Title:
Collapsible carton
Kind Code:
A1


Abstract:
A collapsible carton, which may be flat-packed for storage but easily erected to form a many-sided box, and a blank (1) for forming such are disclosed. The carton comprises a base (2) having a plurality of base edges (13a, b, c), and a continuous sidewall (3) defining a base aperture for accepting the base (2), when the carton is erected. In a first aspect, the base (2) comprises two hingedly-joined base portions (11, 12), hingedly joined to the sidewall (3). The carton is characterised in that the base (2) is larger than the base aperture. In a second aspect, the sidewall (3) comprises a plurality of sidewall notches (26a, b, 36a, b). The carton further comprises an integral lid (4) having two lid portions (40, 50) hingedly joined to the sidewall (3). Both lid portions (40, 50) comprise two or more hingedly-joined wings (42a, b, 52a, b). Each wing (42a, b, 52a, b) comprises a wing notch (43a, b, 53a, b) adapted to cooperate with a corresponding one of the sidewall notches (26a, b, 36a, b) such that the lid portions (40, 50) may be secured in a closed configuration when the carton is erected.



Inventors:
Doyle, Patrick Joseph (Sonning, GB)
Application Number:
10/499571
Publication Date:
05/19/2005
Filing Date:
08/06/2003
Assignee:
UNIBOX INTERNATIONAL LTD. (Berkshire, GB)
Primary Class:
Other Classes:
229/143, 229/108
International Classes:
B65D5/18; B65D5/36; B65D5/66; (IPC1-7): B65D5/36
View Patent Images:
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Primary Examiner:
DEMEREE, CHRISTOPHER R
Attorney, Agent or Firm:
WESTMAN CHAMPLIN & KOEHLER, P.A. (MINNEAPOLIS, MN, US)
Claims:
1. A collapsible carton, comprising: a base having a plurality of base edges and comprising first and second hingedly joined base portions; and a continuous sidewall hingedly joined to both of said first and second base portions and defining a base aperture, when said carton is fully erected, for accepting said base; characterised in that said base is larger than said base aperture.

2. The collapsible carton of claim 1, wherein one or more of said base edges is convex.

3. The collapsible carton of claim 1, wherein said sidewall comprises a plurality of sidewall panels, being hingedly joined together and corresponding in number to said plurality of base edges.

4. The collapsible carton of claim 3, wherein said sidewall comprises first and second sidewall portions, a first panel of said first sidewall portion being hingedly joined to a first base edge and a first panel of said second sidewall portion being hingedly joined to a second base edge.

5. The collapsible carton of claim 1, wherein said plurality of base edges is an even number between 6 and 12.

6. The collapsible carton of claim 1, wherein said first and second base portions are formed from a single panel hinged by means of two closely-spaced longitudinal base folds.

7. The collapsible carton of claim 4, wherein said base further comprises two transverse base folds extending from the ends of said first base edge to the ends of said second base edge.

8. The collapsible carton of claim 3, wherein said sidewall further comprises a plurality of stays provided at hinged junctions between selected ones of said sidewall panels, each stay being configurable to support a corner of said base when said carton is erected.

9. The collapsible carton of claim 8, wherein each stay comprises a slit, extending perpendicularly to and across ones of said hinged junctions, and two folds, extending parallel to said junction from each end of said slit to an adjacent sidewall edge.

10. A blank for forming the collapsible carton of claim 1, comprising: a base, having a plurality of base edges and comprising first and second hingedly joined base portions; and a sidewall, being hingedly joined to said base, and having first and second sidewall portions, and at least one flap being hingedly joined to a first end of said sidewall, such that said flap may be fixed to a second end of said sidewall to form a continuous sidewall.

11. The blank of claim 10, wherein said first and second sidewall portions are discrete, being hingedly joined to said first and second base portions respectively, such that respective first ends and second ends of said sidewall portions may be fixed to each other by one of said flaps to form a continuous sidewall, each flap being hingedly joined to either of said sidewall portions at said respective ends.

12. A collapsible carton, comprising: a base having a plurality of base edges; a continuous sidewall defining a base aperture, when said carton is erected, for accepting said base and comprising a plurality of sidewall notches; and an integral lid having first and second lid portions hingedly joined to said sidewall, each lid portion being provided with two or more hingedly joined wings, each of said wings being provided with a wing notch adapted to cooperate with a corresponding one of said sidewall notches, such that said lid portions may be secured in a closed configuration by mutual engagement of cooperating ones of said wing notches and said sidewall notches when said carton is erected.

13. The collapsible carton of claim 12, wherein said lid portions partially overlap when secured in said closed configuration.

14. The collapsible carton of claim 12, wherein said sidewall comprises a plurality of hingedly joined sidewall panels corresponding in number to said plurality of base edges.

15. The collapsible carton of claim 14, wherein said sidewall comprises first and second sidewall portions, a first panel of said first sidewall portion being hingedly joined to said first lid portion and a first panel of said second sidewall portion being hingedly joined to said second lid portion.

16. The collapsible carton of claim 15, further comprising tabs hingedly joined to second and third sidewall panels adjacent said first sidewall panels, said tabs being adapted to support said lid portions when said lid portions are secured in said closed configuration.

17. The collapsible carton of claim 12, the first lid portion further comprising first and second perforations and the second lid portion further comprising an elongate opening, arranged such that when said lid portions are secured in said closed configuration said elongate opening overlies said perforations, such that said perforations are located at each end of said opening.

18. The collapsible carton of claim 17, further comprising a flexible handle member secured at an interior face of said first lid portion, and passable through said elongate opening for use in carrying said carton.

19. The collapsible carton of claim 17, wherein a corrugation direction of said carton is parallel to said elongate opening.

20. A blank for forming the collapsible carton of claim 12, comprising: a base, having a plurality of base edges; a sidewall, being hingedly joined to said base, and having first and second sidewall portions, and at least one flap being hingedly joined to a first end of said sidewall, such that said flap may be fixed to a second end of said sidewall to form a continuous sidewall; and an integral lid, having first and second lid portions being hingedly joined to said first and second sidewall portions respectively, each lid portion having a plurality of wings being hingedly joined to each side of said lid portions; wherein each of said wings is provided with a notch and said sidewall is provided with cooperating notches.

21. The blank of claim 20, wherein said first and second sidewall portions are discrete, being hingedly joined to said first and second base portions respectively, such that respective first ends and second ends of said sidewall portions may be fixed to each other by one of said flaps to form a continuous sidewall, each flap being hingedly joined to either of said sidewall portions at said respective ends.

22. A collapsible carton, comprising: a base having a plurality of base edges and comprising first and second hingedly joined base portions; a continuous sidewall hingedly joined to both of said first and second base portions and defining a base aperture, when said carton is fully erected, for accepting said base and comprising a plurality of sidewall notches; and an integral lid having first and second lid portions hingedly joined to said sidewall, each lid portion being provided with two or more hingedly joined wings, each of said wings being provided with a wing notch adapted to cooperate with a corresponding one of said sidewall notches, such that said lid portions may be secured in a closed configuration by mutual engagement of cooperating ones of said wing notches and said sidewall notches when said carton is erected; wherein when said base is larger than said base aperture.

23. A blank suitable for forming the carton of claim 22.

Description:

The present invention relates to collapsible cartons, such as collapsible hat boxes, gift boxes, and the like, which may be flat-packed for storage when not in use, but which may be easily erected to form a many-sided box.

Boxes for transporting and protecting hats and similar articles are well known. Given the general shape of most hats and the fact that they are often bulky, but fragile, it is desirable for a hat box to be close to cylindrical in shape and to be constructed from a material which is lightweight, but provides sufficient rigidity.

A known hat box design provides a container having a circular base and a rounded sidewall, with a separate circular lid. Such a container is not collapsible and the lid is fastened to the sidewall either with sticking tape, or by tying ribbon around the periphery of the box. Such boxes require substantial storage space on a shop floor, or in a store room before use. In addition, each time the lid is removed from the container, either the sticking tape must be renewed to guarantee the integrity of the box, or the ribbon must be re-tied, both requiring time and effort.

In order to reduce the amount of storage space required for hat boxes prior to use on a shop floor, several approaches have been taken.

A first approach provides a hat box having a separate container and lid, both of which can be stored in substantially flat forms before use. The container is made up of six sidewall panels, each panel having a base flap joined to it at one end, such that the base flaps may be interlocked to produce the base for the box. The lid consists of a hexagonal panel, each side of which has a number of tabs which may be folded over each other and held in place by means of interlocking and abutment arrangements.

While such a box can reduce the amount of storage space needed on the shop floor, the relative complexity of assembly of the box and the time required for this are disadvantageous. In addition, the same method of fastening the lid as discussed above must be used, since this problem is not addressed by this type of box.

A second approach is provided by the hat box disclosed in UK Design No. 1012037, which provides an all-in-one container and lid which may also be stored in a substantially flat form prior to use. As with the first approach, the container has six sides having flaps which interlock to form the base. In addition, there are provided further flaps, joined to each sidewall panel at the other end, which also interlock, to produce a lid and a carrying handle.

While this box may reduce the amount of storage space required on the shop floor before use and provide a reusable lid-fastening mechanism, it is complex to assemble compared with other prior art boxes. In addition, disassembly of the box—an important concern, since customers also need to be able to open and close the lid—is relatively complex.

A third approach is provided by the hat box disclosed in GB-A-2,257,958. The box consists of a collapsible container and a separate lid, both of which may be stored in substantially flat forms when not in use. The lid is constructed essentially in the same manner as that in the first approach above. The container comprises a hexagonal base, formed by two base halves, which are joined by a diametral fold line. The central panel of a set of three sidewall panels is attached by a fold line to a first base side and a further set of panels is similarly attached to a second base side, parallel to the first base side. Attached at each end of the sidewall panels are ‘L’-shaped flaps, respective pairs of which are fixed together. When the carton is erected, these flaps orient radially inwards from the sidewall allowing the base to rest on the extending portions of the flaps so that further downward movement of the base is prevented. Locking strips in the central panels are also provided, to engage and retain the separate lid.

There are a number of disadvantages associated with this box. The radial intrusion of the flaps into the container and the need for the base to rest upon the extending portions result in both the waste of container volume available for use and the requirement of extra material to form a container of a given size. In addition, the separate lid requires either valuable time and effort to assemble at the point of sale (or, indeed, even beforehand), or much-needed storage space on a shop floor, or in a store room, if pre-assembled. Furthermore, the manufacture of such boxes is relatively complex, since two different cutting tools—one for the container and one for the lid—must be set, and it must be ensured that each container has a lid associated with it.

In a known variation of the above arrangement, the ‘L’-shaped supports are replaced by interlocking flaps extending upwardly from either side of the central fold of the base. As the base is pressed down into the aperture defined by the sidewall, the distal ends of the flaps interlock preventing the base from flattening fully. Further pressure on the base causes a snap transformation from a convex to a concave conformation, thus securing the box in the erected state. Neither this arrangement, nor the arrangement using ‘L’-shaped supports, may be easily extended to boxes having more than six sides.

It is therefore desirable to provide a hat box, or other carton, which requires little storage space when not in use. It is also desirable to provide a carton which may be quickly and simply assembled. In addition, it is desirable to provide a carton which maximises the use of the container volume available and which minimises the amount of material required to form the carton. It is further desirable to provide a carton which is relatively simple to manufacture.

The present invention aims to address and fulfil each of the above objectives by providing an improved collapsible carton.

According to a first aspect of the present invention, there is provided a collapsible carton, comprising a base having a plurality of base edges and comprising first and second hingedly joined base portions and a continuous sidewall hingedly joined to both of the first and second base portions and defining a base aperture, when the carton is fully erected, for accepting the base, characterised in that the plane of the base is larger than the base aperture.

By providing a foldable planar base, the plane of which is too large to flatten within the normal erected configuration of the base aperture, pressure of the unhinged base edges on the sidewall provides a supporting mechanism for the base.

It is not necessary for the whole of the unhinged circumference of the base to extend beyond the shape and size which would fit, if flattened, within the base aperture. Particular portions of the unhinged circumference may be selected to so extend, in order to provide support to the edges of the plane of the base at selected points.

Preferably, one or more of the unhinged edges of the base is slightly convex. Preferably, also, the base is adapted to undergo a conformational change when pressed into the base aperture, snapping from an upwardly apexed or convex conformation to a downwardly apexed or concave conformation. The extra extent of the base aperture required for the base to pass between the two conformations is preferably afforded at least in part by the above-mentioned feature of some or all of the unhinged base edges,being slightly convex. An outward bowing of the sidewall panels under pressure from the convex edges then provides the pressure to snap the base into the downwardly apexed conformation.

Alternatively, the required extra extent may be afforded by the sidewall being elastically stretched by the pressure of the base edges on the sidewall. Resistive compression of the sidewall on the base then provides the mechanism to snap the base into the concave state. Alternatively again, the sidewall may retain its erected shape during this action and it may instead be the base which yields, by means of elastic deformation of the hinged junction between the two base portions. Preferably, the hinge is provided by two longitudinal base folds which extend along the length of the junction and yielding results in the folds being pushed more closely together, possibly so that the folds overlie one another.

Associated parts of the collapsible carton are hingedly joined together, thereby facilitating a straightforward folding and unfolding action. Each hinged junction may be provided by a fold in the component material, or by a number of perforations, or slits, in the material. Alternatively, the connection may be provided by suitable flexible joining means connecting two adjacent panels, such as cloth or plastic tape.

The base preferably consists of one piece of material folded at its centre and preferably comprises further folds to assist in providing the conformational change discussed above.

The sidewall of the collapsible carton, formed from the assembled blank, is continuous and defines within itself a cavity, when the carton is erected, into which an article may be placed. The cavity varies in size as the carton is made to collapse. The cross-sectional area of the cavity is at a minimum when the carton is folded down for storage and at a maximum when the carton is erected ready for use, since opposing sidewall panels are then maximally separated from each other.

As the base is pressed downwards, to erect the carton, the base edges in turn force the sidewall portions further apart until the sidewall is fully opened. At this stage, the base is not itself fully open and flat—opposing base edges not being as far apart from each other as possible—and the base must be forced against the resistance of the opened sidewall to achieve this. However, such forcing in fact results in a snapping action, in which the base quickly passes through a planar, or quasi-planar, state to assume a static concave arrangement—a reflection of the static convex arrangement of the base at the point when the sidewall is initially fully open—under compression from the sidewall. The carton is then able to maintain its erect state, until the base is forced upwards, reversing the above procedure.

The invention also provides a collapsible carton, substantially as described above, in which the sidewall further comprises a plurality of stays provided at hinged junctions between selected ones of panels of the sidewall, each stay being configurable to support a corner of the base when the carton is erected. These stays may be used in conjunction with the above base arrangement, as well as other base arrangements which may or may not rely on the base being larger than the base aperture. In the latter case, the base is secured and prevented from further movement by alternate means, such as double stays—one adapted to support a base corner from underneath and the other adapted to secure the corner in place from above—configurable to hold a base corner in place between them.

According to a second aspect of the present invention, there is provided a collapsible carton, comprising a base having a plurality of base edges, a continuous sidewall defining a base aperture, when the carton is erected, for accepting the base and comprising a plurality of sidewall notches, and an integral lid having first and second lid portions hingedly joined to the sidewall, each lid portion being provided with two or more hingedly joined wings, each of the wings being provided with a wing notch adapted to cooperate with a corresponding one of the sidewall notches, such that the lid portions may be secured in a closed configuration by mutual engagement of cooperating ones of the wing notches and the sidewall notches when the carton is erected.

The lid comprises two discrete lid portions, each being hingedly joined to a different part of the sidewall. Preferably, the respective locations at which the lid portions are joined to the sidewall are at opposing sides of the carton.

The wings are disposed on the lid portions at locations and orientations such that, when a lid portion is folded down towards a closed configuration, the junctions between the lid portion and each wing align along edges of the sidewall and the wings themselves may be folded down to overlie outside parts of the sidewall.

When the lid of an erect carton is closed and the lid portions are secured to the sidewall by mutual engagement of respective notches, the stability and rigidity of the box is increased.

According to a third aspect of the present invention, there is provided a collapsible carton, comprising a base having a plurality of base edges and comprising first and second hingedly joined base portions, a continuous sidewall hingedly joined to both of the first and second base portions and defining a base aperture, when the carton is fully erected, for accepting the base and comprising a plurality of sidewall notches, and an integral lid having first and second lid portions hingedly joined to the sidewall, each lid portion being provided with two or more hingedly joined wings, each of the wings being provided with a wing notch adapted to cooperate with a corresponding one of the sidewall notches, such that the lid portions may be secured in a closed configuration by mutual engagement of cooperating ones of the wing notches and the sidewall notches when the carton is erected, wherein when the base is larger than the base aperture so as to undergo a snap transformation from a convex to a concave state when pressed into the base aperture.

Each of the first and second aspects of the present invention solves the problems associated with the prior art boxes, as discussed above. The hat box of the third aspect of the present invention advantageously combines the features of the first two aspects, to provide a hat box, much improved with respect to the prior art, which is both unitary and collapsible.

This invention also provides a blank, or blanks, which are suitable for assembly into the collapsible cartons described above. Assembly may comprise, in particular, gluing, or otherwise joining, corresponding ends of each of two sidewall portions to form the continuous sidewall

The collapsible carton of the present invention advantageously reduces the amount of constituent material required to form the carton and maximises the use of the internal volume of the container. In addition, the collapsible carton advantageously reduces the amount of storage space required when the carton is not in use, while still enabling a user to erect the carton quickly and simply. Furthermore, its manufacture is simplified in comparison with prior art boxes, especially since it is possible to prepare a blank using just one cutting tool.

Specific embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

FIG. 1 is a view of a blank for forming a collapsible carton embodying the present invention;

FIG. 2 is a side view of the carton of FIG. 1, erected and with the lid open;

FIG. 3 is a side view of the carton of FIG. 1, erected and with the lid secured in a closed configuration; and

FIG. 4 is a plan view of the carton of FIG. 1, erected and with the lid open.

In this specification, the term ‘proximal’ describes parts on the carton blank which are close to the centre of the base, while the term ‘distal’ describes parts which, in comparison, are further away from the centre of the base. In addition, the term ‘longitudinal’ describes a direction which is from top to bottom (or bottom to top) of FIG. 1, while the term ‘transverse’ describes a direction which is perpendicular to the longitudinal direction (i.e., from left to right, or vice versa, in FIG. 1).

Referring now to FIG. 1, the collapsible carton blank 1 includes a base 2, a sidewall 3 and a lid 4. In FIG. 1, broken lines represent hinged junctions, provided by a fold in the blank material, and solid lines represent cuts, or slits, in the material.

The base 2 comprises a first base portion 11 and a second base portion 12, which are hingedly joined to each other. The sidewall comprises a first sidewall portion 20 and a second, separate, sidewall portion 30. The lid comprises a first lid portion 40 and a second, separate, lid portion 50.

The first base portion 11 is hingedly joined at a distal edge to a central region of the first sidewall portion 20 and the second base portion 12 is hingedly joined at a distal edge to a central region of the second sidewall portion 30. Hingedly joined on the opposite, distal side of the first sidewall portion 20 is the first lid portion 40, and the second lid portion 50 is similarly hingedly joined to a distal side of the second sidewall portion 30.

Referring in more detail to the base 2, the base portions 11, 12 are hingedly joined together by two closely-spaced longitudinal base folds 14, 15. The provision of two base folds 14, 15, instead of one, improves the collapsing action of the base to fold back on itself and reduces wear on the folds, so that the working lifetime of the box may be increased. Of course, for simplicity, just one longitudinal base fold 14 may alternatively be employed.

The base 2 is polygonal and comprises ten base edges 13. It is envisaged that any even, or odd, number of base edges may be used, although, for practical purposes, it is preferable to have an even number, between 6 and 12. It is desirable to provide a carton, whose base is as close to a circle, or ellipse, as possible. Increasing the number of sides in prior art carton designs above six may be problematic. The present invention offers a collapsible box with a base 2 which may easily have eight, ten, twelve, or more sides, to provide a better approximation to a circle.

The base 2 is oriented in such a way that the top and bottom of the base 2 are occupied by base edges 13a, which are substantially parallel, instead of by base edge junctions. The base 2 takes up an area greater than that of a regular decagon, in one of two ways.

Firstly, the base edges 13 may be straight edges of varying length. In this case, the lengths of the base edges 13a at the top and bottom of the base 2 are equal, the lengths of the base edges 13b adjacent the top and bottom base edges 13a are slightly greater and equal, and the lengths of the base edges 13c—respective pairs of which meet each other at the most longitudinally distal base edge junctions of the base 2—are greater still and equal. This results in a base, which has the shape of an oblate decagon.

Secondly, the base 2 may have the form of a regular decagon, but with some of the base edges 13 being rounded and convex. The base edges 13a, which are hingedly joined to the first and second sidewall portions 20, 30, are required to be straight, so that the desired folding action of the base and sidewalls may be achieved. The remaining base edges 13b,c, however, may comprise rounded segments, which may be of the same, or differing, size, so that an essentially oblate decagon is formed.

Of course, a combination of these two options is also possible and envisaged for use in the hat box of the present invention. The first of these options is, however, shown in FIG. 1.

The base folds 14, 15 extend longitudinally between the two junctions between the base edges 13c, so that the base portions 11, 12 may be folded to overlie one another. Extending perpendicularly to the longitudinal base folds 14, 15, from each side of one of base edges 13a to the same respective sides of the other of base edges 13a, are transverse base folds 16, 17. The base folds 14, 15, 16, 17 offer the base greater freedom in terms of the number of different ways the base may be folded, either partially or wholly, and facilitate the desired snap transformation of the base from a convex to a concave configuration, when pressed down as the final stage of carton erection.

Referring now to the sidewall portions 20, 30, the first sidewall portion 20 comprises five sidewall panels 21, 22a,b, 23a,b, hingedly joined together by folds 29b-e, which extend transversely across the sidewall portion 20. Transverse flaps 24a,b, which extend the full length of the sidewall, are hingedly joined to the externally-facing sides of the outermost, fourth and fifth sidewall panels 23a,b, by transverse panel-to-flap folds 29a,f. These flaps 24a,b are used to fix respective ends of the sidewall portions 20, 30 together, to form a closed sidewall.

First and second tabs 25a,b are hingedly joined to the second and third sidewall panels 22a,b respectively, on a distal side of the first sidewall portion 20. The outer ends of these tabs 25a,b join the sidewall panels 22a,b at the locations of the third and fourth panel folds 29b,e respectively. However, the proximal, inner ends of the tabs 25a,b join the sidewall panels 22a,b at locations adjacent the first and second panel folds 29c,d, but not coinciding with them, to permit greater freedom of relative movement of the tabs 25a,b and the first lid portion 40. The tabs 25a,b are provided to assist in supporting the lid portion 40, when secured to the sidewall, as will be described in more detail below.

Disposed in each of the fourth and fifth sidewall panels 23a,b, on a distal side of the first sidewall portion 20, is a sidewall notch 26a,b. These sidewall notches 26a,b are located more closely to the panel-to-flap folds 29a,f than to the third and fourth panel folds 29b,e. The orientation of the notches 26a,b is such that the proximal ends of the two notches are closer together than the distal ends. Instead of being obliquely oriented, the notches 26a,b may alternatively be disposed perpendicularly to the edge of the first sidewall portion 20, in a transverse direction.

At a proximal side of the first sidewall portion 20, disposed across the junctions between the outermost, fourth and fifth, sidewall panels 23a,b and the flaps 24a,b, and across the junction between the second and fourth sidewall panels 22a, 23a and between the third and fifth sidewall panels 22b, 23b, are stays 27a,b, 28a,b, on which the base 2 may rest. Each stay 27a,b, 28a,b is formed from a longitudinal slit, extending symmetrically about its respective sidewall fold 29a,b,e,f, and a fold extending perpendicularly from each side of the slit, to a proximal side of the first sidewall portion 20.

It is not essential that the slits extend symmetrically about their respective sidewall folds 29a,b,e,f: any longitudinal slit, which extends across both sides of its respective sidewall fold 29a,b,e,f, is appropriate.

In addition, the slits are not all required to be at the same level, nor is it necessary to have all four stays 27a,b, 28a,b. It is envisaged that the main stays 28a,b be provided to engage the base edge junctions at either side of the longitudinal base folds 14, 15, since these junctions are furthest away from the base edges 13a, which are hingedly joined to, and therefore supported by, the sidewall portions 20, 30. The auxiliary stays 27a,b may be provided to offer additional support to the base. In this case, it is envisaged that the level of the main stays 28a,b be higher than that of the auxiliary stays 27a,b, in consideration of the concave conformation of the base in the erected carton.

The proximal side of the first sidewall panel 21 of the first sidewall portion 20 is hingedly joined to the upper base edge 13a, by a first base-to-sidewall fold 18. At either end of the base-to-sidewall fold 18, there are small cutouts, to increase the freedom of relative movement of the first base portion 11 and the first sidewall portion 20.

Hingedly joined to the lower base edge 13a, by a second base-to-sidewall fold 19, is a proximal side of a first sidewall panel 31 of the second sidewall portion 30, also incorporating the cutouts described above.

The layout of the second sidewall portion 30 is generally a reflection of that for the first sidewall portion 20. That is, the second sidewall portion 30 also comprises five sidewall panels 31, 32a,b, 33a,b, hingedly joined together by panel folds 39b-e. Hingedly joined tabs 35a,b are also provided on the second and third sidewall panels 32a,b at a distal side of the second sidewall portion 30 and are formed in the same manner as described above with respect to the first sidewall portion 20. Sidewall notches 36a,b are disposed and oriented in the same manner as described above, along with auxiliary stays 37a,b.

There are, however, a number of minor differences:

Firstly, there are no flaps joined to the outermost panels of the second sidewall portion 30, since the flaps 24a,b of the first sidewall portion 20 are provided to be fixed to the fourth and fifth sidewall panels 33a,b of the second sidewall portion 30 and no further flaps are necessary. Of course, one, or both, of the flaps 24a,b could alternatively be joined to the respective side of the second sidewall portion 30. In any case, the overall effect to be achieved is the same: to fix the sidewall portions 20, 30 together to form a closed sidewall 3.

Secondly, since the flaps 24a,b overlie a part of the fourth and fifth sidewall panels 33a,b of the second sidewall portion 30, the effective functioning of the main stays 28a,b would be prevented, since part of the stays 28a,b would be obscured by the proximal outermost corners of the second sidewall portion 30. Therefore, these corners are removed from the sidewall portion 30 and cutouts 38a,b are thereby formed. It will be apparent from the above description that only two main stays 28a,b are provided with the carton of FIG. 1, while there may be up to four auxiliary stays 27a,b, 37a,b.

Thirdly, the first sidewall panel 31 of the second sidewall portion 30 may optionally include first and second panel perforations 47a,b, disposed centrally, but separated longitudinally, in the panel 31. The perforations 47a,b may be used to carry the carton, by passing a toggled, or knotted, cord (not shown) through each of the perforations 47a,b and using the cord as a handle.

Referring now to the lid portions 40, 50, the first lid portion 40 comprises a first lid section 41 and first and second wings 42a,b, hingedly joined to the lid section by first and second lid section-to-wing folds 46a,b respectively. The first lid section 41 is shaped substantially to cover the area defined by the first base portion 11 and to partially cover a region of the second base portion 12 adjacent the first base portion. At the location on the first lid section 41 which would overlie the first and second longitudinal base folds 14, 15, were the lid section and first base portion 11 themselves overlain, are provided first and second lid perforations 44a,b. The perforations 44a,b, are disposed centrally, but separated longitudinally, in the lid section 41 and may also be used for carrying the carton with a toggled cord.

The lid section-to-wing folds 46a,b are oriented obliquely with respect to the transverse direction previously defined, so that, when the first lid portion 40 is closed down over the cavity formed by the sidewall 3 in the erected carton, the folds are coextensive with parts of the first sidewall portion 20. This feature provides the first lid portion 40 with a tight fit with the first sidewall portion 20.

Each wing 42a,b has a rounded edge and is supplied with a wing notch 43a,b, of a length approximately equal to that of the sidewall notches 26a,b, 36a,b. Each wing notch 43a,b is oriented perpendicularly to the direction of its respective lid section-to-wing fold 46a,b, so that a favourable fit between each wing notch and sidewall notch 26a,b may be achieved. In addition, the notch 43a,b broadens towards its external end, at which region both sides of the notch are rounded, to facilitate engagement of the wing notch 43a,b with its respective sidewall notch 26a,b.

The first lid portion 40 is hingedly joined to a distal side of the first panel 21 of the first sidewall portion 20, by a first sidewall-to-lid fold 45.

Hingedly joined to a distal side of the first sidewall panel 31 of the second sidewall portion 30, by a second sidewall-to-lid fold 55, is the second lid portion 50.

The layout of the second lid portion 50 is generally a reflection of that for the first lid portion 40. That is, the second lid portion 50 comprises a second lid section 51 and third and fourth hingedly joined wings 52a,b. The location and orientation of the third and fourth wings 52a,b, wing notches 53a,b, and lid section-to-wing folds 56a,b respectively are as described with respect to those of the first lid portion 40.

One difference, however, is that the second lid section 51 does not comprise lid perforations. Instead, extending fully between the locations where the perforation would otherwise be formed, is an elongate opening 54. The opening is arranged, so that, when the lid portions 40, 50 are closed down over the cavity, the elongate opening 54 overlies the first and second lid perforations 44a,b.

Assembly of the collapsible carton blank 1, to form the collapsible carton of this embodiment of the present invention, will now be discussed. Such assembly results in the provision of a flat-packed collapsible carton, ready for erection and use.

Using the blank 1 of FIG. 1, each flap 24a,b is folded inwards, about its respective panel-to-flap fold 29a,f, so that the flaps overlie part of the adjacent sidewall panels 23a,b. The base 2 is then folded onto itself, by urging the central base folds 14, 15 in an upward direction, so that the base-to-sidewall folds 18, 19 are drawn together and the lower faces of the first and second base portions 11, 12 confront each other. The first base portion 11 is then folded over, about the first base-to-sidewall fold 18, to overlie the first sidewall portion 20. Similarly, the second sidewall portion 30 is folded over, about the second base-to-sidewall fold 19, to overlie the second base portion 12, which at this stage faces upwards. Next, both lid portions 40, 50 are folded over, about respective sidewall-to-lid folds 45, 55, so that their external faces—those which face downwards in the unassembled blank of FIG. 1—confront the external faces of the first and second sidewall portions 20, 30 respectively. Finally, each flap 24a,b, joined to the panels 23a,b of the first sidewall portion 20, is fixed to a respective panel 33a,b of the second sidewall portion 30, by any suitable fixing means. This may include double-sided sticking tape, glue, staples, heat-sealing, or any other suitable fixing medium. This fixing procedure results in the sidewall portions 20, 30 forming a closed and continuous sidewall 3.

The collapsible carton so-formed is flat and may be easily stored.

Erection of the flat-packed carton will now be described, with reference to FIGS. 2, 3 and 4.

Taking the flat-packed carton, as assembled by following the above steps, the base 2 is urged, along its central base folds 14, 15, in a downward direction. This action forces the centre of the base downwards and the first and second base portions 11, 12 to diverge. As the base-to-sidewall folds 18, 19 are urged further apart, the first and second sidewall portion 20, 30 are, in turn, also forced further apart. Since the sidewall portions 20, 30 are fixed together by the flaps 24a,b, the sidewall panels 21-23, 31-33 are not permitted to move apart from each other in a uniform manner. Instead, the sidewall 3 is forced to open out to form a polygonal enclosure, in which the first sidewall panels 21, 31 are separated by a maximal extent and the fourth and fifth sidewall panels 23, 33 are separated the least. As the sidewall 3 expands, and the size of the internal cavity defined by it increases, each of the base edges 13 comes into contact with a corresponding sidewall panel 21-23, 31-33, ensuring a uniform expansion of the sidewall.

Because the base is too large to flatten within the sidewall 3 at the point when the sidewall is fully open, the base adopts a convex conformation. Further downward pressing on the base 2 is opposed by the fully open sidewall 3. When sufficient downward force is applied, however, the base passes quickly through a flat, quasi-planar or other intermediate non-equilibrium conformation, to assume a stable concave conformation, which is largely a reflection of its preceding convex conformation, in a ‘snapping’ action. The carton is then erected and ready for use, as shown in FIGS. 2 and 4.

The stays 27a,b, 28a,b provide support and constraint to further movement of the base 2, in addition to the compressive forces of the sidewall 3 on the base, afforded by the tight fit of the base with the sidewall. Each stay 27, 28, 37 is easily and quickly set in place, by pressing the part of the stay which coincides with the panel folds 29a,b,e,f, 39b,e radially inwards. The stay 27, 28, 37 will then snap into place, forming a concave segment in the proximal side of the sidewall 3, on which the base may rest, so that further downward movement of the base is prevented. When the stays 27, 28, 37 are not required, they may be returned to their original configuration by pressing them radially outwards, at the same part of the stay.

In order to secure the lid in a closed configuration, the first lid portion 40 is closed over its respective part of the cavity defined by the sidewall 3. The wings 42a,b are then folded down, about the lid section-to-wing folds 46a,b respectively, so that they confront the first sidewall portion 20. Each wing notch 43a,b is then, in turn, manipulated to engage the respective first sidewall portion notch 26a,b, thereby securing the first lid portion 40 to the first sidewall portion. During the closure of the first lid portion 40, the tabs 25a,b are pressed downwards and inwards in a cooperating manner. The tabs 25a,b then act to support the first lid portion 40, when it has been secured to the first sidewall portion 20.

Next, the second lid portion 50 is closed over its respective part of the cavity. At this point, the second lid portion 50 partially overlaps the first lid portion 40, which is already secured in place. The wings 52a,b are then folded down, about the lid section-to-wing folds 56a,b respectively, so that they confront the second sidewall portion 30. Each wing notch 53a,b is then, in turn, manipulated to engage its respective second sidewall portion notch 36a,b, thereby securing the second lid portion 50 to the second sidewall portion. During the closure of the second lid portion 50, the tabs 35a,b cooperate with and support the second lid portion 50, in the same manner as described with respect to the first lid portion 40. The lid 4 is then secured in a closed configuration, as shown in FIG. 3.

Once the lid 4 has been secured to the sidewall 3, a toggled, or knotted, cord, passing through each of the lid perforations 44a,b in the first lid portion 40, may be passed through the elongate opening 54 in the second lid portion 50, so that the carton may be carried.

Disassembly of the carton is simple and easy: the wing notches 43, 53 are disengaged from the sidewall notches 26, 36 and the lid portions 40, 50 are folded over, so that they confront the external faces of the sidewall portions 20, 30. Next, the base 2 is forced upwards, along the central base folds 14, 15, so that the base edges 13a, the base portions 11, 12, and the sidewall portions 20, 30 are drawn together, and the carton assumes its original, substantially flat form.

The collapsible carton of the present invention may be manufactured to have any chosen internal volume, by adjusting the sizes of the constituent parts in proportion. It is envisaged that a range of collapsible cartons may thereby be provided, so that articles of varying size may be efficiently contained and transported in an appropriately-sized box. Practically, the manufacture of cartons of different sizes is governed by the size of the cutting machine employed. For some larger carton sizes, it may be necessary to produce the carton in several parts and join them by any suitable hinged joining means.

The collapsible carton of the present invention may be manufactured from any suitable material, such as boards or plastics, but is preferably made of cardboard. One particular grade of cardboard suitable for hat box embodiments of the present invention is 190 gsm e-flute corrugated cardboard.

If the material is cardboard, the corrugations, or flutings, in the cardboard may lie in any chosen direction. However, it is preferable that the corrugation direction lies parallel to the elongate opening 54. The longitudinal rigidity thus provided by the corrugations strengthens the lid 3 and reduces the likelihood of the lid portions 40, 50 buckling under the weight of an article being transported in the carton.

Although the base 2 has been described as being formed of one panel, the base may alternatively comprise two separate pieces of material—each piece constituting one of the base portions 11, 12—which are joined together, again by any of the means described above. On the other hand, the two pieces may not be joined together as described: instead, one piece may partially overlap the other at the centre of the base 2 and the hinging mechanism may be provided by the edge of the smaller base portion, on which the larger base portion rests, acting as a fulcrum. In any case, each base portion 11, 12 is hingedly joined to its respective sidewall portion 20, 30.

The sidewall may consist of one piece of material, which is subdivided, equally, or otherwise, into the two sidewall portions 20, 30. In this case, a blank for forming the carton would be produced with just one part of the sidewall 3, corresponding to the first sidewall portion 20, being hingedly joined to the base 2 (by a fold, for example). On assembly of the blank to form the collapsible carton of the present invention, another part of the sidewall 3, corresponding to the second sidewall portion 30, would need to be joined to the base 2 by a suitable hinging means (other than simply a fold, since the two parts would actually need to be physically connected together).

Alternatively, the sidewall 3 may comprise two discrete sidewall portions 20, 30, each of which is hingedly joined to its respective base portion 11, 12 by, for example, a fold, and which are themselves fixed together, on assembly of a blank 1, in such a way that the junctions between them are hinged.

Finally, instead of being formed from two pieces, the integral lid 4 may be formed of only one piece, which extends to cover the entire cavity defined by the sidewall 3. In this case, it is necessary to provide more than two wings on the one-piece lid to ensure that the lid may be secured in the closed configuration. This requires a more intricate carton design, although the overall functioning of the carton remains as described above.

It will be readily understood that many other embodiments of the present invention exist and that the embodiments described above are by way of example only.