ULTRA THIN BOAT BODY SUPPORTED BY HYDROFOILS

Abstract: The present invention relates to an ultra thin boat body with improved sailing features, which contains a hull (20) with a nose part (21), middle part (22) and rear part (23), and hydrofoil elements (50) connected to the hull (20) by means of a connection unit (40) in such a way that they can move. The characteristic feature of the invention is that the connection unit (40) has a torsion spring unit (41), and the hydrofoil element (50), with the interposition of the to rsion spring unit (41), is fixed to the hull (20).

Description: ULTRA THIN BOAT BODY SUPPORTED BY HYDROFOILS The subject of the invention relates to an ultra thin boat body which contains a hull with a nose part, middle part and rear part, and hydrofoil elements connected to the hull by means of a connection unit in such a way so that they can move. During the development of shipping it has become widely known that the sailing features of boat bodies can be made more favourable by reducing drag. Overly thin hulls, however, do not have the appropriate stability. Because of this the boat bodies of a determined width are supplemented with hydrofoils, positioned on the part that goes under the water, that can have a favourable effect on the sailing characteristics of the boat. The appropriately designed hydrofoils partially raise the bot hull out of the water while it is moving so reducing the drag, and in a given case increase the stability of the boat body. Such solutions can be seen in US patent No. 3,598,076, US patent No. 4,782,779 and US patent No. 4,915,048. Such versions also exist in which the hydrofoils can be rotated, so depending on the speed of the boat the person steering the boat is able to change the angle of incidence of the hydrofoils and with this the travelling position of the boat. Examples of these constructions can be found in US patent No. 4,579,076 and US patent No. 3,628,486. The deficiency of the constructions that have been published, however, is that the hydrofoils - in the case that they are built in a fixed way - during the movement of the boat body in general only operate appropriately in one speed range, while the experience and skill of the person steering a boat fitted with hydrofoil elements that have been fitted so that they can be moved can have a great effect on the sailing features of the boat, while in the case that they are set badly the existence of hydrofoils can be expressly disadvantageous. Another unfavourable feature is that, up until now, hydrofoil elements have been exclusively used on relatively wide hulled single-hull boats, so the favourable joint effect of them could only be felt between certain limits. SUBSTITUTE SHEET (RULE 25) With the solution according to the invention our aim was to overcome the deficiencies of the known boat bodies and create a version that has exceptionally low drag and allows high speed, good water stability and attitude, and that, furthermore, makes good manoeuvring characteristics possible. The recognition that led to the solution according to the invention was that if a hull is created that is very long and high as compared to its width, in other words ultra thin, to which hydrofoils are connected in a unique way, by a connection unit that is different to those know of then due to the very small travelling resistance and during the movement of the boat body due to the raising forces originating from the hydrofoil elements the task can be solved. In accordance with the set aim the ultra thin boat body with improved sailing features according to the invention, which contains a hull with a nose part, middle part and rear part, and hydrofoil elements connected to the hull by means of a connection unit in such a way so that they can move, is constructed in such a way that the connection unit has a torsion spring unit, and the hydrofoil element, with the interposition of the torsion spring unit, is fixed to the hull. Another criterion of the boat body according to the invention is that the hydrofoil elements are positioned on the two longitudinal sides of the hull. In a possible constructed form of the boat body the hydrofoil element has a fixing zone that can be connected to the connection unit, and there is a front hydrofoil part positioned before the fixing zone and a rear hydrofoil part behind the fixing zone. The operating surface of the front hydrofoil part and the operating surface of the rear hydrofoil part are of different sizes. From the point of view of the invention it can be favourable if the connection unit has an adjustment partial unit connected to the torsion spring unit. In another version of the invention the connection unit has a seating unit and in the seating unit it has one or more catches, the torsion spring unit is formed by deforming, force- absorbing rubber blocks that are parallel along their longitudinal axis, a part of the deforming, force-absorbing rubber blocks is fitted between the catches, and the hydrofoil unit is held between the deforming, force-absorbing blocks. In another different version of the boat body the connection unit has a seating unit and in the seating unit there are one or more catches, the torsion spring unit is formed by coil springs, one end of the coil spring is fixed to the connection unit and the other end is fixed to the fixing zone of the hydrofoil. In a further construction of the boat body the connection unit has a seating unit and one or more catches are positioned in the seating unit, the torsion spring unit is formed by one or more spiral springs, one end of the spiral spring is connected to the connection unit and the other end is fixed to the fixing zone of the hydrofoil. The boat body according to the invention has numerous advantageous features. The most important of these is that due to the unique combination of the long, thin, arrow-like hull and the hydrofoil units a boat body can be formed that has a continuously, automatically changing, speed-dependent draught, which, as a consequence of its ultra thin construction, and due to the low drag, is fast, is not liable to overturn, and still very manoeuvrable with a good attitude. Another advantage is that due to the new type of connection between the hull and the hydrofoil the deck level of the boat body is, when the boat is stationary, close to the water surface, however, when the boat is travelling at its normal speed the deck level rises high above the water. As a result of this unique feature the boat body can be used especially effectively as a rescue boat, as in a stationary, i.e. rescuing position its stable deck close to the water makes getting people out of the water easier, as it rises high out of the water while travelling quickly the waves do not easily break onto the deck of the boat body, even in the case that the gunwales are not too high. A further advantage is that the pre-tensioning of the hydrofoil elements, or the spring force resistance characteπstics can be changed if necessary, so the sailing features of the boat body - within certain limits - can be changed in accordance with the characteπstics of the water being sailed on and the sailing circumstances Another advantage due to the construction different to those known of is that the boat body is significantly less sensitive to the wave motion than the known constructions Due to the self-settmg hydrofoil elements the porpoising, pitching motion occurπng in the waves is also reduced, as the water movement caused by the wave motion moves the hydrofoil elements and with this - forcing the boat body in the direction precisely opposite the wave motion - the movement caused by the wave motion is corrected Still another advantage is that as a consequence of the better sailing features, but mainly the significantly reduced drag and the better manoeuvrability, the boat body fitted with a low output engine gives performance like that of traditional boat bodies fitted with larger engines, so the specific operation cost of boats fitted with the boat body according to the invention is significantly lower The invention in connection with the construction examples is presented in detail on the basis of a drawing On the drawing Figure 1 is the side view of the boat body in partial cross-section, Figure 2 is a view from the direction TJ in figure 1 in partial cross-section, Figure 3 is the side view of a version of the connection unit m partial cross-section, Figure 4 is the side view of another version of the connection unit in partial cross-section In figures 1 and 2 a possible version of the boat body 10 according to the invention can be seen It can be clearly seen that here the boat body 10 consists of a hull 20 and another hull 30 of the same size, which are connected to each other by the connection member 1 1 Apart from connecting the task of the connection member is to provide a place for the engine (not shown on the diagrams) to be attached and other auxiliary units, and also provide a space for the crew The hull 20 is constructed of a nose part 21, a middle part 22 and a rear part 23 and made of generally applied materials, e.g. fibre reinforced resin, just like hull 30 and the connection member 11. It is important to emphasise that the length and width of the hull 20 can vary between wide limits depending on the water sailed on, so a hull 20 destined for freshwater could have a width of 10-15 cm and a length of 2.5-4 m, a sea-going hull 20 could have a width of 10-25 cm and a length of 4-12 m, while an ocean-going hull could have a width of 20-60 cm and a length of 10-27 m. Obviously in the case of hulls 20 of differing proportions the depth of the position of the hydrofoil elements 50 and so the connection units 40 on the hull 20 also differs between 0.4-3.8 m. However, in every case the selection of favourable proportions takes place in consideration of the purpose and other features. As can be seen on figure 2 the hull 20 - and also the hull 30 - is fitted with hydrofoil elements 50. Two hydrofoil elements 50 are placed on the external longitudinal side 24 of the hull and two are placed in the internal longitudinal side 25 symmetrically to the main plane 26 in such a way that the first two hydrofoil elements 50 are fitted to the nose part 21 of the hull 20, while the rear two hydrofoil elements 50 are fitted to the rear part 23 of the hull 20. The hydrofoil elements 50 on the external longitudinal side 24 of the nose part 21 and on the internal longitudinal side 25 of the nose part 21 are fitted to a common axle 54, which axle 54 is fitted into the connection unit 40 fixed to the nose part 21 in such a way so that it may rotate. The hydrofoil element 50 consists of a front hydrofoil member 51, a rear hydrofoil member 53 and a fixing zone 52 situated between them, and the axle 54 is connected to the fixing zone 52. It can also be seen that the operating surface 51a of the front hydrofoil part 51 of the hydrofoil part 50 is smaller than the operating surface 53a of the rear hydrofoil part 53. This surface different is a question of dimensioning, and its extent depends on the size of the boat, its planned running speed and the characteristics of the water on which the boat is navigated, so the construction of the hydrofoil elements 50 and the shape of the front hydrofoil part 51 and the rear hydrofoil part 53 is different in the case of the hydrofoil element 50 of a boat body 10 for sea navigation and in the case of the hydrofoil element 50 of a boat body 10 for river or lake navigation. The connection unit 40 shown in figure 1 has a seating unit 42 in which there is a torsion spring unit 41, which, in the case of this construction, is formed by four rubber blocks 44. The longitudinal axes 45 of the rubber blocks 44 are parallel to each other and to the axle 54 of the hydrofoil element 50. In the seating unit 42 of the connection unit 40 there are catches 43, which are plates butting into the seating unit 42 from the connection unit 40. The rubber blocks 44 serving as torsion spring unit 41 is placed beside these catches 43, so that at the same time they surround the fixing zone 52 of the hydrofoil element 50. The seating unit 42 of the connection unit 40, the catches 43 and the rubber blocks 44 are constructed in a way that there is exactly enough space for the fixing zone 52 of the hydrofoil element 50 and the axle 54 to fit in the area between the rubber blocks 44, that is in the normal position of the hydrofoil element 50 the torsion spring unit 41 does not exert any deviating force on the hydrofoil element 50. When using the boat body 10 according to the invention, the hull 20 and the hull 30 of the boat body 10 go into the water in the same way, and the hydrofoil units - as is shown in figure 1 - are positioned turned off the horizontal so the front hydrofoil part 51 is above the horizontal and the rear hydrofoil part 53 is under the horizontal. With the hydrofoil unit in this state the operating surface 51a and the operating surface 53a look slightly towards the front. When the boat body 10 sets off the forces having an effect on the operating surface 5 la of the front hydrofoil part 51 and on the operating surface 53a of the rear hydrofoil part 53 of the hydrofoil unit 50 the due to the relative speed and acceleration between the water and the boat body 10 cause the hydrofoil unit 50 to turn anticlockwise - with respect to figure 1 - in other words the hydrofoil unit 50 tries to get into a position as close to horizontal as possible. While the hydrofoil unit 50 turns against the torsion spring unit 41, due to the position of the hydrofoil unit 50 the boat body 10 starts to rise and increasing the speed means that an increasingly smaller part of the boat body 10 remains under the water surface Due to the reduction of liquid-replacement, however, the mass forces from the boat body 10 on the hydrofoil unit 50 grow Due to the increase of buoyancy, the mass forces and speed duπng the lifting of the boat body 10 the rotary force on the hydrofoil unit, and, furthermore, the deformation energy stored in the torsion spπng unit 41 equalise, at this time the hydrofoil element stays in the given position and the boat body 10 does not rise any further, it just planes through the water Naturally a change in the speed has an effect on the balance of forces and also on the amount that the boat body 10 πses When reducing the speed of the boat body 10 due to the change of the forces on the hydrofoil units 50 the deformation energy stored in the torsion spring unit 41 of the connection unit 40 changes to a restoπng force and tries to turn the axle 54 of the hydrofoil unit 50, and through this rotating the fixing zone 52 backwards so turning the front hydrofoil part 51 and the rear hydrofoil part 53 of the hydrofoil 50 in a clockwise direction - regarding the situation shown in figure 1 On becoming stationary the hydrofoil unit 50 returns to its base position On figure 3 a connection unit 40 can be seen, in which the torsion spπng unit 41 placed in the seating unit 42 is formed by three coil spπngs 47 One end 47a of the individual coil spπngs is fixed to the catch 43 placed in the seating unit 42 of the connection unit 40, while the other end 47b of the coil spπng is connected to the adjustment partial unit 46 fixed to the fixing zone 52 of the hydrofoil unit 50 The task of the adjustment partial unit 46 is to give the coil spπng 47 that forms the torsion spπng unit 41 the necessary pre-tensionmg in accordance with the characteπstics of the water being sailed on It can be seen that the hydrofoil unit 50 is in a position turned off the hoπzontal, and also that the operating surface 51a of the front hydrofoil part 51 in this case is smaller than the operating surface 53a of the rear hydrofoil part 53 Figure 4 differs from the previous only in that here the torsion spring unit 41 positioned in the seating unit 42 of the connection unit 40 is a spiral spring Here also one end 48a of the spiral spπng 48 is connected to the catch 43 of the seating unit 42, while the other end 48b is fixed to the fixing zone 52 of the hydrofoil unit 50 It needs to be mentioned here that the pre-tensionmg of the hydrofoil unit can not only be changed with the adjustment partial unit 46 This task can also be solves by rubber blocks 44, coil spπngs 47 and spiral spπngs with different spπng power into the seating unit 42 It is also important to emphasise that the hull 20 can not only be used in catamaran-type boat bodies 10, a version may be imagined where the boat body 10 consists of a single hull 20. In the case in order to retain stability the hull 20 needs to be given the necessary keel Naturally constructions can be formed in which the boat body 10 actually consists of three hulls 20. The boat body according to the invention can be used well on all types of water, in the case of all types of watercraft, but it is especially good for sailing boats, powered sport and hobby boats, furthermore, rescue and military boats, where good manoeuvrability, resistance to capsizing and speed are basic requirements. List of references boat body 11 connection member hull 21 nose part 22 middle part 23 rear part 24 external longitudinal side 25 internal longitudinal side 26 main plane hull connection units 41 torsion spring unit 42 seating unit 43 catch 44 rubber block 45 longitudinal axis 46 adjustment partial unit 47 coil springs 47a one end 47b other end 48 spiral spring 48a one end 48b other end hydrofoil element 51 front hydrofoil member 51a operating surface 52 fixing zone 53 rear hydrofoil member 53a operating surface 54 axle

Claims: C l a i m s 1. Ultra thin boat body with improved sailing features, which contains a hull (20) with a nose part (21), middle part (22) and rear part (23), and hydrofoil elements (50) connected to the hull (20) by means of a connection unit (40) in such a way so that they can move, characterised by that the connection unit (40) has a torsion spring unit (41), and the hydrofoil element (50), with the interposition of the torsion spring unit (41), is fixed to the hull (20). 2. Boat body as in claim 1, characterised by that the hydrofoil elements (50, 60) are positioned on the two longitudinal sides (24, 25) of the hull (20). 3. Boat body as in claim 1 or 2, characterised by that the hydrofoil element (50) has a fixing zone (52) that can be connected to the connection unit (40), a front hydrofoil part (51) positioned before the fixing zone (52), and a rear hydrofoil part (53) behind the fixing zone (52). 4. Boat body as in claims 1 to 3, characterised by that the operating surface (51a) of the front hydrofoil part (51) and the operating surface (53a) of the rear hydrofoil part (53) are of different sizes. 5. Boat body as in claims 1 to 4, characterised by that the connection unit (40) has an adjustment partial unit (46) connected to the torsion spring unit (41). 6. Boat body as in claims 1 to 5, characterised by that the connection unit (40) has a seating unit (42), and in the seating unit (42) it has one or more catches (43), the torsion spring unit (41) is formed by deforming, force-absorbing rubber blocks (44) that are parallel along their longitudinal axis (45), a part of the deforming, force-absorbing rubber blocks (44) is fitted between the catches (43), and the hydrofoil unit (50) is held between the deforming, force-absorbing rubber blocks (44). 7. Boat body as in claims 1 to 5, characterised by that the connection unit (40) has a seating unit (42), and one or more catches (43) are positioned in the seating unit (42), the torsion spring unit (41) is formed by coil springs (47), one end (47a) of the coil spring (47) is fixed to the connection unit (40), and the other end (47b) is fixed to the fixing zone (52) of the hydrofoil (50). 8. Boat body as in claims 1 to 5, characterised by that the connection unit (40) has a seating unit (42), and one or more catches (43) are positioned in the seating unit (42), the torsion spring unit (41) is formed by one or more spiral springs (48), one end (48a) of the spiral spring (48) is connected to the connection unit (40), and the other end (48b) is fixed to the fixing zone (52) of the hydrofoil (50).

Inventors: SUBERT ISTVAN, SUBERT, ISTVAN
Applicants: SUBERT ISTVAN, SUBERT, ISTVAN
Application year: 2000
Main classification: B63B1
IPC codes: B63B1