Abstract:
A carton and carton blank for forming a carton of the top gripping type for accommodating a plurality of containers, for example bottles, which carton is tubular in structure and comprises a first panel having a plurality of apertures, each of which has at least one foldable retention tab which operatively engages the underside of the radially protruding part of a container present in the aperture wherein a brace tab is connected to one of said retention tabs and is disposed between a pair of adjacent containers to minimize relative movement between those containers and wherein a free edge of said brace tab operatively engages the underside of the radially protruding part of one of said adjacent containers.

Description:
BACKGROUND OF THE INVENTION 
     The invention relates to a carton produced for packaging a plurality of articles, for example bottles. More particularly the invention relates to a carton of the top gripping type which attaches to the tops of the articles thereby securing the articles in an array. 
     It is known to provide top gripping cartons which comprise so called sunburst apertures having a series of circumferencially arranged tabs which enable the bottle top to pass through the apertures which tabs engage on the underside of a bottle top or on the flange of a bottle neck to prevent the removal of the bottle from the aperture. A problem arises when such sunburst type apertures are used for bottles, in particular the location in which the tab engages the underside of the bottle top is high up on the bottle neck. This creates a carton that is unstable. Further, the tabs are weakened by the unstable nature of the bottles within the carton so reducing its effectiveness. 
     A further problem is that a top gripping carton needs to be of sufficient strength to support the bottle. A rigid structure would address this problem but produces its own difficulties. In particular, a top panel and/or base panel does not provide requisite rigidity and sufficient strength to support the bottle. 
     Known cartons of this type are disclosed in EP0541334 A1. This patent specification discloses keel construction suitable for retaining and/or separating articles. However, the keels are somewhat complex to set up from a collapsed form in the carton blank. Several different embodiments of keels are shown and described however, each keel acts to separate two articles in adjacent rows is formed from at least two separate tabs which are struck from the base of the carton which panels are required to be interlocked for example at a co- operating tab and aperture in order to form an erected keel. In some embodiments the base of the carton is formed from two overlapping base panels which are also required to be interlocked and accordingly the formation of the carton and keel structure is fairly complex. 
     The invention seeks to avoid or at least mitigate these and other problems of the prior art. Positional support is provided to maintain top and base panels in a spaced arrangement while additional strength is provided by multi layering the panels. Therefore the board can be reduced in thickness without reducing the strength needed to hold the bottle. 
     SUMMARY OF THE INVENTION 
     Accordingly, in one form of the invention there is provided a carton of the top gripping type for accommodating a plurality of containers, for example bottles, which carton is tubular in structure and comprises a first panel having a plurality of apertures each of which has at least one foldable retention tab which operatively engages the underside of a radially protruding part of a container present in the aperture wherein a brace tab is connected to one of said retention tabs and is disposed between a pair of adjacent containers to minimize relative movement between those containers and wherein a free end edge of said brace tab operatively engages the underside of the radially protruding part of one of said adjacent containers. 
     According to one optional feature each aperture may be defined by a pair of retention tabs struck from said first panel. The retention tabs of the pair are disposed in positions where they are opposed to each other. 
     According to another optional feature said brace tab may be placed in a substantially parallel and spaced relationship with the said first panel. 
     Another aspect of the invention provides a unitary blank for forming a carton of the top gripping type which comprises a first panel having a plurality of apertures each of which has at least one foldable retention tab around each aperture and foldable to stand out of the general plane thereof and a brace tab struck from one of the apertures and hingably connected to one of said retention tabs, the brace tab being foldable out of the plane of the retention tab so that the end edge of the brace tab abuts a retention tab from an adjacent aperture when said carton is set up. 
     A further aspect of the invention provides a keel structure for separating two adjacent articles and/or retaining said articles in a carton, comprising first and second retention tabs hingably connected to a panel of the carton, said first and second retention tabs respectively engaging the underside of the radially protruding parts of the adjacent articles, wherein said first retention tab comprises a brace tab which extends between the first and second retention tabs to separate and/or retain said adjacent articles. 
     Preferably, the keel structure resiliently separates two adjacent articles. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the drawings: 
     FIG. 1 is a plan view of a carton blank for forming a carton according to the invention; 
     FIG. 2 is a schematic perspective view of a carton formed from a carton blank shown in FIG. 1 according to the invention; and 
     FIGS. 3 and 4 are a schematic perspective representations of two stages in the process of forming a keel structure and part of a carton according to the invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to the drawings, and in particular FIG. 1 thereof, there is shown a carton blank  10  for forming a top gripping carton made from paper board or similar foldable sheet material. The blank  10  comprises glue flap  12 , first side panel  14 , base panel  16 , second side panel  18 , and top panel  20 , hingably connected one to the next along fold lines  22 ,  24 ,  26  and  28  respectively. 
     As illustrated in FIG. 1, base panel  16  is formed with two pairs  30  and  32  of retention tabs being struck from base panel  16  adjacent to fold line  24  and laterally spaced intermediate the side edges of base panel  16 . Each pair  30  and  32  of retention tabs are struck from base panel  16  to define the pair of article receiving apertures  34  illustrated partially in FIG.  2 . 
     Turning in detail to the configuration of one pair  30  of retention tabs, there comprises retention tab  36  struck from and hingably connected to first side panel  14  along fold line  24 . Tab  36  extends inwardly of base panel  16  to its distal edge  38 . Tab  36  comprises opposed side edges  40  and  42  which arcuately curve outwardly and diverge from each other toward the distal edge  38  such that the length of the distal edge  38  is greater than the fold line connecting tab  36  to first side panel  14 . 
     A second retention tab  44  is hingably connected to base panel  16  along fold line  46  and is positioned in a central region of base panel  16 . In this embodiment, tab  44  is oppositely disposed to tab  36  and extends into aperture  34 . In this embodiment, distal edge  48  of tab  44  is juxtaposed to the distal edge  38  of tab  36 . Likewise, the side edges  50 ,  52  of tab  44  arcuately curve outwardly and diverge from each other towards distal edge  48  to provide the distal edge  48  having a greater length than the fold line  46 . The curved side edges  40 ,  42 ;  50 ,  52  of tabs  36  and  44  respectively define a substantially circular aperture  34  shown in FIG. 2, when the retention tabs  36 ,  44  are in a set up condition. 
     A brace tab  54  is hingably connected to the distal edge  48  of tab  44  along fold line  56 . Tab  54  is struck from and extends into retention tab  36 . In this embodiment, brace tab  54  is substantially trapezoidal in shape. 
     Likewise, the second pair  32  of retention tabs is substantially identical in size and configuration to the first pair  30  of retention tabs described above and are not therefore described in any greater detail. 
     Base panel  16  is also formed with two further pairs  60  and  62  of retention tabs. As illustrated in FIG. 1, the further pairs  60  and  62  of retention tabs are struck from base panel  16  adjacent to fold line  26  and laterally spaced intermediate the side edges of base panel  16 . Each pair  60  and  62  of retention tabs are struck from base panel  16  to define the pair of article receiving apertures  64 , illustrated partially in FIG.  2 . 
     Turning in detail to the configuration of one pair  60  of retention tabs, there comprises retention tab  66  struck from and hingably connected to second side panel  18  along fold line  26 . Tab  66  extends inwardly of base panel  16  to its distal edge  68 . Tab  66  comprises opposed side edges  70  and  72  which arcuately curve outwardly and diverge from each other toward the distal edge  68  such that the length of the distal edge  68  is greater than the fold line connecting tab  66  to second side panel  18 . 
     A second retention tab  74  is hingably connected to base panel  16  along fold line  76  and is positioned in a central region of base panel  16 . In this embodiment, fold line  76  is in a parallel and spaced relationship with fold line  46  such that retention tabs  44  and  74  are aligned. It is envisaged that such alignment is not necessary in all embodiments. Tab  74  is oppositely disposed to tab  66  and extends into aperture  60 . In this embodiment, distal edge  78  is juxtaposed to the distal edge  68  of tab  66 . Likewise, the side edges  80 ,  82  of tab  74  arcuately curve outwardly and diverge from each other towards distal edge  78  to provide the distal edge  78  having a greater length than the fold line  76 . The curved side edges  70 ,  72 ;  80 ,  82  of tabs  66  and  74  respectively define a substantially circular aperture  64  shown in FIG. 2, when the tabs  66 ,  74  are in a set up condition. 
     The second pair  62  of retention tabs is substantially identical in configuration to the first pair  60  of retention tabs described above and are not therefore described in any greater detail. 
     It is envisaged that suitable handle means generally known may be provided. 
     Turning to the construction of the carton as illustrated in FIGS. 2,  3  and  4 , the blank  10  requires a series of sequential folding and gluing operations which can be performed in a straight line machine so that the carton is not required to be rotated or inverted to complete its construction. The folding process is not limited to that described below and can be altered according to particular manufacturing requirements. 
     Thus, bottles B are grouped together in two rows of two bottles b 1 , b 2  and the blank  10  is introduced to the group from above by relative vertical movement between the bottles and the blank  10 , preferably during forward feed movement well known in the art. It is envisaged that blank  10  can be adapted to accommodate any number of articles in any number of rows. 
     FIGS. 3 and 4 show only a section of the carton substantially as hereinbefore described and illustrated in FIGS. 1 and 2, and are included to illustrate the folding process. It is envisaged that the shape of retention tabs and brace tabs is not limited to the type illustrated in FIGS. 1 and 2. Thus, each pair  30  and  60  of retention tabs, shown in FIGS. 3 and 4 are folded along their respective fold lines  24 ,  46 ; 26 ,  76  and out of their general plane with respect to base panel  16  to create article receiving apertures  34 ,  64 , shown in FIG.  2 . In this embodiment, tabs  44  and  74  are moved inwardly and upwardly in the direction of arrow ‘X’ and ‘Y’ respectively and are placed in a substantially upright position, while tabs  36  and  66  are moved outwardly and upwardly and are placed in a substantially upright position. The angle subtended between retention tabs for example  36  or  44  and the associated main carton panel such as base panel  16  is not crucial but is preferably in the region of 60-90°, but of course can be adapted to suit the shape of the packaged article. 
     As shown in FIG. 3, the bottles b 1  and b 2  are moved into their respective apertures  34  and  64  until the distal edges  38 ,;  68 , 78  of the retention tabs  36 ,; 66 , 74  respectively come into contact with and are engaged with the underside of the respective protruding portion P 1  and P 2  of the bottles B associated within each of the apertures  34 , 64 . Optionally, the edge of each article receiving aperture  34 , 64  is in contact with a neck portion of each of the respective bottles B to provide additional support. 
     Brace tab  54  is folded backwardly about fold line  56  and placed in an angular relationship with retention tab  44 . Thus, distal edge  48  of tab  44  is engaged with the underside of protruding portion P 1  of bottle B 1 . Brace tab  54  extends towards retention tab  74  struck from the opposite aperture  64  and engages the protruding portion P 2  of an adjacent bottle b 2 . Preferably, brace tab  54  is abuts retention tab  74  and serves as a brace between the retention tabs  44  and  74 , as shown in FIG.  4 . 
     Thereafter, side panel  14  is folded about fold line  24  into a substantially perpendicular relationship with base panel  16  and glue flap  12  is folded about fold line  22  such that glue flap  12  is in a substantially parallel and spaced relationship with base panel  16 . Likewise side panel  18  is folded about fold line  26  into a substantially perpendicular relationship with base panel  16  and top panel  20  is folded about fold line  28  such that the free end portion of top panel  20  is placed in a face to face contacting relationship with glue flap  12 . Top panel  20  and glue flap  12  are secured together by glue or other means known in the art. Thus the carton is in a set up condition as shown in FIG.  4 . 
     In use, the brace tabs  54 , provide a horizontal brace to better maintain the bottles in their upright position. 
     The present invention and its preferred embodiments relate to an article carrier which is shaped to provide satisfactory strength to hold bottles securely but with a degree of flexibility so that the load transferred through the retention tabs is absorbed by the carrier. The shape of the blank minimizes the amount of paper that would be required and the carrier can be applied to an array of bottles by hand or automatic machinery. It is anticipated that the invention can be applied to a variety of carrier and not limited to those of the top gripping type.