FR2940792A1 - Modular carton pallet for transporting load, has feet glued to load carrying plate by expandable adhesive, where each foot is tightly assembled in bore of lower panel of plate, and diameter of foot is larger than that of bore - Google Patents

Abstract

The pallet (1) has feet glued to a load carrying plate (2) by an expandable adhesive, where the plate includes two counter-glued carton upper and lower panels (20, 21) having different densities. Each foot (3) is tightly assembled in a bore (23) formed in the lower panel of the plate, where diameter (D1) of the bore is less than a diameter (D2) of the foot. The feet are formed by circular tubes made of compact carton, where each foot has an end comprising a chamfer (30). The bore has a height equal to thickness of the lower panel, and includes an inlet chamfer (24).

Description

CARTON TRANSPORT PALLET

Technical Field: The present invention relates to a carton transport pallet comprising at least one load plate and feet glued to the load plate, the load plate comprising at least two laminated cardboard boards of different densities.

Prior art:

It is known that cardboard pallets advantageously replace wooden pallets thanks to their low weight improving their handling. The weight ratio of a cardboard pallet to a wooden pallet can be up to about 1/10.

This weight gain improves both working conditions and productivity. However, the use of this type of pallet faces a prejudice that consists in believing that a cardboard pallet is much less resistant than a wooden pallet.

Some cardboard pallets are for single use. They are not strong enough and must be discarded or recycled after their first use. These single-use pallets are not economically viable. It is therefore sought to produce more resistant cardboard pallets so that they can be used several times, and to reduce their manufacturing cost to make them economically more attractive.

On the other hand, the elements which make up the cardboard pallets being generally assembled by gluing, the mechanical rigidity of the obtained cardboard pallets is not sufficient in comparison with that of the wooden pallets. It happens in particular that the feet deform and peel when the pallets are handled under load, or slid on a surface.

Some paperboard pallets are made from U-sections assembled by interlocking in notches and the legs have a square section to fit inside the crosspieces to which they are glued. This method of construction is complex to implement, does not offer a continuous transport surface, nor sufficient strength, the feet nested in the sleepers can easily take off.

Publication EP 853 047 illustrates a pallet of this type, the load-bearing tray of which consists of two laminated cardboard panels having different densities and whose feet are fitted into a bore made in the lower panel of the front load-bearing tray. to be glued hot. It is specified that the drilling has a diameter equal to or slightly greater than the diameter of the feet. Thus, the fitting of the foot in this hole does not form a tight fitting. In addition, the glue used is a hot glue that requires a specific heating device, which generates additional costs.

No solution is satisfactory. Presentation of the invention:

The present invention aims at overcoming these drawbacks by proposing a very high quality cardboard transport pallet, having a high mechanical strength, offering increased rigidity, at a competitive cost price, configurable according to the needs, which can be reused several times. times, and can be recyclable.

For this purpose, the invention relates to a transport pallet of the kind indicated in the preamble, characterized in that each foot is mounted tightly in a bore made in the lower panel of said load-bearing plate, the diameter of said bore being less than the diameter of said foot, and in that the feet are glued to said load carrying tray by means of an expandable glue.

The feet may be formed of circular tubes of compact cardboard, at least one end of which may comprise a chamfer.

The lower panel of the load-bearing tray may consist of a low-density, multi-corrugated corrugated cardboard, and the top panel of the load-bearing tray may be made of a high density compact carton. The holes may have a height substantially equal to the thickness of the lower panel and have an input chamfer.

The feet are preferably distributed under the load-carrying tray so as to provide passages for the forks of a hoist, these passages being able to be arranged in both perpendicular directions.

Said pallet transport may include cross-ties under the feet and extending over at least one longitudinal or transverse dimension of the pallet, these cross-members forming skis and being assembled to said feet by stapling and / or gluing.

The feet may be tightly mounted in a bore made in said sleepers, the diameter of the bore being less than the diameter of the foot, and the feet being glued to the sleepers by means of an expandable glue.

Depending on the load to be carried, the feet arranged at the longitudinal ends of said pallet transport can be doubled. The transport pallet may be modular, the number and arrangement of the feet being determined according to the loads to be carried.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention and its advantages will appear better in the following description of an embodiment given by way of non-limiting example, with reference to the appended drawings, in which: FIG. A pallet according to the invention, and FIG. 2 is a sectional and exploded view of the pallet of FIG.

Illustrations of the invention and best way to achieve it:

Referring to the figures, the transport pallet 1 according to the invention comprises a load-carrying tray 2 formed of at least two panels 20, 21 solid of cardboard laminated with different densities, and in particular an upper panel 20 of compact cardboard with high density and a lower panel 21 of corrugated cardboard with low density and with several flutes 22, for example with triple flutes or two double inverted or crossed flutes. Of course, the load plate 2 may have a number of laminated panels greater than two. Preferably, the grooves 22 of the bottom panel 21 will be oriented in a direction perpendicular to the direction of entry of the forks of a hoist.

The transport pallet 1 has feet 3 reported under the load plate 25 2 by nesting and gluing. These feet 3 are cut into sections in a compact cardboard tube. The number and arrangement of the feet 3 are determined according to the loads to be carried. The height of the feet 3 is determined according to the height of the forks of a hoist. Preferably, the feet 3 are arranged in a grid pattern to evenly distribute the load over the entire surface of the transport pallet 1, and leaving free passages P for the forks of a hoist. These fork passages P are advantageously provided in the two perpendicular directions thus allowing four entries E on the four sides of the transport pallet 1. Depending on the loads to be carried, the feet 3 can be doubled in the end zones of the pallet This simple possibility to implement avoids the bending of the load plate 2 in case of significant cantilever.

The invention is distinguished by the fact that each foot 3 is mounted tightly in a bore 23 made in the bottom panel 21 of the load plate 2, the diameter D1 of the bore 23 being slightly less than the diameter D2 of the foot 3. Thus, the feet 3 are mechanically clamped in the holes 23, even without glue. To facilitate the interlocking of the feet 3, it is possible to make a chamfer 30 at the corresponding end of the feet 3 and / or a chamfer 24 at the entrance of the holes 23. Before fitting the feet 3 into the holes 23, it deposits an expandable adhesive, such as a polyurethane glue, which has the advantage of swelling and spreading around the foot 3, at the bottom and around the hole 23 by filling the voids, as well as inside the holes. lateral cells 25 created by the pierced corrugations of the lower panel 21, providing additional mechanical attachment. The result obtained is surprising because it makes it possible to obtain a very rigid mechanical assembly that is resistant to the shocks of the forks during the handling of the loaded transport pallet, or to any other shock.

The transport pallet 1 is completed by ties 4 reported under the feet 3 by gluing and / or stapling, and extending over at least one longitudinal or transverse dimension of the pallet 1. These cross members 4 are made from flat profiles in compact cardboard and form skis promoting the sliding of the pallet 1 on a support or on another pallet. They particularly promote the racking of the pallets 1. They are preferably arranged in the direction of the length of the pallet 1 which corresponds to the direction of introduction of the forks most commonly used. These sleepers 4 are not essential but provide an additional functional element to the transport pallet according to the invention. In addition, they provide additional mechanical support at the base of the feet that balances the tensions during the passage of the forks and add rigidity to the entire pallet. Possibilities of industrial application:

The transport pallet 1 according to the invention consists exclusively of panels and cardboard tubes of different densities obtained by known industrial processes, and assembled to achieve a high level of mechanical strength, to withstand a high static load of the material. order of 750 kg and a dynamic load of the order of 600 kg. These elements are determined according to the loads to be carried and make it possible to design transport pallets on demand, modular and adapted to the case by case. In addition, the cardboard elements are treated against surface moisture, and the adhesives used are moisture resistant, thereby increasing the pallet's performance, moisture resistance, and reusability.

An example of a method of manufacturing a transport pallet 1 according to the invention 20 is now described, this example may vary according to the constraints and needs.

Phase A: Before making the load plate 2, the lower panel 21 is drilled at the defined locations to position the feet 3, the hole saw or the like according to a diameter D1 slightly smaller than the diameter D2 of the tubes intended to form the feet 3. This bottom panel 21 being made from a corrugated cardboard with several grooves 22, the holes 23 made from one side to the other cut these grooves 22 creating around the holes 23 of the lateral cells 25.

Phase B: The entire surface of the upper panel 20 is coated with a glue 30 specially adapted for lamination of cardboard, for example a white acrylic glue, the lower panel 21 previously cut is applied thereto and this assembly is pressed until complete drying of the glue, which is visualized when the glue becomes colorless. It is important to glue the entire surface of the top panel 20 to ensure a flatness of the load plate 2 and to avoid voids or air pockets between the holes 23.

Phase C: In each piercing 23 is deposited an expandable glue, for example a polyurethane glue, and each foot 3 is fitted into force in each piercing 23 so as to obtain a tight fitting of the feet 3 in the load-carrying tray 2. during drying, the glue swells between the outer surface of the feet 3, the bottom and the inner surface of the holes 23 and is housed in the lateral recesses 25 of the grooves 22 of the lower panel 21, thus creating a mechanical catch which considerably strengthens the resistance mechanical assembly of the feet / load panel.

Phase D: The cross members 4 are assembled below the feet 3 in the direction of the length of the transport pallet 1 with a hot glue for example deposited with the gun, supplemented or not with a stapling. One can also use the same technique of assembling the feet to the load bearing tray: the feet can be mounted tight in a bore made in the sleepers, the diameter of the hole being smaller than the diameter of the foot, and the feet can be glued to the sleepers by means of an expandable glue.

It is clear from this description that the invention achieves the goals set and in particular to obtain a cardboard transport pallet that offers exceptional mechanical rigidity and not achieved to date by other types of cardboard pallet known. The present invention is not limited to the embodiment described but extends to any modification and variation obvious to a person skilled in the art while remaining within the scope of protection defined in the appended claims.

Claims (11)

Revendications1. Carton transport pallet (1) having at least one load plate (2) and feet (3) adhered to the load plate, the load plate (2) comprising at least two panels (20, 21) laminated cardboard of different densities, characterized in that each foot (3) is mounted tightly in a bore (23) made in the lower panel (21) of said load-bearing tray (2), the diameter (D1) of said bore ( 23) being smaller than the diameter (D2) of said foot (3), and in that the legs (3) are glued to said load-bearing tray (2) by means of an expandable glue. 2. Transport pallet according to claim 1, characterized in that the feet (3) are formed of compact cardboard circular tubes, at least one end comprises a chamfer (30). Transport pallet according to claim 1, characterized in that the lower panel (21) of the load plate (2) consists of a low density, multi-corrugated corrugated cardboard (22), and that the upper panel (20) of the load plate (2) consists of a high density compact cardboard. 4. Transport pallet according to claim 3, characterized in that said bores (23) have a height substantially equal to the thickness of the lower panel (21) and comprise an inlet chamfer (24). 5. Transport pallet according to claim 1, characterized in that said feet (3) are distributed under the load plate (2) so as to provide passages (P) for the forks of a hoist, these passages being arranged in both perpendicular directions. 8 6. Transport pallet according to claim 1, characterized in that it comprises crosspieces (4) attached under the feet (3) and extending over at least one longitudinal or transverse dimension of the pallet, these sleepers forming skis . 7. Transport pallet according to claim 6, characterized in that said crosspieces (4) are assembled to said feet (3) by stapling. 8. Transport pallet according to claim 6 or 7, characterized in that said sleepers (4) are assembled to said feet (3) by gluing. 9. Transport pallet according to claim 8, characterized in that said feet (3) are mounted tightly in a bore made in said sleepers (4), the diameter of said bore being less than the diameter of said foot, and in that the feet are bonded to said sleepers by means of an expandable glue. 10. Transport pallet according to claim 1, characterized in that the feet (3) disposed at the longitudinal ends of said pallet transport are doubled. 11. Transport pallet according to any one of the preceding claims, characterized in that said pallet (1) is modular, the number and arrangement of the feet (3) being determined according to the loads to be carried. 15