PROPULSION FOR BOATS CONSISTING OF JETS OF AIR DRAWN INTO A PAIR OF LONGITUDINAL CHANNELS UNDER THE HULL

Abstract: Propulsion for boats (10) by jets of compressed air inside a pair of parallel longitudinal channels (11) open underneath, placed below the hull, substantially horizontal, one on each side of a third wider axial channels (13) suitable for formation, as a consequence of the movement of said boat, of a cushion of air that sustains the hull when sliding over the water.

Description: Title : "PROPULSION FOR BOATS CONSISTING OP JETS OP AIR DRAWN INTO A PAIR OP LONGITUDINAL CHANNELS UNDER THE HULL" Present state of the art It is well known that boats can be propelled - heteronomously (such as by a sail) - autonomously (where the so ' urce of energy is generated wi¬ thin the boat) such as bywater jet propulsion or by a marine screw propeller. ' Water "jet propulsion is advantageous at speeds greater than 70 knots and creates problems in the structure and system as a high rate of flow is needed for satisfactory perfor¬ mance- Marine screw propulsion (from 2 to 6 blades) creates prob- lems as, if a certain number of revolutions is exceeded, cavitation occurs w ' ith reduced thrust due to progressive interruption of thenappeand earlier corrosion of the propel¬ ler. To drive the propeller alternating marine internal combus- tion engines cooled by sea water are generally used, but their efficiency is considerably less than that of land-based engines. The above invention eliminates or appreciably lessens these drawbacks by means of a system which creates a high thrust and at the same time allows the boat to ride on a cushion of aid as will be explained below. Description of the invention Subject of the invention is a system of propulsion for boats obtained by thrust from jets of air inside a pair of equal rectilinear parallel channels, open on the downward side, symmetrical in relation to the longitudinal axis, mounted under the hull, substantially flat, placed one on each side of a third and broader rectilinear axial channel. While in movement, the hull is therefore practically rest- ing on the air entering the pair of channels and on that generated in the middle channel due to boat movement itself.. All this causes the boat to be raised above the surface of the water thus reducing sliding friction. The air is sucked in near the bow end by an internally mounted engine-driven propeller and is carried in two tu- bular ducts inside the hull, flowing out through apertures at the summit of the pair of channels near the stern. The propeller is driven by an internal combustion engine of the type used on land. The mouths for air outflow are fitted with on-off valves and with directional conveyors to stop the' ets in one chan nel or the other and change their direction thus driving the boat forward or slowing it down as desired. On each of its sides, respectively towards bow and stern, there are at least two nozzles fitted with on-off valves connected to the -tubular parallel ducts carrying compressed air so that by opening one or other of the nozzles, the boat can be turned round in either direction as desired and can make any other limited movements that may be re¬ quiredwithin a small space. The on-off valves and directional conveyors are served by hydraulic cylinders operated by a set of controls, placed on a dashboard and the like, from a unit driven by the pro_ peller engine. The cross section of the central channel is substantially in the shape of a wide arc joined at the ends by narrower arcs. The section of the channels placed side by side is through out substantially semi-circular. The hull has substantially vertical sides and a base which is practically formed of the three said channels and of the lower exire ities of the sides which project laterally, in convex form, in relation to the external vertical sides of the lateral channels and at a level above their base. These projecting sides therefore help to keep the boat steady when lying still or moving slowly while, when at a certain speed, they are practically off the water thereby reducing friction. The nozzles are placed in the small longitudinal groove formed between the external vertical sides of the pair of channels and the lateral convex sections of the bottom of the hull. The directional conveyors of the tubular ducts carrying compressed air are formed of a sort of vertical arched groove, with the concave side towards air jet inflow, ar- ticulated crosswise to its axis and to the channel in which each conveyor is mounted. Said articulation makes possible its partial or complete extraction in the space occupied by the channel,compelling the jet of compressed air flowing to the stern to turn down wards and towards the bow, to slow down the boat or put it into reverse as required. The controls are arranged together in a set of six levers of which two intermediate lateral levers are for "normal forward" movement, a pair of front ones respectively for "forward to the left" and "forward to the right", a pair at the back for "minimum left" and"minimum right". When moved together the front pair of levers give forward move ment or stop the boat while if the back pair are moved t_ gether they stop the boat or reverse it. The characteristics and purposes of the invention will be still clearer from the following example of its execution illustrated by drawings. Examples of execution Pig. 1 Side view. Pig. 2 View from above Pig. 3 View from below Pig. 4 Back view Pig. 5 Partial longitudinal section Pig. 6 " View from above with some of the upper part of the hull cut away Pig. 7 Partial longitudinal section with directional con¬ veyors pulled out, for reversing the boat Pig. 8 Detail of the propeller Pig. 9 Detail of the dashboard The boat (10) is formed of a hull having a substantially horizontal base and vertical sides. Underneath the hull there are two parallel channels, sym¬ metrical in relation to the longitudinal axis, having sec_ tions in the form of an arch of a circle (11), (12), one on each side of a wider central channel (13). At its sides the hull has slightly projecting oonvex lon¬ gitudinal zones (14), (15). The external sides (16), (17) of the lateral channels are substantially vertical and connect with the convex zones by means of a longitudinal groove. The ste n (20) is substantially vertical. The bow (22) is steeply inclined, merging gently into the variously shaped base already described, so as to present a substantially smooth and continuous surface. Propulsion is given by a land-type internal combustion en gine (25) which, with a shaft (26), a clutch (28), a rota ting joint (30) and an intermediate shaft (31), inclined at nearly 45°, drives a-six-bladed propeller (32) mounted close to the front of the hull at its uppermost point. The joint box is supported by a cross journal (33) while the end of the intermediate shaf (31) can rotate in the bushing (34) supported by the cross journal (35). The cross journals (33), (35) are fixed to the sides of the cone-shaped chamber (36) which divides into two paral- lei horizontal tubular ducts (37), (38) through the widely curving connecting sections (40), (41). Near the stern (20) these ducts lead into the mouths (42), (43) which open into the summit of the lateral channels. Close to said mouths the valves (44), (45) are mounted on the ducts. In front of said mouths, transversally to the parallel channels (11), (12), the directional conveyors (46), (47) are mounted, each one formed of a short arched channel which can be extracted from the hull and, by means of arms (50), (51), rotating round the horizontally lying articu¬ lations (48), (49) transversal to the channels. On the external vertical sides (16), (17) of the channels, at the poiπt of the groove formed with the lateral convex zones at the base of the hull, there are four nozzles (60), (61), (62), (63) connected to the ducts (37), (38) and fitted with regulating on-off valves (64), (65), (66), (67) . The on-off valves (44), (45) connected to said ducts are operated by the hydraulic cylinders (68), (69) by means of levers (70). The directional conveyors (46), (47) are worked by the hy¬ draulic cylinders (71), (72) by means of small levers(73) fixed to the articulation pins (48), (49) of said convey¬ ors. The nozzle valves are operated by hydraulic cylinders(74), (75), (76), (77). All the hydraulic cylinders for the valves and for the directional conveyors are connected to the hydraulic drive unit (18) by means of sets of tubes (80) and (82) to and from said unit. The main controls are placed on the boat's dashboard(19) and in particular the unit (23) for operating the tubular duct valves and for operating the directional conveyors, the unit (24) for operating the valves in the lateral no2; zles, and the accelerator (93) of the engine. Unit (23) comprises (see Pig. 9) the central levers (101), (102) for driving the boat straight forward, the front levers (103), (105) respectively for "forward left" and "forward right", and the back levers (104), (106) respec¬ tively for "minimum left" and "minimum right". When moved together, the levers (103), (105) send the boat forward and stop it. When moved together, the levers (104), (106), slow the boat down, stop it, put it into reverse. The unit (24) in turn comprises the levers (107), (108), (109), (110) for working the valves in nozzles (6θ),(63). The units (23), (24) act on various hydraulic cylinders through the drive unit (18) already referred to. On the bonnet (43) of the bow, there is a grating (121) through which air is drawn in by the propeller. At the top of the boat can be seen the seats (122), the windscreen (123) and the protective rail (124). As shown in Pig. 8, the propeller (125) nas preferably six blades like (126). Operation By starting up the propeller, the air it sucks in through the grating on the bonnet of the bow, passes through the duct mouths and .into the pair of longitudinal channels pushing the water out of them and at the same time caus¬ ing the boat to rise on the water and move forward. Due to the effect of the boat's movement the central chan- nel also fills up with air from the lower part of the bow where it enters, contributing to sustain the hull on what is practically a cushion of air. Por braking or reverse movement, it is sufficient to ex¬ tract the arched directional conveybijs (Pig.7) to an ade- guate extent, in order to reverse the direction of the air jets inside the pair of channels pushing the air to¬ wards the bow. Similarly, by completely or partially preventing air from issuing from one of the two ducts, the boa t can be direc_ ted to the right or left as desired. Movements to position the boat in limited spaces, as in ports, are easily made by keeping the duct valves closed and operating the valves in the lateral nozzles. Por example, by simultaneously opening the front left and back right nozzles the boat will turn round clockwise. Advantages These are evident. Even using a land-type engine, thrust can be applied to the boat by a couple of parallel forces generated in one direction or the other under the hull. The air cushion created in the lateral channels and in the central chan- nel permits the hull to move over the water with minimum friction and therefore with maximum efficiency. By graduating the value of the couple and' the direction of forces, movement can be made forward, backwards or in any direction. As application of the invention has been described as an example only not limited to this, it is understood that any equivalent application of the inventive concepts des_ cribed and any product executed and/or in operation in accordance with the characteristics of the invention will be covered by its field of protection.

Claims: AMENDED CLAIMS [received by the International Bureau on 30 June 1987 (30.06.87) original claims 1 - 11 replaced by amended 1 - 11 (4 pages)] 1. System of propulsion and braking for boats characterized in that forward and backward propulsion and braking are ob¬ tained by thrust from jets of compressed air inside a pair of equal rectilinear parallel channels ( 11), ( 12) open below placed underneath the hull, subs antially flat, one on each side of a third rectilinear, longitudinal axial wider chan¬ nel ( 13) open below, so that when in movement, the hull is practically supported by the air drawn into the pair of cha nels (11), (12) in a lateral position, and by the air genera in the centrally placed channel ( 13), due to the effect pr duced by movement of the boat itself, all this raising the boat considerably on the water and greatly reducing frictio 2. System of propulsion and braking for boats as in claim I, characterized in that the air is drawn in by an internal motor-driven propeller (32), placed practically in the bow (22), and is conveyed into two ducts (37), (38) inside the hull, the outlet of said ducts being through mouths (42), (43) placed at the summit of the lateral channels ( 11), (12) in proximity to the stern (20). 3. System of propulsion and braking for boats as in claim 2, characterized in that the propeller (32) is driven by a land-type internal combustion engine (25). 4. System of propulsion and braking for boats as in claim 2, characterized in that the mouths (42), (43) for emission of the jets of air are served by on-off valves (44), (45) and by directional conveyors (46), (47) to cause both in¬ terruption of the jets in one or other channel (11), (12) and change of air direction enabling the boat to proceed forwards and backwards, in any direction, and to be slowed down . 5. System of propulsion and braking for boats as in claim 1, characterized in that on each side of said boats, in a practically symmetrical position in relation to the trans- versal axis of the boat, two nozzles (60-63) are placed, supplied with on-off valves (64-67) connected to the com¬ pressed air ducts (37-38) in order to determine, when one nozzle or the other opens, a rotating movement by the boat (10) in one direction or the other and any movements required to position the boat in restricted spaces. 6. System of propulsion and braking for boats and in claims 3, 4 and 5 characterized in that the on-off valves (44), (45), (64), (65), (66), (67) and the directional conveyors (46), (47) are served by hydraulic cylinders (68), ( 69) , (71 ) , (72) , (74), (75), (76), (77), governed, by means of a hydraulic driv unit (18) moved by the propeller's (32) engine (25), by con¬ trol units (23), (24), laced on the dashboard (19), or the like. 7. System of propulsion and braking for boats as in claim 1, characterized in that the constant transversal section of the central channel (13) is substantially that of a wide arc, joined at its ends by smaller arcs, while the constant sec¬ tion of the lateral channels (11), (12) is that of a semicircl 8. System of propulsion and braking for boats as in claim 1, characterized in that the sides of the hull are substantially verticle and its base is practically formed of the three chan nels ( 11 ) , ( 12) , ( 13) placed side by side, and by the lower extremities (14), (15) of the sides projecting convexly in re¬ lation to the external vertical sides (16), (17) of the later- al channels (11), ( 12) and higher than the bottom of said chan nel so that when the boat is stationary or is moving slow¬ ly, said projecting extremities ( 14), ( 15) help to keep it stable while, when the boat ( 10) is moving fast, they are practically clear of the water thus reducing friction. 9. System of propulsion and braking for boats, as in claims 5, 8 characterized in that the nozzles (60), (63) are placed in the longitudinal groove created by the junction point of the lower convex extremities ( 14), ( 15) of the sides of the hull ith the external vertical sides ( 16), ( 17) of the pair of channels ( 11), ( 12) on the bottom. 10. System of propulsion and braking for boats as in claim 4 characterized in that the directional conveyors (46), (47) are formed by a sort of vertical arched groove with the con¬ cave side turned towards the inflow mouths of the air jets with articulations (48), (49) practically on their transver¬ sal axis to permit partial or total extraction in the spaςe of the channels ( 11), ( 12) and force the jet of compressed air directed towards the stern (20) to change direction down wards and towards the bow (22) so that the boat ( 10) can be slowed down or put into reverse. I I. System of propulsion and braking for boats as in claim 6, characterized in that the controls (23) are associated in a set of six levers, the two lateral intermediate levers ( 101), ( 102) of which are for "normal forward movement™, the two front ones ( 103), ( 105), as a pair, respectively for "lef forward" and "right forward", the two back ones ( 104), ( 106), as a pair, for "minimum .lefe" and "minimum right", the front pair ( 103), ( 105), if worked together, making possible "for¬ ward movement" or "stopping" and the back pair ( 104), ( 106), if worked together, stopping the boat or putting it into re- verse, such effects being obtained by adequate automatic devices in the hydraulic drive unit (18), determining the necessary movements in the on-off valves (44), (45) on the ducts (37), (38) for compressed air and in the directional conveyors (46), (47).

Inventors: SOLARI FRANCO, SOLARI, FRANCO
Applicants: SOLARI FRANCO, SOLARI, FRANCO
Application year: 1986
Main classification: B63B1
IPC codes: B60V1, B60V3, B63B1, B63H11, B63H19