EP1661814A1

EP1661814A1 - Container

Info

Publication number: EP1661814A1
Application number: EP05077519A
Authority: EP
Inventors: Dietmar Pavel; Walter Ramspott
Original assignee: Unilever PLC; Unilever NV
Current assignee: Unilever PLC; Unilever NV
Priority date: 2004-11-26
Filing date: 2005-11-03
Publication date: 2006-05-31
Anticipated expiration: 2025-11-03
Also published as: MXPA05012602A; AU2005237171A1; BRPI0505214A; AU2005237171B2; DE602005017344D1; ATE446912T1; ES2332521T3; EP1661814B1

Abstract

A blank for assembly into a container, the blank comprising a base panel (32), a first wall panel (34) attached to the base panel via a first fold line, a second wall panel (36,38) attached to the base panel via a second fold line, and a flap panel attached to the first wall panel, the blank further comprising first locking means comprising slit means (70) on the second wall panel (36) and a first locking member (80) on the flap panel (34), the blank further comprising second locking means comprising slot means (110) on one of the second wall panel or flap panel, and a second locking member on the other of the second wall panel or flap panel; wherein a portion of the first locking member (100) may engage with the slit means, and a portion of the second locking member may engage with the slot means, whereby the first and second wall panels are held together. Preferably, the second locking member comprises a head and a stem, the head having a greater maximum width than the stem, the head being positioned adjacent the edge of the panel distal from the base panel, and the stem extending from the head towards the base panel.

Description

The present invention relates to a container and in particular to a container which may be formed by the automated folding of a blank.
Cardboard and paperboard containers are typically formed from a flat blank that is folded together in an automated process to give a finished product. It is often necessary to form a corner of a tray or box-like container by folding two wall panels into upright configurations and then locking them together. One way to lock wall panels together to form such a corner is disclosed in EP 0 016 879. The locking mechanism disclosed in EP 0 016 879 is described below with reference to Figures 1 and 2. Although this prior art system allows for automated formation of containers with interlocked corners, prior art systems such as this still suffer from a number of disadvantages.
Although the system in EP 0 016 879 allows wall panels to be connected together to form a corner, the locking mechanism can work loose and become undone whilst the container is being transported or handled, particularly by the end consumer. When the locking mechanism is becoming loose, the wall panels can splay outwards to give an unattractive appearance to the container. Furthermore, articles or products stored within the container can escape if the wall panels become unlocked from each other.
There exists a need therefore for an improved container that may be formed from a blank in an automated process. In particular, there exists a need for an improved locking mechanism for a corner of such a container.
The present invention seeks to provide an improved container, a blank for such a container and method for forming a container from a blank.
According to one aspect of the present invention there is provided a blank for assembly into a container, the blank comprising a base panel, a first wall panel attached to the base panel via a first fold line, a second wall panel attached to the base panel via a second fold line, and a flap panel attached to the first wall panel, the blank further comprising first locking means comprising slit means on the second wall panel and a first locking member on the flap panel, the blank further comprising second locking means comprising slot means on one of the second wall panel or flap panel, and a second locking member on the other of the second wall panel or flap panel; wherein a portion of the first locking member may engage with the slit means, and a portion of the second locking member may engage with the slot, whereby the first and second wall panels are held together.
Preferably, the slit means comprises a slit having a first segment substantially perpendicular to the second fold line, a second segment substantially to the second fold line and a third segment joining the first and second segments, the ends of the third segment defining a first acute angle with respect to the second fold line, the first locking member having a first edge portion substantially perpendicular to the first fold line and a second edge portion provided at a second acute angle to the first edge portion, wherein the first locking member is adapted to be inserted through the slit means such that the second edge portion of the first locking member engages with the third segment of the slit means to hold the first and second wall panels together.
Conveniently, the third slit segment is substantially straight.
Advantageously, the third slit segment is arcuately shaped.
Preferably, said arcuately shaped third slit segment has a convex side directed towards the base panel.
Conveniently, the first acute angle no greater than about 40°, and the second acute angle is at least about 45°.
Advantageously, the second locking member comprises a head and a stem, the head having a greater maximum width than the stem, the head being positioned adjacent the edge of the panel distal from the base panel, and the stem extending from the head towards the base panel.
Preferably, the first locking member has a truncated arrow shape.
Conveniently, the slot means has a width less than the maximum width of the head of the second locking member.
Advantageously, the slot means is provided on the second wall panel and the second locking member is provided on the flap panel.
Preferably, the slot means is provided on the flap panel and the second locking member is provided on the second wall panel.
Conveniently, the blank has a right-angled corner.
Advantageously, the blank has an arcuate corner.
Preferably, the blank has a corner having an angle of about 120°.
Conveniently, the blank has a corner having an angle of about 135°.
Advantageously, the blank has a fold line between the flap panel and first wall panel.
Preferably, the blank has four sets of first and second locking mechanisms.
According to another aspect of the present invention, there is provided a container formed from a blank as defined above.
According to a further aspect of the present invention, there is provided a method of forming a container from a blank comprising providing a blank as defined above, inter-engaging the first locking member with the slit means, and inter-engaging the second locking member with the slot means to form a corner.
Preferably, the method further comprises the addition of an article to the container.
Conveniently, the method further comprises the step of attaching a lid to the container.
The present invention will now be described, by way of example, with reference to the accompanying Figures in which

Figure 1 is a partial plan view of a blank for a container according to the prior art,
Figure 2 is a partial cross-sectional view of a container formed from the blank shown in Figure 1,
Figure 3 is a plan view of a blank for a container in accordance with the present invention,
Figure 4 is a partial plan view of the blank shown in Figure 3 showing the locking mechanisms,
Figure 5 is a partial cross-sectional view of a container formed from the blank shown in Figure 4 in an initial stage of locking,
Figure 6 is a view according to Figure 5 in an intermediate stage of locking
Figure 7 is a view according to Figure 5 in a final stage of locking, and
Figure 8 is a perspective view of a container formed from the blank shown in Figure 3.

Turning to Figure 1, the prior art locking mechanism disclosed in EP 0 016 879 is shown. Figure 1 shows a cardboard blank 2 of substantially planar configuration ready for automated assembly to form a three-dimensional container. The blank 2 comprises a piece of paperboard with a predefined cut out edge with a number of slots already formed in various portions of the blank, along with predefined score lines. As will be described below, the various cut out edges, slots and score lines allow for automated folding and locking processes leading to a final three-dimensional container.
Figure 1 shows one corner of a base panel 4 of generally square shape having a first wall panel 6 extending along one edge. The wall panel 6 is attached to the base panel 4 by a substantially straight scored fold line 8. A second wall panel 10 is provided on an adjacent side of the base panel 4, attached thereto by a second fold line 12. A locking flap 14 extends from the end of the first wall panel 6 adjacent the second wall panel 10. The locking flap 14 is separated from the first wall panel 6 by a third fold line 16, which is an extension of the second fold line 12. The free end of the locking flap 14 is shaped to provide a pointed locking member 18. The shaped locking member 18 forms one part of a locking mechanism used to connect the first wall panel 6 and the second wall panel 10 together. The second part of the locking mechanism is a slit 20 formed on the second wall panel 10. The slit 20 comprises a first straight segment 22 that is substantially parallel to the second fold line 12. The slit 20 also comprises a second straight portion 24 that extends substantially perpendicularly to the second fold line 12. The first segment 22 and the second segment 24 of the slit 20 are joined together by an arcuate third segment 26 having a convex portion projecting towards the base panel 4.
EP 0 016 879 describes in detail the way in which the locking mechanism shown in Figures 1 and 2 may be engaged in an automated process. The disclosure of EP 0 016 879 is therefore incorporated herein by reference for further details of the locking mechanism.
In general, the second wall panel 10 is folded along the second fold line 12 to a position substantially perpendicular to the base panel 4. The locking flap is bent over the third fold line 16 and the first wall panel 6 is then folded along the first fold line 8 such that the locking member 18 is inserted through the slit 20. The tip of the locking member 18 is pushed under the first segment 22 of the slit 20 in a process known as "stripping", which involves the use of an automated arm or tongue.
The final position of the locking mechanism is shown in Figure 2, which is a partial cross-sectional view of the assembled locking mechanism when viewed from the interior of the container. The locking member 18 has been inserted through the slit 20 and is retained in this position in the interior of the container by engagement between the upper surface of the locking member 18 and the edges formed by the first segment 22 and third segment 26 of the slit 20.
This prior art locking mechanism allows for rapid automated assembly to give a container with a relatively robust corner. However" under certain circumstances, during folding, the roundness of the corner can be altered leading to unwanted consequences.
A blank according to the present invention is shown in Figure 3 generally at 30. The blank is made of a sheet of paperboard that has been cut into a specific shape and provided with score lines and slits (otherwise known as a die-cut carton blank). The blank 30 is designed to be assembled in an automated process to initially give an open tray with a hinged lid that may be filled with articles. After filling, the hinged lid is then folded over the open face of the tray and sealed to give a finished, filled carton.
The carton blank comprises a base panel 32 that forms the floor of the finished carton. The base panel 32 is of substantially square shape with arcuate or rounded corners.
Attached to one side of the base panel 32 by a fold line is a first front panel 34. On opposite sides of the base panel 32 are provided left and right side panels 36 and 38, separated from the base panel 32 by fold lines. On the opposite side of the base panel 32 from the first front panel 34 is provided a back panel 40, separated by a fold line from the base panel 32. On the opposite side of the back panel 40 from the base panel 42 is provided a lid panel 42. The lid panel 42 is substantially the same size and shape as the base panel 32. On the opposite side of the lid panel 42 from the back panel 40 is provided a second front panel 44. On the remaining sides of the lid panel 42 are provided left and right side panels 46 and 48. The side panels 46 and 48 and second front panel 44 are separated from the lid panel 42 by fold lines.
The first front panel 34 extends beyond the width of the base panel 32 in both directions. On each free end of the front panel 34 there are provided locking means 50,52. In a similar fashion, the back panel 40 extends beyond the width of the base panel 32 and lid panel 42 in both directions, each free end of the back panel 40 being provided with locking means 54,56.
The side panels 36 and 38 do not extend beyond their point of attachments to the base panel 32. Each free corner area of the side panels 36 and 38 is provided with a locking mechanism 58,60,62,64. The function of the locking mechanisms of the blank 30 is described below in more detail.
Figure 4 shows the bottom left-hand corner of the blank 30 of Figure 3 in more detail. As can be seen, the front panel 34 extends beyond the width of the base panel 32. The free end of the front panel 34 is provided with a first locking member 80 that is defined by a slit 84 that runs from the free end of the front panel 34 in a direction approximately towards the centre of the base panel 32. The angle between the slit 84 and the free edge of the front panel 34 is about 40°. The slit 84 thus defines the locking member 80 having a tip 82, a front edge 86 leading downwards away from the tip 82 to meet a corner 88, leading to a bottom edge 90. The angle between the front edge 86 and the bottom edge 90 about the corner 88 is about 120°.
A slit 70 is provided in the side panel 36, comprising a first straight segment 72 substantially parallel to the fold line joining the side panel 36 to the base panel 32. A second straight segment 76 is provided running substantially perpendicularly to the fold line between the base panel 32 and the side panel 36. A third arcuate segment 74 connects the first segment 72 to the second segment 76. The third segment 74 is arcuate and defines a convex portion of the side panel 36 which projects towards the base panel 32. As will be described below, the first locking member 80 and the slit 70 substantially correspond to the prior art locking mechanism disclosed in EP 0 016 879.
There is also provided a second locking mechanism comprising a second locking member 100 provided on the front panel 34 and a slot 110 provided on the side panel 36. The locking member 100 is defined by two slits extending inwardly from the edge of the front panel 34 distal from the base panel 32. The slits define a truncated arrow or mushroom shape having a head 102 near the distal edge of the side panel 34 and a stem 104 extending away from the distal edge. The head 102 has a wider maximum width than the stem 104.
The side panel 36 has a notch or slot 110 provided on the edge distal from the base panel 32. The width of the slot 110 is substantially equal to the width of the stem 104 of the locking member 100, but is narrower than the maximum width of the head 102 of the locking member 100.
In the automated assembly process, the side panel 36 is folded up to a position substantially perpendicular to the base panel 32. The front panel 34 is then folded upwards and the free end of the front panel 34 is moved towards the slit 70. As will be shown below, the free end of the front panel 34 is folded in an arcuate manner to follow the rounded corner of the base panel 32.
Figure 5 shows a partial cross-sectional view from the interior of the partially assembled carton formed from the blank 30. The corner 88 of the locking member 80 has been inserted through the slot 70 to be positioned within the interior of the carton. However, the tip 82 of the locking member 80 is positioned through the first segment 72 of the slot 70 and is positioned on the exterior of the carton. The second locking member 100 is positioned on the exterior of slot 110, in registration therewith.
Figure 6 shows the next stage in the assembly of the carton, with the tip 82 of the locking member 80 having been pushed under and through the first segment 72 of the slit 70. As described in EP 0 016 879, inter-engagement of the various surfaces of the locking member 80 and the slit 70 ensures that the front panel 34 and the side panel 36 are held together to form the corner of the carton. However, in this position, the second locking member 100 is still positioned in registration with but outside the slot 110 in the side panel 36.
Figure 7 shows the final position with the head 102 of the locking member 100 having been pushed through the slot 110 to rest on the interior of the carton. The head 102 of the second locking member 100 abuts against the inner surface of the side panel 36 adjacent the slot 110, holding the side panels 34 and 36 together.
The above-described process is performed on all of the locking mechanisms provided at each corner to give a completed but unsealed carton 120 as shown in Figure 8. The carton 120 has a tray portion 124 formed by the engagement of the base panel 32, front panel 34, back panel 40 and side panels 36 and 38. The carton also has a lid portion 122 formed by the lid panel 42, front panel 44 and side panels 46 and 48. The next step is the insertion of articles or products into the tray portion 124 followed by folding of the lid portion 122 over the tray portion 124 and sealing to give a sealed, filled, carton.
As mentioned above, the free ends of the front panel 34 and back panel 40 are folded around to follow the arcuate corners of the base panel 32. This gives a completed carton with an aesthetically pleasing appearance. Furthermore, the rounded corners avoid a major problem with traditional cuboid cartons. The right-angled corners of traditional cartons have a disadvantage in that they often crumple when subjected to force during manufacture, transport, display and use by the end consumer. In addition to reducing the aesthetic qualities of the finished carton, the crumpled corners can lead to contamination and/or spillage of the contents of the carton. Also, in situations where the contents of the carton are refrigerated or frozen, the rounded corners ensures that stacks of the carton naturally form air circulation channels where their corners meet which improves the efficiency of refrigeration.
The synergistic effect of the two locking mechanisms means that three dimensional cartons can be easily assembled in an automated process to give cartons with corners that are more robust than prior art cartons. This is particularly the case in instances where there is an outward force subjected to the corners. In the example shown in Figure 8, the carton has rounded corners which inherently exert a force on the locking mechanism which would cause prior art locking mechanisms to deform or become undone, causing the carton to splay, twist or fully open. The provision of the second locking mechanism, such as that exemplified by the second locking member 100 and the slot 110 provides a mechanism by which the corner of the carton 120 may be locked in place against these forces. The head 102 may be pushed through the slot 110 in a simple automated process. The combination of the two locking mechanisms ensures that the cartons may be assembled in automated fashion to give a final product that has a robust corner locking mechanism. In addition to its use on arcuate corners such as that shown in Figure 8, the present invention is also applicable to a wide range of other applications. For example, the invention is applicable to right-angled corners, and to other shapes of containers, such as hexagonal or octagonal cartons (having corners of 120° and 135°, respectively). It can also be used in conjunction with containers having rounded corners that are not substantially square, for example, in triangular-shaped cartons with rounded corners.
It is evident to a person skilled in the art that the various members of the locking mechanisms that may be distributed in other arrangements on the blank. For example, in the embodiment shown in Figure 3, the second locking members 100 are provided on the front panel 34 and rear panel 40, whilst the corresponding slots 110 are formed on the side panels 36 and 38. However, the positions of the slots 110 and locking members 100 may be reversed, to give an alternative blank having locking members 100 provided on the side panels 36 and 38, and slots 110 provided on the front panel 34 and rear panel 40. Also, the invention is applicable to locking members having shapes and configurations different from the specific shape and configuration of the members 100 and slots 110.
In addition, the blanks used to make the cartons of the invention may also be provided with other slots, slits, fold lines and perforations. For example, perforations may be provided in the blank to give a predetermined line or area of weakness that the consumer may easily open to access the contents of the carton. Also, although Figure 8 shows a carton 120 having a lid 122 which is to be glued into position on the tray portion 124, the invention is also applicable to cartons which do not have a lid as such, or to cartons having lids which are attached in ways not involving glue, for example by interlocking members.

Claims

A blank for assembly into a container, the blank comprising a base panel, a first wall panel attached to the base panel via a first fold line, a second wall panel attached to the base panel via a second fold line, and a flap panel attached to the first wall panel, the blank further comprising first locking means comprising slit means on the second wall panel and a first locking member on the flap panel, the blank further comprising second locking means comprising slot means on one of the second wall panel or flap panel, and a second locking member on the other of the second wall panel or flap panel; wherein a portion of the first locking member may engage with the slit means, and a portion of the second locking member may engage with the slot means, whereby the first and second wall panels are held together.
A blank according to Claim 1, wherein the slit means comprises a slit having a first segment substantially perpendicular to the second fold line, a second segment substantially to the second fold line and a third segment joining the first and second segments, the ends of the third segment defining a first acute angle with respect to the second fold line, the first locking member having a first edge portion substantially perpendicular to the first fold line and a second edge portion provided at a second acute angle to the first edge portion wherein the first locking member is adapted to be inserted through the slit means such that the second edge portion of the first locking member engages with the third segment of the slit means to hold the first and second wall panels together.
A blank according to Claim 2, wherein the third slit segment is substantially straight.
A blank according to Claim 2, wherein the third slit segment is arcuately shaped.
A blank according to Claim 4, wherein said arcuately shaped third slit segment has a convex side directed towards the base panel.
A blank according to any of Claims 2 to 5, wherein the first acute angle is no greater than about 40°, and the second acute angle is at least about 45°.
A blank according to any preceding claim, wherein the second locking member comprises a head and a stem, the head having a greater maximum width than the stem, the head being positioned adjacent the edge of the panel distal from the base panel, and the stem extending from the head towards the base panel.
A blank according to any preceding claim, wherein the first locking member has a truncated arrow shape.
A blank according to Claim 7 or Claim 8, wherein the slot means has a width less than the maximum width of the head of the second locking member.
A blank according to any preceding claim, wherein the slot means is provided on the second wall panel and the second locking member is provided on the flap panel.
A blank according to any of Claims 1 to 9, wherein the slot means is provided on the flap panel and the second locking member is provided on the second wall panel.
A blank according to any preceding claim, which has a right-angled corner.
A blank according to any preceding claim, which has an arcuate corner.
A blank according to any preceding claim, which has a corner having an angle of about 120°.
A blank according to any preceding claim, which has a corner having an angle of about 135°.
A blank according to any preceding claim, having a fold line between the flap panel and first wall panel.
A blank according to any preceding claim, having four sets of first and second locking mechanisms.
A container formed from a blank as defined in any preceding claim.
A method of forming a container from a blank comprising providing a blank as defined in any of Claims 1 to 17, inter-engaging the first locking member with the slit means, and inter-engaging the second locking member with the slot means to form a corner.
A method according to Claim 19, further comprising the addition of an article to the container.
A method according to Claim 19 or Claim 20, further comprising the step of attaching a lid to the container.
A blank substantially as hereinbefore described with reference to and as shown in the accompanying drawings.
A container substantially as hereinbefore described with reference to and as shown in the accompanying drawings.
A method for forming a container from a blank substantially as hereinbefore described with reference to and as shown in the accompanying drawings.