Patent application title: MAST FOR SAILING VEHICLES
Stefan Vintera (Wien, AT)
IPC8 Class: AB63B1500FI
Class name: Ships watercraft with means used in providing sailpower having specific mast mounting means
Publication date: 2012-12-06
Patent application number: 20120304907
Described is a mast for sailing vehicles 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 are curved outward to form arcs or run in
a straight manner, wherein the acting forces are transferred via an inner
stay (2) and inner spokes (3), so that the stability of the construction
is achieved with their arrangement and number and static advantage is
achieved. A direct flow onto the mainsail (10) is enabled by the division
of the mast into two profiles, wherein the design of the mast halves and
the profile shape thereof (8), (9) are preferably carried out in an
1. Mast for a sailing vehicle, characterized in that a division of the
mast in a lateral direction results in two mirror-image mast halves,
which merge at a mast top and are apart from one another at a mast base,
forming curved or straight mast halves (1), and the transfer of acting
forces takes place through an inner stay (2) and inner spokes (3).
2. The mast according to claim 1, characterized in that 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, characterized in that the mast halves are in each case provided with a straight or a partially straight design, and that they merge inclined to each other at the mast top or below the mast top.
4. The mast according to claim 1, characterized in that instead of the stay (2), the luff of the main sail transfers vertical tension with a simpler construction.
5. The mast according to claim 1, characterized in that the central stay is provided with a guide rail for accommodation of the mast slider (of the luff).
6. The mast according to claim 1, characterized in that the profile (8) of the mast halves is maintained open for a light design and provided with a light material or sail canvas inside a covering (11). (FIG. 2)
7. The mast according to claim 1, characterized in that each (open) profile of the mast halves faces with its concave side outward, and that the mast halves are supported and connected to each other by pressure elements.
8. The mast according to claim 1, characterized in that 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.
9. The mast according to claim 1, characterized in that adjustable guide profiles are mounted in order to improve wind guidance throughout an entire length of the mast halves.
10. The mast according to claim 1, characterized in that a profile (9) of the mast halves is designed in a streamlined and high-strength form as a strutted hollow profile.
11. The mast according to claim 1, characterized in that the mast is mounted in a fixed manner on a boat body and that resulting forces are introduced directly through a mast base (5) into a hull.
12. The mast according to claim 1, characterized in that the mast is mounted rotatably.
13. The mast according to claim 1, characterized in that the mast is mounted pivotably.
14. The mast according to claim 1, characterized in that the mast is mounted rotatably and pivotably.
15. The mast according to claim 1, characterized in that when a rotatable (and pivotable) execution is used, the beam is firmly connected to a mast construction and it swivels during a rotation.
16. The mast according to claim 1, characterized in that a design of the mast halves is realized by an aluminum extruded profile or by carbon materials and laminates.
17. The mast according to claim 1, characterized in that a design is realized by (plastic/carbon) laminates in a composite construction.
18. The mast according to claim 1, characterized in that a design of spokes is realized in a simple construction as a round profile, with wire or rope articles having an optimal construction as a streamlined flat material manufactured from steel carbon materials/laminates or from plastic materials.
19. The mast according to claim 1, characterized in that pressure elements are additionally attached to spokes between the mast halves for high and varying loads.
 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/03889 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.
 In patents FR 1 524 392 A, U.S. Pat. No. 3,724,412 A, GB 1 399 421 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.
 The object of the invention is therefore to improve the statics through the design of a mast in the manner described above, while positive flow characteristics are also taken into account.
 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.
 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.
 In contrast to Utility Model G 92 07 461.8, the bifurcation of the mast is not used based on the present concept to increase the sail area by implementing the beam through the sail, but instead it is used to increase the stability of the mast itself. The present construction thus enables static redirection very effectively, even with extremely high wind pressures.
 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, U.S. Pat. No. 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.
 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.