DE69809075T2 - PALETTE - Google Patents

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

The invention relates to a structural element, particularly, although not exclusively, for use in packaging.

Traditionally, goods are stored and/or transported on pallets, which are usually constructed of wood. Wood is an unfavourable material for pallets, as it is heavy, splinters and breaks easily when dropped, especially if dropped in such a way that a corner of the pallet hits the ground first. Many attempts have therefore been made to create a pallet and/or palletisable container, magazine or the like which overcomes these disadvantages.

Recently, increasing environmental awareness and the desire to encourage recycling have led to a number of proposals for cardboard pallets. For example, British Patent Specification No. 1 519 741 (ASHTON) describes a rectangular box made from a blank of rigid material and containing four side walls carrying pairs of opposite lower closing flaps which overlap each other and which are provided with tubular supports which are spaced apart from each other and extend across the bottom of the box, the supports being made from a second folded blank of rigid material. This box has the disadvantage that the supports are not integrated into the box, thus weakening the entire structure. This means that the supports must be assembled separately and then attached to the box. Unfortunately, the weight of the box is supported by the relatively thin bottom wall of the box when lifted by the tines of a forklift truck, making it particularly unsuitable for heavy loads and, in addition, the bottom of the box and its contents are easily damaged if the tines are extended too high.

GB 620 701 A discloses a portable material handling pallet suitable for use in forklift operation and having tubular support members.

It is an object of the present invention to provide an improved structural element for use in packaging which is also strong, rigid, resistant to impact, easy to assemble and disassemble, easy to store and biodegradable. The element may be formed as a separate element for use alone or in another structure such as a piece of furniture or as an integral part of a larger structure such as a box, pallet or the like.

Another object of the present invention is to provide an improved structural element suitable for manufacture not only from corrugated fiberboard, but also from other suitable materials including, but not limited to, sheet plastics and composites.

According to one aspect of the present invention there is provided a structural element for use in packaging comprising a plurality of wall-forming panels defined by a set of substantially parallel transverse fold lines and having at least two tabs extending from a common one of the fold lines and at least one of the tabs including a further fold line, the tabs being sized so that their free ends abut different selected ones of the transverse fold lines to form a diagonally braced structural element.

According to another aspect of the present invention, there is provided a blank for manufacturing a structural member including a section of rigid material that can be folded along a plurality of substantially parallel lines of lower strength formed therein to produce a beam having at least four walls and at least two tabs extending from a common one of the lines of lower strength, at least one of the tabs including another line of lower strength, the tabs abutting different, selected ones of the transverse fold lines to form a diagonally braced structural member.

According to a further aspect of the present invention, there is provided a method of manufacturing a structural element comprising the steps of forming a A method of manufacturing a blank comprising forming a pair of tabs in a blank, one of the tabs being provided with a fold line, and then arranging the tabs to form diagonally opposed cross bracing of a beam made by folding the blank about a further set of substantially parallel cross fold lines so that their free ends abut against different selected ones of the cross fold lines.

It will be appreciated that the element may be provided with four or more sides of one or more thicknesses and that any suitable material may be used which has the required rigidity but which can be folded to form the braced element. In particular, a plastic material may be used. Such a material may allow sterilization of the entire element to enable use in a sterile environment. Likewise, the high strength to weight ratio is advantageous for use in air cargo packaging.

The element can be incorporated into a wide range of forms of packaging, including but not limited to pallets and palletised containers of the two-way and four-way entry type. The element can also be designed as a low-cost separate component for use in non-packaging applications, where its high strength-to-weight ratio and rigidity provide many advantages.

In order to facilitate the understanding of the invention, some specific embodiments thereof are described below by way of example and with reference to the accompanying designations, 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 in Figure 1 showing steps in the formation of the structural element;

Fig. 3 is a plan view of a variant of the structural element in Fig. 1 with double thick walls;

Fig. 4 is an oblique parallel view of the composite element in Fig. 3;

Fig. 5 is a plan view of a flat blank for a four-way entry pallet incorporating the structural element in Fig. 4;

Fig. 6 is a plan view of a blank for a reinforcing base of the pallet in Fig. 5;

Fig. 7 is an oblique parallel view of the assembled pallet in Fig. 5 ; and

Fig. 8 is a plan view of a flat blank for a box incorporating the structural element in Fig. 4.

In Fig. 1 and 2 there is shown a flat blank 1 made of material, suitably corrugated cardboard, although a plastic or composite material may be used. The flutes are arranged so as to run perpendicular to transverse fold lines C to 6 which are shown in the figure with dashed lines.

The blank 1 comprises four wall panels 2, 3, 4, 5 and a pair of tabs 6, 7 which, when assembled, form a structural member or beam 8 of rectangular cross-section as shown in the sequence of views in Fig. 2. The tabs 6, 7 extend, as can be seen from the figures, from a common fold line D, the larger tab 7 being divided into two sections 7a, 7b by fold C. The fold line C is necessary to provide diagonal cross bracing opposite that provided by the smaller tab 6. When the beam 8 is assembled, adhesive, clamping or stapling means are used to prevent it from coming apart. As an alternative to using an adhesive, it has been found practical, particularly where the application requires reuse, to use a layer of non-slip sheet material (not shown) onto the flat blank, the film then being trapped between the facing surfaces of the blank as it is formed into the structural element. It is then only necessary to clamp, tape or otherwise secure the element to form a strong and resilient structure. This procedure is particularly useful when the element is provided with walls of double or greater thickness, as described in more detail below.

Fig. 3 shows a variant of the blank in Fig. 1, in which the beam 9 is provided with additional diagonal cross bracing by a third tab 10. The beam 9 is further reinforced as each wall of the beam 9 is given additional thickness by plates 11, 12, 13 and 14.

A structural element as described above can be incorporated into any form of palletized packaging, such as a palletized magazine, pallet, pallet box or the like. Thus, as can be seen with reference to the remaining figures, a four-way entry pallet 26 can be formed from blanks 15, 16. The main blank 15 has integral foot-forming structural elements 17a-c of the double-wall, double-tab type. A pair of tongues 18a, 18b are each attached via four parallel fold lines 19a, 19b to opposite sides of a base plate 19. The separate blank 16 has a bottom plate 20 to which a pair of plates 22a, 22b are attached, again via parallel fold lines 21a, 21b. A rectangular keying panel 23 is glued or otherwise suitably secured to the top of the blank.

The pallet 26 is assembled by first attaching the separate blank 16 to the main blank 15 so that the bottom plate 20 overlies the base 19. The plates 22a, 22b are then folded around the ends of the base 19 and attached to its underside. It can be seen that the plates 22a, 22b do not extend completely under the base 19, but instead the tongues 18a, 18b are folded under the base 19 and attached thereto so that a rigid, solid pallet platform 24 is formed.

The next step is for the structural elements 17a-d to be folded in the manner described above with reference to Fig. 1. Finally, the end plate 23 allows a cover (not shown) to be attached to the top of the platform 24 if required.

Another example of the use of the structural element in packaging is shown in Fig. 8, which shows a blank 28 for a box containing the structural element described above in connection with Fig. 3. The blank contains not only a set of four side walls 29a, 29b, 29c, 29d, but also a set of four upper flaps 30a, 30b, 30c, 30d. Such a box is particularly suitable for manufacture from a plastics material.

It is obvious to those skilled in the art that the structural element described above can be used not only in the field of packaging, but also in other fields, for example for furniture, when a rigid, light and strong support is required. Although the embodiments described above describe a support with a rectangular cross-section, it is obvious that other shapes with a polygonal cross-section are possible if the included angle between adjacent wall-forming panels is less than 90º. Furthermore, the structural element can be designed as individual supports or beams that support existing containers or objects.

Claims (10)

1. Structural element for use in packaging, comprising a plurality of wall-forming panels (2, 3, 4, 5) delimited by a group of substantially parallel transverse fold lines (D to G) and having at least two tabs (6, 7, 10) extending from a common one of the fold lines (D to G), and at least one of the tabs (6, 7, 10) containing a further fold line (C), the tabs (6, 7, 10) being dimensioned such that their free ends abut different, selected ones of the transverse fold lines (D to G), so that a diagonally braced structural element is formed. 2. Element according to claim 1, which has a polygonal cross-section. 3. Element according to claim 2, wherein the cross section is rectangular. 4. Element according to one of the preceding claims, wherein there are sufficient wall-forming panels (2, 3, 4, 5) to form a multi-layer wall. 5. An element according to any preceding claim, which consists of a corrugated material. 6. Element according to claim 5, wherein the corrugations are perpendicular to the transverse fold lines (C to G). 7. Element according to one of the preceding claims, which consists of a plastics material. 8. Element according to one of the preceding claims, wherein a layer of non-slip material is present between mutually facing surfaces of the wall-forming panels (2, 3, 4, 5). 9. A blank (1) for producing a structural element according to claims 1 to 8, comprising a section of rigid material which can be folded along a plurality of substantially parallel lines of lower strength (D to G) formed therein to produce a beam (8) having at least four walls (2, 3, 4, 5) and at least two tabs (6, 7, 10) extending from a common one of the lines of lower strength (D to G), at least one of the tabs (6, 7, 10) including a further line of lower strength (C) and the tabs (6, 7, 10) abutting different selected ones of the transverse fold lines (D to G) to form a diagonally braced structural element. 10. A method of manufacturing a structural element according to claims 1 to 8, including the steps of forming a pair of tabs (6, 7, 10) in a blank (1), one of the tabs (6, 7, 10) being provided with a fold line (C), and then arranging the tabs (6, 7, 10) to form diagonally opposed cross bracing of a beam (8) which is manufactured by folding the blank (1) around a further set of substantially parallel cross fold lines (D to G) so that their free ends abut against different, selected ones of the cross fold lines (D to G).