The present invention generally relates to a pallet. In particular, the present invention relates to a plastic pallet having an alternating pattern of raised and recessed areas forming the deck of the pallet.
Pallets are used in a variety of industries and generally act as platforms that facilitate the transport of bulky or heavy materials. The most common pallet is a wooden pallet having a deck constructed of a plurality of slats. While wooden pallets enjoy widespread use, they have some disadvantages including their susceptibility to insect infestation, warping, and rotting. Consequently, wooden pallets must be repeatedly treated resulting in substantial maintenance costs.
As a solution to these problems, plastic pallets have been developed. As will be appreciated, plastic pallets may be more expensive than their wooden counterparts. But, in general, they weather better than wooden pallets and are not susceptible to insect infestation allowing continued use of the pallet without further treatment.
While plastic pallets have generally improved upon their wooden counterparts, current pallet designs still have some drawbacks. In particular, to obtain the necessary strength for supporting large loads, these pallets may require a great amount of plastic material and are quite heavy. In particular, compression molded plastic pallets may have a weight of at least 30 pounds, and injection molded pallets may have a weight of about 16 to 17 pounds The present designs include a number of downwardly extending legs that extend from a deck made of a plurality of thin slats that are arranged in a screen or lattice-like fashion with a plurality of holes formed therebetween. These slats generally are thin members that span the entire width of the pallet between the legs. These members are particularly susceptible to bending and buckling when subjected to heavy loads. Consequently, it is desirable to design a pallet with an improved deck that is less susceptible to buckling.
Moreover, because of their cost, existing pallets often must be returned after a shipment is completed. Consequently, additional expense is incurred to ship the empty pallets back to the user. A lighter weight pallet would be beneficial in terms of the cost of shipping the pallets back after use or may be effective in one-way shipments, where the pallet is not returned.
It is an object of the present invention to provide an improved pallet which is less costly and which includes a deck that is less susceptible to buckling.
This and other objects of the present invention, as well as the advantages thereof over existing prior art forms, which will become apparent from the description to follow, are accomplished by the improvements hereinafter described and claimed.
In general, a pallet made in accordance with the present invention includes a plurality of legs extending downwardly from a deck that includes raised and recessed areas. The raised areas lie in a substantially horizontal top plane and the recessed areas lie in a substantially horizontal bottom plane. The raised and recessed areas are interconnected to each other by an upstanding wall.
The present invention further provides a pallet including a deck having a plurality of raised and recessed areas that respectively lie in a substantially horizontal top plane and a substantially horizontal bottom plane. The top and bottom planes are vertically spaced from each other. The raised and recessed areas include planar webs having a polygonal shape that respectively lie in the top and bottom planes and are interconnected to each other by an upstanding wall. The raised and recessed areas are arranged on the deck in an alternating pattern. The pallet further includes a plurality of legs extending downward from the deck below the bottom plane to define a gap beneath the bottom plane and between the legs.
A preferred exemplary pallet according to the concepts of the present invention is shown by way of example in the accompanying drawings without attempting to show all the various forms and modifications in which the invention might be embodied, the invention being measured by the appended claims and not by the details of the specification.
A pallet according to the concepts of the present invention is generally indicated by the numeral 10 in the accompanying drawings. Pallet 10 generally includes a plurality of legs 12 and a deck 14. As best shown in
The recessed and raised areas 16, 18 may be arranged in a pattern, such as the alternating raised and recessed pattern shown. It will be appreciated that the pattern does not have to cover the entire surface of the deck 14 and may be truncated at the periphery of the deck 14 due to size limitations, as best seen, for example in
To prevent water from collecting on the deck 14, each web 20 may be provided with at least one drainage hole 28, as shown. To facilitate handling of the pallet 10, the deck 14 may be provided with one or more holds 24. It will be appreciated that a hold 24 may be any surface that facilitates the grasping of the pallet 10 by a user including, for example, the oval shaped holes shown formed in recessed areas 16. It will further be appreciated that the holds 24 may be placed at any location on the deck 14. In the example shown, holds 24 are located in the recessed areas 16 near the periphery of the deck 14 and on either side of a centrally formed trench 26, described more completely below.
As best shown in
To strengthen the deck 14 at the ends of the trench 26, a number of reinforcing folds 27 may be formed at either end of the trench 26 at the outer wall 32 of the deck 14. These folds 27 have the effect of increasing the moment of inertia of the wall 32 at the ends of the trench 26 to help it resist buckling. Similarly, reinforcing columns 29 may extend upwardly from the base 25 of the trench 26 along its length. In the example shown, columns 29 are provided adjacent to legs 12 formed within trench 26 and extend upwardly from the base 25 of the trench 26 adjacent to a recessed portion 16, as best shown in
As depicted in the given example, the spacers 31 may be placed adjacent to recessed area 16 to further strengthen the deck 14 and provide continuity within the alternating pattern of recessed and raised areas 16, 18. In terms of manufacturing, trench 26 facilitates outward flow of material from the center in a compression molding process. It will be appreciated that the trench 26 is not a necessary part of the design and the alternating pattern of recessed and raised areas 16, 18 may continue in place of the trench. In such an example, the pattern of such areas 16, 18 would cover the entire deck 14.
A rim 30 may be formed at the periphery 24 of the deck 14 and lie in the top plane T (
As mentioned above, the deck 14 is supported on legs 12. The legs 12 may be of generally any form and preferably extend downwardly from the deck 14 an extent sufficient to create a gap 36 between the bottom surface 38 of the deck 14 and the supporting surface on which pallet 10 stands. This facilitates movement of pallet 10 by a forklift or similar device. With this in mind, legs 12 may be arranged to define a central space into which the forks of a forklift may be inserted. In the example shown, three rows (12A, 12B, 12C) of three legs 12 are provided with fork receiving gaps 36 formed on either side of the central row (12C) and central column (12Cā²) formed by the legs 12. In the example shown, the deck 14 has a square shape at its periphery 24 and, thus, the legs 12 are evenly spaced from each other in both the lateral and longitudinal directions. It will be appreciated, however, that other deck shapes may be used causing the spacing and number of legs 12 to vary from the depicted example.
With reference to
In the example shown, legs 12 are somewhat rectangular in shape having, as indicated in
As best shown in
The pallet 10 may be formed of any polymeric material including high density polyethylene. The pallet 10 may be constructed as a unitary structure, as shown, or assembled from separate components, for example, legs 12 may be attached to a separately formed deck 14. The pallet 10 may thus be formed with any molding or similar process used to manufacture polymeric products. In the example shown, pallet 10 is constructed in a compression molding process. As will be understood by one of ordinary skill, the compression molding process includes providing a pair of mold halves with a billet of material placed within the mold before the halves are squeezed together to cause the billet to flow throughout the mold. As will be appreciated, with fewer corners and sides to work with, the material is better able to flow and form the desired shape. Therefore, while any shaped web 20 may be used, the triangular web shapes shown in the drawings were chosen because it has the fewest sides and corners of a regular geometric shape. Thus, the use of the triangular web 20 is believed to facilitate the flow of material within the mold. This shape, however, is not limiting.
The resulting pallet 10 with raised and recessed webs 20 interconnected by a network of upstanding walls 22 results in a lightweight pallet 10 having a load capacity commensurate with that of existing pallets. For example, the depicted pallet 10 has been found capable of supporting loads in excess of 2,000 pounds The increased strength provided by the alternating raised and recessed deck design allows the pallet 10 to be constructed with less material resulting in a lighter pallet. For example, a pallet 10 similar to that depicted has a weight of about 14.5 pounds This is less than half of the weight of a comparable compression molded plastic pallet existing in the art and is even lighter than injected molded pallets. As will be appreciated, any weight savings becomes extremely significant when considering the large number of pallets used in transporting cargo on trailers, airplanes, and boats. Further, the lightweight pallet 10 is easier to handle. The savings in material and use of a compression molded product allows the pallet 10 to be constructed at extremely low cost. This in connection with the weight savings makes the pallet 10 attractive for one way use applications. By one way use applications, it will be understood that the pallet 10 is shipped to a destination and then not returned. The cost of existing pallets has made this practice undesirable and typically pallets must be returned. As will be appreciated, some efficiency in shipping is lost by shipping back the empty pallets.
In light of the foregoing, it should thus be evident that a pallet constructed as described herein substantially improves the art and otherwise accomplishes the objects of the present invention.
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3603272 | Ditges | Sep 1971 | A |
3640229 | Bell | Feb 1972 | A |
4369716 | Munk et al. | Jan 1983 | A |
4809618 | Bell | Mar 1989 | A |
5566624 | Brown et al. | Oct 1996 | A |
5964162 | Chuan-Jen | Oct 1999 | A |
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6807911 | Carson et al. | Oct 2004 | B1 |