Rackable composite shipping pallet for transporting and storing loads
A rackable pallet is disclosed that has a load bearing deck, a plurality of cross beams, and a plurality of removable base supports connected approximately perpendicular to the cross beams, and is made of a polymer. One disclosed pallet is open from the bottom and particularly suited for use in large automated warehouses, where machinery lifts and moves pallets by remote control. In one embodiment the pallet comprises a support structure that comprises a plurality of cross beams and a plurality of base supports connected to the cross beams. The deck and the cross beams typically define a single, injection-molded piece of polymer material. The base supports may be removable for repair or replacement. In one embodiment the load bearing deck has a plurality of domes in an array that provide high strength, stiffness, and rigidity.
This is a continuation-in-part of application Ser. No. 10/364,867, filed Feb. 10, 2003, entitled LOAD BEARING STRUCTURE FOR SHIPPING PALLET, now U.S. Pat. No. 6,857,377 issued Feb. 22, 2005, which is a continuation-in-part of application Ser. No. 09/978,861, filed Oct. 16, 2001 entitled LOAD BEARING STRUCTURE FOR SHIPPING PALLET, both of which are incorporated by reference herein in their entirety.
BACKGROUND OF THE INVENTION1. Field of the Invention
The present invention generally relates to shipping pallets. More specifically, the invention is directed toward a pallet comprising a load bearing deck and an undercarriage for receiving a forklift, palletjack, hand truck or other automated machinery.
2. Description of Related Art
Pallets are widely used today to efficiently transport nearly everything worldwide, such as food, beverage, and most every manufactured item or goods. Generally shipping pallets are portable platforms upon which load is first placed, and then moved by machinery (e.g., a forklift) from place to place for storage and/or transport. A pallet typically has slats and posts arranged to provide a top surface and open access underneath for a forklift-type device. Bottom slats may also be added to provide for transport on conveyer belts, for use in automated machinery, and to add strength, stiffness, and rigidity to the pallet. Currently, the world market exceeds 1.5 billion new wood pallets sold annually with the United States alone accounting for half a billion new wood pallet sales, and predictions are that sales for new pallets will increase. In addition, around 200 million recyled or repaired wood pallets are sold. It is estimated that there are 2 billion pallets in circulation in the U.S. today, with wood pallets making up about 90% of the total market. The share of plastic pallets is about 3%, and expected to grow.
Conventional shipping pallets are usually constructed of wood or wood products with numerous associated problems. Wood pallets are heavy, expensive (especially those designed for four-way entry for a forklift) and subject to insect infestation. Some shipping pallets are constructed from alternative materials, but no matter what construction material is used, conventional shipping pallets suffer from one or more significant problems: limited strength, especially over extended periods of time, cumbersome weight, flexibility and bendability, high expense, limited usability, complex production requirements, ecological unacceptability, and inability to reuse or recycle.
U.S. Pat. No. 5,816,172 to Carter discloses a pallet constructed from paperboard. The pallet includes a plurality of elongated runners constructed from cylindrical cores and a deck formed from a number of elongated arcuate segments of the cylindrical cores.
U.S. Pat. No. 6,041,719 to Vidal et al. discloses a pallet with an upper tray for receiving a load and a lower face that has reinforcing and supporting elements attached thereto. The reinforcing and supporting elements are V- or U-shaped elements and extend longitudinally and transversely along the lower face.
U.S. Pat. No. 6,386,118 to Bendit et al discloses a one-piece hollow, continuous pallet that has a deck and underside. The underside includes structural features that function in conjunction with the deck for support and reinforcement when a load is placed on the pallet. The structural features include an arched bottom recess, side impact depressions, and “kiss-off” structures. The pallet may be made using rotational molding processes.
SUMMARY OF THE INVENTIONA pallet made of a polymer is disclosed that has a load bearing deck for receiving a load, a plurality of cross beams, and a plurality of base supports connected approximately perpendicular to the cross beams, and is made of a polymer. One disclosed pallet has a rackable configuration particularly suitable for use in large automated warehouses, where machinery lifts and moves pallets by remote control.
In one embodiment the rackable pallet for holding and transporting materials comprises a rigid deck that has an upper and a lower surface and a plurality of arch elements configured with their top peaks proximate to the upper surface, the deck including a plurality of adjacent arch elements situated in an intersecting configuration such that downward forces from a load applied to the upper surface of the deck are distributed from the top of the arches downwardly through each of the arch elements and laterally towards adjacent arch elements, such that forces from adjacent arch elements intersect each other to provide lateral compressive forces to strengthen the deck.
A support structure extends from the lower surface of the deck which supports the deck, allows transport by machinery, and provides a resting surface for the pallet. The support structure comprises a plurality of cross beams connected to the lower surface of the deck, the cross beams arranged approximately parallel to each other, each of the cross beams comprising a plurality of downwardly-facing openings. The cross beams may comprise a plurality of transverse and longitudinal ribs arranged in an intersecting configuration. The support structure also includes a plurality of base supports connected to the cross beams, the cross beams having an upwardly-extending section that has a configuration for engaging with the openings in the cross beams. The base supports are arranged approximately parallel to each other and approximately perpendicular to the cross beams. The deck and the cross beams typically define a single, injection-molded piece of polymer material.
Advantageously, the base supports may be removably engaged with the cross beams, which allows the base supports to be removed for repair, replacement, and/or to use the pallet without the base supports, if feasible. To facilitate replacements and keep costs down, each of the plurality of base supports may be substantially identical and thereby interchangeable. The plurality of base supports, which may molded of a polymer, define a surface appropriate for the surface it is resting against. For example the base supports may define an approximately flat bottom surface for resting on a flat surface.
In one embodiment, that pallet has three cross beams and three intersecting base supports that intersect the cross beams at approximately 90°.
The cross beams and the base supports are configured to define spacing to receive at least one of a forklift, pallet jack, hand truck, and automated lifting machinery. The spacing may be different on adjoining sides: one side may be open on the bottom, which provides access by the automated lifting machinery in addition to forklifts, and the other side may be closed at the bottom by the base support, thereby preventing access by automated machinery, while still allowing access by forklifts.
In one embodiment the shipping pallet comprises a load bearing deck that defines an upper surface for receiving the load and a lower surface opposite the upper surface. In this embodiment the load bearing deck comprises a plurality of domes, wherein each dome is defined by an apex located proximate to the upper surface and a plurality of legs extending from the apex and ending at the lower surface. The domes are arranged in an array including a plurality of adjacent domes that provide high strength, stiffness, and rigidity, which makes the pallet suitable for long-term and heavyweight use. In some embodiments the domes have an open structure that reduces material requirements, thereby allowing the pallet to be manufactured at lower weight and lower cost. The pallet may be manufactured of a polymer (e.g., plastics, resin); thus the pallet may be recyclable, ecologically acceptable, and resistant to insect infestation. Additionally, the pallet may be designed in any appropriate manner for four-way entry of a forklift, palletjack, or other automated machinery, making the pallet more versatile than many conventional pallets.
The array of domes may be defined by a plurality of dome rows that extend in at least two directions and intersect each other at a non-zero angle to form a pattern. In one embodiment, the array pattern may comprise a honeycomb such that any three adjacent dome apexes approximately define an equilateral triangle. In an alternative embodiment, the array pattern may comprise a grid such that four adjacent dome apexes approximately define a square.
In some embodiments, the domes may comprise an open dome structure; that is, the domes may be defined by a plurality of arches having apexes that define the dome apex, and two legs extending from each of the arch apexes that define the dome legs. Openings are defined between the dome legs thereby forming the open dome structure. In alternative embodiments, the plurality of domes may comprise a closed dome structure; that is, the domes may be defined by a surface, which may be thought of as an infinite number of arches angularly rotated through 360° with no openings therebetween.
The array of open domes may be defined by a plurality of intersecting arch rows with each arch row comprising a plurality of adjacent arches in some embodiments. In some embodiments, the domes may define a substantially circular curvature, and the distance between two adjacent dome apexes may be approximately equal to two times the radius of curvature. In other embodiments, the radius of curvature may be different and/or the domes may comprise a non-circular shape.
The domes may comprise a partial arch configuration in some embodiments; that is, the arches that form the dome may comprise a partial arch configuration defined by the legs ending in a substantially non-vertical orientation.
The deck may comprise structural fill that extends from and between the legs of at least some adjacent domes and provides continuity and additional structure to the load bearing deck. Circular hoops may be provided where the domes end at the lower surface of the load bearing deck. Webbing may be provided between the circular hoops on the lower surface of the deck to provide continuity and structure to the lower surface of the deck.
In some embodiments, the upper surface of the load bearing deck defines an approximately flat plane, and the dome apexes may be configured to extend above the flat plane such that the upper surface of the deck is uneven.
BRIEF DESCRIPTION OF THE DRAWINGSFor a more complete understanding of this invention, reference is now made to the following detailed description of the embodiments as illustrated in the accompanying drawings, wherein:
This invention is described in the following description with reference to the figures, in which like numbers represent the same or similar elements.
GLOSSARY OF TERMS AND ACRONYMSThe following terms are used throughout the detailed description:
- arch A structure that begins at an apex has two legs that extend downwardly from the apex toward their lower ends. An arch transmits an applied load in two directions substantially laterally through the legs of the arch. A “full” arch extends fully from the apex through to a point wherein both legs are substantially vertically oriented at their lower ends. A “partial” arch has legs that have been truncated short of a full arch, such that the legs are non-vertically oriented at their lower ends.
- arch row A row comprising a plurality of arches.
- dome A three-dimensional element defined by a plurality of arches angularly arranged at varying degrees about a vertical axis extending through the apex of the arches such that the apexes of the plurality of arches coincide with each other at their vertical axes. An “open” dome is defined by a finite number of arches angularly arranged at differing degrees less than 360°, which provide open areas between the legs of the arches such that an applied load is transmitted laterally in a finite number of directions defined by the legs of the finite number of arches. For example, three arches may be arranged at equal 60° intervals about the vertical axis; or four arch rows may be arranged at 30°-60°-60°-30° intervals. A “closed” dome is a surface rather than discrete arches, which may be thought of as an infinite number of partial arches rotated 360° about the vertical axis such that an applied load is transmitted in an infinite number of directions.
- deck The upper load bearing structure of a pallet on which a load is placed.
- undercarriage The supporting structure of a pallet below the deck for supporting the deck and load.
Overview
In the figures, like reference numbers indicate the same elements throughout. The figures generally show various views and elements of one embodiment of a shipping pallet comprising a deck that has a load-bearing structure for securely supporting heavy loads over extended time periods, and an undercarriage for supporting the deck and designed to allow four-way entry for a forklift, palletjack, hand truck or other automated machinery. The design of the load bearing deck includes a plurality of domes designed and situated adjacent to each other to create increased strength and durability to the pallet through the distribution of forces, as will be described herein.
In one embodiment, the pallet comprises a deck, a cross beam support structure underneath the deck and a plurality of base supports connected to the cross beams in an intersecting configuration.
Manufacture
In one embodiment, the deck and underlying beam support structure are injection-molded as one unitary piece from a polymer (e.g., a polyethylene material), however a variety of materials and manufacturing processes can be used. For example, polyolefin, such as polyurethane, polypropylene, polyvinyl-chloride and polycarbonates, as well as composites thereof, are known in the art and can be used to provide a desired strength, stiffness, rigidity, weight, impact resistance, and durability.
In some embodiments, the pallet is specifically designed for manufacture by molding processes, that is, the molding process fully forms and easily releases the end product pallet such that no post-molding steps or processes are necessary. For example, injection molding is a method of forming articles by heating the molding material until it can flow, and then injecting it into a mold at high pressure (e.g., 1500 PSI). The mold is typically two pieces that together form a cavity between which the molding material forms its shape. Thus, by designing a pallet that allows the two pieces of the mold to pull away from the top and bottom of the pallet, efficient and low cost manufacturing may be obtained.
The pallet can be manufactured using a variety of other known processes, such as Reactive Injection Molding (RIM). RIM is a process comprising injecting into a closed mold, under low pressure (e.g. 72 PSI), two or more reactive components mixed within a nozzle just prior to their introduction into the mold. For example, the reaction of a polyol and an isocyanate can be used to form polyurethane.
In some embodiments, the pallet is manufactured as one unitary piece; that is, the deck and the undercarriage are molded together. However, in alternative embodiments, the pallet may be manufactured as two separate pieces; that is, the deck and undercarriage may be molded as separate pieces and then secured together.
The pallet can be manufactured at a relatively low weight: possibly less than 30 pounds, sometimes less that 25 pounds. The low weight pallet design is made possible in part by the design of the load bearing deck including an array of open domes, such as will be described in detail with reference to the figures. That is, the strength provided by the array of open domes enables the use of minimal material with maximum structural integrity. The weight of the pallet may also be determined in part by the material selected for manufacture.
In one example embodiment, the deck of the pallet is a standard size, about 48.0″ by about 40.0″ by about 1.0″, however it should be understood that the deck could be manufactured for a pallet of any size.
In alternative embodiments, the structure of the load bearing deck may be designed for other uses. For example, the load bearing structure could have upwardly extending surfaces that form some or all sides of a container box used for holding and ripening of fruit. In an alternative use, the load bearing structure could be useful for construction purposes such as flooring on the deck of a boat.
In one alternative embodiment, the thickness of the deck may be increased from about 1.0″ to about 1.5″ by increasing the dimensions of the domes, for example. By increasing the thickness of the deck, the rigidity of the pallet may increase, thereby enabling support for heavier loads over longer periods of time.
DETAILED DESCRIPTION
For reference purposes herein, the x-, y- and z-axes of the pallet are defined and shown such that the x- and y-axes extend respectively longitudinally and transversely along the plane of the pallet 10, and the z-axis extends vertically through the pallet.
Arch Design
Reference is now made to
It should be noted that although the theoretical example of
The equilateral arch, for example, begins at an apex and has two legs of constant curvature extending therefrom, wherein the center of radius of the curvature of each of the two legs is located at the end of the other of the legs. Another example of an alternative arch shape is one type of primitive arch that begins at an apex and has two legs that extend in a straight line diagonally downward in opposite directions for a distance and then extend vertically downward. It should be understood that alternative embodiments of the domes of the load bearing deck could be designed using arch shapes other than semi-circular, such as described above.
Under an applied load 110, an arch 108 is always in compression because the structure of the arch reduces the effects of tension on the underside of the arch; that is, the force 112 is transmitted substantially laterally along the legs 114 of the arches 108 toward their lower ends 116, thereby transmitting a significant portion of the load substantially laterally outwardly from the arch.
The partial arches 122 shown in
The partial arches in one embodiment are designed by overlapping full arches (shown in
It should be noted that the center-to-center distance, the radius of curvature, the line at which the arches are truncated to form partial arches, and the theoretical or actual intersection point of the compressive forces of adjacent arches (such as described with reference to
As will be described in detail with reference to FIGS. 6 to 8C, the arch rows including the design of partial arches discussed with reference to
The arches 122 are situated such that the load 110 applied substantially to the arch apexes 121 transmits forces 128 laterally toward an intersection point 129 between adjacent partial arches 122, thereby producing compressive forces that counteract each other.
Thus, when a load bearing deck is designed with a plurality of domes 106 utilizing the design of intersecting partial arches such as described herein, the forces applied by a load to the load bearing deck are not only transmitted substantially laterally, but the tensile stresses, induced by a bending moment imposed upon on the structure from the applied load, are at least partially canceled by virtue of the forces between adjacent domes intersecting each other, which places the load bearing deck into compression and creates at least partially offsetting compressive forces within and between the domes.
Load Bearing Structure
The array of domes comprises a plurality of dome rows such as will be described elsewhere in more detail with reference to
In some embodiments, beams 150 extend through the middles of at least some of the dome rows. The beams may have a vertical height substantially equal to the height of the deck, a horizontal length that extends part or all of the length of a dome row (such as will be described with reference to
In some embodiments, structural fill 152 extends at least partially between some of the adjacent domes and fills in space between adjacent legs of adjacent domes. The structural fill 152 is formed of molded material in the injection-molding process, and provides strength to the load bearing deck and aids in the injection-molding process by providing a path for material flow. In alternative embodiments, structural fill may be added or omitted as desired to increase rigidity or decrease weight, for example.
In some embodiments, ribs 158 may be provided on the lower surface of the deck, described elsewhere in detail such as with reference to
In one aspect of the embodiment of
In the embodiment of
One advantage of the honeycomb-like pattern is that it is resistant to twisting because of interference caused by the off-setting structure of the domes 106. Another advantage of the honeycomb-like pattern is that it enables more efficient use of material, that is, a greater number of domes will fit into a specified area, compared to other patterns (e.g. rows at 90°), thereby increasing the strength of the load bearing deck and thus the ability to hold heavy loads over extended periods of time.
In alternative embodiments the rows of domes could cross each other at alternative angles such as 30°, 45° and 90°, thereby creating alternative patterns. For example, dome rows may be arranged such that they extend in only two directions that intersect each other at a 90° angle, thereby creating a grid pattern. The grid pattern may be defined by squares formed between the apexes of four adjacent domes.
In another aspect,
Each arch row 131 comprises a plurality of adjacent arches 122, such as described in more detail with reference to
Thus, in the embodiment shown in
In this aspect of the invention, the arch rows 131a to 131d may be designed as described with reference to
In some alternative embodiments, the plurality of arch rows may intersect each other at alternative angles, and thus may comprise sets of parallel arch rows that extend in only two or three directions. For example: a first, second, and third set of parallel rows that extend in a first direction, second and third set of directions respectively, wherein the second direction intersects the first direction at an angle of about 60° and the third direction intersects the first direction at an angle of about 120° (not shown); and a first and second set of parallel rows that extend in first and second directions, wherein the second direction intersects the first direction at an angle of about 90° (not shown).
In some embodiments, at least some of the arch rows (e.g., 131c) are replaced by beams 150 that extend through the entire deck, as described in more detail with reference to
It should be noted that
In yet another alternative embodiment, the areas 160 from which the posts extend are designed for nesting with another pallet; that is, the areas 160 may comprise apertures designed to receive the posts of another pallet such that a plurality of a pallets can nest within one another.
An open dome structure is shown in one embodiment in
It should be noted that in the illustrated embodiment, such as described elsewhere in more detail with reference to
The open dome structure provides increased strength, as compared to an arch that transmits forces in only two directions (such as shown in FIGS. 2 to 5). In other words, in an open dome structure, the forces 112 are spread in many directions (e.g. at least six directions as shown in the embodiment of
As shown in
In an alternative embodiment, one or more of the domes 106 may comprise a fully closed dome structure; that is, the dome may be defined by a surface rather than discrete arches. The surface of the closed dome may be thought of as an infinite number of arches angularly rotated through 360°; i.e., closed domes do not have openings. In this alternative embodiment, some or all of the domes of the load bearing deck could be closed domes while others remain open.
The hoops 142 extend around the lower end 144 of each dome and may provide natural hoop strength to the load bearing deck 100 in one embodiment. The hoops 142 of adjacent domes are connected to each other by webbing 148 that provides continuity between the adjacent domes 106 and forms a part of the lower surface 104 of the load bearing deck 100.
Although the hoops 142 are shown as circular in shape, they may be shaped as diamonds, tringles, ovals or other shapes in alternative embodiments. It should be noted that the diameter of the hoop will vary as the dimensions and design of the domes are altered. For example, if the deck is made narrower and all else remains the same, then the hoop diameter will be smaller.
Dome apexes 134 extend above the flat plane of the deck 146 (defined by the outer edges of the upper surface of the deck as shown in
The structural fill 152 extends between adjacent dome legs 140 and may extend above the flat plane of the deck 146 by a predetermined distance 154, which is typically less than the distance 156 that the apexes 134 extend above the plane of the deck (e.g. a difference of approximately 0.025″ in one embodiment). As a result, the raised dome apexes 134 provide friction on the upper surface of the deck 102, which is useful to prevent the load from sliding off in transit.
In some embodiments, the structural fill 152 may comprise different thicknesses in different areas of the pallet; that is, the predetermined distance 154 may not be constant in all embodiments of the pallet such as shown in
It should be noted that webbing 148 and ribs 158 are shown here, however they are described elsewhere in detail such as with reference to
In one embodiment of the deck, the dimensions of the domes 106 include a radius of about 1.55″, a wall thickness of about 0.2″, and a center-to-center distance between adjacent apexes of about 3.0″. The webbing 148 is dimensioned considering necessary strength and weight, for example a thickness of about 0.2″. The total thickness of the deck therefore, taking into consideration the partial arch design of the domes, is approximately 1.065″ in one embodiment, however the dimensions may be increased or decreased as desired.
In an alternative embodiment, the thickness of the deck may be increased from the example embodiment above, such as by about 25% for example by increasing the inner radius, the outer radius and/or the center-to-center distance between the dome apexes. By increasing the thickness of the deck, the rigidity and load bearing strength of the deck will increase. Other alternative dimensions may be applied to the pallet in order to increase strength, decrease weight, or otherwise alter desired properties of the shipping pallet.
Upper and Lower Camber
In one embodiment of the pallet, the deck 100 is formed to include an overall camber on its upper and lower surfaces (not shown). An upper camber is defined by a slightly upward curved overall arch toward the center of the deck.
In one embodiment, the curvature of the upper camber is provided by the positioning of the domes above the flat plane of the deck. In this embodiment, the domes that are located closest to the center of the deck extend above the flat plane of the deck by a distance greater than the domes located farther from the center of the deck, which extend above the flat plane at a progressively lesser distance than those at the center. The upper camber is typically very slight (e.g. in one embodiment, the difference between the distance of the center apex above the plane of the deck and the distance of the outer apexes above the plane of the deck is approximately 0.2″), however in alternative embodiments, the camber may be more or less pronounced.
One advantage of the upper camber as described herein includes decreased slippage of a load on the pallet. That is, when a product is loaded to the upper surface of the deck, the load itself will settle or slightly compress onto and around the individual domes and the camber, thereby increasing the friction and decreasing the possibilty of slippage between the load and the pallet deck.
The pallet may also include a lower camber in some embodiments (not shown). The lower camber in one embodiment may be incorporated into the design of the lower portion of the load bearing deck by decreasing the thickness of the webbing near the center of the pallet (or conversely increasing the thickness away from the center). The lower camber is at its highest point at the center of the deck and curves progressively downward as it extends farther away from the center of the deck, creating a slightly upward curved overall arch toward the center on the lower surface of the deck. The lower camber is typically very slight (e.g. the difference between the thicknesses of the webbing at the center and the thickness of the webbing farthest away from the center is approximately 0.2″ in one embodiment), however in some embodiments, the camber may be more or less pronounced.
In other embodiments, the upper and lower cambers may be designed into the overall mold of the pallet, or may be provided by other processes such as shaping or natural warping incurred in the post-molding process, for example.
Undercarriage Example
Although the beams 150 and ribs 158 extend across the lower surface 104 of the deck, including across and between the domes 106, they do not interfere with the structural function of the domes 106, and in fact provide additional strength, stiffness and stability to the pallet as a whole. Additionally, the beams 150 and ribs 158 may aid in the injection-molding process by providing a path for material flow.
The framework 202 of ribs 158 and beams 150 adds minimal size and weight to the pallet (e.g. extending below the lower surface of the deck with a 0.375″ thickness and 0.2″ width in one embodiment), however the framework may be dimensioned up or down according to desired strength, weight, size, manufacturing, and other requirements.
In some embodiments, the ribs 158 and beams 150 that create the framework 202 have different thicknesses in different locations. The locations, thicknesses, and other parameters may be dimensioned and arranged to meet a variety of structural parameters. In other embodiments, the ribs and/or beams may not be necessary.
In this embodiment of the undercarriage, the plurality of posts 204, 208 extend from the lower surface 104 of the deck to provide support for the deck of the pallet and are situated to define spacing between the posts dimensioned to receive at least one of a forklift, palletjack and hand truck.
In one embodiment, the posts 204, 208 are substantially hollow to minimize the overall pallet weight; stability ribs 206, 210 are formed within the posts to provide stability without significantly increasing the weight. The stability ribs 210 within the central post 208 comprise an arched configuration providing excellent strength and stability. The design of the arched stability ribs 210 could be applied to some or all of the posts 204 in some embodiments.
The configuration of the undercarriage is designed to receive a forklift, palletjack, hand truck or other automated machinery. Because of the arrangement and dimensions of the posts, the undercarriage of the pallet is designed to allow four-way entry for a forklift, palletjack, hand truck or other automated machinery, thus increasing the versatility, usability and flexibility of the pallet. That is, a forklift, palletjack or other automated machinery may enter through any of the four sides.
In an alternative embodiment, the pallet is designed to enable nesting of a plurality of shipping pallets (not shown). In this embodiment, the posts of the pallet are dimensioned to fit within apertures located on the upper surface of the deck and extend through the deck, such as described with reference to
Rackable Pallet with Detachable Base Support Structure
Reference is now made to
In this embodiment, the deck and cross beams can be molded in a single piece, and the base support structures can be attached as appropriate and replaced as needed. Any appropriate polymer may be used, in one embodiment the deck and cross beams are injection-molded in a single mold using primarily HDPE (high density polyethylene). The base supports may also be made by injection-molding using the same material. Generally, any injection-moldable material may be used: “ethylene” or ethylene resin, or injection-molding grade polymer, or injection-molding grade resin.
The pallet can be designed and implemented into any appropriate size. The most common de facto standard in the pallet industry is 48″×40″; in one embodiment the dimensions of the pallet are 48″×40″×5.85″. However, other sizes can be implemented as may be useful or necessary.
Deck
Cross Beams
As shown in
The first cross beam 311, the second cross beam 312, and the third cross beam 313 are arranged parallel to each other with a spacing in-between adequate to receive a forklift. The cross beams in this embodiment comprise two opposing walls 345 and 346, with a plurality of transverse ribs 347 extending between (as shown on the first cross beam 311, for example. A longitudinal rib 348 is also provided in the upper portion of the cross beams (adjacent to the deck). The cross beams may also include one or more rows of domed support structures such as described with reference to the deck.
Each of the cross beams comprises a plurality of openings along their length. For example, as shown in
Base Supports
Reference is now made to
The first base support 321, and second base support 322, and the third base support 323 are arranged to connect across (i.e., perpendicular to) the cross beams. To connect to the cross beams, the base supports include a plurality of sleeves 361 that extend from upwardly-extending post structures 362. At the interface of the sleeve with the post, a shoulder 363 is provided to contact the lower edge surrounding the openings in the cross beams. In this embodiment each base support has a post structure at each end and a post structure in the middle, and a sleeve extends from each. Advantageously in this embodiment all three base supports are identical and therefore interchangeable; although in other embodiments they may be different.
Each sleeve inserts into the corresponding opening in the cross beams; for example the third base support 323 has a sleeve 371 on one end that inserts into the first opening 351, the second base support 322 has a sleeve 372 that inserts into the second opening 352, and the first base support has a sleeve 373 that inserts into the third opening 353. In one embodiment, the sleeves 361 extend upward about 1″ from the shoulders 363. In the illustrated embodiment, the sleeves have an approximately rectangular cross-sectional configuration, however other configurations (e.g. approximately cylindrical) may be implemented.
When all the base supports are connected, they provide structural stability to the pallet, while allowing sufficient space below the pallet to allow automated machinery to lift the pallet from the bottom. Particularly, automated machinery can lift the pallet by placing the lifting device between the base supports, and then pressing the lifting device against the cross beams to lift the pallet.
The base supports are connected to the cross beams by any suitable mechanism, for example a tight clearance between the openings and the sleeves may provide enough friction to securely hold the base supports to the cross beams. Alternatively, a glue may be used, or some welding method may be utilized. Alternatively (or in addition), a hook, or clamp mechanism may also be implemented.
As shown in
The base supports have a bottom surface 385 that has a configuration appropriate to provide a resting surface for the intended storage location. In the shown embodiment, the base supports have a flat bottom which provides a suitable resting surface for the storage racks in common use in large automated warehouses. However, since the base supports are molded, they can formed into any suitable configuration as appropriate.
In this embodiment the base supports 321, 322, and 323 are designed to be insertable and removable with respect to the cross beams. Advantageously, any one of the base supports can be removed for repair, replacement, or even use without the cross beams.
Assembled Pallet
It will be appreciated by those skilled in the art, in view of these teachings, that alternative embodiments may be implemented without deviating from the spirit or scope of the invention. This invention is to be limited only by the following claims, which include all such embodiments and modifications when viewed in conjunction with the above specification and accompanying drawings.
Claims
1. A pallet for holding and transporting materials comprising:
- a rigid deck that has an upper and a lower surface and a plurality of arch elements configured with their top peaks proximate to the upper surface, said deck including a plurality of adjacent arch elements situated in an intersecting configuration such that downward forces from a load applied to the upper surface of said deck are distributed from the top of said arches downwardly through each of said arch elements and laterally towards adjacent arch elements, such that forces from adjacent arch elements intersect each other to provide lateral compressive forces to strengthen said deck; and
- a support structure extending from said lower surface of said deck, comprising: a plurality of cross beams connected to said lower surface of said deck, said cross beams arranged approximately parallel to each other, each of said cross beams comprising a plurality of downwardly-facing openings; and a plurality of base supports connected to said cross beams, said cross beams having an upwardly-extending section that has a configuration for engaging with said openings in said cross beams, said base supports arranged approximately parallel to each other and approximately perpendicular to said cross beams.
2. The pallet of claim 1 wherein said deck and said cross beams define a single, injection-molded piece of polymer material.
3. The pallet of claim 1 wherein said base supports are removably engaged with said cross beams.
4. The pallet of claim 1 wherein each of said plurality of base supports is substantially identical and thereby interchangeable.
5. The pallet of claim 1, wherein said plurality of base supports define an approximately flat bottom surface for resting on a flat surface.
6. The pallet of claim 1 wherein said cross beams comprise a plurality of transverse and longitudinal ribs arranged in an intersecting configuration.
7. The pallet of claim 1 comprising three cross beams and three base supports that intersect said cross beams at approximately 90°.
8. The pallet of claim 1, wherein said cross beams, said base supports are configured to define spacing to receive at least one of a forklift, pallet jack, hand truck, and automated lifting machinery.
9. The pallet of claim 1 wherein said upwardly-extending section of said base supports and the portion of the cross beams surrounding said opening define a plurality of posts, and said plurality of posts are situated to define spacing between said posts dimensioned to receive at least one of a forklift, pallet jack, hand truck, and automated lifting machinery.
10. The pallet of claim 1, wherein said plurality of arch elements comprise a plurality of rows of said arch elements, said plurality of rows extending in at least two directions that cross each other at a non-zero angle.
11. A pallet for supporting a load, comprising:
- a load bearing deck that defines an upper surface for receiving said load and a lower surface opposite said upper surface, said load bearing deck comprising a plurality of domes, each dome defined by an apex located proximate to said upper surface and a plurality of legs extending from said apex and ending at said lower surface, said domes arranged in an array including a plurality of adjacent domes such that a load applied substantially to said dome apexes will be transmitted substantially laterally along said legs to produce intersecting compressive forces between adjacent domes; and
- a support structure extending from said lower surface of said deck, comprising: a plurality of cross beams connected to said lower surface of said deck, said cross beams arranged approximately parallel to each other, each of said cross beams comprising a plurality of downwardly-facing openings; and a plurality of base supports connected to said cross beams, said cross beams having an upwardly-extending section that has a configuration for engaging with said openings in said cross beams, said base supports arranged approximately parallel to each other and approximately perpendicular to said cross beams.
12. The pallet of claim 11 wherein said deck and said cross beams define a single, injection-molded piece of polymer material.
13. The pallet of claim 11 wherein said base supports are removably engaged with said cross beams.
14. The pallet of claim 11 wherein each of said plurality of base supports is substantially identical and thereby interchangeable.
15. The pallet of claim 11, wherein said plurality of base supports define an approximately flat bottom surface for resting on a flat surface.
16. The pallet of claim 11 comprising three cross beams and three base supports that intersect said cross beams at approximately 90°.
17. The pallet of claim 11, wherein said cross beams, said base supports are configured to define spacing to receive at least one of a forklift, pallet jack, hand truck, and automated lifting machinery.
18. The pallet of claim 11, wherein a plurality of said domes comprise a closed dome structure.
19. The pallet of claim 11, wherein at least some of said domes comprise an open dome structure defined by a plurality of arches having apexes that define said dome apex and two legs extending from each of said arch apexes that define said dome legs, thereby forming open areas between said dome legs.
20. The pallet of claim 11, wherein said plurality of domes are situated in a plurality of dome rows that extend in at least two directions and intersect each other at a non-zero angle to form a pattern.
Type: Application
Filed: Feb 22, 2005
Publication Date: Sep 8, 2005
Inventors: Conrad Herring (Del Mar, CA), Fredrick Reyhan (Diamond Bar, CA)
Application Number: 11/068,649