  have a trapezoidal cross section. 
     A further particular characteristic is the transfer of the packs  10  of a pack row  26 ,  27  from a pack conveyor to a subsequent pack conveyor. This characteristic is illustrated in  FIG. 5  and  FIG. 6  with reference to the example of  FIG. 1 . The two pack conveyors, namely the supplying pack conveyor  31  and the removing upper conveyor  35 , are arranged with an alternating overlap on account of appropriate positioning of deflecting rollers  70 ,  71 . The two conveyors are provided with carry-along means  33 ,  34 , on the one hand, and  36 ,  37 , on the other hand, which grasp the packs  10  on both sides. The mutually assigned carry-along means  33  . . .  37  differ in design with regard to their shape. In the case of the arriving conveyor, i.e. the pack conveyor  31 , web-like carry-along means  33  which have a bead-like thickening  72  of rounded cross section at the outer, free edge are effective on the front side of the packs  10 . Said thickening bears against the front side of the pack  10 . The opposite carry-along means  34  is a transversely protruding web with a bevel  73  on the side facing the pack  10 . The carry-along means  36 ,  37  are of corresponding design. 
     The arriving packs  10  are carried along by the pack conveyor  31  into the region of the upper conveyor  35  ( FIG. 5 ). By means of the subsequent deflection of the conveying element, the front carry-along means  36  passes into an oblique position. The rear carry-along means  34  comes free from the pack  10  since, on account of the deflection of the upper conveyor  35  which is taking over the pack, the carry-along means  33  bears against the rear pack surface (by means of the thickening  72 ) and takes over the further transportation of the pack, to be precise initially until contact is made with the carry-along means  37  of the upper conveyor  35 , which carry-along means bears against the front side. The pack  10  is therefore inserted between the carry-along means  36  and  37  of the upper conveyor  35  in a manner free from play. As the movement continues, the rear carry-along means  34  of the supplying pack conveyor  31  can be moved without contact past the transported-away pack  10 , namely past a lower, rear pack edge, because of the bevel  73  ( FIG. 6 ). 
     LIST OF REFERENCE NUMBERS 
     
         
           10  Pack 
           11  Front side 
           12  Rear side 
           13  Side surface 
           14  Side surface 
           15  End surface 
           16  Bottom surface 
           17  Film turret 
           18  Folding station 
           19  Sealing station 
           20  Sealing jaw 
           21  Sealing jaw 
           22  Shrinkage station 
           23  Grouping station 
           24  Heating plate 
           25  Heating plate 
           26  Pack row 
           27  Pack row 
           28  Pack unit 
           29  Sub-turret 
           30  Sub-turret 
           31  Pack conveyor 
           32  Conveyor strand 
           33  Carry-along means 
           34  Carry-along means 
           35  Upper conveyor 
           36  Carry-along means 
           37  Carry-along means 
           38  Lower strand 
         
           39 
         
           40  Suction box 
           41  Lower conveyor 
           42  Lower conveyor 
           43  Upper strand 
           44  Upper strand 
           45  Heating plate 
           46  Heating plate 
           47  Slide 
           48  Slide 
           49  Platform 
           50  Removal conveyor 
           51  Carry-along means 
           52  Guide 
           53  Belt conveyor 
           54  Ejection station 
           55  Transverse conveyor 
           56  Transverse conveyor 
           57  Carry-along means 
           58  Drive shaft 
           59  Ejection shaft 
           60  Intermediate conveyor 
           61  Intermediate conveyor 
           62  Conveyor belt 
           63  Conveyor belt 
           64  Carry-along means 
           65  Carry-along means 
           66  Pack conveyor 
           67  Upper strand 
           68  End portion 
           69  Deflecting roller 
           70  Deflecting roller 
           71  Deflecting roller 
           72  Thickened portion 
           73  Bevel