PALLET

Abstract: A flat blank (1) of material, is formed of corrugated cardboard or plastics material. The blank (1) forms, when assembled, a structural element including a number of wall forming panels (2, 3, 4, 5) delimited by a set of transverse fold-lines and having at least two flaps (6, 7) which provide a diagonal cross-brace. The structural element may be formed as a separate component or as an integral part of a larger structure such as a pallet or box.

Description: PALLET The present invention relates to a structural member, particularly although not exclusively for use in packaging. Conventionally, goods have been stored and/or transported on pallets which have usually been of timber construction. Timber is a disadvantageous material for pallets as it is heavy, splinters and is likely to fracture when dropped, particularly when allowed to fall so that a corner of the pallet impacts the ground first. There have therefore been many attempts to provide a pallet and/or palletised container, tray, or the like which overcomes these disadvantages. More recently, increased environmental awareness and the desire to promote re-cycling has brought forward a number of proposals for cardboard pallets. For example, British Patent Specification No. 1 519 741 (ASHTON) describes a rectangular box which is formed of a blank of stiff material and includes four side walls supporting pairs of opposing bottom closure flaps which overlap one another and are provided with tubular bearers which are spaced apart and extend across the bottom of the box, the bearers being formed by a second folded blank of stiff material . This box has the disadvantage that the bearers are not integrated with the box thereby weakening the overall structure. That is, the bearers must be assembled separately and then fitted to the box. Disadvantageously, the weight of the box is supported by the relatively thin bottom wall of the box when it is lifted by the tines of a forklift truck rendering it unsuitable for heavy loads in particular; moreover the bottom of the box and its contents are easily damaged if the tines are advanced at too high a level. It is an object of the present invention to provide an improved structural member for use in packaging which is also strong, stiff, resistant to impact, simple to assemble and disassemble, easily stored and biodegradable. The member may be formed as a separate element for use individually or within another structure such as, for example, furniture, or as an integral part of a larger structure such as a box, a pallet or the like. It is a further object of the present invention to provide an improved structural member which is suitable for fabrication from not only corrugated fibreboard but other suitable materials including, but not limited to, sheet plastics materials and composites. According to one aspect of the present invention there is provided a structural member for use in packaging including a plurality of wall forming panels delimited by a set of transverse fold-lines and having at least two flaps extending from a common fold-line, at least one of said flaps including a further fold-line, wherein the flaps are sized such that their free ends abut selected ones of said transverse fold-lines thereby providing a diagonally- braced structural member. According to a further aspect of the present invention there is provided a blank for forming a structural member which blank includes a portion of stiff material foldable at a plurality of lines of weakness made therein to form a beam having at least four walls and at least two flaps extending from a common fold-line, at least one of said flaps including a further fold-line, wherein the flaps are foldable so that their free ends abut selected ones of said transverse fold-lines thereby providing a diagonally-braced structural member. According to a still further aspect of the present invention, there is provided a method of forming a structural member for use in packaging which includes the steps of forming a pair of flaps in a blank, one of said flaps being formed with a fold line and subsequently arranging said flaps to provide diagonally opposed cross- bracing of a beam formed by folding said blank about a further set of fold-lines. It will be apparent that the member may be formed with four or more sides of single or more thickness and that any suitable material may be utilised which has the requisite stiffness yet which is capable of being folded to form the braced member. In particular, a plastics material may be used. Such a material might allows sterilisation of the entire member to facilitate use in a sterile environment. Equally, the high strength to weight ratio is advantageous for air-freight packaging applications. The member may be incorporated in numerous forms of packaging, including, but not limited to, pallets and palletised containers of the two-way and four-way entry type. The member may also be formed as an inexpensive separate component for use in other non-packaging applications where its high strength to weight ratio and stiffness provides many benefits. In order to aid in understanding the invention some specific embodiments thereof will now be described by way of example and with reference to the accompanying drawings, in which: Figure 1 is a plan view of a flat blank for a structural element according to the invention; Figures 2a to 2d are side views of the blank of Figure 1 showing steps in the formation of the structural element; Figure 3 is a plan view of a variant of the structural element of Figure 1 having double thickness walls; Figure 4 is an oblique parallel view of the assembled element of Figure 3; Figure 5 is a plan view of a flat blank for a four-way entry pallet incorporating the structural element of Figure 4; Figure 6 is a plan view of a blank for a reinforcing base of the pallet of Figure 5; Figure 7 is an oblique parallel view of the assembled pallet of Figure 5; and Figure 8 is a plan view of a flat blank for a box incorporating the structural element of Figure 4. Referring to Figures 1 and 2, there is shown a flat blank 1 of material, suitably corrugated cardboard, although alternatively a plastics or composite material may be employed. The corrugations or flutes are arranged to run perpendicular to transverse fold lines C to G shown in broken line on the Figure. The blank 1 has four wall panels 2,3,4,5 and a pair of flaps 6,7 which, when assembled, form a structural element or rectangular cross-section beam 8, as shown in the sequence of views of Figure 2. As is clear from the Figures, the flaps 6,7 extend from a common fold-line D, the larger flap 7 being subdivided by fold C into two portions 7a, 7b. The fold line C is necessary to provide opposing diagonal cross-bracing to that provided by the smaller flap 6. Once assembled the beam 8 is prevented from unravelling by adhesive, clip or staple means. Alternatively, rather than using an adhesive it has been found convenient, particularly where the application requires re-use, to place a layer of non-slip sheet material (not shown) on the flat blank which sheet is then sandwiched between the facing surfaces of the blank as it is formed into the structural element. It then being necessary only to either clip, tape or otherwise secure the element to form a strong and resilient structure. Such an approach is particularly useful where the element is formed with double or more thickness walls as is described in more detail below. Figure 3, shows a variant of the blank of Figure 1, in which additional diagonal cross-bracing is provided to the beam 9 by a third flap 10. The beam 9 is further reinforced by having an additional thickness added to each wall of the beam 9 by panels 11, 12, 13 and 14. A structural element as described above may be incorporated in any form of palletised packaging e.g. palletised tray, pallet, pallet box or the like. Thus with reference to the remaining Figures, a four-way entry pallet 26 may be formed from blanks 15,16. The main blank 15 has integral leg-forming structural elements 17a-c of the double-wall dual-flap type. A pair of tongues 18a, 18b are each attached via parallel fold-lines 19a, 19b to opposite sides of a base panel 19. The separate blank 16 has a floor panel 20 to which is attached, again via parallel fold-lines 21a, 21b, a pair of panels 22a, 22b. A rectangular keying panel 23 is adhesively or otherwise suitably secured to the upper surface of the blank. The pallet 26 is assembled by first securing the separate blank 16 to the main blank 15 so that the floor panel 20 overlies the base 19. The panels 22a, 22b are then folded around the ends of the base 19 and secured to its underside. It will be noted that the panels 22a, 22b do not extend completely underneath the base 19, instead the tongues 18a, 18b are folded and secured underneath the base 19; consequently a rigid, strong pallet platform 24 is formed. The next stage is for the structural elements 17a-d to be folded in the manner described above with reference to Figure 1 to form legs 25 at each corner of the pallet 26. Finally, the keying panel 23 allows a sleeve (not shown) to be positioned on top of the platform 24, if required. A further example of the use of the structural element in packaging is shown in Figure 8, where there is illustrated a blank 28 for a box which includes the structural element described above in relation to Figure 3. The blank includes not only a set of four side walls 29a,29b, 29c,29d but also a set of four top flaps 30a, 30b, 30c, 30d. Such a box is particularly suitable for manufacture from a plastics material. It will be appreciated by those skilled in the art that the structural element described above has applications not only within the packaging field but also in other areas such as furniture, where a rigid lightweight and strong beam is required. Although the above embodiments describe a rectangular cross-section beam, it will be apparent that other forms of polygonal cross- section are possible where the included angle between adjacent wall forming panels will be less than 90° . Furthermore, the structural element may be formed as individual pads or beams for providing support to existing containers and articles.

Claims: Claims ; 1. A structural member for use in packaging including a plurality of wall forming panels delimited by a set of transverse fold-lines and having at least two flaps extending from a common fold-line, at least one of said flaps including a further fold-line, wherein the flaps are sized such that their free ends abut selected ones of said transverse fold-lines thereby providing a diagonally-braced structural member. 2. A member as claimed in Claim 1 , having a polygonal cross-section. 3. A member as claimed in Claim 2 , wherein the cross- section is rectangular. 4. A member as claimed in any preceding Claim, wherein there are sufficient wall forming panels to provide a multi-layer wall. 5. A member as claimed in any preceding Claim, formed from a corrugated material. 6. A member as claimed in Claim 5 , wherein the corrugations are perpendicular to the transverse fold lines. 7. A member as claimed in any preceding Claim, formed from a plastics material . 8. A member as claimed in any preceding Claim, wherein a sheet of non-slip material is provided between facing surfaces of the wall forming panels. 9. A blank for forming a structural member as claimed in Claims 1 to 8, includes a portion of stiff material foldable at a plurality of lines of weakness made therein to form a beam having at least four walls and at least two flaps extending from a common fold-line, at least one of said flaps including a further fold- line, wherein the flaps are foldable so that their free ends abut selected ones of said transverse fold- lines thereby providing a diagonally-braced structural member. 10. A method of forming a structural member as claimed in Claims 1 to 8, includes the steps of forming a pair of flaps in a blank, one of said flaps being formed with a fold line and subsequently arranging said flaps to provide diagonally opposed cross-bracing of a beam formed by folding said blank about a further set of fold-lines.

Inventors: JOHNSON BRIAN PATRICK, JOHNSON, BRIAN, PATRICK
Applicants: JOHNSON BRIAN PATRICK, JOHNSON, BRIAN, PATRICK
Application year: 1998
Main classification: B65D19
IPC codes: B65D19