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Title:
COMPENSATORY SAIL
Document Type and Number:
WIPO Patent Application WO/2018/220448
Kind Code:
A1
Abstract:
The compensatory sail without a mast resolves the problem of aerodynamic forces and moments by eliminating them. It enables the elimination of the mast. I.e. the mast is replaced by 2 sail supports (2). The sail (1) is locked in the top position and pretensioned through the pulley (3), rope (3.1) and holder (1.1), at the point (3.2) on 1/3 of the depth of the top aerodynamic sail profile (1), and via the bottom holder (4) (boom) and the fulcrum (5) in the bottom, which is located on 1/3 of the depth of the bottom aerodynamic sail profile (I). The fulcrum (5) connects the bottom holder (4) with the vessel (P). The sail supports (2) are tilted backwards by the angle (alfa 1) and clamped with stays (2.5), (2.5.1), (2.6) and (2.6.1). The sail (1) can be rotated around the axis between the upper point (3.2) and the bottom fulcrum (5), and can be steered via a rope with a block-and-tackle pulley (6) or through a mechanical system in the fulcrum (5). The sail (1) can be trimming by loosening the rope (3.1) and foldingit in the bottom holder (4).

Inventors:
ŠIFRER ERIK (SI)
Application Number:
PCT/IB2018/050469
Publication Date:
December 06, 2018
Filing Date:
January 25, 2018
Export Citation:
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Assignee:
MIDES DESIGN D O O (SI)
International Classes:
B63H9/10; B63B15/00
Domestic Patent References:
WO2009074832A22009-06-18
WO2007009740A12007-01-25
Foreign References:
US5423274A1995-06-13
US5231943A1993-08-03
US2364578A1944-12-05
US0792924A1905-06-20
NL8600661A1987-10-01
US5088431A1992-02-18
SI0989939T12002-06-30
SI22619A2009-04-30
SI22790A2009-12-31
SI9500182A1996-12-31
Attorney, Agent or Firm:
KETNER, LEGAL CONSULTANCY, REPRESENTATION AND PROTECTION, LTD. (SI)
Download PDF:
Claims:
Patent claims

1. The compensatory sail without a mast is characterized by the fact that the sail (1) is on the upper side through the holder (1.1) clamped in point (3.2), while on the bottom side it is clamped through the bottom holder (4) in the fulcrum (5) and can rotate freely around the clamping axis.

2. The compensatory sail without a mast is, according to claim 1, characterized by the fact that it has no mast, but a sail (1) on each side of the vessel, transversely to the vessel (P) is supported by two sail supports (2).

3. The compensatory sail without a mast is, according to claim 2, characterized by the fact, that both sail supports (2) are pretensioned through the support (2.9) and stays (2.7) and (2.8) which also can be combined into one stay and are fixed to the upper and lower end of the sail support (2), while centrally they are supported by a crossbeam (2.9) determining the dimension or force of pretensioning.

4. The compensatory sail without a mast is, according to claim 3, characterized by the fact that the length of the crossbeam (2.9) is determined as factor of product between the factor (xx) and the length of the sail support (2), while the factor (xx) ranges from 0.05 to 0.15.

5. The compensatory sail without a mast is, according to claim 2, characterized by the fact that both sail supports (2) tilt backwards towards the stern (K) of the vessel (P) at the angle (alpha 1) ranging between 1 to 15 angular degrees.

6. The compensatory sail without a mast is, according to claim 2, characterized by the fact that both bottom-end sail supports (2) are fixed in the point (2.2) with a hinge via a pin (2.S) and holder (2.N) which are mounted on the external edges of the vessel (P), while at the top end they converge to one another and come into contact through a connecting coupler (3.3).

7. The compensatory sail without a mast is, according to claim 2, characterized by the fact that the two clamping positions (2.2) of the holder (2.N) to the vessel P are on the left and right side of the vessel (P) and run in the same transverse plane through the vessel (P) as the fulcrum (5).

8. The compensatory sail without a mast is, according to claim 1, characterized by the fact that the pulley (3) is clamped in the middle of the connecting coupler (3.3) and withstands the forces of sail tensioning (1) and the components of the lift aerodynamic forces of the sail (1) through the rope (3.1) that is clamped in the point (3.2) to the holder (1.1) which is clamped to the top part of the sail (1).

9. The compensatory sail without a mast is, according to claims 1 and 8, characterized by the fact that the rope (3.1) travels through the pulley (3) and is at the upper part clamped to the holder (1.1) at the point (3.2) on the length ranging from 1/10 to 1/2 of the upper depth of the aerodynamic sail profile (1), while on the other side it is clamped to the vessel (P) using any known manner.

10. The compensatory sail without a mast is, according to claims 1 and 9, characterized by the fact that the bottom part of the sail (1) is clamped to the bottom holder (4) (boom) which transfers forces of pretensioning of the sail (1) and components of the aerodynamic forces of the sail (1) to the vessel (P).

11. The compensatory sail without a mast is, according to claims 1 and 10, characterized by the fact that the bottom holder (4) also has the function of storing of a partly rolled sail (1) when the sail (1) is shortened, or of a fully folded sail (1) when the sail (1) is completely stored in the bottom holder (4).

12. The compensatory sail without a mast is, according to claim 1, characterized by the fact that the bottom holder (4) is clamped to the fulcrum (5), around which the bottom holder (4) can rotate with the sail (1), at 1/10 to 1/2 of the bottom depth of the aerodynamic sail profile (1).

13. The compensatory sail without a mast is, according to claims 1 and 11, characterized by the fact that pockets can be created for the sail (1) in the direction of wind flow, which are installed with a custom number of tailor designed profile bars (1.2) which shape the sail (1) into the desired aerodynamic profile.

14. The compensatory sail without a mast is, according to claim 1, characterized by the fact that the entry edge (2.V) of the sail (1) is not perpendicular to the sailing line or vessel (P), but is rather displaced towards the stern (K) by the angle (alpha 2) which ranges from 5 to 35 angular degrees.

15. The compensatory sail without a mast is, according to claim 2, characterized by the fact that the sail supports (2) may be created in cross-section or profile (P2) in the form of an aerodynamic profile.

16. The compensatory sail without a mast is, according to claims 1 and 11, characterized by the fact that the entry edge (2.V) and exit edge (2.1) of the sail (1) form a specific geometrical figure which is at the top by the holder (1.1) narrower than at the bottom at the clamping of the sail (1) in the bottom holder (4).

17. The compensatory sail without a mast is, according to claims 1 and 2, characterized by the fact that both sail supports (2) may tilt backwards towards the stern (K) of the vessel (P) at an angle (alpha 1) ranging from 5 to 35 angular degrees.

18. The compensatory sail without a mast is, according to claim 2, characterized by the fact that stays (2.5) and (2.6) are secured with a hinge to the sail supports (2), namely at the deck height ranging from 1/2 to 3/4 of the length of sail supports (2).

19. The compensatory sail without a mast is, according to claim 2, characterized by the fact that stays (2.5) and (2.6) are clamped with a hinge to the vessel (P) in points (2.3) and (2.4) which are at a distance from the point (2.2) of the bottom clamping of the sail supports (2) by the factor (X) which is defined as (0.05 to 0.5) times the length of the sail support (2).

20. The procedure of trimming or rolling the compensatory sail without a mast is, according to claim 1, characterized by the fact that during trimming or rolling the sail (1) is wound to the shaft which is installed and mounted on the bottom holder (4), while on the upper side we release it via the pulley (3) through runs the rope (3.1) which is in point (3.2) clamped to the sail (1) via the holder (1.1) and vice versa.

21. The procedure of controlling the sail without a mast is, according to claims 1 and 2, characterized by the fact that the gears of the fulcrum (5) of the sail (1) which can be of custom technical design are connected with the steering or control loop to the autopilot (AP) which is connected to the helm (K ) for the purpose of vessel (P) navigation.

AMENDED CLAIMS

received by the International Bureau on 01 October 2018 (01 .10.2018)

[Claim 1] [Amended] The compensatory sail without a mast is characterized by the fact that one sail (1) is on the upper side via the upper holder (1.1) rotatably mounted at the point of fitting (3.2), which lies on the upper holder (1.1) at a distance of 1/10 to ½ of the length of the upper depth of the aerodynamic profile of the sail (1), the rotation around the point of fitting (3.2) is carried out only via the pulley (3), the rope (3.1) and the upper holder (1.1) (which is stitch in to the sail) and at the foot of the sail (1) via the bottom holder (4) on which a pivot (5) is installed and a tension system, while it transfers the pre -tensioning forces of the sail (1) and the lifting forces of the sail (1), and it lies at a length of 1/10 to ½ of the depth of the lower aerodynamic profile of the sail (1), the rotation of the bottom holder (4) is possible up to the point where the bottom holder (4) touches the backstay (2.5) left and right.

[Claim 2] [Amended] The compensatory sail without a mast is, according to claim 1,

characterized by the fact that it has no mast, but one tense or loose, according to the operation, trapezoid shape sail (1) to the bottom holder (4), sail is supported on each side of the vessel, transversely to the vessel (P) by two, outwardly bent through a lateral beam (2.9) pre-tensioned sail supports (2) having the shape of an upside-down, pre-tensioned letter "V" without a central connection, i.e. a bar between the two sail supports, the supports are additionally attached with the backstay (2.5) and forestay (2.6) to the mid sides of the edge of deck (2.3), (2.4).

[Claim 3] [Amended] The compensatory sail without a mast is, according to claim 2,

characterized by the fact, that both sail supports (2) are pretensioned through (2.9) a side lateral beam and stays (2.7) and (2.8) which also can be combined into one stay and are fixed to the upper and lower end of the sail support (2), the length of the side lateral beam (2.9) determines the dimension of the cross -section of the sail supports (2) in which sail (1) moves and the force of pretensioning.

[Claim 4] [Amended] The compensatory sail without a mast is, according to claim 3,

characterized by the fact that the length of the lateral beam (2.9) is determined as factor of product between the factor (xx) and the length of the sail support (2), while the factor (xx) ranges from 0.05 to 0.15.

[Claim 5] [Cancelled]

[Claim 6] [Cancelled]

[Claim 7] [Amended] The compensatory sail without a mast is, according to claim 2,

characterized by the fact that the two clamping positions (2.2) of the holder (2.N) to the vessel P are on the left and right side of the vessel (P) and run in the same transverse plane through the vessel (P) as the pivot (5) on bottom holder (4).

[Claim 8] [Cancelled]

[Claim 9] [Cancelled]

[Claim 10] [Cancelled]

[Claim 11] [Amended] The compensatory sail without a mast is, according to claims 1

characterized by the fact that the bottom holder (4) also has the function of storing of a partly furled trapezoid loosed sail (1) when the sail (1) is shortened, or of a fully furled sail (1) when the sail (1) is completely stored in the bottom holder (4) and provides a linear and infinite number of sail shortenings (1).

[Claim 12] [Amended] The compensatory sail without a mast is, according to claim 1,

characterized by the fact that the bottom holder (4) is clamped to the pivot (5), around which the bottom holder (4) can rotate with the sail (1), at 1/10 to 1/2 of the bottom depth of the aerodynamic sail profile (1) until the point where the bottom holder touches the backstays (2.5).

[Claim 13] [Amended] The compensatory sail without a mast is, according to claims 1 and 11,

characterized by the fact that pockets can be created for the sail (1) in the direction of wind flow, which are installed with a custom number of tailor designed profile bars (1.2), which shape the sail (1) into the desired aerodynamic profile.

[Claim 14] [Cancelled]

[Claim 15] [Amended] The compensatory sail without a mast is, according to claim 2,

characterized by the fact that the outwadly bent via side latteral beam sail supports (2) may be shaped in cross-section or profile (P2) in the form of an aerodynamic profile which are pointing into the direction of wind flow.

[Claim 16] [Amended] The compensatory sail without a mast is, according to claims 1 and 11 ,

characterized by the fact that the entry edge (2.V) and exit edge (2.1) of the one tensioned sail (1) form a specific geometrical shape - in the form of a truncated pyramid, a trapezoid which is at the top by the stitch in upper holder (1.1) - narrower than at the bottom at the clamping of the sail (1) in the bottom holder (4).

[Claim 17] [Cancelled]

[Claim 18] [Amended] The compensatory sail without a mast is, according to claim 2,

characterized by the fact that stays (2.5) and (2.6) are secured with a hinge to the each sail supports (2), namely at the deck height ranging from 1/2 to 3/4 of the length of sail pretensioned outwardly bent supports (2) and thus forming the letters "Y" or "V".

[Claim 19] [Cancelled] [Claim 20] [Amended] The procedure of shortening or furling the compensatory sail without a mast is, according to claim 1, characterized by the fact that during shortening or furling the one loosen trapezoid sail (1) is wound continuously and as desired on to a shaft which is mounted with bearings in the bottom holder (4), on the upper side it is released over a pulley (3) through which a rope (3.1) passes in a closed loop and which is at the point of fitting (3.2) via upper holder (1.1) fitted to the sail (1) and vice versa, while the rope (3.1) is elastic and is used to loosen the sail before shortening or furling, and then tighten it again (1) when the desired sail height is achieved (1).

[Claim 21] [Amended] The procedure of controlling the sail without a mast is, according to claims 1 and 2, characterized by the fact that the sail steering forces (1), due to the fitting of the sail (1) at the point of the resultant of the aerodynamic force of the wind's lift force are very small; we can simply use drivers for pivot (5), sail (1) which can be of any desired technical characteristics, optionally connected to the steering equipment or a closed loop, with an autopilot (AP) connected to the steering wheel (KR) for the purpose of vessel (P) navigation.

Description:
Compensatory sail

BACKGROUND

[0001] The invention concerns a sail without a central mast or the entire system which allows the installation of a sail without a mast to vessels or other means of transport. The subject of the invention covers the entire system including elements which replace the main central mast as the holder of the sail and the holder for transmission of forces from the mast to the vessel or other means of transport.

BRIEF SUMMARY OF THE INVENTION AND RELATED ART

[0002] The technical problem which is resolved by the invention is to provide such a construction of the sail and bearing elements so that the main central mast is redundant.

The other technical problem which is resolved by the invention is a reduced or eliminated force acting on the sail bridles, which means easier and more accurate sail control and reduction of forces acting on steering bridles and steering bridle mounts to the vessel or other means of transport.

The third technical problem which is resolved by this invention lies in the fact that the compensatory sail forms a system of sails which does not need any deck equipment and it is therefore possible to operate it with one hand and from one location. It is an extremely easy way of controlling the sail, i.e. to the extent that it can be fully automated, even by using a smartphone. In addition, in comparison to other convention sails, these sails are extremely safe, reliable, effective and with an aesthetic appeal. The sails geometry is also ideal for the purposes of so-called charter sailboat navigation or for vessels of larger dimensions. In addition, there is no need for sail replacement and therefore no need for the crew on board. Turning on the wind or close to the wind can be done extremely quickly and easily (jibing and tacking). Finally, the vessel using this system also does not heel as much as the wind-powered vessel equipped with a conventional mast.

The compensatory sail without mast is suitable for vessels of the size 5 m and several 100 m, with one to five masts. It is also possible to convert old sailing boats and install the sails on seagoing tankers. Indeed, such a system is lighter than the normal one because it does not require complex deck equipment and lower deck structural reinforcements. In addition, the mast does not penetrate the deck and lower deck saloon. By using this invention, you also obtain additional space in the saloon or cabins which accommodates the bottom part of the central mast.

Until now we have failed to observe any known solutions without a central mast.

[0003] However, there are known solutions for sails, such as for example "Junks" and the so- called "Nile cruise ships", Both cases deal with extremely old technical inventions which use completely different forms of sails to sails which are commonly known to an average inhabitant of Europe. But both listed technical solutions use the mast as the main sail holder and the main holder for transferring lift and other forces from the sail to the vessel.

Below are listed the following patents from the SIPO patent database which outline and protect technical inventions in connection with the vessel sail and which are published under the following patent application numbers, namely:

Patent application No.: 0989939

This patent deals with a sail with three light masts serving primarily for determining aerodynamic sail profile.

This patent does not address the compensatory sail without a mast and is entirely different from our invention.

Patent application No.: 22619

This patent shows a kayak with a retractable mast and sail. According to this patent, the mast can be quickly retracted, while the kayak can be used without the sail and vice versa.

This invention does not address the invention of the compensatory sail without a mast and therefore is not in any way related to our proposed invention.

Patent application No.: 22790 This invention deals with similar technical inventions to the previous one, the only difference being that it proposes similar solutions for a trimaran sailing kayak.

This invention also does not address the invention of the compensatory sail without a mast and therefore is not in any way related to our proposed invention.

Patent application No.: 9500182

This patent deals with a profiled sail. The proposed technical invention deals with the layout of aerodynamic ribs in the sail at the point of entry of the wind, which is located at the mast. It proposes wrapping the sail ribs around the mast.

This invention also does not address the invention of the compensatory sail without a mast and therefore is not in any way related to our proposed invention.

All of the above-mentioned patents represent known state of the art and do not offer technical solutions similar to our technical invention, which in essence does not use the mast for setting up the sail and transferring forces from the sail to the vessel.

DETAILED DESCRIPTION OF THE INVENTION AND BRIEF DESCRIPTION OF THE DRAWINGS

[0004] According to the proposed invention, the solution to the problem of eliminating the main mast or all masts is to set up two sail supports on each side of the mast, while the sail is clamped at the top and bottom in such a manner as to offer swivel clamping by height, and the sail fulcrum lies approximately at 1/3 of the depth of the aerodynamic profile from the start of wind incidence at the sail from the so-called incidence edge of the sail.

The present invention is outlined in the embodiment and the figures that display:

Figure 1 - shows the entire vessel P with a compensatory sail 1 without a mast in 3D view.

Figure 2 - shows the entire vessel P with a compensatory sail 1 without a mast from the stern (aft) K. Figure 3 - shows the detail A from figure 2 showing the upper sail clamp 1.

Figure 4 - shows the detail B from figure 2 showing mainly a pretensioned central part of the sail support 2.

Figure 5 - shows the side view of the entire vessel P with fully open sail 1 without a mast, where the dashed lines indicate shortening of the sail 1 which can be performed in a continuous manner and at any height. This figure also shows the two angles for setting up the sail support 1, i.e. the angle alpha 1, and the exit edge angle of the sail 1 on the vertical, i.e. the angle alpha 2.

Figure 6 - shows the detail C from figure 1 showing the lower sail support mount 2 and sail support profile cross-section 2.

The compensatory sail without a mast is installed on the vessel P and consists of the following basic elements or components: sail 1, two sail supports 2 which are installed on each side of the vessel P or sail 1, transversely to the sailing direction SP or vessel voyage direction P, upper block and tackle system 3 which is also the top fulcrum of the sail 1 and is installed approximately at 1/3 of the upper length of the aerodynamic profile of the sail 1 from the entry edge of the sail 2. V. The upper block and tackle system 3 serves to tension the sail 1 upwards together with the fulcrum of the sail 1. The block and tackle system 3 also allows continuous and custom trimming of the sail 1 and storing/rolling of the sail 1 into the bottom holder 4.

In addition, the technical assembly also consists of the bottom holder 4 which tensions the sail 1 downwards and also serves as a rolling or storage compartment of the sail 1.

The next element is the bottom fulcrum 5 of the sail 1 which is located at the bottom side of the bottom holder 4 approximately 1/3 of the lower depth of aerodynamic sail profile 1 from the entry edge of the sail 2.V and the rudder or bolt and tackle system 6 which is used to steer the sail 1.

The sail 1 has two sail supports 2 which are installed at points 2.2 at the bottom, at approximately the same length of the vessel P as the fulcrum 5 of the sail 1, while also at approximately 1/3 of the depth of the aerodynamic sail profile 1, viewed from the entry edge of the sail 2.V. At this depth of the sails 1, engages the resultant of the lift forces of the sail 1, therefore the mounting of the fulcrum 5 is exactly at this position, since we thereby reduce or eliminate forces which are necessary for holding the position of the sail 1 at different angles of the sail 1 in respect to the vessel P, in top view of the vessel P.

The sail supports 2 are at the bottom installed at the edges of the vessel, in order to provide as much space for movement of the sail 1 between sail supports 2. The sail supports 2 are secured on the vessel P via a bolt 2.S to the holder 2.N which is secured to the vessel P in various known solutions that are not subject of this invention. This mount is shown in figure 6.

The sail supports 2 are symmetrical and are mounted to the vessel P symmetrically. However, on the vertical line they are not perpendicular to the horizontal sailing line or to the vessel P, but are mounted under the alpha 1 angle directed backwards towards the stern K of the vessel P.

In addition the entry edge of the sail 2. V is designed so that its edge is displaced backwards towards the stern K of the vessel P by the alpha 2 angle which ranges between 5 to 35 angular degrees.

The alpha 1 angle is determined according to a different configuration of the vessel P and ranges between 1 to 15 angular degrees.

The alpha 1 displacement angle is determined in terms of construction so that the load on stays 2.5 and 2.5.1 is lower due to the resultant of the aerodynamic forces acting on the sail 1. The stays 2.5 and 2.5.1 transfer the aerodynamic lift force from the sail 1 or the forces from sail supports 2 to the vessel P. This angle (alpha 1 and alpha 2) and stays 2.5 and 2.5.1 are shown in the figures 1 and 5.

Due to the bending force relief on the sail supports 2, two stays 2.5.1 are mounted in addition to stays 2.5 in the direction of sailing SP which distribute forces which occur due to lift force of the sail on the two grip points on the sail supports 2 as is indicated in figures 1 and 5.

Both sail supports 2 are placed transversely on the vessel P under an angle facing each other, so that they are connected at the top of the sail 1 with a connecting coupler 3.3 to which a pulley 3 is mounted through which the sail 1 is tensioned upwards using a rope 3.1. This layout is shown in figures 2 and 3. In order to reduce wind resistance, both profiles or cross- sections P2 of the sail support 2 are designed as an aerodynamic profile along the entire length and face towards the direction of sailing SP, as shown in the figure 6.

In order to eliminate the buckling force of the sail supports 2 which occurs due to pretensioning and consequently also due to lift forces of the sail 1 acting on the sail supports 2 which could bend the sail supports 2 inwards towards the centre of the vessel P, and cause the sail supports 2 to come into contact with the sail 1 which is not favourable from the perspective of aerodynamics of the sail 1, the sail supports 2 are bent in pretension in an outward arch from the vessel P. This pretension can be achieved by setting up a crossbeam 2.9 perpendicularly on the sail support 2 in the centre lengthwise, as well as with the upper stay 2.7 and bottom stay 2.8. The stay 2.8 runs from the bottom mount of the mast support 2 to the crossbeam 2.9. However, the upper stay 2.7 runs from the upper mount of the mast support 2 to the crossbeam 2.9.

The sail support 2 is pretensioned only to the extent that the tensions in the cross-section of the sail support 2 that is under most excessive load do not exceed the values of the elasticity module of the sail support 2 holder.

All stays are made of stainless steel or dyneema braid (Kevlar fibres which are extremely light and durable). The stays 2.7 and 2.8 can also be interconnected, i.e. they represent a single stay. A clamping device is envisaged for the stays 2.7 and 2.8, which, however, is not subject of this invention, but is necessary for pretensioning the sail support 2.

The cross-beam length is defined as the product of the factor x and the length of the sail support 2.9. The factor x ranges between the values xx = 0.05 and x= 0.15.

When the sail support 2 is pretensioned it serves as an elastic clamping device of the sail 1, viewed according to the height of the sail 1. When pretensioned, both pretensioned sail supports 2 also allow absorption of small pulsating forces which are transferred from the sail 1 to the vessel P, since the sail supports 2 absorb impulses of forces distributing them over a longer time period, such as for example spring hysteresis.

The stays 2.6 and 2.6.1 have a similar purpose to the stays 2.5 and 2.5.1, but they are only strained when the sail 1 is shaking. The stays 2.6 and 2.6.1 are also required to pretension stays 2.5 and 2.5.1 which otherwise absorb the aerodynamic forces of the sail 1. Because of pretension, the stays 2.5 and 2.5.1 prevent shaking of the sail supports 2 and consequently prevent shaking or vibrating of the sail 1.

The stays 2.5 and 2.6 are mounted with a hinge to the vessel P at mounting points 2.3 and 2.4 using a custom but sufficiently strong manner to easily transfer the forces of the sail 1 to the vessel P and vice versa by shaking motion of the vessel P. The manner of securing is not a subject of this invention and can be performed in a custom way, whereby it must be designed in a such a manner to easily transfer forces generating in the hinged clamping.

The point 2.3 lies at a distance from the anchor point 2.2 multiplied by the factor X defined as (0.05 to 0.5) times the length of the sail support 2.

A similar distance applies to the distance between the mounting points 2.2 and 2.4.

The stays 2.5 and 2.6 are mounted with a hinge to mounting points on the sail supports 2 at the l/2to 3/4 height of the length of the sail support 2, viewed from the vessel P's deck upwards. The hinged clamping points are required so that the stays 2.5 and 2.6 are not bent with elastic fluctuations of the sail supports 2 in the bottom clamping, but can be swivelled by a specific angle in the hinged clamping on the deck of vessel P. The manner of securing is not a subject of this invention and can be performed in a custom way, whereby it must be designed in a such a manner to easily transfer forces generating in the hinged clamping.

In the top part, the sail 1 is clamped to the holder 1.1 into which the rope 3.1 is clamped flexibly in the clamping point 3.2, whereby the rope travels from the clamping point 3.2 via the pulley 3 towards the deck of vessel.

The clamping point 3.2 lies on the holder 1.1 at a point which may be within 1/10 to 1/2 of the length of the top depth of the aerodynamic sail profile 1.

The rope 3.1 is secured to the deck of vessel P with a rigid link allowing the lowering and lifting of the sail 1, while simultaneously pretensioning it. The manner of securing the rope 3.1 to the deck of vessel P can be custom-made and is not a subject of this invention.

The sail 1 can be of any shape. Since it is wound up/unfolded by continuous or custom trimming or rolling along the depth of its aerodynamic profile, pockets, to which profile bars 1.2 are installed, can be made in the bottom holder (boom) 4 of the sail 1 that shape the sail 1 to an aerodynamic profile.

The profile bar 1.2 can be selected by choice, whereby the greater the number the wider the bottom holder 4 has to be so we can store or fold the entire sail 1 into it including all the profile bars 1.2.

The sail 1 can be continuously shortened or lowered/rolled and vice versa using the rope 3.1. The bottom part of the sail 1 must thereby be wound up/unfolded to/from the bottom holder 4. Rolled/unrolled of the sail 1 to/from the bottom holder 4 (boom) can be performed in a custom technical manner and is not a subject of this invention.

The bottom holder 4 is mounted to the vessel P only via the fulcrum 5 which can be an ordinary rope or a special mechanism which will be detailed below.

The fulcrum 5 must in addition to aerodynamic lift forces of the sail 1 also transfer the tensioning forces of the sail 1 which is tensioned between the bottom holder 4 and the pulley 3.

The fulcrum 5 is a built-in deck or cabin element of the vessel P and links the bottom part of the bottom holder at the length from 1/10 to 1/2 of the depth of the bottom aerodynamic sail profile 1.

It is important that shortening of the sail 1 via the rope 3.1 and the simultaneous winding up of the sail 1 to the bottom holder 4 is done continuously and is carried out by relieving the sail 1 by loosening the rope 3.1 and then winding/rolling it to the shaft in the holder 4. Having reached the desired height of the sail 1, we tension the sail 1 to a desired level using the rope 3.1 which is clamped to the holder 1.1 at point 3.2.

Unrolling the sail 1 is performed in a reverse order to the winding.

We can improve the aerodynamics of the sail 1 by always keeping the sail 1 taut because the cross-sections of the sail, viewed according to the height of the sail 1 are similar or, in the case that the sail 1 is sufficiently tensioned or straight, have the same incidence angles of the air stream which travels through the sail 1.

Control of the sail 1 is performed using a rope with a bolt and tackle system 6 which is connected to the vessel P and bottom holder 4.

Because the sail 1 is clamped at approximately 1/3 of the depth of the sail profile 1, viewed from the entry edge 2.V of the sail 1, the sail 1 functions similarly to the compensatory rudder of aircraft devices during motions from the axis between point 3.2 and the fulcrum 5.

Aerodynamic lift force of the sail 1 is approximately at 1/3 of the length of the central aerodynamic sail profile 1. Because the top part of the sail 1 is clamped to the holder 1.1 at point 3.2 at approximately 1/3 of the depth of the top aerodynamic sail profile 1, while in the fulcrum 5 it is clamped at approximately 1/3 of the depth of the bottom aerodynamic sail profile 1, and with regard to the fact that the exit edge 2.1 of the sail 1 and entry edge 2.V of the sail 1 form a geometrical figure which is linearly narrowed from the bottom up or from the fulcrum 5 towards the top or point 3.2, we summarise that the aerodynamic point of application of the lift force of the sail 1, intermediate profiles of the sail 1 are constantly at approximately 1/3 of the depth of the aerodynamic profile of individual cross-section of the sail 1, viewed from the entry edge 2 V towards the exit edge 2.1.

The upward narrowing of the sail 1 is also a consequence of a non-vertical entry edge 2.V of the sail 1 which is inclined backwards towards the stern K of the vessel P by the alpha 2 angle which ranges from 5 to 35 angular degrees.

Because the clamping of the sail 1 is constructed in such a manner, control of the sail 1 requires only minimal force. When the sail 1 is placed windward under a desired angle to provide optimum lift force, the controlling and holding force of the sail 1, which is transferred to the sail 1 via the rope with the bolt and tackle system 6, is almost null.

Because the aerodynamic point of application of the lift force of the sail 1 according to the wind flow through the sail 1 according to the longitudinal tautness of the sail 1 and other factors moves around a virtual line segment running between the point 3.2 and the bottom fulcrum 5 which lies at approximately 1/3 of the depth of the aerodynamic sail profile 1 from the entry edge 2.V towards the exit edge 2.1, we select a slightly shorter distance of the sail fulcrum than 1/3 of the depth of the aerodynamic sail profile 1 so that the rope with bolt and tackle system 6 always provides positive tensile forces which are caused by the lift force of the sail 1.

In case the fulcrum of the sail 1 would selected at a greater depth of the aerodynamic sail 1 profile such as the virtual line running between the point 3.2 and the fulcrum 5, negative forces could be achieved on the rope with the bolt and tackle system 6, whereby controlling of the sail 1 that would be clamped in this manner would be very difficult or unstable. The fulcrum 5 can be designed as an ordinary rope tensioned between the vessel P and bottom holder 4, or it can be designed as a shaft which is connected to the autopilot AP of the vessel P via the gearbox with electrical motor. The fulcrum 5 gearbox can be controlled in all possible ways of the known state of the art, and therefore is not a subject of this invention.

The subject of this invention is the proposed steering connection of the fulcrum 5 gearbox with the autopilot AP of the vessel P and the helm KR of the vessel P.

Since both the autopilot AP and the helm KR of the vessel P represent known state of the art, they will not be outlined as they do not concern the subject of invention, i.e. the steering connection with the fulcrum 5.

If we compare the known state of the art of the sail 1 controlling technique with the proposed invention of controlling the sail, we find that the forces necessary for rotating the sail around its vertical axis are in the case of the known state of the art are very large because they transfer the moment caused by the aerodynamic force of the sail 1 around the fulcrum which is in this case of the known state of the art, the mast. The moment of force around the mast is in this case (in the case of the known state of the art) the product of the aerodynamic lift force of the sail 1 multiplied by 1/3 of the depth of the central aerodynamic profile of the sail 1.

In our case the moment between the fulcrum 5 and the pulley 3 around the fulcrum axis is null or negligible.

For this purpose, the mechanical assembly which is dimensioned for relatively small moments, can be used to control the sail 1 through the fulcrum 5 and the bottom holder 4. Such a mechanical assembly can be a gearbox with an electric motor.

Since in the proposed invention the forces for controlling the sail 1 are very small, the computer connection for controlling rotation of the sail 1 and rudder of the vessel P can be used, which through the autopilot AP steers the helm KR of the vessel and rotation of the sail 1 around the axis with the fulcrum 5 and the pulley 3 according to the desired course SP, wind direction and power.

This connection can be performed as one-sided design - i.e. as steering or as a continuous loop controller which constantly passes information to the computer which modifies helm KR angles and rotation angles of the fulcrum 5 of the sail 1 accordingly, with the aim to keep the vessel P on the desired course or direction of sailing SP.