AU631361B2

AU631361B2 - Speedboat with two carrier wings

Info

Publication number: AU631361B2
Application number: AU35835/89A
Authority: AU
Inventors: Jan Gielens
Original assignee: Individual
Current assignee: Individual
Priority date: 1988-06-06
Filing date: 1989-05-30
Publication date: 1992-11-26
Anticipated expiration: 2009-05-30
Also published as: DE3884794T2; DE3884794D1; ES2047579T3; AU3583589A; ZA894110B; JPH0285088A; EP0345406B1; EP0345406A1; IL90459A0

Description

COMMONWEALTH OF AUSTRALIA PATENTS AACT 1952 COMPLETE SPECIFICATION NAME ADDRESS OF APPLICANT: Jan Gielens Casimirstraat, 2 Nederokkerzeel 3092 Belgium NAME(S) OF INVENTOR(S): Jan GIELENS I II *1 4.4 1 41

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I I I I 1t1 I C C .1 ADDRESS FOR SERVICE: DAVIES COTLISON Patent Attorneys 1 Little Collins Street, Melbourne, 3000.

COMPLETE SPECIFICATION FOR THE INVENTION ENTITLED: Speedboat with two carrier wings t C t The following statement is a full description of this invention, including the best method of performning it known to me/us:t 4 i0 -la- "Speedboat with two carrier wings" The invention relates to a speedboat comprising a cockpit for at least one pilot for piloting the propulsion means, and two carrier wings.

A preferred object of the invention is to realize a speedboat having a monolithic structure and, despite the absence of movable extending members influencing the piloting, such as for example so-called flaps, which can be piloted at different speeds, and which by increased speed is lifted up out of the water.

According to a first aspect of the present invention there is provided a speedboat comprising a frame with a cockpit for at least one pilot for piloting a propulsion means and two carrier wings, the speedboat comprising a keelwing which at its bottom side ends in the form of a ski, and the propulsion means comprises two air propellers which are each individually orientable.

Embodiments of the invention will now be described by way of example only with reference to the accompanying drawings in which:- Figure 1 is a side view of a speedboat according to an embodiment of the invention.

SA 20 Figure 2 is a top view of a speedboat according to Figure 1.

Figure 3 is a top view of a possible variation of the speedboat according to Figures 1 and 2.

Figure 4 is a front view of the keelwing.

Figure 5 is a bottom view of the keelwing.

Figures 6 to 9 show schematically four successive positions of the speedboat beginning from the standstill position of the speedboat and ending t. in a complete lift out of the water at a corresponding increased speed.

The speedboat according to Figures 1 to 9 comprises a frame 1 in the middle of which is mounted the cockpit for one, and in some cases two pilots.

Lateral wings 3 extend on both sides of the cockpit. They show the sharkprofile, i.e. compared to the delta-profile, it differs by a profile which is strongly rounded-off at the top. The invention is also applicable to a 920730,kayspe.001,35835.spe,l i ;i-i -2speedboat with the delta-profile, although the stability of a speedboat with such a profile does not reach the one of speedboat having a shark-profile. The speedboat described here corresponds thus to the preferred embodiment.

The Figures 2 and 3 relate to two different embodiments which only differ by the fact that the edges of the carrier wings 3 extend according to the form of a pure arc (Figure 2) or they are formed by two straight lines which cross each other (Figure 3).

The cockpit extends in length so far, and is elongated with the profiled middle wing so far, that the directional stability of the speedboat is remarkably increased.

At its bottom side, the speedboat is equipped with an essential element, that is the keelwing 5. This keelwing is mounted approximately at half the length from the prow of the boat. The keelwing has a vertical and a horizontal component. The vertical component 6 determines the distance between the speedboat's keel and the ski 7 which forms the horizontal component of the keelwing.

The form of the keelwing can clearly be seen in the Figures 1, 4, 5 and 6 to 9.

In side view, the keelwing is rounded-off towards the ski 7, while seen

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S 20 in front view it is elongated sharply towards the front. The middle part of the keelwing broadens towards the backside. From an hydrodynamical point of view, more alternatives of the keelwing showed in the Figures can be formed.

The function of the ski 7 of the keelwing is to lift the speedboat out of the water when the speed increases. The keelwing, at least the vertical component thereof, plays an important part in the directional stability which, t in first instance, has to be assigned to the so-called shark-profile.

The propulsion, the lateral stability and the handiness of the speedboat are provided by two orientable air propellers 8, which are mounted at the stern of the speedboat. The propulsion force can be directed by the pilot according to several components which are independent from each other.

This enables, the speedboat, which at higher speed is lifted out of the water and rests on the water by means of its ski, to show remarkable 920730,kayspe.o1,35835.spe,2 c i 1 -3navigation qualities.

The speedboat according to an embodiment of the invention can, independently from its speed and particularly of the direction of its air propellers, take different positions: In absence of the propulsion, the speedboat floats on the water; When the propellers are actuated in order to give a horizontal propulsion, the speedboat is propulsed while still floating on the water; By applying an oblique and downwardly oriented component to the propulsion vector of the propellers, the boat directs itself with the prow out of the water. As the speed increases, the boat lifts out of the water by means of the ski which then lays down on the water; The piloting of the air propellers, by applying them a different vertical and downwardly oriented component, is thus essential, to permit the speedboat to turn without loosing its stability. By orienting the boat propellers are wished, the speedboat reacts immediately; By a dropdown of the propulsion force, the speedboat immediately goes down to the water-level.

At normal speed, i.e. when the speedboat has its I I t t t Ct t 4 S t 4 €44 €44 44t& 920730,kayspe.001,35835.spe,3 .i i -4frame out of the water, the essential pulling force is provided by the ski 7 at the bottom of the keelwing 5. The carrier wings 3 which are operating at the so-called ground-effect due to the proximity of the water-level, also supply pulling force.

Because the pulling force originating from the ski 7 acts relatively close to the rear border 9 of the speedboat, the aerodynamical centre the point relative to which the moment of the total pulling force is, at a given speed, independent of the angle of the speedboat) lies relatively close to the back of the boat. That point lies, in each case, seen in the navigation direction of the speedboat, far behind the speedboat gravity centre. This explains the longitudinal stability of the speedboat.

The lateral stability results from the ground effect of the carrier wings 3. Between the carrier wings and the water-level an over-pressure is built up, 15 which increases with decreasing distance between the carrier wings and the S. water-level. At the upper side of the carrier wings, an under-pressure is built up, which originates from the whirling generated at the front side by the profile. The over-pressure is created under the wing and under-pressure is created above the wing. The pressure differential therebetween is responsible for the carrier force from the wing.

By a lateral heel of the boat, the over-pressure under the carrier wings increases at the side where the distance to the water-level is the smallest, and decrease at the side where the distance is the largest, while the streaming at the upper side is in principle not modified. This explains the origin of the lateral stabilizing torque.

Experiences have proven that the two most important phenomenons which cause the forces on the structure of the speedboat are, on the one hand the hydrodynamical effect on the keelwing, and on the other hand the aerodynamical forces on the wing profile.

The aerodynamical forces which act on the structure can be divided into the ground effect and the action of the profile. The pulling force on that structure due to the action of the profile is in fact small, due to the small ratio j1 920928,p:\oper\kay,35835.spe,4 -4aof the span with respect to the profile depth.

It is also clear that adjustment of both air propellers plays an essential role by assuring the stability of the speedboat.

920928,p:\oper\kay,3583.spe,5 The independent adjustment of both air propellers is then also a main characteristic of the invention. Important is also that the point of action of the forces developed by those propellers on the speedboat lies above the gravity center of the boat.

Finally, a minor construction detail can also be mentioned, which consists in that the extremities of the carrier wings are either pivotable or dismountable. The line according to which the hinged movement, respectively dismounting of the lateral ends of the carrier wings 3, can be realized is indicated by the line 10. By temporary decreasing the width of the carrier wings, certain transport problems are solved in an easy way.

The presence of two hinged or mobile structures of the carrier wings does not impede that a speedboat according to the invention has a monolithic structure.

It will be clear that the invention is not limited to the embodiment described hereabove and that thereto a lot of modifications could be applied, without departing from the scope of the patent application.

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Claims

1. A speedboat comprising a frame with a cockpit for at least one pilot for piloting a propulsion means and two carrier wings, the speedboat comprising a keelwing which at its bottom side ends in the form of a ski, and the propulsion means comprises two air propellers which are each individually orientable.

2. A speedboat as claimed in claim 1, wherein said carrier wings show a shark profile i.e. a delta-form which is strongly rounded at the top.

3. A speedboat as claimed in claim 1, wherein said carrier wings show a delta profile.

4. A speedboat as claimed in any one of claims 1 to 3, wherein said keelwing is mounted at a distance from the prow which corresponds to substantially half the length of the speedboat frame.

A speedboat as claimed in any one of claims 1 to 4, wherein said I. propulsion force generated by the air propellers acts above the gravity centre Si' of the speedboat.

6. A speedboat as claimed in any one of claims 1 to 5 wherein said cockpit is oblong shaped and extends over such a length and height that it improves the longitudinal stability of the speedboat.

7. A speedboat as claimed in claim 6, wherein said cockpit is lengthened by a middle wing. 920730,kayspe.001,35835.spe,6 i -7-

8. A speedboat substantially as hereinbefore described with reference to the accompanying drawings. DATED this 30th day of July 1992 Jan Gielens By His Patent Attorneys DAVIES COLLISON CAVE 920730,kayspe.001,35835.spe,7 L I