GB2427399A

GB2427399A - Blank for container with curved walls

Info

Publication number: GB2427399A
Application number: GB0512644A
Authority: GB
Inventors: Bruce Michael Drew; David Brian Edwards; William John Mccarthy; Michael Edward Parkes
Original assignee: Aquasol Ltd
Current assignee: Aquasol Ltd
Priority date: 2005-06-22
Filing date: 2005-06-22
Publication date: 2006-12-27
Anticipated expiration: 2025-06-22
Also published as: GB2427399B; GB0512644D0

Abstract

A blank for a container comprises floor and roof panels A,I and four side wall panels B,C,D,E. In addition there are further flap panels F,G,H and a locking arrangement comprising a tongue J that cooperates with a slot K. The fold lines between the wall panels and the floor and roof panels are all curved so that when assembled the walls each take on a two-dimensioned concave shape while the roof and floor panels take on three-dimensioned convex shapes. The corners created between adjacent wall panels form acute angles. The number of wall panels can be from 3 to 8. The container may be made from more than one box blank (fig 2). The blank may be produced from any sheet material that can be readily creased and folded but is rigid enough to maintain its shape when formed. The containers are intended to provide increased protection to contents by the strength of the corners and the domed floor and roof panels.

Description

BLANKS FOR CONTAINERS Many designs of blank made from sheet materials and then formed or folded into an assembled container, have been proposed to protect the contents from damage during storage, handling and transport. Some designs have used the architecture of the container to provide increased strength over that of the material from which they are made. In the case of designs such as those described in British Patent Specifications 2,315,060, 2,342,343 and our pending British Patent Application 0427153.2, the increased strength of the assembled container has been provided at least in part by including in the design of the blank a number of arcuate panels, providing strength and durability to the assembled container. The current invention, unlike those mentioned above, comprises a blank which, once assembled into a container, seeks to provide greater strength and resistance to damage of the contents of the container, in all three dimensions and to provide equally high strength around the entire periphery. This may be achieved without sacrificing simplicity of manufacture of the blank, or ease of assembly and closure of the container. The invention therefore relates to a blank designed to be assembled into a container having opposing roof and floor faces and a plurality of between three and eight wall faces of which the wall faces are two dimensionally concave intersecting in plan view to form acute angled comers and in side elevation to form substantially elliptical shapes, and the two opposing roof and floor faces have a three dimensionally convex domed shape, such that all faces of the assembled container are curved in at least two dimensions. The blank is produced by cutting and creasing a sheet material that is rigid enough to maintain its shape after assembly but flexible enough to be readily creased and folded. If the material is difficult to fold, it can be assisted by perforating along the fold lines by blade point, by laser, or by any other method known to persons skilled in the art. Preferably, corrugated fibreboard is used, having a weight of 100-300 grams per square metre (gsm), typically 125-190 gsm. The corrugated fibreboard may be of any fluting format, single wall (including microflutes), double, or triple wall, which lends itself easily to cutting and creasing.It must be noted however that other flat sheet materials can be used to manufacture the blank according to this invention, such as extruded plastic corrugated sheet (for example, that known as Correx ), paper cartonboard, paper folding box board, lightweight metals and various mono or multi-laminated polymeric sheets. When assembled from a blank according to this invention, a typical container has opposing roof and floor faces and a plurality of wall faces extending therebetween, of which the wall faces take a two dimensional concave form and the opposing roof and floor faces take a three dimensional convex domed shape offering particular strength to the container. Thus, a particular feature of the invention is that all faces of the assembled container are curved in at least two dimensions. In one preferred embodiment, the container has four vertical wall faces but this is not essential and the container may have fewer wall faces, for example three, or more wall faces, for example from five to eight. In this preferred embodiment, the blank as shown in figure 1 may be assembled into a container that is square in outline or as shown in figure 1 a into a container that is rectangular in outline. The design of the blank allows the container to be easily and quickly assembled. The method of assembly of the container will now be described with reference to Figure 1. The contents to be packed within the container are first placed upon panel A. Panels D and F on the one side, and panels E and G on the other side are bent along their respective arcuate crease lines until panels F and G form a partial roof over the contents. Panels C and H are now bent along their arcuate crease lines until panel H partially covers both panel F and panel G. Finally, panels B and I are bent along their arcuate crease lines until the closure panel I is in the position shown in figure 1c.The locking slot, into which the locking closure device is inserted, is only revealed at this point in the assembly of the container due to its presence in the blank as a slit K which only opens into a locking slot as the crease on which the locking slot is located is bent through 90 degrees. The locking closure device or devices (the number will depend upon the length of the crease containing slit K) can now be inserted into the locking closure slot or slots, enabling the container to remain closed in its correct shape, as shown in figure 1d. As shown in figure 1d, the assembled container has opposing convex domed roof and floor faces and four concave arcuate vertical wall faces extending between the roof and floor faces around the entire periphery of the container. The term "vertical" is used here to describe the direction parallel to the line between the centre point of the roof face and the centre point of the floor face. Locking devices of any suitable form can be used and it may be advantageous to select locking devices which provide evidence of opening or tampering of the container. Such locking devices are preferably of arrow head shape (as shown at panel J in figure 1) which allows the tongue to be pushed through a corresponding locking slot giving security and tamper evident features. These security features are generally required when the container is to be shipped for example by mail, as many postal services require all packs either to have secure, non-accidentally opening closures or to be secured by means of adhesive or adhesive tape. Where the container is secured with adhesive or adhesive tape, quick locating tongues (non arrow head type) can be used to hold the container closed whilst it is taped or glued with adhesive.It must also be noted that the number of locking devices is dependent upon the length of the edge to be closed. Figure 1 shows only one locking device but more could be added if the crease containing the locking slot K is of sufficient length. Figure lb shows a modification of the design shown in figure 1. In this modification, locking closure devices J are located on panels F and G, instead of on panel I as already described. In this modification, the assembly of the container is similar to that described above except for the closure of the container. In this modification which requires at least two locking closure devices, each locking closure device J is inserted into its own locking slot contained within panel I, thereby holding the container in its closed position. It will be realised that when the container is assembled from a blank of corrugated material as shown in figures 1, 1a or 1c, only opposing vertical concave wall faces present the fluting in a vertical direction, where the term vertical direction is defined as lines parallel to the line between the centre point of the roof face and the centre point of the floor face. However, in a second embodiment of the invention, the design of blank is modified in such a way that after assembly, the fluting of all four vertical concave wall faces will be in a vertical direction, thus offering even greater strength to the container. One example of this embodiment is shown in figure 2. Here, two blanks are used with the fluting direction arranged longitudinally in each, where the term longitudinal is defined as that direction perpendicular to the centre point of the arcuate crease lines of the blank. One blank is placed over the other and at right angles to it, before assembly. With reference to figure 2, the panel T of the first blank (R-S-T-U-V) is placed upon panel A of the second blank (H-C-A-B-I-J) such that the first and second panels are at right angles to each other.At this point, the contents to be packed in the container are placed upon the upper surface of panel T. The first blank is then folded about its arcuate crease lines until panels R and V form a partial roof to the first blank. The second blank is then folded about its arcuate crease lines until panel H can be folded over parts of panels R and V of the first blank. The panel I of the second blank (in this instance the closing panel) is then folded over panel H and the locking closure device inserted into the locking slot K which has been revealed once the second blank has been assembled. A further example of the second embodiment can be seen in figure 2a in which a virtually identical container to that shown in figure 2 can be assembled from a single blank instead of from two separate blanks. Again, the fluting direction has been arranged longitudinally as this term has been defined above. Here, panel D is used as a hinge allowing the panel T to be rotated through 90 degrees and swung over panel A, thereby trapping panel D between panel A and panel T. The remaining filling and assembly procedure follows exactly in accordance with that described above. In a third embodiment of the invention, of particular relevance in cases where it is required to reduce the cost of production of the blank whilst still providing greater vertical strength in the container than that obtained in the first embodiment, the fluting direction in all the wall faces of the blank is at a 45 degree angle to the longitudinal direction. The container is then assembled in an identical manner to that described in the first embodiment. By this means, all the concave wall faces will be equally strong, albeit not as strong as in the second embodiment, but the cost of the additional material required in the second embodiment will have been avoided. It will be seen from figure 1e that an assembled container having six faces, when viewed from a vertical direction, has the appearance of a four pointed star with four acute angled comers which provide an important feature for protecting the contents of the container. When the comers of the assembled container are left empty as will typically be the case, the walls of the comer sections become the first points of contact in any lateral movement of the contents of the container resulting from any applied external force that has a horizontal component. In this way, the contents of the container are protected from direct contact with the external force. The convex domed opposing roof and floor faces provide a similar function against any applied external force that has a vertical component.Furthermore, it will be noticed that where the external force is sufficiently large, the acute angled comers or convex domed opposing roof and floor faces of the container will be crushed before the contents of the container are damaged. The act of crushing the comers or convex domed faces of the container will absorb and dissipate the external force either fully or partially. It is a feature of this invention that the acute angled comers and the convex domed faces of the assembled container are sacrificed in this way in order to offer maximum protection to the contents of the container. It has been found that containers assembled from blanks according to this invention offer greater resistance to impact and crushing due to the plurality of vertical concave wall faces around the entire periphery and the two convex domed roof and floor faces at the base and top of the container respectively as shown in figure 1d. It will be seen that when a relatively flat product is packed within a container made from a blank according to the invention, especially if the product is round or oval, it can be held in position within the container without the need for additional internal packaging. By selecting the dimensions of the blank with this in mind, the periphery of the product will make contact with the assembled container at the internal centre points of each concave face. It will thus be held firmly against internal movement within the container at those points least exposed to external forces, due to the concave shape of the vertical wall faces of the container. A further important protective feature of containers made from blanks according to the invention is the deceleration provided to the contents after the container has been subjected to shock in which acceleration is imparted to the contents due to gravity or other applied force. Any movement of the contents of the container away from the centre of the container will be resisted due to contact of the contents with an internal face of the container. Due to the inherent design of blanks according to this invention, all internal faces of the container will always present an acute angle to the direction of motion of the contents following a shock to the container. Consequently, resistance to the movement will increase more gradually than would be the case if the resisting internal face or faces were perpendicular to the direction of motion.This more gradual increase of forces resisting the movement of the contents allows containers made from blanks according to the invention to offer improved protection from shock to the contents. If the radii of the concave vertical wall faces are chosen with such an objective in mind, the assembled containers will fit together when stacked alternately in horizontal and vertical layers. Such a design provides considerable strength and rigidity to the stack which, once stacked upon a pallet, may be wrapped with film by any means without the need for outer shippers made from corrugated board, typically known as cartons. Eliminating the need for cartons as part of the transit packaging system saves considerable cost. Containers assembled from blanks according to the invention may be of any size provided that the thickness of the sheet material from which the blanks are made has been appropriately chosen. The contents packed in such containers can be of any size or shape and comprise one or more items of similar or different size and shape. It has been found, however, that although the dimensions of the arcuate panels of the blank may differ according to the size of the blank (see, for example, figure 1B), the curvature of the arcuate crease lines in each arcuate panel must be identical in order that the blank can be properly assembled. If it is wished to pack products that, for any reason, require fittings to be present within the container, for example, to provide additional internal support to the contents, this can be done either by means of separate fittings or by means of additional panels at the extremities of the blank which be folded and formed into fittings as the container is assembled. In a fourth embodiment of the invention, the container may have a different number of concave vertical wall faces than four which is the preferred number. Any number of faces equal to, or greater than, three is possible although in practice, as the number of concave vertical wall faces increases, the number of overlapping roof panels also increases and the point is quickly reached where the contribution of each roof panel to the strength of the container has decreased to the point where the cost of so many overlapping roof panels can no longer be justified in protecting the contents from external shock. Figure 3 shows a blank which may be assembled into a container having six vertical concave wall faces and opposing convex domed roof and floor faces.The blank is assembled in a similar way to that described above and the closing panel I held in position by inserting each of five locking closure tongues J into their respective locking closure slots K.

Claims

1. A blank designed to be assembled into a container having opposing roof and floor faces and a plurality of between three and eight wall faces of which the wall faces are two dimensionally concave intersecting in plan view to form acute angled comers and in side elevation to form substantially elliptical shapes, and the two opposing roof and floor faces have a three dimensionally convex domed shape, such that all faces of the assembled container are curved in at least two dimensions.

2. A blank according to claim 1 in which, after assembly, the radius of each of the concave faces is such that the assembled containers can fit together to form a stable stack.

3. A blank according to claims 1 or 2 in which, after assembly, the wall faces extend between the opposing floor and roof faces around the entire periphery of the assembled container.

4. A blank according to any of the preceding claims in which the curvature of both arcuate crease lines of any panel is identical

5. A blank according to any of the preceding claims which, after assembly into a container, due to the plurality of concave vertical wall faces and opposing convex domed roof and floor faces, provides maximal protection and shock resistance of the contained volume per unit area of sheet material from which the blank is made.

6. A blank according to any of the preceding claims, wherein the contents of the assembled container are protected from external impact or pressure in a horizontal direction by means of the container's acute angled comers, and similarly protected in a vertical direction by means of the opposing convex domed roof and floor faces.

7. A blank according to any of the preceding claims, wherein the dimensions are chosen so that the contents of the assembled container are in contact with the centre of each concave face.

8. A blank according to any preceding claim wherein the comers are free to deform or collapse thereby sacrificially absorbing or dissipating impacts and protecting the product.

9. A blank according to any of the preceding claims wherein the assembled container's acute angled corners define a progressively narrowing space in a direction away from the container's geometric centre such that any movement of the contents causes the contents to make contact with an internal surface of the container which is at an incline to the direction of motion causing gradual deceleration of the contents, reducing shock and therefore damage to the contents.

10. A blank according to any of the preceding claims made from corrugated material.

11.A blank according to any of the preceding claims made from any foldable material.

12.A blank according to claim 10 in which the fluting of the corrugated material is disposed at 45 degrees to the longitudinal direction of the blank in each concave vertical wall face such that the strength in a vertical direction of all wall faces is equal.

13.A container assembled from a single blank according to any of claims 1 to 12 in which, during assembly, the blank is folded in such a way that, for corrugated material, the fluting direction of all the concave wall faces is in a vertical direction.

14.A container produced from two or more blanks according to any of claims 1 to 12 in which successive blanks are placed upon the first blank at angles not greater than 90 degrees to each other so that, for corrugated material, the fluting direction of all the concave wall faces is in a vertical direction thereby providing maximum vertical strength.

15.A container assembled from a blank or blanks according to any of claims 1 to 12 in which flaps, provided as extensions to any or all of the panels of the said blank or blanks, can be folded to provide internal supports to restrain the movement of the contents within the closed container or to provide internal structural support to the faces of the said container.

16.A blank according to any one of claims 1 to 12 having from 3 to 8 vertical wall faces.