GB2315735A - Carton formed from a blank - Google Patents

Abstract

A pre-fabricated carton structure (40) embodies multi-layer side walls (12,13, 14; 15,16,17) forming a reinforced peripheral rim with inter-nesting locking flaps (15) sandwiched therebetween and upstanding from a base (11). The carton may be formed from more than one blank to provide a multi-layer base.

Description

Folding Carton This invention relates to cartons, and is particularly, but not exclusively, concerned with folding or collapsible cartons.

For such cartons it is generally desirable to combine structural rigidity and robustness, whilst preserving lightness and collapsibility.

The term 'carton' is used herein to embrace any configuration of hollow structure, closed or open, particularly thin-walled, pre-fabricated structures.

The carton art is well-developed and typically cartons are derived from flat sheet material, sub-divided by multiple cuts and folds, co-operatively disposed in an intersecting grid or lattice array, to allow progressive folding and inter-nesting into a three-dimensional erected assembly form.

For economy of manufacture it is desirable to use sheet material of standard production size and to minimise wastage and the number of sheets employed for each carton. This can impose limitations on carton size and configuration.

According to one aspect of the invention, a carton is fabricated from a single sheet material incorporating a plurality of cuts and folds to achieve in an erected condition a peripheral wall upstanding from a base and embodying reinforcement or stiffening by overlapping of layers.

The strength and structural integrity of the carton is imparted by the repeated folding over of the walls to achieve multiple overlapping thickness and collectively a stiff upstanding peripheral rim - yet the floor need be only a single thickness or layer. This in turn admits of construction from a single integral sheet.

Since the walls comprise multiple overlapping layers, the multiplicity and spacing or depth of the intervening folds required will vary.

Thus, one layer may be folded directly over to lie facing an adjoining layer, possibly with a marginal gap left therebetween to accommodate insertion of an additional layer, as a locking tab.

The panel representing a carton base is disposed at the centre of the flat array of wall panels.

The wall panels may be disposed in a linear array, ie in a long strip, so that the panels are 'rolled' over on to one another.

Alternatively, the panels may be arranged for a combination of inward folding of side panels and such linear strip 'rolling'.

The thickness or overlapping depth of the walls can be varied with the panel arrangement. Thus, for stronger walls, more folding panels can be incorporated.

Such cartons may be constructed from a single sheet, or, to free carton size limitations from sheet size limitations, from multiple overlaid sheets to construct larger cartons.

In such multiple sheet arrangements, each sheet could form some or all of a base and wall portions.

Desirably, the carton is fabricated from corrugated plastics sheet, such as 'Correx' or 'Corruboard (Trade Marks).

There now follows a description of some particular embodiments of the invention, by way of example only, with reference to the accompanying diagrammatic and schematic drawings, in which: Figures 1 through 8 show the progressive stages of assembly of a carton from a flat pack integral sheet, and Figure 9 through 17 show the progressive stages of assembly of the alternative embodiment.

Figures 18 through 21 show a variant of Figures 1 through 8, with a shallower reinforcement rim, to allow a larger carton from a given sheet size limitation.

More specifically: Figure 1 shows a carton in its laid out flat, unfolded configuration; Figure 2 shows the flat carton with one of the side walls part folded; Figure 3 shows further folding of the two opposite side walls; Figure 4 shows the two side walls fully folded together with a partly folded end wall; Figure 5 shows the two side walls and one end wall folded, the second end wall still being flat.

Figure 6 shows a flat carton with an additional area added to the side walls; Figure 7 shows a part-assembled carton with flaps adapted to allow a side wall to be collapsed; Figure 8 shows a part-assembled carton with fasteners applied to the multiple layer walls; Figure 9 shows one of the two flat cartons making up the second carton embodiment; Figure 10 shows the second of the flat carton elements; Figure 11 shows the two unfolded elements laid flat on top of one another; Figure 12 shows one of the side walls being folded; Figure 13 shows further folding of the side wall; Figure 14 shows further folding of the two opposite side walls; Figure 15 shows the two side walls and one end wall part-folded, while the second end wall lies flat; Figure 16 shows the two side walls and one end wall fully folded, the second end wall being flat; Figure 17 shows the fully assembled carton; and Figures 18 through 21 show progressive assembly stages for a variant of the carton of Figures 1 through 8.

Referring to the drawings, a carton is fabricated from a flat shape or carton 'blank' 20 - cut out of a sheet of material, such as cardboard or corrugated synthetic plastics, as indicated in Figure 1.

The flat shape is sub-divided into a series of contiguous rectangular panels 11 through 17, with intervening creases 40 at and about which the material will be folded.

Each panel is attached to one or more others along one or more of its four side edges.

A central panel 11 constitutes the floor of the assembled carton 40. This floor panel 11 has a further panels 12, 16 adjoining each of its four sides.

The panels 12, 13 and 14 are folded together to form individual side walls of the assembled carton 40, whilst panels 15, 16 and 17 are interfolded to form end walls.

The side walls are constructed, firstly by folding the panels 14 inwards, to lie on top of the panels 13, as shown in Figure 2. The consequent double thickness layers are then folded over to lie upon panels 12, the flaps 15 remain projecting from either side of the folded wall, as illustrated in Figure 3.

The two folded side walls are stood upright, so that they are generally perpendicular to the floor panel 11. The flaps 15 are then turned inwards to lie square to the side walls and along the side edges of the floor panel 11.

The carton end walls are constructed by folding panels 16 to lie perpendicular to the floor panel 11.

The flaps 15 lie adjacent the inside of the panels 16, and panels 17 are folded over to trap the flaps 15.

The combined surface area of the pairs of opposed panels 14 is approximately equivalent to the areas of the panels 12 or 13.

Similarly, the combined area of the pairs of opposed flaps 15 is generally equivalent to the areas of the panels 16 or 17.

A double fold 23 between panels 14 and 13 provides an intervening 'spine' of depth equivalent to double the material thickness, so that they may lie flat over one another without stretching the spine.

Similarly, a triple depth spine fold 22 is provided between panels 12 and 13 to accommodate the combined depth of two material layers formed by folding panels 13, 14 over on to one another, along with the depth of the panel 12.

Folds 21 between panels 11 and 12 is just sufficient to allow the panels to be folded at right angles to one another.

This also applies to folds 24 between the panels 12 and 15, as the flaps 15 are returned to lie at right angles to the panels 12 in order to fit in between the side panels 16 and 17.

Folds 25 between the base panel 11 and opposite side panels 16 is again just sufficient to allow the panels 11 and 16 lie at right angles to one another.

Folds 26, between panels 16 and 17 is a 'triple fold', to accommodate the intervening flaps 15.

Overall the combined side wall depth of the assembled carton 40 is of triple thickness - for example panels 12,13 and 14 on the one hand and panels 15,16 and 17 on the other hand.

The additional layers lie within the embrace of the outer panels 12 and 16, which are contiguous with the base 11.

The width of the panels 13, 14 is marginally less than that of the panels 11, 12, to create slots 31 between the panels 13, 14 and the panels 15,16, to accommodate the panels 17.

The panel 17 is a tight interference fit between the inside faces of the opposing side wall panels 13 - and so cannot readily be withdrawn or dislodged.

Additional reinforcement or stiffening layers may be added to the walls by incorporating further panels in the carton blank.

Figure 6 shows one such variant, with supplementary panels 18 on the outer margins of the panels 18. The width of the various folds is adapted accordingly to accommodate the cumulative material thickness.

Figure 7 shows a carton variant adapted to enable one of the side walls to be opened.

Flaps 41 are fitted which can simply be slid out from between the multiple layers of the end wall, with minimal resistance. Some profiling, for example curvature of their upper edges may be embodied to facilitate this.

As illustrated in Figure 8, fasteners 51 can be fitted to help prevent the carton wall from unravelling.

The fasteners 51 penetrate the multiple layers to hold them together at strategic locations over the carton profile.

If one of the side walls is adapted, as in Figure 7, to have a releasable side wall, fasteners could be fitted to adjacent end walls, holding the locking flaps in place between the layers.

Figures 9 through 16 depicts another carton variant with multiple inter-fitting sheets 120, 121.

Figure 9 shows a sheet 120 with a base panel 100 with end panels 106, 107.

Another sheet, shown in Figure 10, has a base panel 101 and side panels 102,103 with ear or wing flap panels 105.

In Figures 10 through 16, the flaps 105 are illustrated with a curved profile, but they may also simply be squared.

Figure 11 shows the sheets 120,121 juxta-positioned so that the respective base 100, 101 panels are superimposed, one on top of the other, and respective side panels 103, 103 and 106,107 are orientated to lie mutually at right angles.

Assembled carton end walls are constructed by folding panel 102 so that it is upright to the base 101, 102, whereupon panel 103 is folded over inwardly to lie flat against panel 102, as shown in Figure 14.

Figures 13 and 14 show the flaps 105 are folded at right angles to the panels 102 to lie along the side edges of the base panels 100,101.

Side walls are constructed by folding panels 106 to lie upright to the base panels 100, 101, and adjacent the flaps 105.

Panels 107 are then folded over the panels 106 to sandwich the flaps 105 therebetween.

Fasteners are fitted to hold the multiple layers of the walls in their correct relative dispositions.

Such fasteners may be screw or snap-action bullet inter-fitting male and female elements with load-spreading heads, to obviate pull-through.

Figures 18 through 21 show a variation in depth of peripheral wail reinforcement rim by adapting the outermost panel dimensions and otherwise correspond generally to the embodiment of Figures 1 through 8 and so will not be described in further detail. It should however be appreciated that varying the rim thickness could allow a larger overall structure from a given sheet size.

Whilst the various constructions described admit of considerable variation in configuration, it should be noted that reinforcement and stiffening of a peripheral rim upstanding from a base can achieve a robust structure, even with a single thickness base.

The multiple side wall or rim thickness resists deformation or tearing through casual handling or impact loads and contributes to the load carrying capacity.

Additionally, carry handles or apertures may readily be fitted to or inserted in the reinforced rim, without further elaborate reinforcement.

Moreover, the entire structure can be formed from a single sheet of material, with overall dimensions consistent with the economic constraints of sheet material sourcing and manufacture.

Beyond single sheet dimensional limitations, multiple overlaid sheets may be employed to construct larger cartons.

Whilst open top cartons have been described, iids may be fitted, either as discrete entities or entrained - eg hinged to and even integrally formed with the base.

Thus a removable discrete lid may be constructed in the same manner as the carton itself - that is with a reinforced multiple layer rim, configured to be a marginal clearance fit upon the upstanding open rim of the carton.

A hinged lid could be constructed from a common sheet as the carton itself, by extending the carton blank in one direction and repeating the panel configuration with appropriate dimensional adjustment.

The carton may be reinforced by insertion of localised corner bracing elements, eg of moulded plastics, and which can also support carton stacking.

Similarly, the carton walls and interconnections may be reinforced with stiffening elements, eg rods or wires, around which the panel folds and sandwiched between panels.

Component List 11 floor panel 12 panel forming outer layer of side wall 13 panel forming inner layer of side wall 14 flaps within side wall 15 outward flaps of side wall 16 panel forming outer layer of end wall 17 panel forming inner layer of end wall 18 panel forming additional layer to side wall 21 fold between panels 11 and 12 22 fold between panels 12 and 13 23 fold between panels 13 and 14 24 fold between panels 12 and 15 25 fold between panels 11 and 16 26 fold between panels 16 and 17 31 gap 40 assembled carton 41 shaped flaps on sides of panel 12 51 fastener 100 floor panel 101 floor panel 102 panel forming outer layer of side wall 103 panel forming inner layer of side wall 105 outward flaps of side wall 106 panel forming outer layer of end wall 107 panel forming inner layer of side wall

Claims (10)

1. Claims 1.

   A collapsible carton (40) comprising a pre-fabricated sheet or carton blank (20) sub-divided into an array of panels (11-17) by a plurality of intersecting cuts and folds (22-26) disposed in a co-operative lattice or grid to allow the panels to be selectively brought into an erected or assembled condition in which adjacent side panels (12,13,14; 15,16,17) surmount and surround a base panel (11), the side panels having a multi-layer structure formed by overlapping and folding into face-to-face abutment of edge adjoining panels, with inter-nesting locking flaps (15) sandwiched between said overlapping panels.
2. 2.

   A carton (40) of sheet material cut and folded into a series of inter-connected panels designating a base and peripheral walls, the assembled carton walls comprising multiple overlaid panels, with inter-locking flaps between adjacent walls extending from the side walls to lie between the multiple layers overlaid panels of adjacent walls.
3. 3.

   A carton as claimed in either of the preceding claims, assembled from a single sheet (20), the base (11) being of single thickness and braced by the multiple thickness walls upstanding therefrom as a stiffened peripheral rim.
4. 4.

   A carton as claimed in any of the preceding claims, in which peripheral walls incorporate multiple overlapping panels to a marginal depth sufficient to provide stiffening consistent with achieving a desired carton size from a given sheet size.
5. 5.

   A carton as claimed in any of the preceding claims, assembled from multiple sheets (120, 121), overlaid to form a multi-layer base (105, 106) with interlocking walls selectively combined from each sheet.
6. 6.

   A carton as claimed in any of the preceding claims, including side wall flaps with curved upper edge profiles to facilitate insertion and withdrawal and allowing a hinged opening side wall.
7. 7.

   A carton as claimed in any of the preceding claims wherein fasteners are fitted to penetrate the multiple layers of the carton walls to maintain the integrity thereof and the relative positions of the flaps.
8. 8.

   A carton as claimed in any of the preceding claims with reinforcement internal corner pieces disposed to brace the structure and support carton stacking.
9. 9.

   A collapsible pre-fabricated carton substantially as hereinbefore described with reference to, and as shown in, the accompanying drawings.
10. 10.

    A pre-fabricated carton blank for a carton as claimed in any of the preceding claims.