The subject of the invention is a cardboard pallet. The solution is applicable in the broadly understood transport industry, since the cardboard pallet serves as a carrier of many kinds of goods.

From common knowledge it is known that minimizing the weight of elements supporting the transport of goods is very beneficial, regardless of whether the transport is occasional or is repeated many times for the same or different type of goods.

In the transport industry, in particular for the industry that produces measures to support such transport, it is known that, apart from the light weight, all auxiliary measures, especially transport pallets are unified as to the dimensions, but above all as to the load capacity of the pallets appropriately assigned to the construction. Commonly used wooden pallets are durable and can be used for a long time as a means of supporting the transport of goods, however they are not light, and it is difficult to change their size after use because they are incompressible

Hence, there are a number of solutions that replace wood used in the construction of the pallet, replacing them with cardboard or corrugated cardboard.

These solutions include, for example, those indicated in the German patent number DE0291836B1, the German utility model with the number DE202005007642U1 or the British application GB2397568A1. Although these solutions use lightweight material structures, paperboard and cardboard to create a transport platform, these solutions do not constitute a lasting and stable construction.

From the Polish solution that obtained the patent with the number PAT. 219905, however, a much stronger and lightweight cardboard pallet is known. It contains the upper plate, side walls of the legs, slats and the lower plate, made of one pattern, and it is made by bending the same pattern into the shape of the pallet. To the upper plate on two sides, the side walls of the leg are adjacent, and the legs are adjoin by the slats, to which the slats on the opposite side adjoin the next side walls of the leg, while the side walls of the legs in both extreme parts of the pattern are adhered to the parts of the lower plate. The key to this known solution is what provides strength to the entire pallet, namely the legs, each of which is formed of two vertical side walls and a horizontal joining slat, the legs are in the form of multilayer blocks of glued cardboard while the side walls have two rectangular cutouts. For a strengthening between the upper plate and the lower plate there may be a reinforcing insert. The reinforcing insert can be in the form of three adjacent rectangles, two of which have the width of half the central rectangle. The reinforcing insert in the presented type, unfortunately, is not strong enough. The well-known palette has a durable leg construction, but the platform is less durable.

From another Polish solution with the application number P. 382171, a plate is known, especially a cardboard one, which consists of two flat surfaces, between which there are filling elements in the form of cardboard strips or paper. The filling elements are arranged perpendicular to the surface of the plate and parallel to each other, forming lines repeatedly broken whereby the distances between the lines are such that on the surface under the top of the line there are at least two vertices of the following lines, and the tops of the lines have a sharp shape or the shape of an arc.

However, this solution is not useful for the transport industry, although it seems to be a good direction for strengthening a large surface made of paper.

The object of the solution according to the invention is to find an optimal strength lightweight structure that could be a transport platform for various types of goods, and therefore also variable loads, in particular for heavy weights. The goal is best to create a lightweight structure replacing durable wooden constructions constituting transport platforms. The goal is also to create a structure which, at the time of possible mechanical strain, will be able, to a greater extent than currently known constructions, to retain its almost intact form despite the damage, thanks to only a point distortion.

The cardboard pallet according to the invention comprises an upper plate and a lower plate, legs and side walls of legs, where the side walls of legs are adjacent to the upper plate and/ or to the lower plate, and each leg is attached at least to the lower plate and is formed of vertical side walls and at least one multilayer block of glued cardboard between them, while between the upper plate and the lower plate there is at least one reinforcing insert from cardboard. The distance between the upper plate and the lower plate is at least 8mm. The reinforcing insert has glued filling elements arranged one on top of the other, perpendicular to the upper plate and lower plate, the filling elements being respectively a two layer cardboard consisting alternately of a wavy layer and a flat layer, or a three layer cardboard consisting alternately of a flat layer, a wavy layer and a flat layer, where the height of the wavy layer is larger than 5mm. The invention is characterized in that within one reinforcing insert there is a patch which has waved layers of varying height and/ or the reinforcing insert has at least two multilayer patches, wherein the flat layers of each patch are perpendicular to the lower plate and the upper plate and at the same time are non-parallel with respect to flat layers of the adjacent cardboard patch of the same reinforcing insert, where the patch has a width of 100mm or less.

Beneficially, at least one selected wavy layer in the same patch has a height different from the height of the remaining unselected wavy layers in this patch. Beneficially, the wavy layers of various patches have a different height. Beneficially, the wavy layers of the filling elements of the reinforcing insert of one patch are parallel to each other. Alternatively beneficially, the wavy layers of the filling elements of the reinforcing insert of one patch are parallel to each other, while the wavy layers of the filling elements of the reinforcing insert of the various patches are non-parallel to one another. Beneficially, between the lower plate and the upper plate there are more than one reinforcing insert, they are arranged on top of each other with an excess separating divider, beneficially paper, parallel to the lower and upper plate, i.e. vertically, partially or completely one above the other. Beneficially, between the lower plate and the upper plate there are more than one reinforcing insert, they are arranged side by side, i.e. horizontally one next to the other. Beneficially, two side walls are walls common to three legs, comprising three independent fillings of a multilayer block of glued cardboard. Beneficially, the lower slats adhere to the legs, where one lower slat connects three legs arranged in line. Beneficially, the side walls of the legs are adjacent to the sides of the upper plate. Beneficially, the lower plate and, at the same time or alternatively, the upper plate are connected by an additional protector with a reinforcing insert, preferably on the envelope of the plates. Beneficially, at least one leg, preferably the extreme one, is in contact with the protector. Beneficially, any of the plates, i.e. the upper plate, the lower plate, the divider is made of multilayer cardboard and they are multiplied. Beneficially, the upper plate, the lower plate and the side walls of the legs are made of one puncher that has parallel creasing lines. Beneficially, the height of the wavy layer can assume a value from between the two sides closed from 6mm to 50mm. Beneficially, the patches of the same reinforcement insert are connected to each other by adhesive joints or are releasably arranged relative to each other, preferably at an ALPHA angle in the range of 30° to 90°. Beneficially, the horizontal patches are connected to each other by adhesive joints or are releasably arranged relative to each other, preferably at an ALPHA angle in the range of 30° to 90°. Beneficially, the patches in one reinforcing insert are no more than four pieces. Beneficially, the reinforcing inserts are no more than four.

The palette is made on the technological line, where the basic, double-layer or three-layer, type of corrugated cardboard is made then glued together until the appropriate and planned total number of layers is obtained. This total number of layers can, however, be different for the lower plate, upper plate, divider, which may vary in thickness, and certainly bigger will be the number of total layers for the stack, out of which will then be cut or broken a block for each leg of the pallet and finally the most will be the total amount of layers in the stack, which will then be cut into thin patches. Cardboard walls are also cut out from the cardboard, which can be extended to the leg block and creased. Independently, the obtained elements are glued together during folding in the pallet construction, legs under the lower plate, which are covered with side walls, which overlap above the cardboard block filling each leg. Alternatively, the upper plate, lower plate and possibly side walls of legs or protectors can be surrounded by a dust jacket from one puncher with parallel creasing lines. Most importantly, the prepared patches are chosen in terms of width so that, while maintaining the consistency of the width, the patches can form one layer, in its function being the carrier layer of the pallet. At least two patches are composed into one reinforcing insert, whereby they are arranged so that the flat layers of the adjacent cardboard patches are set at an angle to each other, according to the rules outlined above. Ideally, this angle is a multiple of 15° angular measure. It also turned out that instead of multiplying the number of patches in one reinforcing insert, it is also possible to make a structural change by varying the heights of the wavy layers in the reinforcing insert. Both treatments achieve zone separation of the surface of the pallet, thanks to which the mechanical distortion of a certain point of the top structure of the pallet is not easily transferred to more distant from this point. On a similar basis, the detachable laying of patches constituting one reinforcing insert results in a better insulating effect between the patches and a beneficial effect as indicated above. Thanks to this insulation, any mechanical damage of one patch is not transferred to the location of another patch. An even better effect can be observed after multiplication of the number of patches located in one plane, regardless of whether in the same or in another reinforcing insert. The multiplication of the patches allows to reduce the surface of any point damage to the layer that transfers the pressure of the goods placed on the pallet. If the patches are arranged in the same plane and do not constitute the same reinforcing insert, which is not a drawback, they can be arranged so that the flat layers of the cardboard of the patch are parallel to the flat layers of another patch on the same plane, but it will not be adjacent patch. It is also acceptable to cross join the abovementioned features, which gives the best technical benefits of the pallet construction. This is what the structure according to the present invention provides, and this translates into an improvement in the strength of the pallet. The best structural effect is obtained when in addition to this construction condition two layers of reinforcing inserts will be used. Then, the principle of rotating adjacent patches will also translate into a vertical arrangement of patches, not just horizontal. The structure will then be significantly strengthened.

The solution is shown in the embodiment in the drawing, in which Fig.1 shows the cardboard pallet of the first embodiment divided into elements, Fig. 2 shows the cardboard pallet of the first embodiment folded together, Fig. 3 shows a fragment of the reinforcing insert between the upper plate and the bottom of the first embodiment as individual enlarged layers, Fig. 4 shows the cardboard pallet of the second embodiment partitioned into elements, Fig. 5 shows the cardboard pallet of the second embodiment folded together.

The cardboard pallet 1 comprises an upper plate 2 and a lower plate 3, legs 4 and side walls 5, where the side walls 5 legs 4 adhere to the upper plate 2 and the lower plate 4, and each leg 4 of the three legs 4 is attached to the lower plate 3 and is formed of two vertical side walls 5 and three multilayer blocks 6 of glued cardboard between them, while between the upper plate 2 and the lower plate 3 there is a reinforcing insert 7 made of cardboard. The reinforcement insert 7 has filler elements 8 arranged perpendicular to the upper plate 2 and the lower plate 3, the filler elements 8 being a two-layer cardboard consisting alternately of the wavy layer 9 and flat layer 10, which cardboard is adhered to one multilayer patch 11, the patch 11 is perpendicular to the lower plate 3 and the upper plate 2, where the height of each waved layer 9 is in a double-sided closed range from 6mm to 50mm, in this case 50mm inside the patch 11 and 6mm on the edge of the patch 11 and the distance between the upper plate 2 and the lower plate 3, which is filled with one reinforcing insert 7, amounts from 8mm to 100mm, i.e. in this case 8mm. Hence, it is clear that the selected wavy layers 9 in the same patch are of different heights. The filling elements 8 of the reinforcing insert 7 constituting one patch 11 are parallel to one another, in particular the flat layers 10 with respect to each other and the wavy layers 9 to each other. Two side walls 5 are walls common to three legs 4, each containing three independent fillings of a multilayer block 6 of glued cardboard. To the legs 4 are attached lower slats 4, with one lower slat 12 joining three blocks 6 of one leg 4 aligned behind each other. The side walls 5 of the legs 4 are adjacent to the sides 13 of the upper plate 2. Any of the boards, in this case both the upper plate 2 and the lower plate 3, are made of multilayer cardboard and are multiplied respectively into two glued three layer boards 2', 3' which in total gives six layers for each of the 2 and 3 plates. Upper plate 2, lower plate 3 and side walls 5 legs 4 are surrounded by dust jacket 14 from one puncher having parallel creasing lines 15.

As in the first example with the following differences.
Each leg 4 is made of one block 6 and two side walls 5, and there are nine legs 4. The filling elements 8 are a three layer cardboard consisting alternately of a flat layer 10, a wavy layer 9 and a flat layer 10. The cardboard is glued into five multilayer patches 11. The height of each wavy layer 9 is in a double sided closed range from 6mm to 50mm and is both 15mm and 35mm, and the distance between the upper plate 2 and the lower plate 3, which is filled with two reinforcing inserts 7, is from 8mm to 100mm, i.e. 100mm in this case, wherein the first reinforcing insert positioned below consists of four adhesive bonded adhesive patches 11, the first reinforcement insert 7 has a height of 25 mm, and the second reinforcement insert 7 placed above has a height of 75 mm and constitutes one patch 11 connected to the preceding releasably, reinforcing inserts 7 are separated by one layer of a divider 16 made of paper. The upper reinforcing insert 7' has wavy layers 9 with a height of 15mm, 13mm and 14mm, and the lower reinforcing insert 7' has wavy layers 9 with a height of 35mm, hence it is clear that the wavy layers 9 in different patches 11 have different heights, in this case this applies to patches 11 located in various reinforcement inserts 7', 7".
The filling elements 8 of the reinforcing insert 7 constituting one patch 11 are parallel to each other, whereas the filling elements 8 of the different patches 11 are non-parallel to each other, as they are set at an angle of 90° to those of the adjacent patches 11 arranged at the same lower level, that is, in one lower reinforcing insert 7", while in one upper reinforcing insert 7' all filling elements 8 are parallel to each other, but for it the height of wavy layers 9 is variable. As mentioned, between the lower plate 3 and the upper plate 2 there is more than one reinforcing insert 7 arranged on top of each other with one excess separating divider 16 made of paper parallel to the lower plate 3 and the upper plate 2, and also between the lower plate 3 and the upper plate 2 there are more patches 11 arranged side by side. The lower plate 3 and at the same time the upper plate 2 are connected by an additional protector 17 with a reinforcing insert 7, after the envelope 18 of the upper plate 2 and the lower plate 3, both on the upper plate side 2 and on the lower plate side 3, which was made by using a protector 17 of eight cardboard angles. Extreme legs 4, a total of eight pieces, are in contact with the protector 17 via the side wall 5. The divider 16 is made of multilayer cardboard made of paper. The protectors 17 fixed on the lower plate 3 together with the lower plate 3 come into contact with the side walls 5 of the enveloping legs 4 on the two sides of the cardboard pallet 1, which side walls 5 extend to the edges of the protectors 17 fixed on the upper plate 2. Cardboard pallet 1 with this embodiment is not provided with lower slats 3 or dust jacket 14.

As in the first example, the upper plate 2, the lower plate 3 and the side walls 5 of the legs 4 are made of one puncher having parallel creasing lines 15.