Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
  • B65D19/00—Pallets or like platforms, with or without side walls, for supporting loads to be lifted or lowered
  • B65D19/0004—Rigid pallets without side walls
  • B65D19/0006—Rigid pallets without side walls the load supporting surface being made of a single element
  • B65D19/0008—Rigid pallets without side walls the load supporting surface being made of a single element forming a continuous plane contact surface
  • B65D19/002—Rigid pallets without side walls the load supporting surface being made of a single element forming a continuous plane contact surface the base surface being made of more than one element
  • B65D19/0024—Rigid pallets without side walls the load supporting surface being made of a single element forming a continuous plane contact surface the base surface being made of more than one element forming discontinuous or non-planar contact surfaces
  • B65D19/0026—Rigid pallets without side walls the load supporting surface being made of a single element forming a continuous plane contact surface the base surface being made of more than one element forming discontinuous or non-planar contact surfaces and each contact surface having a stringer-like shape
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
  • B65D2519/00—Pallets or like platforms, with or without side walls, for supporting loads to be lifted or lowered
  • B65D2519/00004—Details relating to pallets
  • B65D2519/00009—Materials
  • B65D2519/00014—Materials for the load supporting surface
  • B65D2519/00034—Plastic
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
  • B65D2519/00—Pallets or like platforms, with or without side walls, for supporting loads to be lifted or lowered
  • B65D2519/00004—Details relating to pallets
  • B65D2519/00009—Materials
  • B65D2519/00049—Materials for the base surface
  • B65D2519/00069—Plastic
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
  • B65D2519/00—Pallets or like platforms, with or without side walls, for supporting loads to be lifted or lowered
  • B65D2519/00004—Details relating to pallets
  • B65D2519/00258—Overall construction
  • B65D2519/00263—Overall construction of the pallet
  • B65D2519/00268—Overall construction of the pallet made of one piece
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
  • B65D2519/00—Pallets or like platforms, with or without side walls, for supporting loads to be lifted or lowered
  • B65D2519/00004—Details relating to pallets
  • B65D2519/00258—Overall construction
  • B65D2519/00263—Overall construction of the pallet
  • B65D2519/00273—Overall construction of the pallet made of more than one piece
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
  • B65D2519/00—Pallets or like platforms, with or without side walls, for supporting loads to be lifted or lowered
  • B65D2519/00004—Details relating to pallets
  • B65D2519/00258—Overall construction
  • B65D2519/00283—Overall construction of the load supporting surface
  • B65D2519/00288—Overall construction of the load supporting surface made of one piece
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
  • B65D2519/00—Pallets or like platforms, with or without side walls, for supporting loads to be lifted or lowered
  • B65D2519/00004—Details relating to pallets
  • B65D2519/00258—Overall construction
  • B65D2519/00313—Overall construction of the base surface
  • B65D2519/00318—Overall construction of the base surface made of one piece
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
  • B65D2519/00—Pallets or like platforms, with or without side walls, for supporting loads to be lifted or lowered
  • B65D2519/00004—Details relating to pallets
  • B65D2519/00258—Overall construction
  • B65D2519/00313—Overall construction of the base surface
  • B65D2519/00323—Overall construction of the base surface made of more than one piece
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
  • B65D2519/00—Pallets or like platforms, with or without side walls, for supporting loads to be lifted or lowered
  • B65D2519/00004—Details relating to pallets
  • B65D2519/00258—Overall construction
  • B65D2519/00313—Overall construction of the base surface
  • B65D2519/00328—Overall construction of the base surface shape of the contact surface of the base
  • B65D2519/00333—Overall construction of the base surface shape of the contact surface of the base contact surface having a stringer-like shape
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
  • B65D2519/00—Pallets or like platforms, with or without side walls, for supporting loads to be lifted or lowered
  • B65D2519/00004—Details relating to pallets
  • B65D2519/00258—Overall construction
  • B65D2519/00313—Overall construction of the base surface
  • B65D2519/00328—Overall construction of the base surface shape of the contact surface of the base
  • B65D2519/00338—Overall construction of the base surface shape of the contact surface of the base contact surface having a discrete foot-like shape
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
  • B65D2519/00—Pallets or like platforms, with or without side walls, for supporting loads to be lifted or lowered
  • B65D2519/00004—Details relating to pallets
  • B65D2519/00258—Overall construction
  • B65D2519/00398—Overall construction reinforcements
  • B65D2519/00402—Integral, e.g. ribs
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
  • B65D2519/00—Pallets or like platforms, with or without side walls, for supporting loads to be lifted or lowered
  • B65D2519/00004—Details relating to pallets
  • B65D2519/00258—Overall construction
  • B65D2519/00398—Overall construction reinforcements
  • B65D2519/00432—Non-integral, e.g. inserts
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
  • B65D2519/00—Pallets or like platforms, with or without side walls, for supporting loads to be lifted or lowered
  • B65D2519/00004—Details relating to pallets
  • B65D2519/00547—Connections
  • B65D2519/00552—Structures connecting the constitutive elements of the pallet to each other, i.e. load supporting surface, base surface and/or separate spacer
  • B65D2519/00557—Structures connecting the constitutive elements of the pallet to each other, i.e. load supporting surface, base surface and/or separate spacer without separate auxiliary elements
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
  • B65D2519/00—Pallets or like platforms, with or without side walls, for supporting loads to be lifted or lowered
  • B65D2519/00004—Details relating to pallets
  • B65D2519/00547—Connections
  • B65D2519/00552—Structures connecting the constitutive elements of the pallet to each other, i.e. load supporting surface, base surface and/or separate spacer
  • B65D2519/00557—Structures connecting the constitutive elements of the pallet to each other, i.e. load supporting surface, base surface and/or separate spacer without separate auxiliary elements
  • B65D2519/00562—Structures connecting the constitutive elements of the pallet to each other, i.e. load supporting surface, base surface and/or separate spacer without separate auxiliary elements chemical connection, e.g. glued, welded, sealed

Definitions

• This invention relates to a lightweight plastic 5 pallet, in particular a pallet having integrated sheet-like pallet legs or runners.
• Pallets are included as a part of the goods that are
• Plastic pallets have the advantages over wooden pallets that they are lightweight, that they do not absorb moisture, and that they can be cleaned/disinfected, i5 which is decisive in fields where hygiene is important, e.g., in the food industry.
• EP-0 400 640 discloses a plastic pallet that is assembled from a top deck and a bottom deck with runners, or from a deck and runners. The components are
• top deck and bottom deck comprising posts and runners.
• the top deck and the bottom deck both having reinforcing ribs, are butt-welded together so that the side edges and ribs are welded together against one another.
• the plastic pallet is preferably fabricated from poly ⁇ ethylene.
• 5 Swedish Patent SE 501,539 relates to an injection molded pallet runner, preferably comprising two or three sepa ⁇ rate, hollow, closed channels along its entire length.
• the runner is lightweight, while rigid. It can be fastened by its top to suitable posts, which again are fastened to the bottom of a pallet deck.
• Prior art plastic pallets are fabricated by injection molding of components that are then joined together.
• the com ⁇ ponents will typically have reinforcing ribs at required places in order to attain a lightweight rigid construction.
• very large and expensive injection molding tools are used that require large injection molding machines having great clamping forces.
• a possible means of attaining this object is to thermofor the pallet from an extruded plastic sheet or from a parison, like the blow molding of large objects such as barrels, gasoline tanks, etc.
• To attain a lightweight and rigid construction it is often desirable to employ a coextruded multilayer structure where one of the layers is at least partially foamed.
• US Patent No. 4,874,649 discloses a method for the blow molding of a coextruded parison comprising at least two layers, one of which, perhaps more, is at least partially foamed.
• Applicant's contemporary Norwegian patent application NO-A-960128, the disclosure of which is hereby incorporated by reference, relates to a pallet manufactured by thermoforming a parison of the type disclosed in US Patent 4,874,649.
• This parison is formed into a pallet deck and spacer and runner components, which are assembled in a subsequent separate oper ⁇ ation.
• the pallet may be reinforced by introducing rigid sections into cavities formed between the pallet deck and spacers.
• the pallet's smooth and even surface makes it very simple and easy to clean and disinfect.
• the pallet is there- fore especially well suited for use in the food industry and allied industries.
• the pallet has a great strength/weight ratio because of its design. As a result, it is well suited for purposes where low weight is important, e.g. in air freight, and where manual handling of pallets occur frequent- ly.
• the present invention provides a pallet made of a thermoplastic material, the pallet comprising a deck and legs disposed underneath the deck.
• the pallet deck has top and bot ⁇ tom surfaces and a set of opposed longitudinal sides and a set of opposed transverse sides, and sheet legs integrated with the deck and disposed along at least one of said set of sides of the pallet deck.
• the pallet is fabricated by thermoforming an extruded thermoplastic parison having a monolayer or multi ⁇ layer structure into one predominantly flat article having a set of opposed longitudinal sides and a set of opposed trans ⁇ verse sides, and then bending at least one of said set of sides of the article into a position perpendicular to the main part thereof to form the sheet legs, and affixing the sheet legs into said position.
• the invention also provides a pallet, made of a thermoplastic material, comprising a deck and at least two runners disposed underneath said deck.
• the pallet deck having top and bottom surfaces, and the runners, being in the shape of a cross member having a upward-facing runner post in each end thereof, are fastened by a top surface of said runner posts to the bottom of the pallet deck.
• the pallet deck is produced by thermoforming an extruded plastic parison having a monolayer or multilayer structure into one predominantly flat article.
• the runners are produced separately by thermoforming an extruded parison identical to the one used in the produc ⁇ tion of said pallet deck into a predominantly flat article and bending the end parts of this article into a position perpen- dicular to the main part thereof to obtain the runners having upward-facing posts.
• FIG. 1 is a perspective sketch of a fabricated pallet comprising sheet legs and a leg structure consisting of block- shaped posts located in the center longtitudinally.
• Fig. 2 indicates the principle of constructing the sheet legs.
• Figs. 3 and 4 are sectional views showing alternative designs of the plate-shaped legs.
• Fig. 5 is a sectional view through the center long ⁇ itudinally of a pallet having legs consisting of deep-drawn posts.
• s Fig. 6 is a sectional view through a block-shaped pallet leg of an alternative design.
• Fig. 7 is a perspective sketch of a pallet deck and runner components prior to joining together.
• Fig. 8 is a sectional view through a part of the o pallet deck and spacer and runner components fastened to the bottom of the deck along its center longitudinally.
• Fig. 9 is a top view of a pallet where the pallet deck has raised sections.
• Fig. 10 is a side view of the pallet in Fig. 9. 5
• the present pallet is manufactured by a process that comprises a number of steps.
• the first step consists in extru ⁇ ding a parison, preferably as disclosed in the above mentioned o US 4,874,649.
• the extrudate can have various wall thicknesses around its periphery, obtained by the use of an extrusion die of a suitable configuration. Thus, different parts of the pal ⁇ let can be given different wall thicknesses.
• the extruded par ⁇ ison is flattened, and, when still hot, shaped in a mold to a 5 substantially flat article. Parts of the article can be given a desired shape, e.g. profiled structures, deep-drawn posts, etc. by utilizing combinations of compressed air and vacuum.
• a desired shape e.g. profiled structures, deep-drawn posts, etc.
• the parison In its simplest embodiment the parison consists of a homogeneous (solid) material. In order to make the extruded structure lighter, the parison can be coextruded with several layers, where at least one layer is at least partially foamed.
• Present-day coextrusion technology permits a number of options for the shape and structure of the parison.
• the extruded structure can in one specific embodiment of the in- vention consist of a foamed plastic layer having a solid skin on just one side thereof.
• the foamed layer should preferably have a closed-cell structure, however, this is not an obliga ⁇ tory feature.
• a foam having a density of down to about 100 kg/in 3 can prove useful.
• the skin will form the pal- let's outsides, so that a wear-resistant and easy-to-clean surface is attained.
• the extruded structure comprises a foamed layer having a solid skin on both sides, or optionally multiples of such a multi- layer structure.
• a foamed layer having a solid skin on both sides, or optionally multiples of such a multi- layer structure.
• the foam layer typically comprises about 70% of the sheet structure's thickness, and each skin layer about 15%, more preferably about 80% and about 10%, respecti- vely.
• the foam can have a density within the range of from the density of a solid material down to as far as it is practicable possible to pro ⁇ lou a stable polymer foam.
• Suitable materials for producing the extruded parison having a monolayer or multilayer structure comprise in prin ⁇ ciple all extrudable thermoplastics having sufficient rigi ⁇ dity.
• thermoplastics are polyolefins such as polyethylene (PE) and polypropylene (PP) , polyvinyl chloride (PVC), acrylonitrile butadiene (ABS), styrene plastics, poly- amides (PA) and polycarbonates (PC).
• polyolefin materials are preferred. However, there is nothing to prevent the foam material and the skin layer(s) from being made of different materials.
• an inside layer of high density polyetylene (HDPE) and an outside layer of ultrahigh molecular weight high density polyethylene (HMW-HDPE) and an intermediate layer of a foamed polyethylene will comprise a suited structure.
• Another structure has an inside layer of PP homopolymer, an outside layer of PP block copolymer, and an intermediate layer of foamed PP.
• other structures are also possible and fall within the scope of the invention.
• the materials constituting the solid part of the ex ⁇ truded multilayer structure can, if desired, be reinforced with cut glass fibers and/or long glass fibers in the direc- tion of extrusion.
• thermoplastics crosslinking agents in order to crosslink the material in the pallets produced.
• the disadvantage is that this kind of manu ⁇ facturing waste cannot be recycled.
• Another disadvantage is that the pallets then as a rule can be joined together only mechanically, though there do exist silane-based crosslinking agents that can be crosslinked after the finished pallet has been made.
• a friction-increasing material This can be done by extruding on the outside of the parison an extra layer with a friction material in a width from narrow strips to a continuous facing around the entire periphery of the parison 5 or around parts of its periphery.
• the friction material on the top of the pallet deck will prevent goods from sliding off the pallet, while the friction strips on the bottom will prevent the pallet from sliding easily off truck forks when the pallet is being handled.
• the friction material coating o may be applied onto the pallet deck of already fabricated pal ⁇ lets. This can easily be performed by extrusion coating, for instance by conveying the pallets underneath a stationary ex ⁇ truder in a coating line.
• the friction material is applied to the pallet in the form of parallel, raised longitudinal sections having a height of about 1 mm and in a width from narrow strips to a continuous facing.
• a suitable friction material is selected among polyolefin-containing materials such as EVA, 0 EBA and the like.
• thermoplastics such as antistatic agents, heat and UV stabil ⁇ izers, colorants, etc.
• additives and auxiliary agents that are customary for thermoplastics, such as antistatic agents, heat and UV stabil ⁇ izers, colorants, etc.
• the various layers of the multilayer 5 structure can be of dissimilar colors, as desired. It is also possible that pallets intended for dissimilar purposes can have different colors.
• the pallet deck and the sheet pallet legs along the sides of the pallet are formed in one forming step into one o predominantly flat article.
• the side parts of this article are then brought into a position perpendicular to the main sheet and fastened, e.g. by welding, in this position.
• the fastened side sheets will thus constitute one set of integrated pallet sheet legs made from the same sheet structure as the rest of 5 the article, i.e. the pallet deck.
• the pallet has sheet legs only along two opposite sides. To stabilize the legs it may be convenient to provide runners fastened to the bottoms of two corresponding opposite sheet legs. This is particularly appro- priate when the sheet legs have openings cut through their edges, e.g. three separate sheet legs along each longitudinal side of the pallet and runners fastened to the bottoms of each pair of opposite sheet legs in the transverse direction of the pallet.
• the pallet has sheet-like legs both along its longitudinal and transverse sides, and no legs in the center on the bottom.
• the sheet-like legs are joined together in the corners where they meet to obtain a rigid construction.
• the fields of use of such a pallet will normally not require any additional pallet legs.
• any combination of sheet-like legs in the longitudin ⁇ al and/or transverse directions of the pallet is contemplated by the present invention.
• additional legs intended for carrying the substantial part of the load must be provided, usually fastened to the bottom of the pallet deck at equal distances from and parallel to the sheet legs.
• Such legs may be of various constructional designs.
• Fig. 1 shows one particular embodiment of the finish ⁇ ed pallet, 1, with the pallet deck, 2, sheet legs, 3, and leg members comprising more block-shaped pallet legs, of which only one is seen in the figure.
• Fig. 2 demonstrates the principle of forming the sheet legs.
• V-shaped grooves, 5 are impressed into the sheet in its whole length in the direction of extrusion and/or in its transverse direc ⁇ tion at specific distances from the side edges of the sheet.
• These grooves are given a bottom angle of approximately 90 ° , and a suitable depth; however, the wall thickness in the bot ⁇ tom of the grooves must be sufficient to avoid that the mater ⁇ ial break during the subsequent manufacturing steps.
• the side parts, 3, of the sheet are bended along the V-shaped grooves until a position perpendicular to the main sheet and then fas ⁇ tened in this position.
• the main sheet, 2, will con ⁇ stitute the pallet deck and the side parts, 3, will constitute the sheet legs.
• the thickness of the main sheet, 2, is prefer ⁇ ably greater than the thickness of the side sheet parts, 3. This difference in thicknesses is achieved by regulating the circumferential thicknesses of the parison, as explained above, and make the final dimension adjustments in the forming tool. This thickness difference will contribute to obtain a rounded off transitional part between the pallet deck and the sheet legs.
• FIG 3 shows one em ⁇ bodiment of the sheet legs, 3, provided with approximately rectangular openings having rounded off corners. Obviously, the openings can be of any suitable shape.
• FIG 4 Another embodiment of the sheet legs is shown in figure 4, where said openings are expanded out through the bottom edge of the side sheet, resulting in three separate sheet legs, optionally two inter ⁇ spaced sheet legs.
• the desired openings in the side sheets are marked during the forming in the mold by impressing the con ⁇ tours of the openings and after the pallet has been formed the indicated parts are forced out.
• posts which will constitute one set of pallet legs are deep- drawn in the bottom of the pallet deck in its center long ⁇ itudinally and parallel to the sheet legs.
• fig. 1 only one post at one end of the pallet can be seen.
• figure 5 which is a sec ⁇ tional view which runs through the pallet at section A-A in figure 1.
• the posts, 4 can be deep-drawn in one operation to their final depths, thus constituting one set of final block- shaped pallet legs.
• such blocks may be of any shape and produced from any material, provided that they can be permanently fastened to the bottoms of the half-sized posts.
• the blocks, 6, must have such a height that they, when combined with the deep-drawn posts, 4, produce pallet legs of correct heights. The advantages of this em ⁇ bodiment is that the necessary deep-draw ratios of the posts become smaller, and the pallet legs will become stronger.
• runner component such as the one, 9, shown in fig. 7.
• This runner component consists of a cross member, 10, having two or more upward-facing posts, 11, which are fastened by their tops to the bottoms of the posts, 4, deep-drawn in the deck, 2.
• similar runner components may be fastened to the bottom surfaces of sheet legs along oppo ⁇ site sides of the pallet.
• the height of a possible deep-drawn leg structure in the center of the pallet must then be adapted to the particular design of the runner.
• Such a runner may be similar to the runner, 9, shown in figure 7.
• half-sized posts, 4, as shown in figure 6, are deep-drawn in the bottom of the deck, and the runners are fur ⁇ nished with a center post that matches post 4 of the pallet, while the posts at the ends of the runners must have a height adapted to the sheet legs, 3.
• the bottom part of the cross member of the runner component, 10 will face the floor.
• Figure 7 shows an embodiment of the pallet where a continuous U-shaped profile, 7, is thermoformed in the bottom side of the deck in the whole length thereof in its center longitudinally and parallel to the sheet legs, 3.
• the upper spacer component, 8, is fastened by its cross member, 10, to the bottom of the U-shaped profile, 7.
• the lower runner com ⁇ ponent, 9, is fastened by the tops of its posts, 11, to the bottom of the matching posts, 11, on the upper spacer compon- ent, 8.
• Each spacer and runner is manufactured in a particular operation by forming a parison into a cross member, 10, with posts, 11.
• Fig. 8 is a sectional view through the finished pal ⁇ let, 1, at section B-B in Fig. 7.
• the section runs through the pallet deck, 2, the U-shaped profile, 7, and posts, 11, on the upper spacer component, 8, and lower runner component, 9.
• the U-profile, 7, is formed into a channel, 12, and two closed hollow spaces, 14.
• the upper spacer component, 8, is shaped so that a channel formed on the top of the cross member and long- itudinally has the same width as the channel, 12, in the bot ⁇ tom of the U-profile. Consequently, a closed channel, 12, ex ⁇ tending longitudinally along the pallet is created when the pallet deck, 2, and the upper spacer component, 3, are joined together.
• the channel's length, width and depth can be made to fit the requirements.
• the U-profile, 7, and the upper spacer component, 8, are formed so that each channel, 12, is sealed at each end so that a closed hollow space is created.
• the forming can be such that the channel is open at both ends.
• the lower runner component, 9, is in principle formed like the upper spacer component, 8, but so that the cross mem ⁇ ber, 10, constitutes the surface facing the floor.
• Each post on the upper spacer component, 8, and lower runner component, 9, is formed as a symmetric profile so that two like-shaped hollow spaces, 15, and a channel, 13, are created, that will also create a closed hollow space.
• the shape of the pallet's posts can differ designwise from that sketched in Fig. 8 by variations in the dimensions of the channel, 12, and hollow spaces, 13 and 15. However, the bearing walls in the posts must be formed so that a sufficiently rigid structure is at- tained.
• a suitable stiffening section can be inserted into the channel, 12, in Fig. 8, to ensure that the pallet does not deflect at its center under great stress.
• sections made of a lightweight metal, plywood, reinforced thermoset plastics (e.g. GRP) , or other suitable plastic materials or composites are used in order to keep down the pallet' s un ⁇ loaded weight.
• pallets having sheet legs along two opposite sides may have runners fastened to the bottoms of corresponding pairs of opposite legs.
• Such runners are made by laying flat the extruded parison and shaping it into a flat, double sheet. During this forming there are impressed V-shaped grooves at a certain distance from each end, as explained above. Finally, the end parts are bent along said V-shaped grooves into a desired angle (e.g. 90 °) to the main cross member and fastened in such a position.
• Each runner is then fastened by the top surfaces of its ends to the bottoms of the appropriate sheet legs of the pallet.
• this embodiment involves a number of welding operations for each pallet: the integrated sheet legs of the pallet are fastened in their correct positions by welding, as explained above; the end parts of each runner are welded in their correct posi ⁇ tions, usually in a perpendicular position, to the cross mem- ber; and finally the runner are fastened by its end top sur ⁇ faces to the bottom surfaces of said sheet legs.
• the sheet legs of the pallet may be deleted and each runner fastened by the top surfaces of its ends directly to the bottom of the pallet deck.
• the individual components of the pallet can be join ⁇ ted together most expediently by welding, preferably by butt welding, but other methods of joining like extrusion welding, the use of glue or adhesive, and mechanically joining, can also be employed.
• the pallet deck can have a flat surface or a profiled surface. A particularly preferred embodiment of a pallet hav ⁇ ing a profiled deck is shown in figures 9 and 5.
• Fig. 9 is a top view of a pallet, 1, having channels, 16, impressed into the pallet deck, thus creating raised sec- tions, 17, running in the transverse direction of the pallet.
• Fig. 10 is a side view showing the longitudinal side of the pallet in Fig. 9.
• the dimensions of such raised sections and impressed channels i.e. their lengths, widths and heights, can be chos- en freely within the physical limits set by the extruded pari ⁇ son and the forming conditions.
• the bottom of the pallet deck may be given a similar design as the top surface of the deck, or it may be kept even.
• the raised sections in s the top and bottom surfaces of the pallet deck may run in any direction, also in different directions.
• the width of each raised section is about 35-40 mm, and the distance bet ⁇ ween any two adjacent raised sections, i.e. the width of the o impressed channels, is of approximately the same magnitude.
• the height of each raised section is about 10 mm.
• top sur ⁇ face, optionally also the bottom surface, of the pallet deck can be given any shape or design of patterns: the only re ⁇ s striction being the technical conditions mentioned above. All such designs are comtemplated by the present invention.
• Pallet decks having raised sections may provide a simplified unloading of the goods that they carry.
• the pallet indicated in Figs. 9 and 10 allows speci- o fically designed forks to be inserted into the channels in the upper pallet deck underneath the goods, which may then be re ⁇ moved as one unit from the pallet by the use of an adequate lifting device. This is particularly useful when unloading unit loads, such as goods shrink-wrapped in plastic films, 5 bottle crates, etc.
• the pallets have been explained in reference of pallets having a rectan ⁇ gular shape.
• the pallets may be of a square shape or any other suitable geometrical shape.
• references o to longitudinal sides and transverse sides of the pallet can be interchanged without deviating from the scope of the inven ⁇ tion.

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• 1996
  • 1996-03-06 NO NO960910A patent/NO960910L/no not_active Application Discontinuation
• 1997
  • 1997-01-10 CA CA 2242721 patent/CA2242721A1/en not_active Abandoned
  • 1997-01-10 WO PCT/NO1997/000009 patent/WO1997025250A1/en not_active Application Discontinuation
  • 1997-01-10 EP EP97907490A patent/EP0876284A1/en not_active Withdrawn
  • 1997-01-10 AU AU19482/97A patent/AU707915B2/en not_active Ceased
  • 1997-01-10 CN CN 97191692 patent/CN1208386A/zh active Pending

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