AU2010345702B2

AU2010345702B2 - Mast for sailing vehicles

Info

Publication number: AU2010345702B2
Application number: AU2010345702A
Authority: AU
Inventors: Stefan Vintera
Original assignee: Individual
Current assignee: Individual
Priority date: 2010-02-15
Filing date: 2010-02-15
Publication date: 2015-10-15
Anticipated expiration: 2030-02-15
Also published as: AU2010345702A1; CN102762443A; NZ602340A; CA2789767A1; EP2536618A1; US20120304907A1; WO2011097657A1; JP2013519575A

Abstract

The invention relates to a mast for sailing vehicles, said mast being divided in a lateral direction into two mirror symmetrical mast profiles (mast halves) (1) which merge at or under the top of the mast, which are placed apart on the base of the mast, and which curve outward forming arcs or run in a straight manner. Acting forces are transferred via an inner stay (2) and inner spokes (3), by means of the arrangement and number of which the dimensional stability of the construction and of the static advantage thereof is achieved. A direct flow onto the mainsail (10) is enabled by the division of the mast into two profiles, the design of the mast halves and the profile shape thereof (8), (9) being preferably carried out in an aerodynamic manner.

Description

1 Mast for Sailing Vehicles Background The present invention relates to a mast for dinghies, sailing ships and sailing vehicles of any type, which consist of two mast halves placed laterally apart and transversely to the longitudinal axis which are outwardly curved, arched or run straight, and merge at or under the top of the mast and reach the largest structural width so that the stay deployed centrally between the mast halves or the luff of the sail creates a vertical tension and the spokes deployed transversely between the mast halves support the transverse forces, wherein dimensional stability of this construction and statistical advantage is achieved with their arrangement and number. The design of the mast profile is provided preferably with an aerodynamic form in a known manner. With the usual mast design form, the bending moment generated by the lateral wind pressure on the mast is absorbed by a shroud bracing outwardly spread by (several) spreaders and the resulting forces are introduced through the shroud into the hull of the boat on the windward side. Both the spreaders and the mast absorb the load created by the wind forces and the prestressing forces on the rigging and the stays. For aerodynamic and weight reasons, the mast and the spreaders should be maintained as slender or thin as possible. However, in order to avoid buckling, the technical thinness of the design is limited, so that the mast is in the usual construction form provided with a wide profile and a high weight for resistance to buckling, and by being placed in front of the sail, it is held with the luff in a mast rail, which has a negative influence on the incoming flow of the wind relative to the course of the boat on the wind. When airflow enters the sail, the flow is cut off and vortices are generated on the air side and on the downwind side in the area behind the mast. The flow-related technical problem is known and attempts were made to solve it in various manners. This problem is solved in WO 1988/003889 by an arrangement of additional profiles or a pair of special vanes arranged next to the mast, wherein this solution of the problem deals with the disadvantage of additional load, which increases the heeling moment.

2 In patents FR 1524 392 A, US 3 724 412 A, GB 1399 421 A and FR 2 751 609 A1, the static advantage is disregarded and a higher weight or a smaller bending resistance of the construction are considered acceptable. It is therefore desirable to improve the statics through the design of a mast in the manner described above, while positive flow characteristics are also taken into account. Object of the Invention It is the object of the present invention to overcome or ameliorate one or more disadvantages of the prior art. Summary of the Invention The present invention provides a mast for a sailing vehicle, wherein a division of the mast in a lateral direction results in two mirror-image mast halves, which merge at a top of the mast and are disposed apart from one another at a mast base, forming the mast halves, wherein a transfer of acting forces takes place through an inner central stay and inner spokes, wherein the inner central stay is provided with a guide rail for accommodation of a mast slider of the luff, and wherein the inner central stay, as seen in a side view of the mast, extends abaft from the top of the mast. With the mast design according to the present invention, the forces resulting from the wind pressure and from prestressing are transmitted through the arc shape or through the straight design of the mast halves in the form of pressure forces, and in the form of traction forces through spokes and through a centrally deployed stay. Due to the ratios between the forces on which the construction of the invention is based, a ratio to the number of the employed spokes and to the frequency of subdividing is created for both mast halves which significantly reduces the propensity of the mast halves to buckling, which in turn results in a significantly thinner design of the two profile halves of the mast.

3 The resistance torque of the mast perpendicular to the wind direction must be considered to be significantly higher due to the width of the construction with the construction design according to the invention. Moreover, the static advantage of the construction according to the invention is the result of the significantly more resilient spokes relative to their thin design which is exposed to the tensile forces, as well as based on the abundance of the arrangement of the spokes, or on a better distribution of the forces throughout the entire length of the mast halves. The construction in accordance with the invention thus results in a higher stability of the mast relative to its weight. In one variant of the construction according to the invention, the mast halves run straight or partially straight, and the tendency to buckling in a certain direction is due in this case to the asymmetric (inner) material stresses related to the profile, in each case in the direction of the convex side of the (open, semi-circular) profile of the mast halves, wherein buckling can be avoided with an appropriate arrangement of the spokes or of the pressure elements, in relation to their frequency. Direct air flow to the sail is thus made possible because of the arrangement of the sail centrally between the mast halves. The resulting aerodynamic advantage is obtained from the direct airflow to the sail, as described in a similar form in patents FR 1 524 392 A, US 3 724 412 A, GB 1 399 421 A and FR 2 751 609 A. In addition, the more slender design of both profile halves of the mast also makes it possible to attain a corresponding execution of the vane profiles which is more streamlined, so that a better airflow can be achieved to the main sail with the course on the wind. The airflow can be further improved when the construction is realized as a rotatable construction.

4 The spokes deployed on the inner side do not result thanks to the small, round or flat elliptical profile in any significant vortexes or air resistance values. The sail can be raised on the central stay, or with lighter forms (small dinghies) hooked into the spokes along the length of the luff of the sail, but it can be also freely extended between the mast and the mast base (construction without a central stay). The introduction of the lateral wind forces in the hull of the boat takes place either directly via the mast base mounted on the deck, or additionally also through the shrouds, which can act in its turn deep at the height of center of gravity at the inner stay the sail, resulting in a further weight loss of the entire rigging and in a not insignificant lowering of the center of gravity of the mast and of the rigging. Furthermore, control over Genoa sail is facilitated with the more slender construction form of the spread mast and the deeper deployment of the spreaders. As shown in the diagram of Fig. 1, a boat is indicated in front view, which comprises the construction form of the mast according to the invention provided with two mast halves 1 and with the inner stay 2, which is connected through frictional force with the arc ends (4) and with the mast base 5, and which tensions the curved mast halves vertically in the longitudinal axis. The spokes 3 provide for the bracing of the mast halves to each other, transversely and obliquely to the longitudinal axis. Optional shrouds 6 additionally conduct the generated forces into the boat body 7. Fig. 2 and Fig. 3 represent the profile forms 8 and 9 of the mast halves in a cross section normal to the longitudinal axis of the mast.

Claims

1. A mast for a sailing vehicle, wherein a division of the mast in a lateral direction results in two mirror-image mast halves, which merge at a top of the mast and are disposed apart from one another at a mast base, forming the mast halves, wherein a transfer of acting forces takes place through an inner central stay and inner spokes, wherein the inner central stay is provided with a guide rail for accommodation of a mast slider of the luff, and wherein the inner central stay, as seen in a side view of the mast, extends abaft from the top of the mast.

2. The mast according to claim 1, wherein a design and an arrangement of the mast halves and its profile form is carried out in a streamlined form.

3. The mast according to claim 1, wherein the mast halves are in each case provided with a straight or a partially straight design, and wherein they merge inclined to each other at the top of the mast or below the top of the mast.

4. The mast according to claim 1, wherein a strip of canvas is mounted in order to improve wind guidance and to enlarge a sail area, respectively, on rear edges throughout an entire length of the mast halves.

5. The mast according to claim 1, wherein adjustable guide profiles are mounted in order to improve wind guidance throughout an entire length of the mast halves.

6. The mast according to claim 1, wherein a profile of the mast halves is designed in a streamlined and high-strength form as a strutted hollow profile.

7. The mast according to claim 1, wherein a design of the mast halves is realized by an aluminum extruded profile or by carbon materials and laminates.

8. The mast according to claim 1, wherein a design is realized by laminates in a composite construction. 6

9. The mast according to claim 1, wherein a design of spokes is realized in as a round profile, with wire or rope articles as a streamlined flat material manufactured from steel carbon materials/laminates or from plastic materials.

10. Sailing vehicle having a mast according to any of claims 1 to 9.

11. The sailing vehicle according to claim 10, wherein the mast is mounted in a fixed manner on a boat body and wherein resulting forces are introduced directly through a mast base into a hull.

12. The sailing vehicle according to claim 10, wherein the mast is mounted rotatably and/or pivotably.

13. The sailing vehicle according to claim 10, wherein, when the mast is rotatably and/or pivotably arranged on the sailing vehicle, a beam is firmly connected to the mast and swivels during a rotation.

14. Mast for a sailing vehicle, the mast being substantially as hereinbefore described with reference to the accompanying drawings. Stefan Vintera Patent Attorneys for the Applicant/Nominated Person SPRUSON & FERGUSON