Abstract:
In order to produce (cigarette) packs with an insert blank ( 25 ) applied within the pack or to the outside of the latter, this insert blank is fixed temporarily by virtue of the pack or pack contents being electrostatically charged in the region of the insert blank ( 25 ). The pack is completed while the static charge is active, with the result that, by way of pack blanks, the insert coupon ( 25 ) is fixed in the envisaged position by the pack itself.

Description:
BACKGROUND OF THE INVENTION 
     The invention relates to a method of producing packs, in particular cigarette packs, which have a separate blank made of thin material as a pack insert—insert blank—in particular a coupon, a revenue stamp or the like, the insert blank being arranged in or on the pack and being enclosed by at least one pack blank. The invention also relates to an apparatus for implementing the method. 
     It is increasingly common in the cigarette industry for the cigarette packs to have printing carriers, namely coupons, made of a separate blank added to them. The coupons contain information for the consumer, advertising, etc. One difficulty is to introduce the pack inserts into the packs during the packing process without the operating procedure being adversely affected. Different solutions are known for this purpose, e.g. arranging the coupon within the pack, on the pack contents (cigarette block), or on the outside of the pack (hinge-lid box, soft carton), with the result that the coupon is enclosed externally merely by the outer wrapper made of film, which is customary for cigarette packs. 
     SUMMARY OF THE INVENTION 
     The invention deals with the production of, in particular, cigarette packs with at least one insert blank which is enclosed by at least one pack blank. The object on which the invention is based is to ensure that the pack insert, which comprises a separate blank, is retained in a precise predetermined relative position during the production process for the packs. 
     In order to achieve this object, the method according to the invention is characterized in that the blank—insert blank—is fixed at least temporarily on the pack or on a sub-pack by electrostatic charging of the material. 
     The invention is based on the knowledge that the coupon, which is fed by a separate subassembly—coupon dispenser—and positioned on the (sub-)pack, is displaced on the pack during continued transportation, on account of accelerating and centrifugal forces, before the pack is engaged by the folding process continuing or by a further pack blank. The electrostatic charging of the pack or sub-pack results in the insert blank, which is already in position or is fed following the charging operation, being fixed in position in a stable manner. This electrostatic retaining force then automatically loses its effect. Up to that point, the packaging process has continued to the extent where the insert blank is retained in the desired position by the pack itself. 
     In the case of the apparatus according to the invention, an electrostatic charging means, in particular a charging electrode, is positioned in the region of a conveyor for the packs or sub-packs, namely above the movement path. This charging electrode is directed towards the pack, which is conveyed continuously or is at rest during the electrostatic charging. It is possible here, according to the invention, for the electrostatic charging to take place immediately before the insert blank is applied or once the blank has been positioned on the (sub-)pack. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further special features of the invention are explained in more detail hereinbelow with reference to the drawings, in which: 
         FIG. 1  shows a schematic side view of a packaging machine for producing cigarette packs, 
         FIG. 2  shows, on an enlarged scale, a detail of the packaging machine according to  FIG. 1  in a plan view corresponding to view plane II—II in  FIG. 1 , 
         FIG. 3  shows, on a further-enlarged scale, a detail of  FIG. 2  in a side view corresponding to arrow III from  FIG. 2 , 
         FIG. 4  shows a perspective illustration of a cigarette pack, namely a hinge-lid box, during production of the same, 
         FIG. 5  shows a (cigarette) pack in side view with the insert blank placed in position (transverse view V—V in  FIG. 8 ), 
         FIG. 6  shows a schematic side view of a detail of another embodiment of a packaging machine, 
         FIG. 7  shows, on an enlarged scale, a transverse view of part of the apparatus according to  FIG. 6 , and 
         FIG. 8  shows, on an enlarged scale, a further detail, namely detail XIII of  FIG. 6 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The invention is concerned with the production of packs  10 , in particular cigarette packs. A pack  10  of the hinge-lid-box type is shown as a preferred example ( FIG. 4 ). This pack comprises a pack blank  11  made of thin cardboard, which forms a box part  12  and a lid  13 . The pack contents are formed by a group of cigarettes wrapped in an inner blank made of paper, film or tin foil, with a cigarette block  14  being formed in the process. This type of pack also contains a collar  15  comprising a separate blank. 
     For the production and filling of a pack  10  of the abovementioned type in a packaging machine according to  FIG. 1 , the pack blanks  11  are fed one after the other to a folding turret  16 . In the case of the present exemplary embodiment, the folding turret  16  is of plate-like design and is driven in rotation (cyclically) about a vertical axis. The packaging machine according to  FIGS. 1 and 2  is set up for double-track operation. In each case two adjacent pockets  17 ,  18  of the folding turret  16  are simultaneously charged with a pack blank  11 . The latter is folded on a preliminary basis here to achieve a folding position, with upright side tabs  19  and corner tabs  20  within the pockets  17 ,  18 , which is L-shaped or angled in longitudinal section ( FIG. 4 ). A base wall and following lid base wall and lid end wall  21  and lid front wall  22  extend in the plane of the rear walls or in the plane of base walls of the pockets  17 ,  18 . A radially inner upright leg of the pack blank  11  comprises a base wall and a following box front wall  31 . 
     In the folding position according to  FIG. 4 , the pack blanks  11  in the pockets  17 ,  18  are held ready in order to receive in each case one cigarette block  14  ( FIG. 2 ). The cigarette blocks, which are produced elsewhere, are transported to the folding turret  16  on a block path  32 , which runs radially in relation to the folding turret, and are pushed into the partially folded pack blanks  11  in the pockets  17 , 18  (position according to  FIG. 4 ). 
     Before the cigarette block  14  is pushed into an associated pack blank  11 , a collar  15  which has been folded in a U-shaped manner is positioned on the top side of the cigarette block  14 . The non-folded blanks for the collar  15  are fed to the cigarette blocks  14  on a collar path  23 , in a direction transverse to the block path  32 , and, with u-shaped folding, are deposited on a cigarette block  14  in each case such that a collar front wall  24  butts against the large-surface-area top side of the cigarette block  14 . 
     The packs  10  receive an insert, to be precise a printing carrier in the form of a separate insert blank  25  made of paper or of some other thin material. Each pack  10  receives such an insert blank  25 . In the case of the exemplary embodiment according to  FIG. 4 , this insert blank is positioned within the pack  10 , namely within the hinge-lid box, to be precise with abutment against the cigarette block  14  and beneath the collar front wall  24 . The dimensions of the insert blank  25  cause the latter to extend over most of the region of an upwardly directed large-surface-area side of the cigarette block  14  ( FIG. 4 ). 
     The operations of feeding the insert blank  25  and introducing the same into the pack  10  are integrated in the production process. In the present case, the insert blank  25  is positioned on the top side of the cigarette block  14  as the latter is transported along the block path  32 . For this purpose, a feeding subassembly, namely a coupon dispenser  26 , is arranged in the packaging machine ( FIG. 1 ), above each block path  32 . This coupon dispenser feeds the insert blanks  25  one after the other from above and positions them on each pack  10  or on each cigarette block  14 . In the production of a hinge-lid box, the collar  15  is then positioned on the cigarette block  14  or on the insert blank  25 . The unit which has been formed in this way is pushed into the pockets  17 ,  18 , or into the partially folded blanks  11 , by a pushing-in mechanism  27  in the region of a pushing-in station  33 . 
     The insert blanks  25 , which rest loosely on the packs  10  or the cigarette blocks  14 , may be displaced by forces which arise during transportation of the packs  10  or cigarette blocks  14 , in particular if a folding turret  16  is accelerated from a standstill. In order to fix the insert blanks  25  on the pack  10  or on the cigarette block  14 , an electrostatic charge is generated. This causes the insert blank  25  to adhere to the pack  10  or to the cigarette block  14  over its entire surface area. 
     The electrostatic charging can take place as early as in the region of the conveying section, that is to say in the region of the block path  32 . In the case of the exemplary embodiment shown, means for electrostatically charging the pack  10  or the cigarette block  14  and the insert blank  25  are positioned on the folding turret  16 , namely above the pockets  17 ,  18  in the pushing-in station  33 . These means are charging electrodes  28 ,  29  for each pocket  17 ,  18 . 
     The charging electrodes  28 ,  29  are positioned (in a stationary manner) above the packs  10  such that an approximately conical electric field  30  is transmitted to the packs  10  or the cigarette block  14 . The electric field  30  covers, in particular, an exposed region of the insert blank  25  beneath and/or alongside the collar  15 . However, the electric field  30  may be such that the collar  15 , in the correct position for the pack, is also covered by the electrostatic charging. Furthermore, the charging electrodes  28 ,  29  may be controlled such that an electrostatic field  30  is generated even as the cigarette block  14  is being pushed into the associated pack blank  11 . The charge acts such that the insert blank  25  butts against the upwardly directed side or wall of the cigarette block  14  over its entire surface area. The retaining effect lasts for a limited period of time, at least until the insert blank  25  is fixed definitively within the pack, in particular by virtue of parts of the blank being folded over, in this case by virtue of the initially upright box front wall  31  being folded over against the top side of the cigarette block  14 . 
     As an alternative, or in addition, it is possible for the charging electrodes  28 ,  29  or a single charging electrode to be positioned outside the region of the pushing-in station  33 , in the movement path of the packs  10  or of the insert blanks  25 , above the folding turret  16  (dashed illustration in  FIG. 2 ). In this case, the pockets  17 ,  18  with their contents, that is to say pack blanks  11 , cigarette block  14 , collar  15  and insert blank  25 , are moved past the stationary charging electrode and electrostatically charged one after the other. The power of the charging electrodes  28 ,  29  is expediently adjustable, to be precise up to a voltage of 30 KV (continuous voltage). The machine is earthed. 
     The effect of the electrostatic charge, surprisingly, allows optimum temporary fixing of multi-layered insert blanks  25 .  FIG. 5  shows a strip-like insert blank  25  folded in zigzag form, that is to say a multi-layered blank. The right-hand half of the illustration of the pack shows the insert blank  25  in a position in which it has not been subjected to electrostatic action, in which case the layers, on account of the material stressing not having been eliminated, are spaced apart from one another. The left-hand half of the figure shows that the electrostatic charging presses the plurality of layers against one another in a manner similar to a suction effect, with the result that the insert blank  25 , which has been folded a number of times, attains a flat formation which is desirable for the packaging process. 
     The fixing of an insert blank  25  may be desirable or advantageous during rectilinear conveying.  FIGS. 6 to 8  show a solution, by way of example, in which the insert blank  25  is positioned on the outside of a finished pack  10 , the latter being a cigarette pack of the hinge-lid-box type, with a box part  12  and lid  13 . The insert blank is positioned on an upwardly directed rear side or rear wall  34  of the hinge-lid box. 
     In order to transfer the insert blanks  25  to the upwardly directed side of the packs  10 , use is made of a specifically designed coupon dispenser  26 , which essentially comprises a belt conveyor  35  which has been angled a number of times. The insert blanks  25  are transported at regular intervals from one another by a conveying strand  36 , which has carry-along means  37  for each insert blank  25 . A transfer means, to be precise a transfer wheel  38 , is arranged in the region of a bottom leg of the coupon dispenser  26 . This transfer wheel is positioned in the center between individual belts of the belt conveyor  35  and effects a rolling movement on the top side of the pack  10  while, at the same time, transferring the insert blank  25 . 
     For electrostatic charging purposes, a means for generating an electrostatic field is arranged in the region where the insert blank  25  is transferred to the pack  10 . This means is formed by two charging electrodes  28 ,  29 , which are positioned on both sides of the belt conveyor  35  and of the transfer wheel  38 . End pieces  39  of the charging electrodes  28 ,  29  are angled towards one another, with the result that, in the region of the packs  10 , an electric field can be directed specifically towards border and/or end regions of the insert blanks  25 . This ensures that at least (top and bottom) sub-regions of the insert blank  25  are fixed by electrostatic charging. 
     The pack  10  provided with the electrostatically fixed insert blank  25 , following the coupon dispenser  26 , passes, by continued transportation, into the region of a wrapping station  40 . In the region of the latter, an outer wrapper made of film is folded around the pack  10  in a known manner, to be precise with the insert blank  25  being included in the process. In a first folding step, the pack  10 , which is conveyed in a state in which it lies transversely, is enclosed in a U-shaped manner by a blank of the outer wrapper. By virtue of the pack  10  and blank of the outer wrapper being pushed into a pocket of a folding turret, the insert blank  25  is fixed mechanically at the same time. In this example, the electrostatic charging takes place as the packs  10  are transported continuously along a pack path  41  by carry-along means  42 . 
     It is also possible for packaging machines or apparatuses for transporting packs  10  with an insert blank  25  placed in position to have a plurality of charging electrodes provided in different positions in order, repeatedly during the production process of a pack, to fix blanks on this pack or to renew a decreasing effect of the electrostatic charge.