More in particular,. this invention refers to a procedure for obtaining tiles or panels which have a structure that allows them to be used to construct raised floors or covering.

This procedure is used for the production on an industrial scale of panels or sheets made from conglomerate material, in particular a material generally consisting of cement, marble and/or quartz and/or sand and/or granite-based mixtures, also comprising possible intrusions of various kinds, such as metal elements, glass, wood, etc.

This invention also refers to a die which can be used on a machine to obtain cement tiles or panels, equipped with several stations for carrying out a complete and. automatic work cycle.

Finally, the invention refers to-a cement tile or panel advantageously obtained according to this procedure and with this die.

The invention applies mainly to the industrial processing field of. marble, stone, granite and the like.

BACKGROUND ART This applicant has already proposed a procedure for the production on an industrial scale of cement tiles or

panels or sheets, see international patent No.

PCT/-IT01/00636.

This procedure comprises the following processing stages: - crushing of the inert stone material; - preparation of a mixture consisting of water, crushed material and inert cement sand binders; - preparation, in a pressing die, of a plastic frame inside which a wire-mesh reinforcement is positioned; - batching of this mixture inside the die; pressing of the mixture in order to obtain a tile presenting a predetermined configuration and predetermined dimensions, this pressing being carried out by means of a punch-holder shaped block, positioned in operation above the die, designed to support, a plurality of punches which penetrate the mixture between the links of the wire-mesh; - extraction of the tile from the press and subsequent curing of the tile.

A procedure such as the one described above makes it possible to obtain cement-tiles or panels with precisely predetermined lengths, widths and thicknesses, and is performed in a continuous process on a specially designed plant.

One disadvantage of this procedure is the need to foresee the presence of a synthetic or metal frame to support the wire-mesh reinforcement, thus making the procedure more complex and the costs of each tile or panel higher.

DESCRIPTION OF THE INVENTION This invention proposes to overcome the drawbacks present in the background art. Improvements to the basic procedure described above have therefore been made, and in particular it has been made possible to eliminate the wire-mesh support frame. This makes the procedure more rapid and more simple, and the resulting tile more economical.

To achieve these aims, a dispenser is used between the mixing phase and the pressing and compacting phase, designed to pour predetermined quantities of crushed material into an appropriate die in order to give it a predetermined configuration, for example square, rectangular or in any case polygonal.

With the procedure carried out thanks to the features described in claim 1, tiles are obtained that are inert from a mechanical and electrical point of view, being free of resinous material and using only cement as a binder.

In this way the tiles are completely fire-proof and can therefore be classified as"class zero".

From the above description it can be deduced that these cement tiles are, particularly suitable for floating or raised floors, which generally present a reticular frame designed to support panels above the ground in order to construct-a hollow space designed to house electrical and/or hydraulic ducts.

According to another aspect, this invention proposes to provide a die which can be used in cooperation with a machine to produce cement tiles or panels according to this procedure.

This die is described in claim 4.

According to another aspect, this invention proposes to provide a cement tile or panel with a relatively limited thickness and at the same time good mechanical resistance so as to offer a high degree of flexibility during laying, thereby limiting risks of cracking.

This tile or panel is the subject of claim 7.

The dependent claims describe advantageous embodiments of the invention.

The procedure for the production of cement tiles or panels according to this invention foresees: - crushing of the various materials making up the conglomerate; preparation of a mixture consisting of water, crushed material and inert cement sand binders; - a first batching of the mixture inside a pressing die until a part of the die is filled ; - positioning, on top of the material poured into the die, of a wire-mesh reinforcement; a second batching of the mixture, into the die, to cover the wire-mesh reinforcement; - pressing of the mixture in order to obtain a tile with a predetermined shape and predetermined dimensions; - extraction of the tile and its subsequent curing.

According to a particularly. advantageous embodiment of this invention, immediately after the pressing die has been filled the cement material is subjected to vibration compression in order to-make it more homogeneous and well distributed inside the die.

The pressing is achieved by means of a shaped block, positioned in operation above the die, designed to support a. plurality of punches which penetrate the mixture through the links in the wire mesh.

According to the invention, the die for the production of tiles is part of a plant already known and used in this particular sector; as such, the die is shaped with sloping walls. In this way, the tile produced in the die will also have side walls which slope inwards at a predetermined angle from the visible surface of the tile.

Tiles or panels are thus obtained which are extremely easy to lay, reducing the thickness of the joints and avoiding the risk of breakage during laying.

DESCRIPTION OF THE DRAWINGS Other features and advantages of the invention will become evident on reading the following description of one ~form of embodiment of the invention, given as a non- binding example, with the help of the enclosed drawings, in which: figure 1 shows a perspective view, slightly from above, of a tile according to the invention; figure 2 shows a plan view from below of the tile according to figure 1 ; figure 3 is a front elevation of the tile according to the invention, in which some internal details of the tile are shown.

DESCRIPTION OF ONE FORM OF EMBODIMENT The procedure according to this invention is carried out by using an automated control machine already known in the sector, controlled by a specific electronic. unit which manages the entire-production cycle of the tiles or panels.

The tile or panel 10 according to the invention is made from inert conglomerate material with an internal wire-mesh reinforcement 12, its base surface 15, not visible when laid, presenting a plurality of cavities 17 corresponding to the links of the wire mesh.

The cavities 17, which can present a depth corresponding to a good part of the thickness of the tile, ensure a considerable reduction in weight of the panel or tile 10 without jeopardising the. features of mechanical resistance ensured by the presence of the metal

reinforcement.

The procedure for obtaining tiles or panels 10 according to the invention foresees: - crushing of inert stone material; - preparation of a mixture consisting of water, crushed material and inert binder cement sand; - batching of a first predetermined quantity of this mixture inside a pressing die (not shown in the figures) ; - positioning, inside the pressing die, above the first predetermined quantity of the mixture, of a wire-mesh reinforcement 12; batching of a second predetermined quantity of the mixture inside a pressing-die ; pressing of the mixture in order to obtain a tile 10 with a predetermined shape and predetermined dimensions, this pressing being achieved by means of a shaped block, positioned above the die, designed to support a plurality of punches which penetrate the links of the wire mesh 12; extraction of'the tile 10 from the press and subsequent curing of the tile.

According to a particularly advantageous form of embodiment-of the invention, the shape of the pressing die. is such that the tile formed inside it has side walls 11 (see fig. 3) which slope slightly inwards, for example at an angle between 2° and 8°, starting from the visible surface 13, when laid, of the tile 10.

The tile or panel 12 obtained by means of the procedure described above, consequently has a substantially truncated pyramid shape.

The shape of the die with slightly sloping walls thus makes it possible to obtain tiles which are extremely easy

to lay, particularly in the case of laying raised floors (floating floors).

According to an favourable form of embodiment the invention, during the compression of the material it is simultaneously subjected to vibration, in order to distribute it homogeneously inside the die.

Once the procedure has been completed, and the tile 10 has been extracted from the die, it is then transferred, by means of a conveyor for example, to other machine tools in order to carry out the usual finishing processes, for example polishing.

The machine can be equipped with sensors and/or transducers connected to an electronic control unit- designed to manage the production cycle on a continuous basis.

By means of the procedure described above, it is possible to produce tiles 10 with a square shape and a. visible surface 13 with sides that are 60 centimetres in length.

Pressing can be achieved by means of a shaped block, positioned in operation above the die, designed to support a plurality of punches which penetrate the mixture between the links of the wire mesh 12 to form the cavities 17.

The pressing pressure can be 240 bars.

Thanks to its sloping side walls 11, the tile 10 can easily be laid to construct any type of floating or raised floor.

The"zero class", ensured by the presence of cement binders, certifies total electrical insulation and perfect fireproof properties.

The procedure described above also makes it possible to avoid the use of support frames for the wire mesh 12, thus reducing the general manufacturing costs.

The invention is described above with reference to a preferred form of embodiment. It is nevertheless clear that the invention is susceptible to numerous variations, within the framework of technical equivalents.