WO2014060600A1

WO2014060600A1 - Fitting and stay made out of composite material

Info

Publication number: WO2014060600A1
Application number: PCT/EP2013/071896
Authority: WO
Inventors: Andreas Winistoerfer; Iwan Stoecklin
Original assignee: Carbo-Link Ag
Priority date: 2012-10-19
Filing date: 2013-10-18
Publication date: 2014-04-24

Abstract

The invention concerns a fitting (2) comprising a first thimble (9) and a second thimble (10) arranged at a distance (T) with respect to the first thimble (9). The first thimble (9) is having a first outer surface (25) being encompassed by a first loop (19) of composite material and the second thimble (10) is having a second outer surface (25) being encompassed by a second loop (20) of composite material. The first and the said second loop (19, 20) of composite material merge into a load transfer element (2). The invention further concerns a stay (1) and a furling system (13) comprising a stay (1).

Description

FITTING AND STAY MADE OUT OF COMPOSITE MATERIAL

FIELD OF THE INVENTION

The present invention relates to a fitting, a stay (forestay, backstay, shroud) and a system thereof, e.g. for sale boats and the like, according to the preamble of patent claims.

BACKGROUND OF THE INVENTION

On a sailing vessel, the forestay is a cable of the rigging, which keeps the mast in position and prevents it from falling over. At the upper end, the forestay is attached to the mast either at the top or at a certain distance below the top. At the bottom, the forestay is attached to the body of the vessel at the bracer.

Normally, a sail (genua, jib) is attached to the forestay, which often can be furled around the forestay to shorten or store the sail in a convenient manner. I n smaller vessels both ends of the forestay are arranged rotatable around the length axis of the forestay such that the sail can be furled on the forestay by rotating the fore- stay around its axis. However, with larger vessels where the forces in the forestay are much higher this is not possible. Therefore, a so called furling tube is arranged around the forestay in a rotatable manner. To keep the furling tube centered with respect to the forestay, bearings are arranged between the forestay and the furling tube. The forestay of standard sailing vessels is typically made of a stainless steel cable. However, in high-performance sailing vessels (as e.g . used in races), the forestay is more often made out of carbon fibres embed in a polymer matrix to reduce weight and to increase the performance. Compared to a forestay made out of stainless steel, a forestay made out of carbon fibre can be more easily tailor made and customized.

However, forestays made out of carbon fibre are (compared to stainless steel cables) more difficult to attach as normal splicing is not an option. For good results, the fibres are normally arranged at least partially around a fitting (body) , whereby the size of the fitting body is dimensioned according to the occurring working loads. As in so-called super yachts, working loads of up to 1 00 tons may occur, the size (diameter) of the fitting may become a problem, especially when a furling tube is to be arranged around the forestay. As the fittings are attached to the forestay in the factory and the furling tube has then to be slid over the fitting, the inner diameter of the furling tube is determined by the diameter of the fitting. This is counterproductive as it may negatively affect the sailing performance because normally it is an aim to reduce the diameter of the furling tube. From the prior art no solution is known to overcome this problem.

WO09022957 was filed in the name of Peter Norlin and published in February 2009. It describes a furling staysail device which, has a driving dog for the tack of the staysail located immediately above the deck of the boat. A forestay extends through the deck and a bevel gear is mounted immediately below the deck above the lower attachment of the forestay.

WO07048932 was filed in the name of Ludovic Broquaire and first published in April 2007. It is directed to an end device of a shroud comprising a rod and a terminal part designed to be fixed to a stationary point by a connecting means. The end of the rod is formed by rod segments with decreasing cross-section . Each segment is having a constant cross-section smaller than the cross-section of the preceding segment and greater than the cross-section of the following segment moving towards the end of the rod . Furthermore, each segment comprises successive carbon fibre layers of common direction in an epoxy resin binder.

EP1 5801 1 8 was filed in the name of Renzo Greghi and first published in J une 2004. It describes a sail furling and unfurling device which comprises at least an outer foil wound about and made rigid with an inner foil or stay designed for transmitting the furling torque required for furling a sail being wound on a sheath profiled element. The device allows furling and unfurling large downwind foresails, i.e. asymmetrical spinnakers or the like, such as gennakers and can be easily used to hoist and lower the sails. The inner foil comprises a sheet or rope or a unidirectional fibre assembly. The outer foil comprises a flexible strip wound on said inner foil and made rigid with said inner foil or a crossed-fibre assembly by thermally processing said fibers. EP1 595262 was filed in the name of Thomas George and first published in August 2004. It describes a composite tension rod, which is received in a sleeve portion of a shank that forms part of a terminal fitting . In one embodiment a tension rod sleeve is fixed to the tension rod and extends over the distal end of the shank sleeve and along all or a majority of the length of the shank sleeve. The rod sleeve is tapered so that its wall thickness decreases to a minimum in the vicinity of the proximal end of the shank sleeve, or the rod sleeve, as it extends along the shank sleeve, is divided or divides, into two halves or bands which join to form loop extending around a loop-engaging , convex, fibre-turnaround face formed on the terminal fitting .

WO03033814 was filed on behalf of Boyce Spars Holdings Ltd . and first published in December 2001 . It describes a method for manufacturing a composite elongate structural member with two through-holes. The method comprises the following method steps: Providing two spaced apart mandrels. Winding at least one tow of composite prepreg around the outer sides of both of said two spaced apart mandrels together. Heating said wound tow between and around said mandrels to cure resin in said composite prepreg, thereby to solidify said tow as said composite elongate structural member with said through-holes being formed by said mandrels.

EP081 5329 was filed in the name of the same applicant and first published in September 1 996. It describes a loop-shaped anchorage or retaining element for anchoring, reinforcing, securing or keeping assembled structural or mechanical parts, construction elements, structures or parts thereof or for introducing at least one force component. The anchorage or retaining element comprises a plurality of superimposed, loops, strips or layers.

US3749043 was filed in the name of Donald H . Crall and first published in J uly 5 1 97 1 . It describes a spool sections which is rotatably mounted on the jib stay.

Each section is formed of two identical halves which are fixed together by screws or clips. The two parts in cross-section are formed with a central hole which receives the stay. A drum consisting of two sections screwed together and fixed to the lowermost spool section receives a furling line used to revolve the spool sec- i o tions and furl or reef the sail.

US4924795 was filed on behalf of International Marine Industries and first published in May 1 990. It describes a winch mechanism for turning a fairing about a stay and spirally winding a sail to and from the fairing . The winch includes a high mechanical advantage clutch. The clutch driving shaft is usually driven by a hy- 1 5 draulic motor.

SUMMARY OF THE INVENTION

It is an object of the herein disclosed invention to overcome the above problems by providing an improved fitting and stay and a system thereof. A fitting according to the invention in general comprises two or more load application elements in the form of thimbles. Each thimble comprises a geometric axis. The thimbles are arranged with respect to a longitudinal direction (in which a main load transfer takes place) behind each other whereby their geometric axis is normally arranged parallel to each other each crossing the axis of the longitudinal direction perpendicular. If appropriate, the geometric axis of the thimbles is not parallel with respect to each other. E.g . the axes of at least two thimbles are arranged at an angle with respect to each other. A fitting according to the invention offers the advantages of a very slender design while comprising a very high load bearing capacity.

In an embodiment, the invention comprises a fitting with a first thimble and a second thimble arranged at a distance to the first thimble. The first and the said second thimble are, with respect to a longitudinal axis in which a majority of a force is transmitted, arranged behind each other. The first and the second thimble each comprise an opening (hole) for fixing the fitting to a counter part, e.g . for receiving a mandrel or a bolt. The axis of the holes are normally arranged transversal to the longitudinal direction. The first and the second thimble are each having an outer surface. The outer surface of the first thimble is at least partially encompassed by a first loop of composite material (normally fibers embedded in polymeric matrix) and the outer surface of the second thimble is encompassed by a second loop of composite material. The composite material of the first loop and the composite material of the second loop are normally the same, i.e. having the same material properties. However, depending on the field of application, the composite materials can be different. The composite material can comprise carbon, glass or Aramid® fibers or a mixture thereof. The first and the second loop of composite material merge into or are attached to a load transfer element arranged in the longitudinal direction. In a preferred embodiment, the load transfer 5 element is a beam. Good results are achieved when a spacer is arranged between the first and the second thimble. The spacer e.g. consists of foam or another suitable material . The spacer preferably has a lateral surface which has a convex shape and which in a mounted position supports the fibers at least of the second loop. The lateral surfaces of the spacer are normally arranged tangential to an i o outer surface of the first and/or the second thimble. The cross-section of the composite material forming the second loop is normally larger then the cross- section of the composite material forming the first loop which has a positive effect on the load carrying capacity. The cross-section of the loops preferably corresponds to the projected area given by the diameter and the width of each thimble,

1 5 i.e. the factor given by the cross-section area of each loop and the projected area defined by the outer diameter of each thimble and its width is for each loop the same (within a tolerance of 5 % ) . It is possible to foresee more then two thimbles. The additional thimble and the corresponding loop of composite material encompassing it preferably fulfill the above mentioned conditions with respect to their

20 adjacent thimble and loop. The same in general applies for a spacer arranged in- between them.

A fitting according to the invention is preferably integrated in a stay of a sailing vessel. The stay comprises a fitting at least at one end . If appropriate, the stay can comprise more than two ends, e.g. when used as a shroud with different attachment points to a mast. E.g. it is possible that the composite material of each loop corresponds to individual attachment points. In a variation the composite material of a main branch to which a fitting according to the invention is attached, may be 5 branched off into several smaller branches which have the same or a different diameter/cross-section of composite material. Alternatively or in addition, a fitting according to the invention may be attached to at least one end of at least one smaller branch. In a further variation, a standard fitting is attached to the main branch and one or several fittings according to the invention are attached to an i o end of at least one smaller branch. If required, it is possible to subdivide the main branch and/or at least one smaller branch, whereby at least one end may be terminated with a fitting according to the invention . Preferably, the cross-section of each branch is adopted to the load to be transferred, whereby the sum of the load carrying fibers of the smaller branches corresponds to the sum of the load carry-

1 5 ing fibers of the main branch. Local reinforcements may be foreseen if required .

The stay normally comprises a beam which consists out of the fibres of at least two loops. The beam may have a circular and/or wing-like cross-section. If appropriate, the cross-section (e.g. the shape of the cross-section ) of the beam may change over its length . In a preferred embodiment the beam is encompassed by a 20 shrink foil. The stay may have on both ends connecting means for connecting of a power supply. This offers the possibility to cure to composite material of the stay when in a mounted position, e.g . on a vessel . Thereby, the stay especially when long is more convenient to transport as it is more flexible and the bending radius is much smaller. For curing of the composite material the conductivity of the (carbon ) fibres can be used . If required a heating resistor can be embedded in or surrounding the composite material of the stay and or the at least one fitting . The composite material of the fitting is preferably cured in the factory. This aspect can be used in connection with other stays not described herein.

A stay according to the invention is preferably integrated in furling system by which a sail can be furled for reefing purposes or for recovery of the sail . The furling system normally comprises a furling tube which in a mounted position encompasses the stay. The furling tube preferably is made out of composite material . If required, the furling tube is segmented . The furling tube may be supported on the stay by one or more bearings. The bearing preferably is a ball or a roller bearing to ensure smooth operation. If required the bearing is dividable in a lateral direction. Alternatively or in addition the bearing is a floating bearing . Depending on the field of application and the kind of furling tube, a certain amount of clearance may be foreseen between the bearing which is attached to the stay and the inner surface of the furling tube. Thereby, it is possible to use the stay according to the invention in combination with common furling tubes, i.e. furling tubes which comprise segments interconnected to each other by bushings which protrude above the inner surface of the furling tube.

A method for making of a stay according the invention comprising a fitting on both ends in general comprises the following method steps: (a) Arranging a first thimble (of a first fitting) and at least one third thimble (of a second fitting) at a distance which corresponds to the length of the stay in a longitudinal direction away from each other.

(b) Winding fibers around the first and the third thimble until the fibers forming a first loop around the first thimble has achieved a predefined first amount of fibers;

(c) Arranging a second thimble in the longitudinal direction on the opposite side of the first thimble (with respect to the third thimble);

(d) Winding the same or one or more of a different type of fibres around the second thimble and the at least one third thimble until the loop encompassing the second thimble achieves a predetermine second amount of fibers;

(e) Curing the fibers at least in the region of the thimbles.

If appropriate both ends (fittings) of the stay may comprise two or more thimbles. Both may have an identical setup. Good results are achieved when between the first and the second thimble a spacer is arranged . The spacer preferably has concave side surfaces which support the fibers of the second loop in lateral direction. The concave surface preferably is arranged tangential to an outer surface of the thimble and/or one of the loops. If appropriate the fibers extending between the first, the second and the at least one third thimble can be pressed into or circumferentially wrapped by a foil or other fibers to form a beam having specifically shaped cross-section, e.g . round . The foil can be a shrink foil which can be thermally or by other means activated .

While making a stay according to the invention, the fibers which are wound around the thimbles arranged at a distance to each other are first arranged in several layers (loops) of unidirectional fibers, each having the same or a different thickness. The layers normally consist of ribbons of fibers which are preferably already encompassed by a matrix material which is not yet cured . Depending on the field of application, layers of fibers made out of different materials or with different orientations of the fibers may be combined . If appropriate, several layers of fibers may be branched off from the beam forming separate ends.

To cure the fibers the stay may comprise on both ends means to connect (connector) the stay to a power supply by which a current can be transmitted in longitudinal direction of the stay either through the fibers and/or another heating resistor. At least one thimble can be designed to act as a connector for the power supply. By this it becomes possible to cure at least the fibers arranged between the ends (fittings) of the stay by heating which takes place due to the electrical current when the stay is already in amounted position, e.g. in the form of a stay of a sailing vessel . BRIEF DESCRIPTION OF THE DRAWINGS

The herein described invention will be more fully understood from the detailed description given herein below and the accompanying drawings, which should not be considered limiting to the invention described in the appended claims. The drawings are showing :

Fig. 1 a forestay system in a perspective view;

Fig. 2 a first, lower fitting in a perspective and partially cut manner;

Fig. 3 the first, lower fitting in a top and a cross-sectional view;

Fig. 4 a second, upper fitting in a perspective manner;

Fig. 5 a furling tube;

Fig. 6 a bearing;

Fig. 7 a stay with several branches.

DESCRIPTION OF THE EMBODIMENTS

Figure 1 shows a stay (forestay) 1 according to the present invention . The stay 1 is made out of carbon fibres embedded in a polymeric matrix. It comprises a beam 2 (load transfer element) with a cylindrical cross-section which on one end is connected to a lower first fitting 3 (see Figures 2 and 3) and an upper second fitting 4 (see Figure 4) integrally connected to the stay 1 . The beam 2 is encompassed by a furling tube 5 (see Figure 5 ) . The furling tube 5 of the shown embodiment consists of segments 6 which are interconnected by adapters 7. Selected segments 6 and the adapters 7 are shown partially cut and in an exploded manner such that the setup becomes better apparent. The furling tube 5 is in radial direction supported with respect to the stay 1 by bearings 8 (see Figure 6) .

As it can best be seen in Figures 2 and 3, the first fitting 3 comprises a first smaller and a second larger thimble 9, 1 0. The thimbles 9, 1 0 are arranged behind each other with respect to a first axis 1 1 of the beam 2 spaced a distance T. Their orientation is transverse to the first axis 1 1 of the beam 2. If appropriate, the first fitting 3 may comprise more then two thimbles arranged behind each other. The thimbles 9, 1 0 must not necessarily have a rotational symmetric design . Non- symmetric designs, which provide better load distribution and smooth transitions, are preferred .

Figure 2a shows the lower fitting 3 attached to a counter element 1 2. The assembly is shown partially cut such that the inner setup becomes apparent. The counter element 1 2 is shaped as a claw with two brackets 1 4 encompassing the lower fitting 3 on two opposite sides. The interconnection between the fitting 3 and the counter element 1 2 is caused by a first and a second mandrel 1 5 , 1 6, which in a mounted position (as shown ) are arranged extending across the first and the second thimble 9, 1 0 and corresponding to first and second openings 1 7, 1 8 of the brackets 1 4.

Figure 2b shows the first fitting 3 in a partially cut manner. Figure 3a shows the first fitting 3 in a top view and Figure 3b shows a section view of the first fitting along section line AA according to Figure 3a.

As it can be seen, the first thimble 9 is along an outer surface 25 surrounded by a first loop 1 9 and the second thimble 1 0 is surrounded along an outer surface 25 by a second loop 20 of composite material which smoothly merges into the beam 2 forming the stay 1 . In the shown embodiment, a spacer 2 1 made out of a spacer material, such as rigid foam material is arranged between the first and the second thimble 9, 1 0. The first and the second thimble 9, 1 0 each comprise a bushing 22. At each end the bushing 22 comprises a rim 23 protruding in radial direction, which supports and protects the composite material of the first and the second loop 1 9, 20. The thimbles 9, 1 0 are preferably made out of stainless steel or titanium or any other durable material .

As visible in the sectional view of Figure 3b, the first and the second thimble 9, 1 0 are having different diameters D 1 , D2. For best load distribution the outer diameter D2 of the second thimble 1 0 is similar or larger then the diameter D 1 ' of the first thimble in combination with the composite material forming the first loop 1 9. The radial thickness of the composite material forming the first loop 1 9 and the second loop 20 are in the shown embodiment chosen that the load carrying capacity given corresponds to a projected area given by the diameter D 1 , D2 and the width B of each thimble (respectively the corresponding loop 1 9, 20) . In the shown embodiment, more fibres encompass the second thimble 1 0 then the first thimble 9, i.e. when the width B is the same, the thickness of the second loop 20 is larger then the thickness of the first loop 1 9. The same would apply if the first fitting 3 would comprise more then two thimbles arranged behind each other. However, depending on the field of application other material thickness is appropriate. As it can be seen, the diameter D2 of the second thimble 1 0 is in the shown embodiment larger then the diameter D 1 ' of the first thimble 9 in combination with the thickness of the composite material forming the first loop 1 9. To compensate this and for best distribution of occurring forces, the outer shape of the spacer 21 infills the space between the first and the second thimble 9, 1 0, respectively the first loop 1 9 and the second thimble 20. Furthermore, it is tangential to the circles D 1 ' and D2 and comprises slightly diverging side faces compensating the different diameters. Lateral surfaces 24 which support the fibres of the second loop 20 from the inside, are having in the shown embodiment a convex curved design protruding in an outward direction, thereby actively supporting the fibres of the loop 20. If appropriate, the area before the first thimble 9 can be filled out by an additional spacer in a similar manner. The first fitting 3 may comprise more then two thimbles.

Advantages of the shown first fitting are the high load capacity and compared to this the slim design which allows significant reduction of the diameter of the furl- ing tube. The slim design furthermore allows accommodating the first fitting 3 e.g. within a rotary drive for the furling tube 5 (see Figure 1 ) or below a deck of a vessel. A further advantage is the cost effective production.

Figure 4 shows the second fitting 4 which forms the counter part to the first fitting 2 on the opposite end of the beam 2 (see Figure 1 ) . The second fitting 4 comprises a third thimble 26 with a hole 27 for fastening of the second fitting 4, e.g . to a mast. The third thimble 26 has a bushing 28 which forms the inner part of the thimble. The outer surface of the bushing 28 merges into two wing-like extensions 29, which extend along a third loop 30 of composite material encompassing the third thimble 26. The material of the third loop 30 corresponds to the material forming the first and the second loop 1 9, 20 of the first fitting. If appropriate the second fitting 4 may have the same design as the first fitting .

Figure 5 is showing in a simplified manner two segments 6 of a furling tube 5 in a perspective manner. The segments 6 are preferably made out of composite material each having at least one inner conical surface 3 1 (see section cut segment on the left side of the drawing ) which corresponds to at least one outer conical surface 32 of the adapter 7. The segments 5 are interconnected to each other via the adapter 7 by gluing of the conical surfaces 3 1 , 32 to each other. Alternatively or in addition the segments 5 can be interconnected by riveting or a screwing connection . The segments 6 of the furling tube 5 as well as the adapters 7 are hollow. The segments 6 of the furling tube 5 are having a first inner surface 33 and the adapter 7 is having a second inner surface 34. Both inner surfaces are preferably cylindrical and have in principle a similar diameter D3. The furling tube 5 comprises a slotted sleeve 35 which extends in longitudinal direction (x) across several segments 6 and which is suitable to receive an enlarged leading edge of a sail (not shown in detail) . The adapter 7 may be integrated in one end of the furling tubes 5, i.e. the furling tube 5 itself comprises an outer conical surface at one end and an inner conical surface at the opposite end . Thereby, it is possible to joint two similar tube segments 5.

Figure 6a shows a bearing 8 in a mount position on a beam 2. Figure 6b shows the bearing in a disassembled manner. The bearing comprises an in general cylindrical main body 36 which comprises a first and a second semi shell 37, 38 which in the shown embodiment are having a symmetrical design . The two semi shells may be interconnected to each other along an interaction plane 39 by bolts 40. Thereby it is possible to mount the bearing 8 onto an existing beam 2. As visible in Figure 6b each of the semi shells 37, 38 comprises two opposite circumferential channels 41 which serve as guiding means for rollers 42. In a mounted position e.g. in a furling system 1 3 as shown in Figure 1 the rollers 42 interact on the inside with a cylindrical surface 43 of the main body 36. On the outside the rollers 42 interact with an inner surface 33 of the furling tube 5. If appropriate the rollers 42 can be replaced by one or several rows of spheres. Furthermore it is possible to guide and/or hold the rollers within a cage surrounding the rollers 42 in circumferential direction. Figure 7 schematically shows a further embodiment of a stay 1 according to the invention . The stay 1 comprises a beam 2 with a cylindrical and/or at least partially a different cross section . The stay 1 comprises at the lower end a first fitting 3 as shown and described above. At the upper end the stay comprises a second fitting 4 as shown an described above. Furthermore the stay 1 here comprises two branches 44 each comprising a third fitting 45 which separate from the beam 2 at a crotch 46. The composite material forming the branches 44 is branched off from the composite material forming the ( main ) beam 2. Thereby the cross- section of the beam 2 is reduced in the direction of the second fitting 4. The fibers forming the branches 44 normally extend along the beam 2 in the direction of the first fitting 3 where they encompass at least one of the thimbles 9, 1 0. This embodiment can e.g . by used as a side-stay of a high performance sail vessel. It offers the advantage of low drag and optimized force distribution.

In a variation, the composite material of a main branch 2 is branched off into sev- eral smaller branches 44, which have the same or a different diameter/cross- section of composite material. Alternatively or in addition, a fitting 3 according to the invention having more then one thimble may be attached to at least one end of at least one smaller branches 44. In a further variation, a standard fitting as known from the prior art is attached to the main branch 2 and one or several fit- tings 3 according to the invention are attached to an end of at least one smaller branch 44. If required, it is possible to subdivide the main branch and/or at least one smaller branch, whereby at least one end may be terminated with a fitting according to the invention . Preferably, the cross-section of each branch is adopted to the load to be transferred, whereby the sum of the load carrying fibers of the smaller branches corresponds to the sum of the load carrying fibers of the main branch. Local reinforcements may be foreseen if required .

LIST OF DESIGNATIONS

D 1 Diameter first thimble 1 0 Second Thimble (thimble) D 1 ' Diameter of first thimble plus 1 1 First axis (beam)

composite material of first 25 1 2 Counter element (head ) 5 loop. 1 3 Furling system

D2 Diameter second thimble 1 4 Bracket

D2' Diameter of second thimble 1 5 First mandrel (smaller)

plus composite material of 1 6 Second mandrel (larger) second loop. 30 1 7 First opening (smaller) i o D3 Inner diameter of segment 1 8 Second opening (larger)

B Width of loop 1 9 First, smaller loop (composite T Distance between first and material )

second thimble. 20 Second, larger loop (compos1 Stay 35 ite material)

1 5 2 Beam (load transfer element) 2 1 Spacer (first fitting)

3 First, lower fitting 22 Bushing (thimble)

4 Second, upper fitting 23 Rim (thimble)

5 Furling Tube (Tube) 24 Lateral surface (spacer)

6 Segment (furling tube) 40 25 Outer surface (thimble)

20 7 Adapter (between segments) 26 Third thimble (thimble)

8 Bearing 27 Hole (third thimble)

9 First thimble (thimble) 28 Bushing (third thimble) Extension (thimble) 38 Second semi shell

Third loop (composite mate^¬ 39 Interaction plane rial) 40 Bolt

Inner conical surface 41 Channel (for rollers)

Outer conical surface 1 5 42 Roller

First inner surface 43 Cylindrical surface

Second inner surface 44 Branch

Slotted sleeve 45 Third fitting

Main body (bearing ) 46 Crotch

First semi shell

Claims

PATENT CLAIMS

1. Fitting (3) comprising a. a firstthimble (9) and b. a second thimble (10) arranged at a distance to the first thimble (9) c. said first and said second thimble (9, 10) being with respect to a longitudinal axis (x) arranged behind each other and transversal to the longitudinal axis (x), d. said first thimble (9) having a first outer surface (25) being encompassed by a first loop ( 19) of composite material and e. said second thimble (10) having a second outer surface (25) being encompassed by a second loop (20) of composite material, wherein f. said first and said second loop (19, 20) of composite material merge into a load transfer element (2).

2. The fitting (3) according to claim 1 , wherein the load transfer element is a beam (2).

3. The fitting (3) according to one of the previous claims, wherein the composite material encompassing the first thimble (9) and the composite material encompassing the second thimble (10) are the same or of a different type.

4. The fitting (3) according to one of the previous claims, wherein a spacer (21 ) is arranged between the first and the second thimble (9, 10).

5. The fitting (3) according to claim 4, wherein a lateral surface (24) of the spacer (21 ) has a convex shape.

6. The fitting (3) according to one of the claims 4 or 5, wherein the lateral surface (24) of the spacer (21) is arranged tangential to an outer surface of the first and the second thimble (9, 10).

7. The fitting (3) according to one of the previous claims, wherein the cross- section of the composite material forming the second loop (20) is larger then the cross-section of the composite material forming the first loop (19).

8. The fitting (3) according to claim 7, wherein the cross-section of the loops (19, 20) corresponds to the projected area given by the diameter and the width of the corresponding thimble (9, 10).

9. Stay (1 ) comprising a fitting (3) according to one of the previous claims.

10. The stay ( 1 ) according to claim 9, wherein the stay ( 1 ) comprises a beam (2), which consists out of the fibres of at least two loops ( 19, 20).

11. The stay ( 1 ) according to one of the claims 9 or 10, wherein the beam (2) has a circular and/or wing-like cross-section.

12. The stay ( 1 ) according to one of the claims 9 to 11 , wherein the beam (2) is encompassed by a shrink foil.

13. The stay ( 1 ) according to one of the claims 9 to 12, wherein the stay ( 1 ) comprises at least one branch (44) branching off at at least one crotch (46).

14. The stay (1 ) according to one of the claims 9 to 13, wherein the stay (1 ) has in the region of both ends connecting means for connecting of a power supply.

15. Furling system comprising a stay (1 ) according to one of the claims 9 to 14.

16. The furling system according to claim 15, wherein the furling system comprises a furling tube (5) which encompasses the stay (1 ).

17. The furling system according to claim 16, wherein the furling tube (5) is segmented.

18. The furling system according to one of the claims 1 5 to 1 7, wherein the furling tube ( 5) is made out of composite material.

19. The furling system according to one of the claims 1 5 to 1 8, wherein the furling tube ( 5) is supported with respect to the stay by a bearing (8) .

20. The furling system according to claim 1 9, wherein the bearing (8) is a ball and/or a roller and/or a floating bearing .

21 . The furling system according to claim 20, wherein the bearing (8) is divid- able in a lateral direction.

22. Bearing (8) suitable to be used in a furling system according to one of the claims 1 5 to 21 wherein the bearing comprises a main body separable in two semi shells and several rollers or spheres or floating elements.

23. A method for making of a stay ( 1 ) according to one of the claims 9 to 1 3 comprising the following method steps: a. Arranging a first thimble ( 1 9 ) of a first fitting (3 ) and at least one third thimble ( 26 ) of a second fitting (4) at a distance which corresponds to the length of the stay ( 1 ) in a longitudinal direction away from each other; Winding fibers around the first and the third thimble (9, 26) until the fibers forming a first loop (19) around the first thimble has achieved a predefined first amount of fibers;

Arranging a second thimble (10) in the longitudinal direction on the opposite side of the first thimble (9) with respect to the third thimble (26);

Winding the same or one or more of a different type of fibers around the second thimble (10) and the at least one third thimble (26) until the loop (20) encompassing the second thimble (10) achieves a predetermine second amount of fibers; Curing the fibers (2, 19, 20) at least in the region of the thimbles (9, 10, 26).