Abstract:
A blank for forming a carton for packaging a plurality of articles includes a series of hingably interconnected top, first side, bottom and second side panels for forming an open ended sleeve capable of receiving articles. The top and bottom panels are similarly non-rectangularly shaped substantially to correlate with the cross-sectional shape of the array of articles in a plane parallel to the top and bottom panels. Each side panel has a plurality of panel portions including a pair of opposite end panel portions and at least one medial panel portion. The panel portions of each side panel are foldably interconnected by fold regions. Each side panel is adapted to be folded so as to put its end and medial panel portions into at least three different planes to conform with the respective shapes of the top and bottom panels. The blank further includes a pair of gussets provided for each side panel. Each gusset includes two hingably interconnected gusset panels. The pair of gussets connect one of the panel portions of each side panel to the top or bottom panel. Alternatively, the pair of gussets connect adjacent panel portions of each side panel to the top or bottom panel.

Description:
This is a continuation of application Ser. No. 08/860,811, filed Sep. 11, 1997 now U.S. Pat. No. 6,019,276, which is hereby incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     The invention relates to blanks for forming cartons useful in packaging a plurality of articles such as cans or bottles of drink for example, and more particularly to carton blanks for packaging articles in a non-rectangular array to form, for example, a fully enclosed carton. 
     A known carton having an octagonally shaped base and top panel is disclosed by Chaussadas in U.S. Pat. No. 4,747,485. The carton comprises a large number of separate panels for closing the sides and ends of the carton. A separate panel is hingably connected to each of the eight edges of the top and base panels. The majority of these panels depend only substantially halfway between the associated top or bottom panel and the opposite bottom or top panel and therefore overlap an associated panel depending from the opposite top or bottom panel. A relatively complex method of folding various panels is therefore required in order to close the carton shown in U.S. Pat. No. 4,747,485. 
     SUMMARY OF THE INVENTION 
     The invention seeks to avoid or at least mitigate various problems with prior art cartons. According to one aspect of the invention there is provided a blank for forming a carton for packaging a plurality of articles comprising a series of hingably interconnected top, first side, bottom and second side panels for forming an open ended sleeve capable of receiving said articles, the top and bottom panels being similarly non-rectangularly shaped substantially to correlate with the cross-sectional shape of the array of articles in a plane parallel to said top and bottom panels, wherein a gusset comprising two hingably connected gusset panels connects the first side panel and top or bottom panel which gusset is adapted to facilitate movement of the side panel to correlate with the associated shape of a stowed array of articles during the formation of the carton. 
     The carton blank preferably comprises two gussets between the first side panel and the top or bottom panel which gussets cooperate with associated end portions of the first side panel to cause movement thereof during the formation of the carton. Two gussets can connect both side panels to the top panel and two gussets connect both side panels to the bottom panel. 
     The side panel can comprise a series of hingably connected portions, and the hingably connected portions can be separated by curvable portions which provide rounded corners in the completed carton. 
     One of the gusset panels can comprise a tab which protrudes therefrom to facilitate tucking of the gusset inside the carton during formation thereof. Also, one of the gusset panels can comprise means such as an edge which operably abuts an end of the carton to help retain the associated side panel in its formed position in the carton. Preferably, said protruding tab comprises said abutting edge. 
     Another aspect of the invention provides a blank for forming a carton for packaging a plurality of articles comprising a series of hingably interconnected main panels for forming an open ended sleeve capable of receiving said articles, two opposite main panels being similarly non-rectangularly shaped substantially to correlate with the cross-sectional shape of the array of articles in a plane parallel to said two opposite main panels, wherein a gusset comprising two hingably connected gusset panels connects a first main panel and one of the two opposite main panels which gusset is adapted to facilitate movement of the first main panel to correlate with the associated shape of a stowed array of articles during the formation of the carton. 
     The gusset can comprise an associated aperture which facilitates folding of the gusset, and the gusset can comprise means which close the aperture when the carton is formed. Other aspects of the invention relate to a carton and of forming a carton. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: 
     FIG. 1 is a plan view of a carton blank for forming a carton according to a first embodiment of the invention; 
     FIGS. 2 to  6  provide different views of the blank shown in FIG. 1 during the process of forming the carton shown in FIGS. 7 and 8; 
     FIGS. 7 and 8 are perspective views of a formed carton according to the first embodiment of the invention; 
     FIG. 9 is a plan view of a blank for forming a carton according to a second embodiment of the invention; 
     FIGS. 10 to  14  are perspective views of a carton according to the second embodiment of the invention; 
     FIG. 15 is a plan view of a blank for forming a carton according to a third embodiment of the invention; 
     FIGS. 16 to  21  are various perspective views of a carton according to a third embodiment of the invention; 
     FIG. 22 is a plan view of a blank for forming a fourth embodiment of a carton according to the invention; 
     FIGS. 23 to  28  provide views of different stages during the process of forming a carton from the blank shown in FIG. 22; 
     FIG. 29 is a perspective view of a carton formed from the blank shown in FIG. 22; and 
     FIG. 30 is a schematic representation of the method of loading and closing the carton shown in FIG.  29 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The first embodiment of the invention is shown in FIGS. 1 to  8  wherein a carton blank  11  for forming carton  10  shown in FIGS. 7 and 8. The carton is designed to hold a non-rectangular array of articles such as an array comprising rows of  2 ,  3  and  2  articles which has a substantially hexagonal cross-section in the horizontal plane. However, since articles such as cans and bottles are generally cylindrical or at least have curved sides in the case of bottles, a hexagonal array of such articles has curved comers. In order to tightly pack such an array, carton  10  has curvable side panel portions. Carton  10  can hold a single tier of tall articles or a double tier of articles. Of course, multiple tiers can be accommodated simply by adapting the length of its side panels to suit the height of the proposed number of tiers. 
     The blank  11  comprises a base panel  12  which is hingably connected to end tabs  22  and  20  and to side panels  14  and  16  via fold lines  56   a  and  56   b , and gusset panels  40   a ,  40   b ,  40   c  and  40   d  as shown in FIG.  1 . Side panels  14  and  16  each comprises a series of side panel portions  42   a  and  42   b ,  46   a  and  46   b ,  50   a  and  50   b , and  54   a  and  54   b . The side panel portions are separated from adjacent side panel portion by curvable panel portions  44   a  and  44   b ,  48   a  and  48   b , and  52   a  and  52   b . The curvable panel portions comprise a series of crease lines which allow some amount of bending of each of the curvable panel portions in order for the side panels  14  and  16  to be folded around packaged articles in an arcuate manner thereby to fully enclose the sides of the carton. The carton therefore has a cross-section in the horizontal plane which is polygonal, in this case hexagonal, with curved, or rounded, corners. 
     Side panels  14  and  16  are hingably attached to first and second top panels  18  and  20  respectively. The top panels  18  and  20  are hingably connected to respective side panels  14  and  16  by gussets  38   a ,  38   b ,  38   c  and  38   d  and fold lines  64   a  and  64   b . The top panels are of the lap type and can be joined together using adhesive or cooperating locking means such as tabs and apertures, for example. Top panel  18  comprises end tabs  26   b  and  28   b  hingably connected thereto along fold lines  25   c  and  25   d  respectively. Slit features  33   c  and  33   d  are positioned at the fold line between the first top panel  18  and each of the end tabs  26   b  and  28   b  but in other embodiments only one or no such features might be provided. These slit features  33   c  and  33   d  enable bending of the fold line between the side tabs and first top panel when handle  30  is used as described later. Handle  30  is provided in second top panel  20  and comprises a strap having finger tabs  32  foldably joined thereto. Second top panel  20  is foldably connected to end tabs  26   a  and  28   a  along fold lines  25   a  and  25   b  respectively and, in this example, the ends of the handle strap extend into end tabs  26   a  and  28   a  along lateral cuts  33   a  and  33   b . Second top panel  20  also comprises a handle reinforcement panel  36  which, in this example, is hingably connected to the strap of handle  30  along fold lines  34 . 
     Each of the gussets  38   a ,  38   b ,  38   c  and  38   d  can, as shown in FIG. 2, comprises an outermost panel  58  hingably connected to an innermost panel  60 . A cut  62  can be used to separate part of panel  58  from panel  60  and the associated top panel  18  or  20 . Thus cut  62  can usefully define a protrusion  59  from outermost gusset panel  58  which protrusion  59 , or folding means, can be used to tuck the gusset inside the carton and hence help the folding of the sides of the carton. Lower gussets  40   a ,  40   b ,  40   c  and  40   d  could be formed similar to gussets  38  but here each comprises two symmetrical panels which are hingably connected to one another along a fold line  41 . 
     A method of folding blank  11  to form a completed carton  10  as shown in FIGS. 7 and 8, can be seen in FIGS. 2 to  6 . First top panel  18  can be first folded about fold line  64   b  so that it is overlaid on side panel  14 . Reinforcement panel  36  can then be folded about fold line  34  beneath handle strap  30  thereby to provide a two-ply handle and thus strengthen the handle. Side panels  16  and second top panel  20  can then be folded about hinge line  56   a  into the configuration shown in FIG.  3 . The first and second top panels can then be attached to one another for example by gluing at overlapped portions, or using cooperating locking means (not shown) such as locking tabs and apertures. Of course, other panels could be used as overlap panels to enable a tubular sleeve to be formed. 
     The handle edges at cuts or slits  33   a  and  33   b  are thus substantially aligned with slit features  33   c  and  33   d  in first top panel  18  in order to allow parts of the hinge or fold lines  25   a ,  25   b ,  25   c  and  25   d  between the top panels and end tabs  26   a  and  28   a , and  26   b  and  28   b  to move. This enables upward flexing of the handle strap  30  in use by allowing inward movement at the portion of the handle strap adjacent the ends of the carton. To assist in this movement, a pair of lateral creases or fold lines  35   c  and  35   d  can be provided for example in the first top panel  18  as shown in FIG.  2 . In this example both the fold lines  35   c  and  35   d , and associated parts of fold lines  25   c  and  25   d  which extend across the deflectable portion which extends between the end tab and the top panel assist in the inward deflection thereof when handle  30  is used. 
     The folded blank can then be opened to form a sleeve like structure as shown in FIG.  4 . In this configuration, articles such as cans can be loaded into a partially formed carton  1 O through the open ends thereof. After loading the articles, the end tabs  22  and  24  can be folded upwardly whilst end tabs  26   a ,  26   b ,  28   a  and  28   b  can be folded downwardly. The side panel  14  and  16  can then be folded around the articles to close the ends of the carton. For example, gussets  38   a ,  38   b ,  38   c  and  38   d  can be folded into the position under the associated top panel  18  or  20  by pressing inwardly the panel  58  and/or the panel  60  of one or more of the gussets  38 . By folding the gussets  38   a  to  38   d  inwardly, the ends of the side panels  14  and  16  are caused to close about the ends of the carton  10 . Similarly, by folding gussets  40   a  to  40   d  inwardly of the carton  10 , the lower part of side panels  14  and  16  can be caused to rotate to close the ends of the carton. 
     Associated endmost portions of side panels  14  and  16  are thus brought into an overlapping relationship with each other as shown in FIG.  7 . To maintain the carton in its closed configuration, endmost portions  54   a  and  54   b  can be attached to one another, for example by gluing or by cooperating locking means such as locking tabs and apertures. Also, either one or both of the endmost portions  54   a  and  54   b  can be attached to either one or both of end tabs  26   a  and/or  26   b  or end tab  22 . Thus, various overlapping portions can be attached together. Similarly, the opposite end of the carton can be maintained in a closed position so as to form the fully enclosed carton  10  shown in FIGS. 7 and 8. 
     It can be seen that carton  10  is designed to fully and tightly enclose an array of articles by having curvable side panels which wrap tightly around the articles. The carton is made aesthetically pleasing by having suitably shaped top and bottom panels which reflect the non-rectangular shape of the stored array of articles. Of course, other non-rectangular arrays such as triangular, rhombic, rhomboidal, and octagonal arrays for example could be used. 
     A second embodiment of a carton  110  according to the invention is shown in FIGS. 9 to  14 . In this embodiment, features substantially similar to those shown in the first embodiment are labeled using the same two-digit reference numeral prefixed by the numeral  1 . Thus, a first top panel  118  is hingably connected to a side panel  114  which in turn is hingably connected to a base panel  112 . The base panel  112  is connected to a second side panel  116  which is hingably connected to a second top panel  120 . In this example, handle slots  133  are substantially similar to those in the previous embodiment, however, fold lines  135   c  can be provided to define a displaceable portion  131   c  adjacent the fold lines  125   c  and  125   d  between top panel  118  and end panels  126   b  and  128   b  respectively. Alternatively, those lines labeled  135   c  can be cut lines thereby providing an aperture  131   c  at the fold lines between the first top panel  118  and end panels  126   b  and  128   b.    
     In the side panels  114  and  116 , the central curvable portions of the first embodiment are replaced by a central panel portion  148   a  and  148   b  and the other side panel portions can be simply hingably connected by a single fold line. In this embodiment, the side panels are also adapted to wrap around the sides of an array of articles to fully enclose the sides thereof. However, the base panel  112  and carton top panel, formed from panels  118  and  120 , do not comprise overly rounded corners, but each is an irregular octagon. In this example an array of articles with rows of 1, 2, 2 and 1 articles is intended to be placed in the or each tier. The blank  111  shown is adapted to hold two tiers of such arrays of cans for example. 
     The side panels are hingably connected to the associated top panel by gussets  138  which can each comprise a main panel  158  for example hingably connected to the associated side panel  114  or  116  and minor panel  160  hingably connected to both the main gusset panel  158  and the associated top panel  118  or  120 . An interrupted cut  162  can be used to separate part of panel  158  from panel  160  and the associated top panel  118  or  120 . Thus cut  162  can usefully define a protrusion  159  which can be used to tuck the gusset  138  into the position between the associated top panel  118  or  120  and the articles within the carton  110 . In other words, the shape of the gusset panels is designed to assist in the folding of the side panels during the closing of the carton after loading. Also, an edge  157 , here provided on each of the main gusset panels  158 , cooperates in the formed carton with an end panel  126  or  128  to retain the formed shape of the side panels. 
     The side panels  114  and  116  here each comprise removable portions  170   a  and  170   b . These portions can be attached to the carton blank in part at least along a tearable line  174  and by fold lines  153  and  156  or  164  as shown in FIG.  9 . The removable portions  170  can comprise means to assist in the removal of the portion from the carton such as a finger aperture  172 . The finger aperture can be closed by a hingable tab portion until it is used. 
     Carton  110  can be formed by folding blank  111  in a manner substantially similar to that described with reference to the first embodiment. Thus top panel  118  can be folded about fold line  164   b , side panel  116  and top panel  120  can be folded about fold line  156   a  and the top panels attached to one another at overlap portions thereof. A carton sleeve can then be formed and loaded prior folding side panels  114  and  116  round and closing the ends by folding end panels  122 ,  124 ,  126   a ,  128   a ,  126   b  and  128   b  about their associated fold lines. 
     Beneficially, the openable portions  170  enable an article A to be removed from carton  110  without tearing open the entire carton. As shown in FIGS. 11 and 12, openable and closeable portion  170   b  can be opened by breaking the tearable line  174  and opening the panel  170   b  about fold line  153   b . Additionally, a tear line  161   c  can be provided in gusset  138   c  between gusset panels  158   c  and  160   c  (see FIG. 9) to enable openable panel  170   b  to be fully opened. 
     As can be seen in FIG. 12, carton  110  can package two tiers of articles which can be separated by a partition panel  176  for example. In order to gain access to the lower tier of articles, a second openable or removable portion  170   a  can be provided. In order to open openable portion  170   a  it is folded about hinge line  143   a  whilst breaking tearable feature  174  and tearable fold line  141   b  between the panels of gusset  140   b  (see FIG.  9 ). Of course, the gussets could be designed to enable the openable panels to be fully opened without the need of a second tearable feature such as lines  161   c  or  141   b  just described. 
     Additionally, in this example, the gusset panels  138  are folded beneath the associated upper panel by folding gusset panels  158  and  160  relative to one another about fold line  161  so that both portions are superposed beneath the top panel. The main gusset panel  158  can thus lie adjacent a fold line  125  between end panels  126   a ,  126   b ,  128   a  or  128   b  at edge  157  thereof thereby to provide rigidity at this fold line between the side panels and up to the edge of the handle strap as well as acting to retain the shape of the side panels. 
     A third embodiment of a carton according to the invention will now be described in relation to the blank and carton shown in FIGS. 15 to  20 . In this example of the invention, features similar to those of the first two embodiments are labeled using the same last two-digit reference numeral prefixed with the numeral  2 . Thus, a first top panel  218  is hingably connected to a side panel  214  which in turn is hingably connected to a base panel  212 . A second side panel  216  is hingably connected to both base panel  212  and a second top panel  220 . The side panels  214  and  216  are substantially similar to those shown in FIG. 9 as described above, except the openable (and/or removable) portions  270  have a different configuration. In this example, a tearable line  274  extends substantially about three sides of the rectangular panel forming removable portion  270 . The openable portion  270   a  and  270   b  are hingably connected on a fourth side along fold lines  239   b  and  237   c  respectively. Each of these fold lines connects the openable portions  270   a  and  270   b  to an associated gusset panel namely  240   b  and  238   c  respectively in this example. A finger aperture  272  can be provided and this can be covered by a foldable tab  271 . 
     Openable portion  270   b  is foldable about fold line  237   c  in the completed carton as shown in FIG.  17 . The portion  270   b  can be removed by tearing along fold line  261   c  as shown in FIG. 18 thereby to leave a carton wherein the articles A in an upper tier are removable as shown in FIG.  19 . Similarly, lower openable portion  270   a  is openable by folding about fold line  239   b . Also, the portion  270   a  can be removed entirely by tearing along fold line  241   b  for example. 
     In this example the carton  210  is adapted to hold two tiers of articles, wherein each tier comprises an array of 1, 2, 2 and 1 rows of articles. Of course, different numbers of rows of different numbers of articles could be packaged and indeed different numbers of tiers can be housed by suitably adapting the blank described here. 
     A fourth embodiment of a blank  311  and of a carton  310  formed therefrom as shown in FIGS. 22 to  30 . The formed carton  31  shown in FIG. 29 has a generally octagonal cross-section in the horizontal plane and is designed to accommodate a single tier of articles such as bottles in an array of 3, 4, 4, and 3 articles per row. 
     Blank  311  comprises a top panel  320  which is hingably connected to side panel  316  along fold line  364   a . In turn, the side panel  316  is hingably connected to base panel  312  having an octagonal shape. The base panel  312  is connected to a second side panel  314  along a fold line  356   b . In this embodiment, instead of providing overlapping top panels to form the blank into a tubular, sleeve like structure, a tab  315  is provided. In this embodiment tab  315  which is hingably connected to the top panel  320  along a fold line  364   b  can be attached to an upper portion of side panel  314  for example by gluing or by using cooperating locking means such as locking tabs and apertures. 
     Blank  311  comprises a handle  330  having finger tabs  332  in the top panel  320  and a handle reinforcing strap  336 , which here is hingably connected to the end panels  326  and  328  which are hingably connected to the top panel  320 . Additionally, diverging crease lines can be formed in the top panel  320  to provide a stress-relieving feature  380  for when the handle is used. In this embodiment, openable features  370  are provided in the top panel  320 . 
     The openable features  370  abut the aperture defined by the finger tabs  332  which form part of the handle  330  and have lateral tearable lines similar to lines  274  and  174  shown in the second and third embodiments described herein. Four gussets  338  are provided between the top panel  320  and effectively the side panels of the carton when tab  315  and side panel  314  are attached. The gussets  338  are equivalent in this example and with reference to gusset  338   a  it can be seen that they comprise a main panel  358   a  which is hingably connected to side panel  316 . The main panel  358   a  is hingably connected to a minor panel  360   a  which in turn is hingably connected to top panel  320 . The main gusset panel  358   a  comprises a protruding tab  359   a  which can be used to close the carton and to retain the associated side wall in a curved formation due to cooperation between the edge  357   a  of tab  359   a  and end panel  328  for example. This cooperation is more apparent with reference to the later drawings. Also, the gusset panel  358  can be positioned between an associated, e.g. cornermost, article top such as a bottle cap and the top panel  320 . This can help prevent any aperture opening in the top of the carton when formed in spite of the aperture  363  formed adjacent the gusset. 
     The side walls  316  and  314  are symmetrical and comprise a main central panel having a medial fold line  385   a  and  385   b  respectively which enable both side panels to be folded substantially in half. This is beneficial in enabling the partially formed carton shown in FIG. 25 to be flat packed ready for erection into the sleeve like structure shown in FIG. 26 which is ready for loading. The medial fold lines  385   a  and  385   b  extend into side panel portions  346   a ,  350   a ,  346   b  and  350   b . Additionally, a gusset  386  is provided adjacent each fold line  385  in the lateral portions of the side panels. These gussets  386  facilitate better wrapping of the sides and ends of loaded articles and the formation of a sloping upper portion of the side panels which can be seen with reference to FIGS. 27 to  29 . To this end fold lines  323   a  and  323   b  are also provided in lower end panel  324  and  322  respectively. In order to form the sloping upper portion it is apparent that top panel  320  should be a smaller octagon than base panel  312 . Additionally, in common with the other embodiments, gussets  340  can be provided between base panels  312  and the side panel. 
     In order to form carton  310  the reinforcing strip  336  is folded about fold line  334  into position shown in FIG.  23 . Thus, apertures  382  in strip  336  are aligned with fold lines  325   a  and  325   b  thereby minimizing any restriction in the folding of the upper end panels  328  and  326  about fold line  325   a  and  325   b  when closing the ends of a loaded carton. Next, the top panel  320  and upper portion of side panel  316  are folded about fold line  385   a  into the position shown in FIG.  24 . The upper portion of side panel  314  is then folded about fold line  385   b  so that it abuts tab  315  and can be attached thereto for example by gluing, to form the flat structure shown in FIG.  25 . Conveniently, blanks  311  can be stored in this flat arrangement and transported to packaging machinery ready to be loaded into suitable hoppers such as hopper H shown schematically in FIG.  30 . 
     To load a carton the structure shown in FIG. 25 is first expanded into the sleeve like structure as shown in FIG.  26 . This is also shown in the upstream part of the packaging process shown in FIG. 30, wherein it is apparent that the carton is moved downstream along the flow direction indicated by arrow F. In this schematic drawing it can be seen that at stage A, the infeed rows of articles are separated into the desired formation of two rows on each of the open ends of the carton comprising an innermost row of four articles and an adjacent outermost row of three articles. The outer row is displaced slightly with respect to the inner row so that the rows of articles are nested thereby to form a relatively tightly packed configuration. That is, an article in the outer row abuts two articles in the inner row. This is not true of the abutment of the two inner rows after they have been loaded into the carton during the phase indicated by section B of FIG.  30 . The adjacent innermost rows of four articles abut one another so that only a single article is abutted in the adjacent innermost row. However, for different sizes or shapes of cartons it would of course be possible to provide a different structure of abutment of the articles within the carton. 
     After loading a carton  320 , the gussets  338  and  340  are tucked inwardly in zone C of the flow path shown in FIG.  30 . Main gusset panel  358   c  is tucked inwardly to a position beneath top panel  320 . Also, the gussets  340  are tucked upwardly. This tucking action of the gussets causes a bending of the side panels towards the partially closed structure shown in FIG.  27 . The endmost parts of the side panels  350   a  and  350   b  can then be drawn further round to the ends of the carton as shown in zone D of FIG.  30 . This causes further curvature of side panels  314  and  316  which thereby contour the sides of the adjacent articles and reflect the shape of three sides of the octagonal base panel  312  and top panel  320 . Additionally, the upper portions of the side panels  314  and  316  bevel in, or are inclined, thereby to contour the shoulders of the bottles retained within a carton. 
     The upper and lower end panels  322 ,  324 ,  328  and  326  can then be folded about the associated fold line to the top or lower panel as shown in FIG.  28 . The associated upper and lower end panels such as panels  328  and  322  can then be attached to one another for example by gluing. Alternatively, cooperating locking means such as locking tabs and apertures might be provided. Also, the end panels can be attached to the end panels  346   a ,  346   b ,  350   a  and  350   b . For example, if an adhesive such as glue is used then the finished carton shown in FIG. 29 can be pressed in zone E of FIG. 30 to ensure the panels remain closed.