"A PLASTIC CASE"

TECHNICAL FIELD

The present invention relates to plastic cases intended for transportation and storage of products such as fruits and vegetables. Most particularly, the case according to the present invention provides the use, in at least one of the walls thereof, of webs comprised of a plastic or textile material.

BACKGROUND OF THE INVENTION Due to its low cost, paperboard is widely used to make cases intended for transportation and storage of fruits and vegetables. Notwithstanding the fact of being extremely light in weight, paperboard cases evidence various disadvantages in connection with their use, such as low strength and limitations relative to their design, stacking ability (particularly in moist environments) and reproducibility. Furthermore, such cases are difficult to assemble, exhibit poor thermal conductivity and are highly susceptible to contamination.

In order to solve such problems there were developed cases made of plastic or synthetic resins, whereof the majority are necessarily returnable due to their high manufacturing cost. Such characteristic implies that the reused cases be hygienized and affects logistics processes, rendering their use unfeasible for long-distance transportation.

In US patent No. 4,105,117, for example, there is disclosed a returnable plastic case, processed by injection into a single piece, comprising movable support rods that allow the engagement or nesting thereon of an overlying case according to their position.

Similarly, a plastic case, with an inner wall configuration modified to minimize any damage to the product stored therein, is described in US patent No. 5,395,009.

Said cases evidence the disadvantages of not being able to be disassembled and being excessively heavy.

Patents Nos. EP 0 751 074 and US 6,793,085, on the other hand, describe plastic cases that can be disassembled and are comprised of 5 parts, where the side parts are foldable.

Although they can be disassembled, the cases described in the said patents evidence complex structures and manufacturing molds, in addition to also being quite heavy. Furthermore, such cases do not provide comfortable storage to the material carried therein, causing a requirement of inner packaging means. In particular, the case defined in US patent No. 6,793,085, due to having closed side panels, does not provide proper refrigeration and aeration to the product stored therein.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a plastic case that may be able to advantageously replace paperboard cases for transportation of products.

One other object of the invention is to provide a lightweight plastic case that may provide comfortable containment, adequate heat exchange and proper aeration to the product stored in the same, and that may be

assembled/disassembled in a fast and simple manner.

In order to achieve such objects, the present invention provides preferably a process of injection over a core ("in mould labelling") whereby the plastic case is injected, in an open configuration, over a plastic or textile web, which latter shall constitute at least one of the side walls and/or the base of the case.

Ideally, the case that constitutes the object of the present invention will be of a substantially lighter weight than a paperboard case of equivalent size, which in addition to rendering the transportation of products easier, renders the use thereof economically feasible in non-returnable usage.

In a preferred embodiment of the present invention, the case is injected to form a single molded article.

In one other preferred embodiment of the present invention, the injection-molded article is structured by providing pins in support elements arranged on the edges of the walls.

In yet another preferred embodiment of the present invention, all the parts that comprise the case when assembled are made of the same material.

DESCRIPTION OF THE FIGURES The characteristics and advantages of the invention will be better understood by means of the description of a specific embodiment thereof, which is given by way of example and is not intended to limit the invention thereto in

any manner whatsoever, and of the figures referring to the same. In order to allow the visualization of the various elements that constitute the case, the web is shown only in Figures 3, 5a to 5m and 9.

Figure 1 is a top view of the open article as removed from the mold.

Figure 2 is a detailed top view of two side walls of the open article.

Figure 3 is a view of two side walls ready to be engaged by the pin.

Figure 4 is a view showing two side walls assembled to one another.

Figures 5a to 5m show the entire process of assembly of the case.

Figure 6 is a view showing cases of different sizes in a stacked configuration.

Figure 7 is a detailed view of the device that allows the stacking of cases of different sizes.

Figure 8 is a perspective view of the assembled article.

Figure 9 is a detailed view showing the web used for the bottom of the plastic case.

Figure 10 depicts the strut with T-shaped cross section that is

preferably used in the case structure.

DETAILED DESCRIPTION OF THE INVENTION

Figure 1 shows a single injection-molded part 1 upon removal from the mold. Although there are shown 4 walls, it should be understood that the use of at least 2 walls could be applicable. In the same manner, although a single part provides a gain in productivity and avoids the wear caused by contact among the elements, there could be used as well parts comprised of separate elements without thereby departing from the scope of the present invention.

The part as depicted in Figure 1 consists in the side walls 10 and the base 11 with tabs 30 provided at the intersection of the said walls 10 with the base 11, such tabs acting as hinges during assembly. The structure of the article 1 is completed with the injection thereof over a web 40 (not shown in that figure), in order to incorporate the same to the said walls. Preferably, as may be noted in Figure 10, the structure of the article is provided by using struts with a T-shaped cross section in order to form a frame to place the web 40.

The use of the webs 40, in addition to improving the heat exchange and aeration inside the case and providing enhanced storage comfort for the product therein, is the main factor to account for the decreased weight of the case obtained in accordance with the present invention.

Figure 2 shows a preferred detail of the elements that provide the structure of the case. The edge of the illustrated article shows a supporting surface 55 and two side walls 10, one of these having three lugs 51 and a hinged fastening surface, and the other having four recesses 52 and three openings 54. It

should be understood that any number of lugs, openings and recesses could be used. Similarly, the positioning of the said elements of the article may be varied without however departing from the scope of the invention. Having in view the fact that there may be used multiple walls, the sole restriction to the configuration of such elements is that the ends of two distinct side walls that meet during assembly should alternately comprise the lugs or the openings.

The steps of the process of assembly of the article may be viewed in Figures 5a to 5m. The side walls 10 are folded such that the lugs 51 pass through the openings 54. Thereafter, a pin 20 is inserted through the channel formed by the lugs 51 and recesses 52 until reaching the supporting surface 55, whereupon it is fastened by the engagement of the fastening surface 53 thereon. Figure 3 is a detailed view showing two walls 10 ready to receive the pin 20, while Figure 4 shows the same wall upon engagement of the pin 20.

Therefore, the process of assembly/disassembly of the article 1 is rendered simple and fast, which in addition to facilitate the use of the case, contributes to the reduction of the overall weight thereof.

In a preferred embodiment, the pins are inserted on the outer sides of the side walls 10, thereby avoiding any damage to the product stored in the case.

In yet another preferred embodiment, the pins 20 may act as supports for stacking the cases when the latter are full (Figure 6). Special devices 60, optionally provided at the sides, may also be used to stack cases of different sizes (Figures 6 and 7).

Figure 8 shows the assembled case according to all the preferred embodiments described hereinabove. There may also provided, as might be needed, the use of a lid, which may integrate the single part that constitutes the case or may be a separate element that is added to the case after the same is assembled. Similarly to the side walls and the base, the lid may comprise a web 40.

In another preferred embodiment of the present invention, in order to facilitate the manufacture and recycling of the case, all the parts used to provide the same are made of one same material, preferably polypropylene, biopolymer or HDPE (high density polyethylene).