WO1998008743A1

WO1998008743A1 - An assembly of nailable material, such as a loading pallet

Info

Publication number: WO1998008743A1
Application number: PCT/NL1997/000483
Authority: WO
Inventors: Klaas Willem De Groot
Original assignee: Klaas Willem De Groot
Priority date: 1996-08-26
Filing date: 1997-08-26
Publication date: 1998-03-05
Also published as: US6494149B1; NL1003882C1; AU4034197A; EP1007421A1

Abstract

A construction, such as a pallet, provided inter alia with plate-like components of nailable material, for instance of wood and/or wood fibres, plastic and the like which are pressed together with glue under pressure and/or with addition of heat, wherein at least two plate-like elements, each of random thickness, are joined together on the mutually facing surfaces using one or more whether or not spatial nail elements in order to increase the carrying capacity of the pallet construction. If desired the space between the deck plates can be filled with a material of a low specific gravity, like foam.

Description

AN ASSEMBLY OF NAILABLE MATERIAL, SUCH AS A LOADING PALLET

The invention relates to a construction, such as a pallet, provided inter alia with plate-like components of nailable material, for instance of wood and/or wood fibres, plastic and the like which are pressed together with glue under pressure and/or with addition of heat.

Due to its composition and production method the plate material has a sufficiently high modulus of elasticity and sufficient capacity to withstand shear, pressure and tensile stresses and distribute them while being loaded for instance perpendicularly of the surface of the plate-like element.

The invention has for its object to further improve the carrying capacity of such a construction and provides to this end a construction which is distinguished in that at least two plate-like elements, each of random thickness, are joined together on the mutually facing surfaces using one or more nail elements.

The nail element is per se known from the Netherlands patent application number 9101725 with the title "Method and device for manufacturing a nail element".

An advantage of using a nail element on the joint face of two nailable components both of equal thickness is that it is possible to achieve that the thus joined components can withstand a load perpendicularly of the surface which is four times the load which a component used singly can withstand.

In order to enable a still better absorption of pressure load, the plate-like body of a nail element can have a minimum of one reinforcing rib rolled therein. The form of the rib can be a milled recess for a good fit in the nailable component .

In the case of nailable elements joined together from a minimum of three parts with nail elements, a nail element can also be co-pressed in the tensile zone on a joint face. The application is also possible of fixing a nail element both in the assembly of at least three nailable elements on the joint face in the middle of the constituent parts and in the tensile zone of the assembly. With- standing of compression and tensile stress can hereby be optimized.

In order to achieve a good resistance against shearing of the assembly it is important that the elongate members of the nail element are determined and positioned in the correct manner. It is thus possible to embody the nail element as a spatial body which is arranged between the upper and lower plate of the construction. The connection takes place once again with nail-like fixing means which can be driven into the upper and lower plate. The spatial body can be formed from plate material which has been formed into a tube but can preferably be embodied as a framework which can be made particularly from a wire mat. This wire mat can be folded along predetermined lines to form a spatial construction. The nail -like fixing means can be fixed to the spatial body in random manner but in the case of a wire mat the invention further proposes to cut through predetermined wires of the flat mat, which cut parts protrude outside of the spatial body after folding of the mat and thus form nails. For some applications it can be advantageous to fill the assembly with a foam material in the space between the upper and lower plate which embeds the spatial body.

In order to optimize resistance against the elongate members being pulled out of the nailable material, it is important that the ends of these members are given a chamfering such that during and at a correct speed of pressing in they preferably assume a so-called open-tulip position in the nailable material.

As a result of the two described nailable components when joined together being able to withstand a minimum of four times a pressure load, it is also possible to reduce the thickness dimension of the nailable plate material to a thickness sufficient to withstand a load suitable for a single nailable element. On the other hand, due to the ability to withstand a higher load, the option is present of allowing a heavier load on an identical surface.

A practical use of the thus obtained assembly is for instance the application thereof as the deck of a loading platform (pallet) . In current practice standard pallets are constructed from usually wooden parts of small width wherein the so-called top deck is first fixed to a so- called intermediate deck, whereafter this thus assembled pallet deck is fixed with nails to wooden or plastic spacers. The number of spacers amounts to nine in order to make the pallet construction sufficiently rigid and stable. These spacers are placed such that each side of the rectangular form contains three, with one placed in the centre of the pallet construction. At a prescribed length the spacers leave space allowing access to for instance forks of (internal) transport material such as fork-lift trucks from the ground or a substructure of the pallet. This known pallet construction with nine spacers allows of a fork access on each rectangular side and is called a four-way pallet. Pallet constructions are also known which have both a top deck and a bottom deck, so- called double-decker pallets. The spacers are then arranged between the intermediate decks .

The pallet construction according to the invention allows the nail element to join together on the joint face two nailable components of for instance rectangularly shaped plate material along the diagonals of the rectangle. The nail elements, which may or may not be provided with reinforcing ribs, allow the utilization of a metal bush, which is pre-fixed to the nail element and has for instance an internal screw thread, on these elements via a recess on the underside of the nailable material in order to enable for instance a cylindrically formed spacer to be screwed on. Since the joined together nailable components have such a great capacity to withstand pressure load, it is possible to fix only five spacers to the pallet deck, i.e. on the four corners and one in the centre of the pallet construction. This gives fork access to (internal) transport material on eight sides of the pallet, i.e on the four rectangle sides in addition to the diagonal directions. It is then possible to speak of an eight-way pallet. The advantage of being able to utilize an eight- way access is present in the possibility of achieving time-saving because for instance a pallet truck or fork- lift truck does not have to take an angle of 90° in all cases .

Should still more rigidity be required of the pallet construction, a nail element can then also be co-pressed functionally on the joint face on each rectangle side. The pallet construction according to the invention can likewise be provided with a bottom deck. The spacers can be screwed in simple manner to the bushes by giving these latter opposing threads. Because the spacers are screwed onto a bush fixed to the nail element and provided with a screw thread it is also possible to couple these to for instance a rod of vibration-damping or vibration-absorbing material, consisting for instance of rubber and/or plastic. Instead of to a rubber/plastic rod it is also possible to couple to for instance a double-action hydraulic cylinder and, although this is not immediately obvious, to a construction with a gas spring. Since coupling to the bottom deck of a pallet is possible in a manner identical to coupling to the top deck of a pallet, the pallet can also be employed upside down while retaining vibration-damping and vibration-absorbing properties. The advantage of a thus constructed pallet is the possibility of for instance being able to adjust the rupture value of carton constructions which permit a lighter gram weight per unit. Since the construction of the spacer likewise has a good capacity to withstand shocks, also in horizontal direction, which may occur during use in a transport path, it will be possible to reduce the consequences of subsequent damage.

The invention will be further elucidated in the figure description hereinbelow of a number of embodiments .

In the drawing: fig. 1 shows a perspective view of a nail element wherein the plate-like body has had a reinforcing rib rolled therein, fig. 2 shows a perspective view of an embodiment of a loading platform provided with nail elements extending diagonally on the joint face between two nailable platelike elements which are joined together under pressure to form a loading platform deck, fig. 3 shows a cross-section of a nail element pressed between nailable material with attached elongate members which display a so-called open-tulip position, fig. 4 shows a perspective view of a corner reinforcement in a plate-like body of a nail element bent through 90°, fig. 5 is a perspective view of the upper part of a bottom deck of a loading platform (pallet) with a metal bush of cylindrical form fixed by spot welding to the nail element and provided with an internal screw thread for screwing in the spacer, fig. 6 is a perspective view of a metal, cylindri- cally formed spacer with external screw thread on both sides such that one side fits into the bush of fig. 5 and the other side can be utilized for screwing on a flange of larger diameter to enable increased stability of the pallet, fig. 7 shows a section through a spacer which has between metal plates with threaded connection a rod of rubber vulcanized thereon. Said metal plates are fixed to coupling pieces provided with screw thread which are suitable for screwing on the bush of fig. 5, fig. 8 is a perspective view of a loading platform (pallet) provided with an upper and lower plate which are held spaced apart by a spatial body provided with nail- like fixing means. fig. 9 shows a wire mat for manufacturing a spatial body of fig. 8, fig. 10 shows a detail of the forming of the nail- like fixing means in a wire mat as according to fig. 9. Designated with the numeral 1 in the figures is the nail element which consists of a plate-like body with elongate members 2 fixed thereto, this as described in the earlier Netherlands patent application 9101725. Such a plate- like body is arranged between two plates of nailable material, as shown in fig. 2. These plates 4 are placed under pressure on nail-like elements 2 so that a firm attachment is effected between the lower and upper plate .

In order to increase the bending stiffness the plate-like body 1 in fig. 1 is embodied with a reinforc- ing rib 3. When the upper and lower plate are of particular materials this reinforcing rib 3 can be pressed therein but the rib can also serve as spacer between both plates, whereafter this space may or may not be filled with a foam material . Fig. 2 shows in particular that the nail-like element 1 runs at a diagonal to the rectangular upper and lower plate 4. A second nail-like element is arranged along the other diagonal .

By not giving the nail -like members 2 a tip but cutting them off in a straight plane which runs obliquely of the lengthwise axis of the nail -like member, a force can be exerted on the nail -like member 2 during pressing such that it will begin to bend, see fig. 3, wherein a so-called open-tulip position is realized This increases the pull-apart value of plates 4.

Fig. 4 shows a detail of a nail -like element 1 which is bent through an angle whereby the bent portion can protrude outside plates 4 and can serve for fixing of other elements, for instance spacers, if the construction is used for a loading platform, for instance pallet. The corner reinforcement takes place with a rib 3' which can be obtained by cold deformation.

Fig. 5 shows an alternative for arranging elements for the mounting of spacing pieces. For this purpose the corner of upper plate 4 is removed whereby the corner of the plate 1 of the nail element is exposed. If this plate is of weldable material a bush 5 can be arranged which is provided with a flange 6 which can be attached to plate 1 by means of spot welds. The bush can be provided with an inner thread 7, using which spacers provided with an outer screw thread can be screwed therein. These spacers can be of random type .

Fig. 6 shows a possible embodiment wherein the spacer is provided on both ends with an outer screw thread 8 which co-acts with inner screw thread 7 of bush 5. By giving the screw thread 8 an opposing pitch at the top and bottom the spacer can for instance mutually connect two pallet decks by screwing them simultaneously into bushes 5, wherein a so-called double pallet is created. The spaces between upper and lower decks serve to receive the forks of a fork-lift truck, this being assumed generally known.

Fig . 7 shows a damping spacer corresponding with that of fig. 6, although of a shock-absorbing material, for instance rubber. The rubber body 12 is provided on either end with a vulcanized flange 11 which is provided centrally with a recessed threaded bush 13. This recessed threaded bush 13 co-acts with a threaded stub 14 which is fixed to a flange 6 which can be attached in the manner shown in fig. 5 to nail-like element 1. With such shock- absorbing spacers 12 a pallet can be manufactured which can carry shock sensitive freight.

Fig. 8 shows an embodiment wherein the upper and lower decks 4 and 4' are held apart by a nail element embodied as a spatial body. The starting point is a wire mat as according to fig. 9 which is bent in zigzag form round the lines A, B and C. This results in a crenellated construction which can be mounted in suitable manner on the nailable lower and upper decks 4 and 4' . A possible embodiment is to cut through the wires of mat 9 at suitable positions at D, whereby after folding round the lines the released portions will point upward, as shown in fig. 10. These portions can function as fixing means by pressing them in the manner shown in fig. 3 into the upper and lower plate 4 and 4' .

Fig. 8 also shows that the space between the lines A and B can be filled by means of a foam material . The spaces left clear can serve to receive the forks of a fork-lift truck. If desired, the whole space can be filled with said foam material of random nature, whereby an assembly results which can serve per se as an upper deck for a pallet. This must then be provided with spacer pieces as shown in fig. 6 to create space for the forks of a fork- lift truck.

The invention is not limited to the above described embodiments. The nail -like element 1 of fig. 1 may also be provided with more plates at a distance one above another. The connections between the plates are provided by the elongate elements 2. The optional upper and lower plates 4 and 4' are thereby also separated from each other at a greater distance than shown in fig. 3, whereafter the space therebetween can if desired be filled with a foam material as according to fig. 8.

Instead of foam material other reinforcing steps can also be applied, such as shores or profiles which are incorporated in the wire mat .

It will be apparent that by using appropriate mate- rials for plates 4, nail-like elements 1, spacers 9, 12 diverse assemblies, in particular loading platforms, can be manufactured which are specifically suitable for a particular type of load that has to be transported.

The spacers 9 of fig. 6 can of course also be pro- vided with castors, whereby the pallet can be transported on its own wheels. This enables use of the pallet in automated freight handling by means of per se known conveying means . The spacers can moreover also serve as coupling pieces for adjoining loading platforms, whereby the loading platforms can be arranged as a train.

Claims

1. Construction, such as a pallet, provided inter alia with plate-like components of nailable material, for instance of wood and/or wood fibres, plastic and the like which are pressed together with glue under pressure and/or with addition of heat, characterized in that at least two plate-like elements, each of random thickness, are joined together on the mutually facing surfaces using one or more nail elements .

2. Construction as claimed in claim 1, characterized in that a nail element is arranged in the tensile zone of the plate- like element to optimize the carrying capacity.

3. Construction as claimed in claim 1 or 2 , characterized in that the nail element embodied in the form of a plate has, against bending, a minimum of one reinforc- ing rib in the plate part.

4. Construction as claimed in any of the claims 1-3, characterized in that the plate part of the nail element is bent at an angle, for instance of 90°.

5. Construction as claimed in claim 1, characterized in that the nail element is embodied as a spatial body provided with nail-like fixing means for connection to said surfaces of the upper respectively lower plate-like element .

6. Construction as claimed in claim 5, characterized in that the spatial body is formed as a framework from a flat wire mat which is folded along predetermined lines.

7. Construction as claimed in claim 6, characterized in that predetermined wires of the flat mat are cut through to form nail-like fixing means after folding.

8. Construction as claimed in any of the foregoing claims 5-7, characterized in that the space formed by the framework between upper and lower plate is filled with a filler such as a foam plastic.

9. Construction as claimed in any of the foregoing claims, provided as loading platform (pallet) with at least four spacers, characterized in that a metal bush is fixed to the nail element, for instance by means of spot welding.

10. Construction as claimed in claim 9, characterized in that the metal bush is provided with an internal screw thread for fixing of the spacer.

11. Construction as claimed in claim 10, characterized in that the spacer is likewise provided on the opposite side with a screw thread to enable fixing of a flange of larger diameter.

12. Construction as claimed in claim 11, characterized in that the screwable top and bottom part of the spacer is coupled to for instance a rod of vibration- absorbing and/or vibration-damping material .