Once the values of Fg and Fp satisfying the equilibrium condition defined in the previous equation are fixed, let us hypothise that our machine has undergone a small α angle rotation on the vertical plane In this case (fig. 8)

M(O) = - (d cos α - e sen α) . F_g + 1 cos α . F_p ; Dividing for cos α we'll have:

M(O)/cos α = - d . F_g + 1 . F_p + e tan α as for [ 2 ]: - d . F_g + l . F_p = O

we have:

M(O)/cos α = + e tan α for 0° < α < 90° we have: cos α >0 tan α>0; so:

M(O)>0

In other words, a couple tending to rotate the structure in hour sense acts to the structure up to carry it into the perfectly horizontal position; this couple is as more important as the floating center has been placed away from the principal axis. The machine would have the same stabilizing behaviour also in the hypothesis of the initial rotation in the negative sense. In presence of stream

In case the machine is immerse in the stationary water stream (v. fig. 9) it is necessary to consider also the horyzontal force S₅ equal to the resultant of the two pushing forces to the helixes summed to the friction force of the frame on the water. Considering that the first two pushing forces (those to the helixes) are absolutely preponderant in relation to structure friction the resultant S is approximately applied to the O-C axis.

In equilibrium conditions (horyzontal position) the resultant S provokes a zero moment in relation to O point. Consequently, the horizontal pushing force value does not influence absolutely on the machine equilibrium.

Differently, such a pushing force becomes important for determining the backspring cabe direction. In fact, for the forces and acting moments equilibrium the backspring

cable must be directed in relation to the θ angle; moreover, the traction T acts on the

same cable.

Also in presence of stream, we consider that the machine ungoes a small rotation by α angle (fig. 10).

In such a hypothesis the S force moment in relation of O point is not equal to zero. Still, it is certainly positive and furtherly balancing.

In other words, the stream contributes, as it was intuitively obvious, to maintain the machine in a horizontal position.

The invention, certainly, is not limited, to the representation of the figures, but can receive perfections and modifications from men skilled in the art, without going out of the patent frames.

Present invention permits numerous advantages and, particularly, allows to overcome the difficulties that could not be superated using the systems that are actually in commerce.

Claims

1. Electrical generator driven by the sea stream constituted by a frame carrying on its ends two blade counter-rotating helixes having three o more dovetailed blades with two alternators, almost cylindrical floater, anchorage block, sufficiently heavy to hold the frame and a floater when immersed and subject to the maximum intensity of sea stream, fixed on sea floor, backspring having one wrapped cape placed in the frame and another fixed to the anchorage block, an electrical cable for connecting the alternators to the electrical network, characterised by the fact that the frame is the reticular frame on which two maneuver means are placed for electrical generator alignment with the sea streams.

2. Electrical generator driven by the sea streams as to the claim 1 characterised by the fact that maneuver means are two rudders.

3. Electrical generator driven by the sea streams as to the claim 1 characterised by the fact that maneuver means are two maneuver helixes.

4. Electrical generator driven by the sea streams as to the claim 1 characterised by the fact that networking structure is formed by circular, square o other form section bars.

5. Electrical generator driven by the sea streams as to the claim 1 characterised by the fact that the structure is a folded-plate frame composed by press curved plates having a form that permits to convey the stream towards the two helixes and regulate the stream effectively.

6. Electrical generator driven by the sea streams as to the claim 1 characterised by the fact that the floater is composed by one or more cylindrical hulls or of a form such that permits to convey the stream towards the two helixes and regulate the stream effectively.

7. Electrical generator driven by the sea streams as to the claim 1 characterised by the fact that the anchorage block is composed by different parts that run one into another and are assembled by a simple contact one with another in the unique block.