Abstract:
There is disclosed a blank for forming a wrap-around carrier sleeve comprising a plurality of panels connected end to end, including first and second end panels at opposite ends of the blank configured to overlap and cooperate to form a bottom of the sleeve. The first end panel includes at least one retainer flap struck from the panel. The second end panel includes at least one male supporting tab connected to the second panel. Each male supporting tab has a notch formed along one side, the notch being sufficiently offset from the fold line in the neck so that, when the second panel overlaps the first panel and the male supporting tab extends through an opening formed by the retainer flap in the first panel, the notch in the male supporting tab lockingly engages a raised edge of the retainer flap.

Description:
BACKGROUND OF THE INVENTION 
   This invention relates to wrap-around article carriers, sleeves and sleeve blanks. 
   Wrap-around article carriers are used to enclose a plurality of similarly shaped articles, such as beverage containers. Typically, such an article carrier comprises a sleeve with at least partially open ends. The sleeve is formed by folding a blank comprising a plurality of panels which become the top, bottom and sides of the sleeve. Usually, such a blank will have a generally rectangular shape with end portions of the blank interlocking to form a continuous sleeve for enclosing articles. The blank is constructed from a material that is suitable for folding while possessing sufficient rigidity and strength for use in an article carrier. Paperboard is a common material used in manufacture of article carrier sleeves. 
   Article carrier sleeves of the kind described above may be rapidly assembled to enclose articles by using machinery designed to form a sleeve from a blank. Such machinery folds the blank into a sleeve surrounding the articles and engages cooperating locks of the blank to maintain the sleeve in an erect state around the articles. 
   Having at least partially open ends of the sleeve reduces the amount of material required in constructing the article carrier and the number of steps required to form the carrier. However, the absence of material at the ends of the sleeve makes it possible for articles retained within the sleeve to move outwards through the end of the sleeve, possibly falling out, unless some feature is provided for limiting such outward movement. Outward movement of articles retained within the sleeve is a particular problem where the configuration of the articles at the top of the sleeve is different from that at the bottom of the sleeve, such as where the articles are bottles having a narrow neck portion, and a broader curved base portion. 
   Previous approaches to addressing the above problem include U.S. Pat. No. 5,094,347 issued to Schuster (&#39;347 Schuster), U.S. Pat. No. 5,107,986 issued to Cooper (&#39;986 Cooper). and U.S. Pat. No. 5,390,848 issued to Gungner et al. (&#39;848 Gungner et al.). &#39;347 Schuster, &#39;986 Cooper, and &#39;848 Gungner et al. provide integral article retaining features within the sleeve which are essentially three-dimensional protuberances formed in the bottom of the sleeve adjacent open ends of the sleeve. However, in each case, the machinery used for forming the sleeve must include a movable punch or rod element that forces a retainer flap through a corresponding opening in the inner bottom panel. 
   In other known sleeve designs, it is not necessary to have movable punch or rod elements in order to form a sleeve. Examples of such sleeves are those provided under the trademark JAK-ET-PAK, as described in U.S. Pat. No. 4,708,284 issued to Sutherland et al. (&#39;284 Sutherland et al.). In &#39;284 Sutherland et al., during formation of the sleeve, a male tab is first folded and then is pushed, by a ramp over which a part of the blank travels, through a corresponding opening (such as a slit) in an inner overlapping portion of the bottom panel of the sleeve so that the male tab extends within the sleeve and is engaged therein. The male tab serves as a secondary locking element for the sleeve and the tab may be positioned within the sleeve so as to separate adjacent articles held within the sleeve. While the kind of automated packaging machinery used to form the sleeve in &#39;284 Sutherland et al. does not require a punch or rod element to push the male tab through the corresponding opening, the &#39;284 Sutherland et al. design lacks the three-dimensional nature of the protuberances found in &#39;347 Schuster, &#39;986 Cooper, and &#39;848 Gungner et al. 
   Another known design in which it is not necessary to have movable punch or rod elements in the machinery forming the sleeve, but which does provide a three-dimensional protuberance, is disclosed in U.S. Pat. No. 5,437,363 issued to Gungner (&#39;363 Gungner). By forming a three-dimensional protuberance from a retainer flap using a male supporting tab, &#39;363 Gungner is intended to provide the article retaining features of &#39;347 Schuster, &#39;986 Cooper, and &#39;848 Gungner et al., while maintaining simplicity in formation associated with the sleeve in &#39;284 Sutherland et al. However, the sleeve in &#39;363 Gungner suffers from the drawback that the structural integrity of the three-dimensional protuberance may be compromised. What is needed is an improved design for an article retaining sleeve that addresses this drawback. 
   SUMMARY OF THE INVENTION 
   This invention provides a blank for forming a wrap-around carrier sleeve comprising a plurality of panels connected end to end, including first and second end panels at opposite ends of the blank configured to overlap and cooperate to form a bottom of the sleeve. The first end panel will be the inner bottom panel of the sleeve and includes at least one retainer flap struck from the panel. The retainer flap is joined to the first panel along a fold line. A free end of the retainer flap forms an opening in the first end panel to receive a corresponding male supporting tab. The second end panel will be the outer bottom panel of the sleeve and includes at least one male supporting tab connected to the second panel. The point at which the male supporting tab is connected to the second panel may have a fold line provided thereat facilitating folding of the male supporting tab during sleeve formation. Each male supporting tab has a notch formed along one side, the notch being sufficiently offset from the fold line in the neck so that, when the second panel overlaps the first panel and the male supporting tab extends through the opening in the first panel from which the retainer flap is struck, the notch in the male supporting tab lockingly engages a raised edge of the retainer flap. The retainer flap and the male supporting tab form a locked three-dimensional protuberance within the sleeve that serves to more securely limit movement of an article adjacent the retainer flap in the sleeve towards an open end of the sleeve. 
   Each male supporting tab may have a basal notch formed on an opposite side of the offset notch, the basal notch being adjacent the base of the neck so that, when the male supporting tab is fully extended through the opening in the first panel, the basal notch engages the inner bottom panel formed by the first panel. Various designs for the basal notch are known in the art and may be employed in this invention. 
   In an embodiment, each retainer flap may have at least one secondary fold line extending from an edge of the retainer flap not connected to the first panel, such that as the retainer flap is raised by the male supporting tab, the retainer flap is folded and forms an apex at an edge of the retainer flap. In this case, the apex is lockingly engaged in the offset notch in the male supporting tab. 
   In an embodiment, the retainer flap has at least two secondary fold lines, each having a configuration generally corresponding to the configuration of the outer surface of an adjacent article to be retained, whereby the shape of the facets formed when the retainer flap is folded at the secondary fold lines will complement the outer surfaces of adjacent articles. 
   In an aspect of the invention, there is provided a blank for forming a wrap-around article carrier sleeve comprising a plurality of panels connected end-to-end including first and second end panels at opposite ends of the blank that cooperate to form a bottom of the carrier sleeve, wherein the first end panel includes at least one retainer flap struck from the panel thereby defining an opening in the panel, the retainer flap being joined to the first end panel at a fold line, and wherein the second end panel is configured to underlie the first end panel outside the bottom of the carrier sleeve and includes at least one male supporting tab joined to the second end panel; and wherein the male supporting tab is configured to extend through the opening in the first panel from which the retainer flap is struck, the male supporting tab having a notch formed on one side, the notch being offset from the point at which the male supporting tab is joined to the second end panel and configured to lockingly engage a raised part of the retainer flap within the carrier sleeve when inserted into the opening during formation of the carrier sleeve. 
   In an embodiment, a fold line is provided at the point at which the male supporting tab is joined to the second end panel, such that the notch is offset from the fold line. 
   In another embodiment, the notch is configured to lockingly engage a raised edge of the retainer flap when the male supporting tab is inserted into the opening during formation of the carrier sleeve. 
   In another embodiment, the retainer flap has at least one secondary fold line extending from an edge of the retainer flap not connected to the first panel for facilitating folding of the retainer flap. 
   In another embodiment, the retainer flap when raised and folded at the at least one secondary fold line is configured to form an apical edge, and wherein the notch of the male supporting tab is configured to lockingly engage the formed apical edge. 
   In another embodiment, each secondary fold line is curved. 
   In another embodiment, the notch of the male supporting tab is a first notch and the male supporting tab has a basal notch configured to lockingly engage the first end panel when the male supporting tab is inserted into the opening during formation of the carrier sleeve. 
   In another embodiment, the basal notch is formed on a side opposite the side having the first notch. 
   In another embodiment, the fold line joining the retainer flap to the first panel is positioned more adjacent an outer side edge of the first panel than the raised part of the retainer flap. 
   In another embodiment, the fold line joining the retainer flap to the first panel is positioned adjacent an outer side edge of the first panel, and the raised edge of the retainer flap is oriented inwardly from the outer side edge. 
   In another embodiment, two secondary fold lines extend from opposite edges of the retainer flap and generally converge towards the raised edge of the retainer flap such that, when folded at the secondary fold lines, the retainer flap is configured to form an apical edge suitable for locking engagement in the notch. 
   In another embodiment, the fold line joining the retainer flap to the first end panel is substantially perpendicular to the fold line joining the male supporting tab to the second end panel. 
   In another embodiment, the blank further comprises male and female primary locking elements for locking engagement of the first and second panels in the carrier sleeve. 
   In another embodiment, the blank has two male supporting tabs adjacent opposite sides of the second panel and two retainer flaps adjacent opposite sides of the first panel. 
   In another aspect of the invention, there is provided a wrap-around article carrier sleeve formed from a blank comprising a plurality of panels connected end-to-end including first and second end panels at opposite ends of the blank that cooperate to form a bottom of the carrier sleeve, wherein the first end panel includes at least one retainer flap struck from the panel thereby defining an opening in the panel, the retainer flap being joined to the first end panel at a fold line, and wherein the second end panel is configured to underlie the first end panel outside the bottom of the carrier sleeve and includes at least one male supporting tab joined to the second end panel; and wherein the male supporting tab is configured to extend through the opening in the first panel from which the retainer flap is struck, the male supporting tab having a notch formed on one side, the notch being offset from the point at which the male supporting tab is joined to the second end panel and configured to lockingly engage a raised part of the retainer flap within the carrier sleeve when inserted into the opening during formation of the carrier sleeve. 
   The foregoing and other aspects of the invention will be apparent from the following more particular descriptions of exemplary embodiments. 

   
     BRIEF DESCRIPTION OF DRAWINGS 
     In the figures which illustrate exemplary embodiments of the invention: 
       FIG. 1   a  is a plan view of a flat blank for forming a carrier sleeve in accordance with an embodiment of the invention. 
       FIG. 1   b  is an enlarged detail of a retainer flap struck into a first end of the blank shown in  FIG. 1   a.    
       FIG. 1   c  is an enlarged detail of a male supporting tab connected to a second end of the blank shown in  FIG. 1   a.    
       FIG. 2  is an enlarged plan view of the first and second ends of the blank shown in  FIG. 1   a , which form the inner and outer bottom panels of the sleeve respectively, just prior to being positioned in an overlapped condition. 
       FIGS. 2   a – 2   c  are a sequence of plan views showing how the male supporting tab of  FIG. 1   c  engages the retainer flap of  FIG. 1   b  to form a wrap-around sleeve. 
       FIGS. 3   a – 3   c  are a sequence of cross-sectional views taken from  FIGS. 2   a – 2   c.    
       FIG. 4  is an end view of a formed sleeve, with the retainer flap of  FIG. 1   b  raised into a locked three-dimensional protuberance to retain articles in the sleeve. 
       FIG. 5  is a perspective view of the formed sleeve of  FIG. 4  with some of the articles removed to show the locked three-dimensional protuberances formed by the retainer flaps. 
       FIG. 5   a  is a partial perspective view detailing the locked three-dimensional protuberance formed by the retainer flap of  FIG. 1   b  and male supporting tab of  FIG. 1   c.    
       FIG. 6  is another perspective view of the formed sleeve as shown in  FIG. 5  but with some of the articles replaced. 
   

   DETAILED DESCRIPTION 
   Referring to  FIGS. 1   a – 1   c , a blank  100  of this invention comprises a substantially rectangular sheet of paperboard or other suitable material. The blank  100  comprises a plurality of panels connected end to end, including a middle panel  102  that will form the top of the wrap-around article carrier sleeve and side panels  103   a ,  103   b  that will form sides of the sleeve. Top panel  102  may be provided with through-holes or cut-away portions  104  for receiving the top portion of articles to be enclosed by the sleeve and a handle  105 , which in this embodiment is a through-hole. The blank  100  also comprises first end panel  106  and second end panel  107  located at opposite ends of the blank  100 . Each end panel  107 ,  106  is connected to a side panel  103   a ,  103   b , respectively, at fold lines which in this embodiment are fold lines  109 . Likewise, side panels  103   a  and  103   b  are connected to top panel  102  at fold lines  108   a . Secondary fold lines  108   b  and  108   c , as shown in this illustrative example, may be suitably positioned to allow a sleeve  100   a  formed from the blank  100  to better fit around the shape of the articles to be held in the sleeve (e.g. as shown in  FIG. 3   a ). 
   Fold lines  109  define the bottom edges of the sides of the sleeve  100   a . Situated along fold lines  109  are cut-outs  110  that provide clearance for the bottom of articles enclosed within the sleeve  100   a.    
   End panel  106  has two retainer flaps  120 , each of which is hinged to the bottom panel  106  at fold line  122  and comprises three sections  120   a ,  120   b ,  120   c , separated by secondary fold lines  126  (as best shown in  FIG. 1   b ). These retainer flaps are struck during formation of the blank  100 . As will be further detailed below, the sections  120   a ,  120   b ,  120   c  of the retainer flaps  120 , once folded at the fold lines  126  and at hinge line  122 , form an apex at an edge  121  of the retainer flaps  120 . Fold lines  122  are adjacent to and generally parallel with the sides of bottom panel  106 . In an embodiment, the entire length of section  120   b  may be attached to the end panel  106  at hinge line  122 , so as to provide maximum support for the three-dimensional protuberance formed by the retainer flaps  120  (as will be detailed further below). 
   As shown in  FIG. 1   b , adjacent each retainer flap  120  is a slit  125 . To facilitate entry of a male support tab  128  (of bottom panel  107 ) through the slit  125  during formation of the sleeve  100   a,  a parallel score line  123  and a curved cut line  124  may be provided in known manner. A cut-out  127  provided adjacent the retainer flap  120  becomes a primary female locking element for the formed sleeve  100   a  (as will be explained further below). 
   Two male supporting tabs  128  extend from bottom panel  107  and are connected to the bottom panel  107  by necks having fold lines  129 . Formed into one side of each male supporting tab  128  is a notch  143  (as best shown in  FIG. 1   c ) offset from the fold line  129  in the neck by an offset distance “A”. The offset distance “A” is suitably selected so as to allow notch  143  to receive and lockingly engage apical edge  121  of retainer flap  120  when the retainer flap  120  is raised by the male supporting tab  128 . In this illustrative example, the notch  143  is formed below a nose  142  protruding from one side of the male supporting tab  128 . However, it will be appreciated that any notch capable of receiving and lockingly engaging a raised portion of the retainer flap  120  may be provided on the male supporting tab  128 . 
   In an embodiment, formed into each male supporting tab  128  on a side opposite the side of the notch  143  is a basal notch  145 . As shown, in known manner, the basal notch  145  is formed below a nose  140  with virtually no offset from the fold line  129 . As will be explained further below, the basal notch  145  of a male supporting tab  128  may further secure the tab when forming a three-dimensional protuberance with a corresponding retainer flap  120 . 
   As will be appreciated by those skilled in the art, the male supporting tabs  128  and corresponding retainer flaps  120  are designed to form a secondary lock for the sleeve  100   a  and to better support articles within the sleeve. In order to provide additional support for the articles contained in the formed sleeve  100   a , primary male locking elements  132  (formed by slits that interrupt fold line  131 ), engage the primary female locking elements  127  of bottom panel  106 . The formation of the sleeve  100   a  from blank  100 , including engagement of the primary male locking elements  132  and primary female locking elements  127 , will now be explained. 
   In the present illustrative embodiment, as a first step, the neck of articles (e.g. bottles)  200  are inserted through cut-out  104  in middle panel  102  of the blank  100 . 
   Referring now to  FIG. 2 , bottom panel  106  and outer bottom panel  107  are shown at a stage in forming the sleeve  100   a,  wherein the panels  106 ,  107  are about to be overlapped so that panel  107  will underlie panel  106  at the bottom of the sleeve. Panel  107  is brought to underlie panel  106 , so that male supporting tabs  128  align with retainer flaps  120 , and primary male locking elements  132  align with primary female locking elements  127 . 
   As show in  FIG. 2   a,  and in the corresponding cross-section in  FIG. 3   a , the primary male locking elements  132  are inserted into the primary female locking elements  127  and engage an edge  150  of the female locking elements  127  so that the bottom panels  106 ,  107  are prevented from separating from each other (at least to the extent of the designed rip strength of the material used for blank  100 ).  FIG. 3   a  shows illustrative bottles  200  in dashed outline to indicate how the sleeve  100   a  is formed in place around such bottles  200 , with the top portion of the bottles being received in the cut-outs  104  of the sleeve  100   a . As shown, the bottom panel  107  may be folded at fold line  131  in order to properly angle the primary locking elements  132  for insertion into the primary female locking elements  127 . 
   Now referring to  FIG. 2   b , and the corresponding cross-section in  FIG. 3   b , each male supporting tab  128  is shown folded at the neck at fold line  129 , and the leading edge of each male supporting tab  128  is positioned next to a corresponding slit  125  in preparation for insertion into the slit  125 . As explained above with respect to  FIG. 1   b,  score lines  123  and secondary curved cut lines  124  may be provided to make insertion of the male supporting tabs  128  into the slits  125  easier. Also, as shown, the primary female and male locking elements  127 ,  132  will maintain the panels  106 ,  107  in position relative to each other during this insertion procedure. 
   Referring to  FIG. 2   c , and the corresponding cross-section in  FIG. 3   c , the male supporting tabs  128  are shown inserted into the corresponding slits  125 . As the male supporting tabs  128  are inserted, each retainer flap  120  connected to bottom flap  106  at fold line  122  is raised at its free end by a leading edge of a respective male supporting tab  128 . In the illustrative example, each fold line  122  is substantially perpendicular to fold line  129  of the corresponding male supporting tab  128 . 
   In this illustrative example, the raised edge of the retainer flap is oriented inwardly from an outer edge of the panel  106 . As the male supporting tabs  128  are further extended into the slits  125 , apical edge  121  of the raised retainer flap  120  snaps into a notch (offset notch  143  in  FIG. 1   c ) formed into the side of the each male supporting tab  128 . The notch  143  lockingly engages a raised part of the retainer flap  120  and a locked three-dimensional protuberance is formed inside sleeve  100   a  (as best shown in  FIGS. 5 and 5   a ). Such a fully formed three-dimensional protuberance is shown in an end plan view of the sleeve  100   a  in  FIG. 4 . 
   In the present illustrative example, as shown in  FIG. 5 and 5   a , the three-dimensional protuberance is formed by folding the retainer flap  120  along suitably shaped secondary fold lines  126 . In this regard, it will be appreciated that placement of the bottles  200  will assist in causing the retainer flaps  120  to fold along the fold lines  126 . The three sections  120   a ,  120   b ,  120   c  of the retainer flaps  120  folded along fold lines  126  form a pyramid-like structure with an apical edge  121  ( FIG. 1   b ) at the top of the sections  120   a ,  120   b ,  120   c . The apical edge  121  is received by the notch  143  formed on one side of the male supporting tab  128  to securely lock the pyramid-like structure in position. 
   Still referring to  FIGS. 5 and 5   a , as shown, the secondary fold lines  126  may be suitably shaped to conform to the shape of the bottles  200  to be retained. In this example, the curve of the fold lines  126  allow the base portions of the bottles  200  to be seated more securely against the three-dimensional protuberance formed by the retainer flaps  120  and male supporting tabs  128 . 
   As shown in  FIG. 5   a , in the present illustrative embodiment, basal notches  145 , as known in the art, may also be provided opposite the side of the offset notch  143 . The basal notches  145  may provide a more secure lock for the three-dimensional protuberance by preventing the male supporting tabs  128  from being readily withdrawn from the slots  125 . 
   Formation of the carrier sleeve as illustrated in the preceding figures may be carried out on machinery for forming folding carton wraps with a “lock-bottom” such as are provided under the trademark JAK-ET-PAK and the carrier sleeve described in U.S. Pat. No. 4,708,284, the contents of which are incorporated by reference herein. Such machinery is designed to fold a male supporting tab similar to that shown in the figures as male supporting tab  128  and direct such a tab through corresponding openings or slits in a sleeve panel without the need for separate movable punches or rod elements in the machinery. 
   Advantageously, a three-dimensional protuberance that is securely locked in position may allow articles (e.g. bottles)  200  to be better retained within the formed sleeve  100   a . At the same time, the simplicity in forming the sleeve  100   a  with less complex sleeve forming machinery has been retained. 
   While exemplary embodiments of the invention have been shown and described, it will be appreciated by those skilled in the art that variations and modifications may be made without departing from the scope of the invention. 
   Thus, the scope of the invention is limited only by the following claims.