BOX WITH INTEGRAL CORNER REINFORCEMENTS

Abstract: A method of making a box having a reinforced corner comprising folding the box (10) from a prescored sheet of material so as to leave a flap (26) adjacent each corner. The flap (26) is prescored (28) and is pushed towards its hinged corner whereby it buckles into an approximately cylindrical shape. The end of the flap is secured by glueing or stapling so as to stabilise the cylindrical shape. The cylinder considerably increases the stiffness and crush resistance of the whole box and may allow many more boxes to be stacked.

Description: BOX WITH INTEGRAL CORNER REINFORCEMENTS This invention relates to boxes especially for the transport of food and in particular relates to a method of reinforcing the corners of such boxes. Boxes for the transport of food such as fresh vegetables and fruits often comprise relatively shallow rectangular box portions having raised opposite end portions. Figure 5 of the accompanying drawings illustrates one such general design. The raised end portions allow several boxes to be stacked one on top of the other without damage to the contents while access of air and the ability for visual inspection are not impaired with presentation being improve . Many boxes of this type are produced from wood, but this material is not currently favoured for a number of reasons. Boxes of this type may also be produced from cardboard, a material whose strength is limited, and thus the height to which a stack of boxes can be made is limited if the lower¬ most boxes are not to be crushed. The invention seeks to provide a method of reinforcing boxes which reduces or overcomes the above problem. According to the present invention there is provided a method of making a box having a reinforced corner which comprises folding the box from a prescored sheet of material characterised in that adjacent each corner a flap of scored material is present which is deformed into an SUB STI TUTESHEET approximately cylindrical shape and secured whereby to provide reinforcement for the corner. The invention will be described further, by way of example, with reference to the accompanying drawings, in which : Figures 1 to 4 illustrate the production of the reinforced corner; Figure 5 is a diagramatic general perspective view of a suitable form of box; Figure 6 is a view of a blank from which the box of figure 5 may be made; and Figure 7 is a detail of one corner of the box of figure 5. Referring to the drawings, Figure 5 illustrates a form of box often used for the transport of food, for example cauliflowers or peaches. The box, generally designated 10, comprises a base 12 generally rectangular in shape having longitudinal sides 14 and transverse ends 16. As illustrated the sides 14 are not as high as the ends 16 but this a matter of choice, since the sides 14 can be made to be as high as the ends 16. The shape illustrated allows air freely to circulate even when boxes are stacked. As can be seen from figure 5 the ends 16 have overlapping top 18 and side 20 portions and the portions 20 are affixed to the sides 14 for example at sealing points 22. The "platforms" formed by the top portions 18 enable boxes to be stacked one on top of the other without damage to the contents. The box 5 may be produced from a creased and cut blank 24 SUBSTITUTESHEET as illustrated in figure 6. As can be seen from figure 6 and 7 the blank has portions 26 which are in part supernumerary in that the box could still be formed if these portions were not there. In accordance with the invention these portions 26 are formed (as can be seen better from figures la and lb) with a plurality of vertical score or crease lines 28 together with an uncreased portion 30. Once the box has been formed to the stage illustrated in figure 7, a pushing device 32 contacts the plain portion 30 of the flap 26 and pushes it to the left as illustrated in figures 1 to 4 causing it to buckle progressively until it reaches the cylindrical shape illustrated in figure 4. At this point the plain portions 30, the flaps 20 and the sides 14 may be affixed e.g. glued, stapled or the like, to the remainder of the box therby stabilising the cylinder and securing the box, preferably in one operation. As can be seen from figure 4 the cylinder need not be geometrically exact in order to perform its function. The nett result is that each corner of the box is reinforced by the presence of the cylindrically folded flap 26 without using any additional material increasing the weight of the box since the flap 26 is produced from the same blank 24 which made the box as illustrated in figure 5. However, in use, the presence of the cylinder considerably increases the stiffness and crush resistance of the whole box and may allow many more boxes of produce to be stacked than was hitherto the case with boxes of the same material. The method of the invention may be carried out on boxes SUB S TITUTE SHEET made from most materials which can be creased and folded, for example cardboard, plastics material, and the like. However plastics materials are preferred for their generally superior strength, and the ability to employ ultra-sonic welding techniques which can be advantageous in terms of processing. The cylinder, being formed from the flap 26 whose width is the same as the height of the box side 14, has a diameter dependant on the side height. Thus, where the height of the side is relatively small the cylinder will have a lower diameter and therefore a greater curveture. In these circumstaces, corrugated cardboard may not have sufficient burst strength to be satisfactorily employed, whereas plastics materials, e.g. polyolefins, may be scored sufficiently densely (e.g. 5mm intervals) to form the cylinder without bursting. Where the box height is greater the cylinder is of correspondingly larger diameter and, for instance, corrugate cardboard could be employed. The invention further includes a box having reinforced corners comprising cylindrically folded flaps. SUBSTITUTESHEET

Claims: CLAIMS 1. A method of making a box having a reinforced corner which comprises folding the box from a pre-scored sheet of material characterised in that adjacent each corner a flap of scored material is present which is deformed into an approximately cylindrical shape and secured whereby to provide reinforcement for the corner. 2. A method as claimed in claim 1 in which the flap of scored material is pushed inwardly towards its hinged corner whereby it deforms into an approximately cylindrical shape after which it is secured by glueing, stapling or the like. 3. A method as claimed in either of claims 1 or 2 in which each corner of the box is reinforced by the presence of a cylindrically folded flap 4. A method as claimed in any of claims 1 to 3 carried out on boxes made from materials which can be creased and folded, including cardboard, plastics material, and the like. 5. A method as claimed in claim 4 in which the boxes are formed from plastics materials such as polyolefins. SUBSTITUTE SHEET 6. A method as claimed in any of claims 1 to 5 in which the scoring is carried out at density of approximate 5mm intervals. 7. A method as claimed in any of claims 1 to 6 in which the cylinder is formed from a flap of material which otherwise would not contribute to the formation of the box. SUBSTITUTESHEET

Inventors: MACKINNON ROBIN, MACKINNON, ROBIN
Applicants: FRA MO SNC, FRA.MO. SNC DI FRANCA RIVA & C.
Application year: 1991
Main classification: B65D5
IPC codes: B65D5