Patent Publication Number: US-2007107639-A1

Title: Pallet having corrugated components and modular method of making same

Description:
This application claims priority of Provisional Application Ser. No. 60/733,556, filed Nov. 4, 2005; Provisional Application Ser. No. 60/750,845, filed Dec. 14, 2005; and Provisional Application Ser. No. 60/813,893, filed Jun. 14, 2006, the disclosures of which are incorporated herein by this reference. 
    
    
     FIELD OF THE INVENTION  
      The present invention relates generally to pallets for supporting goods during handling, transportation, and storage. The preferred embodiments are corrugated paper pallets that may be made in a modular manner, and that are lightweight, capable of supporting a large weight of goods, and resistant to damage from forklifts.  
     RELATED ART  
      Traditional wooden pallets, for use in warehouses, storage yards, trucks and other modes of transportation, are well-known. Examples of wooden pallet patents include Lewis, et al. (U.S. Pat. No. 2,371,106), Eberhardt (U.S. Pat. No. 2,673,700), Woodward (U.S. Pat. No. 2,982,507), and Munroe (U.S. Pat. No. 4,240,358).  
      Wooden pallets have been in use for decades, and provide the benefits of strength and simplicity, but have the drawbacks of large weight, lack of compactness, and environmental impact due to the use of lumber. When loaded with goods, pallets are typically moved by forklift, but, when unloaded, pallets are frequently handled, carried, and stacked by hand. Wooden pallets, therefore, have been blamed for many work-site injuries due to their large weight and tendency to tip over if placed on edge. Further, wooden pallets may pose a disposal problem, frequently resulting in burning of whole pallets or pallet pieces after breakage of deck or runner members.  
      Plastic pallets have been developed, as illustrated in Brandenburg (U.S. Pat. No. 6,125,770), Ohanesian (U.S. Pat. No. 6,622,642), and Peres (U.S. Pat. No. 6,938,558). Plastic pallets tend to be complicated and expensive and to lack compactness.  
      Many pallets comprising substantial amounts of corrugated paper have been designed, as shown in Youell, Jr. et al. (U.S. Pat. Nos. Re. 35,131-5,222,444), Bridges, Jr. (U.S. Pat. No. 5,595,125), Harpman, et al. (U.S. Pat. No. 5,996,510), Rojas et al. (U.S. Publication 2004/0187745 A1), Horiuchi (U.S. Publication 2004/0237850 A1), Edell (U.S. Publication 2005/0092214 A1), and Mulcahy (PCT Publication WO 03/082688 A1). While most corrugated pallets exhibit improved performance, compared to traditional wooden pallets, in the areas of less weight and less environmental impact, prior corrugated paper pallets have tended to be complex, weak, and/or prone to damage from forklifts.  
      There is still a need for a pallet that is made substantially or entirely of corrugated paper, that is economical to make, lightweight, strong and safe in use, and that has a reasonable environmental impact.  
     SUMMARY OF THE INVENTION  
      The present invention comprises pallets and methods of making pallets, wherein the pallets are substantially or entirely corrugated material in composition. The invented pallet comprises a strong yet lightweight structure that may be made by modular methods with a minimum of components and minimum of material. The preferred pallets comprise multiple longitudinal runner assemblies, plus at least one transverse wall extending between at least two of the runner assemblies. The preferred pallets may be made entirely from corrugated paper/cardboard sheets, by scoring or marking, cutting and bending, and gluing; plastic and wood components are not necessary, but may be utilized, for example, as alternative runner structures.  
      The preferred runner assemblies comprise housings, such as sleeves or channels, and runner structures received inside the housings. Each runner structure may be elongated unitary pieces of solid, laminated, or composite material, or multiple pieces of elongated material. The runner assemblies extend in a first direction, and preferably are substantially identical, so that they may be installed interchangeably in any of the runner assembly positions. The at least one transverse wall extends in a second direction generally perpendicular to the runner assemblies. The transverse wall may be an integral portion of the top and/or bottom panel of the pallet, which is bent and glued or snapped into place.  
      In a first embodiment, the pallet comprises two housings that are spaced-apart sleeves, each of which has a rectangular cross-sectional profile, a deck (top) panel, a bottom panel, and multiple runner structures inside the sleeves. The two sleeves are preferably spaced apart to lie at the edge extremities of the pallet, where their open ends may receive the tines of a fork lift. Preferably, each one of the two sleeves will receive a two-runner set, and the two runners in each set will be spaced apart to the edge extremities of their respective sleeves. The sleeves are sized so that a central space exists between the sleeves than runs longitudinally along the pallet, and this central space may receive at least one transverse wall for reinforcement of the pallet. Therefore, the transverse wall lies generally transverse/perpendicular to the length of the pallet, to the length of the sleeves and runners, and to the planes of both the top deck panel and the bottom panel, thus, enhancing the strength of the pallet and its resistance to collapse under a load. The top panel, bottom panel, and sleeves of this embodiment may be assembled, prior to insertion of the runners, to create a pallet frame. This frame is an intermediate version of the pallet, between the initial and final stages of assembly, that may be stored flat, and, hence, that allows storage of large quantities of frame in a much smaller amount of space than would be needed for wooden or plastic pallets.  
      In a second embodiment, the pallet comprises housings that are spaced-apart channels, each of which may be called a C-shape or U-shape in cross-sectional profile, runner structures that are received in each of the channels, a deck (top) panel, and a bottom panel. In the central space between the innermost channels is received at least one transverse wall that lies generally transverse/perpendicular to the length of the pallet, to the length of the channels and runner structure, and to the planes of both the top deck panel and the bottom panel, thus, enhancing the strength of the pallet and its resistance to collapse under a load. This embodiment uses even less material and less gluing, compared to the first embodiment, to create a strong and durable pallet that is remarkably light-weight.  
      These and other features of the preferred pallets and manufacturing methods will become apparent from the following description and drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a top perspective view of one embodiment of the invented pallet.  
       FIG. 2  is a bottom perspective view of the pallet of  FIG. 1 .  
       FIG. 3  is an exploded bottom view of the pallet of  FIGS. 1 and 2 , with the pallet elements shown in bottom perspective for better viewing of the details of the bottom panel.  
       FIG. 4  is a bottom view of the pallet of  FIGS. 1-3 , with the runners shown in dashed lines as they are hidden from view inside the sleeves, and with the overlap of the sleeve edges showing through the wheel apertures.  
       FIG. 5  is a bottom perspective view of the sleeve embodiment of the pallet of  FIGS. 1-4 .  
       FIG. 6  is an end view, taken along the line  6 - 6  in  FIG. 4 , of the pallet of  FIGS. 1-5 , with the pallet resting bottom-side-up.  
       FIG. 7  is a cross-sectional view, taken along the line  7 - 7  in  FIG. 4 , of the pallet resting bottom-side-up.  
       FIG. 8  is a schematic, exploded end view of the embodiment of  FIGS. 1-7 , wherein preferred glue patterns are exaggerated so they can be easily seen in the Figure. The glue patterns preferably extend all the way along the length of the pallet (direction into the paper). The two sleeves may be identical to each other and the four runners may be identical to each other, which illustrates one embodiment of the modular nature of the preferred manufacture. The top deck and bottom deck (or top panel and bottom panel) may also be identical, except that it is preferred to cut apertures in the bottom deck for cart/jack wheels and cut securement flaps for bending and attachment to the top deck (apertures and securement flaps not shown in  FIG. 8 )  
       FIG. 9  illustrates the frame of the embodiment of  FIGS. 1-8 , the frame being made of the sleeves and top and bottom panels of the pallet of  FIGS. 1-8 , wherein the frame is collapsed for storage prior to installation of the runners and prior to gluing of the securement flaps.  
       FIG. 10  is a top perspective view of an alternative embodiment using channels rather than sleeves as housings to contain the runner structure, and using a snap-in system for fastening the securement flaps.  
       FIG. 11  is a bottom perspective view of the embodiment of  FIG. 10 .  
       FIG. 12  is a bottom exploded view of the embodiment of  FIGS. 10 and 11 , with the pallet elements shown in bottom perspective for better viewing of the details of the bottom panel.  
       FIG. 13  is an end view of the embodiment of  FIGS. 10-12 , viewed from the direction suggested by line  13 - 13  in  FIG. 10  (with the pallet resting top side up).  
       FIG. 14  is a cross sectional view of the embodiment of  FIGS. 10-13 , viewed from line  14 - 14  in  FIG. 11  (with the pallet bottom side up).  
       FIG. 15  is a partial, perspective view of a corner of the pallet of  FIGS. 10-14 , illustrating in close-up an end of one runner assembly and its relationship to the top and bottom panels of the pallet.  
       FIG. 16  is a partial, end view of the corner of the pallet shown in  FIG. 15 .  
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
      Referring to the Figures, there are shown several, but not the only, embodiments of the invented pallet. The invented pallet comprises a corrugated material and runner configuration that is particularly convenient and economical during manufacture, transport, and final assembly, and that is remarkably strong and resistant to damage from forklifts. The invented pallets are particularly effective for indoor storage and handling, however, weather-resistant coatings such as “carton coating” or covers may allow the pallets to be used outdoors at least in some climates.  
      The invented pallets comprise runner assemblies that run longitudinally along substantially the entire, or the entire, length of the pallet, and at least one transverse wall that extends perpendicularly to the runner assemblies, and that preferably extends between and contacts two of said runner assemblies. The preferred runner assemblies comprise housings and runner structures. The runner structures provide strength for withstanding the vertical load placed upon the pallet and the forces, both vertical and horizontal, that are applied during maneuvering of the pallet and goods/objects upon the pallet. The housings serve mainly to secure or at least support the runner structures in proper locations, but also provide strength to withstand said load and forces. The at least one transverse wall provides additional strength to withstand said load and forces, and is particularly effective in preventing twisting or tilting of the runner assemblies, and, therefore, in preventing collapse of the pallet.  
      The housings of the preferred runner assemblies are formed as sleeves or channels that are, either before or after receiving the runner structures, secured between the top and bottom panels to space the runner structures across the width of the pallet. The placement and spacing of said runner assemblies, and the preferred methods of securing the runner structures in said sleeves and channels, provide strength and durability with surprisingly little material and weight.  
      Referring now to  FIGS. 1-9 , pallet  100  may be described as being made of: a top panel (which is preferably but not necessarily a single solid panel), a bottom panel (which is preferably but not necessarily a single panel with four wheel apertures and optionally cut(s) for securement flap(s)), two rectangular sleeves that are received between the top and bottom panels, and four elongated runners that run parallel to each other inside the sleeves and spaced as far apart as the sleeves will allow. Several features of this embodiment combine to create a strong and durable pallet that is remarkably light-weight: the broad sleeve width, the preferred widely-space four glue patterns of each sleeve (two on top and two on bottom) holding each sleeve in between the top and bottom decks, the widely-spaced runners, and the two glue patterns for each runner (top and bottom) holding each runner in between the top and bottom sides of the sleeves. The corrugated paper frame of the pallet, without the runners, may be collapsed into a very thin and light-weight unit, which allows storage and transport of many frames in a small amount of space. The frame of the pallet may have the additional feature of a securement flap system, wherein one or more pieces of the bottom panel may be cut and folded to be vertical (during use) and to be secured to the top (deck) panel, for serving as one or more transverse walls.  
      Pallet  100  comprises a frame that is preferably made of corrugate paper (also known as corrugated paperboard, or corrugated cardboard) and which is collapsible until a plurality of runners are inserted into the frame. The runners are preferably each a single unitary piece that may be slid into sleeves as a single piece; the runners may be of various materials, such as wood, foam, molded plastic, corrugate paper, and composite materials including wood, chips, or sawdust, glue, plastics, and/or waste wood, waste plastic, or other waste or recycled materials. The frame may be made the same for embodiments receiving quite different materials and widths of runners, as long as the runners&#39; height and length are close to the height and length of the sleeves to prevent collapse or crushing of the pallet during use.  
      Pallet  100  is shown in  FIG. 1  in position to receive goods (not shown) on its upper surface  102 , formed and defined by deck panel  104 . The pallet  100  rests on its bottom panel  106 , and deck panel  104  and bottom panel  106  are separated by runner assemblies, in this embodiment sleeve assemblies  110 ,  110 ′, which preferably comprise sleeves  150  and runners  121 ,  122 ,  123 ,  124  and which serve several functions. First, the sleeve assemblies  110 ,  110 ′ may be said to give the pallet  100  a third dimension, separating the deck panel  104  and the bottom panel  106 , to provide open spaces below the deck panel  104  for receiving a forklift tines, whether the pallet is on the ground, floor, in a rack, or otherwise placed or stacked. Further, the sleeve assemblies  110 ,  110 ′ provide a rigid structure that, in effect, holds the deck panel  104  up off the ground or other object on which the pallet is set. Further, the sleeve assemblies  110 ,  110 ′ provide rigid lateral structure against which the forklift tine may abut during handling of the pallet.  
      As may be seen in  FIGS. 1 and 2 , the preferred structure results, generally speaking, in a solid, flat top surface  102 , a bottom panel  106  that has four apertures  107  to receive four pallet jack wheels and that has three securement flaps  205 ,  305 ,  405  and four “upright units” that are generally perpendicular to the deck panel  104  and the bottom panel  106 . In this embodiment, each upright unit may be said to comprise an upright corrugate sleeve portion  111 ,  112 ,  113 ,  114  and an upright runner  121 ,  122 ,  123 ,  124  adjacent to each of said sleeve portions  111 ,  112 ,  113 ,  114 . As will be discussed and called-out below, these upright units may be provided by two rectangular-cross-section sleeves  150  being placed between the deck panel  104  and the bottom panel  106 , wherein the runners are inserted into the sleeves, preferably at or near the sides of the sleeves.  
      The sleeve and runner system of the pallet of  FIGS. 1-9  greatly affects the effectiveness of the pallet and the ease and modularity of manufacture of the pallet. Each of the sleeves  150  is formed as a preferably rectangular structure, as shown to best advantage in  FIGS. 3 and 5 . Each of these sleeves  150  has a top  151 , a bottom  152 , and two sides  111 ,  112  (left sleeve),  113 ,  114  (right sleeve). Each of said sleeves  150  may be made from a single rectangular sheet of corrugate material, folded along four parallel lines to form the four corners of the sleeve  150 . The outer edges of the folded sleeve meet preferably at an overlapped seam  156  generally in the middle of the top  151  (or alternatively, the bottom  152 ).  
      Pallet  100 , in the area of the sleeves, comprises two layers of corrugate material on its bottom side ( 106 ,  152 ), wherein both layers have apertures  107 ,  117  to form holes for the pallet jack wheels. Pallet  100 , in the area of the sleeves, comprises two layers of corrugate material on its top side ( 104 ,  151 ), with a very short width of space (for example, 1-3 inches) having three layers of corrugate due to the overlap of seam  156 . One layer of corrugate ( 111 ,  114 ) forms each outer edge wall of the pallet (each outer edge wall of the pallet in this embodiment being a wall of one of said sleeves), and one layer of corrugate ( 112 ,  113 ) forms each of the interior upright walls (again, in this embodiment, a sleeve wall). See  FIG. 5 . Therefore, the regions of the pallet comprising a sleeve assembly  110 ,  110 ′ have the benefit of double layers of corrugated material on the top and bottom, and the pallet outer edge walls are walls of the sleeves rather than portions of the top deck panel or the bottom deck panel.  
      The middle region  160  of the pallet is between the left  110  and right  110 ′ sleeve assemblies, as shown to best advantage in  FIGS. 1, 4 , and  6 . Preferably this region  160  comprises no structure between the deck panel  104  and the bottom panel  106 , except for securement flaps  205 ,  305 ,  405  (discussed in more detail later in this Description), which may be cut from the bottom panel  106  or otherwise provided. Therefore, this region  160  has a single corrugate layer at its top (except for the small attachment portions of the securement flaps preferably glued to the deck panel  104 ) and its bottom, and is bound on its left and right by the upright walls  112  and  113  of the sleeves.  
      Preferably, the two sleeves  150  on the left and the right are the same in dimensions, composition, and construction, so that many sleeves may be made and installed interchangeably on either the left of the right.  
      As shown to best advantage in  FIG. 8 , the sleeves  150  are preferably adhesively attached to the bottom panel  106 , for example, by two glue patterns (G 1 ) for each sleeve at or near the upright walls  111 ,  112 ,  113 ,  114 . Likewise, the deck pane  104  is preferably adhesively attached to the sleeves  150 , for example, by two glue patterns (G 1 ) for each sleeve also at or near the upright walls  111 ,  112 ,  113 ,  114 . Conventional “cardboard glue” or other appropriate paper adhesive may be used. Each glue pattern is a long, preferably substantially continuous “stripe” of glue extending substantially all along the length of the pallet. While a bead of glue may also be effective in some embodiments, a wider pattern is preferred, such as about 2 inches wide all along its length. This may be applied by conventional means such as a roller or brush.  
      In  FIG. 9 , one may see that an intermediate version of the pallet, which typically consists of the preferred frame without any runners and without the securement flaps being glued to the opposite deck, is collapsible. The wheel apertures and the securement flaps should already be cut in the sleeves and bottom panel, the sleeves glued between the top and bottom decks (top and bottom panels), but, in the absence of the runners and the absence of gluing of the securement flaps, the frame may collapse to a very flat condition (even flatter than shown in  FIG. 9  when frames are stacked, for example). It may collapse to a thickness of about 1 inch or less (about 25% or less of a conventional rigid pallet) and has a length equal to the length of the pallet during use and a width equal to the deck panel  104  plus approximately the height of one of the upright walls  111  or  114 . The weight of the preferred intermediate version, therefore, is only the weight of the corrugate paper and is therefore only about 5-6 pounds.  
      In this collapsed configuration, many of the collapsed frames may be stacked either at the pallet manufacturer, on a truck, or at the end user, in very little space. A pallet manufacturer may make hundreds or thousands of the collapsed frames and store them easily and economically, and then be able to respond quickly to fill a large order by merely obtaining, cutting and inserting the runner material. Also, trucking of many of the collapsed frames makes economic sense, as hundreds may be stacked in a semi-tractor, whereas traditional pallets would take up too much room. For example, a trailer full of collapsed frames might hold 1500-2000 frames, and this could be trucked conveniently and economically to a distant location, whereupon lumber or other runners could be obtained (preferably locally) and inserted. Conventional pallets might only fit in a trailer in an amount of about 400, which would not justify the operation of the tractor-trailer.  
      In use, runners are inserted into the pallet frame, by sliding the runners longitudinally into their respective sleeves  150 . Two runners are installed in each sleeve  150 , one at each side near their respective upright walls ( 111 ,  112  for the left sleeve, and  113 ,  114  for the right sleeve). Preferably, no runners are installed in the middle region  160  or in any location outside the sleeves. This way, each sleeve becomes a casing or containment and support for its two runners, which are preferably approximately equal to the height of the sleeves/upright walls and preferably approximately equal in length to the length of the sleeves.  
      Glue patterns (G 2 ), such as conventional “cardboard glue” or other adhesive, may be applied to only the runner top and bottom edge surfaces (the narrow surfaces), but preferably not to the wider side surfaces, as shown in  FIG. 8 . This way, the top edge surface of each runner is glued to the top  151  of the sleeve and the bottom edge surface of each runner is glued to the bottom  152  of each sleeve, whereas the runners are not glued to their respective upright walls  111 ,  112 ,  113 ,  114 . Such a glue pattern (G 2 ), therefore, for the runners is about the size and shape of their edge surfaces, which typically will be at least 1 inch wide and the full length of the pallet. Alternatively, glue may be applied to the runner top and bottom edge surfaces and also to one side surface (facing its respective sleeve side  111 ,  112 ,  113 ,  114 ), for example. In the case of runners made of corrugate, it may be desirable to glue only the top and bottom edges, or the top and bottom edges plus one side of the runner to its respective sleeve.  
      The runners ( 121 ,  122 ,  123 ,  124 ) may be various rigid and strong materials, such as wood, dense foam, plastic, or even laminated/layered corrugate. For example, runners may be nominal 1×4 inch lumber. Alternatively, runners may be nominal 1×4 inch “corrugate board” made of 4 or more layers of corrugate glued together, with the planes of the layers being vertical (up and down in  FIGS. 3 and 8 ). The preferred runners are rectangular in cross-section; other sizes, shapes, and materials may be used. In the embodiment of  FIGS. 1-9 , each runner is preferably a pre-formed or pre-cut unitary piece that may be slid into the frame after the frame is formed (after the top and bottom decks are attached to the sleeves), as opposed to a single piece or multiple pieces that are installed or layered into the sleeve prior to forming the frame.  
      The preferred corrugate paper for the pallet is: 200 lb bursting strength, single wall corrugate for the bottom panel  106  (although double wall or two single wall panels may be used); 200 lb bursting strength double wall corrugate for the deck panel  104  (although additional layers may be used); and 200 lb bursting strength, single wall corrugate for the sleeves  150 . Other corrugate may be used, as desirable for strength or customer preference.  
      A fully-assembly pallet with 1×4 inch (nominal) wooden runners will weigh approximately 14 pounds, while a conventional all-wood pallet may weight 30-35 pounds. Even with this greatly-reduced weight, the preferred pallet exhibits surprising strength; the inventor envisions that the preferred pallet may hold up to at least 1000 pounds, for example. The preferred pallets are rackable in conventional pallet racks, are stackable, and easily handled by a worker with little chance of injury.  
      The two sleeve regions and the middle region combined extend across the entire width of the pallet. Each sleeve region takes up preferably about 35-40% of the width of the pallet, for a total of the two sleeve regions forming about 70-80% of the width, and the middle region  160  taking up the remaining 20-30% of the width. For a 40 (width)×48 inch (long)×4 inch (high) standard-size pallet, the sleeves are each approximately 13-16 inches wide (totaling 26-32 inches), leaving approximately 8-14 inches for the middle region. The especially preferred sleeve widths are 15 inches each, which leaves a middle region of 10 inches in a 40 inch wide pallet. The 15 inch wide sleeves allow for widely-spaced runners across the width of the pallet, plus enough room for the forklift tines to enter the sleeves between each sleeve&#39;s two runners and enough room for the pallet jack wheels to extend up into the holes. Note that the sleeves as well as the bottom panel have apertures  107 ,  117  for the wheels.  
      The configuration and spacing of the preferred sleeves and runners, and their preferred glue patterns, result in a surprisingly strong and durable device. The preferred pallet is remarkably strong when holding downward force on the deck panel  104  from a load of goods, and is remarkably durable under the forces exerted by a conventional forklift. Many conventional pallets are broken by forklifts, especially when the forklift turns more tightly than is optimal when lifting a loaded pallet. During this event, the tines of the forklift pivot in the internal spaces of the pallet to tap or gouge into the runners/walls of the pallet at one or both ends of the tines. The resulting leverage often breaks the runner or walls or pops a runner out of the pallet. In the preferred embodiments of the invention, on the other hand, the spaces for receiving the tines are large, and each sleeve unit acts as a whole to retain and secure the sleeve and its runners in the pallet. The forces trying to “pop” a runner out of the pallet through the side edges of the pallet are resisted by the glued-in runners (with glue pattern all along their lengths on top and bottom and preferably at least ¾ inches wide), and by the glued-in sleeve (with glue pattern all along their lengths and preferably two glue patterns each on top and bottom, ¾-2 inches wide, and spaced about 15 inches apart). Thus, it is unlikely the tine can pop the entire sleeve unit out of the pallet and it is unlikely to maneuver into a pivoted position wherein it could break a runner in two. While other pallet dimensions may be used, especially different lengths, the same general principles apply. One may note that the preferred pallet has forklift tine access spaces only on two edges/sides of the pallet, rather than on all four. This also provides additional strength and durability to the pallet, for example, helping prevent breakage of any of the runners by the tines.  
      While other features may be added, preferred embodiments of the general type represented by  FIGS. 1-9 , are simple and modular in construction, and may consist only of or consist essentially of: a deck panel, a bottom panel, two sleeves, and four preferably insertable runners. Each sleeve may be so simple as to consist only of or consist essentially of: a rectangular cross-section elongated structure with an empty interior (except for two runners in each sleeve). The pallet may be made without fasteners except for adhesive. The pallet frame may be recyclable, and the runners may be made from waste materials and/or may be reusable past the life of the corrugate frame.  
      In alternative embodiments, the same corrugate frame may be used as is shown in  FIGS. 1-9 , but nominal 2×4 inch lumber may be used for the runners. These runners have the same height (nominal 4 inches), but a greater width (nominal 2 inches). This will serve to increase strength and durability even more, as may be desired for some goods that will be carried and stored on the pallets. While the two nominal 1×4 inch runners take up about 1¾ inches of the width of each sleeve, the two nominal 2×4 inch runners take up about 2½ inches, in both cases leaving the great majority of the sleeve interior space open. Thus, the preferred runners may fill about 10-20% of the width of the sleeves, leaving 80-90% empty, and still provide the required strength and durability. One may note that, partly because of the dimensions of the runners (being approximately the same height as the interior space of the sleeve—nominally 4 inches but actually approximately 3¼-3½ inches) and because of the adhesive holding the edge surfaces of the runners to the top and bottom  151 ,  152  of the sleeves, the runners are very unlikely to rotate on their longitudinal axis and will stay in the proper upright orientation even under substantial force. While adhesive on the side (broader) surfaces of the runners contacting the upright corrugate walls ( 111 ,  112 ,  113 ,  114 ) may be beneficial in some cases for preventing runner rotation, it has not been found to be necessary, and, hence, is not preferred as it would increase the cost and steps of manufacture.  
      Yet other embodiments of the pallet may use polyethylene foam runners inserted into the frame. The preferred foam is dense and firm foam that provides the required runner strength, but has some small amount of resilience that may allow the runners to be inserted and held in the frame without adhesive. These foam runners may be formed slightly taller than the wooden runners, for example, a full 3½ inches (actual rather than nominal), so that the foam runners fit snugly, and even compress slightly, when installed in the frame. The foam runners are preferably a full 2 inches wide, giving these un-glued runners more stability in the sleeves to prevent their tipping/rotating on their longitudinal axis. The foam-runner version of the pallet may be very light weight, for example, about  8  pounds per pallet, and may be excellent for carrying lighter goods.  
      In the preferred embodiments of the invention, at least one transverse wall is provided for cooperation with the longitudinal runner assemblies for providing further collapse- and crush-resistance to the pallet. Many different transverse walls may be used, but the preferred transverse wall comprises at least one, and preferably 2-4, securement flaps cut from the top deck panel or bottom deck panel; this technique is especially efficient, as no extra material need be added other than what is used in embodiments without such flaps, except for a very slightly increased amount of glue in some instances. Preferably, the securement flaps are spaced out along the middle region to maximize the strength of the pallet.  
      The securement flaps of pallet  100  will now be described in detail. In the embodiment of  FIGS. 1-9 , there are three securement flaps  205 ,  305 ,  405 , with two ( 205 ,  405 ) being at opposing ends of the pallet, and one being in the middle ( 305 ). A piece of the bottom panel at each end of the pallet is folded up and inward toward the center of the pallet and attached to the deck panel about 5 inches in from the edge of the pallet. A third piece of the bottom panel near the center of the bottom panel is folded up and attached to the deck panel. This way, the main portion of each securement flap is generally vertical when the pallet is in use, extends substantially all the way between the sleeve units (preferably, all the way, to contact the sleeve units), and serves to make the pallet extremely strong and rigid during use, without adding any weight except a few grams of glue. The flap system need not attach to the sleeve units, and it prevents or helps prevent lateral movement of the sleeve assemblies, collapse of the sleeve units, and collapse of the entire pallet. The two folds (one between the main flap panel  206 ,  306 ,  406  and the bottom panel  106  and one between the main flap panel  206 ,  306 ,  406  and the glue tab  207 ,  307 ,  407 ) of each of the flap systems need be the only “transverse” folds in the pallet. All the others folds of the preferred embodiments are longitudinal, as may be noted from the other description and drawings (longitudinal being the direction up and down on the paper in  FIG. 4  and into the paper in  FIG. 8 , for example).  
      Referring especially to  FIGS. 2-4  and  7 , flaps  205 ,  305 , and  405  are shown to best advantage. Each flap  205 ,  305 ,  405  has a main flap panel  206 ,  306 ,  406  that extends generally transverse to the length of the pallet and also perpendicular to the deck panel  104  and to the bottom panel  106 . The main flap panels  206   306 ,  406  each extend between the deck panel  104  and bottom panel  106  substantially all the way between the sleeve assemblies  110 ,  110 ′.  
      Preferably, each end flap  205 ,  405  is cut from the bottom panel  106 , by making two longitudinal cuts (about 5 inches) into the bottom panel in between where the two sleeve assemblies  110 ,  110 ′ will be/are glued. The central flap  305  is cut from of the bottom panel  106  by making two longitudinal cuts (about 5 inches) and one transverse cut between said longitudinal cuts. Each flap  205 ,  305 ,  405  is then bent at about its 5 inch mark to form the bend between the bottom panel  106  and the main flap panel  206 ,  306 ,  406 , and then at about 1½ inch from the end of the flap  205 ,  305 ,  405  to create a glue tab  207 ,  307 ,  407  on each flap. Thus, two longitudinal cuts are made for each flap  205 ,  305 ,  405  in order to allow the two folds transverse to the length of the pallet, and these two folds form the main flap panels  206 ,  306 ,  406  and the tabs  207 ,  307 ,  407  of each flap  205 ,  305 ,  405 . The flap is then folded up toward the deck panel  104  (“down” toward the deck panel  104  if the pallet is in the bottom-up orientation of  FIGS. 2, 3 , and  7 ) and the glue tab  207 ,  307 ,  407  is folded to be parallel to and glued to the underside of deck panel  104 .  
      In order to maintain compact, collapsed storage of the frames of the pallets (that is, the sleeves plus the deck (top) panel and bottom panel, without the runners, of the embodiment of  FIGS. 1-9 ), the gluing of the securement flaps may be postponed until set-up of the pallet and insertion of the runners. In other words, gluing the securement flaps works to keep the pallet in an un-collapsed condition, so, while the securement flaps may be cut, and even folded, at the time of the other forming of the bottom panel, said gluing should not be done until a fully-set-up and functional pallet is desired.  
      Preferably, flaps ( 205 ,  405 ) are provided at both ends of the pallet, wherein the cuts and folds are orientated so that the flaps bend in toward each other (toward the center of the pallet). The central securement flap ( 305 ) may be cut and bent either direction (toward either end of the pallet), but, preferably, the cuts and bend for this central securement flap  305  are positioned so that, once the flap is bent and glued to the deck panel, the main flap panel  306  is centrally located in the middle region, that is, about equidistant between the ends of the pallet. Because the central flap  305  typically extends all the way between sleeves of equal widths, the central flap main flap panel  306  will tend to be centered between the sides and the ends of the pallet, that is, truly centered in the panel. This symmetry is not always necessary, but is preferred.  
      The combination of two end securement flaps and a central/centered securement flap provides extra rigidity and strength to the pallet and assuring that the pallet will not collapse when fully assembled. Other orientations, numbers, shapes, and sizes of secruement flaps may be used. For example, less-preferably, securement flaps may be portions of the deck panel extending toward and attaching to the bottom panel. Less-preferably, flaps may be additional, separate pieces of material that extend between and attach to the deck and bottom panels. Other reinforcements, such as a block, box, or other three-dimensional object(s) may be added to the pallet to provide said at least one transverse wall, but the preferred transverse wall is simply a sheet, portion of a sheet, or flap of corrugated material, or other substantially two-dimensional wall, as simplicity and low weight are goals for the transverse wall.  
      Referred now to  FIGS. 10-16 , there is shown a pallet embodiment featuring alternative runner assemblies and modified securement flaps. Pallet  500  comprises top panel (or “top deck”)  504 , bottom panel (or “bottom deck”)  506 , and multiple runner assemblies  510  that provide upright units between said top and bottom panels that are spaced across the width of the pallet. Each runner assembly  510  in this embodiment comprises what may be called a C-shaped or U-shaped channel  512 , said channel having an upright wall  511  and a top extension  551  and a bottom extension  552 . Together, these three portions of the channel  512  form an interior trough space that contains additional reinforcement structure. The additional reinforcement structure may be a runner structure of various materials, and, most preferably, it is a corrugate runner structure  515  comprises layers of corrugated material (strips  521 ) parallel to each other and parallel to said upright wall  511 .  
      Four of said assemblies  511  are spaced apart across the width of the pallet  500 , with the two left assemblies facing each other so that the channels  512  open toward each other, and the two right assemblies also facing each other so that the channels open toward each other. The upright wall  511  of the farthest-left channel serves as one outer edge wall (left edge wall) of the pallet, and the upright wall  511  of the farthest-right channel serves as the other outer edge wall (right edge wall) of the pallet.  
      The channels  512  each may be made from a die-cut, elongated sheet of corrugated cardboard, scored longitudinally at two locations to mark the transition from upright wall  511  to top and bottom extensions  521 ,  522 . Glue may be rolled along the length of the sheet preferably at four locations, that is, one on each side of said two scorings. The sheet is then bent at said scorings around a stack of parallel elongated strips  521  so that the planes of the strips are parallel to wall  511 . The strips  521  preferably consist of four strips of double-wall corrugate, but more than four strips may be used for stronger pallets. Double-wall corrugate is preferred because the strips may be easily die-cut, as opposed to the sawing that may be required for triple-wall corrugate. The elongated glue patterns (each “stripe” of glue preferably being about ¾ inches wide) attach the channel  512  to at least some of the strips, specifically, two glue stripes adhesively attach to the strip that lies against the wall  511 , one stripe adhesively attaches to the top edges of at least some of the strips  521 , and one stripe adhesively attaches to the bottom edges of at least some of the strips. Preferably the strips  521  are not glued or otherwise fixed to each other; instead, they stay in place inside the channel because of the channel serving as a housing that is located and glued (to at least some of the strips) around three sides of the assembly of strips  521 .  
      Alternatively, each channel  512  may receive a runner that is a unitary piece, rather than a stack of strips as described above. Such unitary-piece runners may be wood, plastic, composites, or other single-piece runners.  
      Pallet  500  includes at least one, and preferably three, transverse walls, which take the form of securement flaps  555 ,  556 ,  557 , which, in combination with the longitudinal runner assemblies, provide a very strong, yet lightweight reinforcement system for the pallet. The securement flaps  555 ,  556 ,  557  are cut from the bottom deck panel, and no extra material need be added to the pallet to form the flaps  555 ,  556 ,  557 .  
      Securement flap  555 ,  557  are, therefore, pieces of the bottom panel at each end of the pallet that are folded inward toward the top panel of the pallet, and attached to the top panel about 5 inches in from an edge of the pallet. Securement flap  556  is a third piece of the bottom panel near the center of the bottom panel that is folded up and attached to the top panel near the center of the top panel. This way, the main portion of each securement flap is generally vertical when the pallet is in use, extends substantially all the way (preferably, all the way) between the two central runner assemblies  510 , and serves to make the pallet extremely strong and rigid during use, without adding any weight. The flaps need not attach to the runner assemblies  510 , and they prevent or help prevent lateral movement of the runner assemblies  510 , collapse of the assemblies  510  and collapse of the entire pallet.  
      The flaps  555 ,  556 ,  557  each include only one fold (between the flap and the bottom panel, and it is these folds of the flaps that need be the only “transverse” folds in the pallet. All the others folds of the preferred embodiments are longitudinal, as may be noted from the other description and drawings (longitudinal being the direction into the paper in  FIG. 13 , for example).  
      Preferably, each end flap  555 ,  557  is cut out of the bottom panel  506 , by making two longitudinal cuts (about 5 inches) into the bottom panel in between where the two innermost runner assemblies  510  will be/are glued. The central flap  556  is cut from of the bottom panel  506  by making two longitudinal cuts (about 5 inches) and one transverse cut between said longitudinal cuts. The outer, free ends of each flap  555 ,  556 ,  557  are formed to have preferably one, or optionally more, tabs  570  protruding slightly from their adjacent edges, and, upon bending the flap  55 ,  556 ,  557  relative to the bottom panel  506 , these tabs  570  are snapped into slots  580  provided in the top panel  504 . Thus, the flaps  555 ,  556 ,  557  do not require any glue or attachment other than the tabs  570  being engaged in slots  580 .  
      Preferably, end flaps  555 ,  557  are provided at both ends of the pallet, wherein the cuts and folds are orientated so that the flaps bend in toward each other (toward the center of the pallet). The central flap  556  may be cut and bent either direction (toward either end of the pallet), but, preferably, the cuts and bend for this central securement flap  556  are positioned so that, once the flap is bent and snapped into the deck panel, the central flap  556  is generally centrally located in the middle region, that is, about equidistant between the ends of the pallet. Because the central flap  556  typically extends all the way between runner assemblies  510  of equal widths, the central flap  556  will tend to be centered between the sides and the ends of the pallet, that is, truly centered in the panel. This symmetry is not always necessary, but is preferred.  
      The combination of two end securement flaps and a central/centered securement flap provides extra rigidity and strength to the pallet and assuring that the pallet will not collapse when fully assembled. Other orientations, numbers, shapes, and sizes of secruement flaps may be used. For example, less-preferably, securement flaps may be portions of the deck panel extending toward and attaching to the bottom panel. Less-preferably, flaps may be additional, separate pieces of material that extend between and attach to the deck and bottom panels. Other reinforcements, such as a block, box, or other three-dimensional object(s) may be added to the pallet to provide said at least one transverse wall, but the preferred transverse wall is simply a sheet, portion of a sheet, or flap of corrugated material, or other substantially two-dimensional wall, as simplicity and low weight are goals for the transverse wall.  
      Once the top panel is cut into the desired form (including slots  580 ), the bottom panel is cut into the desired form (including apertures  507  for receiving wheels, and securement flaps  555 ,  556 ,  557 ), and the runner assemblies  510  are formed, the pallet assembly may be finished. One will note, however, that, the top panel, bottom panel, and assemblies  510  may be transported and stored in a compact configuration, until final assembly is desired. For example, many top and bottom panels may be stacked, and many runner assemblies  510  may be nested together with little empty space between them.  
      To complete assembly of the pallet  500 , longitudinal glue stripes are rolled in four places along the underside of the top panel  504 , the four assemblies  510  are set on said glue stripes, and then the bottom panel  506  is glued to the four assemblies  510 . The glue attaching the bottom panel  506  to the assemblies  510  may be placed on extensions  522  or on the bottom panel  506 . The pallet may then be compressed slightly to ensure good adhesion of the glue. Flaps  555 ,  556 ,  557  are then folded toward the top panel and their tabs  570  snapped into slots  580 .  
      Thus, the especially-preferred pallet  500  comprises minimum material, and very light weight material. The inventor prefers pallet  500 , because he has reduced the sleeve material of pallet  100  to two channels  512  in pallet  500 , and he has provided multiple layers or strips  521  of corrugated material instead of solid wood or plastic runners. Pallet  500  is surprisingly durable and strong, for example, capable of carrying  1000  pounds or more or weight, while preventing many accidents and injuries that happen during use of traditional wood pallets.  
      While other features may be added, preferred embodiments of the pallet are simple and modular in construction, and may consist only of or consist essentially of: a deck panel, a bottom panel, two sleeves or four channels, and four preferably insertable runners or four assemblies of strips to serve as runner structures. Each sleeve may be so simple as to consist only of or consist essentially of: a rectangular cross-section elongated structure with an empty interior (except for two runners in each sleeve). Each channel may be so simple as to consist only of or consist essentially of: an elongated rectangular three-sided member, open at one side. The pallet may be made without fasteners except for adhesive and optional snap-in or snap-together means. The pallet may be recyclable, with the runners recyclable or reusable.  
      Preferred embodiments of the invented pallet may be described as being for holding objects up off of a supporting surface, wherein the pallet comprises: a top panel; a bottom panel; a plurality of runner assemblies between said top panel and bottom panel, wherein each of said runner assemblies comprises a housing extending along substantially the entire length of the pallet and having at least three sides comprising a vertical side wall, a top wall connected to the top panel, and a bottom wall connected to the bottom panel, and wherein each of said runner assemblies further comprises a runner structure received in said housing and extending along substantially the entire length of the pallet between said top wall and said bottom wall; and at least one transverse wall extending between the top panel and the bottom panel in a region of the pallet distanced from the outer perimeter of the pallet, said at least one transverse wall being perpendicular to said runners and perpendicular to said top panel and said bottom panel. Preferably, the runner assembly, the housing, and the runner structure extend along at least 80 percent, and more preferably, along at least 90 percent, of the length of the pallet. The pallet at least one transverse wall may be a portion of said bottom panel, folded to be perpendicular to the bottom panel and reaching to said top panel, for example. The pallet at least one transverse wall may be a portion of said top panel, folded to be perpendicular to the top panel and reaching to said bottom panel, for example. The pallet may include two of said transverse walls near ends of the pallet and one of said transverse walls generally centered in the pallet, for example. Said at least one transverse wall may have a tab at its distal extremity and said at least one transverse wall may connect to the top panel by said tab being received in a slot in said top panel. Said pallet may have a top surface which is the outer surface of said top panel, and said tab, for example, may extend into said slot but not out from said slot to extend beyond outer surface of the top panel. Said runner assembly housing, for example, may be a four-sided sleeve that is rectangular in cross-section, and that extends the entire length of the pallet, and said runner may be a separate unitary piece that is slidable into said sleeve. Said runner assembly housing, for example, may be a three-sided channel that extends the entire length of the pallet, and said runner may be a separate unitary piece that is slidable into said sleeve. Said runner assembly housing, for example, may be a three-sided channel that extends the entire length of the pallet, and said runner may comprise multiple strips of corrugated paper each having a plane, said strips being received inside the channel so that their planes are perpendicular to said top panel and said bottom panel. Regarding the multiple strips, it may be that none of the multiple strips are glued to each other. The runner assembly may extend, in some embodiments, continuously along substantially the entire length of the pallet, that is, without interruptions. The housing may extend, in some embodiments, continuously along substantially the entire length of the pallet, that is, without interruptions. The runner structure may extend, in some embodiments, continuously along substantially the entire length of the pallet, that is, without interruptions. In many embodiments, the pallet includes no tubular runners, and, in many embodiments, the pallet includes no tubular members at all.  
      An especially-preferred embodiment comprises four of said runner assemblies, wherein each of said housings is a rectangular channel open on one side and defining an interior space, the interior space receiving said runner structure, wherein portions of said channel are glued to said runner structure, and wherein a first two of said four runner assemblies are a left set positioned between said top panel and said bottom panel near a left edge of the panel wherein the channels of said left set open toward each other. In the especially-preferred embodiment, a second two of said four runner assemblies may be a right set positioned between said top panel and said bottom panel near a right edge of the panel wherein the channels of said right set open toward each other.  
      As an important feature of many embodiments is the simplicity, economy, and ease of manufacture, the pallet may consisting essentially of, or consist of: a top panel; a bottom panel; a plurality of elongated runner assemblies between said top panel and bottom panel, each runner assembly extending along substantially the entire length of the pallet, wherein each of said runner assemblies comprises a housing extending along substantially the entire length of the pallet, the housing comprising a three-sided channel including a vertical side wall, a top wall connected to the top panel, and a bottom wall connected to the bottom panel; and the runner assemblies further comprising runner structure received in said housing and extending along substantially the entire length of the pallet between said top wall and said bottom wall; and a plurality of securement flaps extending between the top panel and the bottom panel at locations in the pallet distanced from the outer perimeter of the pallet, said securement flaps being perpendicular to the length of said runner assemblies and perpendicular to said top panel and said bottom panel. Said securement flaps may be portions of the bottom panel that fold to be perpendicular to the bottom panel and said securement flaps may have a distal end that attaches to the top panel. Said securement flaps may be portions of the top panel that fold to be perpendicular to the top panel and said securement flaps may have a distal end that attaches to the bottom panel. Said securement flaps each may have a distal edge and a tab at said distal edge, and said top panel may comprise a plurality of slots that receive said tabs to secure the flaps in position perpendicular to said top panel and bottom panel. Said runner structure may comprise multiple sheets of corrugated material positioned to be parallel to said vertical wall of the channel. In some embodiments, at least some of said multiple sheets are glued to said channel but not glued to each other. In some embodiments, said top wall and bottom wall of said channel extend beyond the multiple sheets of corrugated material.  
      Although this invention has been described above with reference to particular means, materials and embodiments, it is to be understood that the invention is not limited to these disclosed particulars, but extends instead to all equivalents within the broad scope of the following claims.