WO2006032815A1 - Plastic reinforced handling pallet - Google Patents

Abstract

The inventive plastic reinforced handling pallet (1) consists of a top structure (10) and a bottom structure (20) which are substentially identical and inserted inside each other, wherein each structure (10, 20) forms a substentially rectangular tray (11, 21) provided with legs (12, 22) or pads projecting under the tray, the tray (21) of the bottom structure (20) comprises one or several grooves (24) which are projected under the tray and in each of which a rigid reinforcing rod is disposed in such a way that it is embedded between the trays (11, 21) of the two structures (10, 20) when they are inserted into each other.

Description

 Reinforced handling pallet made of plastic

The invention relates to a reinforced handling pallet made of plastic material which generally comprises a substantially rectangular shaped plate with feet or studs protruding under the plate. The invention also relates to a method of manufacturing such a pallet.

Handling pallets for the transport and storage of bottles for example are traditionally made of wood. However, as these pallets can easily be soiled, contaminated or deteriorated, especially by liquids, powders, fungi or bacteria, they can not be used when it is required a great cleanliness, for example in hospitals, laundries as well as agro-food industries such as biscuits, chocolate shops, butchers, etc ... It is then necessary to have pallets whose surface is at the same time little absorbent, washable and resistant to abrasion.

To solve this problem, metal pallets and plastic pallets have been created. Metal pallets are little used because they are heavy and expensive. Plastic handling pallets are generally obtained by injection molding. By way of examples of plastic handling pallets may be mentioned the known embodiments of the French patent documents FR-2070367, FR-2172412, FR-2259023 and also by the documents WO-96/24529, US-5341748, DE-2306869, DE-2720364, EP-231792, EP452726 and finally AT-307980. Such plastic pallets can be relatively expensive because of the large amount of plastic material needed to obtain a sufficiently rigid structure.

The present invention aims to provide a solution to improve the overall strength of handling pallets with a lesser amount of plastic to use. For this purpose, the subject of the invention is a reinforced handling pallet made of plastic material, characterized in that it consists of a substantially identical upper structure and lower structure and nested one inside the other, each structure forming a substantially rectangular tray with feet or studs protruding under the tray, the tray of the lower structure further comprising one or several grooves projecting under said plate in each of which is arranged a rigid reinforcing bar so that the reinforcing bar is embedded between the plates of the two structures when they are fitted one inside the other. The rigid reinforcing bars therefore make it possible to improve the mechanical and dynamic strength of the pallet, which can therefore, for an equal strength, be manufactured with a smaller amount of plastic material.

According to a particular embodiment of the pallet according to the invention, the two structures of the pallet each comprise three rows of feet and the pallet comprises two parallel grooves each extending longitudinally between two adjacent rows of feet.

The pallet according to the invention may comprise reinforcement bars made of wood, or metal or fiberglass. The invention also extends to a method of manufacturing a pallet as defined above, comprising the following steps:

the upper and lower structures are formed by thermoforming or injection molding,

the reinforcement bars are inserted into the grooves of the lower structure,

the upper and lower structures are nested one inside the other and they are welded to each other by ultrasonic or mirror welding.

An example of a particular embodiment of the pallet according to the invention is described in more detail below and illustrated by the drawings. This description is given as an indicative and non-limiting example of the invention.

Figure 1 is a perspective view of the pallet according to the present invention in an exploded form.

Figure 2 is a top view of the upper structure of the pallet according to the present invention.

Figure 3 is a top view of the lower structure of the pallet according to the present invention.

Figure 1 shows a pallet 1 according to the invention in an exploded form. This pallet 1 consists of an upper structure 10, a lower structure 20 and two stiff reinforcement bars 2 or stiffeners. The upper and lower structures 20, which are more visible respectively in FIGS. 2 and 3, are made of plastic, more particularly HDPE (High Ethylene Ethylene PolY) or copolymeric polypropylene. The shapes of these structures are obtained by thermoforming or by injection into a mold. The upper and lower structures 20 each respectively comprise a substantially rectangular plate 11, 21 and nine feet 12, 22 or pads arranged here in three rows 13a, 13b, 13c, 23a, 23b, 23c and projecting under the plate 11, 21 . The legs 12, 22 are hollow, closed at the bottom and open at the top of the side of the plate 11, 21. The upper and lower structures 20 are shaped substantially identically, so that the upper structure 10 can fit perfectly into the lower structure 20, ie so that the legs 12 of the structure upper 10 fit into the hollow feet 22 of the lower structure 20 and the plate 11 of the upper structure 10 is applied against the plate 21 of the lower structure 20.

Two parallel grooves 24 are further formed in the lower structure 20. Each groove 24 extends longitudinally in the rectangular tray centrally between two rows of adjacent legs 23a, 23b, 23c, stopping close to the edges of the tray 21 and projecting below the plate 21. The grooves 24 form preferably elongate parallelepipedal housing whose only upper side is open in the plate 21. The reinforcement bars 2 are cut so as to be housed in the grooves 24. When the reinforcement bars 2 are inserted into the grooves 24 of the lower structure 20, the upper structure 10 is engaged in the lower structure 20 and these two structures 10,20 are welded together, by all their surfaces in contact, by welding with ultrasound or by poly-fusion welding to the mirror. Therefore, the reinforcement bars 2 are embedded and locked between the lower structure 20 and the upper structure 10. The legs 12,22 of the upper 10 and lower 20 structures together form the feet of the pallet, and the plates 11, 21 of the Upper and lower structures 20 together form the pallet plate. The stiff reinforcement bars 2 serve to stiffen and reinforce the mechanical and dynamic strength of the overall structure of the pallet. plastic material, this overall structure can thus be stripped. A pallet according to the invention requires a small amount of plastic material. The invention will be particularly advantageous when the plastics used have a very high cost such as food grade plastics, or class fireproof.

The size, the shape and the number of grooves 24 and reinforcement bars 2 depend on the strength, the weight and the cost sought for the pallet 1, as well as the material of which the reinforcing bars 2, which may be wood, metal, fiberglass or other synthetic material.

As can be seen in FIGS. 2 and 3, the feet 12, 22 of the pallet 1 have a base of substantially oblong shape which extends in the same direction as the reinforcing bars 2, so as to give the pallet better rigidity. Pallets 1 according to the invention can stack one inside the other because their feet 12, 22 are hollow and the protuberances formed below the plate 11, 21 by the groove 24 serve to limit the embedding of pallets and thus to facilitate their handling.

The invention is applicable to various types of plastic pallets: single-use pallets or reusable pallets, pallets stackable or not, pallets with single feet or pads, or pallets with soles, etc ...., these pallets can beings naturally of any size, in particular of standardized dimensions.

Claims

1 / Pallet (1) reinforced handling plastic, characterized in that it consists of a lower structure (10) and a lower structure (20) substantially identical and nested one inside the other, each structure (10, 20) forming a substantially rectangular plate (11, 21) with feet (12, 22) or studs projecting under the plate, the plate (21) of the lower structure (20) comprising one or more grooves (24) projecting under said plate in each of which is disposed a rigid reinforcing bar (2) so that the reinforcing bar (2) is embedded between the plates (11, 21) of the two structures (10.20) when they are nested one inside the other. 2 / pallet according to claim 1, wherein the reinforcing bars (2) are wood. 3 / pallet according to claim 1, wherein the reinforcement bars (2) are metal. 4 / pallet according to claim 1, wherein the reinforcement bars (2) are fiberglass. 5 / pallet according to one of claims 1 to 4, wherein the two structures of the pallet each comprise three rows of feet and the pallet comprises two parallel grooves each extending longitudinally between two adjacent rows of foot. 6 / pallet according to one of the preceding claims, wherein the feet (12,22) have a substantially oblong base which extends parallel to the reinforcing bars (2). Palette according to one of the preceding claims, wherein the feet (12,22) are hollow and open on the side of the tray. 8 / A method of manufacturing a pallet according to one of the preceding claims, comprising the following steps: the upper (10) and lower (20) structures are formed by thermoforming or injection molding, the reinforcement bars (2) are inserted into the grooves of the lower structure, the upper and lower structures are fitted into one another in the other and welded together by ultrasonic or mirror welding.