Metal Pallet

Abstract

A lightweight, high-strength metal pallet is provided that includes a deck and a plurality of runners. Each one of the runners includes either a box-like skin and cellular support members disposed therein or a vertical web disposed within the cellular support members. The deck may also be formed of plywood or similar material. The cellular support members are oriented substantially vertically within the runner skin, and preferably form hex-cells, such that the pallet may withstand some crushing or other damage without catastrophic failure. Preferably, the deck, the skins or the webs and the support members are formed of ungalvanized steel to enable the steel pallet to be disposed in a steel remelt furnace after a single service, such as shipping refractory bricks to a steel manufacturing facility. The pallet may be formed of coated or galvanized steel for re-use. Pallets formed of other metals are also disclosed.

Description

FIELD OF THE INVENTION

[0001] The present invention relates to pallets, and more particularly, to a metal pallet having a honeycomb cellular runner design, and even more particularly, a pallet that includes a honeycomb cellular runner design and that is capable of being recycled after only one use.

BACKGROUND

[0002] Pallets constructed of wood are employed for carrying or shipping a wide variety of products in part because of their relatively low initial cost. Wooden pallets, however, have numerous drawbacks, including being unhygienic, easily damaged, and relatively heavy, and also possibly having a short useful life. Further, wooden pallets have generally been increasing in cost over the past few decades in part because of the rising cost of lumber. Although pallets formed of metal (such as steel, stainless steel, or aluminum) or plastic have been designed to alleviate these drawbacks, wooden pallets remain popular. An advantage of metal pallets, and particularly steel pallets, is that they may be recycled, providing that the metal and any coatings are suitable for such recycling, by disposing the metal pallets into a remelt furnace such that the pallets are melted with other scrap of similar composition.

[0003] Several designs of pallets, particularly steel pallets, have been developed in efforts to provide pallets that are cost effective and overcome the drawbacks of wooden pallets. For example, U.S. Pat. No. 4,485,744 (“Umemura”) teaches a pallet fabricated of plural longitudinal frames or runners, each of which is formed by a pair metal plate members that are coupled together by vertical support members spaced intermittently along the frame. The components are formed of galvanized iron sheets.

[0004] U.S. Pat. No. 3,602,157 (“Cohen”) teaches a pallet fabricated of plural longitudinal channels or runners each having a C-shaped transverse cross section. Plural vertically oriented plates are disposed at spaced intervals therein for enhancing the rigidity of the channels.

[0005] U.S. Pat. No. 4,424,752 (“Aberg”) discloses a pallet having a corrugated deck below which are support beams or legs spaced intermittently and formed by folding the deck sheet metal to form a U-shape.

[0006] U.S. Pat. No. 4,220,100 (“Palomo”) discloses a pair of solid exterior decks having a pair of corrugated truss members and a core disposed therebetween. In this regard, Palomo is without runners altogether and the truss members distribute the loads over the entire pallet surface along the corrugations.

[0007] U.S. Pat. No. 3,172,374 (“Allen”) discloses a pallet having a continuous deck beneath which are three runners. Each of the runners includes a top runner having side and central corrugations and a bottom runner nested within the top runner and having corrugations to form a W-shape in transverse cross section. United

[0008] U.S. Pat. No. 2,919,875 (“Mendel”) discloses a pallet that is formed of an alloy similar to the ingots or bars that are intended to be stacked onto the Mendel pallet. Therefore, the Mendel pallet may be used for the same purpose as its cargo, which presumably is a raw material that may undergo further processing. Because the Mendel pallet is the same material as its cargo, the weight of the Mendel pallet is likely not important because the pallet weight does not diminish the effective payload (that is, the net weight of the cargo).

[0009] An exemplary use of pallets is the shipment of refractory material, including refractory brick or dry mix, to steel manufacturing plants. A typical cargo load of such a shipment may be between 1500 kg to 2500 kg (3,300 lb. to 5,500 lb.). Pallets carrying such a typical load often are stacked from three to seven pallets high. Storage at an end-user's facility may be on uneven surfaces and exposed to weather for period of up to one year. The pallets often are handled by forklift and by overhead cranes.

[0010] Because they are subject to harsh environments, rough handling, and high loading requirements, pallets for shipping refractory material and pallets for shipping many other cargoes are typically designed for high strength and durability, and non-standard or custom pallets are often specified for such shipments. Further, pallets are often provided with a galvanized or other coating to resist corrosion. Because steel mills are spread through the world, transportation back and forth of such non-standard or custom pallets is expensive and time-consuming.

[0011] Conventional pallets may be used to carry raw or finished food during processing. Food processing pallets have unique requirements, including being light weight, being easily sterilizable, such as by high temperature autoclaving, having no closed areas, and having impermeable, smooth surfaces. In this regard, stainless steel, aluminum, and plastic are often used for food service. Plastic is light weight, but unfortunately has several drawbacks for food processing, including having temperature limits for cleaning and having surfaces that may be easily damaged or roughened, and that often require polishing to meet government and related specifications. Stainless steel or aluminum materials overcome some of these drawbacks, but conventional stainless steel and aluminum pallet designs are relatively heavy, which increases pallet cost and handling cost and complexity.

[0012] Despite the numerous existing pallet configurations, metal pallets are reported to be difficult to produce and to have relatively high weight and cost, especially when designed for the high loadings described above. Further, the galvanization and some other coatings often employed inhibit recycling by making the pallet not suitable for disposal in a remelt furnace. There is a need for new approaches to pallet design and new methods of handling pallets.

SUMMARY

[0013] A lightweight, high-strength metal pallet is provided that includes a deck and a plurality of runners, each of which is formed of a material comprising a metal. The deck has a top surface and a bottom surface. Each of the runners is coupled to the bottom surface of the deck. Each one of the runners includes a skin and cellular support members. The skin is formed of a material comprising a metal and has a shape that is substantially box-like. Preferably, the deck, the skins, and the support members are formed of ungalvanized steel, thereby enabling the pallet to be disposed in a steel remelt furnace after a single service. The cellular support members are formed of a material comprising a metal and are coupled to each one of the skin and the deck. The cellular support members are disposed substantially vertically within the runner, and preferably form hex-cells. Thus, the top surface of the pallet is suitable for receiving a cargo thereon and the runner cellular structure enhances the rigidity and strength of the pallet. Apertures may be provided in the skin to enable access to the interior thereof.

[0014] Such a pallet has an initial failure mode (or yield mode) in which the deck, which preferably has corrugations, yields before the runners yield. Such an initial failure mode of the deck, however, depends upon the particular, desired characteristics of the pallet. The cellular runner design encompasses a honeycomb design, especially a vertically oriented hex-cell support structure, within a skin such that it may withstand crushing without catastrophic failure.

[0015] The runner configuration may be employed with virtually any decking, such as a plywood sheet, to obtain the benefits relating to the runners. Thus, the runners (having a skin and cellular reinforcement) may be employed for a pallet that is intended for re-use (that is, the pallet is suitable for carrying a cargo load through several cycles of loading, transporting, and unloading). Such a re-usable pallet having the runners disclosed herein may be galvanized or have other coatings.

[0016] According to another aspect of the present invention, a method of processing a pallet capable of carrying various useful cargo includes the steps of: receiving cargo on the pallet that is formed of ungalvanized steel and is lightweight; unloading the cargo from the pallet; and disposing the pallet in a steel remelt furnace for melting of the pallet. The cargo carried by the pallet preferably is not ungalvanized steel, but may be refractory brick or other product destined for a steel manufacturing facility. Thus, the melted pallet is suitable for making recycled steel.

[0017] In this regard, such a pallet may include a top surface and a bottom surface, and a plurality of runners formed of a material comprising a metal and coupled to the bottom surface of the deck. Each one of the plurality of runners includes a skin and cellular support members. The skin is formed of a material comprising a metal and has a shape that is substantially box-like. The cellular support members are also formed of a material comprising a metal, and are coupled to each one of the skin and the deck and disposed substantially vertically and substantially within the runner. Such a pallet, or another pallet having the runners described above, is especially suitable for use single service use applications because it is able to withstand damage without catastrophic failure. Thus, the cargo load may be delivered even though the pallet may not be suitable for future shipments.

[0018] Because the pallet may be formed of an ungalvanized steel, the pallet may be disposed directly into the steel remelt furnace upon delivery of its cargo load of refractory bricks to a steel manufacturing facility.

BRIEF DESCRIPTION OF THE FIGURES

[0019] FIG. 1 is a top view of the steel pallet according to an aspect of the present invention;

[0020] FIG. 2A is an enlarged perspective, sectional view of a portion of the steel pallet shown in FIG. 1;

[0021] FIG. 2B is an enlarged perspective, sectional view of another portion of the steel pallet shown in FIG. 1;

[0022] FIG. 2C is an enlarged, partially exploded, perspective, sectional view of yet another portion of the steel pallet shown in FIG. 1;

[0023] FIG. 3 is an end view of the steel pallet taken according to lines 3-3 in FIG. 1;

[0024] FIG. 4 is a sectional view taken through a portion of the steel pallet along lines 4-4 in FIG. 3;

[0025] FIG. 5 is a side view of the steel pallet taken according to lines 5-5 in FIG. 1;

[0026] FIG. 6 is a top view of a component of the steel pallet shown in FIG. 1;

[0027] FIG. 7 is an end view of the component of the steel pallet taken according to lines 7-7 in FIG. 6;

[0028] FIG. 8 is an enlarged view of an a portion of the component in FIG. 7;

[0029] FIG. 9 is an enlarged view of a sub-assembly of the steel pallet shown in FIG. 1;

[0030] FIG. 10 is an end view of the sub-assembly taken according to lines 10-10 in FIG. 9;

[0031] FIG. 11 is an enlarged view of another sub-assembly of the steel pallet shown in FIG. 1;

[0032] FIG. 12 is an end view of the sub-assembly taken according to lines 12-12 in FIG. 11;

[0033] FIG. 13 is a top view of a portion of the steel pallet shown in FIGS. 1 and 2A, 2B, and 2C;

[0034] FIG. 14 is a side view of a pallet according to another embodiment of the present invention; and

[0035] FIG. 15 is an enlarged, perspective view of a pallet according to yet another embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0036] Referring to the figures to illustrate a preferred embodiment of a first aspect of the present invention, and particularly FIGS. 1 through 5, a steel pallet that has high strength and light weight, and is easy and inexpensive to manufacture, including using a small number of shapes, is provided. In this regard, a steel pallet 10 includes a deck 12 and plural runners, such as a pair of outer runners 14a and 14c and an inner runner 14b. Each component of pallet 10 is formed of sheet carbon steel having a standard “mill finish”, and preferably is not painted or galvanized. Exemplary dimensional and manufacturing information is provided herein to illustrate an embodiment of the pallet 10. The present invention, however, is not limited to such exemplary information. Rather the present invention encompasses embodiments that will be apparent to persons familiar with pallet design and/or steel fabricating techniques in light of the present disclosure.

[0037] Referring particularly to FIGS. 6 through 8, deck 12 preferably is formed by a corrugated steel sheet. The corrugations preferably include an outboard corrugation 20a on each side of deck 12 with plural inboard corrugations 20b therebetween. The dimensions of the corrugations and thickness of the steel deck may be chosen according to the desired properties of the deck, including the strength and rigidity as required by the load and duty. The exemplary corrugated sheet is formed of 24 gauge steel and the inboard corrugations 20b are approximately 1.79 inches (4.55 cm) wide, as indicated by dimension D1 in FIG. 8. The outboard corrugations 20a are approximately 1.64 inches (4.17 cm) wide, as indicated by dimension D2 in FIG. 8.

[0038] Each of the corrugations 20a and 20b preferably form a flat top surface 22 and an opposing flat bottom surface 24. As such, the upper portions of corrugations 20b provide multiple flat surfaces 22 such that the gap between adjacent flat surfaces 22 is less than about 1.0 inches (2.54 cm). The lower portions of corrugations 20b preferably provide multiple flat surfaces 24 such that each flat, bottom surface 24 is approximately 0.25 inches (0.0.64 cm) wide. The total height of deck 12 (that is, between the upper and bottom portions, respectively, of surfaces 22 and 24) is approximately 1.0 inches (2.54 cm). The trough angle, indicated as A1 in FIG. 8, is preferably 15 degrees, which yields a gap between adjacent flat surfaces 22 of much less than 1.0 inches (2.54 cm). Depending on the desired strength and rigidity of the pallet, the width of the bottom surface 24 may be determined by the minimum width that provides a sufficient surface for the desired spot weld, and/or other welding (or fastening) and manufacturing considerations relating to the particular sheet metal machinery used to provide the breaks as will be understood by persons familiar with such design and manufacturing processes. The weld connections of deck 12 to runners 14a, 14b, and 14c are described below.

[0039] As shown in generally in FIGS. 9 through 12, runners 14a, 14b, and 14c each include a skin 16 and a support member, such as honeycomb support 18, disposed within or enclosed within skin 16. Skin 16 includes first and second skin sidewalls 26 and 28 and a skin bottom wall or member 30 disposed therebetween. Preferably, walls 26, 28, and 30 each are a long rectangle and formed by breaking an integral, rectangular, 26 gauge steel sheet to form a rectangular box-like structure having an open top and ends. Multiple elongated apertures 31 are formed in bottom member 30.

[0040] Each skin also forms a pair of longitudinal flanges to provide a welding surface for attaching runners 14a, 14b, and 14c to the bottom surface 24 of the corrugations of deck 12. Referring particularly to FIGS. 1, 2B, 2C, 9, and 10 to illustrate inner runner 14b, a welding flange 32 is formed on each of the first and second skin sidewalls 26 and 28 of inner runner 14b. Welding flanges 32 preferably are formed by breaking a portion of the steel sheet above each skin sidewall. Flanges 32 preferably extend laterally outwardly approximately 0.5 inches (1.27 cm) from each sidewall of runner 14b and from the inner sidewall of each runner 14a and 14c (that is, toward the inner runner 14b) along the length of the runners.

[0041] Referring particularly to FIGS. 1, 2A, 11, and 12 to illustrate outer runners 14a and 14c, a welding flange 32 is formed on the skin sidewall on the inboard side (that is, the side facing inner runner 14b) of each outer runner. Welding flange 32 on runners 14a and 14c are the same as describe above with respect to inner runner 14b. Another welding flange or wing 34 is formed on the outboard skin sidewall of each outer runner 14a and 14c and extends outwardly therefrom along the length of the runners.

[0042] Wing 34 is best shown in FIG. 2A. Each wing 34 includes a substantially planar extending portion 36a and an inwardly facing C-shaped portion 36b at the distal end of extending portion 36a such that the C-shaped portion is spaced apart from the outboard skin sidewall. Wing 34 is best shown in FIGS. 2A and 2C although most of the other portions of the outboard runner are omitted from FIG. 2C for clarity.

[0043] The distance between the outboard sidewall (that is, the box-like portion of the skin 16) of each of the runners 14a and 14c and the outboard portion of its wing 34 is approximately 3 inches (7.62 cm). Each wing 34 preferably is formed from the same contiguous steel sheet that forms skin 16 by breaking such sheet to form extending portion 36a and C-shaped portion 36b. Such wings cap the side of deck 12 and provide support for the portion of deck 12 that overhangs (that is, is disposed outwardly over the outer portion of) runners 14a and 14c.

[0044] A plurality of access holes 38 are formed in extending portion 36a along the length thereof. Access holes 38 are provided such that they align with the upper portions of each corrugation so as to provide access to the underside of deck top surface 22 of each corrugation upon assembly of the deck 12 and runners 14a and 14c, as described more fully below. Access holes are shown in phantom in FIGS. 1 and 11, shown in FIG. 2A, and omitted from FIG. 2C for clarity.

[0045] End flanges 33 are formed at the longitudinal ends of each runner 14a, 14b, and 14c. Preferably, end flanges 33 are formed by breaking the same steel sheet as that forming the skin 16. Each flange 33 is folded over each end of each runner to form an end cap that partially encloses the internal runner box. The end caps preferably do not fully enclose the ends of the runners so as to enable access therein for inspection and fumigation purposes, while enhancing safety by protecting against rough edges and enhancing loading by stiffening the edge of the pallet. End flanges 33 are shown in FIGS. 9 through 12, and omitted from FIGS. 2A, 2B, and 2C for clarity. Persons familiar with the breaking operations will be able to choose the size and shape of the initial flat steel sheet from which runners 14a, 14b, and 14c are fabricated according to well-established manufacturing principles.

[0046] A cellular supporting structure preferably is disposed within each runner. Preferably, the cellular supporting structure is vertically oriented and forms a honeycomb shape, such as hexagonal supports 18, in transverse cross section, as best shown in FIGS. 1, 2A, 2B, 2C, 9, 10, 11, and 12. Each hexagonal support 18 preferably forms a hexagon in transverse cross section, and may be referred to as a “hex-cell”. Each hex-cell support 18 includes a bottom edge 48 and a top edge 50, as best shown in FIGS. 2A, 2B, and 2C. Each support 18 preferably is formed by an opposing pair of ribbon support members 40a and 40b. Ribbon support member 40a, a top view of which is shown in FIG. 13, is substantially identical to ribbon support member 40b, but opposite hand, as shown in FIGS. 9 and 11.

[0047] Each ribbon support member 40a and 40b includes an inner portion 42, an opposing outer portion 44, and a pair of oblique portions 46a and 46b disposed between portions 42 and 44. Each portion 42, 44, 46a, and 46b is preferably a substantially planar sidewall of the hex-cell. At one end of each of ribbons 40a and 40b, an extension 52 extends obliquely from the distal end of the oblique portion. Likewise, another extension 52 extends from the right-most oblique portion 46b of ribbon support member. Preferably, each ribbon 40a and 40b is formed of a 26 gauge steel sheet that is broken to form a series of half hexagons, in transverse cross section, that form the hex-cell shape upon joining together as described above.

[0048] As best shown in FIGS. 2A, 2B, 2C, 9, 10, 11, and 12, ribbons 40a and 40b are disposed within skin 16 such that the inner portions 42 of ribbons 40a and 40b are abutting. The outer portions 44 contact the inner portion of the skin sidewalls 26 and 28. As shown in FIGS. 9, 11, and 13, extension 52 extends from the left-most oblique portion 46b such that extension 52 of ribbon support member 40a is parallel and in close contact to the left-most oblique portion 46b of ribbon support member 40b.

[0049] The height of ribbons 40a and 40b is chosen to match that of the inner depth of skin 16 such that the honeycomb support bottom edge 48 contacts skin bottom member 30 substantially along the length of the runner, taking into consideration manufacturing tolerances. Honeycomb support 50 is substantially flush or even with the upper surface of flanges 32 and extending portion 36a.

[0050] As shown in FIGS. 2A and 2B, ribbons 40a and 40b preferably are joined together by welds, such as three 0.125 inch (0.32 cm) spot welds 56 at each of the inner portion 42 interfaces. Each ribbon 40a and 40b preferably is joined to its respective skin sidewall 26, 28 by three 0.125 inch (0.32 cm) spot welds 56. Upon welding of the honeycomb supports 18 into the skins 16 formed as described above, the runner sub-assemblies 14a, 14b, and 14c are complete. Apertures 31 provide viewing or access to the internal portion of each hex-cell structure from the bottom of the pallet 10 by, preferably, being aligned with ribbon inner portions 42. Apertures 31 may be important for enabling inspection of the welds 56 at ribbon inner portions 42 after assembly, viewing of the internal portions of the runners for customs or border inspections, access to the internal portions of the runners for fumigation, and the like.

[0051] Inner runner 14b may be aligned with the longitudinal centerline of deck 14, and each flange 32 is joined to the deck bottom surface 24 by a 0.125 inch (0.32 cm) spot weld 56 at each corrugation along corrugation trough centerlines 54 as shown schematically in FIGS. 2A and 2B. Each outer runner may be assembled to deck 12 by inserting each of the side edges of deck 12 into the C channel of portion 36b. The inboard flange 32 is welded as described above with respect to flange 32 of inner runner 14b. The uppermost surface of the C-shaped channel is welded to deck top surface 22 by 0.125 inch (0.32 cm) spot welds 56 at each corrugation. Holes 38 provide access to the underside of top surface 22 of each corrugation to facilitate such welding.

[0052] The cellular reinforcement within a box-like skin, as described herein, provides a lightweight, strong pallet design. Such a skin stiffens a pallet in the longitudinal direction, at least in part, by having a high moment of inertia. The corrugations, as described by corrugations 20a and 20b, because they are nominally perpendicular to the longitudinal axes of the runners, stiffen the pallet 10 in a transverse direction. The cellular reinforcement augments the longitudinal stiffness of the skin, and enhances crushing strength of the runner. The runners also stiffen the deck in the transverse direction, at least over the portion of the deck to which the runners are attached.

[0053] The cellular reinforcement, as provided for example in runners 14a, 14b, and 14c, distributes the load along the length of the pallet, and provides numerous contact points between the support members and the deck corrugations, thereby enabling the deck to be formed of a thinner material than would be required with fewer contact points. For example, honeycomb support top edge 50 contacts deck bottom surface 24 at each corrugation. Preferably, top edge 50 is not fastened to deck bottom surface 24, but rather is merely in contact therewith. However, the present invention encompasses welding or otherwise fastening the honeycomb supports directly to the deck, and such a configuration may employ tabs, flanges, or other structures to enhance the welding process. Each point of contact therebetween provides a bearing point in which the pallet cargo load may be transmitted to the corresponding runner. Moreover, the numerous contact points allow localized runner damage such that several cells or honeycombs may be damaged without structural collapse of the entire pallet.

[0054] For the exemplary pallet having the configuration, dimensions, materials, and sheet thicknesses described above, as well as a pallet according to the dimensions provided above that is fabricated of 24 gauge sheet steel for each of the deck 12, skin 16, and ribbon support members 40a and 40b, the initial static yielding mode is crushing of the deck corrugations upon being loaded with a static semi-rigid load, such as that provided by refractory bricks.

[0055] In this regard, for any pallet having the cellular runner structure or geometry described herein, at least in part because the cellular runner structure has numerous bearing points that are dispersed along the length of the pallet, as the initial collapse begins, the bearing surface actually increases as the cell structure buckles, which significantly delays further failure to provide a gradual rather than sudden failure. Any pallet having the cellular runner structure described herein, such as pallet 10, promotes safety by, for example, providing surfaces without rough edges and possibility of splinters, providing gradual yielding by compression rather than sudden brittle failure (that is, catastrophic failure), and providing the capability of receiving severe local damage without total failure.

[0056] In this regard, the pallet 10 (or 10′ and 10″, as described below) is capable of sustaining damage, such as local crushing, that may render the pallet unsuitable or unattractive for re-use, but that does not result in catastrophic failure of the pallet such that the cargo load may be delivered to its desired site. For example, pallet 10 may have local crushing of the deck, local or minor crushing of the runners 16, or other damage that is sustained during loading, transporting, or unloading of its initial cargo load. In this regard, several individual cells or honeycombs may be damaged without affecting adjacent cells, thus allowing the pallet to retain structural integrity.

[0057] Even though the pallet may have sufficient integrity to safely deliver its initial cargo load to its desired destination, the damage may make loading of another cargo difficult or unsafe. Thus, a single use may be beneficial, and would save the added costs of administering inventory of and re-shipping the pallet, and related costs.

[0058] The actual total cost of the pallet depends in part on the number and size of the welds, the thickness of the steel employed to make the runners and deck (where applicable); and the number and complexity of the pieces of each shape used to form the pallet. Each pallet 10 consists of ten pieces of formed sheet steel in four shapes: 1) one deck 12; 2) six ribbon support members 40; 3) two outer runner skins, 14a and 14c, which include welding flange 32, wing 34, and end caps formed by end flanges 33; and 4) one center runner skin 14b, which includes a pair of welding flanges 32 and end caps formed by end flanges 33. The manufacturability, including labor cost and time, and material costs, of the pallet 10 is enhanced by the relatively small number of shapes, each of which may be formed by standard sheet metal fabricating equipment, and relatively uniform spot welds.

[0059] The exemplary pallet has overall dimension of 49.1 inches long (124.7 cm) and 37.2 inches (94.5 cm) wide from the outermost portions of the C-shape portions 36b. The box portion of each of the runners 14a, 14b, and 14c is approximately 4.0 inches (1.01 cm) wide and 3.0 inches (7.62 cm) deep, and is approximately 36 inches (91 cm) long so as substantially to span the entire transverse dimension of pallet 10, except for about a one-half inch overhang on each side thereof.

[0060] Such an exemplary pallet 10 has been demonstrated to handle loadings up to 3,680 lb/ft2 (18,000 kg/m2) before compression crushing (that is, plastic yielding) of the pallet begins. In practice, pallet 10 safely completed its service with the loading of 3,680 lb./ft2 (18,000 kg/m2). Such a loading may include a single heavy cargo load or numerous light cargo loads on pallets stacked one on top another. Further, the exemplary pallet has been demonstrated to withstand overloading when stacked without catastrophic failure of the pallet. The exemplary pallet 10 has also been demonstrated to handle continuous, experimental service with a cargo in excess of 28,000 lb. (11,365 kg). Despite such high loading capability, the exemplary pallet weighs less than 55 lb. (25 kg), and thus can be handled by a single person, and falls within applicable regulatory limits. In fact, the pallet 10 formed of the 24 and 26 gauge steel sheets as described herein weighs approximately 35 lb. (16 kg).

[0061] As such, pallet 10 is light weight while exhibiting high strength. Pallet 10 (formed as described herein of 24 and 26 gauge steel sheets) has been loaded to 46,000 lb. (20,909 kg) total static load before yielding occurs. Thus, pallet 10 provides a payload to pallet weight ratio, as a measure of lightweight and high strength attributes, of over 1,300:1 and well over 1,000:1.

[0062] Referring to FIG. 14 to illustrate another embodiment of the pallet according to the present invention, a pallet 10′ includes a deck 12′ and plural runners 14a, 14b, and 14c. Deck 12′ may be formed of any sheet material, and preferably is a plywood sheet, such as standard ¾ inch plywood, wooden boards, and the like. Deck 12′ provides a substantially flat and continuous top surface 22′ and bottom surface 24′. Runners 14a, 14b, and 14c may be as described above with respect to the first embodiment of the pallet, except that flanges 32 and 34 are provided with numerous small holes for attaching deck 12 thereto by fasteners, such as bolts 13, as shown schematically in FIG. 14. Bolts 13 may be countersunk into the top surface 12′ to provide an even top surface 22′.

[0063] As evident from the embodiment illustrated by pallet 10′, runners 14a, 14b, and 14c are an aspect of the present invention, regardless of the type of deck or other structure that may be employed. In this regard, a particular geometry and dimensional information are used to illustrate the runner configuration according to the present invention. The present invention, however, is not limited thereto, but rather encompasses any cellular design disposed within a skin, regardless of the orientation and/or shape of the cells and regardless of the shape of the skin. For example, the present invention encompasses the cells having a tubular shape of any transverse cross section, any polygonal shape, and any combination thereof, which may be vertically or horizontally oriented. The invention encompasses cells that are not fully closed, in transverse cross section, and that employ a portion of the skin sidewall to form a portion thereof. Further, the skin may have any cross sectional shape.

[0064] Referring to FIG. 15 to illustrate another embodiment of the present invention, a steel pallet 10″ includes a deck 12 and three runners 14a′. Deck 12 is as described above with respect to the first embodiment pallet 10. Runner 14a′ includes a honeycomb support 18 that is essentially as described above with respect to the first embodiment 10, except that a substantially vertical flange 58 is disposed between the ribbon support members and honeycomb member flanges 60 (only a portion of which is shown in FIG. 15 for clarity) for welding the honeycomb support 18 to the deck 12. Further, runners 14a′ have a foot pad 62 connected to the honeycomb support 18 rather than a skin surround the honeycomb.

[0065] Because the outboard runners have the same configuration as the inboard runner in this embodiment, a C-channel 36b′ caps each opposing end of deck 12 and employs access holes 38′ as described above with respect to holes 38 in the first embodiment. Tabs 60, which may be formed on both the top and bottom portions of the honeycomb supports, may be used as a welding or fastening surface to fasten the honeycomb supports to the deck 12 and the footpad 62.

[0066] The pallet 10″, fabricated of 24 and 26 gauge sheet metal as described above with respect to the first embodiment pallet 10, has substantially the same lightweight and high strength characteristics as first embodiment pallet 10.

[0067] Regarding the exemplary pallet 10 (and 10′ and 10″), numerous variations of the structure disclosed herein will be clear to persons familiar with steel fabrication and product design. For example, particular sheet steel dimensions are provided for illustration, but the present invention is not limited thereto. Rather, the present invention encompasses a pallet described herein that is manufactured from a wide range of gauges. The pallet manufactured of steel sheet at least within the range 28 (0.015″) to 16 (0.060″) gauge may be fabricated on the same machinery as would be employed to produce the pallet of dimensions provided above. Pallets formed of steel sheet outside such a range may also be employed according to the desired loading to be used. Further, features of the embodiments may be added or omitted according to the particular design requirements. For example, apertures 31, wing 34, flange 58, tabs 60, pad 62, and numerous other features may be modified or omitted.

[0068] Particular and consistent spacing of the deck corrugations is disclosed, although the present invention encompasses employing corrugations that vary over the width of the pallet so as to provide regions thereof having relatively high strength and stiffness. Further, the invention encompasses having deck steel sheet of any thickness and corrugations of any design that may be chosen according to conventional engineering and fabricating principles to achieve the desired parameters. Also, the welds of the cellular support members to the skins and the welds of the runners to the deck may be chosen according to the appropriate design considerations.

[0069] Pallets 10, 10′, and 10″ include portions that are connected using welds. However, the present invention is not limited thereto, and encompasses fastening by any method, including for example swaging, riveting, and/or gluing, as will be understood by persons familiar with conventional fastening techniques in view of the present disclosure.

[0070] According to another aspect of the present invention, a method of processing a recyclable steel pallet is provided. A particular use or step—providing a steel pallet having a refractory material cargo—is employed to illustrate the present invention. However, the present invention is not limited thereto, but rather encompasses employing any metal pallet having the characteristics recited in the appended method claims, including steel pallet 10 and pallets 10′ and 10″ described above. For example, the pallet according to the present invention may be employed in warehouse rack and shelving systems for carrying a wide variety of cargoes. Such applications benefit from the strength and weight advantages described herein.

[0071] The present invention may also be employed for carrying raw or finished food during processing. A pallet of the configuration described with respect to pallet 10, 10′, or 10″ is well suited to such food processing applications because, for example, the cellular structure provides access to the internal portions of the runners. In this regard, eliminating the closed portions enhances the ease of sterilization (and like cleaning procedures) of the pallet.

[0072] Because pallets for food processing are typically subjected to high temperatures and must have impermeable, smooth surfaces, a pallet employed for food processing according to the present invention may be formed of stainless steel, aluminum, or like suitable metal or alloy. Because the cost of such materials may be large relative to carbon steel, the light-weight nature of the pallets and/or runners described herein may be especially advantageous.

[0073] Persons familiar with pallet design and/or conventional sheet metal product design will understand that the pallet that is employed for food processing (and the like) or rack and shelving (and the like) applications may be formed of a metal thickness chosen especially for the particular application. The material thickness, fastener or weld configurations, dimensions, and like parameters may be chosen according to conventional engineering considerations. The material of a pallet that is to be employed for a particular application may be chosen also according to conventional parameters in light of the present disclosure. Pallets according to the present invention for rack and warehouse or food processing applications are likely to be designed to be re-useable rather than being designed for a single use.

[0074] Regarding the present inventive method, a pallet, for example steel pallet 10, may be loaded with cargo at the site of a manufacturer or distributor. In the case of refractory bricks destined for an end user, such as a steel manufacturing facility, the refractory materials typically are loaded at the refractory manufacturer's site. Such a cargo may also include other refractory or related items, such as dry refractory mix or mortar, special tools, etc. Such a cargo will be referred to herein as brick or bricks for simplicity. The bricks often are arranged on the pallet so as to enhance the unloading and subsequent installation of the bricks at the end user's facility.

[0075] The present method includes receiving the bricks upon a pallet that is formed of a material that is suitable for recycling at the end user's facility. For example, for an end user that is a steel manufacturing facility or that is affiliated with a steel manufacturing facility, the pallet is formed of steel, such as pallet 10. The phrase “steel manufacturing” broadly refers to any process in which finished steel may be received and melted.

[0076] Because the pallet is destined to be recycled at the end user's facility, the pallet preferably is ungalvanized and formed of a mild steel. The pallet preferably is received without a corrosion-resistant coating, or is provided with an easily removed coating or a coating that is not detrimental to the remelt and subsequent steel making processes, as will be understood by persons familiar with such steel processing. For an end user that is a manufacturing facility of other metals, a pallet may be employed for the present invention that is formed of the particular metal that is suitable for remelting and reprocessing into other useful products or raw metal.

[0077] Upon unloading of the cargo from the pallet received by the end user, the pallet may be disposed, in the case of the user being a steel manufacturing facility, in a remelt furnace for melting. Such melting may either be in a mill that primarily recycles steel, or one that produces steel from iron ore or other raw material and is capable of mixing it with some portion of recycled steel. The step of having the pallet disposed in a steel remelt furnace encompasses the end user sending the steel pallet off the end user's site to another facility for remelting, as well as remelting at the end user's facility.

[0078] The method according to the present invention enables the steel pallet to be designed contrary to established principles. For example, even though conventional pallets are generally designed for ruggedness and long life, a pallet that may be employed by the present method, such as that described above as pallet 10, may be designed to be recycled after only a single service use. Specifically, for example, because the present method encompasses recycling by melting after only a single service (that is, for example, after a shipment of refractory bricks is transported on the pallet from the refractory manufacturer's site to the steel manufacturer's site), the pallet may be designed so as to be more lightweight than pallets designed for multiple shipments. The pallet 10 Described above is especially well-suited for such single service use at least in part because of the crushing strength provided by the skin and hex-cell construction of the runners.

Claims

1. A metal pallet comprising:

a deck, formed of a material comprising a metal, having a top surface and a bottom surface; and

a plurality of runners formed of a material comprising a metal and coupled to the bottom surface of the deck, each one of the plurality of runners including:

a skin, formed of a material comprising a metal, having a shape that is substantially box-like; and

cellular support members, formed of a material comprising a metal, being coupled to each one of the skin and the deck and disposed substantially vertically and substantially within the runner,

whereby the top surface of the pallet is suitable for receiving a cargo thereon and the runner cellular structure enhances the rigidity and strength of the pallet.

2. The metal pallet of claim I wherein each one of the deck, the skins, and the support members are formed of ungalvanized steel, thereby enabling the steel pallet to be disposed in a steel remelt furnace.

3. The metal pallet of claim 1 having a payload to pallet weight ratio of at least 1,000 to 1.

4. The metal pallet of claim 3 having a payload to weight ratio of at least 1,300 to 1.

5. The metal pallet of claim 1 wherein the deck is formed of a corrugated steel that yields under a static, semi-rigid, compressive load before the before the runners fail under the load.

6. The metal pallet of claim 2 wherein the metal pallet is formed of a material that is not the same as the material of the cargo.

7. The metal pallet of claim I wherein each one of the cellular support members is a vertically-oriented honeycomb disposed within the runner.

8. The metal pallet of claim 7 wherein each one of the honeycomb cells includes substantially continuous sides and an open top over which the deck is disposed and an open bottom beneath which a bottom portion of the skin is disposed.

9. The metal pallet of claim 8 wherein each one of the honeycomb cells is hexagonal.

10. The metal pallet of claim 8 wherein each one of the skins includes a first sidewall, a second sidewall, and a bottom member coupled therebetween.

11. The metal pallet of claim 10 wherein bottom member includes a plurality of apertures formed therein to provide access [for inspection, fumigation] to the honeycomb cells.

12. The metal pallet of claim 10 wherein the bottom members are substantially parallel to a plane defined by the deck and substantially perpendicular to each one of the first and second sidewalls.

13. The metal pallet of claim 10 wherein each longitudinal end of each one of the skins includes end flanges that at least partially retain the honeycomb within the skins.

14. The metal pallet of claim 10 wherein the cellular support members are formed by a first ribbon support member and an opposing second ribbon support member, each one of the first and second ribbon support members including an inner portion, an opposing outer portion, and a pair of oblique portions therebetween, the inner portions of the first and second support members being abutted together such that the outer portion of the first ribbon support member opposes the outer member of the second ribbon support member.

15. The metal pallet of claim 14 wherein the inner portions of the first and second ribbon support members are affixed together by welding, each one of the ribbon member outer portions and the skin sidewalls are affixed together by welding, and each one of the ribbon members is in contact with the deck bottom surface.

16. The metal pallet of claim 10 wherein each one of the skins includes a first flange formed at the top of the first sidewall and a second flange formed at the top of the second sidewall, each one of the first and second flanges being welded to a bottom surface of the deck.

17. The metal pallet of claim 16 wherein the deck is formed of corrugated steel such that a trough of the corrugations form the deck bottom surface.

18. The metal pallet of claim 17 wherein the deck is substantially continuous thereby facilitating loading of cargo thereon.

19. The metal pallet of claim 18 wherein each one of the runners defines a longitudinal centerline that is substantially perpendicular to a direction of the deck corrugations.

20. The metal pallet of claim 7 wherein the deck is formed of a corrugated steel, and the plurality of runners includes an inner runner and a pair of outer runners, the skins of each one of the outer runners having an outboard flange extending from an outboard side thereof, each one of the outboard flanges having a channel portion that is disposed over an edge of the deck.

21. The metal pallet of claim 20 wherein each one of the channels includes apertures formed on an underside thereof to enhance access to the underside of peak portions of the deck corrugations, whereby the welding together of the peak portions and a top portion of the channels may be facilitated.

22. The metal pallet of claim 1 wherein the metal pallet is employed for carrying refractory materials.

23. The metal pallet of claim 1 wherein the metal pallet is employed for warehouse rack and shelving applications.

24. The metal pallet of claim 1 wherein the metal pallet is employed for food processing applications.

25. A pallet comprising:

a deck having a top surface and a bottom surface; and

a plurality of steel runners coupled to the bottom surface of the deck, each one of the plurality of runners including:

a substantially vertical support disposed below the deck;

steel honeycomb support members coupled to the vertical support; and

a foot pad being disposed below the support members and the vertical support;

whereby the top surface of the pallet is suitable for receiving a cargo thereon and the runner cellular structure enhances the rigidity and strength of the pallet.

26. The pallet of claim 25 wherein the vertical support comprises a steel skin having a rectangular shape in transverse cross section and a pair of flanges extending outwardly therefrom, the skin being longitudinally oriented relative to the deck, the honeycomb support members being disposed substantially vertically within the skin, a bottom portion of the skin integrally forming the footpad.

27. The pallet of claim 26 having a payload to pallet weight ratio of at least 1,300 to 1.

28. The pallet of claim 26 wherein the deck is formed of corrugated steel.

29. The pallet of claim 28 wherein the corrugations of the deck yield under a static, semi-rigid, compressive load before the before the runners fail under the load.

30. The pallet of claim 26 wherein the deck is formed of a wooden sheet.

31. The pallet of claim 26 wherein the plurality of runners is galvanized, whereby the pallet is designed for multiple uses.

32. The pallet of claim 26 wherein the plurality of runners is uncoated steel, whereby the steel is in condition for recycling.

33. The pallet of claim 25 wherein the vertical support comprises a web disposed, the honeycomb support formed by a pair of opposing ribbon support members, the web being disposed between the ribbon support members.

34. The pallet of claim 33 wherein the deck is formed of corrugated steel.

35. The pallet of claim 34 having a payload to pallet weight ratio of at least 1,300 to 1.

36. The pallet of claim 35 wherein the corrugations of the deck fail under a static, semi-rigid, compressive load before the before the runners fail under the load.

37. The pallet of claim 34 wherein the deck is formed of a wooden sheet.

38. The pallet of claim 34 wherein the plurality of runners is galvanized, whereby the pallet is designed for multiple uses.

39. The pallet of claim 34 wherein the plurality of runners is uncoated steel, whereby the steel is in condition for recycling.

40. A method of processing a pallet capable of carrying various useful cargo, comprising the steps of:

receiving cargo on the pallet that is formed of ungalvanized steel and lightweight,the cargo consisting of a product that is not ungalvanized steel;

unloading the cargo from the pallet; and

disposing the pallet in a steel remelt furnace for melting of the pallet, whereby the melted pallet is suitable for making recycled steel.

41. The method of claim 40 wherein the receiving step includes receiving the cargo on the pallet that includes:

a top surface and a bottom surface; and

a plurality of runners formed of a material comprising a metal and coupled to the bottom surface of the deck, each one of the plurality of runners including:

a skin, formed of a material comprising a metal, having a shape that is substantially box like; and

cellular support members, formed of a material comprising a metal, being coupled to each one of the skin and the deck and disposed substantially vertically and substantially within the runner,

whereby the top surface of the pallet is suitable for receiving the cargo thereon and the cell structure enhances the rigidity and strength of the pallet.

42. The method of claim 40 wherein the receiving step includes receiving the cargo on the pallet that includes:

a top surface and a bottom surface; and

a plurality of runners formed of a material comprising a metal and coupled to the bottom surface of the deck, each one of the plurality of runners including:

a web, formed of a material comprising metal;

cellular support members, formed of a material comprising a metal, being coupled to each one of the web and the deck and disposed substantially, the web being disposed substantially vertically within the cellular support members, and

a footpad disposed below the cellular support members;

whereby the top surface of the pallet is suitable for receiving the cargo thereon and the cell structure enhances the rigidity and strength of the pallet.

43. The method of claim 42 wherein the disposing step includes disposing the pallet in the steel remelt furnace upon its first service or after the pallet has sustained damage to make it unfit for further service.