Windsurf board comprising a sail pivotable in a horizontal or vertical position

Abstract

 There is provided a windsurf table, provided with a conventional type of sail, or a wing shaped sail, operating with the sail surface of lying parallel to the water surface. To this end the shaft is provided with a double articulated joint, one arranged at the lower end and coupled to the table body and the other arranged at the top end and coupled to the sail. There are further provided means adapted for transforming the windsurf table into a conventional type of table and means for operating the sail in a horizontal and/or in a vertical plane.

Description

[0001] The present invention relates generally to winsurf tables and,more specifically,to a new type of winsurf table the sail of which is used both in a parallel position to the water surface and in a perpendicular position to said water surface.

[0002] As is known, the conventional configuration of the winsurf tables provides that the sail be inserted into a shaft having a single articulatad joint at the base or bottom thereof,coupled to the table body. Thus this joint causes the sail to lie mainly in a vertical plane with respect to the water surface, while allowing for the possibility of tilting the sail in a strong wind condition.

[0003] However,the sail can be tilted with maximum angles of about 30° and, under these conditions,the sail efficiency and the table speed decrease.

[0004] If the sail is tilted with greater angles to cause it to approach a horizontal position,then, in addition to an efficiency decrease,the risk will occur of a possible falling into water of the operator.

[0005] For increasing the sail efficiency it is conventional to use them on a parallel plane to the water surface,thereby increasing the table efficiency because of aerodynamic and hydrodinamic reasons.

[0006] On the other hand a sail of this type may be coupled with difficulties to the table body since this coupling must assure a great control capability of the table ana facility of displacement of the sail with respect to the table with a little force requirement by the operator.

[0007] The task of the present invention is to overcome the above mentioned drawbacks,that is efficiency decrease of a conventional sail and coupling difficulties in the coupling of the sail to the table body,by providing a new type or winsurf table with a high sail efficiency and a higher speed.

[0008] More specifically,the windsurf table according to the present invention is characterized in that it is provided with either a conventional or a wing shaped sail arranged with the sail surface parallel to the water surface and a rigid shaft having a double articulated joint,one arranged at the lower end and coupled to the table body ana the other arranged at the top end and coupled to the sail shaft,means being further provided for manoeuvring the sail in the horizontal plane.

[0009] According to a feature of the present invention,there are moreover provided means for operating the winsurf table as a conventional table and means for operating the sail also in a vertical plane.

[0010] The invention will be described in a more detailed way hereinafter with reference to preferred embodiments thereof,given esclusively by way of indicative examples and illustrated in the accompanying drawings,where:

figure 1 illustrates a top view of the winsurf table according to the present invention;

figure 2 is a side view of the winsurf table or figure 1 in which has been represented by a dashed line the position of the sail in the vertical plane for illustrating the possibility of using the winsurf table according to the invention as a conventional type of winsurf table;

figures 3a and 3b illustrate perspective views of a possible position of the sail on a conventional winsurf table respectively in a weak wind condition and strong wind condition;

figures 4a and 4b are perspective views illustrating the windsurf table according to the present invention under the conditions of figures 3a and 3b;

figures 5a and 5b are perspective views of the winsurf table embodiment in which the sail may be used both in the vertical and horizontal position;

figure 6 is a perspective view illustrating the embodiment of the present invention in which the sail may be used esclusively in the horizontal position;

figure 7 illustrates a diagram of the improved performance, the table being the same,of the sail according to the present invention (A) with respect to a conventional sail (B);

figures ba and 8b are perspective views illustrating the details of the bearing structure or the horizontal and vertical sail embodiment of the present invention and respectively the horizontal sail embodiment thereof;

figures 9a and 9b schematically illustrate the embodiment of the present invention having a double articulated joint shaft respectively of the cardanic and resilient type

figure 10 illustrates the detail of a possible shaft assembly in the embodiment in which the sail may be used either horizontally and vertically; and

figures lla-d schematically illustrate cross-sectional views of some possible embodiments of the sails.

Figures 1 and 2 illustrate the sail windsurf table according to the invention.

[0011] More specifically the table body 1 is provided with a shaft 2( which will be called herein secondary shaft ) including a lower articulated joint 3 coupled to the table body 1 and a top articulated joint 4 coupled,in this case,to the boom 5.At the end of the boom near the articulated joint 4 there is affixed the shaft 6 of the sail wrich, in this case,is the main shaft thereto there is coupled the sail 7,either of conventional type or having a wing shape and whichin figure l,is horizontally arranged while in figure 2 it is shown in a vertical position by the dashed line.

[0012] Figure 3a shows a conventional windsurf table provided with a table body 1 with a shaft 2 coupled in an articulated way to the table body by means of a cardanic or resilient articulated joint 3 with boom 5 and a triangular sail 7 in the attitude assumed under a weak wind condition,while figure 3b illustrates that same conventional winsurf table in the attitude assumed under strong wind conditions.

[0013] Figures 4a and 4b illustrate the winsurf table according to the present invention including a table body l,the shaft 2 coupled to the table body 1 through the articulated joint 3 and the boom 5 coupled in an articulated way at 4 to the top end of the shaft.The boom forms the shaft of the sail 6 and includes rod members 8 affixed to the two sides of the boom and to the shaft of the sail 6 and used for manoeuvring the sail in a horizontal position.The sail 6 may be or conventional design or of wing shape,its specific profile being illustrated hereinafter.In figure 4a the windsurf table according to the present invention is shown in the attitude assumed under a weak wind condition and in figure 4b the table is shown in the attitude assuled under a strong wind condition.

[0014] Figures 5a and 5b show the windsurf table according to the present invention in the embodiment thereof in which it may be transformed from vertical sail to horizontal sail as a conventional type of windsurf table.In this case, figure 5a shows that,in order to transform the windsurf table with horizontal sail 6 into a vertical sail table,it will be sufficient to rotate the sail shaft through 90° and then affix,by any suitable affixing means 9, the lower end of the shaft of the sail 6 to the secondary shaft 2.

[0015] Figure 6 illustrates the embodiment of the windsurf table according to the present invention in which the sail may be used only horizontally. In this case at the top end of the secondary shaft 2 there is articulated, through the cardanic or resilient articulated joint 4,a shaft 10 thereto the boom 5 is coupled and which centrally supports the sail 7 having in this case a substantially triangular shape.There are also shown herein the table body 1, the lower articulated joint 3 of the secondary shaft 2,the sail 6 shaft and the rod members 8.In this embodiment of the present invention it is possible to provide a greater extension of the sail (ratio of the square of the length of the shaft 6 and sail surface) thereby further increasing the sail efficiency.

[0016] From the figures it should be apparent the differences or the two sail types under the same regatta conditions,which provide an aerodynamic improvement due to the fact that the horizontal sail is not affected by the wind free layer at the water surface, thereby an even angle of the sail all along its extension is outaineu.

[0017] A further advantage of hydrodinamic type is due to the fact that the horizontal sail, by providing a greater component of the aerodynamic force tending to lift the table,causes a decrease of the table wet surface, thereby reducing the advancing resistance.

[0018] Thus,the windsurf table according to the present invention will be used,in principle,as a conventional windsurf table with conventional manoeuvring operations,that is by displacing the sail with respect to the table and displacing the sail center with respect to the drift center.

[0019] Figure '( illustrates a diagram in which there is shown the performance, the table being the same,of the sail according to the present invention indicated by the curve A and the conventional sail indicated by the curve B;the arrow Fl shows the wind direction and the radial numbers indicate the attitude of the windsurf table in decrees.

[0020] From this diagram it should be easily apparent that the windsurf table according to the present invention (curve A) provides an efficiency improvement with a higher speed than in the conventional windsurf table (curve B) and that this embodiment of the tinvention(horizontal sail and double articulated joint shaft) affords the possibility of manoeuvring the table in a very easy way.

[0021] The manoeuvring operations are facilitated owing to the provision of a specifically designed boom having a plurality of gripping zones or points.

[0022] Figure 8a illustrates such a structure in which the boom 5 is coupled to the table body 1 by means of the secondary shaft 2 and is provided with the two pairs of rod members 8,8' which are applied at one side to the sail shaft 6 and at the other side at an intermediate point of the boom 5.The sail 7 is hoisted to the sail shaft 6 and extends through the boom 5 and the rod pairs 8,8'.In figure 8a the boom is shown with the sail 7 in a vertical position and refers to the embodiment of the windsurf table in which the table may be transformed into a horizontal sail table,while figure 8b shows the embodiment with exclusively horizontal sail.

[0023] Figure 9a illustrates the shaft 2 which is coupled to the table body 1 through a cardanic articulated joint 3,while the sail shaft 6,or the boom 5,depending on the case,is coupled to the top ena of the shaft 2 also through a cardanic articulated joint 4.

[0024] Figure 9b shows articulated joints consisting of a resilient material block(rubber or the like material).

[0025] These members made of a resilient material provide tension and compression resistance and afford an optimal transfer of the loads from the sail to the table body.

[0026] The manoeuvrability is assured by the two articulated joints 3 and 4 arranged at the ends of the shaft 2 and coupled,as aforesaid,one to the table body 1 and the other to the sail shaft 6 or the boom 5, which joints afford the possibility of orienting the sail in any directions.

[0027] The present invention further provides a device permitting to transform the horizontal sail embodiment of the present invention into the conventional vertical sail windsfurf table. This device has been indicated in figure 10 by the reference 10 and comprises a bracket 11 acting as a stop member provided with a side slot 12 therewithin a stop pin 13 is arranged affixed to the secondary shaft 2,said bracket 11 encompassing both the secondary shaft 2 and the shaft 6 of the sail so as to lock it in the vertical position in the embodiment with vertical sail.By removing the pin 13,the bracket 11 can be lowered to the position represented by the dashed line,thereby disengaging the shaft 6 of the sail which may be rotated to the horizontal position at the top articulated joint 4 for the embodiment with horizontal sail.

[0028] Figure 11 shows different embodiments of the sail inserted,in a conventional way,onto a tubular bearing structure (shaft 6 of the sail) (figure lla) or inserted onto a shaft having a wing shape with single sheet sail (figure llb) or a double sheet sail (figure llc) or of the wing shape rigid or semirigid type (figure lld).

[0029] From the above disclosure it should be apparent that a winsurf table has been provided having a horizontal sail and a coupling with the windsurf table made by using a double articulated joint shaft,with the lower articulated joint being coupled to the table body and the top articulated joint to the sail.The sail,coupled to the windsurf table by means of the double articulated joint shaft,may be used both in the horizontal and in the vertical position so as to employ a double boom,or only in the orizontal position in which case a simple boom is used.

[0030] While the invention has been disclosed and illustrated with reference to preferred embodiments thereof,it should be apparent to those skilled in the art that several modifications and variations can be carried out coming within the invention scope consisting of having provided a new type of windsurf table of high performance and easily operable by using the sail in a horizontal position owing to the provision of the two articulated joint shaft system,with or without locking of the secondary shaft.

Claims

1- A windsurf table,characterized in that it is provided with a conventional type of sail or a wing shaped sail arranged with the sail surface parallel to the water surface and a rigid shaft provided with a double articulated joint,one at the lower end coupled to the table body and the other at the top end coupled to a shaft of the sail,means being further provided for operating the sail in a horizontal plane.

2- A windsurf table according to claim 1,characterized in that there are moreover provided means adapted for using the winsurf table as a conventional table and means for operating the table sail also in the vertical plane.

3- A windausf table according to claims 1 and 2, characterized in that to the top articulated joint of the shaft there is coupled the boom which in turn supports the sail shaft.

4- A windsurf table according to claim l,characterized in that the means for operating the sail in the horizontal plane consist of rod members affixed on a side to the shaft of the sail and on the other to the boom or a shaft coupled to the top articulated joint.

5- A windsurf table according to claim 2,characterized in that the means for using the winsurf table as a conventional windsurf table,consist of a coupling between the shaft of the sail and the shaft of the windsurf table at the lower end of the two shafts and the conventional boom.

6- A windsurf table according to claim 2,characterized in that the means for operating the sail also in the vertical plane consist of two pairs of rod members respectively coupled to the shaft of the sail and the two sides of the boom.

7- A windsurf table according to claim 5,characterized in that the coupling between the shaft of the windsurf table and the shaft of the sail consists of a bracket,a fork member,a pin or a simple rope.

8- A windsurf table according to the preceding claims,characterized in that the shaft coupling the sail and the table body has a round,elliptic,shaped, either solid or hollow cross-section.

9- A windsurf table according to the preceding claims,characterized in that the articulated joints are either of the cardanic type or resilient or elastic type.

10-A sail to be used in the windsurf table according to any preceding claims,characterized in that it either provided or not with an inflexion angle. 11- A sail according to claims 1 to 9,characterized in that it is either provided or not with a dihedral configuration.

12- A sail according to claims 1 to 9,characterized in that it is of the constant chord type or of the not constant chord type.

13- A sail according to claims 1 to 9,characterized in that it is made from a simple sheet of the ' cloth conventionally used for making sails or from a double sheet of the same material.

14- A sail according to claims 1 to 9,characterized in that it is either inserted into a wing shaft or not.

Drawing