This application relates to modular pallets, such as pallets constructed from recyclable plastic components.
Pallets are commonly used for storing and transporting goods. The vast majority of pallets in commercial use (approximately 95%) are constructed of wood. While wood pallets are in common use they have various shortcomings. Most wood pallets are transported in assembled form and not constructed from modular components. Wood pallets are relatively heavy, typically on the order of approximately 35 to 50 pounds for a standard size unit. This can significantly increase transportation costs. Also, wood pallets are susceptible to bacterial and chemical contamination and insect infestation which make them unsuitable for some applications. They have a limited useful life and are often discarded as trash along with product wrapping materials and the like.
Pallets constructed from plastic are known in the prior art. Plastic pallets are considerably more durable than wood pallets and may outlast wood pallets by four years or more. Plastic pallets effectively resist chemicals, splintering and rot. Other benefits of plastic pallets include fire retardancy, resistance to odour and the ability to be easily sanitized. The primary drawback to widespread adoption of plastic pallets is cost: plastic pallets can cost ten times or more than wood pallets.
Some lightweight plastic pallets are in use that are formed in a unitary mold. Such pallets are expensive to manufacture and ship and cannot be easily disassembled and recycled after their useful life.
Plastic pallets formed from separate modules or components are also known. For example, European patent publication EP 2407391 published 18 Jan. 2012 discloses a modular and multidimensional plastic pallet comprising individual pieces which can be fitted together using a mortise arrangement without the use of welds. This enables individual plastic pieces to be easily dismantled and replaced.
U.S. Pat. No. 5,440,998 dated 15 Aug. 1995 similarly discloses a plastic pallet assembly and method having corrugated deckboards which are designed to be releasably fastened to pallet stringers. Thus the deckboards and stringers are not integrally connected together after assembly.
U.S. Pat. No. 3,878,796 dated 22 Apr. 1975 discloses a knock-down plastic pallet assembly comprising stringers and deck boards which are held in an interlocked relationship by an arrangement of notches and shoulders.
The modular pallets known in the prior art suffer from the disadvantage that they are relatively expensive to manufacture and ship, are formed from an excessive number or size of plastic components, are not readily recyclable and/or are optimized for easy disassembly rather than superior durability and load-carrying characteristics. The need has therefore arisen for improved modular pallets capable of overcoming at least some of the limitations of the prior art.
The foregoing examples of the related art and limitations related thereto are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification and a study of the drawings.
The following embodiments and aspects thereof are described and illustrated in conjunction with systems, tools and methods which are meant to be exemplary and illustrative, not limiting in scope. In various embodiments, one or more of the above-described problems have been reduced or eliminated, while other embodiments are directed to other improvements.
In one aspect there is provided a modular pallet comprising a plurality of elongated frame members arranged in spaced-apart relation, wherein each of the frame members comprises an upper surface and a lower surface and wherein at least the upper surface has a plurality of spaced-apart channels formed therein; and a plurality of elongated deck members positionable in the channels for coupling the frame members together. In some embodiments each frame member may comprise a unitary stringer. In other embodiments each frame member may comprise a block pallet subassembly comprising a plurality of blocks and at least one block connector. In some embodiments a deck support panel comprising the spaced-apart channels may be positioned on each block pallet subassembly.
In another aspect a kit for forming a pallet is provided comprising a plurality of elongated frame members positionable in spaced-apart relation each comprising an upper surface and a lower surface, wherein at least the upper surface has a plurality of spaced-apart channels formed therein; and a plurality of elongated deck members positionable within the channels for coupling the frame members together.
In another aspect a method of forming a pallet is provided comprising providing a kit as described above; arranging the frame members in spaced-apart relation such that the channels in corresponding ones of the frame members are aligned; inserting the deck members within the channels such that the deck members extend to connect the frame members together; and integrally connecting the deck members to the frame members. In some embodiments the frame members and the deck members are formed from plastic and the connecting comprises heat welding the deck members to the frame members.
In addition to the exemplary aspects and embodiments described above, further aspects and embodiments will become apparent by reference to the drawings and by study of the following detailed descriptions.
Exemplary embodiments are illustrated in referenced figures of the drawings. It is intended that the embodiments and figures disclosed herein are to be considered illustrative rather than restrictive.
Throughout the following description specific details are set forth in order to provide a more thorough understanding to persons skilled in the art. However, well known elements may not have been shown or described in detail to avoid unnecessarily obscuring the disclosure. Accordingly, the description and drawings are to be regarded in an illustrative, rather than a restrictive, sense.
This application relates to a pallet 10 formed from modular components. In some embodiments pallet 10 is assembled from a plurality of frame members 12 and a plurality of deck members 14. With reference to
In embodiments configured as a stringer pallet 10 each frame member 12 may comprise a unitary stringer 20 (
In the embodiment of
In the embodiment of
As best shown in
In some embodiments the size of channels 28 may vary to accommodate deck members 14 of different sizes. For example, comparatively larger channels 28 may be formed at end portions of each stringer 12 to receive comparatively larger, lead deck members 14. In other embodiments the size of channels 28 may be uniform for receiving deck members 14 of correspondingly uniform size.
The spacing between channels 28 may be uniform or may vary. In the illustrated embodiment of
In other embodiments channels 28 may be uniformly spaced along the length of each stringer 20 such that deck members 14 are also uniformly spaced.
As is apparent from the embodiment of
In some embodiments the width of channels 28 and the corresponding width of deck members 14 may vary between about ¼ inches and about 10 inches. In particular embodiments the width of channels 28 and deck members 14 may be less than about 10 inches, or 8 inches, or 6 inches, or 4 inches, or 2 inches, or 1 inch.
The weight of pallet 10 may vary depending on the overall dimensions of pallet 10 and the size and number of deck members 14. In some embodiments the overall weight of pallet 10 may be less than about 50 pounds, or 40 pounds, or 30 pounds, or 25 pounds, or 20 pounds, or 15 pounds, or 10 pounds.
In one exemplary embodiment shown in
Thus, in this example upper surfaces 22 of stringers 20 and outer surfaces 34 of deck members 14 make up approximately 32% of the overall surface area of upper deck surface 16. Similarly, in this example lower surfaces 24 of stringers 12 and outer surfaces 34 of deck members 14 make up approximately 20% of the overall surface area of lower deck surface 18.
For comparison purposes, a conventional wood pallet which is 48×40 inches in size comprises three stringers and, on its uppers deck surface, six 40×4 inch deck members and two 40×6 inch deck members. On its lower surface such a conventional wood pallet comprises four 40×4 inch deck members and two 40×6 inch deck members. Thus, in such a conventional wood pallet the load-supporting surfaces of the upper deck members comprise 1440 square inches or approximately 75% of the overall surface area of the upper deck surface. The load-supporting surfaces of the lower deck members comprise 1120 square inches or approximately 58% of the overall surface area of the lower deck surface. As will be appreciated by a person skilled in the art, in a conventional wood pallet the deck members are mounted overlying the outer surfaces of the stringers and hence the outer surfaces of the stringers do not form part of the deck support surface in a conventional pallet.
In some embodiments pallet 10 may be configured so that deck members 14 comprise less than about 60% of the overall surface area of deck surface 16. In other particular embodiments deck members 14 may comprise less than about 50% or 35% of the overall surface area of deck surface 16.
Unlike some prior art plastic pallets, in some embodiments pallet 10 generally resembles conventional wood pallets in size and appearance which may aid in its commercial adoption. However, it is apparent from the foregoing examples that in the exemplary embodiment pallet 10 may be constructed from considerably less material (less than half) than a conventional wood pallet. This may result in a pallet 10 which is considerably lighter and hence easier and less expensive to handle than a conventional wood pallet while maintaining sufficient torsional rigidity and strength characteristics to support comparable static and dynamic loads. Pallet 10 of this example also uses considerably less material than many prior art plastic pallets, similarly resulting in commercially significant cost savings.
In use, pallet 10 of the embodiment of
As shown best in
When stringer members 48 are positioned within slots 50 and are secured in place, for example by heat welding or adhesives, they define an upper and/or lower planar surface for receiving a deck support panel 42 or for supporting pallet 10 on a support surface. Stringer members 48 also provide each block pallet subassembly 40 and hence each frame member 12 with torsional rigidity.
In some embodiments a deck support panel 42 may be positioned on each block pallet subassembly 40 (e.g.
Each deck support panel 42 may be connectable to an upper portion of a respective block pallet subassembly 40 to form a portion of upper deck surface 16 or may be connectable to a lower portion of a respective block pallet subassembly 40 to form a portion of lower deck surface 18. Each deck support panel 42 is connectable to a corresponding block pallet subassembly 40 by any suitable means, such as heat welding or adhesives. In some embodiments each deck support panel 42 may serve a dual function to support deck members 14 and also to couple blocks 44 together. That is, each deck support panel 42 may be connected directly to blocks 44 (e.g.
As described above, in some embodiments slots 50 formed in blocks 44 could be formed in one surface of block 44 (
In use, modular pallet 10 of the embodiments of
As described above, in other embodiments a plurality of block pallet subassemblies 40 could be used in association with continuous panels 52 or other modular pallet structures.
In some embodiments pallet 10 may be shipped to an assembly site in a disassembled state, e.g. with deck members 14 and stringers 20 packaged as separate pieces of a kit; and/or deck members 14, deck support panels 42, blocks 44 and stringer members 48 packaged as separate pieces of a kit. This enables the component parts of modular pallet 10 to be shipped more compactly and economically than unitary or pre-assembled pallets 10. At the assembly site, which could be at or close to the site of use, pallets 10 could then be easily assembled as described above. In some embodiments deck members 14 and stringer members 48 could be the same shape and diameter and could be cut to size as necessary at the assembly site.
As indicated above, in some embodiments pallet 10 is constructed from plastic. For example deck members 14, stringers 20, deck support panels 42, blocks 44 and/or stringer members 48 could be constructed by means of plastic injection moulding, pressure moulding or extrusion.
As discussed above, plastic pallets 10 may have a considerably longer useful life than conventional wood pallets. After use, the component parts of pallet 10 may be recycled. Pallet 10 may be constructed from readily recyclable plastic. Examples of readily recyclable plastics include polyethylene terephthalate (PET), high density polyethylene (HDPE), polyvinyl chloride (PVC), low density polyethylene (LDPE), polypropylene (PP), and polystyrene (PS). In some embodiments pallets 10 may be constructed from combinations or mixtures of different compatible plastics.
In some embodiments pallet 10 may be constructed from doped plastic. By way of example the plastic may be doped with materials such as wood flour, chalk, talc, clay, ground-up coconut husks, carbon fibres, metal fibres and calcium carbonate. The plastic used to construct pallet 10 may also include additives to alter or enhance the colour, fragrance, fire retardation or other qualities of pallet 10.
While a number of exemplary aspects and embodiments have been discussed above, those of skill in the art will recognize certain modifications, permutations, additions and sub-combinations thereof. It is therefore intended that the following appended claims and claims hereafter introduced are interpreted to include all such modifications, permutations, additions and sub-combinations as are consistent with the broadest interpretation of the specification as a whole.
This application is a continuation of U.S. patent application Ser. No. 16/855,611 filed 22 Apr. 2020, which is a continuation of U.S. patent application Ser. No. 15/719,339 filed 28 Sep. 2017 and now issued as U.S. Pat. No. 10,647,470. Each of the above-referenced patent applications and patent is hereby incorporated by reference herein in its entirety.
Number | Date | Country | |
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Parent | 16855611 | Apr 2020 | US |
Child | 18202214 | US | |
Parent | 15719339 | Sep 2017 | US |
Child | 16855611 | US |