WO2007051238A1

WO2007051238A1 - Foldable carton

Info

Publication number: WO2007051238A1
Application number: PCT/AU2006/001628
Authority: WO
Inventors: Maxwell Julien; Matthew Colin Bell
Original assignee: Maxwell Julien; Matthew Colin Bell
Priority date: 2005-10-31
Filing date: 2006-10-31
Publication date: 2007-05-10
Also published as: EP2029444A1; US20060032899A1; EP2029444A4

Abstract

A collapsible carton which is formed from a single cardboard blank which when formed from the blank is capable of being folded between a folded flat condition and an erect condition whereby when in the erect condition the carton has a floor (11) and four side panels (12, 13, 14 and 15) to define a generally rectangular prismatic shaped space, wherein the floor panel is formed of a single panel and the junction between the floor and each of the side panels is defined by a closed fold line therebetween, a pair of opposed first side panels (12 and 13) having a pair of diagonal fold lines (21 and 22), extending from the junction between the sides of the floor and the sides of the respective first side panel and converging to terminate at a transverse central axis of the first side panel said diagonals being substantially perpendicular to each other.

Description

FOLDABLE CARTON

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of US Patent Application No. 10/230,385 filed on August 28, 2002 the contents of which is incorporated herein by way of reference. US Application No. 10/230,385 is a continuation-in-part of US Patent Application No. 09/762,095 filed on February 2, 2001, which claims priority from Australian Provisional Application No. PP 5037 filed on August 4, 1998.

BACKGROUND OF THE INVENTION

1. The Field of the Invention This invention relates to collapsible packaging such as cartons and the like which are generally formed from blanks formed from a substantially rigid sheet material whereby the blanks are folded to form a carton.

2. The Relevant Technology The cartons to which the invention relates are used in a wide variety of circumstances and one particular example of the application of the cartons relates to the forms of packaging used with take-away food items. It is a common characteristic of such cartons that they are not capable of accommodating liquid contents without the utilisation of a supplementary containment means. As a result, in the event of any spillage within the carton the liquid contents of the carton will leak and can create an undesirable circumstance for customers.

In the past, attempts have been made to provide cartons which can to some degree overcome this problem. One example of such a carton is disclosed in US patent specification 4471904 which provides a carton whereby the floor is held in a raised position from the lower limit of the carton. However, in order for the carton to be foldable there is no closed junction between the floor panel and the end and side panels. As a result, there is still the likelihood of leakage therebetween. A further example comprises that which is disclosed in US patent specification 2430755. However, the carton disclosed in that specification is not one that which is capable of being folded and providing a closed junction between the floor and the side panels.

It is desirable to provide a carton which when assembled from a blank can be folded to lie in a substantially flat condition and which can be readily unfolded into an erect condition whereby when in the erect condition no further action or containment means need be provided in order to prevent the leakage of the contents of the carton escaping from the base of the carton.

SUMMARY OF THE INVENTION

According to one embodiment the invention comprises a collapsible carton which is formed from a blank having a peripheral boundary edge and being continuous within the peripheral boundary edge, the carton when formed from the blank is capable of being folded between a folded flat condition and an erect condition whereby when in the erect condition the carton comprises: a floor panel; two opposed end panels; and two opposed side panels to define a generally rectangular prismatic shaped space, wherein the end panels and the side panels have substantially the same height, wherein the floor panel has a perimeter formed from a junction between the floor panel and each of the side panels and each of the end panels, the junction being liquid- tight, wherein the end panels each have a pair of first diagonal fold lines extending from the junction between the sides of the floor panel and the sides of the respective end panel and converging to terminate at a transverse central axis of the end panel, the pair of first diagonal fold lines being substantially perpendicular to each other, the end panels have a height being equal to or greater than the termination of the first diagonal fold lines, wherein the floor panel is provided with ' a first central fold line which is substantially centrally located and which extends between the end panels and is adapted to permit the floor panel to fold inwardly into the space about the first central fold line while the first diagonal fold lines fold, wherein the end panels have a second central fold line extending centrally from the floor panel to an opposed edge of the end panels, wherein each end panel and each side panel is formed with an integral extension panel, being of substantially the same height as its respective end panel or side panel, wherein in the erected carton an abutting edge of adjacent extension panels are defined by a closed fold line, wherein the extension panels of each end panel each have a pair of second diagonal fold lines extending between the junction between the end panel and the extension panel at the sides thereof and converging to terminate at the junction of the second diagonal fold lines with an outer edge of the extension panels, whereby on the erection of the carton the extension panels of each end panel fold about the second diagonal fold lines and the junction with the end panels to an intermediate position where the extension panels of the side panels fold over the space to close the space and lie substantially parallel to the floor panel, wherein the extension panels of the end panels are foldable about their junction with their respective end panels to lie substantially parallel to and adjacent their respective end panels on an outside of the space in a self locked position, and wherein the floor panel, side panels and end panels are relatively configured whereby when the carton is supported on a planar support surface the floor panel is in face to face contact with the planar surface.

In another embodiment the invention may comprise a collapsible carton which is formed from a blank having a peripheral boundary edge and being continuous within the peripheral boundary edge, the carton when formed from the blank is capable of being folded between a folded flat condition and an erect condition whereby when in the erect condition the carton comprises: a floor panel; two opposed end panels; and two opposed side panels to define a generally rectangular prismatic shaped space, wherein the end panels and the side panels have substantially the same height, wherein the floor panel has a perimeter formed from a junction between the single floor panel and each of the side panels and each of the end panels, the junction being liquid-tight, wherein the end panels each have a pair of first diagonal fold lines extending from the junction between the sides of the floor panel and the sides of the respective end panel and converging to terminate at a transverse central axis of the end panel, the pair of first diagonal fold lines being substantially perpendicular to each other, the end panels have a height being equal to or greater than the termination of the first diagonal fold lines, wherein the floor panel is provided with a first central fold line which is substantially centrally located and which extends between the end panels and is adapted to permit the floor panel to fold inwardly into the space about the first central fold line while the first diagonal fold lines fold, wherein the end panels have a second central fold line extending centrally from the floor panel to an opposed edge of the end panels, wherein each end panel and each side panel is formed with an integral extension panel, being of substantially the same height as its respective end panel or side panel, wherein in the erected carton an abutting edge of adjacent extension panels are defined by a closed fold line, wherein the extension panels of each end panel each have a pair of second diagonal fold lines extending between the junction between the end panel and the extension panel at the sides thereof and converging to terminate at the junction of the second diagonal fold lines with the outer edge of the extension panels, whereby on the erection of the carton the extension panels of each end panel fold about the second diagonal fold lines and the junction with the end panels to an intermediate position where the extension panels of the side panels fold over the space to close the space and lie substantially parallel to the floor panel, wherein the extension panels of the end panels are foldable about their junction with their respective end panels to substantially parallel to and adjacent their respective end panels on an outside of the space in a self locked position, wherein the floor panel, side panels and end panels are relatively configured whereby when the carton is supported on a planar support surface the floor panel is in face to face contact with the planar surface, and wherein, the blank comprises a plurality of glue flaps where respective glue flaps are glued to an inside surface of the side panels and overlay substantially the whole length of the side panels.

Another embodiment of the invention may be in the form of a collapsible carton comprising: a floor panel, two opposite first side panels, and two opposite second side panels, the panels together defining a generally rectangular prismatic shaped space, wherein the first side panels and the second side panels have substantially the same height, wherein the floor panel has a perimeter formed from a junction between the floor panel and each of the first and second side panels, the junction being liquid tight, wherein each of the first side panels and each of the second side panels is formed with an integral extension panel, the extension panels being of substantially the same height as its respective side panels, wherein in the erected carton an abutting edge of adjacent extension panels is defined by a closed fold line, the extension panels together forming a self locking closure being foldable to fully closed position where the extension panels of the second side panels fold over the space to close the space and lie substantially parallel to the floor panel, and the extension panels of the first side panels are foldable to lie substantially parallel to the and adjacent their respective first side panels on an outside of the space in a self locked position where a biasing force is applied to the extension panels of the first side panels in a direction of their respective first side panels, and a plurality of glue flaps extending from the first side panels, the glue flaps being glued to an inside surface of the second side panels and overlying substantially the whole length of the second side panels.

BRIEF DESCRIPTION OF THE DRAWINGS

The description is made with reference to the accompanying drawings of which; Figure 1 is a plan view of a blank according to the first embodiment;

Figure 2 is an isometric view of a partially folded blank according to the first embodiment;

Figure 3 is an isometric view of an erected carton formed from the blank of the first embodiment with the extension panels open; Figure 4 is an isometric view of an erected carton formed from the blank of the first embodiment with the extension panels partially closed;

Figure 5 is an isometric view of an erected carton formed from the blank of the first embodiment with the extension panels fully closed;

Figure 6 is an isometric view of a folded carton formed of a blank according to the first embodiment;

Figure 7 is a plan view of a blank according to the second embodiment;

Figure 8 is an isometric view of an erected carton formed from a blank of the second embodiment with the extension panels open;

Figure 9 is an isometric view of an erected carton formed from the blank of the second embodiment with the extension panels partially closed;

Figure 10 is an isometric view of an erected carton formed from the blank of the second embodiment with the extension panels fully closed;

Figure 11 is an isometric view of a folded carton formed from a blank of the second embodiment; Figure 12 is a plan view of a blank according to the third embodiment;

Figure 13 is an isometric view of an erected carton formed using the blank of the third embodiment with the extension panels open;

Figure 14 is an isometric view of an erected carton formed from the blank of the third embodiment with the extension panels partially closed; Figure 15 is an isometric view of an erected carton formed from the blank of the third embodiment with the extension panels fully closed;

Figure 16 is an isometric view of a folded carton formed from the blank of the third embodiment; Figure 17 is a plan view of a blank according to the fourth embodiment; Figure 18 is an isometric view of an erected carton formed from a blank according to the fourth embodiment with the extension panels open;

Figure 19 is an isometric view of an erected carton formed from the blank of the fourth embodiment with the extension panels partially closed;

Figure 20 is an isometric view of an erected carton formed from the blank of the fourth embodiment with the extension panels fully closed;

Figure 21 is an isometric view of a folded carton formed from a blank according to the fourth embodiment;

Figure 22 is a plan view of a blank according to the fifth embodiment;

Figure 23 is an isometric view of an erected carton formed from a blank according to the fifth embodiment with the extension panels open;

Figure 24 is an isometric view of an erected carton formed from the blank of the fifth embodiment with the extension panels partially closed;

Figure 25 is an isometric view of an erected carton formed from the blank of the fifth embodiment with the extension panels fully closed;

Figure 26 is an isometric view of a folded carton formed from a blank according to the fifth embodiment; Figure 27 is a plan view of a blank according to the sixth embodiment; and

Figures 28a to 28g illustrate the assembly of a carton according to the sixth embodiment from the blank shown at Figure 27;

Figures 29a to 29c illustrate a blank and two stages of folding the blank to form a seventh embodiment of the invention.

BEST MODES FOR CARRYING OUT THE INVENTION

The following is a description of several embodiments of the invention. The description is not exhaustive of all possible embodiments of the invention but rather is illustrative of different forms of the same invention.

Each of the embodiments is directed to a carton which is formed from a stiff sheet material such as cardboard where the sheet material is formed into a blank. The blank is continuous in that it contains no holes or slots internal of its peripheral edge. The blank can be folded to form a carton whereby when the carton has been formed it can be readily folded into a substantially flat condition and can be subsequently erected from the folded flat condition to provide a carton defining a generally rectangular prismatic shaped space with a flat closure or lid that lies parallel to a floor panel and with junctions between the floor panel and side panels and end panels of the carton being closed or sealed, as are junctions between the end panels and the side panels so that the carton is liquid tight along these junctions and thus resistant to the leakage of the contents. In forming the carton from the blank the formed carton may initially take the form of the folded carton which can then be erected into the carton when it is required. Alternatively in forming the carton from the blank it may initially take the form of the erected carton to be then capable of being folded into a substantially flat condition for transportation and/or storage and subsequent unfolding into an erected carton when required.

In various embodiments of the carton the closure or lid is formed as extension panels to each of the side panels and end panels where the extension panels have substantially the same height and adjacent extension panels are interconnected at the adjacent edges. Further the extension panels are formed integrally with respective side panels and end panels. The extension panels on each of the end panels are capable of folding about the junction with the respective end panel and about diagonal fold lines in the extension panel. This will result in the folded extension panel extending laterally from the respective end panel and as a further result the extension panels on the side panels will have been caused to have hinged about their junction with the respective side panel to overlie the space defined by the carton. It has been found that because of the construction of the carton where end panels, the side panels and the floor panel are all closed or fully joined (i.e. formed without any discontinuities such as holes, slots or openings) that, on hinging the folded extension panel about its junction with the respective end panel to a position (locked position) parallel and alongside the end panel, a biasing force is applied to the folded extension panel causing it to move towards the end panel and thus be retained at that locked position. Without wishing to be bound by theory, this bias force is believed to arise from tension within the panels created due to the junctions of the panels being closed or fully joined. That is, this construction in effect provides a "snap" lock or closing of the closure or lid.

The first embodiment as shown at Figure 1, 2, 3, 4, 5 and 6 comprises a carton which is - in formed of a blank shown at Figure 1 where the carton has a floor panel 11, two end panels 12 and 13 and two side panels 14 and 15. Each of the end panels 12 and 13 and each of the side panels 14 and 15 are provided with an outer extension panel 16, 17, 18 and 19 respectively which when the carton is erected combine to provide the closure for the carton. Each of the end panels 12 and 13 and the side panels 14 and 15 are formed integrally with the floor panel 11 and are connected to the floor panel 11 by a fold line whereby they can be folded to be substantially perpendicular to the floor panel 11 which will bring their adjacent side edges into abutment with each other.

The side edges of the side panels 14 and 15 and their extension panels 18 and 19 are provided with glue flaps 20 which are adapted to be able to overlie the edge portions of the inner faces of the adjacent end panels 12 and 13 and their respective extension panels 16 and 17 when the side panels and end panels are folded along their fold line with the floor panel 11 as described above. The glue flaps 20 may be rendered self adherent such that they will adhere to the edge portions of end panels 12 or 13 or may have an adhesive applied thereto prior to folding to effect such adhesion. As a result of the fixing of the glue flaps 20 to the end panels 12 and 13 and their respective extension panels 16 and 17 the junctions between the end panels 12 and 13 and the side panels 14 and 15 and between the respective extension panels are sealingly closed.

Each of the end panels 12 and 13 are provided with a pair of first diagonal fold lines 21 and 22 which extend from the junction between the adjacent edges of the end panel and the adjacent side panel and terminate at the central axis of the end panel whereby the diagonal fold lines 21 and 22 are perpendicular to each other.

Li addition in the case of the first embodiment the floor panel 11 is provided with a first central fold line 23 which is centrally located and extends between the end panels 12 and 13. Each of the end panels 12 and 13 and the respective extension panels 16 and 17 are formed with a second central fold line 24 which is co-linear in the folded blank shown in Figure 1 with the first central fold line of the floor panel 11.

In addition each of the extension panels 16 and 17 on the end panels 12 and 13 are provided with a pair of second diagonal fold lines 25 and 26 which are parallel to the first diagonal fold lines 21 and 22. The second diagonal fold lines 25 and 26 extend from the junction between the respective end panel and the extension panel to converge and terminate at the outer edge of the extension panel.

In the formation of the carton from the blank, the side panels 14 and 15 and the end panels 12 and 13 are folded to be substantially perpendicular to the floor panel 11 which brings the glue flaps 20 into face to face engagement with the adjacent edge portions of the inner faces of respective end panels 12 and 13 and their extension panels 16 and 17. Figure 2 illustrates the carton partially erected where one end panel 12 and its extension panel 16 has been folded with the adjacent side panel 14 and its extension panel 18 to be perpendicular to the floor panel 11. The glue flaps 20 on the side panels 14 and 15 and their extension panels 18 and 19 are then bonded to the respective end panels 12 and 13 and their extension panels 16 and 17 to define a substantially cubic carton as shown at Figure 3 where the extension panels 16, 17, 18 and 19 are open. Once erected the side panels, end panels and floor panel of the formed carton define a liquid tight space whereby the folded junctions between the floor panel and each of the side panels and end panel is substantially continuous and is closed and the junctions between the side panels and the end panels are also continuous and sealed.

The floor panel 11 is bound by a perimeter P that comprises in the erected carton, edges or junctions between each of the end panels 12, 13 and the side panels 14, 15; and, the floor panel 11. Further, in the erected carton a first or lowermost edge of the end panels 12, 13 and side panels 14, 15 lie on the same plane as the floor panel 11, as is self evidence from Figures 2 - 6. Thus when the erected carton is sitting on a support having a planar surface such as a table, in its normal use position, the floor panel 11 will lay flat on and in face to face contact with the planar surface.

In some embodiment glue flaps are used to fasten side or end panels to the floor panel 11. It may be more aesthetically pleasing to have the glue flaps glued to the inside of the floor panel 11. Indeed this may be the case for all glue flaps, so that from the exterior of a closed carton, no glue flaps are visible. From a view point of operation of the carton the glue flaps can be glued to the outside (ie underside) of the floor panel, or any other panel to which the glue flaps are to be glued. It will be appreciated that when any glue flap to be glued to the floor panel 11 is glued to the outside (ie underside) of the floor panel, the floor panel will still lay flat on and be in face to face contact with the support surface on which it sits, with the first or lower most edges of the side and end panels remaining in the same plane as the floor panel.

Furthermore, the carton can be readily folded to a substantially flat condition as shown at Figure 6. This is effected by causing the first central fold line 23 of the floor panel 11 to fold such that the first central fold line 23 moves inwardly. In addition the first diagonal fold lines 21 and 22 of each of the end panels to move inwardly to lie between the side panels 14 and 15 to overlie the portions of the floor panel 11 to each side of the first central fold line 23 and the portion of the second central fold line 24 between the junction of the first diagonal fold lines 21 and the junction between the respective end panel 12 and 13 and the floor panel 11 moves to overlie the first central fold line 23. In addition the portion of the second central fold line 24 between the junction of the first diagonal fold line 21 and the outer edge of the extension panel 16 and 17 folds such that it moves inwardly to lie between the side panels 14 and 15. This action brings the side panels together with the folded floor panel 11 and folded end panels 16 and 17 located there between as shown at Figure 6.

When the carton is in the erected condition as shown at Figure 3 the carton can be closed by causing the second diagonal fold lines to fold such that the inner faces of the extensions 17 and 16 end panels to each side of the second diagonal fold lines 25 and 26 fold inwardly about the second diagonal fold lines towards each other as shown at Figure 4. As a result the extensions 17 and 16 of the end panels fold outward from each end of the carton which serves to bring the extensions 18 and 19 on the side panels 14 and 15 towards each other to overlie the space created by the carton between the floor panel, the side panels and the end panels. The folded extensions of the end panels can then be folded downwardly about the fold line defined between the junction of each end panel 12 and 13 and its respective extension 16 and 17 whereby the folded extension lies closely adjacent and substantially parallel to the outer face of the respective end panel as shown at Figure 5. Also the floor panel 11 and the junctions of the floor panel 11 and the end and side panels 12, 13, 14 and 15 lie on a common plane.

It has been found that because of the construction of the carton where end panels, the side panels and the floor panel are all fixed together and are closed (i.e. formed without any holes, slots or openings) that on attempting to hinge the folded extension panels 16 and 17 about their junctions with the respective end panels 12 and 13 from the lateral position as shown at Figure 4 to a locked position parallel and alongside the end panels as shown at Figure 5, an initial biasing force is generated by the carton and applied to the folded extension panel as it moves to the locked position resisting its movement to the locked position. However, at an intermediate stage of that movement the initial force is replaced by a contrary biasing force generated by the carton which causes the folded extension panel to move towards the end panel and thus be retained at the locked position. To move the folded extensions from the locked position requires the external application of sufficient force to counteract the contrary biasing force. Thus the carton 10 can be closed and retained in the closed condition without the application of any other means or action. This provides the "snap" lock facility where the carton snap closes and is self held in a closed condition after folding the extension panels 16 and 17 through an intermediate angle below their lateral (horizontal) positions.

In the case of the second embodiment as shown at Figures 7 to 11 the carton is of a generally similar form to that of the first embodiment with the exception that in the case of the side panels 214 and 215 the edges are not provided with glue flaps but rather the edges of the end panels 212 and 213 are interconnected with the adjacent edges of the adjacent side panels 214 and 215 by a web element 227 which has an outer edge which is disposed at substantially 45° to the edges of the respective end panel and side panel. In addition the webs 227 are each provided with a third diagonal fold line 228 which extends from the junction between the adjacent edges of the adjacent end panel and side panel where the third diagonal fold line 228 bisects the angle between the adjacent end panel and side panel.

In addition the side edges of the extensions 216 and 217 of the end panels 212 and 213 are provided with glue flaps 220 which are adapted to be able to overlie the edge portions of the inner faces of the adjacent extension panels 218 and 219 of the side panels 214 and 215 when the side panels and end panels are folded along their fold line with the floor panel 211. The glue flaps 220 may be rendered self adherent such that they will adhere to the edge portions of extension panels 218 and 219 of the side panels 214 and 215 or may have an adhesive applied thereto prior to folding to effect such adhesion. As a result of the fixing of the glue flaps 220 to the extension panels 218 and 219 the junctions between the extension panels on the side panels 214 and 215 and the end panels 212 and 213 are sealingly closed.

In folding the blank to form the erected carton as shown in Figure 8 each web 227 is folded about the junction between the respective end panel and side panel and the third diagonal fold line 228 is caused to fold and move inwardly such that the web is folded and lies within the carton adjacent the respective side wall, to be bonded thereto.

The erected carton can then be folded into flat condition as shown at Figure 11 in the same manner as has been described in relation to the first embodiment. In addition the erected carton can be closed in the same manner as has been described in relation to the first embodiment and as shown at Figures 9 and 10 with the same locking action as described in relation to the first embodiment.

The third embodiment as shown at Figures 12 to 16 is of generally similar form to the first and second embodiment in terms of the configuration of the erected carton as shown at Figure 13. The difference in relation to the third embodiment relates to the configuration of the blank as shown at Figure 13 in that the end panels 412 and 413 are interconnected with one or the other side panel 418 or 419 respectively. When the carton has been formed from the blank as shown at Figure 13 it can be folded and collapsed in a similar manner to that of the first and second embodiment as shown at Figure 16 and can be closed in a similar manner to that of the first and second embodiment as shown at Figures 14 and 15 with the same locking action as described in relation to the first embodiment.

The fourth embodiment of Figures 17 to 21 comprises a carton which is of generally similar form to the first and second embodiment in terms of the configuration of the erected carton as shown at Figure 18. The carton is formed from a blank where each of the side panels 614 and 615 and their extensions supports a portion of each end panel and then- extensions which when the carton is erected combine to form the end panels. When the carton has been formed from the blank as shown at Figure 18 it can be folded and collapsed in a similar manner to that of the first, second and third embodiment as shown at Figure 21 and can be closed in a similar manner to that of the first and second embodiment as shown at Figures 19 and 20 with the same locking action as described in relation to the first embodiment.

The fifth embodiment of Figures 22 to 26 is of a similar form to that of the third embodiment of Figures 17 to 21 with the exception that the adjacent edges of the portions of the end panels 712a, 712b, 713a and 713b and the floor panel 711 are interconnected by web members 727 having an edge which is at 45 degrees to the respective edges of the portion of the respective end panel and the floor panel. Each web 727 is provided with a third diagonal fold line 728 extending from the junction between the respective portion of the end panel and the floor panel and which bisects the angle therebetween, hi formation of the carton the web panels 727 are folded inwardly as a result of the third diagonal fold line folding inwardly into the interior of the carton whereby on the carton being erected the folded web 727 lies against the end panel and is glued thereto. When the carton has been formed from the blank as shown at Figure 23 it can be folded and collapsed in a similar manner to that of the first, second, third and fourth embodiment as shown at Figure 26 and can be closed in a similar manner to that of the first and second embodiment as shown at Figures 24 and 25 with the same locking action as described in relation to the first embodiment.

The sixth embodiment of Figures 27 and 28a to 28g is of very similar form to the first embodiment as shown at Figures 1 to 6 and the same reference numerals have been used in respect of corresponding features. The only difference is that the sixth embodiment includes a transverse fold line 30 formed in each of the end panels 12 and 13 and which extends from the point of intersection of the first diagonal fold lines 21 and 22 to one side of each end panel 12 and 13. The transverse fold line facilitates the folding of the blank to form a carton. The steps involved in forming the carton are illustrated at Figures 28a to 28g.

The first step involves folding the glue flaps 20 provided on the side panel 15 and extension panel 19 which are remote from the transverse fold line 30 inwardly such that they overlie the respective panel 15 and 19 respectively as shown at Figure 28a. The second step involves folding each end panel 12 and 13 about the first diagonal folds lines 21 and 22 and simultaneously folding the end panel 12 and 13 about the transverse fold line 30 to cause the outer portion of each end panel to underlie the portion of the end panel defined by the first diagonals 21 and 22 as shown at Figure 28b. The third step involves folding the glue flaps 20 provided on the side panel 14 and extension panel 18 which are proximate the transverse fold line 30, inwardly such that they overlie the respective panel 14 and 18 respectively as shown at Figure 28c. The fourth step involves folding each end panel 12 and 13 about the junction with the floor panel 11 such that the end panels 12 and 13 in their entirety overlie the floor panel 11 as shown at Figure 28d. The fifth step involves folding the side panel 15 which is remote from the transverse fold line 30 about the junction with the floor panel 11 after the exposed faces of the glue flaps 20 of that side panel and its extension panel 19 have been rendered such that they will adhere to the opposed faces of the end panels 12 and 13 as shown at Figure 28e. The sixth step involves folding the blank as folded to that point in time about the central fold line 23 in the floor panel 11 as shown at Figure 28f. The final step involves folding the side panel 14 which is proximate the transverse fold line 30 about the junction with the floor panel 11 after the exposed faces of the glue flaps 20 of that side panel and its extension panel 18 have been rendered such that they will adhere to the opposed faces of the end panels 12 and 13 as shown at Figures 28g. The resultant folded blank will take the form as shown at Figure 6 in relation to the first embodiment and can be opened to form an erected carton as shown at Figure 3 in relation to the first embodiment and can be folded in the same manner as is described in regard to the first embodiment and as shown at Figures 4 and 5 with the same locking action as described in relation to the first embodiment.

The above folding sequence in relation to the sixth embodiment is given by way of example only. The folding sequence can vary depending upon the nature of the folding facilities that are available. Figures 29a - 29c depict a blank 800 and initial folding steps for constructing a seventh embodiment of the carton from the blank 800. In this embodiment the carton is reinforced by the provision of glue flaps that extend along the inside of side panels 14 and 15. In comparison with the first embodiment shown in Figures 1 - 6, the seventh embodiment of the carton made from the blank 800 shown in Figures 29a - 29c differs by relocation of the glue flaps 20 from the side extension panels 18 and 19 to the end extension panels 16 and 17 respectively, and relocation and reconfiguration of the glue flaps 20 on the side panels 14 and 15 to constitute new glue panels 820a and 820b that extend laterally from opposite sides of the end panels 12 and 13 respectively. The glue panels 820a and 820b are formed of a length approximately one half the length of the side panels 14 and 15. When the carton is being erected the glue panels 820a and 820b are glued to the inside of the side panels 14 and 15 with respective free ends F of the glue panels 820a and 820b meeting or otherwise being closely adjacent approximately mid way along the length of the side panels 14 and 15. This in effect provides the erected carton with side walls of double thickness and thus double strength.

Each of the glue flaps 820a, 820b has a proximal portion 821 that tapers inwardly from opposite edges in an identical manner to the glue flaps 20, and a contiguous second portion 822 having a transverse dimension TA that is less than the transverse dimension TB (corresponding with the height of) the side panels 14 and 15.

Apart from the location of the glue flaps and the consequential changing in the panels to which the glue flaps are attached, the construction of a carton from the blank 800 is identical to that described above in relation to the first embodiment depicted in Figures 1 —

6. The end carton will, have an identical exterior appearance and operation to the carton shown in Figures 4 - 6.

A similar effect may be provided by modifying the embodiment shown in Figure 12 by reconfiguring the glue flaps 420a and 420b as glue flaps 420ma and 420mb as shown in phantom in Figure 12. In this modification the glue flaps 420ma and 420 mb are each of substantially the same length of the side panels and 414 and 415. Thus in the erected carton, the panel 420ma is glued to an inside surface of the side panel 415 and glue flap 420mb is glued to the inside surface of side panel 414. Otherwise, the construction and operation of a carton from the modified blank is identical to that as described hereinbefore in relation to the embodiment shown in Figures 12 - 16.

It should be appreciated that the scope of the present invention need not be limited to the particular scope of the embodiments described above.

Throughout the specification, unless the context requires otherwise, the word "comprise" or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

Claims

CLAIMSWhat is claimed is:

1. A collapsible carton which is formed from a blank having a peripheral boundary edge and being continuous within the peripheral boundary edge, the carton when formed from the blank is capable of being folded between a folded flat condition and an erect condition whereby when in the erect condition the carton comprises: a floor panel; two opposed end panels; and two opposed side panels to define a generally rectangular prismatic shaped space, wherein the end panels and the side panels have substantially the same height, wherein the floor panel has a perimeter formed from a junction between the floor panel and each of the side panels and each of the end panels, the junction being liquid-tight, wherein the end panels each have a pair of first diagonal fold lines extending from the junction between the sides of the floor panel and the sides of the respective end panel and converging to terminate at a transverse central axis of the end panel, the pair of first diagonal fold lines being substantially perpendicular to each other, the end panels have a height being equal to or greater than the termination of the first diagonal fold lines, wherein the floor panel is provided with a first central fold line which is substantially centrally located and which extends between the end panels and is adapted to permit the floor panel to fold inwardly into the space about the first central fold line while the first diagonal fold lines fold, ' wherein the end panels have a second central fold line extending centrally from the floor panel to an opposed edge of the end panels, wherein each end panel and each side panel is formed with an integral extension panel, being of substantially the same height as its respective end panel or side panel, wherein in the erected carton an abutting edge of adjacent extension panels are defined by a closed fold line, wherein the extension panels of each end panel each have a pair of second diagonal fold lines extending between the junction between the end panel and the extension panel at the sides thereof and converging to terminate at the junction of the second diagonal fold lines with an outer edge of the extension panels, whereby on the erection of the carton the extension panels of each end

^• panel fold about the second diagonal fold lines and the junction with the end panels to an intermediate position where the extension panels of the side panels fold over the space to close the space and lie substantially parallel to the floor panel, wherein the extension panels of the end panels are foldable about their junction with their respective end panels to lie substantially parallel to and adjacent their respective end panels on an outside of the space in a self locked position where a biasing force is applied to the extension panels of the first side panels in a direction of their respective first side panels, and wherein the floor panel, side panels and end panels are relatively configured whereby when the carton is supported on a planar support surface the floor panel is in face to face contact with the planar surface. / ;

2. The carton according to claim 1, wherein each of the end panels and each of the side panels have respective lower edges that when joined with the perimeter of the floor panel form the junction.

3. The carton according to claim 1, wherein the blank further comprises a plurality of glue flaps, the glue flaps being glued to an inside surface of the side panels and overlaying substantially the whole length of the side panels.

4. The carton according to claim 3, comprising four of the glue flaps wherein each glue flap is of a length being one half of the length of an adjacent side panel whereby two glue flaps are glued to each of the side panels.

5. The carton according to claim 3, wherein each glue flap comprises a main portion having a transverse dimension less than the height of the side panels.

6. The carton according to claim 5, wherein each glue flap extends from an end panel.

7. The carton according to claim 6, wherein each glue flap has a proximal portion adjacent a respective end panel from which the glue flap extends, the proximal portion being contiguous with the main portion and tapering in transverse dimension from a height equal to the height of the side panels to the height of the main portion.

8. The carton according to claim 1, in the blank, the side panels are hingedly supported from opposite edges of the floor panel through a fold line.

9. The carton according to claim 1, wherein in the blank, the side panels are hingedly supported from the floor panel and the end panels are hingedly supported from the side panels.

10. The carton according to claim 8, wherein in the blank one end panel is supported from one of the side panels and a second end panel is supported from a second side panel.

11. The carton according to claim 1, wherein in the blank, each side panel supports a portion of each end panel whereby adjacent portions of the end panels cooperate to define at least one of the end panels when the blank is folded to an erect condition.

12. A collapsible carton which is formed from a blank having a peripheral boundary edge and being continuous within the peripheral boundary edge, the carton when formed from the blank is capable of being folded between a folded flat condition and an erect condition whereby when in the erect condition the carton comprises: a floor panel; two opposed end panels; and two opposed side panels to define a generally rectangular prismatic shaped space, wherein the end panels and the side panels have substantially the same height, wherein the floor panel has a perimeter formed from a junction between the single floor panel and each of the side panels and each of the end panels, the junction being liquid-tight, wherein the end panels each have a pair of first diagonal fold lines extending from the junction between the sides of the floor panel and the sides of the respective end panel and converging to terminate at a transverse central axis of the end panel, the pair of first diagonal fold lines being substantially perpendicular to each other, the end panels have a height being equal to or greater than the termination of the first diagonal fold lines, wherein the floor panel is provided with a first central fold line which is substantially centrally located and which extends between the end panels and is adapted to permit the floor panel to fold inwardly into the space about the first central fold line while the first diagonal fold lines fold, wherein the end panels have a second central fold line extending centrally from the floor panel to an opposed edge of the end panels, wherein each end panel and each side panel is formed with an integral extension panel, being of substantially the same height as its respective end panel or side panel, wherein in the erected carton an abutting edge of adjacent extension panels are defined by a closed fold line, wherein the extension panels of each end panel each have a pair of second diagonal fold lines extending between the junction between the end panel and the extension panel at the sides thereof and converging to terminate at the junction of the second diagonal fold lines with the outer edge of the extension panels, whereby on the erection of the carton the extension panels of each end panel fold about the second diagonal fold lines and the junction with the end panels to an intermediate position where the extension panels of the side panels fold over the space to close the space and lie substantially parallel to the floor panel, wherein the extension panels of the end panels are foldable about their junction with their respective end panels to substantially parallel to and adjacent their respective end panels on an outside of the space in a self locked position, wherein the floor panel, side panels and end panels are relatively configured whereby when the carton is supported on a planar support surface the floor panel is in face to face contact with the planar surface, and wherein, the blank comprises a plurality of glue flaps where respective glue flaps are glued to an inside surface of the side panels and overlay substantially the whole length of the side panels.

13. The carton according to Claim 14 wherein in the blank, each of the first end portions and second end portions is provided with one of the first diagonal fold lines.

14. The carton according to Claim 15 wherein in the blank, each of the first end extension portions and second end extension portions is provided with one of the second diagonal fold lines.

15. The carton according to Claim 14 further comprising a triangular web extending between each of the first and second end portions and respective adjacent edges of the floor panel.

16. The carton according to Claim 17 wherein each triangular web comprises a bisecting fold line.

17. The carton according to claim 12, comprising four of the glue flaps wherein each glue flap is of a length being one half of the length of an adjacent side panel whereby two glue flaps are glued to each of the side panels.

18. The carton according to claim 12, wherein each glue flap comprises a main portion having a transverse dimension less than the height of the side panels.

19. The carton according to claim 18, wherein each glue flap extends from an end panel.

20. The carton according to claim 19, wherein each glue flap has a proximal portion adjacent a respective end panel from which the glue flap extends, the proximal portion being contiguous with the main portion and tapering in transverse dimension from a height equal to the height of the side panels to the height of the main portion.

21. A collapsible carton comprising: a floor panel, two opposite first side panels, and two opposite second side panels, the panels together defining a generally rectangular prismatic shaped space, wherein the first side panels and the second side panels have substantially the same height, wherein the floor panel has a perimeter formed from a junction between the floor panel and each of the first and second side panels, the junction being liquid tight, wherein each of the first side panels and each of the second side panels is formed with an integral extension panel, the extension panels being of substantially the same height as its respective side panels, wherein in the erected carton an abutting edge of adjacent extension panels is defined by a closed fold line, the extension panels together forming a self locking closure being foldable to fully closed position where the extension panels of the second side panels fold over the space to close the space and lie substantially parallel to the floor panel, and the extension panels of the first side panels are foldable to lie substantially parallel to the and adjacent their respective first side panels on an outside of the space in a self locked position where a biasing force is applied to the extension panels of the first side panels in a direction of their respective first side panels, and a plurality of glue flaps extending from the first side panels, the glue flaps being glued to an inside surface of the second side panels and overlying substantially the whole length of the second side panels.

22. The carton according to claim 21, comprising four of the glue flaps, wherein each glue flap is of a length being one half of the length of an adjacent second side panel whereby two glue flaps are glued to each of the second side panels.

23. The carton according to claim 21 wherein each glue flap comprises a main portion having a transverse dimension less than a transverse dimension of the second side panels.

24. The carton according to claim 23, wherein each glue flap has a proximal portion adjacent a respective first side panel from which the glue flap extends, the proximal portion being contiguous with the main portion and tapering in transverse dimension from a transverse dimension equal to the transverse dimension of the second side panels to the transverse dimension of the main portion.

25. The carton according to claim 21 wherein the first side panels each comprise a first pair of first diagonal fold lines extending from the junction between the sides of the floor panel and the sides of the respective first side panels and converging to terminate at a transverse central axis of each of the first side panels, the pair of first diagonal fold lines being substantially perpendicular to each other, the first end panels having a height equal to or greater than the termination of the first diagonal fold lines.

26. The carton according to claim 25, wherein the floor panel comprises a first central fold line which is substantially centrally located and extends between the first side panels and is adapted to permit the floor panel to fold inwardly into the space about the first central fold line while the first diagonal fold lines fold.

27. The carton according to claim 26, wherein the first side panels have a second central fold line extending centrally from the floor panel to an opposite edge of the first side panels.