It is known that the systems used until now on ships and boats for facilitating the lateral movements during manoeuvres in small spaces or with side winds, are essentially based on manoeuvre propellers installed in fitting housings arranged below the floating.

Moreover, said systems are a great risk for what concerns safety due to the presence of great openings below the floating line, and a limit for the maintenance and for the hydrodynamic advancement; furthermore, they have the disadvantage of requesting expensive fitting onto the hulls that use them, like e.g. the insertion ahead of passing-through tubular structures of great diameter that may contain transversal propellers.

Furthermore, on some boats - like sailing boats or some motor-boats - which have small head wheels, such systems can not be applied.

It is the aim of the present invention to make easy the manoeuvres of ships and boats of all kinds, making use of a system based on the principle of action and reaction, determined by a jet of a fluid generated by pumps housed in the hull and that comes out under pressure from suitable nozzles, possibly internally shaped like a Venturi pipe or similar so as to obtain, in the outlet points of the fluid and due to fitting throttlings, a direct force in opposed sense and proportional to the pressure and to the volume of pumped fluid.

Consequently, the present invention provides the presence of nozzles on opposed bulwarks at the end of the stem that will determine, following to the outlet of the fluid under pressure above the sea level, the displacement for reaction from the head of the boat and therefore the possibility of immediately performing right or left curves, according to the employed nozzle.

In a similar way, rotations around the barycentre will be allowed with the help of corresponding nozzles arranged on opposed bulwarks near the stem; the hydraulic reaction operation of the two nozzles arranged on the same bulwark will determine the parallel motion of the whole craft for coming along- side to quays or for performing another manoeuvre.

The advantages of the system according to the present invention are evident.

The system according to the present invention will be described more in detail hereinbelow relating to the enclosed drawings, in which an embodiment is shown.

Figure 1 shows a scheme of a hydraulic system for the control of boats, ships and crafts in general, installed onto a boat.

Figure 2 shows a lateral view of a possible localization of the nozzles on a boat.

Figure 3 shows in detail the internal structure of a ejector nozzle.

In figure 4, the arrows show possible manoeuvres of hulls provided with the system according to the present invention.

Figures 5 and 6 show, in a respetive axonometric view and transversal section, a variant of ejector nozzle with internal throttling.

Figures 7 and 8 show a scheme of two variants of pressing or pulling ejector nozzles, which are particularly fitting on boats used for trawling.

The enclosed figures show a hydraulic system for the control of boats, ships and crafts in general, comprising: - two or more front nozzles 1, 2 and/or two or more back nozzles 3,4, with dimensions proportioned to those of the boat N and to the capacity of the pumps 5 housed in the hull and fixed to the bulwarks in determined points by means of passing-through holes and operated under control by means of valves 6 operated with mechanical, hydraulic, electric systems or engines or of other kind; - one or more pumps 5 housed in the hull N, operated by the engine of the boar by means of electro- magnetic pulleys, by means of hydraulic or electric transmissions or of other kind, or by an autonomous motor energy source of any kind, for supplying the thrust to the fluid under pressure, that may be water directly collected from the bottom through intake 7; - an internal structure of said nozzles 1, 2, 3, 4, operated by electrovalves 6 and having the shape of a throttling 8 of a Venturi pipe, for increasing and adjusting the hydraulic thrust; - a control board 9 arranged on the bridge, for the localization of the electric switches or of the operating controls.

The functioning of the hydraulic system for the control of boats, ships and crafts in general, according to the present invention, may be described as follows: - the engine of boat N operates a pump 5 by means of pulleys with electromagnetic clutch; - said pump sucks water from the bottom of said boat N, by means of an intake 7 from the sea; - the water is pushed through pipes to nozzles 1,2,3,4 choses for the manoeuvre, arranged on the bulwards and operated by electrovalves 6; - when the electric switches provided on the bridhe are operated, electric feeding is supplied to the pulley, that starts the pump, at the same time to the electrovales chosen for supplying the thrust in the desired points.

In a variant of the hydraulic system according to the present invention, the system provides the presence of one or more nozzles arranged backwards or frontwards to the boat or ship or craft, so as to ex- ploit the thrust of the pumps, also in case of breakdown of the main engines or of the other moving means, so as to obtain an emergency movement, particularly efficient in sailing-boats or for pulling, al a low speed, fishing boats.

In the variant shown in figures 5, 6, the ejector nozzle consists of a plurality of elements asembled by means of screws 11: - a cylindric body externally threaded, with the end section reduced by the internal flange with central hole 17; - an external counterflange fastened to said body 1 3 by means of said screws 11 and with the interposition of a sealing gasket 19, and shaped in one single piece with a metal ring 1 2 with different inclinations that may be fitted to the different shapes of the bulwarks, and with an internal flange 1 8 in specular coupling with said internal flange 10 with a central hole 20 of a diameter slightly greater than the one of said central hole 17, so as not to hinder the outflow of the liquid jet that is accelerated and which, due to the principle of action and reaction, determines a considerable direct thrust in the opposite sense, proportional to the liquid quantity pumped; - a spacer 1 6 that brings back the plane to be normal to the cylinder through the washer 1 5 and the nut 14.

The installation of above mentioned nozzle may be described as follows: - a passing-through hole having the same diameter of the external diameter of the cylindric body 13, in performed in the bulwark; - a metal ring 1 2 is chosen; having an inclination corresponding to the one of the bulwark; - the nozzle at the bulwark is blocked by tightening the nut 14; - the nozzle is connected to the hydraulic circuit, making use of the remaining threaded part of the cylindric body 1 3.

For mounting in small spaces the latter nozzle described, it appears to be possible to separate the body 1 3 from the flange 1 8 by unscrewing screws 11, and previously connecting said body 1 3 to the hydraulic circuit and then proceeding with the coupling of the parts through the passing-through hole performed in the bulwark, screwing again the screws 11 and tightening the nut 14, that previsously had been left loose.

The variants of the system according to the present invention shown in figures 7 and 8 are particularly fitting for solving the problem of the slow motion, at different speeds, of boats and crafts used for trawling, wherein traction under action and reaction may be applied also to the stem of said crafts.

In the variant according to figure 7, the body of the ejector 1 3 consists of a curved tubular whose external ed is internally reduced by said flange 10, and shows at the other end a threading 21, or even a rubber supporting edge 22 for the connection to the hydraulic system, while said ejector forms a single body with external flange 1 2 with many inclinations due to its perfect fitting to the external curving of the bulwark to which it is applied by means of screws 11, so that the fluid, pushed by the pump, due to the presence of said flange 10, flows out under a considerable pressure and with a direction nearly parallel to the bulwark of the boat, causing its frontward moving, if it turned towards stern, or backward, if it s turned towards stem.

The same function may be fulfilled, according to the present invention, by the variant shown in enclosed figure 8, consisting of a telescopic forward nozzle, formed by a pipe 23 of different length and the outer end thereof has a curve 24 turned in the opposite sense and provided, in the fluid outlet point, with a flange 10 while, at the inner part of said tube the seats for housing two o-ring sealing gaskets 30 are performed, so that the nozzle is free to slide inside a pipe 29, fastened to the hull, and provided, an the inner end, a perforated cap 25 with a sealing gasket 26 onto the body 23 of the nozzle, while on the opposite side a perforated and threaded cap 27 allows the connection to the hydraulic system.

Furthermore, at the end of said tube and nearby the outer sealing, a threaded hole 28 is performed for fastening, by means of nipples, a small pressure pipe.

When the fluid under pressure gets in through said cap 27, said nozzle 23 is first thrust by said fluid until it stops onto cap 25, with following outflow of said nozzle from its forward housing in the hull, and then it can perfor, due to the outlet of the fluid under pressure, through flange 10, the reaction effect with the consequent traction of the boat.

When the nozzle has acomplished its task, it get ins again into pipe 29, due to the intake of fluid under pressure through the threaded hole 28.