A BOX

This invention relates to a box of the type used to pack fragile articles, and particularly, but not exclusively to a box for packing lithographic printing plates.

Lithographic printing plates are generally rectangular or square in shape, and very thin in cross-section. When packing such plates for transit, it is important to ensure that the plates cannot become damaged.

It is known to pack printing plates in a box, cardboard and wood, having a shape similar to the shape of the plate. The plates are held in place by pieces of polystyrene. A middle portion of the insert is cut out to leave a cavity in which the plates are positioned. The cavity is shaped to snugly receive the plates such that little movement is possible during transit.

A problem with this known box is that the process of fitting the polystyrene pieces into the box is time consuming, and therefore expensive. In addition, the polystyrene is harmful to the environment in that it is not recyclable.

According to the invention there is provided a box adapted to receive articles for storage or transit, the box comprising: a box forming blank comprising a base portion defined by a first pair of oppositely disposed fold lines, and a second pair of oppositely disposed fold lines, a first pair of flaps extending from the first pair of fold lines respectively, and a second pair of flaps extending from the second pair of fold lines respectively; a retaining insert for retaining the one or more articles, which insert is shaped to be attachable to the base portion of the blank.

An object to be stored or transported, for example one or more lithographic printing plates may thus be placed within the area defining the base portion of the box forming blank. The

retaining inserts may be placed over the article and fixed to the base portion towards the fold lines defining the base portion. The retaining insert ensures that the article cannot move within the box.

An advantage of the present invention is that both the box forming blank and the retaining insert may be made of cardboard. As such the process of packing and forming the box is more easily automated, and in addition the box is recyclable. A further problem is that the process of assembling and packing the box is not. easily automated.

The box according to the present invention is particularly applicable to transport or storage of fragile articles which are relatively thin in cross section and have a substantially square or rectangular shape.

Preferably the retaining insert is substantially cross shaped having a central portion and two pairs of oppositely disposed flaps extending from the central portion. One or more lithographic printing plates to be packed in the box may be placed substantially centrally on the box forming blank, within the base portion, which base portion is preferably shaped to be larger than the shape of the plate. The retaining portion may then be placed over the plate and attached to the base portion of the blank by means of adhesive applied to the flaps of the retaining insert _*

Preferably, each of the flaps of the retaining insert comprises two parallel folds extending parallel to the extreme edge of each flap, which folds are positioned to correspond with the thickness of the plates being packed in the box. These folds may be pre-formed or may be formed during the process of attaching the retaining inserts to the blank when the plates are in place.

Alternatively, the retaining insert comprises a bottom layer

and a top layer. The article to be packed is positionable o the bottom layer, and the top layer is then positionable ove the article and attachable to the bottom layer along the edge of each layer. The two layers may be attached together by an convenient means for example by means of adhesive, bu preferably they are attached together by means of a threa which is sewn around the edges of the layers thus completel enclosing the object within the layers.

The bottom layer of the insert may then be attached to the bas portion of the box forming blank by any convenient means, b for example means of adhesive.

The advantage of forming the retaining insert from a doubl layer in this manner, adds further protection to the object, and also reduces problems due to delamination of the cardboar used for the different components forming the box.

The fact that the base portion of the blank is substantiall larger in shape than the plates being packed, results in space or crush zone existing at each corner of the bas portion. This means that should the box be dropped, eac corner of the box may be substantially crushed before th plates within the box are damaged.

Advantageously, each of the flaps of the box forming blan comprises a second fold line parallel to the first fold line, and spaced apart from the fold line to define the thickness o the complete box. The second fold lines may be pre-formed o formed during the process of assembling the box.

Advantageously the first pair of flaps of the blank are deeper, and thus extend further out from the central portion than th second pair of flaps. The depth of each of the second pair o flaps will thus form a side wall of the finished box, whereas the first pair of flaps is sufficient to form a side wall, an also to extent to form a portion of a top surface of the box.

Each of the blank flaps thus comprises a portion defined between the two parallel fold lines which portion defines the thickness of the side walls of the box, and an edge portion extending from the second fold line to the edge of the flap. In use, when the plate or plates have been positioned on the central portion of the blank, and the retaining insert has been adhesively attached to the surface of the base portion, the two second flaps of the blank are positioned to define the thickness of the side walls, and the edge portions of each flap are folded over. Similarly, a first of the first pair of flaps is folded such that the edge portion extends over the two edge portions of the second pair of flaps. The edge portion of this first flap of a first pair of flaps may be attached to the edge portions of each of the second pair of flaps. Finally, the remaining flap of the first pair of flaps may be folded over and attached to all three of the other flaps. This final flap forms the opening flap, and in use is separated from the remainder of the box in order to gain access to the box.

Preferably, the retaining insert comprises a drawstring extending substantially parallel to the fold lines of the opening flap of the blank. In use, when the opening flap of the blank is released from the remains of the box in order to allow access into the box, the drawstring is used to detach one of the flaps of the retaining insert from the remainder of the retaining insert. It is then possible to remove the plates from within the retaining insert.

An advantage of the box according to the present invention is that although the opening lap is detached from the remains of the box, and one of the flaps of the retaining insert is detached from the rest of the retaining insert, the remainder of the box remains intact, and can be used to store the plates after delivery.

Preferably, the retaining means is attached to the blank by means of hot melt adhesive.

By means of the box according to the present invention, a range of different sizes and/or numbers of plates may be accommodated in a particular size of box.

In addition, the box forming blank may be made in a number of different sizes, with the retaining insert made in a corresponding number of compatible sizes. This further increases the range of different sizes and numbers of plates which may be packed in a box according to the present invention.

Embodiments of the invention will now be further described by way of example only with reference to the accompanying drawings in which:

Figure 1 is a plan view of a box according to a first embodiment the present invention in its unassembled state;

Figures 2, 3a and 3b are schematic representations showing the crush zone created by the box according to Figure 1;

Figures 4a and 4b are schematic representations showing a box construction used in a second embodiment of the invention;

Figures 5a and 5b are a schematic representation showing a box construction used in another preferred embodiment of the invention;

Figure 6 is a plan view of a box according to the present invention in its assembled state;

Figure 7 is a schematic representation showing a cross section of the closed box according to the present invention; and

Figures 8 to 12 illustrate a third embodiment of the invention comprising a double layer retaining insert.

Referring to Figure l, a box according to the present invention is designated generally by the reference numeral 10. The box 10 comprises a box forming blank 11. The box forming blank comprises a base portion 12 which is defined by top and bottom fold lines 13, 14 and side folds 15, 16. The blank 11 further comprises a first pair of side flaps 17, 18 and a second pair

of side flaps 19, 20. In this example, the base portion 12 has a generally rectangular shape and side flaps 17, 18 extend along the long lengths of the base portion 12, whereas side flaps 19, 20 extend along the short length of the base portion 12. Each side flap 17, 18, 19, 20 comprises a second fold line 21, 22, 23, 24 each of which extend substantially parallel to the first fold line 15, 16, 17, 18 respectively. The distance between the two fold lines defines the thickness of the box when assembled. In this example, each side flap comprises a further pair of fold lines 25, 26 extending substantially parallel to the fold lines 15, 16. These fold lines are used to add strength to the box as will be described later. The box

10 further comprises a retaining insert 27 which is generally cross shaped comprising a central portion 28 and flaps 29, 30, 31, 32.

In use one or more lithographic printing plates 33 are positioned substantially centrally within the base portion 12 of the blank 11. Typically, the box will be used to hold a pack of plates, containing a plurality of lithographic printing plates. Generally, the fold lines 15, 16, 25, 26 in the blank

11 are pre-formed, although they may be formed during the course of the assembly of the box.

The retaining insert 28 is then placed over the plates 33. The size of the insert 28 is chosen to correspond with the size of the base portion 12. Hot melt glue is applied to the base portion 12 in a position corresponding to the position of the flaps 29, 30, 31, 32 of the insert 28. The flaps 29 to 32 are then pressed down to adhere to the base portion 12. During the pressing process, fold lines 35, 36 are formed which define the thickness of the plates 33. Alternatively, the fold lines 35, 36 could be pre-formed. To assemble the box, side flaps 19, 20 are first of all folded into position as will be described in more detail later. The flap 18 is then folded over the two flaps 19, 20, and finally flap 17 is folded over all three flaps. Flap 17 may be secured to the remaining flaps by means

of an adhesive tape (see Figure 6) . To remove the plates 33 from the box once they have reached their final destination, flap 17 is detached from the remains of the box to allow access to the inside of the box. The flap 29 of insert 28 comprises a drawstring 37. The drawstring is be positioned towards the opening flap 17 of the blank 11. By pulling the drawstring, flap 29 becomes separated from the remainder of the retaining insert 28 which enables the plates to be removed. However, the remainder of the box remains intact and thus allows the plates to be stored in the box. The blank 11 and the insert 28 are made of laminated cardboard, and the flute direction of the cardboard is orientated such that the drawstring 37 runs parallel to the flute direction. This is to ensure that the drawstring may be easily operated.

Referring to Figure 2, a detail of a corner of the box 10 is shown in more detail. As can be seen, a base portion 12 is substantially larger than the size of the plates being held in the box. This creates a crush zone which effectively means that if the box is dropped on a corner, the box can crush without damaging a plate. Figures 2, 3 and 3b also show that different product size may be retained within a standard size of blank 11 and insert 28. The maximum size of the product must still allow reasonable space between the product and the corner of the box, whilst the minimum product size is such that a corner of the product extends beyond the insert 28.

Referring to Figures 4a and 4b, a preferred box construction is shown. The Figures 4a and 4b illustrate the purpose of the fold lines 25, 26 on flaps 19, 20 of Figure 1. As can be seen from the figures, fold lines (15, 23; 16, 24) define the thickness of the box. The side flaps 19, 20 are then further folded along fold lines 25, 26 in such a way that strength is added to the box.

Referring to Figures 5a and 5b, an alternative arrangement is shown. In this arrangement, the fold lines 25, 26 are not

present, and the side flap is only folded along lines 15, 16 and then attached to insert 28 by means of a hot melt adhesive at point 50.

Referring to Figure 6, an assembled box according to the invention is shown. As can be seen, although the individual side flaps are attached to each other by means of hot melt adhesive, once flap 17 has been positioned over the remaining flaps, an adhesive tape is positioned over the join to secure the box. In addition, polypropylene strapping 62, 63 is strapped around the box to further add strength and also to aid handling of the box.

Referring to Figure 7, it can be seen that the side walls of the box are vertical which facilitates ink jet printing, bar coding etc for "on shelf" identification.

Referring to Figures 8 to 12 a double layer retaining insert is shown and is designated generally by the reference numeral 80. The retaining insert 80 comprises a base layer 81 and a top layer 82. In use the product which is to be packaged is placed centrally on the base layer 81 and the second layer 82 is then positioned over the product and attached to the base layer 81. The two layers 81, 82 may be attached to each other by any convenient means, but in this example they are attached together by means of sewing a chain stitch around the edge of the two layers.

Once the retaining insert 80 has been assembled in this way, it is then positioned on the base portion 110 of the box forming blank 120. The retaining insert 81 may be attached to the base portion by any inconvenient means for example adhesive. The box forming blank 120 is then assembled in a similar manner to that described above with reference to figures 1 to 7.

Although the present invention has been described in terms of a box for holding one or more lithographic printing plates, and

particularly to a box for holding one or more packs ea holding a plurality of lithographic printing plates, it is be understood that the invention relates to a box for holdi any object or objects particularly fragile objects a particularly objects which are flat. For example, painting records, panes of glass etc.