GB2275251A

GB2275251A - Plastic pallet

Info

Publication number: GB2275251A
Application number: GB9303356A
Authority: GB
Inventors: Paul Charles Lanfear; Alan Boulger
Original assignee: Individual
Current assignee: Individual
Priority date: 1993-02-19
Filing date: 1993-02-19
Publication date: 1994-08-24
Also published as: GB9303356D0

Abstract

A plastics pallet is of fabricated construction, so that it is economic to produce and can readily be repaired if damaged. Essentially, it comprises a planking platform 10 which itself may be of plastics, supported on two or more beams 12. Each of the beams comprises an upper and a lower plastics plank 18, 20 and a series of plastics columns 22 sandwiched between the upper and lower planks, and means are provided for connecting the upper and lower planks together, so as to constitute a beam from the upper and lower planks and the columns separating them. The planks are of extruded cellular structure and the spacers are preferably of conical shape. <IMAGE>

Description

INDUSTRIAL PALLET An industrial pallet essentially comprises a platform supported on feet or beams which space the platform from any supporting surface (e.g. the ground; the platform of a transport flat or container or a package on an underlying pallet). Traditionally, industrial pallets have been made of timber and comprise a series of laterally spaced timber beams or joists and a platform made of planking extending across and nailed or screwed to the joists.

More recently, moulded plastics pallets have been produced, but the cross-sectional structure necessary to give adequate strength is complicated, and as a result, the moulded pallet is very expensive. Another disadvantage of the moulded pallet is that, if it is damaged, it cannot be repaired. For these reasons at least, moulded plastics pallets have not generally found favour.

It is the primary object of the present invention to provide a plastics industrial pallet which is economic to manufacture.

According to this invention, an industrial pallet comprises a planking platform, supported on two or more beams, each beam comprising upper and lower plastics planks and a series of discrete plastics columns located between the upper and lower plastics planks and spaced apart longitudinally of those planks, and means securing the upper and lower plastics planks together, so that the columns are sandwiched between the upper and lower plastics planks.

The upper and lower plastics planks are preferably extruded sections with a cellular cross-section. A suitable cross-section comprises a series of side-by-side rectangular cross-section cells. Plastics end pieces are preferably provided for push-in attachment to the ends of the planks to conceal and protect the cellular structure.

The platform planking may also comprise plastics planks and preferably the upper and lower planks of the beams and the platform planking are formed from the same extruded plastics section.

According to a preferred feature of the invention, each column is generally cylindrical; it may however be partconical, in which case the larger diameter end is arranged at the bottom. Preferably each column has flat end pieces, which bear against the faces of the upper and lower planks. In a preferred construction, each column comprises a part-conical peripheral wall, a central cylindrical strut; radial walls between the strut and the wall and end pieces joining the wall to the strut and flush with the ends of the wall.

The means for securing the upper and lower planks together preferably comprises a series of bolts, each passing through at least one wall of the lower plank, then through one of the columns, through the upper plank and through the bottom wall of one of the platform planks, and a nut engaging on the bolt and located within the platform plank or the lower plank.

In the preferred construction, the spacing of the columns from each other enables the tynes of a forklift to engage with the pallet from any one of its four sides (i.e.

between the beams from two ends and between the columns of the beams from the two sides), thus providing a four-way pallet.

An industrial pallet in accordance with the invention will now be described by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a cross-section through a part of the pallet, showing the construction of a beam, Figure 2 is a perspective view, showing the construction of a moulded plastics column, Figure 3 is an elevation to a smaller scale of the completed pallet, looking on one side, and Figure 4 is an elevation of the completed pallet shown in Figure 3, looking on one end.

The pallet which is illustrated in the drawings is made as a fabrication from a series of components, held together by mechanical fastening devices, which in this particular construction are screw devices. The fabricated nature of the construction is important, because it avoids the use of very expensive dies, as are necessary with a moulded product. Another important advantage of the fabricated structure is that, if the pallet is damaged in use, it is possible to dismantle it, and replace the damaged component. This, of course, is not possible with a moulded article.

Essentially, the pallet comprises a planking platform 10, which is supported on a series of beams 12. In this particular arrangement, the platform 10 comprises a series of identical planks 14, in a side-by-side arrangement, with small gaps 16 between them - see Figure 3. Each of the planks 14 extends through the full length of the pallet, as shown in Figure 4, and the complete assembly of planks determines the overall width of the pallet, as seen in Figure 3.

Each of the beams 12 comprises an upper plank 18, a lower plank 20 and a column 22, the upper and lower planks 18 and 20 being secured together so as to sandwich the columns 12 between them. As seen in Figure 1, each of the planks 18 and 20 is formed as a cellular plastics extrusion, and in effect comprises a series of side-byside longitudinally extending rectangular cells 24. This is a known construction of a plastics plank, and the cellular construction gives the plank a comparative light weight, whilst at the same time maintaining substantially the same strength as a solid plastics plank of the same external dimensions.

The column 22 is a moulded plastics item, comprising a part conical peripheral wall 24, a central tubular column 26, four radial walls 25 and upper and lower end plates 28 and 30. As clearly shown in Figure 2, the upper end plates 28 are relatively thin-walled, flat plates of substantially triangular shape, each subtending an angle of approximately 90" around the axis of the column 22, and being formed integral with both the central strut 26 and the outer wall 24. The radial walls 25 extend from the radial edges of the plates 28 along the length of the column. At the lower end, there are two similarly shaped plates 30, excepting that they are located at positions displaced through 90" from the plates 28. In other words, the plates 30 are aligned with the spaces between the plates 28.It is an important feature of the construction of the columns 22, that the end faces of the plates 28 and 30 are flush with the respective ends of the outer peripheral wall 24, so that they provide extended flat bearing surfaces for engagement with the undersurface of the upper plank 18 and the upper surface of the bottom plank 20, when the column 22 is sandwiched between the planks 18 and 20. The end plates 28 and 30 and the radial walls 25 combine to give a rigid structure to the column 22.

A metal or plastics bolt 30, having a square head 32, passes through a hole 34 in the top wall of the lower plank 20; through the column 30, then through holes 36 formed in the top and bottom walls of the upper plank 18 and through a hole 35 in the bottom wall of the plank 14 which crosses over the top plank 18. This bolt engages with an expansible nut 37 of known construction, which is located within the plank 14. It is necessary to form a large hole 40 through the bottom wall of the lower plank 20, to allow the head of the bolt 32 to pass through, and it will be appreciated that the holes 34, 36, 35 and 40 are formed in the upper and lower planks 18 and 20 during the construction of the pallet.

Each of the beams 12 provided by the particular construction illustrated in Figures 1 and 2 has four columns 22 arranged as shown in Figure 3, that is to say there is one column adjacent to each end of the beam, and two central columns arranged close to each other, but one on each side of the centre of the length of the beam, but the number and disposition of the columns can be varied.

Moreover, the length of the beam corresponds to the overall width of the platform 10, as is clear from Figure 3. As is clear from Figure 3, a plank 14 is located centrally over each of the columns 22 and in this particular example, there is one plank 14 between the central columns and two such planks between the central columns and each of the end columns. It is to be understood, however, that other arrangements are possible and a plank 14 need not be located exactly over a column 22.

The pallet has three beams 12, as is clear from Figure 4, two of these being arranged near to respective longitudinal ends of the planks 14 forming the platform 10, the third one comprising a central beam 12 extending across the planks 14 at the centre of the length of the platform 10. The spacing of the beams 12, as illustrated in Figure 4, is such that the tynes of a forklift can be inserted in the spaces between the beams 12, and the spacing of the columns 22 in each beam 12, as illustrated in Figure 3, is such that the tynes of a forklift device can be inserted in the spaces between each end column 22 and the nearest of the two centre columns 22. Hence, a forklift mechanism can be used with the pallet from either side or from either end, so that the pallet is a true four-way pallet.

Each of the planks 14 used to make up the platform 10 is formed from the same plastics extrusion as that used to provide the planks 18 and 20 for the beams 12. One of the advantages of the construction is, therefore, that the pallet is constructed entirely from a single type of planking, plus a number of the moulded columns 22, with the necessary mechanical fastening devices. The platform 10 is secured to the beams 12 by the bolts 30 and by set screws which are located in the upper plank 18 and engage with expansible nuts in the planks 14 which are not located over columns 22.

An end piece 50 is provided at each end of each of the planks 14, 18 and 20. It is a moulded plastics blanking plate with spigots which are a press fit in the end of one of the planks and serves to close the end of the plank so that the cellular construction is not exposed.

The planks 20 may as an alternative extend completely around the base of the platform 10 to provide extra rigidity. Such an arrangement is as shown in broken lines in Figure 4.

It should be understood that the platform is not necessarily made of plastics planks: it could be of timber planking or even sheet metal.

The pallet is of relatively light weight but has considerable strength: for instance, a pallet one metre square will safely carry a load of 2,700 kilogrammes.

However, it is much cheaper than a moulded plastics pallet of equivalent performance, and if, for example, one of the planks 14 is badly damaged, that plank can be removed and readily replaced.

Claims

CLAINS

1. An industrial pallet comprising a planking platform, supported on two or more beams, each beam comprising upper and lower plastics planks and a series of discrete plastics columns located between the upper and lower plastics planks and spaced apart longitudinally of those planks, and means securing the upper and lower plastics planks together, so that the columns are sandwiched between the upper and lower plastics planks.

2. An industrial pallet as claimed in claim 1, in which the upper and lower plastics planks are extruded sections with a cellular cross-section.

3. An industrial pallet as claimed in claim 2, in which the upper and lower plastics planks have a cross section which comprises a series of side-by-side rectangular cross-section cells.

4. An industrial pallet as claimed in claim 2 or claim 3, in which plastics end pieces are provided for push-in attachment to the ends of the planks to conceal and protect the cellular structure.

5. An industrial pallet as claimed in any one of claims 1 to 4, in which the platform planking also comprises plastics planks.

6. An industrial pallet as claimed in claim 5, in which the upper and lower planks of the beams and the platform planking are formed from the same extruded plastics section.

7. An industrial pallet as claimed in any one of claims 1 to 6, in which each column is generally cylindrical.

8. An industrial pallet as claimed in claim 7, in which each column is part conical, and the larger diameter end is at the bottom.

9. An industrial pallet as claimed in any one of claims 1 to 8, in which each column has flat end pieces, which bear against the faces of the upper and lower planks.

10. An industrial pallet as claimed in claim 9, in which each column comprises a part-conical peripheral wall, a central cylindrical strut; radial walls between the strut and the wall and end pieces joining the wall to the strut and flush with the ends of the wall.

11. An industrial pallet as claimed in any one of claims 1 to 10, in which the means for securing the upper and lower planks together comprises a series of bolts, each passing through at least one wall of the lower plank, then through one of the columns, through the upper plank and through the bottom wall of one of the platform planks, and a nut engaging on the bolt and located within the platform plank or the lower plank.

12. An industrial pallet as claimed in any one of claims 1 to 11, in which the spacing of the columns from each other enables the tynes of a forklift to engage with the pallet from any one of its four sides, thus providing a four-way pallet.

13. An industrial pallet constructed and arranged substantially as herein described with reference to the accompanying drawings.