DE1628959A1 - Wooden panel construction - Google Patents

Description

DR.-ING. DIPL-ING. G. RIESLING 1628959 PATENT ADVOCATE My sign , .

B 323 Fri / school / room

Please · Repeat in the answer

899 Lindau (Bodensee) Your · Message from My message from Rennerle 10 P.O. Box 365

January 15, 1968

Broiunline Corporation, 2500 Compton Blvd., Redondo Beach, California 90278 / USA

Improved wood panel construction.

aa

eaa includes the application of a compressive force to the surfaces of a multilayer wood board above the crush limit of the multilayer wood board and below the force at which the board is destroyed in order to substantially weaken it, to constantly increase its thickness.

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Telegraph: Office hours Bank account: Postal checking account:

06 4374 patent d by agreement with Bayer. Staatsbank Lindau (B) No. 15 «Munich 29S2S

reduce and die-density of the core of the multilayer Raise wooden panel. The compressive force is along a Preselected area applied, such as an edge part of the multilayer wood panel, around it Reduce thickness while allowing the thickness of the remaining part of the wood panel, essentially unchanged to remain. The part of reduced thickness is contiguous with the rest of the wood panel by one tapered transition part connected. A suitable accessory such as an edge part, or a ver- binding part is then attached to the edge around the same to protect and increase its strength. DxB wood panels are used for various purposes such as pallets.

Pallets of the type used, for example, to transport cargo in airplanes often made of one or more plate parts. If more than one plate part is used, the adjacent plate parts connected to one another along their adjacent edges by a connecting part. Pallets are handled very roughly and not uncommon

the equipment handling the cargo is damaged and causes vigorous pushing of the pallet. As a result, it is common practice to attach an edge piece to the perimeter of the pallet, to protect the edge of the pallet and the strength of the Range to increase.

The connecting parts are typically H- or double-T-shaped in cross-section, with each of the channel parts having an edge part of the wooden plate encloses * In the same way are the Edge parts U-shaped in cross section and enclose the outer edge of the wooden board,

The panels are typically multi-layered and contained a core with outer layers on opposite sides Outside surfaces of the core are glued. It is necessary or desirable to have edge parts and connecting parts at least with one face of the plate to which it is attached are to be made flush «This is necessary to allow the pallet to have a set of pallet receivers Rolls to be moved, like them for example used in the floor structures of aircraft are j without hitting the edges of the connecting parts. To this feature of flush. Fixation to be provided, it is necessary along the edge parts of the panels

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to form a groove. With previously known methods this groove is formed by milling out an edge part of each wooden panel. The milling process removes one Edge part of one or both of the surface coatings

5 ". Of the multilayer wooden board and part of dBS of the Coating of the neighboring core. This loss of material results in a substantial reduction in pallet strength. Since pallets are subjected to very rough handling, this lower strength reduces the service life of the

ι Palette very important.

The pallet strength is also reduced by the fact that the milling creates a notch in the plate. the Notch creates stress concentrations when using the dBr pallet, increasing the possibility of damage to the pallet.

In previously known methods, a Edge part attached to the core, with the end faces of the edge part abut the notch in the core. During use, those adjacent to the notch tend to be Surface coating and the core to separate from each other, or from the end faces of the edge— partly üjegzübrechen. This further weakens the construction

162B959

and lays the wood of the core fell, allowing it to absorb moisture. These factors decrease the Lifetime of the pallet,

According to the present invention, the thickness of the edge portion of the wooden board is reduced without its strength essentially, to influence. Thus the strength is of the relatively thin edge portion approximately equivalent to the strength of the rest of the pallet. The cowardice The pallet manufactured according to the teaching of the present invention is then used, you keep the " Notching the wooden top and using a tapered one Transition part between the thick and the thin Part of the wooden panel. Is part of the present invention it doesn't need to be part of any of the outer layers remove to reduce the thickness of part of the wood panel. Accordingly, the edge part or another may Accessory to be attached to the plate * where the Accessory the edge parts of the surface coatings encloses. By not removing the surface coating the strength of the pallet is further increased and [.the " As discussed above, the dependency of the external authorities Layer and moisture absorption are essential

. switched off. "■

The present invention is for wood panel construction applicable and especially for multilayer wood panels, such as those used for the manufacture of pallets will. A multilayer wooden board contains a core with generally opposing faces and first and second surface coatings that coincide with the opposite Surfaces of the core connected or otherwise attached to it. The present invention is Applicable to various materials, but is particularly suitable for cores made of wood such as Plywood or balsa wood and for surface coatings made of metal, such as aluminum sheet, or a hard plastic material such as phenolic resin.

A basic idea of the present invention is to preselect the thickness of a multilayer wood panel in a Area by applying a compressive force to the wood panel above the press line of the layered To reduce wooden panel, but below the force, in which the plate is destroyed, but in the substantial tapers to allow for the attachment of a Accessories on the selected thinner area too

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facilitate. This results in a permanent reduction in the Thickness and an increase in the density of the core and the multilayer wood panel. By following this procedure the force required is necessary to break it such a pressed wood panel performs as it does a simple bar experiment is approximated equivalent to the force required to break the same wood panel performs when their thickness is not as taught herein through Compression of the wooden plate ^ has been reduced. Therefore, one according to the teachings of this invention resists Pressed multilayer wood panel of a larger size load, without structural damage, than a corresponding non-pressed wood panel of the same materials and a thickness that the original thickness is equivalent to the pressed wood panel. ;

With the pallet construction and some other exen '. Construction types is. the pressed selected area an edge part the multilayer wood board and the edge part or connecting part (herein generally as accessories designated) have a U-shaped part, the encloses the pressed edge part. The edge parts: the Surface coatings are also included in the accessory ^ to increase the strength of the wooden plate and

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to prevent the surface from peeling off. The amount of the Pressure is preferably sufficient to allow the accessory to to be attached substantially flush with the adjacent surface of the wood panel. Of course it is present invention is not limited to pallet construction as it is generally advantageous in a Wood panel to provide an area of reduced thickness to accommodate various shapes of accessories. In the same way, the pressed area does not need a To be the edge area of the wood panel.

The core can be applied before the surface coatings are applied be pressed against it, in which case the force applied must exceed the pressing limit of the core alone. This last © procedure has the advantage of less force to need to press the wooden plate, since the pressure limit of the core alone is visibly lower than that Press limit of the entire multilayer wood panel. However, it is preferred to complete the pressing process multi-layer wood panel after the surface coatings are attached to the core. In in this case the force applied must exceed the press limit the multilayer wooden board top to the board continuously deform to a thickness less than

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ORIGINAL INSPECTED

the original thick © of the multilayer heating plate.

The maximum applied to the multilayer wooden board Strength should: not exceed the strength, with softer the Wood panel structurally destroyed and essentially weakened urird. For example, if the core is made of balsa wood is made, the maximum pressing force is softened, when the core becomes damaged as a result of the thrust. In in the same way, it is assumed that other materials if they are pressed enoughy eventually structurally destroyed and 'essentially weakened murder. For certain (materials, however, this is a theoretical one Limit, as it is possible, very substantially without regard to press on the upper limit "of the compressive force"

The present invention also teaches that it is necessary To initially press the wooden panel more than desired, due to the inherent property of the material known as rebound, i.e., the inclination of the pressed lYIaterials to enlarge its thickness as soon as the Pressing force has been removed. The size of the initial reduction in thickness must be up to 50% greater than the desired size of the reduction in order to prevent the spring back. compensate. The amount of springback is mainly due to *

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mainly on the core density and the moisture content, the thickness and tensile strength of the surface coatings and the size of the pressing force.

In order to avoid breaking the materials of the multilayer wood panel, the pressing force should be proportionate be applied slowly in one clamping process, as opposed to a rapid blow. Depending on the properties of the materials used in the multilayer wood panel, it may be necessary or desirable for the panels to press for five or ten seconds, gradually increasing the pressure to a maximum amount and then held at that maximum amount for a second or two. The pressing force is preferable steadily increased. .

The multilayer wood panel is cooperating between UJerkzeugteile or molding tools pressed. For best results it is important that the molds are shaped in a certain way. If the core is made of soft material, such as Balsa wood is made, the present invention teaches that the molding tool has a protruding surface, which is relative to the desired final level of the

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1828959

Part "of reduced thickness is inclined. Uienn for example the wooden board is horizontal and when it is desired to press in the upper edge of the wooden panel to create a to get horizontal indented area, it is necessary to that the molding tool has a working surface which is inclined upward as it extends outward toward the edge of the panel. This is; necessary as the amount the spring back at the edge of the plate is less is than within such an edge.

If the surface coating is relatively brittle Material, such as phenolic resin, is important that the. Form tools a tapered Edge part have a transition area that is tapered by an rich to form between the part of reduced thickness and the part of maximum thickness. This is important,; around breaking of the relatively brittle material; to avoid surface coatings

If the surface coatings are made of a non-brittle material such as aluminum, the inner edge of the protruding surface of the forming tool should be rounded, as a sharp one ^; Corner; would cause damage to the surface coating,

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In some cases it is desirable to indent both surfaces of the wood panel and only slightly indent the top surface, such as to a depth of 1.6 mm (1/16 inch). It is greasy to make an elongated thin mold as it takes to compress a long pallet only 1/16 inch (1.6 mm). Accordingly, the present invention teaches making the top die of a more easily manufactured thickness such as 1/4 inch and using a press stop and various bearing surface areas on the dies to achieve the desired level of indentation. By providing the upper molding tool with a larger support area than the lower molding tool, complete shaping of the lower impression is ensured in front of the upper impression. The press stop stops the press when the upper impression has reached the desired depth and before the full height of the form- ^ _; . Tool has been used to shape the upper impression.

Another feature of the present invention is that Crush limit of the multilayer wooden panel in front of the To reduce the application of the compressive force. This. Allows that

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Carry out the pressing process using a more difficult one Compressive force. This can be done, for example, by Er-Ui poor β η that areas of the plate are reached which are soft are to be pressed «Preferably, such heating takes place in the press, which also carries out the pressing process. :. . .; . ; ν

The present invention also teaches eliminating the Notch or the right-angled approach that so far between the part of reduced thickness and the rest the multilayer wooden board. In the present invention, a tapered transition portion connects the part of reduced thickness, with the rest of the wood ' plate. Preferably, the tapered transition piece takes increases in thickness as sr extends to the remainder of the plate. The tapered transition part contains no notches which result in a stress concentration would. *,

Such a tapered transition part can by using the appropriate tool parts or molds are formed in the pressing process. The tapered transition however, part can also be produced by a process which the pressing of the wooden plate does not

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includes. One such procedure includes removal part of the core, for example by machine Machining without the adjacent surface coating to be removed to form a recess bounded by a surface of the core and the surface coating. An adhesive is then applied to one such surface of the core is applied and the surface coating is pressed against it. ·

In order to achieve maximum strength with this method of the invention To achieve, ^ the core should be machined to form a tapered transition part. However, for applications, uio the associated burdens are relatively small, the core can simply be machined to form a groove which in ends in a notch. The notch naturally gives rise to stress concentrations. However, this method forms none the less an improvement over previously known methods by machining does not remove the adjacent surface coating, as do the previously known milling processes.

The invention is both in its construction and its Working procedure together with other features and advantages

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share ^r äavon best understood with reference to the following description in conjunction with the accompanying drawings. '".

Brief description of the drawings.

Figure Ί is a top view of a typical pallet that from a multilayer wooden panel of the present Invention is made;

FIG. 2 is a fragmentary sectional view taken along FIG Line 2-2 of Figure 1 and illustrates one embodiment the KarHenkonstruktion the multilayer Wooden board;

FIG. 3 is a sectional view similar to FIG a second embodiment of the edge construction the multilayer wood panel represents ;.

Figure 4 is an incomplete sectional view: the ver. vividly, iuie zmei the multilayer wood panels can be connected to one another at the end; - - ν

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Figure 5 is a longitudinal sectional view showing the tools for pressing a multi-layer wooden board with a relatively pliable surface coating gen and a soft core;

Figure 6 (a) and (b) are views similar to Figure 5, which the tools advanced to press the wood panel or withdrawn to spring back to allow to represent;

Figure 7 is a. View similar to Figure 5, the Effect of spring back illustrated, uienn Tools are used as shown in Figure 6 (b) are shown;

Figure 8 is a fragmentary sectional view through one second set of tools that will be used if it is desired to provide a portion of reduced thickness with a tapered outer surface »

Figure 9 is a fragmentary sectional view of a typical multilayer wood panel with relatively brittle surface coatings and a

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relatively hard core before pressing the same; ''; ■; .-:. "· ■" ■

Figure 10 is a partial cutaway view showing the Forming tools for pressing the plate of 'Fig. 9 represents.

Figure 11 is a fragmentary sectional view showing a second set of forming tools for indentation shows both surfaces of the wood panel of Fig. 9 at different depths;

Figure 12 is a fragmentary sectional view showing a ■■■ - ■ '. Edge part showed that is attached to a wooden plate, the two surfaces of which are indented to different depths; ■

Figure 13 is a fragmentary sectional view showing a shows another embodiment of the connection part;

Figure 14 is a fragmentary sectional view showing a Connecting part represents To adjoin adjacent wooden panels under a UJinkal relative to each other to fix; -

Figure 15 is a fragmentary sectional view through a multilayer wood panel, which is a first stage of another. process of reducing the thickness an edge portion of the plate illustrated;

Figure 16 is a fragmentary sectional view illustrating the final stage in the other process.

Description of the specific embodiment.

In Fig. 1 of the drawings, reference numeral 11 denotes a cargo pallet made according to the teachings of this invention. In general, the pallet contains 11 a wide, generally rectangular central portion 13 with an edge part 15 which runs along the circumference or edge area of the middle part is attached to it. The middle area 13 is preferably of a multilayer construction and contains one or more multilayer wood panels 16. The edge part 15 is preferably a metal part, which is provided to reinforce the pallet 11 at the periphery and, in the case of a cargo pallet, the fastenings 16b for attaching the cargo net or a another container arrangement for those from the cargo pallet

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provided load. Seat pallets on which Passenger seats attached öind have a plan similar to the pallet 11, with the exception that the Brackets 16b on slip pallets cannot be used.

The main reason that pallets must be firmly built is that _: They are subjected to very rough handling. The equipment for handling the pallets is not rarely defective and has a significant effect on the pallet. In addition, dynamic loads are exerted on the edge of the pallet via the edge portion 15. These dynamic loads are exerted by the cargo being picked up by the pallet and acting through the various straps and nets which hold the cargo and which are on the edge portion 15 are attached *

Figure 2 illustrates a typical edge construction for a seat pallet. In Fig. 2, the tiolzplatte contains a soft core 17, which is preferably made of grained face Balsa wood is made and has generally opposite and parallel surfaces 19 and 21. the multilayer wood panel 16 also includes surface coatings fr 23 and 25 made of pliable material, such as

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wise an aluminum sheet which is bonded to the surfaces 19 and 21 by gluing. The multilayer: - ^: · Wooden board 16 Rann of different lengths and widths ·. and preferably the surface coatings 23 and: 25 extend with surfaces 19 and 21, respectively.

The multilayer wooden board 16 u / eist a circumferential or edge portion 27 of reduced thickness and increased density. The edge part 27 includes a central part 29, the multilayer wood panel 16, and is connected to it by a tapered transition part -31. the Thickness of the edge part 27 is determined by pressing in both Sides or faces of the multilayer wood panel reduced by an equal amount, as illustrated in FIG.

The edge portion 15 is generally U-shaped in cross-section and has a pair of legs 33 and 35, which are connected to one another by a web 37. That Edge part 15 is suitably attached to the edge part 2.7 by an adhesive or by a rivet, the Legs 33 and 35 on the surface coatings 23 and 25 and the web 37 on the edge 39 of the multilayer Against wooden plate 16. With the edge part arranged in this way

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The outer surfaces of the legs 33 and 35 are essentially flush with the outer surfaces of the surface area. Layers 23 and 25 to allow the pallet to be free to be rolled along a suitable transport path, without affecting the edge part 15Ϊand by one to present a smooth upper pallet surface. The rejuvenated End faces 41 are the same as the different thicknesses Transition part 31 off.

The edge part 27, which originally had the thickness of the middle part 29, is made in a simple beam - attempt to withstand a force which is roughly equivalent to the force exerted by the central part 29 without Damage can be recorded. Expressed differently, a greater stress is required to the edge part 27 structurally damaging than they were for serving the midsection 29 is necessary. The tapered transition part / 31 also prevents excessive stress concentration at the connection of the: edge part 27 with the middle part

Various materials can be used for the core 17 will. Balsa is popular because of its high strength-to-weight ratio a good core material i'UJsnn balsa veru / ends should the grain of the wood in general

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extend at right angles to the surface coating 23 and 25, to achieve the maximum compressive strength of the balsa wood.

Figure 3 illustrates a multilayer wood panel 16a and an edge portion 15a of the type typically used used for the manufacture of freight pallets. The construction of FIG. 3 is the construction of FIG. 2 quite similar and accordingly corresponding parts in Fig. 3 are denoted by corresponding reference numerals, to which the index "a" is appended. The multilayer Wood panel 16a contains a core 17a of grained balsa wood to which surface coatings 23a and 25a are glued are. The multilayer wood panel 16a has. a tapered over ^ angular part 31a, the part of reduced thickness 27a connects to a central part 29a. The edge portion 27a of reduced thickness differs from the edge portion 27 in that only its lower surface is indented, whereas the upper surface is substantially coplanar with the upper surface of the central part in 29 is. Thus, the tapered transition part 31a is tapered only along its lower surface.

The edge portion 15a has a pair of legs 33a and 35a

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which are connected to one another by a web 37a. The web 37a is thicker and stronger than the web 37 and the Leg 33a and 35b are longer than legs 33 and Furthermore, the leg 33a is above the outer surface of the Surface coating 23a of the central part 29 before, during the leg 35a is flush with the outer surface of the coating 25a of the middle part 29a. The edge part 15a mostly a tapered end face 41a. The edge part 15a is along the edge part 27a by a number of rivets 43 (only one is shown in Fig. 3) attached, i

For various superstructures, e.g. pallets, it may be necessary or * desirable to have a pair of multilayered To attach wooden panels to each other at the front, This can be done through a connection tax 45 of in general H-shaped or double-T-shaped; Cross-section achieved as shown in FIG. The advertising part 45 connects two multi-layer wooden panels 47 and 49 with one another on the front side «The multi-layer wooden panels 47 and 49 are identical to the wooden plate 16, but can Wooden panels which have a different shape are used. That Connection part 45 preferably extends continuously along the opposite edges of the wooden panels 45 and 47 and encloses their edge parts of reduced

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Thick solid. In the embodiment illustrated in FIG the outer surface of the connecting part is flush with the outer surfaces of the free parts of the plates 47 and 49 to provide smooth, substantially continuous top and bottom surfaces. The edge parts 15 and 15a and the connector 45 and various others Similar parts are generally referred to herein as accessories designated. . ...-.-

In general, when building the pallet 11 are one or several "multilayer wood panels with edge parts of diminished Thickness provided. If more than one wooden board is used, several of these wooden boards are used together connected, as shown in Fig. 4, for example. Then the edge pieces are attached and various pallet accessories added.

Figure 5 illustrates, like a multilayer wood panel 51 with a core 53 of relatively light Material, such as grainy balsa wood, and surface coatings 55 and 57 are pliable materials, such as aluminum, can be pressed. An edge part 59 is in a press between a upper UJerkzeugteil or “forming tool 61 and a lower

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Ulerkzeugteil or molding tool 63 are pressed together. That The molding tool 61 has a flat working surface 65 and the mold 63 includes: a protrusion 67 with a generally flat work surface 69, which is relatively / 2Ur the horizontal is inclined downwards if it towards the outside towards the edge 71 of the wooden plate 51 extends. Thus, the work surface 69 is not parallel the work surface 65 but is away from the work surface 65 inclined, they open outwards towards the edge 71 2U extends. Ί ■ ..: i

An inner one. Corner 73 of the lower FormuJBrk2augeq 63 is formed with a small radius. Ein- seharfkantiga Corner u would have a tendency to cut the aluminum surfaces 55 to cut or break. The FormuierkzeugB 61 and 63 BrstTBckBTi extend lengthways in the longitudinal direction of the edge syllable 59 QbBr is the length of the edge part B that should be pressed. A press stop 75 is provided to the Abuiärtshub the upper Formuierkzeüges 61 limit.

By moving the obörön mold in the Fig ^ n · dargesteiltB position, the edge portion 59 of the multi-layer wooden plate v47 _r as shown / gepreßt- to

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an indented area 77 along the bottom of the Wooden plate. 51 to form. With the forming tools of the in In the position shown in FIG. 6a, the indented surface 77 is inclined to coincide with the working surface 69.

When the upper mold 61 is withdrawn, the edge portion 59 springs back to the extent shown in FIGS. 6b and 7 to assume the position shown, in which the indented surface 77 is substantially parallel to the upper Area of the multilayer wood panel is. UJenn the core 53 is made of a soft material, such as balsa wood, creates the application of the molding tools 61 and 63 have a tapered transition portion 79 which progressively increases in thickness as it moves away from the edge71 extends to a lateral extension of the edge part of the reduced thickness.

More specifically, the process illustrated in Figures 5 through 7 will be experienced carried out by slowly advancing the forming tool 61 to the compressive force exerted on the edge portion 59 gradually increase. As mentioned above, the Compressive force exceed the crush limit of the wooden panel 51 when the core is softer than the surface area

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Stratifications, the entire reduction in thickness occurs in the core. '

As a result of the springing back, it is necessary to remove the wooden plate 51 initially squeezing more than desired. if also a soft core is used, such as made of balsa wood, it is necessary to remove the inner areas * of the Rsndteil.es 59 to compress further than the areas of the edge part next to the edge 71, if desired, making the indented surface 77 generally parallel to the top surface of the wood panel 51.

For example, the wooden board 51 contains a balsa wood core υοη 12.7 mm (i / 2 inch) thickness with surface coatings Made of 7075-T6 aluminum, 1.6 mm (0.063 inch) thick. The lower Formuierkzeug 63 usually a maximum height of 4.57 mm (0.1B inch) and tapers to a mini. male height of 3.8 mm (θ, 15 inch) and mostly on the inner Corner 73 has a radius of 1j5 mm (θ.06 inches). the Width of the mold is 50.8 mm; (2 inch). Consequently the edge portion 59 becomes along a 50.8 mm (2 inch) wide Strips initially from an original thickness of about 15.9 mm (0.626 inches) to about 11.8 mm (0.466 inches), pressed up to 12.6 mm (0.496 inch). When the compressive force of

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the edge portion 59 is removed, causes the spring back of wood panel 51 increased in thickness from about 12.7 mm (0.5 inches) to 13.2. mm (0.52 inch) and also causes the indented surface 77 to become generally parallel to the top surface of the wood panel 51-. The angle of inclination of the tapered transition part 79 is 7 to the horizontal. . .

It will be understood that the indented surface 77 is on either the upper or lower surface of the wood panel 51 may be formed and that the core 53 could be pressed before the surface coatings 55 and 57 thereon to be glued. Using a pair of forming tools 63, both the upper and the lower surface of the wooden plate 51 can be pressed in to one of the Manufacture wooden panels 16 (Fig. 2).

Figure 8 illustrates a multilayer wood panel with a grained balsa wood coreB3, in which a Edge portion 85 of the wooden board 81 along its upper surface has been indented to form a tapered indented surface 87. The edge portion 85 is slowly 'between the molds 89; and 9.1 pressed, which have generally flat parallel working surfaces 93 and 95, respectively.

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The embodiment shown in Fig. 8 is identical with the embodiment shown in Fig. 5 to 7, except that mold parts with parallel work surfaces 93 and 95 are used and the indentation along the top surface of the multilayer wood panel 81 is formed. Although the work surfaces 93 and 95 are effective are to press the touched surface evenly, the inner area springs back further to thereby the Create inclined indented surface 87 · As with the previous embodiment, a tapered transition portion 97 formed. It is obvious that through change the angular relationship between the work surfaces 93 and 95, the indented surface 87 is caused to assume many different angular positions.

The embodiments shown in Figs use a multilayer wooden board 101 with surfaces— coatings 103 and 105 of a relatively spöden Material, such as phenolic resin, attached to a relatively hard core 107 is glued. The core 107 is made of plywood, for example.

Figure 10 illustrates the preferred tool for Depressing a surface of the multilayer wood board 101.

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Such a tool includes a top molding or tool 109 with a generally flat working surface 111, a base 113, the upper surface of which is in the is generally parallel to the work surface 111 and a lower mold 115 resting on base 113. The lower mold protrudes from the upper surface of the Base part 113 before and has a planar work surface portion 117 which is generally parallel to the work surface 111 and an inclined work surface portion 119 extending at the inner edge thereof. The work surface parts 117 and 119 are through a Radius 121 connected and the inner edge of the surface part 119 is by an inner edge 123 at a distance to the upper surface of the base 113 is arranged. The work surface 117 has an outer edge 125 a distance from the upper surface of the base part 113. A press stop 126 is provided.

The multilayer wood board 101 is placed in the press with an edge portion 127 with the work surfaces 111, 117 and 119 comes into engagement. The upper mold 109 is toward the lower mold moved to slowly squeeze and close the edge portion 127 press. The formed by the molds 109 and 115

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brought force is gradually increased until it reaches the crush limit the wooden board 101 and until the work- surface part 117 the lower surface coating 105 in has pushed inward a JYIa0 that is equal to the height of the Die 115. · This Quetsoh process takes 5 to 10 seconds. Then the upper Forming tool 109 pulled away to the wood panel 101 allow spring back and increase the thickness of the edge tile 127 to a thickness that is slightly smaller, than its original thickness, as shown in Fig. 10, only the lower surface 105 is depressed to to form a depressed surface portion 129. The inclined Work surface part 119 forms a tapered transition part 131. U / enn instead of the work surface part 119 a radius, such as the radius 73, or a sharp edge would be used, that would be proportionate brittle surface coating 105 during the pressing process break. The radius 73 can be used if the surface coatings are relatively pliable, such as when using aluminum surface coatings.

For example, a multilayer wooden board .101 a plywood core of 12.7 mm (.1 / 2 inch) thick,

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and each of the surface coatings 103 and 105 is off a 1.6 mm (1/16 inch) phenolic resin. Thickness manufactured The upper work surface part 119 has a distance of 4.7 mm (3/16 inch) to the top surface of the base and a width of 57.15 mm (2 1/4 inches). The edge 123 is usually a distance of 1.016 mm (0.040 inch) to the upper surface of the base 113. Thus rejuvenated the work surface portion 119 moves from a maximum height from 4.7 mm (-3/16 inch) to a minimum height of 1.016 mm (0.040 inch) and usually a width of 19.05 mm (3/4) inch. The molds 109 and 115 are operated to initially move the edge portion 127 to a maximum depth of 4.7 mm (3 / i6) inch) to be pressed, d. H., the full height of the lower die 115. Under these circumstances it has been found that the spring back is approximately 1.6 mm (T / 16 inch) so that the indented surface portion 129 is about 3.2 mm (I / 8 inch) is pressed in «The resulting pressed wood panel can be used, for example, as shown in Fig. 3 is shown.

The present invention also provides for the multilayer wood panel 101 to be heated before the compressive force is applied. The wooden board 101 is preferred

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heated when in the press. This can be achieved by attaching steam and / or hot water ducts or electrical heating coils 132 (FIG. 1Q;) through various parts of the press, such as the tool 109, which transfers the heat to the wooden board 101. It has been found that by using "water or steam to heat the parts of the press to a temperature of about 100 ° C " (215 ^° F) and by keeping the heated part of the press in contact with the wood panel 101 for about seven minutes the required pressing force is reduced by about 50 ^: The heating is mainly used with plates that require a pressing of more than 3.2 mm (1/8 inch) and / or brittle surface coatings of more than 1.6 mm (1/16 inch) thickness aufujais ^ en. ;;?

FIG. 11 illustrates that both surfaces 103 and 105 of wooden panel 101 can be pressed in. Flg. 11 illustrates a base 113a and a lower molding tool 115a. The lower die 115a is identical with the designated illustrated in FIG. Lower mold 10 115 and corresponding T _e ile of the mold 115a by corresponding reference numerals with the subscript "a" *

Figure 11 also shows an upper mold 115b which for movement toward and away from the wood panel 101. The upper die 115b is similar to that Mold 115 designed and corresponding surfaces of the Upper mold 115b are identified by corresponding reference numerals denoted by the index "b".

The mold 115b and 115a differ in this from each other that the former has no radius that the work surface parts 117b and 119b connects to one another and the dimensions of the two molds are different are. The surfaces T17a and 117b are thus parallel to one another, the surface 117b having a greater width, as shown in FIG. 11. In the same way, the outer edge I25b is of a lower height than the corresponding one outer edge 125a and surface 119b has a smaller angle with respect to the horizontal than the corresponding one Area 119a.

The mold i15b is with a larger area in Contact, with the wood board 101, as the molding tool 115a. Thus acts on the lower side of the wooden panel 1G1 has a greater force along surfaces 117a and 119a per unit area than along areas 117b and 119b

35

of the ¹ upper die 115b, this ensures that the indentation along the lower surface 105 will be completely formed before the upper indentation is formed. This allows the use of a mold 115b which is thicker significantly than the depth of the narrow impression, which is formed by _e In this case, keeps the press stop 134, the downward movement of the tool 115b to to excessive pressing of the upper face to prevent the wooden plate 101 . Although the impression along the surface coating 103 in FIG. If the depth is less than the impression formed along the surface coating 105, it will be understood that these impressions can be of the same depth or the upper impression can be of greater depth than the lower impression, if so desired.

FIG. 12 illustrates how the multilayer wood board 101, after it has been pressed as shown in FIG. 11, can be used in conjunction with an edge member 135. The thus-formed multi-layer wooden plate 101 has a pressed edge portion 137 and a tapered transition portion _139} tapers along both faces outwardly when he is to the uncompressed region of the wooden plate jnehrschichtigen

- 36 -. ; 008817/1004

extends. The edge portion 135 has an upper leg 141, which over the surface coating 103 on the Unpressed part of the wooden plate protrudes and a lower Leg 143, which is essentially flush with the adjacent area of the surface coating 105,

Figure 13 shows a connector 145 of H- or double-T-shape Cross section that is used to make two multilayer wood panels 147 and 149, which, as in Fig. 10 shown, are constructed to connect with each other. The lower surface 151 of the connecting part 145 is flush with the lower surface 153 of the free part of the plates 147 and 149. The connector 145 is used to connect the adjacent wood panels 147 and 149 together to form part of a pallet or for use in other constructions.

Figure 14 illustrates a connector 155 with two socket parts 157 and 159, which are under a right Angles are connected to each other. Of course it can Size of the angle between the socket parts 157 and 159, if desired, can be changed · The frame parts 157 and 159 take edge parts 161 and 163, respectively, of a pair of multilayer wooden panels 165 and 167 on, each

- 37 -

009017/1084

1B2S959

the wooden panels 165th and 167 is equal to both Surfaces indented along their edge parts so that the adjoining surfaces between the connecting part 155 and the wooden panels 165 and 167 are flush as shown.

FIGS. 15 and 16 illustrate one embodiment of the present invention in which the multilayer wood panel is not pressed. Fig * 15 illustrates a multilayer wood panel 169 with a core 171 and surface coatings 173 and 175, which are attached to the Core are glued and an outer edge 177. A Edge part of the core 171, which is directly next to the surfaces— coating · ■ 173 lies, is machined morden, around this edge part to; remove without the surface coating 173 to remove and around, an elongated. To form opening or channel 179 in wooden panel 16Ö. The groove 1:79 is formed by a surface 181 of the core 171 and bounded by the surface coating 173. The core 171 and is machined to provide a fi in general right / including notch 183 or a sloping surface 185, then an adhesive is applied to the surface 181, and, if desired, along the notch 183 or the inclined surface 185 is applied. The wooden plate 169

- ^: - ^{3B w:} "■;. ■ - ■ ■■■ '. -: V ■■ - :. 0 09Ö17 / 1004

is then brought between the Ulerkzeugteile 187 and 189 and these tools will become more sufficient with Force pressed towards each other to cause a portion 191 of the surface coating 173 to come into contact with the To lay surface 181 and attached to it by the adhesive to become. The Ulerkzeugteil 187 has an irregular shaped work surface 193 to allow the formation of an inclined portion 195 of the portion 191 of the surface area. layer 173 to allow. This prevents an essential Stretching or thinning of the surface coating, how it would otherwise arise if the surface coating tion would be pressed into the notch 183. In that case, that the notch 183 is used in place of the inclined surface 185, the space under the inclined part 195, if desired, can be filled with glue

Although the embodiment described above serves to To make the wooden plate 169 weaker, the surfaces surface coatings 173 and 175 not removed and therefore the surface coatings reinforce the edge portion of the plate 169. Since the surface coatings 173 and 175 are not removed some accessories, as shown in Fig. 2 to 4 are shown, are attached above, and the surface coatings overlap and therefore tend

- 39 -

οοββη / ιαβ-4

- 39- '.. ■ - ■ ■■' .-

to this, peeling of the coatings and moisture absorption by the core 171 'to' prevent.

If desired, the core 171 can be machined, before surface coatings 173 and 175 adhered to it will. The above-described method is particularly advantageous where weakening of the edge part of the multilayer wood panel is allowed.

Although examples of embodiments of the invention shown and described, many can Changes, modifications and substitutions of Anyone skilled in the art can do so without necessarily departing from the spirit and scope of this invention to deviate.

Claim? '

- 40 -

0098 17/108

Claims (7)

Pa t θ η t a η s ρ r ü c h θ (1 ", JWood panel construction, characterized by a contiguous core (17) with first and second, generally opposed surfaces (19, 21), a first part (29) of predetermined thickness and density and a second pressed part (27), the has a thickness less than the predetermined thickness and a density greater than the predetermined density, the first and second parts of the core being made of the same material, a first and a second surface coating (23, 25) which are applied to the first and second surface coatings, respectively. the second, generally opposed surface (19, 21) of the core (17) and extending over both portions of the core, the first and second surface coatings generally contouring the first and second, respectively, generally opposite surface coincides _r whereby the core and the surface coatings form a multilayer wood panel (16), which is a first part of a given thickness and D icht and a second part with a smaller thickness than the given thickness and a 'greater density - 41 - 0 0 9 8 17/1084 162895B than the given density "and an accessory (15, 45) attached to the multilayer wooden board and extends along its second part * 2. Wooden panel construction according to claim 1, d a d υ r c h g e k e η η ζ ei c h η e t, dal3 the multilayer wood board (l6) contains a pallet (11) and the second Τθί1, (27) an edge part of the multilayer Wood panel is. . ; 3. wooden panel construction according to claim 2, d ä - by ge k en η I show η et that the _: accessory part contains an elongated edge part (15) which is attached to the multilayer wood panel (To) along its edge part (27), the edge part being generally U-shaped Has cross-section and encloses the edge part of the multilayer wooden board and, part of each "of the surface coatings in the Kantenta.1 (15) is added to increase the strength of the pallet. 4. Holzpiattenkonstrüktion according to claim 3, since d u rchgeke η η I ze η et that the generally misshapen part of the edge part * a 009017/1084 has outer surface that is substantially flush with the outer surface of one of the surface coatings. 5. wooden panel structure according to claim 1, d a d u r ch characterized in that the core (17) is made of plywood is hergsäbellt and the surface coatings (23, 25) are made of a phenolic resin. 6. wooden panel structure according to claim 1, d a d u r ch characterized in that the core (17) consists of grained balsa wood is made and the surfaces— coatings (23, 25) are made from lYletall. 7. wooden panel structure according to claim 2, d a d u r ch characterized in that a tapered transition part (31) the first and the edge part of the multilayer Join wood panel together with the tapered transition part increasing in thickness as it moves extends in the direction of the first part. 00901771034 te Lee r-S-e ι te