The invention refers to wind towers integrated in a set, each of them constituted by a metallic structure which develops in the vertical way and which supports a series of wind turbines of vertical axis, disposed by a successive overlapping, having got the same rotation shaft and the same hydrostatic unit of strength transmission. The said hydrostatic units in each set are interconnected by a hydrostatic connection system to a hydrostatic engine and a safety system is applied to each shovel of the turbines.

2. Description of the related art.

The technique of the turbines of vertical axis has not been developed due to the difficulties which are imputed to them such as the low rotation speed and the lack of safety as far as strong winds are concerned.

Thus, it has only been paid attention to the development of turbines of horizontal axis, though they have got a very low efficiency in catching the wind energy and their functioning needs a high space occupation, which must take into account not only the shovels diameter and their"translation-orientation" movement but also the distance between each turbine, so that the resonance generated by the vibration of the shovels themselves may be reduced.

OBJECTIVES AND EXPLANATION OF THE INVENTION a) Reduction of the space occupied by the turbines of vertical axis to less than, 5 per cent of the space occupied by the turbines of horizontal axis with the same power. This aim is achieved by: - the overlapping of several turbines of vertical axis forming a"wind tower", Figure 1; - a greater proximity between the wind towers, because the turbines of vertical axes do not produce vibrations as the material of the shovels plugs is of a textile nature; - the frontal exposure and the much bigger relative area of exposure of the shovels thus being obtained a much higher efficiency in the catching of the wind energy. b) Reduction of the construction costs: - in a turbine of vertical axis, the construction of the shovels structure is obtained by the connection of simple and modulated straightened elements which have got a low performing cost; - in a wind tower the support structure is lighter proportionally because it has got a much bigger area of attachment to the ground and it supports several turbines so as to have the same rotation axis and the same unit of strength transmission; - in a turbine of horizontal axis the shovels have got an accurate and balanced form which has a high performing cost and the support structure is more concentrated, which requires a high resistance, thus resulting a bigger relative weight. c) Application of a safety system: - in the turbines of vertical axis it is applied a safety system which regulates and limits the speed of its rotation, performing the progressive winding of the plugs according to the increase in the wind speed, Figures 3,4 and 5 ; d) Application of a hydrostatic connection system of strength transmission: - a hydrostatic circuit connects the hydrostatic units of strength transmission of, for example, a set with four wind towers, each of them with four turbines, to one only hydrostatic engine which drives an electrical generator. This advantage allows the reduction, in this example, of the number of generators from 16 to 1, the obtaining of a higher efficiency in the transformation of the caught energy, and an easier control of the electronic circuits of steering of the system of energy production, Figure 2.

INVENTION SUMMARY Each wind tower integrated in a set is a metallic structure constituted by four vertical columns, connected by modulated elements (Z) which centralise several wind turbines of vertical axis ; the said turbines have got a common rotation shaft (, which drives a hydrostatic pump (HP), Figure 1.

The turbines preferably have four shovels, each shovel is constituted by two metallic window frames which support a plug (V), symmetrically connected to a shaft (Y), Figure 4, whose rotation is synchronised with the rotation of the said common rotation shaft (X).

A safety system, applied in each shovel, and including the devices (PI), (M1) and (P2), (M2), regulates the turbines rotation speed, performing the progressive coiling of the plugs according to the increase in the wind speed and its pressure on the plugs, Figures 3,4, 5 and 6.

A system of strength transmission is obtained by a hydrostatic circuit (HL), which connects the said hydrostatic pumps (HP) to a hydrostatic engine (MP), which drives an electrical generator (G), Figure 2.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows the structure of a wind tower which includes, for example, four turbines of vertical axis, each of them having four shovels, and one of the shovels is seen in the frontal position (I) ; support columns (S), connection

elements (Z), the common rotation shaft N and the respective unit of strength transmission (HP).

Figure 2 shows a scheme of the hydrostatic connection system of strength transmission of a set of wind towers, in which a hydrostatic circuit (HL) connects the said pumps (HP) to a hydrostatic engine (HM) which drives an electrical generator (G).

Figure 3 shows a partial scheme of the functioning of the safety system in order to obtain the progressive coiling (E) of the plugs (V) in correspondence with the increase in the wind speed and pressure (p).

Figure 4 is a frontal view of a shovel and it shows a temporising device (Ml) and (PI), connected with the upper terminal of the support (C) for the plug traction, and the device (M2) and (P2), connected with the support (E), for the plug coiling.

Figure 5 shows the functioning of the said devices.

Figure 6 shows an"ultra-fast"disconnecting device of the support (C) to the connection wires of the rods of the said temporising devices.

Figure 7 is a bigger scale view of a piston valve (PI) and (P2).

DESCRIPTION OF THE PREFERRED EMBODIMENT Each wind tower (Figure 1), integrated in a set, is a metallic structure which develops in the vertical way, being constituted preferably by four columns (S), attached to the ground in an extensive way and connected by modulated elements (Z) which centralise the rotation shaft, common to several turbines of vertical axis (1), disposed by a successive overlapping; the said rotation shaft N drives the same unit of strength transmission, constituted by a hydrostatic pump (HP), positioned at a near the ground level.

The wind turbines have a got four shovels preferably, each shovel is constituted by two metallic windows frames symmetrically connected with a shaft (Y) whose rotation is synchronised with the rotation of the said rotation shaft %) ouf the wind tower.

Each window frame supports a plug (V) constituted by a textile web, attached to the cylindrical support (E) and to support (C). Support (E) can coil the said plug and support (C) can move supported in troughs, stuck on the upper and lower sides of the window frames, so as to allow the said plug coiling, Figure 4.

To each plug (V) it is applied a safety system, whose aim is to obtain the regulation of the rotation speed of the turbine so as not to exceed the speed level which was previously established for the said turbine rotation, and so as to obtain the good use of the winds with an excessive speed.

The said speed regulation consists of the reduction of the radial extension of the plug exposed to the wind, in proportion with the increase in the wind speed and pressure.

Each safety system includes two devices (PI) and (M : 1), which respectively act on the support extremities (C) and a device (P2) and (M2), which acts on support (E), Figure 4.

Each device is constituted by a hydrostatic cylinder and a piston (PI) and (P2) ; the said piston functions as a valve and it is connected with a rod (1), which acts according to the traction strength of the respective springs (M !) and (M2), Figure 5.

In order to obtained the functioning of the said safety system, the traction strengths of the springs (Ml) are applied in the support extremities of the plug attachment (C) by means of differential pinion (D) in which the pinion with the widest diameter coils the wire connected with support (C) and the pinion with the narrowest diameter coils the wire connected with rod O. The differential pinions allow that the course of the pistons-valves and also the length of the hydrostatic cylinders are shortened.

The said traction strengths of the springs (M1) balance the traction strengths produced in the said plug by the wind pressure (p), blowing at the safety speed established for the turbine rotation, when the plug is in the frontal position to the wind direction, Figure 3. When the wind speed, established as a safety level, is exceeded, the pressure (p) on the plug increases and gives origin to a bigger traction strength of the plug itself on the support (C). As the said strength is bigger than the springs strength (M1) it forces these ones to their compression and to the displacement of the piston-valve (PI) and the rod T in the opening direction T1 of the valve aperture, Figure 5 The increase in the springs (Ml) compression, the plug (V) sinking and the support (C) retraction are in correspondence with the increase in the pressure on the plug ; the said increase results from the excess of the speed wind.

In the next"step"of the turbine rotation, the shovel turns from the frontal position to the wind direction to a parallel position to the said wind direction, Fig. 3. In this position the wind pressure is null, as well as the corresponding traction strength of the plug. The return (R1) of the springs (M !) is prevented trough the locking of the corresponding valve (PI). At the same time, springs (M2) of the coiling devices are free from the contrary traction strength of the springs (M1) and perform the traction (T2) movement from which derives the coiling (E) of the plug in the extension corresponding to the sinking, and retraction of the plug in the previous position, Figure 5.

By continuing the increase in the speed wind and therefore the increase in its pressure on the plug, the"step"that was described repeats itself for each turbine rotation, being obtained a constant balance between the increase in the wind speed and the reduction of the exposure extension of the plug.

By returning the wind speed to the speed considered as of safety, the traction strength of the springs (M !), being bigger than the traction strength of the springs (M2), performs the progressive coiling of the plug according to fluid drainage in the devices; the said drainage is regulated by means of orifices of gauge appropriate inserted in the pistons (PI) and (P2).

An instantaneous disconnection device, constituted by a peg with a triangular shape, bordered and pressed by a laminar spring, Figure 6, is interposed in the support connections of the plug (C) with the devices (P2) and (M1), Figure 4 ; the instantaneous disconnection of the said devices, in consequently of the sudden charges of the wind speeds deriving from cyclones, typhoons, allows the instantaneous coiling of the plugs performed by device (P2) and (M2).

A wind tower concentrates the strength obtained by several turbines in the same unit of strength transmission, constituted by a hydrostatic pump (HP).

The connection of the wind towers integrated in each set is obtained by the application of a hydrostatic connection system of the strength transmission.

The said system is constituted by a hydrostatic circuit (HL), which connects the hydrostatic. pumps (HP) of the wind towers of each set to one only hydrostatic which drives an electrical generator (6), Figure 2.

The application of the said system substantially reduces the number of generators, it obtains a higher efficiency in the transformation of the energy caught into electrical energy and it performs an easier control of the electrical energy and performs an easier control of the electronic circuits of steering.