HK1176339B

HK1176339B - Wooden pallet with nail plates and related methods

Info

Publication number: HK1176339B
Application number: HK13103345.1A
Authority: HK
Inventors: Dan Lantz; Ken Brandt
Original assignee: Chep Technology Pty Limited
Priority date: 2009-12-08
Filing date: 2010-12-08
Publication date: 2017-05-05

Description

Wooden pallet with nail plate and related method

Related application

This application claims the benefit of U.S. provisional application No. 61/267,664, filed on 8.12.2009, the entire contents of which are incorporated herein by reference.

Technical Field

The present invention relates to the field of pallets, and more particularly to wood pallets having improved resilience to impacts with material handling equipment, and to methods of producing the same.

Background

Conventional wooden pallets include a base layer and a cargo layer separated by support blocks. Conventionally, the base and cargo layers each have end deck boards assembled on connector boards that extend along the entire length or width of the pallet. The end deck boards are nailed into the support blocks via connector boards to build the basic structure of the pallet. The end deck boards are also referred to as runners, and the connecting boards are also referred to as longitudinal boards.

To move a wooden pallet with cargo above, the forklift tines are inserted into the gap between the base and the cargo layer. If the forklift fails to stop in real time, the forklift may impact one of the end deck boards of the pallet. Impacts such as these weaken the pallet and significantly reduce the life of the pallet, thereby causing the pallet to have to be repaired more frequently and/or to fail before its expected life cycle is reached.

In an attempt to improve pallet durability, nail plates have been used to strengthen wooden pallet joints. Bas in US7,056,074 discloses a pegboard between the upper surface of a support block and a board in the cargo layer and between the lower surface of a support block and a board in the base layer. Each nail plate includes protrusions extending from its upper and lower surfaces and a central opening for receiving a connecting device. A separate connecting device is used for each support block to couple the cargo to a corresponding plate in the base plate to each support block with the corresponding nail plate penetrating to the opposite wood surface.

Similarly, Roger in US6,584,915 discloses nail plates for strengthening wood pallet joints. The nail plate is between the end deck plate and the support blocks, wherein the projections from the nail plate are embedded in the support blocks. In particular, the projections of each nail plate are grouped into two groups to leave a central or middle region free of any projections. The staples are driven through a central or middle region of the staple plate.

Yet another use of nail plates is disclosed in U.S. patent US7,516,705 to Hedstrom. The' 705 patent is assigned to the present assignee of the present invention and is incorporated herein by reference in its entirety. The nail plate is between the connecting plate and the supporting block, wherein the projection from the nail plate is embedded in the connecting plate.

Even in view of the above nail plates, there is still a need to further improve the resilience of wood pallets to impacts from material handling equipment.

Disclosure of Invention

In view of the foregoing background, it is therefore an object of the present invention to provide a wood pallet that is resilient to impacts generated by material handling equipment.

This and other objects, advantages and features in accordance with the present invention are provided by a wood pallet comprising a base layer and a cargo layer. The cargo layer includes a pair of spaced apart connector boards and a pair of spaced apart end deck boards orthogonal to the pair of connector boards. The respective ends of the pair of end deck boards overlap the respective ends of the pair of connector boards. The nail plates are coupled between respective ends of the pair of connection plates and respective ends of the pair of end deck boards. Each nail plate has a first surface with a projection extending outwardly therefrom and embedded in one of the end deck boards and a second surface opposite the first surface without any projection and contacting an end of one of the connector boards. The spaced apart support blocks are positioned between the base layer and the pair of connector boards in the cargo layer and form a gap therebetween for receiving a lifting member.

The cargo layer further includes a plurality of spaced apart intermediate deck boards positioned between the pair of end deck boards and coupled to the pair of connector boards, defining a clearance area between an inner edge of each end deck board and an adjacent one of the intermediate deck boards. Each nail plate includes a bracket extending in the gap area and contacting an inner edge of one of the end deck boards to absorb impact against an outer edge thereof.

The bracket is triangular with an open interior. An upper corner of the inner edge of each end deck plate is cut; and wherein an upper tip portion of the bracket is bent into the cutout. The upper tip portion is coplanar with an upper surface of the end deck plate.

Each nail plate is stamped from a single metal sheet. The plurality of projections include rounded tip portions. The plurality of protrusions are arranged in rows and columns. The rows and columns have a zigzag pattern.

The pallet further includes a plurality of fasteners coupling the pair of end deck boards and the pair of connector boards to the plurality of support blocks.

The base layer includes a pair of spaced apart end deck boards and a pair of spaced apart connector boards orthogonal to the pair of end deck boards. The pair of end deck boards do not overlap the pair of connector boards. The pallet further includes a plurality of nail plates coupled between respective ends of the pair of end deck boards and the plurality of support blocks. Each nail plate has a first surface including a plurality of projections extending outwardly therefrom and embedded in one of the end deck boards and a second surface opposite the first surface and free of any projections and contacting a support block.

The wooden pallet further comprises a plurality of nail plates coupled between the respective ends of the pair of connection plates and the plurality of support blocks. Each nail plate has a first surface including a plurality of protrusions extending outwardly therefrom and embedded in an end of one of the connecting plates, and a second surface opposite the first surface without any protrusions and contacting a support block.

Another concept of wood pallets relates to nail plates, wherein each nail plate has a length corresponding to the length of an end deck board. This simplifies the manufacturing process.

Yet another concept relates to a method for manufacturing the above-described wood pallet.

Drawings

Fig. 1 is a top perspective view of a pallet with accented block sections illustrating nail plates according to the present invention.

Fig. 2 is a partial block diagram of the pallet shown in fig. 1.

Fig. 3 is a top perspective view of a pegboard according to the present invention.

Fig. 4 is a side view of one of the emphasized block sections shown in fig. 1.

Fig. 5 is a partially exploded perspective view of a pallet having nail plates on the ends and in the midsection of the upper end deck boards according to the present invention.

Fig. 6 is a partially exploded perspective view of a pallet having nail plates only on the ends of the upper end deck boards according to the present invention.

Fig. 7 is a partially exploded perspective view of a pallet according to the present invention having a single nail plate extending the length of the upper end deck board body.

FIG. 8 is a top perspective view of a nail plate having a carrier according to the present invention.

Fig. 9 is a side view, in part, of a pallet illustrating the pegboard having the pallet of fig. 8.

Fig. 10 is a flow chart illustrating a method for manufacturing a pallet according to the present invention.

Detailed Description

The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like reference numerals refer to like elements throughout, and prime (') and double prime (") designations are used to indicate like elements in alternative embodiments.

Referring initially to fig. 1-4, the pallet 10 includes a base layer 20, a cargo layer 30, and a plurality of support blocks 40. The support blocks 50 are coupled between the base layer 20 and the cargo layer 30 and define a space 50 therebetween for receiving a lifting member of a material handling apparatus, such as a stacking tine of a forklift.

The cargo layer 30 includes a pair of spaced apart upper connector boards 32 and a pair of spaced apart upper end deck boards 34 orthogonal to the upper connector boards, so that the cargo layer has a rectangular shape. The upper connector boards 32, also referred to as longitudinal boards (stringerboards), extend the entire length of the pallet 10. The ends of the upper connector plates 32 are between the support plates 40 and the upper end deck boards 34. In other words, the upper connector plate 32 and the upper end deck boards 34 are not coplanar. The cargo layer 30 further includes a separate intermediate upper deck board 36 coupled to the upper connector board 32. The intermediate upper deck boards 36 are substantially parallel to the upper end deck boards 34.

The base layer 20 comprises a pair of spaced apart lower end deck boards 24 and a pair of spaced apart lower connector boards 22 orthogonal to the lower end deck boards, and thus also has a rectangular shape. The lower connector plate 22 is coplanar with the lower end deck plate 24. In other words, the lower end deck boards 24 contact the support blocks 40 and the lower connector boards 22 contact the support blocks 40.

In particular, the nail plates 50, 52 are used in the base layer 20 and the cargo layer 30 to increase the resilience of the pallet 10, as highlighted by the block section 60 in fig. 1. In addition, a block partial view of the pallet 10 is provided in fig. 2.

In the cargo layer 30, the nail plate 50 is between the upper end deck boards 34 and the upper connector boards 32. In the base layer 20, the nail plate 50 is located between the lower end deck boards 24 and the support blocks 40, and the nail plate 52 is located between the lower connector boards 22 and the support blocks 40. It will be apparent to those skilled in the art that the pegboard 50 in the cargo layer 30 may be used without pegboards 50, 52 in the base board 20, and vice versa.

As best illustrated in fig. 3, each nail plate 50 is formed from a sheet of metal in which a flange is stamped so that it forms a tab 56. The nail plate 50 may be stamped from a single sheet of metal. The tab 56 extends outwardly from the sheet metal at a right angle. The tab 56 is located on one side of the sheet metal. The other side of the metal sheet is flat and without any protrusions 56. This allows the nail plates 50, 52 to be applied to their respective boards prior to assembly of the pallet 10.

In the illustrated embodiment, the nail plate 50 is about 100 mm x100 mm (i.e., about 4x4 inches). The peg board 52 is smaller in size because it covers a limited area. In the illustrated embodiment, the nail plate 52 is approximately 25 mm x25 mm (i.e., 1x4 inches). The size of the nail plates 50, 52 may vary depending on the desired application, as will be immediately apparent to those skilled in the art.

The sheet metal used to form the nail plates 50, 52 has a thickness in the range of, for example, about 1 to 5 millimeters. The thickness of the nail plates 50, 52 does not prevent the nail portion 60 or other locking means from passing therethrough. The length of the protrusion 56 is in the range of, for example, about 5 to 15 millimeters.

The tips of the projections 56 of the peg plates 50, 52 are bent/rounded. This advantageously reduces the risk of injury to the pallet 10 from losing wood to the point where the projections from the pegboard are exposed. The projections 56 in the illustrated nail plate 50 are in a saw-tooth pattern. As one of ordinary skill in the art will readily appreciate, the protrusions are not limited to a zig-zag pattern. For example, the projections may be arranged in rows, arcs, and/or columns, which may be uniformly spaced, and non-uniformly spaced.

Referring now to fig. 4, the projections 56 of the nail plates 50, 52 are embedded in the upper end deck boards 34, the lower end deck boards 24, and the lower connector boards 22. In contrast, the flat sides of the pegboard 50, 52, respectively, are not embedded in the wood surface in contact therewith. This particular configuration of the nail plates 50, 52 and their placement advantageously evenly distributes the load to avoid tearing of the plate body, which in turn leads to cracking or splitting of the wood over time. The nail plates 50, 52 also help reduce elevated nails, pallet deformation and aging. Additionally, the nail plates 50, 52 may help maintain the original size and squareness of the pallet while providing improved shear resistance and bending performance to the board.

As shown in fig. 5, the pegboard 50 in the cargo layer 30 is located above the outer and inner support blocks 40. The lower surface 62 of the upper end deck boards 34 illustrates the placement of three nail plates 50. Alternatively, the peg board 50 above the center support block 40 may be omitted, as shown in fig. 6.

In a different embodiment, the nail plate 50' is a single piece, and therefore extends substantially the length of the upper end deck boards 34, as shown in fig. 7. The same positioning and configuration of the pegboard 50' in the cargo layer 30 may also be applied in the base layer 20. However, the peg board 52 embedded in the lower web 22 remains as a separate item.

To further increase the resiliency of the pallet 10, a higher density wood may be selected to form the upper and lower end deck boards 34, 24 and the lower connector boards 22. The pallet 10 is further able to withstand longer impacts by the use of higher density wood in combination with the nail plates 50, 52. This also results in preferred shear resistance and bending performance of the load board/pallet.

In other words, the strength and durability of the pallet 10 increases as wood density increases. One wood density species is "dense cork", which generally comprises a wood having a density of about 500 to 650kg/m³Wood of a density within the range of (1). Such wood includes, for example, southern yellow pine. Another wood density species is "densified hardwood," which typically comprises from about 650 to 800kg/m³Wood of a density within the range of (1). Such woods include, for example, oak, beech, ash, maple, cherry, teak, rubber and peach.

It is immediately obvious to those skilled in the art that wood density and the elimination of tear initiation (due to the nail plates 50, 52) are critical to reduce damage to both the upper end deck boards 34 and the lower end deck boards 24. This results in less lost wood to increase customer satisfaction.

Another embodiment of the nail plate 50 "will now be described with reference to fig. 8 and 9. The pegboard 50 "of this configuration is referred to as a pegboard with a cradle 70". The brackets 70 "extend within a clearance area defined between the inner edge of each end deck board 34" and an adjacent intermediate deck board 36 ". The brackets 70 "contact the inner edge of one of the end deck boards 34" to absorb the impact against the outer edge of the same upper end deck board 34 ".

When an impact force is applied to the outer edge of the upper end deck boards 34 ", the force is transferred to the pallets 70" of the nail plates 50 ", and thus the impact energy is distributed over the length of the upper end deck boards 34". The nail plate 50 "with the bracket 70" extends the full length of the upper end deck boards 34 "(as shown in fig. 7) or contacts the respective ends of the upper end deck boards 34" only in sections (as shown in fig. 6).

The bracket 70' has a triangular shape with an open interior. However, the bracket 70' may have other shapes as would be immediately apparent to one skilled in the art. Each of the nail plate 50 "and the carrier 70" are stamped from a single sheet of metal.

In addition, the upper corner portion 35 "of the inner edge of each end deck panel 34 'is notched, and an upper tip portion 71' of the bracket 70" is bent into the notch to provide an additional area to absorb impact on the outer edge of the same upper end deck panel 34 ". The upper tip portion 71 "is substantially coplanar with the upper surface of the end deck boards 34". The nail plate 50 "and the carrier 70" are stamped from a single piece of sheet metal.

In the illustrated nail plate 50 ", the projections 56" project both upwardly and downwardly. Alternatively, the projections 56 "project only upwardly, or only downwardly.

Another concept relates to a method of manufacturing the pallet 10 described above. Referring now to the flowchart 100 depicted in fig. 10, from the start (block 102), the method includes providing a base layer 20 (at block 104) and providing a cargo layer 30 (at block 106). The cargo layer 30 includes a pair of spaced apart connector boards 32 and a pair of spaced apart end deck boards 34 orthogonal to the pair of connector boards. The pair of end deck boards 34 overlap respective ends of the pair of connector boards 32. At block 108, coupling a plurality of nail plates 50 between respective ends of the pair of end deck boards 34 and the pair of connector boards 32; each nail plate 50 has a first surface including a plurality of projections 56 extending outwardly therefrom and embedded in one of the end deck boards 34 and a second surface opposite the first surface and without any projections and contacting an end of one of the connector boards 32. At block 110, a plurality of spaced apart support blocks 40 are provided between the base layer 20 and the pair of connector boards 32 in the cargo layer 30 with a gap therebetween to receive a lifting member. The method ends at block 112.

Many modifications and other embodiments of the invention will come to mind to one skilled in the art to which this invention pertains having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed and that modifications and embodiments may be resorted to by those skilled in the art.

Claims

1. A wood pallet, comprising:

a base layer;

a cargo layer comprising a pair of spaced apart connector boards, a pair of spaced apart end deck boards orthogonal to the pair of connector boards, and a plurality of spaced apart intermediate deck boards, wherein respective ends of the pair of end deck boards overlap respective ends of the pair of connector boards, the plurality of spaced apart intermediate deck boards being positioned between and coupled to the pair of connector boards, a clearance area being defined between an inner edge of each end deck board and an adjacent one of the intermediate deck boards;

a plurality of nail plates coupled between respective ends of the pair of connection plates and respective ends of the pair of end deck boards, each nail plate including a bracket extending within the gap area and contacting the inner edge of one of the end deck boards to absorb an impact against an outer edge thereof, and each nail plate having a plurality of nail plates coupled between respective ends of the pair of connection plates and respective ends of the pair of end deck boards

A first surface comprising a plurality of projections extending outwardly therefrom and embedded in the end deck boards, and

a second surface opposite to the first surface without any protrusion and contacting the connection plates; and

a plurality of spaced apart support blocks located between the base layer and the pair of connector boards in the cargo layer and forming a gap therebetween to receive a lifting member.

2. The wood pallet according to claim 1 wherein each bracket is triangular with an open interior.

3. The wood pallet according to claim 1 wherein an upper corner of the interior edge of each end deck board is notched; and wherein an upper tip portion of each bracket is bent into the cutout.

4. The wood pallet according to claim 3 wherein each upper peak is coplanar with an upper surface of each end deck board.

5. The wood pallet according to claim 1 wherein each nail plate is stamped from a single metal sheet.

6. The wood pallet according to claim 1 wherein the plurality of projections comprise rounded tips.

7. The wood pallet according to claim 1 wherein the plurality of projections are arranged in rows and columns.

8. The wood pallet according to claim 7 wherein the rows and columns have a zigzag pattern.

9. The wood pallet according to claim 1 further comprising a plurality of fasteners coupling the pair of end deck boards and the pair of connector boards to the plurality of support blocks.

10. The wood pallet according to claim 1 wherein the base layer comprises a pair of spaced apart end deck boards and a pair of spaced apart connector boards orthogonal to the pair of end deck boards, wherein the pair of end deck boards and the pair of connector boards are non-overlapping; and this wooden pallet still contains a plurality of nail boards, and this a plurality of nail boards are coupled between this tip and these a plurality of supporting shoes respectively to the end deck plate body, and each nail board has:

a first surface comprising a plurality of projections extending outwardly therefrom and embedded in the end deck boards; and

a second surface opposite to the first surface and without any protrusion, and contacting one of the plurality of support blocks.

11. The wood pallet according to claim 10 further comprising a plurality of nail plates coupled between the support blocks and respective ends of the pair of connector plates of the base layer, each nail plate having

A first surface including a plurality of protrusions extending outwardly therefrom and embedded in the connection plates; and

a second surface opposite to the first surface without any protrusion and contacting one of the plurality of support blocks.

12. A wood pallet, comprising:

a base layer;

a pair of spaced apart nail plates coupled between the respective ends of the pair of connector plates and the respective ends of the pair of end deck boards, each nail plate having a length corresponding to the length of each end deck board, each nail plate including a bracket extending within the gap area and contacting the inner edge of one of the end deck boards to absorb impact against an outer edge thereof, and each nail plate having a bracket extending between the respective ends of the pair of connector plates and the respective ends of the pair of end deck boards

A first surface comprising a plurality of projections extending outwardly therefrom and embedded in one of the end deck boards; and

a second surface opposite to the first surface without any protrusion and contacting the ends of the pair of connection plates; and

13. The wood pallet according to claim 12 wherein each bracket is triangular with an open interior.

14. The wood pallet according to claim 12 wherein an upper corner of the interior edge of each end deck board is notched; and wherein an upper tip portion of each bracket is bent into the cutout.

15. The wood pallet according to claim 14 wherein each upper peak is coplanar with an upper surface of each end deck board.

16. The wood pallet according to claim 12 wherein the plurality of projections comprise rounded tips.

17. The wood pallet according to claim 12 wherein the base layer comprises a pair of spaced apart end deck boards and a pair of spaced apart connector boards orthogonal to the pair of end deck boards, wherein the pair of end deck boards and the pair of connector boards are non-overlapping; and this wooden pallet still contains a plurality of nail boards, and these a plurality of nail boards are coupled between these a plurality of supporting shoes and this to the tip respectively of end deck plate body, and each nail board has:

18. The wood pallet according to claim 12 further comprising a plurality of nail plates coupled between respective ends of the pair of connector plates and the plurality of support blocks, each nail plate having a plurality of nail plates

19. A method for manufacturing a wood pallet, comprising:

providing a substrate layer;

providing a cargo layer comprising a pair of spaced apart connector boards, a pair of spaced apart end deck boards orthogonal to the pair of connector boards, and a plurality of spaced apart intermediate deck boards, wherein respective ends of the pair of end deck boards overlap respective ends of the pair of connector boards, the plurality of spaced apart intermediate deck boards being positioned between and coupled to the pair of connector boards, a clearance area being defined between an inner edge of each end deck board and an adjacent one of the intermediate deck boards;

coupling a plurality of nail plates between the respective ends of the pair of connector plates and the respective ends of the pair of end deck boards, each nail plate including a bracket extending within the gap area and contacting the inner edge of one of the end deck boards to absorb an impact against an outer edge thereof, each nail plate having

a plurality of spaced apart support blocks are provided between the base layer and the pair of connector boards in the cargo layer and form a gap therebetween for receiving a lifting member.

20. The method of claim 19, wherein each bracket is triangular with an open interior.

21. The method of claim 20, wherein an upper corner of the inner edge of each end deck board is notched; and wherein an upper tip portion of each bracket is bent into the cutout.

22. The method of claim 21, wherein each upper tip portion is coplanar with an upper surface of each end deck board.

23. The method of claim 19 wherein each nail plate is stamped from a single metal sheet.

24. The method of claim 19, wherein the plurality of projections comprise rounded tips.

25. The method of claim 19, further comprising coupling the pair of end deck boards and the pair of connection boards to the plurality of support blocks using a plurality of fasteners.

26. The method of claim 19, wherein the base layer comprises a pair of spaced apart end deck boards and a pair of spaced apart connector boards orthogonal to the pair of end deck boards, wherein the pair of end deck boards and the pair of connector boards are non-overlapping; and this wooden pallet still contains a plurality of nail boards, and this a plurality of nail boards are coupled between this tip and these a plurality of supporting shoes respectively to the end deck plate body, and each nail board has:

27. The method of claim 26, further comprising a plurality of nail plates coupled between the plurality of support blocks and respective ends of the pair of connection plates of the base layer, each nail plate having