MAST CONSTRUCTION FOR A SAILING VESSEL

DESCRIPTION The invention relates to a mast construction for placement on the hull of a sailing vessel and the like, which mast construction comprises a mast provided with a mast foot and a mast top, which mast can be positioned with respect to the hull of the sailing vessel using a rigging that engages the mast.

Generally the mast and the hull of vessels are fixedly connected to each other. A drawback of such a fixed mast is that such a sailing vessel sails less effectively as the wind becomes stronger. The fact is that the sailing efficiency of a sailing vessel with a fixed mast (viz. the conversion of wind energy into sailing speed) decreases inversely proportionally to the wind speed.

This is caused by the fact that the fixed mast starts to tilt sideways and downwards as the wind becomes stronger, as a result of which the effective sail surface decreases. It should be considered in that connection that the wind is strongest at the top of the mast, and that the sails catch this wind less effectively as a result of said tilting of the mast.

In addition to that, the hull of the sailing vessel is forced deeper and deeper into the water as a result of the tilting of the mast that occurs when the wind velocity increases, causing the sailing resistance to increase. Other disadvantageous sailing characteristics concern the fact that the sailing vessel will increasingly drift leeward in the case of an increasing wind velocity due to the increasing slope of the lateral hull surface. Furthermore, also the rudder blades will take up an increasingly sloping position in the water, which has an adverse effect on the navigability of the sailing vessel.

The object of the invention is to obviate the above drawbacks and to provide a mast construction as referred to in the introduction, which does not have these drawbacks. According to the invention, the mast construction is characterised in that the mast foot is movable relative to a pivoting point formed by the point of engagement of the rigging to the mast.

This construction achieves that the mast will no longer tilt sideways and downwards, so that the forces exerted on the mast construction by the wind will have a different effect on the vessel, resulting in improved sailing characteristics.

This construction causes the mast and the sailing vessel to be lifted up in the water, resulting in a reduced drag. In addition to that, this keeps the hull flatter in the water, thereby reducing the disadvantageous effects of the aforesaid leeward drifting and increasing the efficiency (the conversion of wind energy into sailing speed). More specifically, the mast foot is connected to a first end of a pivoted spar, which pivoted spar is pivotally connected to the hull of the vessel with its other end. In this embodiment, said other end of the pivoted spar is furthermore connected to the hull via an arm that extends vertically below the deck of the vessel.

At least the end of the arm that extends towards the water surface may include an angle with the vertical, so that the mast foot, and thus the sail, can move outwards and upwards relative to the hull, thereby optimising the balance of the vessel and the lateral pressure point of the sail.

Since the lateral pressure point is located below the point where the rigging engages the mast, the sail will be automatically tilted from below by the wind, which has a lifting effect on the sail.

It has been found that an effective angle is an angle between 15° and 30°, the angle should in particular be about 20°.

A specific embodiment is furthermore characterised in that the pivoting point is in line with the arm. The invention further relates to a sailing vessel provided with a mast construction according to the invention, which sailing vessel may in particular be a catamaran.

The invention will now be explained in more detail with reference to a drawing, in which: Figures 1a-1c and 2a-2b show various views of a first embodiment of a sailing vessel provided with a mast construction according to the invention.

For a better understanding of the invention, like parts will be indicated by the same numerals in the description of the figures. In figures 1a-1c, numeral 10 indicates a sailing vessel, in particular a catamaran, which is provided with a mast construction according to the invention. The sailing vessel 10 comprises two hull parts 11a-11 b, which are connected by means of a tubular construction 12a- 12b. Said tubular construction or spar construction 12a-12b is furthermore provided with a wing shaped spar construction 13a-13b, which is used by the crew of the catamaran.

Rigging 18a-18b-18c-18d is used for positioning the mast 14 with respect to the hulls 11a-11b of the sailing vessel. Said rigging 18a-18d is also referred to by the nautical term "stays". In addition to the tubular construction 12a-

12b, a so-called spreader tube 19 is used for positioning the two hull parts 11a-11 b relative to each other.

The mast 14 is used for rigging the mainsail 16, which is set by means of the boom 15. In addition to that the sailing vessel may be provided with a jib 17, which can be set with respect to the hull 11 a-11 b by means of the spar 23.

According to the invention, the mast 14 and in particular the mast foot 14a are movable relative to a pivoting point formed by the point of engagement of the rigging 18a-18b-18c-18d on the mast 14. Said point of engagement is indicated at 20 in figures 1a-1c.

Furthermore, the mast 14 is attached to a first end 21a of a pivoted spar 21 via the mast foot 14a, which pivoted spar 21 is pivotally connected to the hull of the sailing vessel 10 with its other end 21 b.

This construction achieves that the mast 14 will no longer tilt sideways and downwards, so that the forces exerted on the mast construction by the wind will have a different effect on the vessel 10. This leads to improved sailing characteristics. As a result of this construction the mast 14 and the sailing vessel 10 are lifted up in the water, resulting in a reduced drag. In addition to that, this will keep the hull 11 a-11b flatter in the water, so that the disadvantageous effects of the aforesaid leeward drifting will occur to a lesser extent.

As shown in figures 1a-1c, and in particular in figures 2a-2b, the other end of the pivoted spar 21 is connected to an arm 22 that extends under the deck of the vessel 10 that is formed by the spar construction 12a-12b. Said arm 22 is pivotally connected to the other end 21 b of the pivoted spar 21 with a first end 22a and to the spar construction 12a or the hull of the vessel with the other end 22b.

In this case, too - as shown in figures 2a and 2b - the first end 22a of the arm 22 that extends vertically below the deck of the vessel 10 is set up between the hull parts 11 a-11b by means of additional rigging 24a-24d. Thus, the forces that are exerted on the mainsail 16, the mast 14 and the pivoted spar 21 while sailing can be effectively diverted to the hull 11 a-11b via the arm 22. Said arm 22 is also referred to by the nautical term "dolphin striker".

As a result of this construction, the pivoted spar 21 and the mast

foot 14a, and thus the sail 16, can move outwards and upwards with respect to the hull 11a-11 b, thereby optimising the balance of the vessel 10 and the lateral pressure point of the sail 16. The pivoted spar 21 is set up between the hull parts 11a-11 b by means of the rigging 25, which is connected to the tube 12a with its one end 25a and to the pivoted spar 21 with its other end 25b, so as to divert the forces in an effective manner.

The sailing characteristics are improved in that (see figures 2a-2b) the end 22a of the arm 22 that extends towards the water surface includes an angle with the vertical. In figures 2a and 2b this is indicated by numeral 22c, which represents the transition point between the vertical arm 22 and the arm end 22a that extends at an angle thereto. The enables the mast foot, and thus the sail, to move outwards and upwards relative to the hull 11a-11 b, thereby optimising the balance of the sailing vessel 10 and the lateral pressure point of the sail 16. The angle may be about 20°. The sailing characteristics of the vessel are furthermore significantly optimised, if not improved, in that the fixed pivoting point 20 about which the sail 16 and the pivoted spar 21 pivot is in line with the inclined arm end 22a. This is represented in figure 2a by the imaginary axis 26, which extends to the pivoting point 20 in figures 1a-1 c, in line with the arm end 22a. Also the rigging end 25a that sets up the pivoted spar 21 lies on the imaginary axis 26.

Said axis 26 is thus formed by the point of engagement 20 and the pivoting point 21 b of the pivoted spar 21 of the hull 11 a-11 b. In a first embodiment, said imaginary axis 26 may have a vertical orientation, with the point of engagement 20 being located directly above the pivoting point 21 b of the pivoted spar 21. In a preferred embodiment, the axis 26 may include an angle with the vertical. Said angle is created by the inclined arm end 22a of the "dolphin striker" 22, via which arm end 22a the pivoted spar 21 is connected to the hull 11 a-11 b. The angle α of the axis 26 may range between 15° and 30°, more particularly it may be about 20°.

The mast food 14a will move sideways both in the case of a vertical imaginary axis 26 and in the case of an inclined imaginary axis 26, whilst in the latter embodiment the mast foot 14a will also move upwards.