GB2213462A

GB2213462A - Pallets

Info

Publication number: GB2213462A
Application number: GB8900244A
Authority: GB
Inventors: Dennis William Green; Michael John Coles
Original assignee: Dufaylite Developments Ltd
Current assignee: Dufaylite Developments Ltd
Priority date: 1988-01-07
Filing date: 1989-01-06
Publication date: 1989-08-16
Also published as: GB8800330D0; GB8900244D0

Abstract

An inexpensive pallet construction is described, in its simplest form consisting merely of two face sheets 2, e.g. of corrugated cardboard, and having an open structure, e.g. a paper or card honeycomb 3, between them. The open structure can be penetrated sideways by the prongs of a fork-lift truck to pick up a loaded pallet, the pallet being sufficiently strong (although lightweight) to support the goods. The pallet may be raised from the ground on feet or similar construction; the whole pallet or only part of it may be covered with plastics sheet, or treated to reduce susceptibility to water and/or chemicals. <IMAGE>

Description

PALLETS This invention relates to pallets and in particular to a lightweight pallet for use as a carrier board for goods Conventional pallets are generally made of wood, made to size by joining together a set of planks and corner blocks using nails or staples. The conventional pallet construction provides upper load-bearing planks and lower planks forming a base, between which there is space to insert the prongs of a fork-lift truck. Pallets are generally square or rectangular and constructed so that the prongs can be inserted from any side of the pallet.

Conventionally, pallets also often have extras such as legs, runners or separate components requiring subsequent assembly with consequent extra cost. Such pallets are relatively expensive to make, so when they are damaged or broken in the course of use, they are sent for repair rather than being thrown away or otherwise disposed of.

Repair of conventional pallets is again costly and labour intensive with the pallet being withdrawn from profitable use during repair.

In a first aspect, the present invention provides a pallet for use as a carrier board for goods including a portion which comprises two face sheets held apart by an open structure comprising a number of cells or channels defined by walls running substantially perpendicular to and between the face sheets, the walls being made from a thin material penetrable by the prongs of a fork-lift truck enabling the prongs to pass through the open structure with ease.

In contrast to conventional pallets, the pallets of the present invention need not have preformed bores for receiving the fork prongs. Instead, the prongs make their own bores as they are driven laterally into the open structure. The present invention in a further aspect, accordingly provides a pallet structure comprising upper and lower spaced apart face sheets and an intermediate cellular or channelled open structure defined by walls of thin penetrable material extending between the face sheets and having two bores therein formed by insertion into the open structure of the prongs of a fork-lift truck with rupture of the penetrable material. Forming the prong reception bores this way is advantageous as they automatically fit tightly round the prongs and lateral slippage of the loaded pallet relative to the fork-lift truck fork is hindered.

The present invention also provides, in a further aspect, a method of carrying a load using a fork-lift truck which comprises locating the load on a pallet including a portion which comprises two face sheets held spaced apart by walls of thin penetrable material defining a cellular or channelled open structure, driving the prongs of the fork-lift truck into the cellular or channelled open structure with rupture of some cell or channel walls thereof, and lifting the pallet and its load by raising the fork of the fork-lift truck.

Pallets according to this invention have several advantages over prior art conventional pallets for moving or storing goods. They are low in material cost, easy to produce, have a simple modular form, can be cut to any desired shape or size from a basic slab and can if desired be made sufficiently inexpensively to enable them to be regarded as throwaway items. They can also be constructed to give freedom from splinters, to be light in weight and accordingly easy to carry, so that they do not damage goods and with no rough edges.

The open structure between the face sheets, which is preferably a honeycomb structure, though other types may be used, has anisotropic strength. In directions parallel to the planes of the sheets it is weak, allowing penetration by the prongs, but the strength in a direction perpendicular to the sheets is high, so the lower face sheet supports the weight of the load via the open structure and the upper face sheet without the open structure being crushed.

In use of the pallet, the prongs of a fork-lift truck can simply be driven into the open structure between the upper and lower face sheets. Although this damages part of the open structure, the remaining open structure in the loaded pallet is strong enough to support the weight of the load on the upper face sheet.

The prongs of the fork-lift truck can be inserted from any side of the pallet, the open structure being of a generally uniform weakness in this lateral direction.

The portion comprising the two face sheets held apart by the open structure may constitute the entire pallet as such or it may form a deck onto which goods are loaded, the deck being supported on feet, beams or other support members, either made of conventional materials or themselves made of face sheets with open structure material between the face sheets. In such cases, the pallet may be lifted either by inserting the prongs into the penetrable open structure or by inserting them below the deck between the support members (or through them if they are also of penetrable construction). Alternatively, the prong-penetrable portion can be used to form a base to support a deck. In the latter case, the base can be made up of a plurality of elongate members, each member having an open structure into which the prongs of a fork-lift truck can penetrate.

The pallets of the invention may be used once or repeatedly. If used more than once, the prongs of the fork-lift truck are preferably reinserted in the same place as before to reduce the rate of destruction of the open structure.

Since these pallets can be made relatively cheaply, they can simply be replaced when they are damaged, saving on expensive repairs and loss of a pallet for the duration of repair.

Pallets according to this invention can be made to the size desired or larger units can be assembled and readily cut by hand or machine to form pallets of desired sizes and shapes.

Preferably pallets of the invention are made from inexpensive paper products, for example, stiff paper for the open structure and corrugated cardboard (i.e. flat sheets consisting of or including two flat paper or card plies adhered to either side of a corrugated or solid cardboard) for the face sheets. The low cost of these materials results in a low cost pallet which provides a cheap alternative to conventional pallets, particularly for the moving or storage of lightweight goods, goods of a homogeneous nature such as flat boards, boxes etc.

Advantageously corrugated or solid cardboard sheets used according to the invention may be plastics coated or otherwise waterproofed or weatherproofed so that the resultant pallet has some resistance to rain, for example by chemical impregnation of the material prior to construction of the pallet or by treatment of the completed pallet by spraying or dipping with a water repellant chemical.

Alternatively, the top, bottom or both top and bottom of the pallet may be protected against water, e.g. from rain or from the pallet being put down in a puddle, by covering with a plastics sheet, for example by shrinkwrapping, vacuumforming against the pallet itself, or by adhesion of sheet or preformed shaped plastics material thereto.

The open structure can be made from stiff sheets of paper or card glued together at intervals between alternate sheets so that when the glued sheets are stretched apart they form an open structure of substantially parallel cells. The open structure can also be made from stiff sheets of paper or card arranged to define substantially parallel channels between the face sheets, where the walls of the channels are corrugated the corrugations run from one face sheet to the other. Preferably, the open structure is a honeycomb structure. It may also be a structure having generally diamond shaped, square, rectangular or even cylindrical cells, but any structure having a generally regular repeating shape or shapes in cross section is suitable. The open structure can be made from other thin penetrable materials such as foil or plastics.

For a better understanding of the invention, reference will now be made to the accompanying drawings in which: Figure 1 shows a perspective view of part of a pallet with part of one face sheet broken away; Figure 2 shows a perspective view of a pallet incorporating a base, and Figure 3 shows an alternative pallet construction, part cut away.

Referring to Figure 1, the pallet 1 consists of two face sheets 2, e.g. of plastics coated corrugated cardboard and a honeycomb structure 3 between them. A corner of one of the face sheets has been broken away in the drawing to show the honeycomb structure 3.

The open honeycomb structure 3 is formed of strips of card glued together. The structure is secured between the face sheets 2 with adhesive. Adhesive can be applied to an inner surface of a face sheet or to the rims of the cell walls or to both before the face sheets and open structure are stuck together.

The resultant pallet is strong enough to support the weight of the load but the open honeycomb structure is easily penetrated in a direction parallel to the face sheets 2 by the prongs of a fork-lift truck when the loaded pallet is to be moved, i.e. in directions x and y in Figure 1.

As will be appreciated, the face sheets 2 of the pallet are the same so the pallet can be used either way up. If desired, the face sheets 2 may be different, e.g. to give different indentation resistance to the upper sheet.

Convenient dimensions of a pallet according to the invention are 1 metre x 1 or 2 metres x 10 centimetres, and 1 metre x 1.2 metres x 10 centimetres. If desired, smaller sizes can be cut from larger slabs.

Figure 2 illustrates a further embodiment of a pallet according to the invention. A pallet 10 comprises a deck 11 and five support members 12, 13, 14, 15 and 16. The support members 12 to 16 comprise an open structure intermediate two face sheets. These members can be cut from a pallet as described in Figure 1 and bonded to the deck 11. The deck 11 is a sheet of thin card and is suitable for a rigid flat load. Alternatively, the deck 11 can be a sheet of corrugated cardboard or similar material.

In the embodiment of Figure 2, in order to lift the pallet 10, the prongs of a fork-lift truck may be inserted into any one of the support members 12 to 15 penetrating the open honeycomb structure. The pallet 10 can be re-used either by reinserting the prongs in the same place as before, or by penetrating another of the support members.

Instead of using thin card or corrugated cardboard for the deck 11, a pallet similar to that described with reference to Figure 1 can be bonded onto the base. This provides a more rigid structure which can take an unevenly distributed load.

The pallets of Figures 1 and 2 can be used easily on roller conveyor systems as they can run on the rollers when placed in any orientation relative to the conveyor system.

It may be desired that the pallet of Figure 1 be raised from the ground or surface on which it is to be placed, this providing additional flexibility as the pallet may then be lifted by the fork lift truck either by inserting the prongs into the penetrable material or by inserting them underneath the pallet. Pads cut from a slab of pallet material can be bonded to the undersurface of the pallet to provide it with "feet". Such a pallet can be waterproofed by applying a vacuum formed or stretched form film to its undersurface including the "feet". The film applied has no structural strength. Alternatively, individual pieces of film can be applied to each "foot" to waterproof it.

Additionally, the upper surface of the pallet can be covered with a vacuum formed film membrane to render the pallet weatherproof.

Figure 3 shows a specific example of such a pallet. In this Figure, the pallet shown consists of an upper deck 20 consisting of upper 21 and lower 22 skins of card adhered either side of an expanded honeycomb core 23, and nine feet adhered to the underside of the skin 22, each foot consisting of upper 25 and lower 26 skins of card adhered either side of an expanded honeycomb core 27. The underside of the pallet is covered with a shrunk-on waterproof plastics sheet 28. The number of feet may be varied to suit the particular use envisaged.

In place of the honeycomb open structure shown, similar cellular structures with cells of other cross-sectional shapes, such as square, rectangular, triangular, diamond, circular or of irregular cross section may be used, the cellular structure providing a generally uniform support for the upper load-bearing face sheet so as to transmit the weight to the lower face sheet.

The preferred materials of construction are paper products but other sheet materials such as plastics sheets can be used. The face sheets can also be made from plywood, metal, chipboard or hardboard. Naturally, any material used can be waterproofed by applying a water impermeable coating or membrane.

Claims

1. A pallet for use as a carrier board for goods including a portion which comprises two face sheets held apart by an open structure comprising a number of cells or channels defined by walls running substantially perpendicular to and between the face sheets, the walls being made from a thin material penetrable by the prongs of a fork-lift truck enabling the prongs to pass through the open structure with ease.

2. A pallet according to claim 1 wherein the portion comprises a deck onto which goods are loaded.

3. A pallet according to claim 1 wherein the portion comprises a base which supports a deck onto which goods are loaded.

4. A pallet according to claim 3 wherein the base comprises a plurality of elongate support members into which the prongs of a fork-lift truck penetrate.

5. A pallet according to any preceding claim wherein the open structure is made from stiff sheets of paper or card glued together at intervals between alternate sheets so that when the glued sheets are stretched apart they form an open structure of substantially parallel cells.

6. A pallet according to any one of claims 1 to 5 wherein the open structure is a honeycomb.

7. A pallet according to any one of claims 1 to 5 wherein the open structure has diamond cross section cells.

8. A pallet according to any one of claims 1 to 7 wherein the cells are cylindrical.

9. A pallet according to any preceding claim wherein the face sheets are of corrugated cardboard.

10. A pallet according to claim 9 wherein the corrugated cardboard is plastics coated.

11. A pallet according to any preceding claim wherein the face sheets are of solid cardboard, hardboard, plywood or metal.

12. A pallet according to any preceding claim wherein the face sheets are treated to increase water resistance.

13. A pallet structure comprising upper and lower spaced apart face sheets and an intermediate cellular or channelled open structure defined by walls of thin penetrable material extending between the face sheets and having two bores therein formed by insertion into the open structure of the prongs of a fork-lift truck with rupture of the penetrable material.

14. A pallet structure comprising a deck and a plurality of supporting feet attached thereto, either or both being made of upper and lower spaced apart face sheets and an intermediate cellular or channelled open structure defined by walls of thin penetrable material extending between the face sheets, and over at least the supporting feet a waterproof cover.

15. A pallet structure according to claim 15 wherein the waterproof cover extends across the whole of the lower face of the deck and the feet thereon.

16. A method of carrying a load using a fork-lift truck which comprises locating the load on a pallet including one or more portions consisting of two face sheets held spaced apart by walls of thin penetrable material defining a cellular or channelled open structure, driving the prongs of the fork-lift truck into the cellular or channelled open structure with U'pture of some cell or channel walls thereof, and lifting the pallet and its load by raising the fork of the fork-lift truck.

17. A pallet substantially as hereinbefore described with reference to Figure 1 of the accompanying drawings.

18. A pallet substantially as hereinbefore described with reference to Figure 2 of the accompanying drawings.

19. A pallet substantially as hereinbefore described with reference to Figure 3 of the accompanying drawings.