CONVERTIBLE CARTON This invention relates to what might generally be designated or characterised as folding or collapsible'packaging structures'-such as bags, carriers, containers, cartons and trays.

These may have a support, display, transport, containment and storage role.

Aspects of the invention are particularly, but not exclusively, concerned with a packaging structure capable of'transformation', conversion or transition, from'flat- pack'storage, to erect carton/carrier bag configuration for'contents fill', through to a tray format, for contents display and access.

Terminology The term'packaging'is used herein to embrace either partial or complete enclosures, envelopes or wraps.

'Flat-Pack' Carton or bag collapsibility is advantageous for'flat-pack'storage, ready for issue or dispensing, and preparatory to erection for'contents fill'-and also upon contents emptying and disposal, after use.

Thus pre-collapsed, or'flat-pack'carrier bags, typically of paper or plastics sheet, are widely used in retail grocery outlets-often mounted upon a dispenser stand at a 'check-out'or till counter.

Flat-pack bag dispensing can embrace a single flat sheet, or a pre-folded, flattened or laid flat sheet-in either case allowing compact, stacked, storage.

For a satisfactorily robust paper carrier bag, a fairly elaborate multi-element, bonded and re-inforced assembly is required, such as for panel overlap, side edge joins and

handles-with attendant manufacturing complexity and cost.

Plastics bags also require sophisticated machinery and the material ingredient is inherently costly.

Bio-degradability and re-cycling may also be'environmentally-friendly'concerns for material consumption.

Cartons are not generally used to substitute for bags-except incidentally when discarded bulk loose product packaging is offered for customer adoption and onward disposal.

Cartons can be erected from carton blanks, themselves (die) cut or stamped from sheet material.

Disposability A flat-pack carton or bag can be discarded in a more compact configuration, or re- erected and re-deployed for re-use.

'Self/Quick-Erection' A facility or pre-disposition (eg by pre-assembly sequence or configuration) for ready, self', or at least quick, erection'-from a (2-D) flat-pack collapsed form, to a hollow (3-D) erect, contents storage, form (and vice-versa)-is convenient.

Moreover, erection or collapse, through certain (simple) actions (such as pulling apart opposed panels or the application of pressure)-is desirable, for ease and speed of use.

'Snap-Action' A (perceived)'snap-action'unfolding and collapse imparts a satisfying, reassuring signal of controlled behaviour and conformity to an intended outcome.

Transition between forms is intended to be'automatic', or self-energised through material resilience to folding, upon certain-desirably minimal and intuitive-manual handling actions, generally from an intermediate pre-folded dispensing form.

This may be achieved while material being folded has some positive residual inherent 'body', resilience or'spring'-say through un-crushed paper fibres-but may be difficult to sustain upon repeated use.

Thus, some default'imposed' (manually-assisted) erection and collapse folding sequence is desirable.

Unitary Fabrication Generally, carton assembly and erection, without laborious (bonded) joints, discrete fasteners or intricate interfit is desirable.

Indeed, for simplicity and economy of production, and resistance to inadvertent (liquid) contents seepage or leakage, (unitary) fabrication from a single piece, ie without edge joins, is desirable.

This in turn dictates a careful relative disposition of folds-and avoidance of cuts- between panels.

Foodstuffs-Transport, Storage & Dispensing Foodstuffs represent a particular packaging problem, particularly for point-of-sale merchandising-and indeed informal'grazing'consumption.

Hot (pre) cooked food-such as in a so-called'fast-food'restaurant, is commonly dispensed in foil trays or dishes, packed within carry cartons or bags, from which individual contents have to be extracted, for local (in-house) or remote consumption.

The carry-carton or bag is not particularly well-adapted, or convenient for subsequent contents access, removal or contents consumption.

It is generally not envisaged that contents be consumed direct from carry-carton or bag.

Nor is the carry-carton or bag intended as a gift-wrap for the contents, or a long-term packaging solution.

Access to food contents for consumption has immediate hygiene implications.

Hygiene considerations dictate minimal direct food handling, and prohibit contact between food and non-sterilised counter or table worktop surfaces.

In practice, for (local) consumption within a (fast-food) restaurant environment, a customer would take the filled bag or carton to a table or counter and open the bag or carton in order to gain access to the contents.

In doing so there is a risk of inadvertent contents spillage, contact with non-sterile surfaces, and waste.

Absent sterile table wear, vis crockery or even paper plates, this entails repeated food handling and consequent messy, soiled fingers.

This undermines the'retail consumption experience'and deters repeat purchase.

Retail catering aside, general leisure, recreation and sport environments, such as picnic and camping, have similar requirements-of secure food wrap until (self) serving, and thereafter convenience of consumption and disposal Statement (s) of Invention According to one aspect of the invention, a carton, carrier, bag, or tray, derived from a 2-D sheet, is convertible between a (3-D) hollow enclosure,

{with juxtaposed wall panels}, and an open-face tray, with an upstanding peripheral rim, {of contiguous re-deployed wall panels}.

Certain constructions embody an intermediate, dispensing form, of in-turned, opposed longitudinal edge panels, of a rectangular 2-D sheet carton blank, overlying an intermediate portion, itself then folded transversely, end-to-end, to overlay outboard longitudinal edge portions, as a flattened, collapse-folded assembly.

Desirably, enclosure retention is by local bonding, between juxtaposed edge panels, severable for wall panel separation, and re- disposition to a tray rim.

Residual diagonal stub folds, in longitudinal edge panels, may be used as triggers for panel bending, upon erection to a 3-D form.

Desirably, wall panels are configured to promote upstand, upon erection to a 3-D form.

Thus relative panel widths, and differential tapered profiles-accommodated without distortion in a flat dispensing configuration-may be used to create panel, bending, bulging and upstand, when unfolding the overall structure into an erect 3-D form.

In a particular construction, a base panel is entrained with a wall panel, by intersecting folds, forming a re-entrant corner pocket; and with an opposite wall panel, also entrained with the base panel, by a diagonal fold intersecting a marginal stub fold, promoting wall panel bow, preparatory to panel (re-) assertion, into an erect form, with edge juxtaposition, of opposite wall panels.

Re-entrant nose tabs, with complementary slots, can be employed for end panel edge interfit.

According to another aspect of the invention, a tray is convertible into a carton, carrier, or bag, as an enclosure or wrap, and vice-versa; the tray comprising: a contiguous (2-D carton blank) sheet, subdivided into a plurality of juxtaposed panels, with intervening crease or fold lines, and bounded by an upstanding peripheral rim, with a collapsible corner fold joint, between side wall and base panels, to allow reversible erection and collapse.

Generally, a'convertible'carton-tray can be (quick) erected, say at a'point-of-sale' (counter).

In practical operation, preliminary erection to an open-top configuration-allows contents-fill.

The carton top is then closed (eg a top closure snapped shut) to envelop the contents.

The closed carton, with contents secure within, can then be taken to a'consumption' point, such as rested upon a table or counter.

The contents can be exposed by'transforming'or'converting'the carton,'beyond'an open condition, into an tray, with a peripheral upstanding (contents retaining) contiguous peripheral rim-ready for consumption.

Contiguity of the upstanding rim, through re-disposed wall panels, serves as a barrier to contents egress, or spillage, from the tray platform confines.

Once the contents have been consumed, the tray can also be used as a scoop and carrier for waste disposal-in doing so gathering together waste debris and detritus upon the tray.

With accumulated waste, the tray can either be left laid opened-out, or splayed apart, or reverted to a (3-D) carton enclosure.

Thus the contents remain in contact only with the internal carton-tray surface.

Edge Rim Upstand Conveniently, the open tray form (at) embodies an upstanding (contiguous) peripheral (edge) rim, of sufficient depth to restrain contents laterally and'contain'spillage.

An edge rim also stiffens the overall structure-and supports an intervening flat panel base platform.

With an edge rim formed by inward folding of the base panel periphery, reliance is placed upon the fold integrity and residual material stiffness and resilience (ie spring back when displaced) to preserve the upstand.

Generally, the more'pronounced'the upstand, in relation to the base platform area, the stiffer the overall structure.

Otherwise, reversion of the edge rim towards the plane of the base panel reduces the panel stiffness-allowing bending, flex, flop and collapse under load.

The tray is envisaged as supported from underneath-as when deployed upon a support surface-rather than necessarily self-supporting, say from either or both ends - as would be the case when carried by hand.

Thus'hand carriage'is primarily the province of the closed carton, using dedicated integrated end handles, to keep the container closed and preserve its structural integrity.

Handles For ease of handling and closure, bespoke profiled handle elements are desirably integrated into opposed lid closure flaps.

Closure lid flap interlock is conveniently through handle interaction.

A unitary carton blank construction allows a'seamless'or contiguous (ie uninterrupted by cuts or slits) junction between tray walls and base.

Again, this ensures that no spilt contents, liquid or otherwise, can escape the tray confines.

Conversion from a tray to a carton enclosure requires'undermining'the stiffening edge rim.

This can b e achieved through the disposition of rim folds, in particular at mid-span.

Tuck-In Folds A re-entrant'tuck-in'corner (panel) fold features between carton or bag end walls and base.

Such tuck-in folds allow the tray to be folded about the middle, with residual upstanding rim portions preserved and brought together to form abutting or marginally overlapping end wall panels.

These end walls intervene between opposed side wall panels formed by the opposed ends of the tray base platform, a mid-portion of which forms a carton base separating the side walls.

In-turned corner (panel) folds can be deployed, in a snap-action, by interaction of carton end walls.

That is, adjoining panels are susceptible of (manual) bias displacement or deformation, between'stable'conditions, and attendant fold configurations.

Between those stable conditions is a region of fold reversal'instability'.

Some variation in mid-span, (tuck-in) rim-folding is admitted, to allow variation in (3-D) carton erection, as depicted in illustrated embodiments.

Dispenser Configuration Employment of a pre-folded intermediate'dispenser'configuration-between flat sheet carton blank and erect carton-facilitates brisk,'snap-action', self erection upon initiation of certain actions, including: grasping closure flap and handle ends together; depressing a base fold inward, between sidewalls extending between closure and base, and allowing those side wall panels to splay outward, to accommodate an intervening base; while opposed end walls at each end spring outward, respective end wall panel being joined via a localised tab bonding action.

Localised Bonding Localised bonding of end wall panels can be used to preserve the integrity of an erect 3-D form; at least until conversion to a tray format is required-whereupon the bonding can be severed.

Localised contact bonding of end walls obviates critical alignment juxtaposition of interfitting tabs and slots, for co-operative locking or latching interaction.

Conveniently, localised bonding is upon severable (eg'tear-off') elements (such as tabs), which, when severed and separated,'bypass'or disable the bonding, or bonding effect, and allow the enclosure to be opened out into a rimmed tray.

That is bonded elements remain bonded, but are disengaged from one of the elements they are holding together.

The bonding may be permanent-in which case a tear off release mechanism, such as pre-perforation of the bounding edge of a bonding tab, is required.

Alternatively, the bonding may be temporary-ie a tacky, pelable adhesive which can be prised apart upon applying sufficient, appropriately-directed, localised separation force.

Reversion-from the tray to the enclosure-is feasible, albeit not with the integrated 'retention'security ; rather reliance is placed upon, say, gripping together opposed ends, forming closure flaps, with optional handle features or profiling.

Again when the carton is opened into the tray format, an upstanding, contiguous, peripheral rim is advantageous for contents display, access and selective consumption-particularly in the case of a fast food carrier.

Impermeable A moisture-resistant, impervious or impermeable material or coating is desirable for the carton or bag material-such as, a coated (eg lacquered or impregnated) flexible card.

This preserves carton (eg card) material integrity against inadvertent liquid spillage, contact with which might otherwise soak the material and allow it to disintegrate.

Moisture-proofing can also contribute to desired material stiffness and resilience- promoting a snap folding action.

Embodiment (s) There now follows a description of some particular embodiments of carton carriers and carton trays according to the invention, by way of example only, with reference to the accompanying diagrammatic and schematic drawings, in which: Figures 1 through 10 show a collapsible carton carrier derived from a unitary, sheet form, carton blank.

More specifically: Figure 1 shows a carton blank for a carrier carton Figure 2 shows an initial fold sequence of the carton blank of Figure 1, with longitudinal opposed edges folded inward; Figure 3 shows subsequent folding step to that of Figure 2, in which opposed ends are brought together, about a central transverse crease, to create a flat-pack pre- folded collapsed (carrier) carton form; Figure 4 shows in an initial stage in erection of the collapsed carton of Figure 3, in which opposite side walls are splayed apart by inward depression of an end face (containing a central transverse fold, which is opened out by this action), while holding an opposite handle end closed ; Figure 5 shows a final erection stage for the carton of Figures 1 through 4, in which a base end sits square to alternating spaced opposed side and end walls, whilst an opposite handle end remains closed ; Figure 6 shows the carton of Figure 5 with its top handle end opened by pulling apart opposed handle portions entrained with respective side walls ; Figure 7 shows a latched or indexed condition of the top-opened carton of Figure 6, in which opposed end walls are interlocked;

Figure 8 shows a (top end) closed condition of the latched carton of Figure 7; Figure 9 shows a translucent version of the top closed latched carton of Figure 8; Figure 10 shows an opened out, disassembled, version of the carton of Figures 1 through 9-effectively a marginally collapsed or peripheral edge rim in-turned variant condition of Figure 1; Figures 11 through 19 show a variant collapsible carton carrier to that of Figures 1 through 10, derived from a unitary, sheet form, carton blank.

Thus, more specifically : Figure 11 shows a laid flat carton blank, sub-divided by a matrix of cuts, creases and folds; Figure 12 shows an initial erection fold step for the carton blank of Figure 11, by in- turning opposed longitudinal edges; Figure 13 shows a concluding fold step about a central crease, to achieve a collapsed flat-pack carton form, ready for erection, through the erection sequence of Figures 14 through 19; Figure 14 shows an initial erection stage from the collapsed form of Figure 13, by opening out opposed side walls along respective creases about a central transverse fold; Figure 15 shows a follow-on erection step from that of Figure 14, by outwardly turning the peripheral side edges of the upstanding side wall, creating a tucked in corner edge fold at the juncture with the laid dormant or prostrate opposite side wall and attendant upturned opposed side edges; Figure 16 shows a follow-on erection step from Figure 15, in which the formerly prostrate side wall, and attendant opposite side edges, is folded about a respective

intermediate crease outboard of the central transverse crease and brought into opposition with the upstanding side wall, but with a different tucked in corner edge fold ; Figure 17 shows the conclusion the Figure 16 step to achieve an assembled, top- open carton, with side edges interlocked, through a'cut and tuck', edge tab and slot feature ; Figure 18 shows the assembled open-top carton of Figure 17 with top handles splayed apart; Figure 19 shows the assembled carton of Figures 17 and 18, with top handles closed together over the carton mouth; Figures 20 through 27 show a collapsible carton tray, derived from a unitary, sheet form, carton blank; Thus, more specifically : Figure 20 shows a laid flat carton blank, sub-divided by a matrix array of cuts, folds and creases, ready for erection; Figure 21 shows the flat carton blank of Figure 20 (pre-) folded into a marginal edge in- turn or upstand, to create a shallow, bounded tray configuration; Figure 22 shows an initial erection step for the carton of Figures 20 and 21, by in- turning of one end over an intermediate fold about a central transverse fold, leaving a marginal peripheral edge as an upstand, and creating a preliminary tuck-in, or inset corner fold, to accommodate the transition in upstand orientation; Figure 23 shows a subsequent step to that of Figure 22, with corner edge in-turned fold completed ; Figure 24 shows a follow-on step to that of Figure 23, with repetition of the Figure 22

step to create opposed side walls, with respective marginal peripheral upstands together creating intervening end walls, leaving upper upstanding closure flaps; Figure 25 shows inward folding of one of the closure flaps of Figure 24; Figure 26 shows a follow-on closure step to that of Figure 25, with inward folding of the other closure flap and interlock of opposed closure flaps through a tab and slot configuration; and Figure 27 shows a concluding closure step to that of Figure 26, in which interlocked closure flaps are collapse folded upon the erect container, to create an end closure panel and central interlocked tab and slot handle upstand; Reversal of the erection and closure sequence of Figures 22 through 27 converts the container into a bounded shallow tray, as depicted in Figure 21, thereby fully exposing-and so allowing ready access to-container contents; Figures 28 through 37 show a carton carrier variant, somewhat similar to that of Figures 1 through 19, but with a more elaborate outboard longitudinal edge profile, to afford co-operative end wall panel interfit and interlock, over a marginal edge overlap ; Thus, more specifically : Figure 28 shows an unfolded carton blank, with profiled opposed longitudinal edges, to define interlocking tabs upon erection and co-operative interfit of end wall panels; Figure 29 shows a (minor) variant of the carton blank of Figure 28, with provision of locking tabs for opposed top panels, upon carton erection and top closure ; Figure 30 shows an initial folding step for the carton blank of Figure 28, in which opposite longitudinal edge panels are turned inward, to overlie an intermediate mid- panel defining opposed side wall panels and intervening base panels in an erect carton;

Figure 31 shows a subsequent folding step to that of Figure 30, in which the pre- folded carton blank is folded end-to-end about a transverse central fold, to create a pre-collapsed (stacked) storage and'dispensing'carton configuration, ready for quick- erection; Figures 32 through 34 show one possible (quick) erection sequence for the dispensing carton configuration of Figure 31; Thus, more specifically : Figure 32 shows an initial erection step, in which opposed carton wall panels are separated, by depressing the folded base into an intervening condition, whilst holding opposite top handles closed together; Figure 33 shows an intermediate follow-on step to that of Figure 32, in which a generally rectangular outward form has been assumed, but in which juxtaposed end- wall panels are still somewhat inwardly turned, as their respective profiled edges co- operatively interfit and internest; Figure 34 shows a final erection step to that of Figure 33, in which co-operatively interlocked and interfitted end wall panels assume collectively opposed end faces; Figures 35 through 37 show an alternative erection sequence to that of Figures 32 through 34; Thus, more specifically: Figure 35 shows an initial erection step, corresponding to that of Figure 32, but allowing an alternative ultimate end wall panel co-operative interfit and interlock; Figure 36 shows a follow-on erection step, corresponding to that of Figure 33, but again allowing an alternative end wall panel co-operative interfit and edge interlock ; Figure 37 shows an erected rectangular outward carton form, corresponding to that of

Figure 34, but with an alternative end wall panel co-operative interfit and edge interlock; Figure 38 though 49 show yet another carton-tray variant, with opposed profiled longitudinal carton blank edges, to promote interfit and interlock of end wall panels in an erect carton; Thus, more specifically : Figure 38 shows a laid flat carton blank ; Figure 39 shows initial in-turning of one longitudinal marginal side edge strip of the carton blank of Figure 38; Figure 40 shows in-turning of the opposite longitudinal marginal side edge strip to that of Figure 39; Figure 41 shows initial transverse folding of the pre-folded carton blank of Figure 40, to form a mid-section concertina step fold, at a formative carton base; Figure 42 shows conclusion of the transverse mid-span folding of Figure 41, to form a pre-collapsed, flat-pack carton format, ready for storage, stacking (not shown) with other such flat-packs and dispensing; Figure 43 shows an initial stage in erection of the flat-pack carton of Figure 42, by squeezing opposed top and bottom ends, whilst holding the top end closed, to allow the bottom end to splay open, with tucked-in end walls brought outward; Figure 44 shows an erect, 3-D carton, with opposed end walls deployed, and the top remaining closed; Figure 45 shows the erect carton of Figure 44, but with the top open, by allowing opposed top panels and attendant handle tabs to part;

Figure 46 shows an initial stage in (dismantling) conversion of the erect carton of Figure 45, by pulling apart opposed side walls ; Figure 47 shows a final conversion stage to that of Figure 46, into an open, shallow tapered side format, suitable for exposing and gaining access to carton contents- such as when used in a so-called'fast-food'serving environment; Figure 48 shows an optional opposed end wall interlocking closure step-which might follow the preliminary erection stage depicted in Figure 44-of depressing a bottom tab inward, so that its upper (rounded) nose profile is inserted between opposed end wall panels, themselves with their respective edge profiles interlocked; Figure 49 shows a final end wall interlocking closure stage to that of Figure 48; Figures 50 through 61 show a variant of Figures 38 through 49, with edge interfit and interlock refinement; Thus more specifically : Figure 50 shows a laid flat carton blank ; Figure 51 shows initial in-turning of one longitudinal marginal side edge strip of the carton blank of Figure 50; Figure 52 shows in-turning of the opposite longitudinal marginal side edge strip to that of Figure 51; Figure 53 shows initial transverse folding of the pre-folded carton blank of Figure 52, to form a mid-section concertina step fold, at a formative carton base; Figures 54 and 55 shows conclusion of the transverse mid-span folding of Figure 53, to form a pre-collapsed, flat-pack carton format, ready for storage, stacking (not shown) with other such flat-packs and dispensing;

Figure 56 shows an initial stage in erection of the flat-pack carton of Figures 54 and 55, by squeezing opposed top and bottom ends, whilst holding the top end closed, to allow the bottom end to splay open, with tucked-in end walls brought outward; Figure 57 shows an erect, 3-D carton, with opposed end walls deployed, and the top remaining closed; Figure 58 shows opposed end wall interlocking closure by interfit of juxtaposed end wall panels along their respective profiled edges and inward tucking therebetween of an upper profiled nose of an upturned, outer-lying, base flap; Figure 59 shows the erect carton of Figure 57, but with the top open, by allowing opposed top panels and attendant handle tabs apart; Figure 60 shows an initial stage in (dismantling) conversion of the erect carton of Figure 59, by pulling apart opposed side walls ; Figure 61 shows a final conversion stage to that of Figure 60, into an open, shallow tapered side format, suitable for exposing and gaining access to carton contents- such as when used in a so-called'fast-food' (serving and consumption) environment; Figures 62 through 88 show a further carton carrier variant, with localised bonding of the end wall panels.

Thus, more specifically : Figure 62 shows a carton blank for a collapsible carton, sub-divided by a matrix array of cuts, creases and folds; Figure 63 shows an initial fold sequence of the carton blank of Figure 62, with longitudinal opposed edges folded inward; Figure 64 shows initial stages in a subsequent folding step to that of Figure 63, in which opposed ends are brought closer together, about a central transverse crease;

Figure 65 shows joining of opposite longitudinal edge/end wall panels by ('permanent') contact adhesive bonding; Figure 66 shows a'flattened'carton, folded about a central transverse crease, to create a flat-pack pre-folded collapsed dispenser (carrier) carton form-suitable for stacked dispensing with other such pre-folded carton forms; Figure 67 shows an initial stage in erection of the flat-pack carton of Figure 66, inward depression of a (base) end face (itself incorporating a central transverse fold, which is opened out by this action), and inward depression of lid closure panels, while holding opposite handle portions together, causes opposite side walls to splay apart; Figure 68 shows a subsequent stage in carton erection, in which base panel is almost fully deployed; Figure 69 shows a carton at the same stage of erection as Figure 68, the same end wall is shown viewed from the other side; Figure 70 shows a still further stage in carton erection to that depicted in Figures 68 and 69 (viewed from the same side as Figure 68), continued inward depression of opposed handle ends of lid closure panels,'snaps'opposite end wall panels into an erect configuration-certain hidden detail is shown in dotted lines; Figure 71 shows a carton at the same stage of erection as Figure 70, showing the same end wall, viewed from the other side-certain hidden detail is shown in dotted lines ; Figure 72 shows a final erection stage for the carton of Figures 62 through 71, in which the base end sits square to alternating spaced opposed side and end walls, whilst an opposite handle end remains closed-certain hidden detail is shown in dotted lines; Figures 73 through 77 show part cut-away side elevations, along line A-A'in Figure 72, of a carton in various stages of erection.

Thus, more specifically: Figure 73 shows a part cut-away, side elevation of a carton folded into the pre- dispensing configuration of Figure 66; Figure 74 shows a part cut-away, side elevation of the initial stage in erection of the flat-pack carton of Figure 73, corresponding to the perspective views of Figures 68 and 69; Figure 75 shows a part cut-away, side elevation of a further stage in carton erection to that depicted in Figure 74; Figure 76 shows a part cut-away, side elevation of a still further stage in carton erection to that depicted in Figure 75, corresponding to the perspective views of Figures 70 and 71; Figure 77 shows a part cut-away, side elevation of an erected carton, corresponding to the perspective view in Figure 72; Figures 78 through 82 show fragmentary sectional, plan, cut-away views, along line B- B'in Figure 72, of an end wall in various stages of carton erection; Thus, more specifically: Figure 78 shows a fragmentary sectional, plan, cut-away view of a carton end wall folded into the pre-dispensing configuration of Figure 66; Figure 79 shows a fragmentary sectional, plan, cut-away view of a carton end wall in the initial stage of erection from the flat pack carton form of Figure 78; Figure 80 shows a fragmentary sectional, plan, cut-away view of a carton end wall in a further stage of carton erection to that depicted in Figure 79; Figure 81 shows a fragmentary sectional, plan, cut-away view of a carton end wall in a

still further stage of carton erection to that depicted in Figure 80, and corresponding to the stage of carton erection depicted in Figure 75; Figure 82 shows a fragmentary sectional, plan, cut-away view of a carton end wall in the erect carton, as depicted in Figures 72 and 77; Figure 83 shows the erect carton of Figure 72 with top (handle) end open, by allowing opposed top panels and attendant handle portions apart; Figure 84 shows a closed carton with entrained handles at an initial latching stage; Figure 85 shows a closed carton with handles latched; Figure 86 shows an initial stage in conversion of the erect carton of Figure 85 into a tray configuration-top handle end is opened and pulling apart of opposed handles separates (previously locally bonded) longitudinal edge/end wall panels, along pre- perforated tabs; Figure 87 shows an opened out, disassembled, version of the carton of Figures 62 through 86-in a tray configuration; Figure 88 shows in-turn and capture of handles on the lid panels, to create an upstanding, contiguous, peripheral rim around the base and side wall panels.

Figures 89 through 102 show a further carton carrier variant, with localised bonding of the end wall panels, to that depicted in Figures 62 through 88.

Thus, more specifically : Figure 89 shows a carton blank for a collapsible carton, sub-divided by a matrix array of cuts, creases and folds ; Figure 90 shows an initial fold sequence of the carton blank of Figure 89, with longitudinal opposed edges folded inward;

Figure 91 shows initial stages in a subsequent folding step to that of Figure 90, in which opposed ends are brought closer together, about a central transverse crease; Figure 92 shows joining of opposite longitudinal edge/end wall panels by ('permanent') contact adhesive bonding; Figure 93 shows a'flattened'carton, folded about a central transverse crease to create a flat-pack pre-folded collapsed dispenser (carrier) carton form-suitable for stacked dispensing with other such pre-folded carton forms; Figure 94 shows an initial stage in erection of the flat-pack carton of Figure 93, inward depression of a (base) end face (itself incorporating a central transverse fold, which is opened out by this action), and inward depression of lid flap closure panels, while holding opposite handle portions closed, causes opposite side walls to splay apart; Figure 95 shows a subsequent stage in carton erection, in which base panel is almost fully deployed ; Figure 96 shows a final erection stage for the carton of Figures 89 through 95, in which the base end sits square to alternating spaced opposed side and end walls, whilst an opposite handle end remains closed ; Figure 97 shows the erect carton of Figure 96 with top (handle) end open, allowing opposed top panels and attendant handle portions apart; Figure 98 shows a closed carton with entrained handles at an initial latching stage; Figure 99 shows a closed carton with handles latched; Figure 100 shows an initial stage in conversion of the erect carton of Figure 99 into a tray configuration-top handle end is opened and pulling apart of opposed handles separates (previously locally bonded) longitudinal edge/end wall panels, along pre- perforated tabs;

Figure 101 shows an opened out, disassembled, version of the carton of Figures 89 through 100, in a tray configuration; Figures 102 shows in-turn and capture of handles on the lid panels, to create an upstanding, contiguous, peripheral rim around the base and side wall panels.

Description Referring to the drawings, variant carton configurations and attendant carton blank to carton erection sequences are depicted.

Carton collapse, post-erection is essentially a reversal of the carton erection sequence.

Terminology-Fold vs Crease Again, for convenience, the terms crease and fold are used somewhat interchangeably on occasion.

Strictly, a crease may be regarded as preparatory to creating a fold, or a fold action may be used to create a permanent crease, which thereafter defines a fold line or a predisposition to fold about a line.

A crease may be created by an impression tool, such as a (flattened or blunted) blade edge, applied from one side, against an opposed platen, in a die cutter.

Resistance to folding may be reduced by incorporating perforations or slits, through the local material depth, along a crease or fold.

In extreme cases, the fold may comprise a series of residual'tether'fragments (eg spikes, stubs or tabs) of material bridging the fold, and lowering the fold energy or engendering high predisposition to fold.

Scoring from one other (or indeed) both sides, may also be used locally to weaken

material and promote fold action along the score line.

Absent some pre-weakening, or severance of card pulp fibres, folding is unpredictable.

Thus the material may start to flex and bow and may suddenly collapse, creating a crease or kink.

Behaviour-Consistency & Predictability Although the carton art is well-developed, it remains somewhat of a blend of art and science in achieving consistent, predictable behaviour of a card material.

Thus material production characteristics may vary from specification and under varying conditions, such as of ambient temperature and moisture.

Moreover, post-production processes, such as surface printing can impact upon subsequent behaviour.

User expectations of a quick-erect carton are a low, (virtual zero) failure rate, without exercise of special manipulative skills.

Translating a one-off manually crafted version into a production ready form is fraught with difficulty.

Subtleties of geometry and dynamics of loaded material are contributory factors- difficult to model, except by empirical trial and error.

Carrier-Carton The cartons of Figures 1 through 19, one variant of which is depicted in Figures 1 through 10, and another variant of which is depicted in Figures 11 through 19, are configured and intended primarily as contents enclosure or wrap for transport and storage.

That said, a marginal peripheral fold edge is evident in the carton blank-which could be deployed to create a shallow tray configuration, with an upstanding rim bounding a base platform.

Transition of the rim from longitudinally to transversely of the base is accommodated by tuck-in corner folds.

The carton variant of Figures 28 through 37 can similarly be regarded-the difference being essentially one of a more'positive'co-operative end wall panel interfit and edge interlock-in turn affording more continuous or intact collective wrap-around and so secure (contents) enclosure.

Hence their informal designation as'carrier-cartons'.

Moreover, the carrier cartons of Figures 1 through 19 and in turn Figures 28 through 37, feature a common pre-folded, flat-pack, (pre-) collapsed'dispensing'mode-that is a mode allowing mutual stacking and yet ready for erection, contents-fill, and (top) closure.

Thus, the respective carton blanks of Figures 1 and 11 are essentially similar in central 'base'fold configuration, but differ in outer closure treatment.

Convertible Tray Carton The carton variant of Figures 20 through 27 is configured to allow ready (reversible) conversion to and from, a relatively shallow tray form.

Hence the informal designation'tray carton'or'carton tray'.

A similar top panel closure fold configuration is employed in Figures 1 and 20, albeit with departures in handle profile.

Thus abutting loops feature in Figure 1 and interlocking tab and slot in Figure 21.

However, a pre-folded collapsed dispensing mode is not featured in this particular variant.

This allows a somewhat less sub-divided (ie by creases or folds) central base panel configuration.

Carrier Carton Tray Later carton variants of Figures 38 through 102 feature both a flat-pack dispensing mode, conversion to carrier carton and subsequent opening to a tray configuration- say for contents exposure, access, serving, or consumption.

The carton variants of Figures 62 through 102 are configured such that end wall panels are locally bonding or jointed, in the flat pack dispensing mode, to ease carton erection by ensuring co-operative end wall interfit.

In addition, in the open tray configuration, capture of the handles in slots on the lid panels maintains an upstanding, contiguous, peripheral rim.

Referring to Figures 1 through 10: In the carrier carton of Figures 1 through 10, a 2-D carton blank 20 is sub-divided by a largely rectangular and bifurcating diagonal matrix array of intersecting folds, into a series of panels, which serve as side walls, end walls, base and top closures in an erected carton assembly, of Figures 5,8 and 9.

More specifically, opposed longitudinal edge panels 22,23 bound an intermediate or mid-panel 24, through associated longitudinal (edge) creases or folds 32,33.

A central, or mid-span, transverse fold 34 is bordered by relatively offset, inboard transverse folds 35,36, defining opposite bottom edges of an erected carton assembly.

Similarly, outboard transverse folds 37,38, at the outward ends of the carton blank 20, define opposite top edges of an erected carton assembly.

Bounded by corresponding bottom and top edge folds 35,37 and 36,38 are opposed side wall panels 43,44 respectively.

Adjoining bottom panels 41,42 are defined respectively between bottom corner edges 36,35 and central transverse fold 34.

Top (opposed closure) panels 45,46 are defined respectively between top (fold) edges 37,38 and associated handles 27,28.

Interposed between longitudinal edge panels 22,23 and top panels 45,46 are (outer) corner folds 51, 53,55 and 57, disposed in associated triangular corner pieces 71,73,75,77.

The corner folds 51,53,55 and 57 can be linear, but are shown as of (sharply) tapered or wedge profile, to promote readiness of folding for carton erection.

Bounding the adjoining base panels 41,42 are paired diagonal folds 61,62 and 63, 64-together forming'tuck-in' (inboard) apexes, in respective longitudinal edge panels 22,23.

In the initial folding step, depicted in Figure 2, the laid flat 2-D carton blank of Figure 1 is converted into a pre-folded, multi-layered carton, with opposite longitudinal edge panels 22,23 inwardly turned about their respective longitudinal edge folds 32,33.

Outboard portions of the longitudinal edge folds 32,33, form corner edges between opposed side walls and intervening end walls of the erected carton, as depicted in Figures 5,8 and 9.

Inboard portions of those same longitudinal edge folds 32,33 form bottom edges of the erected carton.

In the transition from the initial folded carton blank of Figure 2 to the pre-folded collapsed, ready-to-dispense, multi-layer configuration of Figure 3, the carton is folded about the central transverse fold 34, to bring the opposite handle ends 27,28 into mutual overlaid juxtaposition.

Similarly, the corresponding opposed base panels 41,42, side wall panels 43,44 and top panels 45,46 are brought into mutual overlaid juxtaposition.

The corresponding outboard portions of each of the longitudinal edge panels 22,23 are also mutually overlaid and sandwiched in between the base, side and top panels 41/42, 43/44 and 45/46.

In order to erect the pre-folded collapsed dispensing form of Figure 3, the opposed side walls 43,44 are'allowed'to spring apart somewhat, under the resilience of the longitudinal folds 32,33, which biases the longitudinal edge panels 22,23 into an upstand from the contiguous base, side and top panels 41/42, 43/44 and 45/46.

Panel 22,23 upstand is continued by a'positive'erection bias attributable to panel contiguity as the carton base is first flattened and end walls are formed from outboard portions of the panels 22,23.

Thus, an applied displacement force, indicated by arrow 100 on Figure 4, directed upon the base centre fold 34, tends to drive-and reverse-the centre fold 34 in between the bounding fofds 35,36.

This action can be achieved by, say, pressing the centre fold 34 of the pre-folded assembly of Figure 3 downward on to a reaction surface, such as a worktop or between the palm of the hand, while grasping the opposite top handle end.

In doing so, adjoining base panels 41,42 are splayed outwardly, until they lie eventually co-planar-whereupon they collectively constitute a generally flat base platform, as depicted in Figures 5 through 9.

The longitudinal edge panels 22,23 remain individually contiguous material strips, but

are segmented into corresponding outboard panels, about the transverse centre fold 34, to form opposed paired end wall portions.

Opposed paired end wall portions are'asserted'as an upstand from side panels 43, 44 and intervening central portions transfer a contributory bottom panel 41,42 displacement reaction.

Carton Bottom or Base Platform Upon outward turning, or unfolding of end walls into paired juxtaposition, residual longitudinal edge panel central portions remain in-turned, as intervening inboard bottom corner joints.

These inboard corner'joints'deploy co-operatively paired inboard diagonal folds 61, 62 and 63,64.

Thus the diagonal fold 62 is turned inward-as a tuck-in corner portion.

An outboard corner segment 162, between the centre fold 34 and the diagonal fold 62, is overlaid by an inboard corner segment 262 of complementary profile disposed at the opposite (inner) side of the diagonal fold 62.

This allows a residual outboard portion of the longitudinal edge 22 constituting an end wall portion to upstand in relation to both contiguous side wall panel 44 and base panel 42.

The companion diagonal fold 61 is reverse-turned in relation to fold 62, being outwardly exposed at the bottom end wall of the assembled carton, as shown in Figures 5 through 9.

An outboard corner segment 161, between the centre fold 34 and the diagonal fold 61 is thus overlaid upon an inboard corner segment 261 upon the opposite side of the diagonal fold 61.

This allows the juxtaposed end panels, constituted by opposite outboard ends of common longitudinal edge 22, marginally to overlap-with a curved profile edge tuck slit 98, shown operative in Figures 7 through 9.

Such overlap preserves carton enclosure continuity-avoiding unsightly and dysfunctional gaps.

A similar interaction follows with corresponding paired diagonal folds 63,64-and curved profile edge tuck slit 99-on the opposite side of the carton.

Carton Top Similarly, at the carton top, outboard diagonal corner folds 51,53,55,57 define outboard corner joints, accommodating contiguous material'transition'between longitudinal edge panels 22,23 and top panels 45,46.

Effectively the folds 51,53,55,57 sub-divide, segment-and further triangulate-the associated triangular outboard corner portions 71,73,75,77, allowing co-operative in-turning or collapse.

The longitudinal edge panels 22,23 can thus be brought to upstand from the intermediate panel 24-and'derivative'side and top panels 43,44 and 45,46.

This careful and crucial disposition of diagonal folds, for corner joints, is contrived (semi-) automatically, in an erection sequence taking in the intermediate collapsed dispensing state of Figure 3.

Thus, by: initially preserving the handle closure-say by grasping between fingers and thumb of one hand; and 'containing'the opposite base end-say within the palm of the other hand;

whilst slightly depressing the carton base inward against the carton top, gripped by the handle; the opposed side walls tend to splay outward, as a base platform emerges from the reverse-folding and in-turning of originally out-turned base panels.

The outcome is a'gable-top'carton with flat base, as shown in Figure 5.

The carton top can then be opened, by pulling apart the handles, as shown in Figures 6 and 7.

End wall latching-through enabling of the tuck 98-is shown in Figure 7.

The carton can then be (re) closed, by pulling together and depressing the handles, and collapsing opposed top panels 45,46, about respective junction folds 81,82 with handles 27,28, to create a flat top carton closure, as shown in Figures 8 and 9.

If the carton is then opened out, the carton blank assumes a residual folded configuration, as shown in Figure 10.

Whilst this is somewhat tray like-with a shallow inclined peripheral edge upstand-it is not intended primarily to be the convertible tray of Figure 21.

Whilst the assembly and collapse sequence may be repeated to allow re-use-the sheet (card) material tends progressively to'tire'somewhat-as the folds lose their body or resilience.

The folds and panel transition may require certain manual'guidance', containment or restraint, in order to assume their intended relative disposition, orientation and operative sequence.

With certain exceptions, the fold disposition and role of the other carrier carton embodiment of Figures 11 through 19 corresponds generally to that of Figures 1 through 10.

However a somewhat simpler handle format-without attendant (top) closure panels, and omitting the outboard corners and diagonal folds-is employed.

A double-notched latch profile is employed, in order to entrain marginally overlapping end walls in the erected carton.

Otherwise that embodiment will not be described in detail.

Similarly, to a large extent, with the convertible carton-tray embodiment of Figures 20 through 27, except again for a somewhat'simplified'carton blank format-given the absence or omission of an intermediate pre-folded collapsed dispensing mode.

Top closure panels and attendant outboard corners and diagonal folds are employed, but the base is not sub-divided.

The junction between end walls and base is accommodated by spaced diagonal folds, with no overlap, but rather direct abutment, between end wall panels.

The carton carrier of Figures 28 though 37 embodies bespoke profiled opposed longitudinal carton blank edges, to define interlocking edge tabs and slots or slits.

Thus, along one longitudinal edge, a rounded nose tab 131 is defined at one end, to locate, upon carton erection and assembly, into a corresponding curved slit 132 at the opposite end, alongside an elongate tab 135.

A corresponding rounded tab 133, curved slit 134 and elongate tab 137 are disposed upon the opposite longitudinal edge of the carton blank.

Co-operative edge interfit and interlock of the various rounded nose tabs, 131,133, curved slits 132,134 and elongate tabs 135,137 is shown in Figures 33,34 and 36, 37.

Broadly, the objective is to achieve a more continuous end wall configuration and resist any tendency for the end wall panels to buckle inwardly together.

Referring to Figures 38 through 49, a convertible tray carton is configured with a facility for (pre-dispensing) flat-pack.

To this end, the carton blank 330 employs a bespoke opposed longitudinal edge profile, with re-entrant nose tabs 337 at opposite ends and a mid-span double taper wedge fold 339.

The re-entrant nose tabs 337 embrace respective slots 341, for receiving the tabs at the opposite end, when those ends are folded into mutual juxtaposition, upon carton erection.

The tapered-wedge, double, twin or paired folds 339 provide a bias or impetus for promoting base flap emergence.

Thus the triangular panels lying immediately adjacent, but at opposite sides of, those wedge folds 339, are allowed to move and mutually overlie one another, in a carton fabric'roll (un) fold' action over the fold.

Snap Action This same'roll (un) fold' action, along with the inherent material resilience imparts a certain over-centre, snap-action to carton flap deployment.

This'snap-action'is preserved through repeated use-at least until the material becomes'tired'or'fatigued', through (excessive) over-repetitious use.

In the case of paper or card, such tiredness or wear arises from crushing of internal pulp fibres.

Coating, immersion or impregnation of the paper or card with a wax or varnish, or laminating with a plastics layer, may delay the onset of material fatigue.

In that regard, plastics sheet material may have a longer life, albeit at increased expense.

Triangular Base Flap Overall, the result of mid-span triangular panel segmentation and mutual folding and overlying, is: to form a triangular base flap, with its apex upstanding from the carton base, whilst peripheral entrained triangular panels-linking the base flap to the end wall panels-sit behind the base flap.

In effect, the intermediate triangular panels, linking the base flap and end wall panel flaps, are (mutually) overlaid upon corresponding triangular portions of the base flap.

In particular, base flaps at respective carton ends are lead to an'outward disposition'- that is overlying the associated end wall panels-upon: folding opposite ends of the carton blank together, and then allowing the base to splay, whilst holding the top panels and attendant handle tabs closed together.

In achieving a pre-collapsed, flat-pack, folded carton dispensing configuration, through successive mid-span transverse folding, as depicted in Figures 41 and 42, of doubled-up material layers 343,345, accumulates a certain stored'latent fold energy'.

This in turn imparts a pre-disposition to re-assert an unfolded condition-relied upon to achieve base erection as depicted in Figure 43.

Similarly, the juxtaposed end wall panel in-turned folding of the preliminary longitudinal edge folding step of Figure 40, imparts a pre-disposition to re-assert, assume and preserve and un-folded condition, as depicted in Figure 44.

A trigger to such end wall panel deployment, is the initiative of pulling the in-turned

base flap, as indicated by the direction arrow in Figure 43.

To some extent, base flap emergence may happen automatically upon allowing the bottom of the carton side walls to expand-whilst (temporarily) holding the top ends 'captive'together.

At that juncture, a slight inward squeeze-or'restraint'or containment upon erection- of the expanded bottom end into a truncated pyramid configuration, promotes emergence or out-turning of both base flap and end wall panel flaps.

Once out-turned, juxtaposed end wall flap panels are allowed marginally to overlap- with their respective edges internesting and interlocking through the complementary interfit of their respective re-entrant nose and slot edge profiles.

The triangular upstanding base flap, as depicted in Figure 44, may simply be allowed to overly the interfitted end wall panels.

There is a slight risk of contents exposure, but the doubled base end fold-that is between upstanding triangular base flap and the carton floor or bottom itself-imparts a positive upward and inward bias, itself tending slightly to deflect the overlapping end wall panels inwardly.

Thus inadvertent contents exposure, or even emergence-if, say, the carton is abruptly displaced-is resisted.

To counter this possibility, the nose of the base flap can be tucked inward, to engage and inter-link with the end wall panel edge interfit, as depicted in Figures 48 and 49.

Figures 50 through 61 depict a refinement of the collapsible and convertible tray carton of Figures 38 through 49-in particular in relation to automated erection and end wall interlock.

To that end, the paired diagonal tapered double folds 339 forming an inward apex at mid-span are replaced by spaced transverse tapered double-folds 348,349 at the

juncture between side wall panels and base panel.

The paired folds taper to a common apex at the bounding fold edge of the in-turned longitudinal edge flap.

The outward taper thus terminates at the free, albeit in-turned, longitudinal edges.

The tapered double-folds are'loaded'upon the repeated transverse fold actions 343, 345, as depicted in Figures 53 and 54, forming a slight upstanding pocket, pleat or gather, with an informal crease defined between the primary folds.

This pocket pleat allows the fold orientation to reverse upon deployment of the end wall and base panels, as depicted in Figure 56.

Another effect of the pocket pleats is to impart a more effective, positive,'snap-action' roll fold or unfurl action, as the relative orientation of side walls is changed upon erection of the pre-collapsed, flat-pack, dispensing form, as depicted in Figure 56.

The longitudinal edge profiling of the carton blank embodies not only re-entrant nose tabs and slots for the end wall panels, but dedicated slots for the noses of the upturned base panels.

This supplementary feature imparts a more'deliberate'base flap tuck-in action, so that its nose engages a bespoke slot in juxtaposed end wall panel edges, upon erection into a 3-D carton form, as depicted in Figure 58.

To this end, a less round and more abrupt base nose taper is tenable, rather than, say, the rounded profile of Figures 38 through 49.

Generally, positive entrainment of base flap and end wall panels preserves the erect carton integrity upon opening the carton top, as depicted in Figure 59.

It follows that a more deliberate disengagement of base flap and end wall panels is required to preface conversion of the erect, (but top-open) 3-D carton form into a

shallow tray, as depicted in Figure 61.

+++ Preferred Variant Figures 62 through 88 illustrate a preferred variant form exhibiting further refinements to, and certain departures from, the collapsible and convertible tray carton configurations of Figures 38 through 61.

In particular, the carton blank features alternative folding/creasing, local end wall bonded jointing and an upstanding, contiguous, peripheral rim in the tray configuration.

The alternative crease or fold configuration is depicted in Figure 62. More specifically, a carton blank 410 includes: a wide central transverse crease (or marginally-spaced double crease) 455. asymmetrical single or individual diagonal folds 412,413, at opposite ends of the carton base 411, run from outboard ends of central transverse crease 455 to outboard ends of (shorter) offset, inboard transverse creases 428,427- thereby intersecting base end panels 430,429 respectively; short single or individual diagonal (stub) folds 414,419 extend from the inboard end of single folds 412,413, into longitudinal edge panels 424,426; these folds serve as a trigger for associated panel bending curvature, as described later; unlike the corresponding regimented parallel folding of other variants, in this case, single diagonal folds 421 and 422, in longitudinal edge panels 423, 425, are orientated slightly inclined to single folds 412,413 respectively; single diagonal folds 415,416,417,418, at the base end of longitudinal

edge panels 423,424,425,426 respectively, begin at the outboard ends of the offset, inboard transverse folds 427,428, and are inclined towards the central transverse fold 455; In co-operative disposition and action these various folds allow'snap-action' deployment of end wall panels upon carton erection, from an intermediate, pre- folded, dispensing configuration.

To ensure correct alignment and location of end wall panels upon carton erection, and to minimise manual handling interactions, end wall panels are bonded together prior to erection.

Bonding may be permanent, with perforated release mechanism, as depicted, in Figures 62 and 86, or temporary (not illustrated), such as with a tacky, pelable adhesive, thereby allowing the carton to be re-erected and re-used.

In practice, the adhesive agent used may be such that, upon prising apart, a surface layer is torn away and carried as a residual barrier to inhibit ongoing tackiness.

This is helpful for hygiene considerations, to avoid entrainment of dirt or food debris with the carton.

The longitudinal edge panels 423,424,425 and 426, form the end walls in the erect carton, and are configured such that (perforated) elements 433,434, overlie (bonding) elements 446,445 respectively, when folded into the pre-dispensing flat pack-as depicted in Figures 64 through 66.

Bonding agent may be applied to either or both elements of each joint.

As with the other variants the carton is constructed from a unitary carton blank.

(Pre-) Dispensing Flat Pack In order to facilitate'snap-action'erection, say, at point of sale or use, the carton is

folded and transformed into a pre-dispensing flat pack for storage, it is at this point that bonding of the end walls occurs.

In the initial folding step, depicted in Figure 63, longitudinal edge panels 423,424, 425,426, with respective bonding elements 446,433,445,434, and base end panels 429,430 are in-turned about longitudinal edge folds, to overlie side wall panels 453,454 and base panel 411.

The carton is then folded about central transverse fold 455, to bring opposite handle ends 457,458 into mutual overlaid juxtaposition.

The central transverse fold 455 is somewhat'thicker or deeper'than all the various other folds employed in the carton.

In production, using die cutter tooling, this'opposite' (sense) fold is achieved with a tool pressed onto the blank from the opposite (out) side, to (all) other folds/creases on the blank.

Ideally, this is undertaken without having laboriously to re-orientate or overturn the blank in the tool.

The significant'depth signature'of fold 455 (compared to the other'slim'folds) is such that it could be regarded as twin marginally (say, 2/3mm) spaced folds.

Moreover, the other folds may selectively incorporate multiple perforation slits (vis alternating slits and retention tabs)-effectively to promote fold action, by reducing the length of material subject to folding.

It is intended that in the (pre-) dispensing folded configuration of Figure 66 the depth of fold 455 accommodates the total overlaid material depth and so protects other base panel folds from unnecessary compression before carton erection.

Once folded into the (pre-) dispensing configuration, (perforated) elements 433,434, overlie (bonding) elements 446,445 respectively, and are bonded together-this may

be assisted by the application of pressure about the bonding joint.

It is intended that the carton is stored in this pre-folded, ready to dispense, configuration, as depicted in Figure 66.

Erection from Dispensing Form In order to erect the carton from the dispensing form, force or pressure is applied at the juxtaposed handles 457,458 and the central transverse fold 455 of the base panel 411, as depicted by arrows 461 and 462 in Figure 67.

Figures 67 through 82 depict end panel formation during carton erection, for one end only.

The opposite end of the carton is erected simultaneously, applying the same principles.

Although opposing end panel configurations are disposed asymmetrically (in relation to the longitudinal carton blank axis), as depicted Figures 68 through 88, in practice they could be symmetrical, provided that the opposed erection forces between handle and base preserve a'square'3-D form (ie with no tendency to twist or lozenge).

Upon application of pressure, the base panel 411 begins to splay outward into a flatter form.

Longitudinal edge panels 425,426, joined about elements 434,445 (not visible), remain contiguous-and begin to upstand from side wall panels 453,454.

In more detail, as depicted in Figures 68 through 82, upon application of pressure to the central transverse fold 455, inboard transverse folds 427,428 and diagonal folds 417,418 form, as the base panel 411 splays outward (as depicted in Figure 80).

The positioning of diagonal folds 417,418, inboard (nearer transverse central fold

455) of transverse folds 427,428, causes the longitudinal edge panels 426,425 to be pulled away from side wall panels 453,454 and to begin to upstand-eventually serving as end walls in the erected 3-D carton form.

Figures 68,70 and 73 through 77 illustrate in detail, for one side of an end wall, formed from longitudinal edge panel 425, the transition from flat pack, pre-dispensing form, as in Figure 73, to erect carton, as in Figure 77.

More specifically, application of pressure 435 to the central transverse fold 455, results in the folding of transverse fold 428 and diagonal fold 417.

The offset location of fold 417, relative to fold 428 draws the longitudinal edge panel 425 away from the side wall panel 454, encouraging fold 422 to form-as depicted in Figure 74.

As base panel 411 reaches a generally flat position as in Figures 71 and 75, longitudinal edge panel 425 moves further forward (is more upstanding), and the small triangular panel 437, formed between folds 422 and 417, begins to fold behind the upstanding base end panel 429.

Figure 76 depicts a further stage in carton erection, due to the continued application of downward force 436 to lid panel 483 via handle portion 458.

Diagonal fold 485, on lid panel 483, allows the lid panel to adopt a generally flat position, this action effects outward movement of side wall panel 454, allowing the end longitudinal edge panel 425 to upstand further from side wall panel 454.

When the base panel 411, and lid panel 483 are generally parallel, as shown in Figure 77, the longitudinal edge panel 425 adopts an upstanding position, at right angles to the side wall panel 454.

Figures 69 and 71 depict simultaneous erection of the adjoining end wall panel 426, by viewing the end wall from the other side.

Mirroring the action on longitudinal edge panel 425, discussed above, the application of pressure to the central transverse fold 455, causes inboard transverse folds 427 and diagonal folds 418 to form, and the base panel 411 to splay outward.

The offset location of fold 418, relative to fold 427 draws the longitudinal edge panel 426 away from the side wall panel 453.

The short residual stub fold 419 encourages side wall panel 426 to bow about the projected line of the fold, under the compression caused by the interaction of inboard transverse fold 427 and diagonal fold 418, and thereby upstand somewhat from the side panel 453, as depicted in Figure 69.

If the stub fold 419 were replaced by a full length, diagonal fold, the fold would immediately form and the carton would not erect by'snap-action'-requiring further manual intervention to complete carton erection.

The jointing 432 of panels 425,426 assists to discipline the carton behaviour, locating the panels in a fixed relative position.

Once sufficient pressure has been applied, such that the base panel is generally flat, as depicted in Figure 71, fold 413 forms in end base panel 429 allowing it to upstand from base panel 411.

Base panel 429 upstands from base panel 411, in reaction to pressure exerted across panel 429 by longitudinal edge panels 425 and 426.

The compression causing the longitudinal edge panel 426 to bow is then released or dissipated, allowing panel 426 to'spring'forward, and upstand somewhat from side wall panel 453.

The final stage, to complete the end wall structure of the erect carton 468, as depicted in Figure 72, is facilitated by applying downward pressure to the lid panel structure.

More specifically, downward pressure of the handle portions 457,458, pushes lid panels 482,483 down, diagonal folds 484,485 enable lid panels 482,483 to form a generally flat structure, parallel to the base panel 411.

As the lid panels 482,483 move downwards, side wall panels 453,454 are pushed outward/sideways, allowing the longitudinal edge panels 425,426 to upstand fully from, at right angles to, the side wall panels 453,454, to form the fully erected carton as depicted in Figure 72.

The erect carton exhibits a certain taper inward from base to handle, but the carton sides could be parallel.

Figures 78 through 82 depict in further detail the mechanism of end wall panel erection from flat-pack pre-dispensing configuration Figure 78, through to erect carton Figure 82.

These are fragmentary, part-sectional, plan views of one end wall-as erection of the carton progresses, from flat pack in Figure 78, to an almost flat base panel 411 in Figure 80, with bowing of panel 426, more readily appreciated.

Once the compression of panel 426, is released, or dissipated, as in Figure 81, by the gradual upstanding of base end panel 429, the curvature or bow of panel 426 is reduced, until it is finally upstanding (some 90 degrees) from the side wall panel 453, Figure 82.

The careful disposition of folds described previously are contrived to allow'snap- action'erection of the carton, assisted by the bonding of longitudinal edge panels ensuring that the end panels are correctly aligned upon erection, thus requiring no further manual action beyond the application of pressure.

The carton can now be opened, as depicted in Figure 83 and contents placed inside- it is intended that, once the lid has been re-closed, the carton 468 can be carried, using the handle portions 457,458, in much the same way as a carrier bag.

The handle flap 471, appended to handle portion 458, may be located through the hole in handle portion 457, to (temporarily) hold the handle portions'captive' together, preventing inadvertent opening of the carton.

The carton can then be opened out, to form a tray configuration with upstanding, contiguous, peripheral rim as depicted in Figure 88.

To open the carton, handle portions 457,458 are pulled apart, severing locally bonded end wall panels along perforations 473 (depicted in Figure 86) to form a generally horizontal tray, with upstanding peripheral rim 476 (depicted in Figure 87).

Finally, handle portions 457,458, are in-turned and captured in (arcuate) slots 478, 479 in lid panels 482,483 to create a contiguous, upstanding, peripheral rim around the base 411 and side wall 453,454 panels, as depicted in Figure 88.

As an alternative to bonding, end panels may be interlocked by tabs and slits, preferably while the carton is in the pre-dispensing configuration.

Figures 89 through 102 depict an alternative variant to Figures 62 through 88, deploying variant folds for carton erection.

The alternative crease or fold configuration is depicted in Figure 89, more specifically, the carton blank 510 includes: diagonal tapered double folds 512,513 on opposed sides of the carton base panel 511, tapering to meet offset, inboard transverse folds 527,528 respectively; transverse, tapered, double folds 516,517 meeting diagonal double folds 512,513 at the outboard end of transverse folds 527,528, and extending outboard; - in co-operation with folds discussed in respect of Figures 62 through 88, these folds allow'snap-action'deployment of end wall panels upon carton erection, from pre-

folded dispensing configuration.

+++ Overall, any of the carton configurations illustrated admits of considerable variation- eg in overall proportions, shape and size, along with (sheet) material ingredient and surface finish, whether in pattern or ornamentation.

Similarly, carton panels may incorporate selective cut-outs or apertures, if it is desired selectively to expose or view the carton contents-or, say, to allow venting escape of moisture or steam from hot food contents, thus avoiding degradative internal moisture build up or condensation.

Component List 20 carton blank 22 longitudinal edge panel 23 longitudinal edge panel 24 intermediate, mid-panel 27 handle 28 handle 32 longitudinal edge fold 33 longitudinal edge fold 34 transverse centre fold 35 offset, inboard transverse fold 36 offset, inboard transverse fold 37 outboard (top edge) transverse fold 38 outboard (top edge) transverse fold 41 base/bottom panel 42 base/bottom panel 43 side wall panel 44 side wall panel 45 top panel 46 top panel 51 outboard (diagonal) corner fold 53 outboard (diagonal) corner fold 55 outboard (diagonal) corner fold 57 outboard (diagonal) corner fold 61 inboard (diagonal) corner fold 62 inboard (diagonal) corner fold 63 inboard (diagonal) corner fold 64 inboard (diagonal) corner fold 71 outboard triangular corner piece 73 outboard triangular corner piece 75 outboard triangular corner piece 77 outboard triangular corner piece 81 transverse handle fold 82 transverse handle fold 98 curved edge tuck slit

99 curved edge tuck slit 100 displacement force 131 round nose tab 132 curved slit 133 round nose tab 134 curved slit 135 elongate tab 137 elongate tab 161 outboard corner segment 162 outboard corner segment 261 inboard corner segment 262 inboard corner segment 330 carton blank 337 nose tab 339 double taper wedge fold 341 slot 343'doubled-up'material layer 345'doubled-up'material layer 348 transverse tapered double fold 349 transverse tapered double fold 410 carton blank 411 base panel 412 diagonal fold 413 diagonal fold 414 short diagonal stub fold 415 diagonal fold 416 diagonal fold 417 diagonal fold 418 diagonal fold 419 short diagonal stub fold 421 single fold 422 single fold 423 longitudinal edge panels/end wall panels 424 longitudinal edge panels/end wall panels 425 longitudinal edge panels/end wall panels 426 longitudinal edge panels/end wall panels 427 offset, inboard transverse fold 428 offset, inboard transverse fold 429 base end panel 430 base end panel 432 end panel jointing 433 perforated element 434 perforated element 435 force 436 force 437 triangular panel 445 bonding element 446 bonding element 447 panel bowing 453 side wall panel 454 side wall panel 455 central transverse fold 457 handle ends/portions 458 handle ends/portions 461 force 462 force 468 erect carton 471 handle flap 473 perforations 475 tray configuration 476 upstanding peripheral rim 478 slot 479 slot

482 lid panel 483 lid panel 484 diagonal fold 485 diagonal fold 487 direction of pull 488 direction of pull 510 carton blank 511 base end 512 double tapered fold 513 double tapered fold 516 transverse tapered double fold 517 transverse tapered double fold 527 offset inboard transverse fold 528 offset inboard transverse fold