STRENGTHENED PLASTERBOARD PANEL PREFERABLY OF THE TYPE USED TO MAKE WALLS, PARTITIONS, FALSE CEILINGS AND COATINGS IN GENERAL

TECHNICAL FIELD

The present invention relates to the realisation of prefabricated building material . Particularly this invention concerns a strengthened plasterboard panel used for carrying out partitions, false ceilings and coatings in general .

BACKGROUND ART

It is known that the plasterboard panels are frequently used in the building field to make walls, partitions, false ceilings and coatings in general. These plasterboard panels are constituted by a layer of chalky material whose surfaces are covered by cardboard sheets. The plasterboard is commonly made in plates with standard width of 120 centimetres and of different thickness. The plates have not perfectly parallel edges: generally it is declared a tolerance of +/- 5 millimetres. The production of panels that have a width of 90 centimetres, is limited to the sector of the "do-it-yourself." The plasterboard panel compactness derives from the cardboard superficial layer and it is therefore lost when this latter is cut. Besides the jagged

edges of the panel must be carefully stuccoed. For such reasons the plasterboard panels are sold intact and then cut during their installation.

The fitting up of the panels is performed exclusively by specialised workers, since the installation is complex and requires both specific equipments and procedures diverging from those known by masons and carpenters. Accordingly, also the marketing of the plasterboard is reduced to few distributors.

Another drawback of the known plasterboard panels is that they have not enough rigidity and sturdiness. For this reason, they require a suitable support structure, which is commonly constituted by uprights extending along its height and not spaced too much. The limited thickness of the plasterboard panels and the insufficient consistence of the material allow the carrying out of walls unable to support wall units or heavy articles, mainly because of the difficulty of locating the uprights after the puttying. Moreover it is very difficult to replace a broken panel after its installation.

The object of the present invention is to make wall panels, partitions, false ceilings and coatings in general that, even if they include a cheap material like the plasterboard, they have suitable characteristics of rigidity, sturdiness and finish, so as to allow an easy and quick installation and the possibility of changing a broken element, extending their installations to workers not so skilled and without particular equipments.

Accordingly it is possible to extend the

application field of the plasterboard to a broader market, to maker's, distributor's and user's advantage.

DISCLOSURE OF THE INVENTION

The desirable characteristics are achieved by means of plasterboard strengthened panel, preferably of the type for making walls, partitions, false ceilings and coatings in general, being said panel of the type with chalk plate coated on both main surfaces with a coating cardboard layer and being characterised in that said panel has side portions, carried out by means of preventive parallel millings of couples of "V" shaped grooves, with these latter crossing the said chalk plate along its thickness, without cutting the said coating cardboard layer, that, remaining perfectly intact, protects and finishes up the edges of the cited panel, said edges being defined by the middle portions included between each cited couple of grooves as a consequence of folding the cited side portions onto themselves and onto the inner surface of the cited panel and of their fixing to said surface.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is now described in detail, with reference to the enclosed drawings illustrating the possible embodiments, by way of example in which:

- figure 1 shows a top view of a plasterboard panel, with parallel millings;

- figure 2 shows a top view of the completed panel , with the folded and glued side portions; - figure 3 shows a perspective view of completed panel;

- figure 4 shows a sectional view of a wall coated with the panels of the present invention;

- figure 5 shows a top view of a partition portion; - figure 6 shows a top view of a wall portion carried out with box-shaped fixed joint panels; figure 7 shows a sectional view of a false ceiling; figure 8 shows a perspective view of a panel designed to be suspended as that of figure 7; figure 9 shows a top view of the unfolded panel according to a second embodiment;

- figure 10 shows a top view of the finished panel of figure 9. - figure 11 shows a perspective view of the finished panel of figure 9.

BEST MODE OF CARRYING OUT THE INVENTION

Referring to figure 1, the numeral 1 refers to a plasterboard panel, having side portions 3 carried out by means of preventive and exact millings of grooves 2 which lay two by two to a determined distance from the edges of the panel 1. The grooves 2, carried out by means of precision machines, are perfectly parallel, have transversal "V" shaped

section and cross the panel along its thickness, leaving intact the external cardboard, also in correspondence of the middle portion 13 of the material, that will constitute the strengthened panel edges.

Therefore the side portions 3 are bent down onto themselves and toward the inner surface of the panel 1 to which they are fixed, for instance by gluing. The strengthened panel 1 shown in figures 2 and 3, has the following features: perfectly calibrated width, resulting from the exact parallel millings; rigidity and notably increased sturdiness, by virtue of the presence of the folded side portions 3, doubling the thickness of the strengthened panel edges, with consequent possibility of making half height walls that were previously cut and then ready for the assembling, or walls independent from existing walls; - perfect integrity and finish of the edges, coated by the cardboard sheet, with the consequent possibility of approaching panels without the need of puttying and with the facility of locating the rear uprights, disposed in correspondence of the junctions;

- possibility of being pierced by ordinary drills in correspondence of the double thickness side portions and of achieving a satisfactory fastening with ordinary screws of suitable length; - possibility of being easily dismounted or replaced, in case of breakage;

- possibility of being carried out in different sizes

and delivered ready to be used, also with possible PVC or wall paper coatings or the like.

The described panels could be used for coating a wall 4, as in figure 4. In this case the folded side portions 3 act as supports and spacers, allowing the coating of broad surfaces without interposing accessory elements.

For making a partition, the panels are positioned accordingly to figure 5, interposing the uprights 5, of wood or metal and of desired thickness, and fixing the strengthened panels by means of screws thereto, by virtue of greater sturdiness of the double thickness of the side portion 3. Two panels 1 could be joined previously so as to achieve box-shaped modules designed to the carrying out of partitions of retardant fire type and modular fixed joint type as shown in figure 6. Each module is formed by two faced panels 1 and 1' of the described type, joined firmly by means of the interposition of an upright 6, which is projecting from a panel edge, and of an upright 7, which is receding from the other edge. In this way a double layer suitably spaced box-shaped panel is achieved, with a projection at one edge and with a rectangular section hollow recess at the o her edge, in which the projecting portion of the adjacent panel could be fixedly joined. The fixing of the spacing uprights 6 and 7 to the panels 1 and 1' of each module is always carried out in correspondence of the folded portions 3 and 3' , that have suitable sturdiness, by virtue of the double thickness.

The retardant fire fixed joint walls are particularly cheap to make temporary fittings, for instance in the exhibition, since the elements could be easily recovered after the use, unlike it is allowed by the known plasterboard panels. For these installations in which it is necessary the observance of the fire safety rules, metal uprights are used instead of those of wood.

Support 8, illustrated in the figures 7 and 8, could be inserted to facilitate the carrying out of false ceilings, in correspondence of the folded side portions of each panel. Each of these supports has a hole for hooking the connecting rods 9, hanging down from the ceiling 10 shown in figure 7. The false ceiling is made alternating the strengthened panels 1 with ordinary panels 11, that are supported by these first and are accordingly in staggered position. The possible irregular edges of the panels 11, do not present aesthetical problems since they are not visible. Likewise panels 1 with strengthened edges exclusively, could be used simply placing them side by side and on the same plane.

A second embodiment of the panel in object could be achieved arranging the folded portions 3 opportunely spaced from the inner surface of the panel 1 (by previously suitably spacing the two millings of each couple) , so as to leave a recess inside the edge, for the insertion of a wooden listel 12, as shown in the figures 9, 10 and 11. In this case the achieved panel has higher strength both for the increased thickness of the side portions 3, and for the insertion therein of a reinforcement

element constituted by the wooden listel 12. This latter could project inwardly from the folded portion.

Wall units or other heavy articles could be directly hanged on the walls carried out with this kind of panels, with the only attention of inserting the screws in correspondence of the strengthen portions easily determinable by virtue of the absence of puttying. The panels 1 of this second embodiment could be advantageously used to make false ceilings, because of the possibility of applying supports, listels or other accessory elements thereto simply by means of screws . Instead of the wooden strengthening listel it is possible to use another material, for instance the same plasterboard if it is desired to preserve the retardant fire features of the panels 1.

Obviously the unessential constructive details could be different from those illustrated only by way of example, without going out from the protective field of the present invention.