BACKGROUND OF THE INVENTION

1. Field of the Invention:

This invention relates generally to pallets and other structures designed to contain, support, and aid in the transport of cargo. This invention relates more specifically to such pallets and structures that are constructed primarily of corrugated cardboard.

2. Description of Related Art:

Structurally sound pallets are essential tools in the cargo shipping industry throughout the world. Whether cargo is being shipped by land, sea, or air, the handling of material necessitates the use of a practical means of supporting and moving unit amounts of goods.

The most common form of the shipping pallet is constructed of wood and is configured in one of two basic designs. A first wooden pallet design is constructed of 2"x4" wooden members, three to a pallet, which are laid parallel, on edge, and are cross connected by a series of l"x4" or l"x6" slats which form the top surface of the pallet.

A second wooden pallet design is constructed of nine or more discrete wooden blocks which function as spacers between two layers of parallel flat wooden slats. The advantage of this latter configuration is that it is approachable by a fork lift or other standard pallet moving device from any of its four sides. The 2"x4" design on the other hand is approachable only from two sides that are opposite each other across the pallet.

The disadvantages of both wooden pallet designs derive primarily from the fact that they are constructed of wood.

A first disadvantage is the fact that wooden pallets are typically very costly. Not only is the wood product itself expensive, but the configuration and construction of the pallet is complex and costly as well. Wood continues to become a scarcer and more valuable commodity, and recent concerns over the availability of harvestable trees have only increased wood's value and have spurred society's move towards substitute materials. A second disadvantage derives from the fact that wooden pallets have the potential for damaging a finished surface that the pallets might be used upon. In addition to the wooden members themselves being a problem, the nails used in the

construction of most wooden pallets are also likely to cause damage. It is nearly impossible for someone utilizing a wooden pallet on a sensitive surface to move cargo without causing some damage to that surface.

A third disadvantage to wooden pallets relates to their potential for damaging the cargo that is placed upon them. The same defects, splinters, and nails, that can damage floor surfaces can also be found on the support platforms of wooden pallets and can easily catch and cut into cargo being transported.

A fourth disadvantage of wooden pallets relates to their excessive weight. Whether the construction is of the 2"x4" design or the wooden block design, the heavy weight of the typical wooden pallet limits the ability of an individual to carry one, or at most two pallets when empty. Furthermore, while the cargo being transported on a pallet typically outweighs the pallet by a significant amount, the weight of a wooden pallet is substantial enough to be an important factor when determining the overall weight of a load being shipped. In spite of their disadvantages, wooden pallets do have the advantage of being reusable for a certain period of time or for a certain number of cycles of use. Inevitably, however, a wooden pallet will be damaged to the point that it can no longer safely transport cargo. At such a point, the damaged pallet becomes a disposal problem and can frequently end up occupying a large amount of space in disposal landfills.

It is estimated that over half of all shipping pallets are not returned to their point of origin after use. This means that the shipper must continuously buy new or used replacement pallets and to a great extent relies on the general circulation of used wooden pallets to provide a supply that is more cost effective than merely the purchasing of an unused new wooden pallet. Relying on this uncertain supply can be costly if a shipper's demand for pallets does not coincide with the arrival of a corresponding supply of used pallets. If a pallet user could rely on a constant supply of inexpensive pallets that did not fluctuate with the availability of recycled used pallets, it would certainly be to his advantage. Cardboard pallets have been conceived of and utilized for quite some time as an alternative to wooden pallets. Cardboard pallet designs that have been used in the past have solved many of the above described problems associated with wooden pallets.

Cardboard pallets are typically very cost efficient. The wood pulp that is the basic component of the cardboard material is less expensive than the structural wood components of a typical wooden pallet. Most all cardboard products are recyclable so the raw material for a cardboard pallet could come from recycled sources and the

cardboard pallet itself could be recycled.

Cardboard pallets may be used on surfaces that would otherwise be subjected to damage by wooden pallets. Cardboard pallets have a softer impact on both the surfaces they are placed upon and the cargo that is placed upon them. Cardboard pallets are significantly lighter in weight than wooden pallets of similar size and design. A number of empty cardboard pallets could be easily handled by a single individual and the weight that a cardboard pallet adds to the overall weight of a cargo load is almost insignificant.

Some cardboard pallet designs have the additional capacity to be reused. In the past, the number of use cycles for a cardboard pallet was limited, but optimizing a cardboard pallet's structural integrity can extend the number of use cycles in certain environments.

Also significant, is the fact that once a cardboard pallet is damaged beyond the point that it can be safely used, the pallet is not a disposal problem and can be recycled to create the raw material for additional cardboard pallets. Because of its recyclability and low cost, a cardboard pallet would more likely be turned in for recycling at an appropriate time. Because of their non-recyclability and high cost, wooden pallets are frequently used beyond the point that they can safely or sufficiently handle cargo. The problems associated with previous cardboard pallet designs have related primarily to their inability to hold up structurally as well as their wooden counterparts. There have likewise been problems associated with imitating the accessibility of the wooden pallet designs described above. It is, however, the lack of structural integrity that has to this point been the major barrier to a more widespread acceptance of the cardboard pallet.

Existing cardboard pallet designs are often limited to a very light load capacity. Their structural integrity generally deteriorates rapidly with use and usually restricts the pallet to a one time loading and unloading. For the most part, the structural soundness of a cardboard pallet has been directly* related to its cost. Cardboard pallets that are capable of handling greater loads not only require a more complex construction and higher material costs, but also require significantly higher manufacturing costs. Cardboard pallets that approach a wooden pallet's structural integrity frequently have not only this disadvantage of additional cost, but have significant additional weight as well. Certainly, a solid slab of corrugated cardboard, the size and shape of a typical wooden pallet, could handle any load that a wooden pallet could handle. Unfortunately, such solid slabs of corrugated cardboard are impractical both from a cost perspective and from a handling and

weight perspective. The required balance to be struck between structural integrity and cost and weight has heretofore not been met. No corrugated cardboard pallets have been able to optimize all of these factors.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a pallet made primarily of cardboard of sufficient structural integrity to be a substitute, in appropriate circumstances, for the standard wooden pallet.

It is another object of the present invention to provide a pallet made primarily of corrugated cardboard that is characterized by its structural integrity and that allows for access by lifting devices from any side.

It is another object of the present invention to provide a pallet made primarily of corrugated cardboard capable of supporting the loads more typically found used in conjunction with wooden pallets. It is another object of the present invention to provide a pallet made primarily of corrugated cardboard that is capable of maintaining its structural integrity in an environment that may expose the surface of the pallet to moisture. It is another object of the present invention to provide a pallet made primarily of corrugated cardboard that is low in cost both in terms of materials expense and manufacturing expense.

It is another object of the present invention to provide a pallet that is made primarily of corrugated cardboard that is recyclable by means of shredding the bulk of the pallet and reconstructing new cardboard elements from the shredded materia 1.

In satisfaction of these and related objectives, applicant's invention provides a pallet which is constructed primarily of layered and bonded sections of corrugated cardboard strategically placed on end and in orientations that provide a structural support imitative of wooden support members. Applicant's invention creates a pallet that in all respects performs to the standards of wooden pallets and overcomes the disadvantages of wooden pallets by way of its light weight, low cost and recyclability. Applicant's pallet design is constructed so as to allow access from more than a single direction and may incorporate appropriate sealants that will allow the cardboard pallet to come in contact with moisture without loosing its structural integrity.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a partially exploded, perspective view of a preferred embodiment of applicant's corrugated cardboard pallet.

Fig. 2 is a side elevational view of the embodiment shown in Fig. 1.

Fig. 3 is a detailed fragmentary view of one corner of the embodiment shown in Fig. 1.

Fig. 4 is a bottom plan view of an alternative preferred embodiment of applicant's invention. Fig. 5 is a side elevational view of the alternative embodiment shown in Fig.

4.

Fig. 6 is a detailed view of a typical section of corrugated layers in a preferred embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring first to Fig. 1, a partially exploded perspective view of a preferred embodiment, the fully assembled pallet is generally indicated by reference numeral (10). The fully assembled pallet is composed of three sections shown separated in this exploded view. The pallet frame is generally referred to by reference numeral (12). Top platform (14) and bottom platform (16), are shown removed from their positions on the fully assembled pallet (10).

Pallet frame (12) comprises a number of elements of layered and bonded corrugated cardboard material. These elements are themselves bonded together to form the structural frame (12). Three base slats (20) are aligned parallel one to another and are spaced equally apart to act as base support members. To the top of each base slat (20) are bonded and mounted three spacer blocks (18). Spacer blocks (18) are themselves positioned one at each end of each base slat (20) with a third placed equidistant from each end of each base slat (20). The combination of base slats (20) and spacer blocks (18) provides a rectangular array of nine spacer blocks (18) organized generally in the form of a square with three rows by three columns. Atop these nine spacer blocks (18) are positioned three intermediate slats (24). Intermediate slats (24) lay across spacer blocks (18), each intermediate slat (24) connecting a total of three spacer blocks (18). Intermediate slats (24) serve to connect the array of spacer blocks (18) into a single unit by way of their placement perpendicular to base slats

(20).

Finally, a plurality of top slats (22) are placed across intermediate slats (24) to further bind the overall framework and to provide a greater surface area upon which top platform (14) may be placed. In the preferred embodiment, there are five top slats (22) which are spaced evenly apart and are bonded to intermediate slats

(24). Top slats (22) are placed in a direction perpendicular to intermediate slats (24).

Once the structural frame (12) of pallet (10) is completely formed, top platform (14), constructed of a single sheet of corrugated cardboard is bonded and attached to the upper surfaces of top slats (22). Bottom platform (16) which is also composed of a single sheet of corrugated cardboard is bonded and attached to base slats (20).

Referring now to Fig. 2, a side view of the embodiment shown in Fig. 1, the spacing and elevation of the pallet components can be seen. Top platform (14) and bottom platform (16) have been positioned as they would normally be attached on pallet (10) . Top slats (22) are seen edge on and are displaced equidistant apart with a top slat (22) along each edge of pallet (10) and with the spacing between each top slat (22) being approximately equal to the width of each top slat (22). Top slats (22) are shown supported by intermediate slats (24) with a single intermediate slat (24) shown across its side in the view in Fig. 2. Beneath intermediate slats (24) are three spacer blocks (18). Beneath spacer blocks (18) are base slats (20), with spacer blocks (18) mounted on each end thereof. Base slats (20) are seen edge on as they are generally parallel to top slats (22) in this embodiment.

Fig.3 is a detailed fragmentary view of one corner of the embodiment shown in Fig.1. In Fig.3, spacer block (18) is shown positioned atop and bonded to one end of base slat (20). Intermediate slat (24) is positioned atop and bonded to spacer block (18). Finally, top slat (22) is positioned atop and bonded to intermediate slat

(24).

In the detailed fragmentary view of Fig.3, the orientation of the corrugated layers can be better seen. Corrugated layers (20a-n) of base slat (20) form a series of parallel, planar segments whose dimensions are defined by the length and the thickness of base slat (20). Spacer block (18) is composed of corrugated layers (18a- n) which are planar segments that have dimensions equal to the height and width of spacer block (18). In this embodiment, the planar segments of spacer block (18) are aligned generally parallel to and coincident with the planer segments which define the corrugated layers (20a-n) of base slat (20). Corrugated layers (24a-n) which are bonded together to create intermediate slats (24) are, as with base slat (20), defined by planar segments whose dimensions are equal to the length and the thickness of intermediate slats (24). Finally, corrugated cardboard layers (22a-n) which are bonded together to form top slats (22) are generally defined by planar segments which, as with bottom slats (20) and intermediate slats (24), have dimensions approximated by the length and the thickness of top slat (22). The planar segments

(24a-n) of intermediate slats (24) are positioned atop spacer blocks (18) with one dimension aligned with the planar segments (18a-n) of spacer blocks (18), but with

a second dimension at right angles with planar segments (18a-n) of spacer blocks (18). Likewise, the orientation of the planer segments (22a-n) comprising top slats (22) are oriented at right angles to intermediate slats (24) and are generally co- planar with planar segments (18a-π) of spacer blocks (18) and the planar segments (20a-n) of base slats (20). The arrangement of layers of corrugated cardboard shown in Fig. 3 provides the strongest structural support possible given the elements which comprise pallet (10). The three upper elements in the layers shown, namely top slats (22), intermediate slat (24), and spacer blocks (18) are all positioned by alternating the direction of the corrugated layers. Ideally, the bottom layer formed by base slats (20) would likewise be oriented at right angles to spacer blocks (18). However, the overall requirements of the structure demand that base slats (20) are aligned at right angles to intermediate slats (24) and are necessarily, therefore, positioned parallel to the planer segments (18a-n) in spacer blocks (18).

Fig. 4 is a bottom plan view of an alternative preferred embodiment of applicant's invention. Pallet (30) shown in Fig. 4, is a larger pallet with a greater overall surface area upon which cargo might be placed. The view in Fig. 4 discloses the arrangement of elements which structurally create pallet (30). Four base slats (40) arc arranged parallel one to another and are spaced apart so as to form an arrangement upon which the balance of pallet (30) can be built. Not seen in Fig. 4, are spacer blocks (38) (shown in Fig. 5) which form an array of supports that are mounted to the top surfaces of base slats (40). The positions of spacer blocks (38) are generally seen as the intersections of base slats (40) and intermediate slats (44). Atop each spacer block (38) is mounted an intermediate slat (44). Intermediate slats (44) each connect a row of four spacer blocks (38) and thereby create a unitary structure which connects base slats (40) together. Intermediate slats (44) are directed perpendicular to base slats (40) and, in the preferred embodiment, are three in number so as to cover the entire array of twelve spacer blocks (38).

Finally, a plurality of top slats (42) are placed perpendicularly across intermediate slats (44) to provide a top surface on which is placed and bonded top platform (34). As in the previous embodiment, top slats (42) are positioned and spaced so that there is one along each of two edges of the top surface of pallet (30) with the balance spaced between these edge top slats (42) at distances from each other approximately equal to the width of each top slat (42). Portions of the underside of top platform (34), which is a single sheet of corrugated cardboard, can be seen between the structural members that form the framework of pallet (30).

Referring now to Fig. 5, a side elevational view of the alternative embodiment shown in Fig. 4, the placement of spacer blocks (38) can be more readily

seen. Again, base slats (40) provide the foundation upon which the balance of the structure of pallet (30) is built. Base slats (40) are seen on their edge in Fig. 5 and are shown with spacer blocks (38) attached and bonded to the top thereof. Fig. 5 discloses a single row of spacer blocks (38), this row being made up of four spacer blocks (38), there being three such rows to form an array of twelve spacer blocks

(38). Intermediate slat (44) shown is one of four intermediate slats (44) which cross and connect the combination of spacer blocks (38) and base slats (40). Finally, atop intermediate slats (44), are seen top slats (42) in an edge on view with top platform (34) displaced across the entire surface formed by top slats (42). Fig. 6 is a detailed view of one embodiment of the corrugated layered construction. The embodiment in Fig. 6 discloses a section generally described as (48) that is representative of any of the layered and bonded corrugated cardboard elements. These layered and bonded corrugated elements may be constructed by alternating a layer of flat cardboard (50) with a layer of corrugated cardboard (52). In a preferred embodiment, this sequence is followed by a subsequent flat layer of cardboard (54). Another preferred embodiment not shown, could contain layers of corrugated cardboard that each comprise a flat, a corrugated, and a second flat cardboard layer. This would create a bonded section whose layers would follow: flat, corrugated, flat, flat, corrugated, etc. The particular layering configuration is not as important as is the overall orientation of these layers with respect to one another in the complete pallet.

The embodiment disclosed in Fig. 4 and 5 is constructed with bonding layers directed in the same planes as those seen in the embodiment of Fig. 1, 2, and 3. In fact, the detail shown in Fig. 3 is applicable to the embodiments of Fig. 4 and 5 as much as it is to that of Fig, 1 and 2. This above described cross hatching of corrugated layers provides the greatest strength possible given the structural configuration required by the pallet design.

A number of modifications are possible to either or both of the above described embodiments. The surface platforms (14) and (16) may be omitted from the manufacture of pallet (10) so that pallet (10) is comprised solely of the structural framework (12). The advantage of this configuration is a reduction in overall mass and there ore weight, but along with this advantage, is the disadvantage of having less shear stability. While platforms (14) and (16) add little to the vertical support or vertical structural stability of the pallet, the platform surfaces (14) and (16) do serve, when bonded to the appropriate structural elements, to prevent the structural deformity of the pallet when the pallet experiences shear stresses. The platform surface (14) is additionally advantageous when small and/or potentially loose

articles of cargo are to be placed upon the surface of the pallet.

As the embodiment disclosed in Figs. 4 and 5 indicates, it would also be appropriate to omit the base platform shown as (16) in the embodiment of Figs. 1 and 2, so as to reduce weight while maintaining the upper platform (14) as both a structural and a cargo supporting member.

Every pallet element disclosed in the above description may, prior to its assembly, be coated and sealed with an appropriate water repellant sealant. Such a sealant would add minimally to the overall weight of the pallet and would allow pallet to be utilized in a moist environment. If it is not anticipated that the pallet will encounter a moist environment, the sealant may be dispensed with so as to decrease the overall cost and weight of the pallet.

The configurations shown in each of the embodiments are designed to allow for the easy access by standardized pallet moving machinery to any side of the pallet. From the direction shown in Figures 2 and 5, a pallet moving device which has wheels on the front ends of the prongs of a pallet fork may be inserted under the pallet with little or no obstruction. Other pallet moving machinery, such as a typical fork lift, may access each of the embodiments from either direction. Machinery of this type typically have a fork structure that allow access to a pallet either adjacent to the floor surface or slightly above the floor surface, as with the front side of the pallet arrangement shown in Fig. 1.

DETALIED DESCRIPTION OF AN ALTERNATIVE EMBODIMENT

While the preferred embodiment of the present invention is described above as being constructed entirely of corrugated cardboard material, alternative embodiments of the present invention are possible that utilize some minimal amounts of wood for certain components in specific applications. These alternative embodiments acheive most, if not all, of the same advantages described above with reference to pallets made entirely from cardboard. One alternative embodiment incorporates wooden boards in place of corrugated cardboard material for base slats (20) shown in Fig. 1. The use of wood for base slats (20) does add some weight to the pallet but it eliminates the necessity, in some situations, of waterproofing the corrugated cardboard, and therefore eliminates the weight associated with the waterproofing substance. If it is anticipated that the loaded pallet might be placed onto a floor surface that is wet, the use of wooden base slats (20) prevents the deterioration of the pallet prematurely.

This same embodiment is also preferable where pallet moving machinery will likely expose the base of the pallet to a significant amount of localized or abrasive impact. Corrugated cardboard material can withstand significant pressures if these pressures are distributed over a broad area. In some situations however, base slats (20) may be subjected to repeated, localized impacts that could eventually undermine the pallet's structurally integrity. Some pallet conveyor systems for example expose a pallet to repeated contact with small metals rollers, metal bearings, or even metal chain linkages. Such conveyors can eventually tear into the corrugated base layer of a pallet and destroy its ability to hold cargo. The replacement of base slats (20) with wooden members eliminates the above described problem and at the same time only slightly increases the weight of the pallet.

In this alternative embodiment base slats (20) would still be bonded to spacer blocks (18) using a suitable adhesive. Thus, even though there exists the possibility of marring a sensitive surface with the wooden material, there are no nails to compound the probem.

A second alternative embodiment utilizes a thin sheet of plywood in place of corrugated cardboard for top platform (14). The reasons for making this substitution are basically the same as those for replacing base slats (20); repeated localized impacts. If the cargo to be shipped has characteristics that subject the top layer of the pallet to uneven pressures, it may be preferable to substitute a thin, rigid plywood sheet for the corrugated layer in order to maintain the structural integrity of the pallet. As with the substitution of base slats (20), the weight of the pallet is only slightly increased in order to gain significant advantages in certain situations where carbo characteristics are adverse to a corrugated top surface. The above descriptions are not intended to limit applicant's invention but are intended as descriptions of preferred embodiments. Additional embodiments will be made clear from the attached drawing and from the following claim language.