GB2481143A

GB2481143A - Panel comprising an alveolar or pocketed core

Info

Publication number: GB2481143A
Application number: GB1109807.6A
Authority: GB
Inventors: Luigi Chiarion
Original assignee: Individual
Current assignee: Individual
Priority date: 2010-06-10
Filing date: 2011-06-10
Publication date: 2011-12-14
Also published as: ITPN20100015U1; FR2961075B3; FR2961075A3; GB201109807D0; DE202011050320U1

Abstract

A panel is formed by an internal core and two planar skins. The core has an alveolar, pocketed structure. The perimeter of the core is delimited by an edge structure which maintains the planarity of the two external surfaces. The skins extend over the entire width of the edge structure. The edge may be provided by rectilinear, elongate elements with quadrilateral cross section, of thickness substantially similar to the thickness of the core, the skins may extend to completely overlap the edge. Alternatively, the edge structure consists of an elongate U-shaped element applied on and around the edges of the core structure, so that the edges are contained within the U-shape, corners may be mitre cut. The core may be a single sheet of thermoplastic material, preferably polyethylene, formed into prismatic cells having sides at right angles to the plane of the wall, each cell being closed at one end and open at the other.

Description

"ULTRALIGHT PREFABRICATED WALL"

DESCRIPTION

The present invention refers to a prefabricated wall, particularly designed for the construction of furniture items, built with processes that make it possible to obtain an end product that perfectly combines the characteristics of particular lightness and strength, the whole combined with a surprisingly advantageous cost of production, as it relies on a substantially alveolar structure.

There are many well-known cases of furniture items built according to a structure known as being of "alveolar" type, in the sense that numerous zones or distinct portions of furniture items are defined from a planar plate, which zones are then bent and/or turned toward each other according to a prearranged pattern, so as to obtain a type of furniture item provided with various distinct shelves or compartments, that is easy to build, obtained by processing a single plate of material, and that for this reason is defined as being "of alveolar structure".

A typical example of this type of construction is offered by Patent EP 1 065 959 Bi, which illustrates a honeycomb structure, formed by a vertical and horizontal alignment of cells or "alveoli" made by suitably bending definite portions of a plate.

This solution is proven effective, easy to build and carry, and thus completely meets the objectives aimed at.

Moreover, the technology employed is traditional, and thus the materials used do not provide on their own any specific advantage, especially in terms of weight and cost of the material making up said plate.

Patent GB 803,259 discloses a solution for building a wall or a panel having a cellular structure. As shown in various levels of detail in the respective figures from 2 to 16, said structure is formed as a combination or juxtaposition of a plurality of separate and distinct layers or bands, that are shaped in a similar or specular manner; said distinct layers are then reciprocally connected, and the relative faces that adhere to each other are reciprocally glued together so as to guarantee their stability.

This process presents however problems of operation and cost, as it involves the preparation and positioning with great precision of a large number of distinct layers, that must moreover be glued with precision and great care.

In addition, the structure thus obtained is rather fragile and not very sturdy, as it is in fact consolidated only by the reciprocal gluing of the faces present in each layer, an intrinsically unsound and low-strength solution.

US Patent 2007/0256379 Al discloses the production of a composite panel formed by an internal foam structure and by the two external "skins" that enclose and strengthen said panel.

In this case, the structure is basically formed and consolidated by a plurality of geometrical elements or cells that extend from one skin" to the other. However, in this case, too, each cell must be made separately, and must also be mounted individually: an inevitable consequence of this situation is that the construction of the panel becomes more costly and complicated, and it effectively replicates the drawbacks described in the previous case.

Generally, the preference for furniture pieces of common and general use is for items having the characteristics of: -lightness; -strength; -substantial competitiveness and optimization of transportation costs.

These features are not all available at the same time in the present state of the art; in particular, there is a lack of a type of furniture item that combines the characteristics of lightness, sturdiness and easy assembling.

Therefore, it would be desirable, and it is the main objective of the present invention, to produce a prefabricated wall, in particular one characterized by great lightness without sacrificing strength, suitable to basically offer the above-mentioned objectives.

This objective is achieved by a wall built according to the accompanying claims.

Characteristics and advantages of the invention will become evident from the following description, given by way of non-limiting example, with reference to the enclosed drawings, wherein: -fig. 1 shows an external perspective view of a wall according to an embodiment of the invention; -fig. 2 illustrates a view of the wall of fig. 1 according to the relative cross section A-A; -fig. 3 illustrates the wall of fig. 2, but shown in an exploded view; -fig. 4 is an exploded view of a wall generally of the type of the previous figures; -fig. 5 is a view similar to fig. 2, in a different and improved embodiment of the invention; -fig. 5A shows the same view of fig. 5 but with the same portion of wall shown in an exploded view; -fig. 6 shows a perspective view of a pictorial type, and in a partial condition of disassembly, of a wall generally according to the previous figures; -fig. 7 shows an external perspective view of a different embodiment of a wall according to the invention; -fig. 8 is a view of the wall of fig. 7 according to the relative cross section B-B; -fig. 9 illustrates the wait of fig. 8, but shown in a partial exploded view in a definite phase of construction of the wall; -fig. 10 shows the wall of fig. 8, in the subsequent phase of construction; -fig. 11 illustrates a perspective exploded view of the wall in the embodiment of fig. 7; -fig. 12A is a view of the single sheet of thermoplastic material used to obtain the alveolar structure according to the present invention, in a preliminary shaping phase, and before it is folded in pleats as a concertina so as to close each individual cell; -fig. 12B shows an enlargement of the section according to the cross-section plane N -N of fig. 12A; -fig. 12C illustrates the cross section K -K of figure 12B.

With reference to figures 1 to 6, a wall of a furniture item according to the invention is formed by: -a plate of material having an internal alveolar structure 1, built preferably through a suitable processing of thermoplastic substances, which will be better explained hereafter; -two planar external skins 6, 7, each of which being suitable to be fixedly applied permanently, preferably with a gluing operation or by the application of heat on a respective external surface of said alveolar structure.

According to a first embodiment of the invention, and with reference to figures 1 to 6, the external perimeter of the alveolar structure I is delimited by an external edge 3, consisting of a plurality of distinct, typically rectilinear segments. Said segments, or more generally said edge 3, is shaped as a right prism, and preferably having a rectangular or square cross section; thus, one side face 10 of said edge 3 is located in front of and in contact with the corresponding face 11 of said structure I. In general, all the transversal dimension of said edge 3 has the same dimension "si" of the thickness "s" of said structure 1, so that, as shown in fig. 2, said edge 3 appears as a logical extension of the stiucture itself 1.

With reference to figures 3 to 6, said external skins 6 and 7 are sized so that, once arranged on the respective sides of said alveolar structure 1, they can extend exactly across the width h" necessary to also cover the respective other faces of the respective ones of said edges 3.

In this manner, a structure is produced that also offers, in addition to the above-mentioned characteristics of strength and simplicity, the quality of having two externally opposite and completely planar surfaces, due to the identical corresponding dimensions of the edge 3 and the structure 1, and due to their being completely covered by said skins 6 and 7. Advantageously, the external face 12 of the edge 3 is in turn covered by a respective profile 14, so as to mask said external face 12 and make it appear similar, or identical, to said skins 6 and 7.

With reference to figures 5 and 5A, an advantageous improvement can be easily achieved if one of said skins, for example the skin 7, is extended further so that said further extension may be bent so that the resulting edge may cover said external face 12 of the relative edge 3, thus immediately and easily obtaining said profile 14.

The invention can be carried out with a different embodiment, which differs from the previous solution due to the fact that it requires a simplified production process, and that it presents a different aesthetic aspect.

With the present solution, and with reference to figures from 7 to 11, the external edge is produced not by an internal element enclosed between said two skins 6 and 7, but by an elongate external element 33, formed in a "U" shape, and mounted onto a respective lateral portion 15 of one side of said alveolar external structure 1, and therefore also on said respective portion of the two external skins 6 and 7 that cover said lateral portion 15.

In order to avoid having the thickness of the sides of said U-shaped element 33 creating an undesirable step with respect to the planes on which the respective skins 6 and 7 lie, the same skins, together with said lateral portion 15 are put through a contraction process, preferably by means of a slight compression, as is clearly shown by the differences between figures 9 and 10, so that the thickness "s2" of the relative said lateral portion 15 becomes smaller than the thickness of the structure 1 in the central area of the latter, or in any case where it is not compressed.

The dimensions of the various elements involved, in other words said lateral portion 15, said skins 6 and 7, and said lateral portion 15 must be chosen and reciprocally coupled so that when said U-shaped element 33 is applied on a respective one of said lateral portions 15, as clearly shown in figures 8 to 10, the planes of the two skins 6 and 7 coincide with the planes of the corresponding sides 33A and 33B of the U-shaped element. With this process, a wall is obtained that, even if it includes said elements 33 on the edges of the latter, it still displays a surface profile "F" without noticeable steps, and therefore basically flat.

With reference to figures 7 and 11, and for the purpose of increasing the structural strength of the wall thus obtained, the same wall is formed as a four-sided element with right angles, and said U-shaped elongate external elements 33 are mounted on the respective external sides of the wall so that the separation lines "p1", "p2", ... are substantially aligned with the bisecting lines "Bs" that cut through the relative said right angles.

(Although it would be more correct to speak of separation planes, it is here preferred, on the basis of the drawings provided, to refer to the relative lines resulting from the intersection of said separation planes with the planes on which said skins 6 and 7 lie, which is a simpler and unequivocal solution.) In order to achieve the desired compactness of said alveolar structure 1, which is the necessary condition to also obtain the desired sturdiness and lightness of the wall as defined above, the alveolar structure 1, said two skins 6 and 7, the respective segments of said edge 3, and the possible profile 14, are fixedly engaged with each other through the most suitable processes and materials known in the art: these are mainly by gluing the facing and contacting surfaces, or by hot gluing.

Since these processes are known, no additional specifications will be given.

A further essential condition to obtain the desired characteristics of strength, economy and lightness of the wall of the invention lies in the technology of the materials and production of said alveolar internal structure 1 For this purpose, extensive trials have shown that the best solution of said internal structure consists of realizing it in accordance with the teachings of the Italian patent application No. PN2010A000032 dated 04.02.2010, filed by the same applicant, and to which reference is made for the sake of brevity.

Thus, said alveolar internal structure 1 must be obtained by suitably forming a single sheet of thermoplastic material, preferably polyethylene.

Said sheet of thermoplastic material must, moreover, be shaped so as to appear as a barrier or grid of prismatic cells having the respective sides at right angles to the plane of extension of said wall, substantially in agreement with the just-mentioned patent; and further, one of the bases of said cells is open or free of material, and the respective opposite base of the same cell is closed by a respective edge of said thermoplastic material.

By way of explanation and of better documentation for the reader, it is pointed out that other solutions have been disclosed tending to obtain an alveolar structure formed by the combination/association of a large number of cells, of prismatic and hexagonal type; such a solution is in fact disclosed in US Patent 6,726,974 Bi.

However, such solution consists in the suitable deformation, by a press-forming process of traditional type of a sheet of previously extruded thermoplastic material (see abstract: "A strip of material is plastically deformed perpendicular to the plane...').

Unlike that solution, the present invention is based on the technology of forming the sheet of thermoplastic material at the same time as the formation of the preliminary shape of the sides of the individual cells.

The technology of production of the preformed sheet consists of casting a film of thermoplastic substance, preferably polypropylene, in a semiliquid or gel state, on a forming cylinder rotating around its axis; the external shape of said cylinder is designed so that, by the combined effect of said shape and of the temperature of the cylinder, much lower than the temperature of the thermoplastic substance, the same substance is cooled and thus it consolidates on the surface of the cylinder, taking on the shape shown in figure 12A.

This technology is well known and therefore will not be discussed further.

In figure 12A it can be seen that said shaping forms not only the sides I-I, 1-2, 1-3, 1-4 of the prism that originates a respective cell, but also the two semibases bi and b2 (that are separated by respective segmentation lines Ti, T2, ..., also obtained on said sheet), when suitably disposed on the same plane, will become the completed base of the same cell.

In fact, to complete the structure, the sheet itself is pleated as a concertina along said segmentation Jines TI, T2, ..., so that the sides of one cell are suitably joined in a known manner, and the relative semibases take on their definitive planar shape.

Although this process is in itself known, it is pointed out that this process offers a double advantage with respect to the construction according to the prior art: a) in fact, each cell is lighter, as it is provided with a single base instead of two; and therefore the whole structure built with said cells also becomes lighter, but not less sturdy; b) moreover, the construction of the formed sheet is a process of continuous type, and therefore the cost of the alveolar structure is much lower than the cost of an alveolar structure obtained by making a large number of individual formed sheets, which then must be matched and joined with relative precision.

Thus it is explained and shown how the technology of production of the wall comprising an alveolar internal structure, of the type and with the characteristics specified above, provides evident and significant advantages, both in terms of performance and cost, compared with the solution proposed in the above-mentioned US Patent 6,726,974 Bi.

Claims

CLAIMS1) Uftralight prefabricated wall formed by an alveolar internal structure (1) and by two substantially planar external skins (6, 7), characterized in that: -the perimeter of said internal structure is delimited by an external edge (3) suitable to prevent altering the substantial planarity (F) of the two external surfaces of said wall; -and in that said two external skins (6, 7) extend over substantially the entire width (h) of said external edge (3).
2) Ultralight prefabricated wall according to claim 1, characterized in that: -said external edge (3) consists of an elongate element that is substantially rectilinear, firm, hollow or solid, with a quadrilateral cross section, having a thickness (si) substantially similar to the thickness (s) of said alveolar structure, and wherein one of the faces (10) of said edge is contiguous to a corresponding lateral face (11) of said internal structure, -and in that said external skins (6, 7) extend to where they completely overlap said edge (3).
3) Ultralight prefabricated wall according to claim 2, characterized in that the external face (12) of said edge (3) is covered by a continuous profile (14), which preferably borders the entire external perimeter of said wall.
4) Ultralight prefabricated wall according to claim 3, characterized in that said continuous profile (14) consists of a suitable extension of one (7) of said external skins.
5) Ultralight prefabricated wall according to claim 1, characterized in that said external edge consists of an elongate U-shaped element (33) suitable to be applied on and around a corresponding lateral portion (15) of said alveolar internal structure, so that said structure is contained within the U-shaped concavity of said elongate element (33).
6) Ultralight prefabricated wall according to claim 5, characterized in that -said lateral portion (15) of said alveolar internal structure (1) has a relative thickness (s2) that is smaller than the thickness (s) of the respective structure in the relative central area; -that said skins (6, 7) are reciprocally set nearer to each other in the external areas corresponding to said lateral portion (15), so as to adhere to said areas and overlap them, -and in that said U-shaped element (33) is applied on and around said respective external areas.
7) Ultralight prefabricated wail according to claim 6, characterized in that said elongate elements formed in a "U" shape, when contiguous, are coupled to each other through coupling forms at right angles, wherein the separation line between two contiguous elongate elements (p1, p2, ...) is substantially aligned with the bisecting line (Bs) of said right angle.
8) Ultralight prefabricated wall according to any one of the previous claims, characterized in that said alveolar internal structure (1) is achieved by forming a single sheet of thermoplastic material, preferably polyethylene.
9) Ultralight prefabricated wall according to claim 8, characterized in that said sheet of thermoplastic material is shaped according to prismatic cells having the respective sides at right angles to the plane of extension of said wall.
10) Ultralight prefabricated wall according to claim 9, characterized in thatSone of the bases of said cells is open or free of material, and the respective opposite base of the same cell is closed by a respective edge of said thermoplastic material.