Pallet base and pallet provided with said base

The present invention relates to a palette and pallet base provided with such a base, made of plastic with metal parts, suitable for stacking and highly resistant to bending, and also allowing safe handling on a pallet rack.

BACKGROUND OF THE INVENTION [0002] Pallet bases are known in the prior art that include an inner honeycomb structure made of plastic, two metal sheets placed on each side of the plastic inner structure and two outer sheets made of plastic adhering to metal sheets. .

[0003] Patent document WO2006 / 011728 discloses an example of this type of pallet base. However, the subject matter of the patent is fraught with a number of disadvantages that limit its use, which explains their low level of large-scale deployment.

[0004] First, it has a very complex structure, with many parts, especially complex laminates, which imply costly processes and not very competitive costs.

[0005] Comprehensive laminates arise from the need to provide adjoining surfaces to realize a tight connection between the various layers.

[0006] This tight connection is necessary to ensure that the metal sheets fulfill their function of resisting tangential stresses occurring when loads are supported on the pallet. [0007] Furthermore, such a tight connection is not resistant to fatigue conditions, in particular to the relative displacement of the layers caused by expansion or use.

[0008] At the same time, plastic pallets having nested pockets and adapted to withstand a load of at least one ton when placed on a rack with support beams are not known in the prior art.

Other examples of such structures are disclosed in US 2009116925 A1, US 6651815 B1.

[0010] Patent documents US 5205221 A, GB 2089316 A, US 5566624 A and US 2009025616 A1 disclose pallets associated with the invention.

For these reasons, the inventors of the present invention consider it necessary to develop a palette base in addition to a pallet equipped with such a basis for overcoming the disadvantages of the solutions already existing in the prior art.

SUMMARY OF THE INVENTION [0012] For this purpose, a palette base according to claim 1 has been proposed. 1, which contains:

- the internal honeycomb structure made of plastic;

- two metal sheets disposed on each side of the inner plastic structure and extending over the entire inner honeycomb structure;

- two outer plastic sheets attached to the metal sheets;

wherein the ends of all connecting edges of the honeycomb cells protrude above the cells, and the metal sheets are provided with through holes for the passage of these edge ends, which ends are welded to the outer plastic sheets.

[0013] Such a structure allows a uniform surface connection between the metal sheets and the rest of the base and is adapted to withstand considerable tangential currents. In particular,

EP2767482 B1 has been convinced that such a structure is adapted to support, even on a rack, loads greater than one ton.

[0014] Furthermore, this solution simplifies structures known in the art and can be produced at a lower cost.

[0015] None of these documents have been disclosed in any of the prior art documents. Combining the described documents to obtain the claimed invention is also not evident.

[0016] Patent document US 2009116925 discloses a base which comprises an inner honeycomb structure made of plastic, two metal sheets placed on each side of the inner plastic structure and two outer sheets made of plastic and adhered to metal sheets.

[0017] However, nowhere is it suggested that the ends of the connecting edges of the honeycomb cells outperform these cells, and the metal sheets are provided with through holes for the passage of the edge ends, which ends are welded to the outer sheets of plastic.

[0018] Patent document US 6651815 B1 also discloses two metal sheets, placed on each side of the inner plastic structure and two outer frames made of plastic and adjacent to the metal sheets.

[0019] Similarly, there also are disclosed the ends of the edges connecting some cells that are rectangular and not honeycombed, which protrude above the cells, wherein the metal frames are provided with through holes for the passage of the ends of these edges.

[0020] However, the following differences exist:

- the ends are not heat-welded with external sheets made of plastic;

- a frame is used, not a sheet;

- the honeycomb structure is not disclosed, for which reason said frame was used;

[0021] More specifically, it is a combination of these features that allows a much greater load to be supported than on the prior art bases.

[0022] In particular, the tight sealing connection between the outer sheets and the inner structure is essential, and it is also essential that the entire honeycomb structure be covered with metal sheets.

[0023] In a separate reference, according to various optional features of the invention:

the inner honeycomb structure made of plastic has a lateral boundary that closes the peripheral cells, which lateral boundary extends along both sides to adapt the respective frames for the nesting and connection of the outer plastic sheets attached to the metal sheets.

the lateral boundary extends over the upper surface at a greater distance than the added thickness of the metal sheets and outer plastic sheets in such a way that it constitutes a lateral support ring for the loads that occur on the pallet.

- the base includes holes for mounting legs.

- the openings include reinforcing walls connected to the honeycomb cells.

these openings define a change in cross-section in such a way that the support surface is adapted for the legs and preferably has an elliptical contour with two circular inlets on the nearest sides of the ellipse facing the opening.

EP2767482 B1

according to a particularly advantageous variant, the base comprises nine substantially elliptical openings, four at the corners and directed towards the maximum dimension of the base, three at the central part directed towards the maximum dimension of the base, the other two oriented perpendicular to the others.

- the walls of the openings are inclined to allow the nesting stacking of a number of pallets.

- the base includes in its internal structure two reinforcing beams, centered and crossed, and tightly connected to the honeycomb structure.

- the base includes one of its short sides, two sloping frames for nesting the forks.

[0024] In a separate aspect, the invention also relates to a pallet comprising a base such as described herein and also removable legs.

[0025] Preferably, the legs comprise a metal insert in their base, leveled or superior to the leg body, and extending practically over the entire leg length.

[0026] Preferably, the legs comprise vertical ribs to support and attach the insert and support stacked to the pallet.

[0027] More preferably, the legs comprise drainage holes in the base of the legs.

[0028] Preferably, the pallet comprises fixing means by attaching the legs to the base.

[0029] Finally, in the pallet of the invention, the leg pads have a section comprising a rounded portion in their support zone and a rectilinear portion for stiffness in the longitudinal direction of the leg.

The pallet leg is formed by an extruded plastic body, preferably with an elongated section, the leg comprising in its base a metal insert oriented in the largest dimension, which metal insert is leveled or protrudes relative to the leg body and which extends practically over the entire base of the leg.

[0031] Preferably, the leg comprises internal ribs embossed with the leg walls, the insert being interlaced in one of the ribs such that the loads can be transferred from the leg body insert.

[0032] Preferably, the leg comprises one or more metal inserts, parallel to each other or not.

[0033] More preferably, the insert or inserts have a section comprising a support portion rounded in their support zone and a rectilinear portion for stiffness.

[0034] Finally, the leg comprises external vertical ribs for stiffness.

DESCRIPTION OF THE DRAWINGS [0035] For a better understanding of the description, a set of drawing figures is enclosed, where, schematically and with the aid of non-limiting examples, a practical case of embodiment is shown.

Fig. 1 is a perspective exploded view of a quadrant of the pallet base according to the invention, it being possible to see its different base layers.

Fig. 2 is an enlarged view of the sector of Fig. 1.

Fig. 3 is a perspective view of a pallet according to the invention, mounted and with legs assembled.

Fig. 4 is a perspective view showing in a closeup how the edges of the honeycomb project, which protruding edges will serve to secure the covering sheets.

EP2767482 B1

Fig. 5 is a perspective view in close proximity to one of the openings designed for the legs, wherein a reinforcing wall can also be seen.

Fig. 6 is a view of the inverted base such that a change in the cross-section of the opening that forms the leg support surface can be seen.

Fig. 7 is a transverse view along a plane which passes through one of the openings which makes it possible to notice changes in the cross-section of the opening.

Fig. 8 is a top view across the horizontal cross-section of the pallet in such a way that a honeycomb structure and crossed reinforcements or beams can be seen that divide the pallet into four sectors.

Fig. 9 is a perspective view showing the stacking of two pallets.

Fig. 10 shows the inverted pallet with legs assembled.

Fig. 11 is a cross sectional view of the leg, wherein the shape of its contour and the shape of the ribs can be seen for stiffness and support of the metal insert.

Fig. 12 is a corresponding cross-section in a plan view.

Fig. 13 is a vertical cross-sectional view of the leg, wherein the section of the insert can be seen. Fig. 14 is a plan view of the leg.

Fig. 15 is another cross-sectional view of another leg plane.

Figures 16 to 19 show four different options for a perimeter connection project.

Figs. 20 and 21 show two vertical leg views, with external vertical ribs for stiffness.

DESCRIPTION OF THE PREFERRED EMBODIMENTS [0036] As shown in Figure 1, the invention generally relates to a base 1 for a pallet P that includes an inner plastics honeycomb structure 2, two metal sheets 3, 4 placed on each side of the inner material structure 2 plastic, which extend over the entire inner honeycomb structure and two outer plastic sheets 5, 6, adjacent to the metal sheets 3, 4.

[0037] In particular, according to the invention, the ends of the edges connecting the 7 honeycombs protrude above these cells, and the metal sheets 3, 4 are provided with through holes 8 for the passage of the ends of the edge 7 in such a way that it is possible to closely connect these ends to the outer ones. plastic sheets 5, 6. This connection is provided by welding, whereby it is necessary to maintain the continuity between the material of the ends and the outer plastic sheets.

[0038] The metal sheets have openings at all points corresponding to the edges of the honeycomb.

[0039] This structure allows, inter alia, mechanically stable holding of the pallet loaded on the rack during long periods of time without significant deformations due to viscoelastic shifting, which is one of the objectives of the invention.

[0040] The inner structure of the plastic honeycomb 2 has a lateral limit 2a that closes the peripheral cells, this side border 2a extending on each side to form a respective nesting frame and attaching the outer plastic sheets adjacent to the metal sheets.

[0041] All connections are made by welding in such a way that the plastic covering sheets are uniformly and tightly connected to the inner honeycomb structure, ensuring

EP2767482 B1 attaches to each other metal sheets that will be responsible for withstanding the bending of the pallet when it is subjected to high loads.

[0042] This lateral boundary was obtained from one element together with a honeycomb, which further guarantees a monolithic level of the pallet base.

[0043] The lateral border 2a, Figure 5, extends over a greater distance than the added thickness of the metal sheets and outer plastic sheets in such a way that it constitutes a lateral support ring for the loads present on the pallet.

[0044] For the implantation of the legs, fig. 3, holes 9 are provided.

[0045] These openings comprise reinforcing walls 11 connected to the honeycomb cells in such a way that, despite their interruption, they show sufficient thickness to guarantee the strength of the base.

[0046] As shown in the cross-section in Fig. 7 and in perspective in Fig. 6, the holes 9 have a cross-sectional change in such a way that they define a continuous support surface 12 for the legs 10.

[0047] The openings 9 and corresponding legs have, in the opening direction, an elliptical contour with two circular inlets on the nearest sides of the ellipse. This shape prevents stress accumulation and rotation of the leg in the hole towards the horizontal transverse axis.

[0048] As shown in Figs. 3 and 9, according to a particularly preferred variant, the base comprises nine substantially elliptic holes, four at the corners and directed towards the maximum dimension of the base, three in the central part facing towards the maximum base dimension, and the other two directed perpendicular to the others.

[0049] The difference in leg length allows the pallet to adapt to transport systems.

[0050] In particular, the longitudinal legs that are longer allow the pallet to travel on logistic roll and chain assemblies. Perpendicular assemblies make it compatible with roller guide systems.

[0051] As can be seen in the cross-section of Fig. 7, the walls of the openings are inclined to allow nesting accumulation of a series of pallets.

[0052] As can be seen in Fig. 8, two reinforcing beams 13, 14 are used in the internal structure, centered and crossed and closely connected to the honeycomb structure. These beams increase the stiffness of the base 1.

[0053] As can be seen in Fig. 9, the base comprises two inclined frames 15,16 on both of its short sides for nesting the forks.

[0054] The invention also relates to a pallet equipped with a base such as described herein and also with removable legs 10.

[0055] These legs comprise a metal insert 17 in their base, leveled or protruding above the leg body, and extending along virtually the entire length of the leg. In this way, the pallet can be occasionally supported on these inserts, allowing it to rest on a type of rack that contains two beams. This feature is critical. Without these inserts, with the pallet loaded and laid for some time on the rack on the beams, the legs on the occasional support could become deformed due to the viscoelastic behavior of the plastic. The result is the instability of the pallet and its inability to continue supporting the load on the rack. The inserts distribute loads and prevent these deformations, which allows for storage at a height for a long time even at high loads.

EP2767482 [0056] As can be seen in the cross section in Fig. 11, ribs were considered to ensure the transmission of forces within the legs.

[0057] These ribs guarantee the attachment of the insert and the distribution of loads carried by the leg.

Furthermore, their height inside the leg is determined so that a pallet arranged on top of a given pallet is supported precisely on the surface defined by the upper surface of the rib. This avoids jamming and provides space between the next pallet for the introduction of the forks.

[0059] To guarantee water drainage and avoid collecting it, the legs include drain holes 18 in their base, as shown in Fig. 11.

[0060] The leg pads have a section including a support portion rounded in the support zone and a rectilinear portion for stiffness. To guarantee centered support and even in cases of deformation by bending, rounding of the insert support surface in both directions is taken into account.

[0061] Figs. 20 and 21 show preferred embodiments of the legs, whereby the outer vertical ribs N for stiffness are provided.

[0062] With respect to the connection between the two outer plastic sheets 5, 6 with the peripheral edge of the base, as shown in Figs. 16 to 17, this can be done in two ways.

[0063] The connection to the plastic covers can be made with a circumferential border, as shown in Fig. 16, or aligned with it, as in Fig. 17.

[0064] When the connection is made to the peripheral edge, it is preferable to slightly raise it with respect to the vertical projection of the pallet, which is why the inclined portion is considered.

[0065] Figures 18 and 19 show another variation of a joint in which the corners of the sheets are circular and the projection is arranged between the honeycomb and the outer wall. In both cases, the perimeter border was taken into account, albeit in two different options, one with an incline and the other completely horizontal.

[0066] The connection to the vertically hanging circumferential border is made only in the upper part.

[0067] The leg 10 for the pallet P is formed by an extruded plastic body, preferably with an elongated section, which comprises a metal insert 17 oriented according to the largest dimension in its base, the metal insert 17 being leveled or superior to the leg body 10 and extending over practically the entire base of the leg 10.

[0068] The leg is made by embossing, and preferably has a longitudinal and hollow section, without internal ribs and insert.

[0069] As can be seen in the cross section of Fig. 11, the leg includes internal ribs embossed with the leg walls, and each insert is interlaced with the rib in such a way that the loads can be transferred uniformly over the rest of the ribs and from there onto the leg body. These inner ribs are vertical flat beams that connect the outer wall of the leg, e.g. one in the longitudinal direction and the other in the transverse direction.

[0070] In some cases, it may be necessary to use wider legs, in which case it may be contemplated to use two or more metal inserts 10, in parallel or not.

[0071] As can be seen in Fig. 13, the insert or inserts have a cross section including a rounded portion in the support zone and a rectilinear portion for stiffness.

[0072] In this way, despite the fact that the leg is slightly tilted, effective support is guaranteed by means of this rounded surface.

[0073] Finally, as can be seen in Figures 20 and 21, the leg comprises external vertical ribs N for stiffness.