Containers in the form of erectable trays, cases or the like from one or more piece blanks are known for use in the packaging of goods. Frequently such containers are formed from a single blank cut from a sheet of a laminate which includes at least one corrugated core layer which defines a flute run direction. An example of such a material is a paperboard laminate which includes outer (usually kraft) paper liners having interposed adhesively therebetween a corrugated medium also of paper. Such corrugated medium can be of one or more contiguous layers.

Other forms of such materials may include two separated corrugated layers (each of one or more sheets of paper). For example a double cushion corrugated board is one having three substantially planar paper sheets, each adjacent pair of sheets having interposed therebetween a corrugated medium of one or more sheets of paper. Preferably such double cushion material has the flute run direction of each corrugated layer running parallel.

Such corrugated board materials with a flute run direction have a stacking strength capability greater where the flutes run vertically as opposed to horizontally. Various forms of container have been evolved to take advantage of such directionality of the material. Some make good use of the material in this respect such as our DEFORM product range (see New Zealand Patent Specification No. 270912) or the P84TM product form of IberoAmericana.

Others may make less effective use of such directionality.

The present invention relates to an improved container of a kind where a blank of such a material is to be erected to a container form which is to have stack indexing capability. The present invention recognises an advantage to be derived from indexing one on top of another reliant on an underlying cut edge transverse to the flute run direction. It is to deriving that advantage that the present invention has as an object.

In our New Zealand Patent Specification No. 270912 we disclose a tray like product range erectable from a single piece blank which has given rise to the DEFORM product range.

The full content of that specification is here included by way of reference.

The present invention in one aspect is directed to tray or container forms that are a variant of the aforementioned DEFORTM product range or which are capable of being offered as a potential replacement therefor.

It is therefore another object of the present invention in respect of some aspects of the invention to provide blanks and containers erectable from such blank having novel aspects over aforementioned tray or. container forms.

In a first aspect the present invention consists in a container formed from a blank, the blank itself having been cut (by any means) from a sheet of a laminate which includes at least one corrugated core layer which defines a flute run direction, said container comprising or including a rectangular or square base, a flap sequence of two indexing wall flaps extending from each of two opposed sides of said base, the first indexing wall flap of each flap sequence being connected to the base at a first fold line, the second indexing wall of each flap sequence being connected to its associated first indexing wall flap by a second fold line parallel to its said first fold line, and each indexing wall flap of each flap sequence having an extension flap at each end thereof beyond a fold line (or curvature commencement) extending substantially normal to said first and second fold lines, and a non indexing wall flap extending from each of the other two sides of said base, wherein said container has said second indexing wall flap of each flap sequence inwardly of its associated first indexing wall flap and one or both of the flap extensions at each end of that flap sequence is directly affixed to a non indexing wall flap, and wherein, above a transition between each associated first and second indexing wall flap of an indexing wall flap sequence there is defined at least one indexing projection stack indexable, or each stack indexable, by an identical container reliant on a cut, or cuts, of the blank which in the erected container provide an accessible (or accessible) from below opening (s) and/or scallop (s) for that purpose, and wherein, an extension flap of each second indexing wall flap at least in part triangulates (in a straight, curved and/or other manner) a corner directly or indirectly to the non indexing wall flap to define in conjunction with part of said first indexing wall flap at the corner and with part of the adjacent non-indexing wall (and optionally with part of the flap extension of the first indexing wall) a column like vertical load supporting structure, and wherein (i) the or each indexing projection is flanked on either side in its indexing wall by a hinging transition between a said first indexing wall flap and a second indexing wall flap and (ii) at least at about the level of such hinging transition, or there above, further from each hinging region and the indexing projection, there is upwardly exposed by both indexing wall flaps of each indexing wall load supporting cut edges of the laminate, such cut edges being transverse to the flute run direction.

Preferably where there is more than one indexing wall projection per indexing wall preferably a said cut edge is defined between each projection and in part at or towards a triangulated corner.

Preferably a said cut edge to the same level as said aforementioned cut edge (s) is defined in part by one or preferably both of the indexing wall flap extensions (e. g. including in said triangulation).

Preferably each second indexing wall flap sits on a pre-crushed region of the base.

Preferably a scallop is interposed between each said hinging transition and (the more outwardly) said cut edge.

In a further aspect the present invention consists in a container of a kind having one or more indexing projections each skirted in its wall by a hinge region and skirted there beyond in its wall by exposed cross cut flutes substantially as hereinafter described with reference to any one or more of the accompanying drawings.

In yet a further aspect the present invention consists in a blank suitable for a container as aforesaid.

In yet a further aspect the present invention consists in a blank substantially as hereinafter described with reference to Figure 1,3 and 4 of the accompanying drawings or any single indexing wall projection variant thereof.

In yet a further aspect the present invention consists in the use of blanks and/or containers in accordance with the present invention.

In yet a further aspect the present invention consists in a stack of stack indexed containers as previously defined.

Accordingly in another aspect the present invention consists in a container formed from a blank of a laminate having a corrugated flute run direction, said container comprising or including: a rectangular base having an opposed pair of longer sides and an opposed pair of shorter sides, said base including a plurality of openings, a flap sequence of two indexing wall flaps extending from each of the sides of a pair of sides of said rectangular base, a first indexing wall flap of each flap sequence being connected to the base by a fold line, and the second indexing wall flap of each flap sequence being connected to the first flap, and each indexing wall flap of each flap sequence having an extension flap beyond a fold-line extending normal or substantially normal to said fold-line of said first indexing wall flap with the base, and a non-indexing wall flap extending from each of the other sides of said base, wherein said container, when erected, has each indexing wall flap sequence folded to define an upwardly directed (preferably slightly inwardly inclined) indexing wall, and, in the erected form, above a transition between each sequence of the first indexing wall flaps and second indexing wall flaps there is or are defined by the indexing wall at least one projection, the or each projection being indexable by one of said plurality of openings of the base of another erected container in a stacking configuration, and wherein, the blank has been formed such that each wall flap of each indexing wall flap sequence has, as the transition therebetween, at least one hinging axis above which some of the blank material projects from one wall flap to hinge at the distal limit of the projection and then be returned back to adhere to at least part of the wall structure, and wherein there is at least one hinging zone at the transition resulting from the non cutting fully of the blank material along the transition such that there is defined at the top of each indexing wall both exposed flute end cut regions for direct bearing thereof under a like container in a stacking condition and at least one hinging link.

In some forms of the present invention the non cutting fully of the blank material is a mixture of full cutting along certain parts of the transition to leave some linking or bridging regions uncut (irrespective of whether or not, to assist the hinging function, there is any cutting normally to the transition to better render flexible for hinging purposes the linking or bridging region).

In some forms of the present invention the extensions from each indexing wall flap of an indexing wall flap sequence is disposed one on either side of the adjacent non indexing wall flap (ie; sandwiches the same). In some forms one of such extensions can triangulate, curve or otherwise truncate across the corner of the base thereby to define a column structure form.

In other preferred forms of the present invention both extension flaps of each indexing wall flap sequence are fixed one to the other internally of the associated non indexing wall flap with one only of the extensions preferably directly being adhesively affixed to the non indexing wall flap.

In such a construction there can if desired be a truncation of the corner to provide a column type feature by the more inwardly of the two flap extensions.

In other forms there may be no such truncation.

Preferably there are a plurality of projections on each indexing wall structure.

Preferably the indexing projection or projections is on the longer pair of sides of the rectangular base.

In other forms there can be instead be on the shorter pair of sides.

In still a further aspect the present invention consists in a blank suitable for forming a container as aforesaid or as hereinafter described.

Persons skilled in the art will appreciate the various embodiments within the ambit of the present invention.

A preferred form of the present invention will now be described with reference to the accompanying drawings in which Figure 1 is one option for a blank in accordance with the present invention, Figure 2 shows an erected container of a kind having two indexing projections on each indexing wall and a column like triangulated corner structure, Figure 3 shows by reference to a double cushion corrugated board material a corner of a container as shown in Figure 2, the indexing projection in such a variant being a pop-up single type projection as depicted in Figure 2 (of course other forms of indexing projection above the transition being capable of being provided such as those that by doubling the projection back and re-attaching it in some way provide no exposure of the flutes at the top of the indexing projection).

Figure 4 is a plan view of a blank of another embodiment of the present invention, such an embodiment being an adaption of the DEFORTM type container, and Figure 5 shows an alternative embodiment of the present invention.

Forms of the present invention will now be described as options of the present invention with reference to a double cushion paperboard. In the preferred form shown in the drawings the base 1 is rectangular and each longer side has two indexing projections on each indexing wall.

As can be seen from Figure 1 fold lines"I-I"and"II-II"separate the base 1 from each indexing wall flap sequence, with the first indexing wall flap 3 being hinged by the fold line"I-I"from the longer side of the rectangular base 1 and with the more outwardly in the blank second indexing wall flap 4 hinged by a fold line"II-II"from the flap 3.

As can be seen separating each of the flaps 3 and 4 are cuts 10 which leaves hinging regions 12 skirting on either side of the cuts 8 which provide the indexing pop-up projection 11. As can be seen more outwardly of each hinging region 12 is an exposed cut face provided by (in the preferred form) both of the flaps 3 and 4, ie; see 13,14, 15 and 16.

It can bee seen that cutouts 9 are provided for indexing purposes at or adjacent or both the fold lines I-I so as to index receive a projection 11 in each instance of a like container.

The non indexing wall flaps 2 are hinged on the broken line by a fold line 17 from the base 1 and this up folded flap 2 is to have adhesively affixed thereto first the flap extension 5 of the first indexing wall flap 3 and thereon the part 6 of the flap extension of the second indexing wall flap 4. The fold lines shown in the blank leave a triangulating (preferably straight) region 7 which triangulates the corner to provide the column like form depicted in the figures.

Persons skilled in the art will appreciate that if desired the flap 5 could be adhesively affixed outwardly of the flap 2 and the flap extension 6 instead be glued directly on to the up folded non indexing wall flap 2 such as, for example, in the DEFORTM case of Carter Holt Harvey Limited.

In the preferred form of the present invention the base 1 is preferably pre-crushed in those regions that are to overlie an exposed flute cut edge 13,14, 15 and 16 and preferably also 17 and 18. Indeed such pre-crushing prior to carton erection will assist in clearance for the flaps during the assembly stage.

As can be seen the present invention enables a single level for the transversely cut material to be presented by regions 13,14, 15,16, 17 and 18 and such a level is at least at if not above the level (at least after any crushing) of the hinging regions 12.

As mentioned earlier the pop up type indexing projection which extends above the transition between the first and second indexing wall flaps in the erected container could alternatively be a different form such as that utilised by a number of companies where an even greater cut out has part thereof folded back and adhesively or otherwise reattached to some part of the indexing wall.

Persons also skilled in the art will appreciate that scallops or the like 19 can be provided between the hinging regions 12 and the outwardly flanking cuts 10 that provide the support regions 13,14, 15 and 16. Such scallops for convenience are not shown in Figure 1 other than in broken outline as they are optional.

In the embodiment as shown in Figure 4 there is a substantially rectangular base 19 having two wall flap sequences 20. There is an indexing wall flap 21 and an indexing wall flap 22 and cuts from one into the other to define a lug forming projection 23 which will hinge at 24 with the distal region 25 being down turned to adhere inwardly of the indexing wall (when formed) against the reverse side of the member 22 and/or the revealed face of the member 21.

Each member 21 and 22 has extensions 26 and 27 respectively. Extension 26 is adapted to lie outwardly of the non indexing wall flap 28 when it is erect whilst the extension 27 with its fold lines 29 is adapted to truncate the interior (as in the DEFORTM container) with the region 30 itself only being affixed inwardly to the member 28.

Equally within the scope of the present invention however are variants of the arrangement of Figure 1 where both members 26 and 27 are affixed inwardly of the non indexing wall flap 28 with the member 26 directly adhered thereto and the portion 27 of the extension 30 affixed thereto so as still to provide a column like structure which truncates the corner.

In the erected condition openings 31 accommodate the appropriate projections thus formed.

In the arrangement as shown the cross hatching shows regions of pre-crushing of the preferred corrugated board medium, eg; a paperboard liner, at least one corrugated core to provide the flute run direction and a further liner. There can be multiple players of corrugated medium interposed if necessary by further sheets of appropriate material. In the preferred form of the present invention the flute run direction is in the arrowed direction (likewise in Figure 5).

An aspect of the present invention is the full cutting at regions 32 but the allowing of bridges 33 on the transition zone to provide the hinging links. Obviously these transitions 33 need not be directly against each projection being formed and indeed can be spaced therefrom, ie; there can be cuts right to the projections from a remote bridging of the flaps.

An advantage of the arrangement however is that cut flute exposed edges of each of members 21 and 22 provide a region which without pre-crushing is ready to directly to bear weight in an indexed stacked condition.

Figure 5 shows an alternative where, just as an example, the indexing lugs are provided at the lesser ends and no provision is made for truncating of the corners. Persons skilled in the art will appreciate however the provision of the indexing lugs and corresponding openings on either the greater or lesser sides of the rectangular base does not dictate the form that must be used. Indeed, especially with the end indexing forms, even one projection only may suffice per indexing wall.

With the arrangement as shown in Figure 5 there is preferably still angling inwardly slightly as with the indexing wall flap sequence 20 of the embodiment of Figure 4, but not necessarily so. With the arrangement as shown in Figure 5 the extensions 34 and 35 respectively are adapted to be affixed inwardly of the non indexing wall flaps 36 and not to truncate the corner. Flap 35 affixes to flap 34 which is directly affixed to the non indexing wall flap 36 which, as shown, includes a lidding flap 37.

Any lidding flap is of course an optional feature of any variant of the present invention.

In the arrangement as shown in Figure 5, the cut regions 38 which correspond to cut regions 32 of the embodiment of Figure 4 leaves bridging regions 39 which are the equivalent of the bridging regions 33.

Persons skilled in the art will appreciate how such positioning could instead be utilised with the embodiment of Figure 4. Again pre-crushing is shown as shaded and preferably the indexing wall (this time the end wall) when erected is slightly inwardly inclined. Again the exposed flute cuts 38 provide for a direct load bearing on a pre-crushed base region.

Persons skilled in the art will appreciate how the present invention offers alternatives to existing forms.