AU592775B2 - Sailing boat - Google Patents

Abstract

A body for a sailing boat, at the stern end of which are located devices (14a, 17a) for separating the water from the hull (1), whereby a continuous hydrodynamic transformation of a positive-displacement body into a sliding body is possible, even during movement.

Description

\VELTORGANISATION FtTR GEISTIGES E1QL\,TM PCT Internationales Baro INTERNATIONALE ANMELDUNG VEROFFENTLiCHT N! D TRAIU0F D I INTERNATIONALE ZUSAMMENARBEIT AUF DEM GEBI A~ SEN (PC (51) Internationale Patentklassifikation 4 (11) Internationale Verdffentlichungsnummer: WO 86/ 04557 B63B 1/08, 1/34 Al (43) Internationales Verdffentlichungsdatum: 14. August 1986 (14.08.86) (21) Internationales Aktenzeichen: PCT/DE86/00042 (22) Internationales Annieldedatum: 6. Februar 1986 (06.02.86) SE (europaisches Patent).

Veroffentlicht Mit in tern a tionalem. R ech erch enberich t.

Vor Ablauf dertir Anderungen der Anspriiche :ugelas-f senen Frist. Verdffentlich ung wvird wiederh cit falls Anderungen em treffen.

(31) Prioritatsaktenzeichen: (32) Prioritatsdatum: 698,633 6. Februar 1985 (06.02.85) (33) Prioritiitsland: (71)(72) Anmelder und Erfinder: GOTTLER, Jo [DE/DE]; Hansegartenstr. 6, D-7750 Konstanz (DE).

(74) Anwalt: WVEISS, Peter; Schlachthausstr. 1, D-7700 Singlen a. Htwl. (DE).

(81) Bestimmungsstaaten: AT (europaisches Patent), AU, BE (europdisches Patent), CR (europtiisches Patent), DE (europdiisches Patent), DK, FI, FR (europtiisches Patent), GB (europaisches Patent), IT (europdisches Patent), JP, LU (europiiisches Patent), NL (europiiisches Patent), NO, A,0-P -25SE 8 2. 6.L 25G SEP198 PATENT OFFICE (54) Title: BOAT (54) Bezeichnung: SEGELBOOT 14 "117) Abstract A body for a sailing boat, at the stern end of which are located devices (14a, 17a) for separating the water, from the hull whereby a continuous hydrodynamic transformation of a positive-displacement body into a sliding bd spsi ble, even during movement.

(57) Zusamrnenfass,,:ng Bootsrumpf ffir Segelboot, wo am Heck vor Rumpfende Einrichtungen (14a, 17a) zur Trennung des Wassers von der Rumpfschale vorgesehen sind, wodurch eine kontinuierliche hydrodynamische Umwandlung eines VerdrAnger-Rumpfes in einen Gleit-Rumpf auch wvthrend der Fahrt m~glich ist.

The invention relates to a boat hull with a least one duct -U45- S+C--rn NOCr formed in the hull shell/In o- -qt-e of the;hull.

Basically, the lower the resistance of the boat hull in water, the faster a boat with a specific propelling power can travel.

As known, this is achieved in a racing rowing boat by means of a long narrow hull with a long, thinly tapering stern.

This is achieved in a racing motor boat with a short boat hull and a straight truncated stern.

All water vehicles have the feature that the most desirable hull shape has its optimum properties only at a quite specific speed.

Most water vehicles are classified in three groups, according to their hull shape, namely: 15 water vehicles with displacing hull 4.

water vehicles with semi-planing hull and *c water vehicles wil planing hull.

The advantage cf the displacing hull is low water resistance at low speed and excellent seaworthiness in heavy sea, particularly with waves from astern. However, a great disadvantage of this form of stern is that the water S resistance increases very markedly with the so-called hull S. speed. The suction produced by the stern wave arrests the boat and this can go as far as pulling the boat under the surface of the water, for example when the boat is pulled by strong towing vehicles.

It t The semi-planing hull according to the current state of the art is more desirable in this respect as it causes a strong A -2stern wave to break over the water-line owing to the breaking stern. On the other hand, it has considerable drawbacks in rough sea, particularly with waves from astern, because relatively large waves pass over the boat.

The planing form, for its part, is applicable only to powerfully motorised or quite light boats, because the truncated stern sinks into the water at low speeds and thus produces very high resistance.

A boat with a planing hull which has comb-shaped projections from the bow to the stern is known from FR-A 2 271 975. These comb-like projections also intersect the water-line. However, these comb-like projections merely prevent the water from rising along the hull shell when planing and therefore prevent an increase in the area subjected to the retaining force of the water.

S Fins are also provided on the stern below the water-line.

S They ensure that the planing hull has similar properties to S a displacing hull during slow travel, whereas the hull S planes almost on the water-line and has the property of a planing hull during faster travel.

This form of boat has been found to have the disadvantage

SI,

that indentations and projections have to extend over the S entire hull of the boat. Moreover, they can only impart S the properties of a displacing hull to a planing hull during slow travel. In the case of a displacing hull, neither the projections nor the fins are suitable for making it into a planing hull. In addition, the fins only have the task of reducing wave formation at the stern and 13 erefore of reducing the resistance. However, the wetted /77 A C hot-.

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i 3 surface is increased by the fins and the water friction is therefore increased again.

British Patent GB-A-I 447 A.D. 1909 describes a semi-planing boat hull which, like the floats of sea planes, is provided with steps at right angles to the direction of travel. This causes considerably greater resistance at a low speed of travel. As the speed increases, air collects in the stepped portions, reducing wetting by the water. However, the speed has to be increased quite considerably for this to happen.

A displacing hull is described in GB-A-116 255, in which numerous ventilation flaps are arranged on the stern, through which air is blown into the water by a fan.

The air blown in in this way rises to the surface in air bubbles so that resistance of the boat through the water is not reduced.

L US-A-2 663 276 again describes a ship with air supply pipes S which are arranged on the stern and are provided with c, slits. Below the waterline there are also arranged corresponding flaps which, on the one hand, are used for decelerating the ship and, on the other hand, can expose openings through which air issues from the air supply pipes of the water-line. The water resistance should thus be o reduced to a certain extent by production of an air St cushion. However, the effect thus achieved is minimal.

44 The inventor has set himself the task of developing a boat r S hull which can be converted continuously and hydrodynamically during a stoppage and/or during travel rom a displacing hull with the known advantages into a 6i "]1

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I L i -i i; I- *LliC U31Cp--; I"i~i~-~il*--iiu~wiMitSS~;~ 4 planing hull with the known advantages, and the hull shape can be adapted or is automatically adapted hydrodynamically to the respective speed of travel.

To achieve this object, the air supply duct intersects the water-line and is covered by flexible strips, the front edges of which are fixed on the boat hull while the rear edges can serve for releasing the issuing water from the boat hull.

This enables the stern wave to be broken down above the water-line and, depending on the speed, more or less far below and also to the front of the boat hull and thus prevents it from producing resistance due to its suction.

A boat hull is thus produced which can be adapted hydrodynamically to the optimum form with minimum 15 resistance at any speed.

The devices for breaking down the stern wave preferably intersect the water-line from the top front to the bottom I• rear, i.e. at an acute angle. This means that, even when the stern is immersed quite deeply into the water, the devices are invariably located such that the breaking lines always run in front of the immersion points over the water .t surface in the direction of travel. Otherwise, the air t' supply ducts would fill with water and their effect would be lost.

To achieve the smoothest hydrodynamic conversion of the displacing hull into a planing hull, several devices which t r S may also run at differing angles to one another and to the

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oater surface (water-line) can be arranged in succession on >hC h ~b hull instead of one device with a breaking line.

.X ;f i I -1 4_ 4-- One embodiment proposed that the duct be covered with flexible strips, the positions of which can be varied by mechanical, pneumatic or hydraulic actuating elements. Due to the air issuing here, an air cushion is formed between hull shell and water so suction can no longer occur and reliable separation of the stern wave from the hull is ensured.

In a further embodiment, the duct is covered by resilient strips whilst leaving a slot free.

The strips are arranged in the plane of the hull shell so that it does not represent a speed-impairing enlargement at low speeds. In a further improvement these resilient strips can be designed to be set out. Actuating elements are, in turn, provided for this purpose in the air supply duct.

With the present invention, therefore, the advantages of the displacing hull can be utilised fully at low speeds and r t in rough sea. As the speed increases, the length of the hull can be extended hydrodynamically by the devices described. The speed barrier of the so-called hull speed 4 (2.43 x Length water-line) no longer exists. It is thus possible, for example, to cause a yacht to plane or surf in the same manner as a dinghy because the stern is not pulled downwards. A displacing hull changes into a planing hull.

This is effected by intentionally diverting the stern waves from the hull shell in front of the end of the hull. The stern wave is thus broken from the water-line by the hull and is diverted.

GB-PS 2 098 136 deals with a similar problem. In this (j -6case, the parts are driven out of the bottom of the boat in order to change the shape of the hull, so that the boat planes on the surface of the water at high speed. However, the stern wave is not broken.

Other advantages, features and details of the invention are given in the following description of preferred embodiments and with reference to the drawings.

Figure 1 shows a schematic view of a boat hull.

Figure 2 shows a partially illustrated horizontal section through the stern part of the boat hull along line II-II in Figure 1.

Figures 3 and 4 show further embodiments of a stern part, illustrated according to Figure 2.

Figure 1 shows a hull shell 1 with a stern part 2, a rudder 3 and a keel 4. The lines 5 illustrate the position of actuatable devices for breaking the stern wave.

These devices are described in more detail with reference to various embodiments in Figures 2 to 4.

In the embodiment according to Figure 2, the breaking edge 20 is formed from flexible strips 14 which are sunk and fixed S in the hull shell 1 in the direction of travel but are arranged movably against the direction of travel, so that S" they can be sunk in the hull shell or can also project from the hull shell and thus cover a groove 11 or an air supply 4. I 25 duct 7. However, these strips 14 can also be subjected, for example, to inwardly directed initial tension. Holding elements 15 can be constructed as tension elements if the strips 14 have outwardly directed tension. The position of the strips in relation to the hull shell can then be n controlled by pulling at the tension elements.

-7 If the strips 14 are pulled in completely, they form an end part of the hull shell 1. The position of the strips 14 acting as breaking edge can thus be adjusted as desired both during travel and during a stoppage. This can take place automatically or can be effected under control, for example depending on the speed of the boat.

Figures 3 and 4 show particularly preferred embodiments of the invention.

00 o0 0 o o 0 oo nan o o 0 o o 0 4 0 0 ir 4 000 4 t t t' I 'I( 1 i According to Figure 3, the air supply duct 7 is covered by 10 strips 14a which are arranged substantially flush with the hull shell 1. The strips 14a form with the hull shell 1 a slot 17a from which air can issue.

Figure 4 also shows a similar design, but the strips 14a are movable in design therein. For this purpose, there is 15 provided in the air supply duct 7 a driving means 18 which hydraulically, pneumatically or mechanically drives a driving rod 19 by means of which the strips 14a can be pressed from the plane of the hull shell 1.

The device for breaking the stern wave can be adjusted during a stoppage and also during travel of the boat.

Figures 5 and 6 show especially preferred embodiments of the invention. Figure 5 shows the air supply duct 7 covered by strip 14a disposed substantially flush with the hull shell 1. The strip 14a cooperates with the hull shell 1 to form a slot 17a from which air can emerge.

A similar arrangement is also shown in Figure 6, where however, the strip 14a is constructed to move. For this purpose the air supply duct 7 has a drive means 18, driving (C Z hydraulically, pneumatically or mechanically a drive rod 7a 19 by means of which the strip 14a can be pushed away from a position substantially flush with the hull shell.

The position of the activatable means can be changed during the standstill or during the cruise of the boat.

Modifications and variations such as would be apparent to a skilled addressee are deemed within the scope of the present invention.

t e t t C 1 12

Claims (6)

1. A boat hull with at least one air supply duct which is formed into the hull shell near the stern of the boat hull characterised in that the or each air supply duct intersects the water-line and is covered by one or more flexible strips each strip (14) having a front edge which is fixed to the boat hull and a rear edge which is either movable away from the boat hull, or is immovably mounted substantially flush with the boat hull, the rear edge being arranged so that air from the or each duct (7) separates the stern wave from the boat hull abaft the strips (14) during forward motion of the boat hull.

2. A boat hull according to Claim 1, characterised in that the position of the movable rear edge of each strips (14), relative to the hull shell is controlled in an automatically adjustable manner.

3. A boat hull according to Claim 1 or 2, characterised in that the or each air supply duct is only partially covered by strips (14a) to leave a slot (17a), the strips 20 (14a) being mounted substantially flush with the hull shell

4. A boat hull according to any one of the previous claims, characterised in that the or each air supply duct there is provided with a driving means (18) for a driving rod (109) or the like which pushes the movable rear edges of the strips (14a) away from the position substantially flush with the hull shell A boat hull according to any one of the previous Claims, characterised in that several air supply ducts (7) 8a- each covered by flexible strips (14 or 14a) are arranged in succession on the hull shell

6. A boat hull according to Claim 5, characterised in that the air supply ducts and flexible strips (14 or 14a) are disposed at differing angles to one another and to the water line.

7. A boat hull substantially as hereinbefore described with reference to any one of Figures 2 to 6. DATED NOVEMBER 6 1989 JO GUTTLER By his Patent Attorneys KELVIN LORD AND COMPANY PERTH, WESTERN AUSTRALIA. 0 a 2 S\ r 4 4 4