Abstract:
A carton and a blank for forming a carton for holding a plurality of articles, for example bottles, comprising a collapsible tubular corner post formed from an extension of a carton side wall. The corner post is adapted to move from a flat collapsed condition when extending outwardly of the carton to be automatically erected by folding the corner post inwardly.

Description:
This is a continuation of international application No. PCT/US01/28504, filed Sep. 15, 2001, which is hereby incorporated by reference. 

   BACKGROUND OF THE INVENTION 
   The invention relates to a carton and to a blank for forming a carton for carrying a plurality of articles, for example flexible pouches or bottles, and one or more beam structures for improving the rigidity of the carton. It may further comprise a tear-open flap that can be reclosed. 
   The use of beam structures is known; for example, in U.S. Pat. No. 5,673,840 there is shown a corner post structure for improving the rigidity of the carton. The invention is particularly useful where it is desirable for cartons containing articles to be enclosed to protect each article, for example information discs or foodstuffs. 
   One example of reclosable sleeves formed from one or more blanks of cardboard is found in U.S. Pat. No. 3,078,030 which illustrates a carton having an integral hinged top that it reclosable. The top is provided by a front cover panel and a spacer panel secured to one side of the front cover panel to interfit with a mating upper portion of the front panel of a box. Fastening means is formed from a detached double layer portion of the front panel. However, the detached portion is attached to the inside surface of the cover flap, resulting in a stepped non-flat front surface. 
   In U.S. Pat. No. 3,894,680 there is provided a dispensing spout in a carton box adapted to accommodate powdery materials, for example detergents, which spout is adapted to keep closed after it has been cut out. The fastening means is formed from a detached triple layer portion of the front panel but it does not define a pocket to retain the spout. 
   Further, supporting the weak parts of a carton, such as corners and the like, is well known. For example, U.S. Pat. No. 5,673,840 illustrates a corner post structure. However, in automated packaging, it is necessary to load articles into the carton at high speeds; therefore, it is undesirable to have a complicated arrangement for forming a corner post structure. 
   SUMMARY OF THE INVENTION 
   The present invention seeks to overcome or at least mitigate the problems of the prior art. 
   One aspect of the invention provides a carton for holding a plurality of articles, for example bottles, comprising a collapsible tubular corner post formed from an extension of a carton side wall, which corner post is adapted to move from a flap collapsed condition when extending outwardly of the carton to be automatically erected by folding the corner post inwardly. 
   One advantage of this arrangement is that the blank and corner post can be supplied to the end user in a flat collapsed condition. It can then be automatically deployed by automatic packaging machinery by a simple folding process. Beneficially, the amount of board for the corner post can be reduced and standard equipment to secure the end panels can be used. 
   Preferably, the corner post may have a triangular cross-section to serve as a rigid structure wherein the corner post has a longitudinally extending fold line to allow the corner post to be folded flat only outwardly of the carton. More preferably, the corner post may comprise an end panel, a bracing panel and a securing panel hingedly connected together in series, and the securing panel is secured to the carton side wall. Optionally, the longitudinally extending fold line may be formed in the end panel. 
   According to an optional feature of this aspect of the invention the end panel may be adapted to secure an end flap of the carton to close the carton. 
   A second aspect of the invention provides a carton for holding a plurality of articles, for example bottles, which carton comprises a reclosable tear open flap formed from a first carton wall and a wall end-reinforcing member hinged to the first carton wall. The reinforcing member is affixed at least in part to the inside surface of the first carton wall so that the reinforcing member underlies the first carton wall along at least a part of the tear line. Optionally the reinforcing member extends above the tear line to provide upon breaking of the tear line an engaging element for retaining the flap in a reclosed position. 
   A third aspect of the invention provides a carton for holding a plurality of articles, for example bottles, which carton comprises a reclosable tear open flap including a first panel formed from a first carton wall and an engaging panel affixed at least in part to the inside surface of the first carton wall. The engaging panel extends above the tear line to provide upon breaking of the tear line an engaging element for retaining the flap in a reclosed position. 
   According to an optional feature of the third aspect of the invention, the engaging panel is provided by a reinforcing member hinged to one of the panels adjacent the first carton wall panel. Preferably, the reinforcing member underlies the first carton wall at the corner with a second carton wall, thereby to reinforce the corner. 
   According to another optional feature of the second or third aspect of the invention, the tear open flap comprises a second panel hingedly connected to the first panel. 
   Preferably, the tear open flap further comprises a pull tab. 
   More preferably, the first carton wall is provided with a securing tab hingedly connected thereto, and a portion of the tear open flap or, as the case may be, the pull tab, is adapted to be placed intermediate the first carton wall and the securing tab to be retained therewith. 
   A fourth aspect of the invention provides a blank for forming a carton for holding a plurality of articles, for example bottles, which carton comprises a reclosable tear open flap formed from a first carton wall and a wall end-reinforcing member hinged to the first carton wall, wherein the reinforcing member is affixed at least in part to the inside surface of the first carton wall so that the reinforcing member underlies the first carton wall along at least a part of the tear line. 
   Preferably, the corner post may have a longitudinally extending fold line to allow the corner post to be folded flat only outwardly of the carton. More preferably, the longitudinally extending fold line may be formed in the end panel. 
   A fifth aspect of the invention provides a blank for forming a carton for holding a plurality of articles, for example bottles, comprising a collapsible tubular corner post formed from an extension of a carton side wall, wherein the corner post comprises an end panel, a bracing panel and a securing panel hingedly connected together in series, wherein said securing panel is adapted to be secured to said carton side wall. 
   Optionally, the corner post has a longitudinally extending fold line to allow the corner post to be folded flat only outwardly of the carton. Preferably, the longitudinally extending fold line is formed in said end panel. 
   A sixth aspect of the invention provides a blank for forming a carton for holding a plurality of articles, for example bottles, which carton comprises a reclosable tear open flap including a first panel formed from a first carton wall and an engaging panel affixed at least in part to the inside surface of the first carton wall wherein the reinforcing member extends above the tear line to provide upon breaking of the tear line an engaging element for retaining the flap in a reclosed position, when the carton is in a set up condition. Optionally, the tear open flap further comprises a pull tab. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Exemplary embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings in which: 
       FIG. 1  illustrates the blank for forming the carton according to a first embodiment of the invention; 
       FIGS. 2 and 3  illustrate the construction of the corner support structure from the blank shown in  FIG. 1 ; 
       FIGS. 4 and 5  illustrate the construction of the carton from the blank shown in  FIG. 1 ; 
       FIG. 6  shows the carton from the blank shown in  FIG. 1  in an erected condition; 
       FIGS. 7 and 8  show the carton of  FIG. 7  with the reclosable tear open flap in open and closed positions; 
       FIG. 9  illustrates a cross-section through B 1 -B 2  of the carton in  FIG. 6 ; 
       FIG. 10  illustrates the blank for forming a carton according to a second embodiment of the invention; 
       FIG. 11  shows the carton formed from the blank of  FIG. 10  in an erected condition with the reclosable tear open flap in closed position; and 
       FIG. 12  illustrates a cross-section through B 3 -B 4  of the carton in FIG.  11 . 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Referring to the drawings and in particular,  FIG. 1 , there is shown an embodiment of a blank for forming a carton made from paperboard or similar foldable sheet material. In the embodiment described below, the carton is a “fully-enclosed” type, although it will be recognised that the invention could be applied to a “wraparound” type carton or “basket-type” carton or other carton where it is required to provide a support structure at the corners of the carton. 
   The blank  10  comprises a plurality of panels for forming an enclosed carton. Turning to the embodiment shown in  FIG. 1 , there comprises first side wall panel  12 , a top panel  14 , a second side wall panel  16  and bottom panel  18  hingedly connected one to the next along fold lines  20 ,  22  and  24  respectively. 
   The ends of the carton are constructed by one or more end flaps or panels. In this embodiment, end panels  30  and  42  are hingedly connected to the opposing ends of top wall panel  14  along fold lines  32  and  44  respectively. A second pair of end panels  34 ,  38  is provided along opposing end edges of bottom panel  18  and hingedly connected thereto along fold lines  36  and  40  respectively. 
   Securing means are provided for securing together the first side wall panel  12  and bottom panel  18 . In this embodiment, securing means are provided by a securing flap  26  hingedly connected to first side wall panel  12  along fold line  28 . 
   There may further comprise an access structure to provide access to the interior of the carton. The access structure comprises a reclosable tear open flap  50  formed from one of the carton wall panels. In this embodiment the flap comprises an upper access panel  53  struck from the top panel  14  and frangibly connected thereto along frangible lines  52  and  54  respectively. Upper access panel  53  is hingedly connected to the second side wall panel along fold line  22 . Preferably, there further comprises a side access panel  51  from the first side wall panel  12  and frangibly connected thereto along frangible fold lines  55  and  56  respectively. It will be seen from  FIG. 1  that frangible lines  55  and  56  converge to a pull tab  58 . Optionally, there further comprises a securing tab  60  hingedly connected to the first side wall panel along fold line  61 . The opening of the access structure  50  will be described in more detail below. 
   According to one aspect of the invention there comprise one or more beam structures formed internally of the carton. The beam structures are positioned intermediate the top and bottom panels of the carton to improve the rigidity of the carton when it is subjected to vertical compression. In this embodiment there are four corner posts  70   a,    70   b,    70   c  and  70   d.  Each corner post is substantially the same and therefore only the first beam structure  70   a  is described in any further detail. 
   In the embodiment shown in  FIG. 1 , the corner post  70   a  comprises securing panel  74   a  and bracing panel  76   a  and an inner end panel  80   a  hingedly connected one to the next along fold lines  82   a,    84   a.  The corner post  70   a  is hingedly connected to the first side wall panel along fold line  72   a.  In one class of embodiments, the fold line  82   a  is a shallow arcuate shape to assist in flexing the panels in the vertical plane, although in other embodiments it is linear or can be dispensed with. There may further comprise a flexing panel  78   a  intermediate bracing panel  76   a  and inner end panel  80   a  along fold lines  84   a  and  86   a  respectively. In use, fold line  86   a  is used to place the corner post in a flat collapsed condition. 
   It is envisaged that the panels for forming the corner post are not limited to the shape illustrated in FIG.  1  and indeed could be replaced by other means to allow a beam to juxtapose the top and bottom panels. For example, bracing panel  76  could be arcuate in cross-section to better receive and retain the adjacent article. 
   Turning to the construction of the carton from the carton blank as illustrated in  FIG. 1 , each blank requires a series of sequential folding and gluing operations which are preferably performed in a straight line machine, so that the carton and blank are 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. 
   Turning to the construction of the corner structures from the blank  10 , reference is made to  FIGS. 2 and 3 . The panels for forming each corner post structure  70   a,    70   b,    70   c,    70   d  are folded inwardly in directions W 1 , W, X 1  and X along fold lines  86   a,    86   b,    86   c,    86   d  to be secured to the respective one of the first or second side wall panels  12 ,  16 . In this embodiment, securing panel  74  is glued to the respective adjacent side wall panel by a strip of glue G (FIG.  2 ). 
   Thereafter, the first side wall panel  12  and bottom wall panel  18  are secured together, whereby, in this embodiment, securing flap  26  is secured to bottom panel  18  by glue or other suitable means known in the art. Thus, the carton is in a flat collapsed position ready to be supplied to an end user for loading with articles. 
   In order to erect the carton it is constructed by folding top panel  14 , first side wall panel  12 , bottom panel  18  and second side wall panel  16  out of alignment with each other along fold lines  28 ,  20 ,  22  and  24  respectively so as to form a tubular structure as shown in FIG.  4 . 
   The carton is at an intermediate stage of construction whereby the articles are inserted into the carton C from one of the ends. It will be seen from  FIG. 4 , that end panels  30  and  34  are preferably folded outwardly along fold lines  32  and  36  respectively to guide the articles into the carton. Preferably, the opposing end wall is formed prior to receiving the articles, whereby corner post structures  70   b  and  70   d  are formed in the manner described below and end wall panels  38  and  42  are folded inwardly along the respective fold lines  40  and  44 , to be secured together by glue or other suitable means known in the art. 
   Once the articles have been loaded into the carton, the corner post structures  70   a  and  70   c  are then formed. 
   In order to form the corner post structure  70   a,  inner end panel  80   a  is folded inwardly in direction Y along fold line  72   a.  This action causes bracing panel  76   a  and intermediate panels  78   a  to be folded out of alignment with respect to securing panel  74   a  along fold lines  82   a,    84   a  and  86   a  respectively to automatically deploy the corner post within the carton. In this embodiment the corner post has a substantially triangular cross-section viewed in more detail in FIG.  9 . In one class of embodiments, the purpose of intermediate panel  78   a  is to provide a degree of resilience for the bracing panel  76   a  where for example it comes into abutment with the outermost article. However, in this embodiment, it is adapted to be placed in a co-linear arrangement with inner end panel  80   a.    
   The opposing corner post structure  70   c  and the other structures  70   b,    70   d  are formed in substantially the same manner as beam structure  70   a  and they are therefore not described in any greater detail hereinafter. Thus the carton is at the stage illustrated in FIG.  4 . 
   In order to complete construction of the carton C, the end wall panels are secured together. To this end, glue G is applied to the inner faces of end wall panels  30  and  34  and then folded inwardly along fold lines  32  and  36  respectively and into abutment to be secured together. Preferably, the end wall panels  30  and  34  are also secured to the inner end panels  80   a  and  80   c  of their respective corner post structures  70   a  and  70   c  to provide additional securing points. 
   In alternative embodiments glue may be applied to different areas of the blank such as where corner support structure are used. Thus the carton is in a set up condition and fully loaded with articles ready to be supplied to the user, as shown in FIG.  6 . 
   In order to gain access to the interior of the carton, the access structure can be opened whereby securing tab  60  is pushed inwardly to reveal the pull tab  58 . Thereafter, the pull tab  58  is pulled in an outward direction which causes the side access panel  51  to be separated from the first side wall panel  12  along frangible lines  55  and  56 . By continued pulling on pull tab  58  in an upward direction, the upper access panel  53  is separated from top wall panel  14  along fold lines  52  and  54  respectively. The access structure is folded backwards along fold line  22  to reveal the contents of the carton, as shown in FIG.  7 . 
   To reclose the access structure, there are provided opposing tabs  75   a  and  75   b,  which are secured to the inner face of one of the top or side wall panels. In this embodiment, tabs  75   a  and  75   b  are provided by the securing panels  74   a  and  74   b.  It is envisaged, however, that these tabs could be applied independently of the beam structure and, in fact, could be applied to cartons where no beam structures are provided. The tabs  75   a  and  75   b  are adapted so that the side access panel  51  can be placed within the carton such that the outer face of access panel  51  abuts the inner surface of insert  75   a  and  75   b  shown in FIG.  8 . In order to engage the side access panel  51 , pull tab  58  or—as the case may be—part of access panel  51 , is placed securing tab  60  and side wall panel  12 , thereby providing a pincer arrangement to secure the pull tab  58  (or access panel  51 ) thereto and to provide a reclosable access structure shown in FIG.  8 . 
   Turning to a second embodiment of the present invention in  FIGS. 10  to  12 , there is shown a blank  110  comprising a plurality of panels for forming an enclosed carton. With reference to the embodiment shown in  FIG. 10 , the blank comprises first side wall panel  112 , a top panel  114 , a second side wall panel  116  and bottom panel  118  hingedly connected one to the next along fold lines  120 ,  122  and  124  respectively. 
   The ends of the carton are constructed by one or more end flaps or panels. In this embodiment, end panels  130  and  142  are hingedly connected to the opposing ends of top wall panel  114  along fold lines  132  and  144  respectively. A second pair of end panels  134 ,  138  is provided along opposing end edges of bottom panel  118  and hingedly connected thereto along fold lines  136  and  140  respectively. 
   Securing means are provided for securing together the first side wall panel  112  and bottom panel  118 . In this embodiment it is provided by a securing flap  126  hingedly connected to first side wall panel  112  along fold line  128 . 
   There further comprises an access structure that provides access to the interior of the carton. The access structure is similar to the first embodiment and comprises a reclosable tear open flap  150  formed from one of the carton wall panels. In this embodiment the flap comprises an upper access panel  153  struck from top panel  114  and frangibly connected thereto along frangible lines  152  and  154  respectively. Upper access panel  153  is hingedly connected to end wall panel  130  along fold line  132 . 
   Preferably, there further comprises a side access panel  151  struck from the first end wall panel  142  and frangibly connected thereto along frangible fold lines  155  and  156  respectively. It will be seen from  FIG. 10  that frangible lines  155  and  156  converge to a pull tab  158 . Optionally, there further comprises a securing tab  160  hingedly connected to the end wall panel  142  along fold line  161 . The opening of the access structure  150  will be described in more detail below. 
   There further comprises one or more corner support structures formed internally of the carton. In the first embodiment, the support structures are positioned intermediate the top and bottom panels of the carton to improve the rigidity of the carton at the weaker parts, for example the corners of the carton. 
   In the second embodiment there are four corner support structures  170   a,    170   b,    170   c  and  170   d.  Each corner support is substantially the same and therefore only the first corner support structure  170   a  is described in any further detail. In the embodiment shown in  FIG. 10 , the corner support  170   a  comprises securing panel  174   a  and inner support panel  176   a  and an outer support panel  180   a  hingedly connected one to the next along fold lines  184   a,    186   a.  The corner support  170   a  is hingedly connected to first side wall panel  112  along fold line  172   a.    
   It is envisaged that the panels for forming the corner structure are not limited to the shape illustrated in  FIG. 10 , and could indeed be replaced by other means to allow the structure to juxtapose the top and bottom panels. 
   Turning to the construction of the carton from the carton blank as illustrated in  FIG. 10 , again each blank requires a series of sequential folding and gluing operations which are preferably performed in a straight line machine, so that the carton and/or blank are 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. 
   The panels for forming each corner support structure  170   a,    170   b,    170   c,    170   d  are first folded inwardly along fold line  186   a,    186   b,    186   c,    186   d  to be secured to the respective one of the first or second side wall panels  112 ,  116 . In this embodiment, securing panel  174  is glued to the respective adjacent side wall panel. 
   Thereafter, the first side wall panel  112  and bottom wall panel  118  are secured together whereby, in this embodiment, securing flap  126  is secured to bottom panel  118  by glue or other suitable means known in the art. Thus, the carton is in a flat collapsed position ready to be supplied to an end user for loading with articles. 
   In order to erect the carton it is constructed by folding top panel  114 , first side wall panel  112 , bottom panel  118  and second side wall panel  116  out of alignment with each other along fold lines  128 ,  120 ,  122  and  124  respectively, so as to form a tubular structure. 
   The carton is at an intermediate stage of construction whereby the articles are inserted into the carton C′ from one of the ends. End panels  138  and  142  are preferably folded outwardly along fold lines  140  and  144  respectively to guide the articles into the carton C′. More preferably, the opposing end wall is formed prior to receiving the articles, whereby end wall panels  130  and  134  are folded inwardly along fold lines  132  and  136  respectively to be secured together by glue or other suitable means known in the art. 
   In order to complete construction of the carton C′, the end wall panels are secured together. To this end, glue is applied to the inner faces of end wall panels  138  and  142 , and then folded inwardly along fold lines  132  and  136  respectively and into abutment to be secured together. Preferably, the end wall panels  130  and  134  are also secured to part of the outer support panels  180   a  and  180   c  of the corner support structures  170   a  and  170   c  respectively to provide additional securing points. 
   In further embodiments, glue may be applied to different areas of the blank such as where corner support structures are used. Thus the carton is in a set up condition and fully loaded with articles ready to be supplied to the user, as shown in  FIGS. 11 and 12 . 
   It will be seen from  FIG. 12  that the support structures  170   a,    170   b,    170   c,    170   d  are located in the corners of the outer carton to provide additional support for the weaker parts of the carton. 
   In order to gain access to the interior of the carton, the access structure can be opened whereby securing tab  160  is pushed inwardly to reveal the pull tab  158 . Thereafter, the pull tab  158  is pulled in an outward direction which causes the side access panel  151  to be separated from the first side wall panel  112  along frangible lines  155  and  156 . By continuing to pull on pull tab  158  in an upward direction the upper access panel  153  is separated from top wall panel  114  along fold lines  152  and  154  respectively. The access structure is folded backwards along fold line  122  to reveal the contents of the carton. 
   In order to reclose the access structure, there are provided opposing tabs  175   a  and  175   b  that are secured to the inner face of one of the top or side wall panels. In this embodiment, tabs  175   a  and  175   b  are provided by the support panels  176   d,    180   d;  and  176   b,    180   b.  It will be seen from  FIG. 11  that the corner structure  170   a  provides a tab to assist with the re-engagement of the end closure flap. Indeed, it is envisaged that the corner support structure could be replaced by a panel hingedly connected to side wall  112  to provide such a tab. It is envisaged that these tabs could be applied independently of the corner structure and, in fact, could be applied to cartons where no corner structures are provided. 
   The tabs  175   a  and  175   b  are adapted so that the side access panel  151  can be placed within the carton such that the outer face of access panel  151  abuts the inner surface of tab  175   a  and  175   b,  shown in FIG.  11 . In order to engage the side access panel  151 , pull tab  158  or—as the case may be—part of access panel  151 , may be placed securing tab  160  and side wall panel  112  thereby providing a pincer arrangement to secure the pull tab  158  (or access panel  151 ) thereto and to provide a reclosable access structure. 
   The present invention and its preferred embodiments relate to an arrangement for providing a corner post structure in a fully enclosed carton, and for providing a tear-open flap. However, it is anticipated that the invention can be applied to a variety of carriers and is not limited to those of the fully enclosed type hereinbefore described and could be used for numerous applications where it is desired to provide a carrier with improved rigidity. 
   It will be recognised that as used herein, directional references such as “top”, “bottom”, “end”, “side”, “inner” and “outer” do not limit the respective panels to such orientation, but merely serve to distinguish these panels from one another. Any reference to hinged connection should not be construed as necessarily referring to a single fold line only: indeed it is envisaged that hinged connection can be formed from one or more of one of the following: a score line, a frangible line or a fold line; without departing from the scope of invention. 
   It should be understood that various changes may be made within the scope of the present invention; for example, the size and shape of the panels and apertures may be adjusted to accommodate articles of differing size or shape, or alternative top and bottom closure structures may be used, without departing from the scope of the invention. A single glue aperture may be provided in some embodiments. The carton may accommodate more than one article in different arrays.