Abstract:
A hydraulic system for the control of boats, ships and crafts in general that comproses nozzles (1, 2) opposed and the end of the stem, having a Venturi tube throttling (8) or an internal diameter reduced by means of flanges (10), so as to be able to determine, following to the outlet of the fluid under pressure, the movement by reaction of the front part of the boat (N) and therefore to perform immediate leftward or rightward curvings according to the nozzle used, and/or corresponding nozzles (3, 4), placed nearby the stern and with similar background function, while the operating the hydraulic reaction of both nozzles placed on the same side determines the parallel movement on the whole craft, for moming alongside to quays or for performing other maneuvers.

Description:
FIELD OF THE INVENTION 
     The present invention concerns a hydraulic system for the control of boats, ships and crafts in general, working on the principle of action and reaction. 
     BACKGROUND OF THE INVENTION 
     It is known that the systems used until now on ships and boats for facilitating lateral movements during maneuvers in small spaces or with side winds, are essentially based on maneuver propellers installer in fitting housings arranged below the vessel floating line. 
     Moreover, said systems are a great safety concern due to the presence of large openings below the floating line that complicate maintenance and hydrodynamic advancement; furthermore, past systems have the disadvantage of requiring expensive fitting onto the hulls of ships that use them, for e.g., the insertion of pass-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 maneuvers 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. The nozzles may be internally shaped like a venturi pipe or similar shape so as to obtain, in the outlet points of the fluid and due to fitting throttlings, a direct force in the opposite direction of the discharged fluid 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, due to the discharge of the fluid under pressure above the sea level, the reactive displacement of the head of the boat and therefore the possibility of immediately performing right or left turns, 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 entire craft for maneuvering along a warf or for performing a different maneuver. 
     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. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows a scheme of a hydraulic system for the control of boats, ships and crafts in general, installed onto a boat. 
     FIG. 2 shows a lateral view of a possible localization of the nozzles on a boat. 
     FIG. 3 shows in detail, the internal structure of an ejector nozzle. 
     In FIG. 4, the arrows show possible maneuvers of hulls provided with the system according to the present invention. 
     FIGS. 5 and 6 show, in a respective axonometric view and transversal section, a variant of an ejector nozzle with internal throttling. 
     FIGS. 7 and 8 show a scheme of two variants of pressing or pulling ejector nozzles, which are particularly fitting on boats used for trawling. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     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 pump(s) 5 housed in the hull and fixed to the bulwarks in determined points by means of pass-through holes. The flow to the nozzle(s) is controlled by means of valve(s) 6 operated with mechanical, hydraulic, or electrical systems, or by engines or other means. 
     The hydraulic system also comprises of one or more pump(s) 5 housed in the hull N, powered by the engine of the boat by means of electromagnetic pulleys, hydraulic or electric transmissions, an autonomous motor energy source of any kind, or by other means. The pump(s) 5, for supplying the thrust to the fluid under pressure, for example, water directly collected from the bottom of the boat through intake 7. 
     The hydraulic system further comprises an internal structure of said nozzles 1, 2, 3, 4, operated by electrovalve(s) 6 and having a discharge in the shape of a throttling venturi pipe 8, for increasing and adjusting the hydraulic thrust by means of the valve(s) 6. The systems operations are directed from a control board 9 which may be 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 briefly described in the following way. 
     The engine of boat N operates a pump 5 by means of pulleys with an electromagnetic clutch. Said pump sucks water from the bottom of said boat N, by means of an intake 7 from the sea. Water is pushed through pipes to nozzles 1,2,3,4, which are individually chosen for the particular maneuver. The nozzles are arranged on the bulwarks and operated by electrovalve(s) 6; 
     when the electric switche(s) provided on the bridge are operated, an electrical signal is supplied to the pulley or clutch to start the pump and, at the same time, to activate the electrovalve(s) chosen for supplying the thrust through fluid ejectment at the desired point(s). 
     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 exploit the thrust in all directions. 
     The system would also be useful in the case of breakdown of the main engines or other moving means, so as to obtain emergency movement. This use would be particularly applicable in sailing-boats or for pulling, at a low speed, fishing boats. 
     In the variant shown in FIGS. 5 and 6, the ejector nozzle consists of a plurality of elements assembled by means of screws 11 and a cylindric body externally threaded 13, with the end section reduced by an internal flange 10 with a central hole 17. The nozzle also has an external counterflange 18, fastened to said body 13 by means of said screws 11 and with the interposition of a sealing gasket 19. The nozzle has a metal ring 12 that is shaped in one single piece with different inclinations that may be fitted to the different shapes of the bulwarks. By means of screws 11, the nozzle design places an external flange 18 in specular coupling with said internal flange 10 which has a central hole 20 of a diameter slightly greater than the one of said central hole 17. Flanges 10 and 18 are sized relative to each other 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. Internal to the bulwalk and fitting around the metal ring 12 a spacer 16 that reorients the plane of the metal ring 12 to be normal to the washer 15 and the nut 14. 
     The installation of the above mentioned nozzle may be briefly described in the following way. 
     A pass-through hole having the same diameter as the external diameter of the cylindrical body 13, is made in the bulwark, after which, a metal ring 12 that has an inclination corresponding to that of the bulwark, is inserted into said hole. 
     The nozzle is secured to the bulwark by tightening the nut 14. The nozzle is connected to the hydraulic circuit, by making use of the remaining threaded part of the cylindric body 13. 
     For mounting the nozzle in small spaces, it is possible to separate the body 13 from the flange 18 by unscrewing screws 11, pre-connecting said body 13 to the hydraulic circuits, coupling the parts through the pass-through hole performed in the bulwark, rescrewing the screws 11 and tightening the nut 14. 
     The variants of the system according to the present invention shown in FIGS. 7 and 8 are particularly suited 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 of FIG. 7, the body of the ejector 13 consists of a curved tubular conduit whose external end is internally reduced by said flange 10. The other end of the elector body 13 shows a threading 21, and a rubber supporting edge 22 for the connection to the hydraulic system. Said ejector forms a single body with external flange 12 adjustable inclinations resulting in perfect fitting to the external curving of the bulwark to which it is applied by means of screws 11. The fluid, pushed by the pump 5, 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. The force generated by the discharged fluid causes frontward motion, if it is turned towards the stern, or backward motion, if it is turned towards the stem. 
     The same function may be fulfilled, according to the present invention, by the variant shown in FIG. 8, consisting of a telescopic forward nozzle, formed by a pipe body 23 of different length. The outer end thereof has a curve 24 that redirects the high pressure fluid in the opposite direction at discharge from its direction when it first enters the pipe body 23. The nozzle is also provided, in the fluid outlet point, with a flange 10. 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, which is fastened to the hull. The ejector of FIG. 8 also has at an inner end, a perforated cap 25 with a sealing gasket 26 which seals cap 25 onto the pipe 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 gasket, the pipe 29 contains a threaded hole 28 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 is stopped by cap 25. The pressurized fluid then flows out of said nozzle from its forward housing in the hull. It is then discharged through flange 10. The reaction effect of the pressurized water discharge exerts a reaction force that moves the boat. 
     When the nozzle has accomplished its task, it is again retracted into pipe 29, due to the intake of fluid under pressure through the threaded hole 28.