The present invention relates to a particular kind of wire comprising an outer mantle realized in metallic material and an inner portion in fiber, to be used autonomously or for the creation of strands or ropes, characterized by advantageous mass- resistance ratio.

At the state of the art, there are currently known different kinds of wire, or strands and ropes deriving therefrom, which are wholly realized in steel or other metallic material, and having undoubted advantages, such for example:

- high axial resistance;

- high capacity to bear transversal forces;

- high capacity to resist to wear phenomena;

- high corrosion resistance.

Said devices have significant drawbacks as well, such for example:

- little resistance to fire or, more generally, to high temperatures exposure, thus compromising sensibly the resistance of the metallic portions;

- high material specific weight, which inevitably leads to the overall high weight of the products realized therewith. Just this latter aspect implies the most critical disadvantages · of the known devices: in fact, in particular when vertical extended structures are referred (as for example cableways, offshore cranes, drift mines and the like) , and moreover in case of very high and large structures, it is inevitable to take in consideration the weight of the single members used to bear loads.

Also in case the devices are intended for the use in water, in which case they get a hydrostatic push which leads to their overall weight to be lightened in the order of 13%, the aspect linked to the specific weight of the materials is yet significant; it is in fact clear that the effect of weight reduction of the weight linked to the floatation push is, in percentage, as greater as the specific weight of the used materials is lower. A possible solution for re-dimensioning the problems linked to the high specific weight of the construction materials lies in the possibility to use materials other than metals, as for example fibers: a constructive choice of this kind leads to the realization of a wire with highly developed mechanical features, thus guaranteeing a drastic reduction of the final product weight. But the realization of ropes and strands entirely deriving from- fiber is not possible; in fact even if the highly developed mechanical features of said materials are certain, there are as well critical points which prevent the fiber strands from being used as sole constructive material in the realization of wires, strands and ropes, such as for example:

- problems linked to the rapid wear;

- little resistance to axial stresses;

- higher exposure to damages with respect to the metal materials;

- little detection of possible damages.

Aim of the present invention is to provide a solution which is able to overcome the main problems of specific weight, efficiency and heat resistance, peculiar to the state of the art, by means of a device which can optimize the ratio between mass and resistance thus preserving the inner fiber performance.

Another aim of the present invention is to provide a device which can be used differently in relation to the material kind in the constructive phase and in relation to the kind of treatment received.

The aim is solved by means of a new kind of composite wire, characterized by an outer mantle in metallic material and an inner portion comprising fibers and/or · pultruded bars, able to conjugate the constructive advantages deriving from the use of these latter, and avoiding as well the problems in terms of wear exposure and damages by means of a protective coating mantle.

These and other characteristics of the invention will be better highlighted in the following description of a preferred embodiment, which refers to the drawings 1/3, 2/3 and 3/3, in which:

figure 1 shows the section of a preferred embodiment of a strand made up of wires characterized by an outer mantle in metallic material and an inner portion in fibers;

figure 2 shows the section of a preferred embodiment of a strand made up of wires characterized by an outer mantle in metallic material, a first inner layer of fibers and a second inner layer represented by a pultruded bar, the whole being after subjected to a compacting process ;

figure 3 shows the section of a preferred embodiment of a rope, made up of strands in turn realized by means of wires characterized by an outer mantle in metallic material and an inner portion in fibers; figure 4 shows a tridimensional view of a preferred embodiment of a wire, characterized by a linear outer mantle in metallic material and an inner portion in fibers in parallel bundles;

figure 5 shows a tridimensional view of a preferred embodiment of a wire, characterized by a linear outer mantle in metallic material, a first inner layer in fibers arranged in parallel bundles and a second inner layer represented by a pultruded bar;

figure 6 shows a tridimensional view of a preferred embodiment of a wire, characterized by an outer mantle in linear metallic material and an inner portion in helical fibers;

figure 7 shows a tridimensional view of a preferred embodiment of a wire, characterized by a helical outer mantle in metallic material and an inner portion in fibers in parallel bundles.

As yet stated, object of the present invention is a particular and innovative kind of composite wire 10, having an outer mantle 1 in metallic material with protective functions, and an inner portion in fibers 2, able to overcome the problems linked to the specific weight and little resistance to high temperatures and pressures at the state of the art, and characterized by an advantageous mass- resistance ratio.

By using an outer mantle 1 realized in metallic material it is possible to solve the damaging and little resistance to transversal load problems, peculiar to the fibers 2.

Likewise, the introduction of an inner portion comprising fibers 2 and/or pultruded bars 3 makes it possible to obtain sensible advantages, as for example :

- sensible reduction in the specific weight of the construction material (for example in a possible preferred embodiment of a wire 10, which is 40% made up of steel and in the remaining 60% made up of highly resistant fibers with specific weight approximately 1,4, there results a final device with a specific weight equal to 50% of the steel one, in the air, or 40% in water) ;

- higher fire resistance;

- higher resistance in case of high temperatures, above all in the case the composite wires 10 containing an inner core in glass fiber 3;

possibility to delay the inner temperature increase of the wire 10 in case of prolonged exposure to high temperatures;

- contribution to the whole load capacity. Figures 4 to ^■ 7 represent tridimensional views of preferred embodiments of the invention, some of them being made up of only two layers, i.e. a linear (figures 4 and 6) or helical (figure 7) outer mantle 1 in metallic material, and an inner portion in fibers 2 arranged in parallel bundles (figures 4 and 7) or helically (figure 6), the other one comprising also another inner portion represented by a pultruded bar 3 (figure 5) . The use of a bar in glass fiber 3 as innermost layer of the wire 10 (figures 2 and 5) contributes sensibly to implement its features of resistance and of high temperatures and transversal pressures bearing.

Clearly, the axial and transversal, dimensional and resistance features as well as the elasticity of the wire 10 can be differently modulated using metal containing tubes 1 with different resistance, diameter or thickness, possibly helically wound as well, in turn in variable combination with different combinations of fibers 2 and/or pultruded bars 3, which can be used in parallel or helical bundles (figures 4 to 7) as well.

Also the external features of corrosion resistance of the wire 10 can be differently determined by choosing materials for the realization of the outer mantle 1, as well as the respective superficial finishing with or without the edges to be welded; in this last case, considering all the other features for certain, an increase of the torsional resistance of the wire 10 can be detected.

Finally, also the different mode of treatment and impregnation (resins, lubricants, buffers) of the fibers 2 contributes to different connotations of the used material.

As yet stated, said composite wires 10 can be used autonomously, as long as they are provided with specific ends or connections, or they can constitute portions of the bundles, strands 12

(figure 1), these ones also being compacted (figure 2), or of ropes 13 made up of said strands 12

(figure 3) .

With these features in terms of lightness and resistance, peculiar to the device object of the invention, it is clear that this one is mainly intended for the use in all the fields where the aspect linked to the specific weight of the various elements is particularly important (offshore deep sea, drift mines, aeronautics, architecture) : said uses represent however a purely preferred possibility of use and do not exclude other possible and suitable uses. In particular, it is to be highlighted that said wire can be -also used as vehicle for conducting electric energy, using the composite strands 2 coated with an aluminum mantle 3: such a possibility would allow to solve many problems linked to the weight and the high thermal expansion of the solutions currently available, which are mainly characterized by the use of steel and aluminum cables.

What described represents only some preferred embodiments of the invention; it is intended that modifications and/or variations of the same are possible, without departing from the aims of the present invention, as defined by the following claims .