Abstract:
A method for making packs of in each case at least two coupled articles which are held together by a strap wherein said strap is tensioned in a horizontally manner about the outer surfaces of the articles. Said strap is laid about the articles during a continuous conveying process and fixed afterwards. 
     A device for handling, conveying, packing and/or palletizing articles, wherein said device includes at least a horizontal conveying means for continuously conveying articles, a device for making packs of in each case at least two grouped and coupled articles as well as a subsequent grouping device for arranging the packs opposite to other packs and for the subsequent making of pallet layers and/or for the preparation of a palletizing afterwards.

Description:
[0001]    This is a Continuation Application of U.S. patent application Ser. No. 12/878,730, filed Sep. 9, 2010 and claims the benefit of German Patent Application 10 2009 040 700.6, filed Sep. 10, 2009, both applications are hereby incorporated by reference herein. 
         [0002]    The present invention relates to a method for making packs. Besides, the invention relates to a device for handling, conveying, packing and/or palletizing articles. 
     
    
     BACKGROUND 
       [0003]    Various possibilities of combining single articles to larger packs are known. Thus, containers for beverages are for example combined and packed mostly by means of shrink films to packs of four, six or more containers. For the most part, the making of packs is inevitable since it is the most frequent type of sales units for containers of beverages and bottles made of PET plastic. The packs are partially once more combined for transport and/or assembled in layers and palletized. 
         [0004]    The shrink films used for the making of known packs are in need of certain manufacturing steps with high energy demand. Furthermore, the used films cause costs regarding the making, the supply, the handling as well as the later disposal since after the sale they are not needed anymore. Likewise, the equipment of the device for the supply of so called film wrapping modules and other handling stations causes immense investment costs. Finally, a relatively high employment of capital is also necessary for the supply of the so called shrinking tunnel, whereby the film, which is wrapped around the packs by means of hot air impingement, is being shrinked. 
       SUMMARY OF THE INVENTION 
       [0005]    An object of the present invention is to provide a cost-saving and an easily manageable possibility for making packs which at least partially avoids the mentioned drawbacks of the prior art. 
         [0006]    The present invention provides a method for making packs of in each case at least two coupled articles which are held together by strapping means wherein said strapping means is laid around the articles during a continuous conveying process and fixed afterwards. The articles are not stopped during the application of the strapping means since the strapping means is tensioned around the articles according to the invention in a continuous process at a time, during which they are being continuously conveyed. The strapping means is preferably a strap which is tensioned around the outer surfaces of the articles and afterwards fixed on each end in a pre-stressed state. Two or more straps running in a parallel manner can also form the strapping means, of course. Thus, the strapping means can be one, two or more straps made of rope material, wire, polymer, metal, paper or a composite material, which are fixed on its ends by gluing, welding, cramping, knotting or other. 
         [0007]    The application of the strapping means can be carried out in a variety of ways. Thus, the strapping means can be lowered from above over the articles, for example, wherein said articles are positioned on a horizontal conveying means and are moved in a horizontal direction, and applied by the strapping unit wherein said strapping means moves synchronically with the feed rate of the strapping unit and the horizontal conveying means. Alternatively, the strapping unit can be provided with a gantry robot, or buckling-arm robot with strapping head, which moves during the application of the strapping means in vertical direction over the articles and simultaneously moves in horizontal conveying direction of the articles with said articles. The strapping unit can be optionally fixed in a stationed position, wherein in each case two separate straps with supply reels are arranged in such a way that they can be connected in the middle so that a horizontal strap is being tensioned diagonally to the conveying direction of the packs. The pack is then moved continuously into this said stretched strap to the point until the rear edge of the formation is in line with the formerly even strap line. The movement of the formation of packs in conveying direction thus enforces a following conveyance of the straps from their supply reels so that the formation is now enclosed from three sides. If necessary, these reels can be provided with a self-powered drive and be controlled, for example, by means of light beams. 
         [0008]    Besides, it is also possible that the strapping unit shifts or rotates the articles, which are bound to packs after the application of the strapping means onto the surface area of the horizontal conveying means for arranging the articles opposite to other packs and for the subsequent making of pallet layers and/or for the preparation of a palletizing afterwards. In such a way, the strapping unit can advantageously be a part of a grouping device and either be used for a desired grouping of the packs before they are being palletized or otherwise. 
         [0009]    Another embodiment of the method according to the invention may provide the application and fixing of a carrier handle during or after the application of the strapping means onto the outer surface of the pack and/or onto the strapping means. If necessary, said carrier handle can contribute to the additional attitude stabilization of the formation of packs so that the containers of beverages can be slid against each other to a much lesser extent. 
         [0010]    Furthermore, the invention relates to a device for handling, conveying, packing and/or palletizing articles. The device comprises at least one horizontal conveying means for continuously conveying articles, a device for making packs of in each case at least two grouped and coupled articles as well as a subsequent grouping device for arranging the packs opposite to other packs and for the subsequent making of pallet layers and/or for the preparation of a palletizing afterwards. The device for making packs is provided according  t o the invention with a strapping unit for the application of a strapping means wherein said strapping means is arranged horizontally and tensioned onto the outer surfaces of the articles to be coupled together. The strapping unit is assigned to the horizontal conveying means and/or to the subsequent grouping device or can be an integral part of the horizontal conveying means and/or of the grouping device. The strapping unit can be optionally provided with a gantry robot, or buckling-arm robot with strapping head, which is movable during the application of the strapping means in vertical direction over the articles and is simultaneously movable in horizontal conveying direction of the articles with said articles. 
         [0011]    The straps can either be made of suitable polymer material, metal or composite material. It is particularly advantageous to use a recyclable material which consists of mono-material polymer or of a defined metal, for example. If necessary it is possible to use biodegradable material, too. The positioning of the straps onto the packs can optionally be carried out mechanically or by means of air pressure. Thus, alternatives are possible with which the strap is being conveyed in parts along its transport path by means of air pressure so that said strap largely positions itself around the pack in the desired position and is supportively carried mechanically. 
         [0012]    An advantage of the invention to known prior art is among other things the fact that the strapping means are less expensive than a film. No shrinking tunnel is necessary, which results in high energy saving and a reduction of the investment costs. When arranging the modules, the so called blocking, a smaller installation surface is necessary. In addition, not value adding functions such as transport, conveyance or the like can be reduced. Furthermore, the invention enables the avoiding of downtimes of the equipment and an increase of efficiency. On the basis of the modular design of the equipment parts, a modular installation facilitates to increase the lot sizes in production. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    Further features and advantages of the present invention shall now be described in greater detail according to the accompanying figures in the following detailed description. The dimensions of the individual elements to each other do not always correspond with the real dimensions since some forms are shown simplified and other forms are shown enlarged with respect to other elements for the sake of clarity. 
           [0014]      FIG. 1  shows a schematic perspective view of a dividing system as well as a transfer onto a conveyor belt for linear container formations. 
           [0015]      FIG. 2  shows a schematic perspective view of both a container division and of two strapping modules for double-lane mode. 
           [0016]      FIG. 3  shows a further view of the embodiment according to  FIG. 2 . 
           [0017]      FIG. 4  shows a top view onto the device according to  FIG. 3 . 
           [0018]      FIG. 5  shows another top view onto the arrangement with removed base frame. 
           [0019]      FIG. 6  shows a further perspective view onto the arrangement with removed base frame. 
           [0020]      FIG. 7  shows a perspective view of an arrangement with direct blocking of the strapping unit with a grouping station of a palletizing machine. 
           [0021]      FIG. 8  shows a perspective embodiment of an alternative strapping unit with stationary mounted strapping reels. 
           [0022]      FIG. 9  shows in four successive views the production steps when making a pack with a strapping unit according to  FIG. 8 . 
       
    
    
     DETAILED DESCRIPTION 
       [0023]    Same elements refer to same reference numbers throughout the various figures. Furthermore, only reference numbers which are necessary for the description of the respective figure are shown in the various figures for the sake of clarity. The shown embodiments are only examples of how the method according to the invention can be designed and shall not be regarded as limiting the invention. 
         [0024]    As for the method described in the following, packs and sales units respectively are being formed by strapping of containers by means of strings, straps made of different materials such as paper, polymer, metal, rubber and the like of rigid or flexible type. In the following, a possibility is described regarding how to integrate strapping applicators, which are manually loaded with products, from the package strapping into the machine technology of packaging conveyor lines. With ‘container strapping’, the strapping type at hand, basically all possible geometric arrangements of the containers are conceivable: linear matrix arrangement in a ‘n times m’-arrangement of lines and columns for round or rectangular, square or other containers as well as, for example, close packings at an angle of 30° and 60° degrees respectively with round articles in any desirable number. The arrangement of the packs depends on the feeding of the containers by means of the so called container divider. 
         [0025]    The idea for the invention is based upon the integration of strapping applicators in packaging conveyor lines, for example in one of the ways described in the following. The containers (round, rectangular or mould containers) to be strapped are divided into lanes by means of container feeders and conveyed to a container formation unit, for example a crank divider. The container formation unit forms container groups, which are fed to the strapping zone via a conveyor belt, out of the containers conveyed from the lanes. As for linear formations, the transport of the containers is carried out on the conveyor belt without guard railing and advance arbors. For products which are difficult to process or with diagonally staggered arrangements of packs, the transport of the containers through the strapping zone is carried out past the divider by advance arbors and railings. Diagonally staggered arrangements of containers, so called close packings, are formed by means of attachments onto the advance arbors. 
         [0026]    The schematic view of  FIG. 1  shows a dividing system  10  and the transfer onto a conveyor belt  12  for linear container formations. After forming desired pack formations  14  by means of a container divider and bringing the formations  14  in a defined distance by the divider, the grouped container formations pass  14  on a conveying means  16  the so called strapping zone  18  without relative motion between conveyor and formation. The strapping zone  18  consists either of minimal one strapping robot, also described as strapping module  20  in the following, or of a random number of successively loop-connected strapping modules  20  dependable on the required line efficiency. The processing and strapping respectively of the container formations can be carried out in the strapping modules  20  single-lane or multi-lane. 
         [0027]      FIG. 2  shows a container dividing system  10  and two strapping modules  20  for double-lane mode. 
         [0028]    As can be furthermore seen from  FIG. 3 , a strapping module  20  consists of a frame  22  and base frame respectively, into which two X and Z vertical axis are integrated. On each X an Z vertical axis, wherein said X and Z vertical axis are two linear axes with linear guiding and toothed belt drive, a so called strapping applicator  24  is mounted. 
         [0029]    The X axis of the double axes portal moves in container feeding direction, the Z axis in vertical direction; please see  FIG. 4 . 
         [0030]    The method for strapping the packs is described in the following, wherein reference is made to  FIGS. 1 to 4 . The container formations  14  are transported on the conveying means  16  by the strapping modules  20 . In each case a defined gap exists between the container formations  14 . After the entry of a container formation  14  in a strapping module  20 , the strapping applicators  24  move with the X and Z portal axes over the respective formation  14 , synchronize with the X axis regarding the feeding speed of the conveying means  16  and lower via the Z axis onto the strapping level. While the strapping head  24  moves with the container formation  14 , the formation is strapped by means of straps  26 , what can be seen from  FIG. 5 . The base frame has been removed in  FIG. 5  for the sake of clarity. Optionally, the strapping means can be a single strap  26 . Ideally, however, the strapping means consists of several overlapping straps  26  which are spaced from each other. 
         [0031]      FIG. 6  shows strapping application heads  24  with two strapping units  28  on top of each other. If the strapping unit consists of several strapping modules  20  (in this case: two modules shown), then the first module straps a formation row and allows the second formation row or, if necessary, the umpteen formation row to pass through. The second formation row or umpteen formation row is then being strapped by the second strapping module or umpteen strapping module  20 . Likewise, the base frame is removed in  FIG. 6 . 
         [0032]    As for the above shown machine technology also alternative embodiments are possible. Thus, the strapping application heads  24  can also be carried by buckling-arm robots instead of gantry robots. Thereby, the basic functional process does not change. Such buckling-arm robots can be arranged next to the conveyor means in any desirable number. 
         [0033]    One option can be the provision of the strapping application head with a strapping head for the application of carrier handles made of plastic straps. These carrier handles can be carried out in a self-adhesive manner, for example. 
         [0034]    The strapping modules are very suitable for the integration into packaging systems  30 . Thus, the strapping modules  20  can be integrated with the respective feed into conventional packaging-production lines as so called “stand-alone” - machinery. However, also the blocking of the strapping machine  31  with the palletizing machine  32  is possible. Thus,  FIG. 7  shows a direct blocking of the strapping unit  31  with the grouping station  34  of a palletizing machine  32 . Emerging packs from the strapping unit  31  are conveyed directly into the grouping station  34  which results in an advantageous process integration. 
         [0035]    On the other hand, a further embodiment can be that the strapping application heads are integrated in the grouping station  34  of a palletizing machine  32 . Before, during or immediately after the strapping of the packs, said packs are being grouped and brought into the desirable position on the conveying means  16  according to a given position scheme. Thus, it is also imaginable that the grouping station  34  with the integrated strapping application heads fulfils two tasks during a direct blocking in a packaging system, namely the making of packs and the grouping of packs to a pallet which can be palletized. 
         [0036]    A further alternative to the shown machinery technology can be the stationary position of the strapping reels  36 , as shown in  FIG. 8 . In this connection, in each case two separate straps with supply reels  36  are arranged in such a way that they are welded in the middle so that a horizontal strap  26  is tensioned diagonally to the conveying direction of the packs  14 . The pack  14  is then moved continuously into this said tensioned strap  26  to the point until the rear edge of the formation is in line with the formerly even strap line. The movement of the formation of packs  14  in conveying direction thus enforces a following conveyance of the straps  26  from their supply reels  36  so that the formation  14  is now enclosed from three sides. It can also be advantageous, if these reels  36  can be provided with a self-powered drive and actively provide the necessary line capacity after a respective signalizing (for example light beam signals ‘leading edge pack arrives’), so that the tension forces can be minimized on the formation in the movement period. When the pack  14  is enclosed from three sides with the strap  26 , the two fastening carriages  38 , which are arranged on the left and on the right next to the conveying line of the packs  14 , approach each other in one cutting stroke. The portal, onto which the fastening carriages  38  are conducting their closing in Y direction, must now simultaneously move together in conveying direction X with the pack  14  in order to enable a continuous flow. The fastening carriages  38  stretches the strap  26  around the formation and are sealing said strap. Simultaneously, the ends of the strap are cut off and sealed so that an even strap for the next pack is again provided. The portal with the fastening carriages  38  moves in opposition to the conveying direction back into its initial condition. 
         [0037]    The consecutive procedural steps are once again shown from top to bottom in the embodiment of  FIG. 9 . 
         [0038]    Depending on the requested capacity, the container formations which are to be strapped in a parallel manner can be strapped by feeding of two, three or more formations with a respective number of strapping applicators. 
         [0039]    The invention has been described with reference to preferred embodiments. To the person skilled in the art it is also conceivable, however, to make changes and modifications to the invention without leaving the scope of protection of the appended claims. 
       LIST OF REFERENCE NUMBERS 
       [0040]      10  dividing system
 
 12  conveyor belt
 
 14  pack, container formation
 
 16  conveying means or conveyor
 
 18  strapping zone
 
 20  strapping module
 
         22  Frame 
       [0041]      24  strapping applicator, strapping head
 
 26  strap, strapping means
 
 28  strapping unit
 
 30  packaging system
 
 31  strapping unit
 
 32  palletizing device
 
 34  grouping station
 
 36  strapping reel
 
 38  fastening carriage