Large numbers of pallets are used each year for materials handling in industry.

The vast majority of these pallets are made from timber. In this case, the pallets are either single decked, i. e consist of a single load carrying platform supported on legs, or double decked, i. e consist of a load carrying platform separated from a lower deck by suitable spacers. The pallets are generally of slatted configuration and generally have nine legs or nine timber blocks separating the load carrying platform and the lower deck. These legs or spacers are generally comprised of timber, being between 100 mm and 150 mm square, with a height of 100 mm, providing to the pallet fork entry which is either two way or four way.

These wooden pallets have been satisfactorily used for at least a century or more. However, they have a number of disadvantages in that they tend to splinter, they are assembled with nails, they are difficult to dispose of, and because they do not nest they are difficult to return. They also absorb water and are subject to fungal attack.

Pallets have been made from materials other than wood, such as for example wood fibre compressed into suitable shapes, or from plastics materials.

Examples of such pallets are disclosed in US Patents Nos 2 501 506 to George, 3 092 046 to Davidson, 3 661 099 to Shelor, 4 378 743 to McFarland and 5 584 951 to McFarland.

There is a need for a new type of pallet.

SUMMARY OF THE INVENTION According to the invention there is provided a pallet comprising a load carrying platform having an upper surface and a lower surface formed from a rigid corrugated sheet, a plurality of regularly spaced apertures arranged in rows through the load carrying platform, and a leg element associated with each aperture, each leg element comprising a hollow U-or V-shaped leg having an open mouth and flanges extending on either side of the open mouth of the leg, each flange being corrugated to correspond to the corrugations of the load carrying platform, each leg element being attached to the load carrying platform with the leg in register with one of the apertures and with the flanges on adjacent leg elements associated with a row of apertures abutting each other to form beams running transverse to the corrugations of the load carrying platform.

Each leg element may be attached to the lower surface of the load carrying platform. Alternatively, each leg element may be attached to the upper surface of the load carrying platform with the leg protruding through its associated aperture.

The load carrying platform preferably includes three sets of three apertures each, one set located at each end of the load carrying platform and the third set located in the middle of the load carrying platform. In this case, when the leg elements are attached to the load carrying platform, there are formed three beams running transverse to the corrugations.

The pallets of the invention are preferably nestable, with the legs of a first pallet nesting in the legs of a second pallet, and so on.

As indicated, the load carrying platform is formed from a rigid corrugated sheet.

In the rigid corrugated sheet, the corrugations preferably have a pitch of from 10 mm to 50 mm inclusive, more preferably from 15 mm to 30 mm inclusive, and a distance between the centres of two adjacent corrugations of from 30 mm to 150 mm inclusive, more preferably from 50 mm to 100 mm inclusive.

Further, the rigid corrugated sheet preferably has a thickness of from 2 mm to 6 mm inclusive, and a density of from 900 kg/m3 to 1600 kg/m3 inclusive, more preferably from 1200 kg/m3 to 1400 kg/m3 inclusive.

The pallet may include a lower deck releasably attached to the legs of the leg elements, the lower deck also preferably being formed from a rigid corrugated sheet.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a plan view of a first pallet of the invention; Figure 2 is a side view of the pallet of Figure 1 along the arrow A; Figure 3 is an enlarged view of the circled section of Figure 2; Figure 4 is a side view of the pallet of Figure 1 along the arrow B; Figure 5 is a side view of a second pallet of the invention; Figure 6 is a schematic view of the stacking of several pallets of the invention; and Figure 7 is a schematic view of a rigid corrugated sheet from which the load carrying platform of the invention may be manufactured.

DESCRIPTION OF EMBODIMENTS The crux of the invention is a pallet comprising a load carrying platform supported on a plurality of leg elements. The load carrying platform has an upper surface and a lower surface and is formed from a rigid corrugated sheet.

The rigid corrugated sheet may be any suitable corrugated sheet. For example, the corrugated sheet may be formed from a plurality of sheets of paper impregnated with a suitable resin, which is set to form a rigid product.

Alternatively, the corrugated sheet may be made according to the method of PCT/GB 99/00792 (WO 99/48170). This patent application teaches a method of making a shaped component from a substantially dry resinated feedstock comprising a material selected from the group consisting of particles or fibres of a lignocellulosic material, particles of an exfoliated vermiculite and particles of an expanded perlite, which material has been resinated with a thermosetting resin, or a precursor thereof, the resin being in a latent condition, and optionally a hydraulic binder. The method includes the steps of placing the substantially dry resinated feedstock on a flexible carrier sheet; placing this product between the platens of a press and subjecting the product to suitable conditions of temperature and pressure to mould the product into a desired shape, in this case a corrugated shape, and to cause the resin to polymerise or to set; removing the product from the press; and optionally removing the flexible carrier sheet from the product to give the shaped component.

Further, the corrugated sheet may be made by the methods described in PCT/GB 98/01713 (WO 98/56991) and PCT/IB 01/02108 (WO 02/38676).

The pallet of the invention is preferably waterproof, allowing for resistance to rain wetting, and steam or scrub cleaning. In this case, the rigid corrugated sheet is preferably composed of a thermoplastics material or lignocellulosic fibres bound with a suitable resin, rather than paper. It is also preferred that the rigid corrugated sheet be made from a material which is capable of being recycled.

Referring to Figure 7, the line marked X indicates the pitch of a corrugated sheet, the line marked Y indicates the distance between the centres of adjacent corrugations of a corrugated sheet, and the space between the arrows marked Z indicates the thickness of the corrugated sheet.

The rigid corrugated sheet from which the load carrying platform of the pallet of the invention is made preferably has corrugations with a pitch of from 10 mm to 50 mm inclusive, more preferably from 15 mm to 30 mm inclusive, and a distance between the centres of two adjacent corrugations of from 30 mm to 150 mm inclusive, more preferably from 50 mm to 100 mm. Further, the rigid corrugated sheet preferably has a thickness of from 2 mm to 6 mm inclusive, and a density in the range of from 900 kg/m3 to 1600 kg/m3 inclusive, more preferably from 1200 kg/m3 to 1400 kg/m3 inclusive.

This is to be contrasted with conventional corrugated paper which generally, at its largest, has a pitch of 2.5 mm and a distance between centres of adjacent corrugations of about 6.5 mm, a thickness of approximately 100 microns and a density of from 500 kg/m3 to 800 kg/m3.

A plurality of regularly spaced apertures arranged in rows are formed through the load carrying platform in any suitable manner.

A leg element is then associated with each aperture. Each leg element comprises a hollow U-or V-shaped leg having an open mouth and flanges extending on either side of the open mouth of the leg, each flange being corrugated to correspond to the corrugations of the load carrying platform.

Each leg element is attached either to the lower surface of the load carrying platform with the leg in register with one of the apertures and with flanges on adjacent leg elements associated with a row of apertures abutting each other to form beams running transverse to the corrugations of load carrying platform, or is attached to the upper surface of the load carrying platform with the leg protruding through its associated aperture and with the flanges on adjacent leg elements associated with a row of apertures abutting each other to form beams running transverse to the corrugations of the load carrying platform.

Each leg element may be formed in the manner described above. The pitch of the leg of the leg section is the distance required between the load carrying platform and any surface on which the platform is to be placed, or, where the load carrying platform includes a lower deck, the distance between the load carrying platform and the lower deck.

The mouth of the leg of each leg section is preferably substantially the same size as each aperture in the load carrying platform.

Each leg element is attached to the lower surface or the upper surface of the load carrying platform, for example using a suitable adhesive, with the leg in register with one of the apertures and with the flanges on adjacent leg elements associated with a row of apertures abutting each other.

If desired, a lower deck may be included in the pallet. In this case, the lower deck, comprising a corrugated sheet, is releasably attached to the legs of the leg elements, for example with suitable removable clips.

The invention will now be described in more detail with reference to the accompanying drawings.

Referring to Figures 1 to 4 there is shown a pallet 10 consisting of a load carrying platform 12 having an upper surface 14 and a lower surface 16, and nine leg elements 18. It can be seen that the load carrying platform 12 is formed from a rigid corrugated sheet, such as that illustrated in Figure 7.

Nine apertures 20 are formed in the load carrying platform 12 in three rows each of three apertures.. Each leg element 18 is associated with one of these apertures 20.

Each leg element 18 consists of a hollow V-shaped leg 22 and two flanges 24 on either side of the open mouth 26 of the leg 22. Each flange 24 is corrugated to correspond to the corrugations of the load carrying platform 12.

In use, each leg element 18 is adhered to the lower surface 16 of the load carrying platform 12 with each leg 22 in register with one of the apertures 20 and with the flanges 24 on adjacent leg elements 18 abutting each other at points 28 to form beams running the width of the load carrying platform 12 and transverse to the corrugations of the load carrying platform. These beams provide support for the load carrying platform 12 in use.

As the mouth 26 of each leg 22 of each leg element 18 is substantially the same size as each aperture 20 and as the legs 22 are hollow, the pallets 10 may be nested when not in use. This is illustrated in Figure 6 where it can be seen that the legs 22 of a first pallet 10A fit through the apertures 20 in a second pallet 10B and so on so that the pallets 10A, 10B, 10C nest. Thus results is substantial space saving. For example a single deck wood pallet requires a vertical stacking space of 120 mm while a pallet of the invention of equivalent dimensions only requires a vertical stacking space of 12.9 mm, giving a nine fold space advantage.

In certain circumstances, it may be desirable for a pallet to have a lower deck, for example for rigidity and multi-stacking purposes. Thus, referring to Figure 5 there is shown a pallet 40 consisting of a load carrying platform 42 and leg elements 44, which are substantially the same as the load carrying platform 12 and leg elements 18 of Figure 1, together with a lower deck 46. The lower deck 46 is also formed from a corrugated sheet and is attached to the legs 48 of the leg elements 46, for example, using removable clips. When it is desired to store the pallets 40, the lower decks 44 may be unclipped from the legs 48 and the load carrying platforms 42 with associated leg elements 44 nested in the same manner as is illustrated in Figure 6. The lower decks 46 may also be stacked.

The main advantage of the pallet of the invention is that it is designed so that it can be stacked in a manner which occupies the minimum amount of space, thus ensuring that the pallets are easily returnable to their point of origin.

Other advantages of the pallet of the invention are that as it is not made of wood, it does not include nails and does not splinter, it has a lower weight relative to a wooden pallet, it is hygenic, it can be made at a lower cost and is recyclable.