NZ555904A

NZ555904A - Method of manufacturing a wind turbine blade shell member with a fastening member and a wind turbine blade with a fastening member

Info

Publication number: NZ555904A
Application number: NZ555904A
Authority: NZ
Inventors: Mark Hancock; Anton Bech
Original assignee: Vestas Wind Sys As
Priority date: 2004-12-29
Filing date: 2004-12-29
Publication date: 2009-11-27

Abstract

A method of manufacturing a wind turbine blade shell member 2 with a fastening member 4 provided near a root end of the wind turbine blade shell member 2, the fastening member 4 being suitable for connecting a wind turbine blade comprising the wind turbine blade shell member 2 to a wind turbine hub, the method comprising the steps of providing a rigid outer mould 14 16, positioning the fastening member 4 near the end of the rigid outer mould 14 16 corresponding to the root end of the wind turbine blade, positioning at least two layers of pre-fabricated sticks 8 10near the end of the rigid outer mould 14 16 corresponding to the root end of the wind turbine blade such that prefabricated sticks 8 10surround a substantial longitudinal part of the fastening member 4 when the fastening member 4 is positioned in the wind turbine blade shell member 2, positioning one or more layers of pre-fabricated sticks 8 10in a substantial longitudinal part of the rigid outer mould 14 16, thereafter providing an inner mould in vacuum-tight connection with the rigid outer mould 14 16, evacuating the volume between the outer and the inner moulds, infusing a curable resin to secure the fastening member 4 to the enclosing pre-fabricated sticks 8 10and substantially fill empty space between adjacent sticks, and allowing the resin to cure, de-moulding the wind turbine blade shell member 2.

Description

<div class="application article clearfix" id="description"> WO 2006/070171 PC T/GB2004/005433 METHOD OF MANUFACTURING A WIND TURBINE BLADE SHELL MEMBER WITH A FASTENING MEMBER AND A WIND TURBINE BLADE WITH A FASTENING MEMBER 5 Method of manufacturing a wind turbine blade shell member with a fastening member and a wind turbine blade with a fastening member TECHNICAL FIELD OF THE INVENTION 10 The invention relates to a wind turbine blade. More particularly, the invention relates to a method of manufacturing a wind turbine blade shell member with a fastening member for connecting a wind turbine blade comprising the wind turbine blade shell member to a wind turbine hub and a wind turbine blade with a fastening member, 15 Furthermore, the invention relates to a wind turbine blade shell member and a wind turbine blade with an embedded fastening member. BACKGROUND OF THE INVENTION 20 Wind turbines are used for converting the power of wind to a source of energy, typically electrical energy. In recent years, the use of yet larger wind turbines has increased the requirements of the connection between the wind turbine blades and the flange of the wind turbine hub. A critical feature is the connection between the 25 fastening members for securing the blade to the hub, which fastening members are provided at the blade root of the blade and the rest of the blade as this connection is subjected to large and cyclic loads during operation. A durable and yet affordable wind turbine blade manufactured by combining pre-30 fabricated sticks by vacuum-assisted resin infusion is disclosed in WO 03/008800. In US 4,915,590 a number of techniques for connecting a wind turbine blade to a hub is described. Particularly the prior art technique described in relation to Fig. 3 of US 4,915,590 is relevant in relation to the present invention. There, steel attachment stud 35 rods are embedded in a wind turbine root by drilling a hole into the end of the wall of the completed wind turbine blade and fixing the attachment stud rods in the hole by CONFIRMATION COPY 555904 2 adhesive. Drilling of holes into the laminated composite structure is very time-consuming, laminate material is wasted and the wear of the drill is considerable. Furthermore, removal of debris from the hole as well as preventing presence of air in the adhesive is complicated due to the length to width ratio of the hole. A considerable space between the attachment stud rod and the walls of the hole is therefore required leading to a large consumption of adhesive, a relatively weak connection and an unduly large blade wall thickness. It has been considered to provide the fastening members prior to curing of the blade. WO 03/082551 discloses a blade connection wherein an insert is inserted into a non-cured laminate structure. The insert is provided with a plurality of elevations and recesses of similar longitudinal size and smaller pieces of parallel laminate layers are provided in the recesses. It is necessary to sew the laminate layers together near the insert to provide sufficient de-lamination strength between the smaller pieces of parallel laminate layers and larger outer laminate layers. Sewing of layers is a very time-consuming and complex process and must either take place from the inner side of the hole or from the outer side during lay-up of the laminate layers. Sewing may also interact with the alignment of fibres leading to a decrease in strength of the laminated structure at the most critical place, namely near the inserts. There is hence a need for a fast and secure method for providing a fastening member in a wind turbine blade. OBJECTS OF THE INVENTION It is the object of the invention to provide a method whereby a fastening member is more efficiently provided in the wind turbine blade, or to at least provide a useful choice. It is another object of the invention to provide a wind turbine blade shell member and a wind turbine blade with an improved connection between the fastening member and the blade, or to at least provide a useful choice. DISCLOSURE OF THE INVENTION intellectual property OFFICE OF N.Z. 3 0 OCT 2M9 received 2196040_l.doc 555904 3 (followed by page 3a) One or more of the above objects of the invention are realised for a wind turbine blade shell member comprising pre-fabricated sticks, the wind turbine shell member being manufactured by the method of claim 1 and/or for a the wind turbine blade according to claim 26, which wind turbine blade comprises a wind turbine blade shell member with pre-fabricated sticks. In broad terms in one aspect the invention comprises a method of manufacturing a wind turbine blade shell member with a fastening member provided near a root end of the wind turbine blade shell member, the fastening member being suitable for connecting a wind turbine blade comprising said wind turbine blade shell member to a wind turbine hub, the method comprising the steps of: providing a rigid outer mould; positioning the fastening member near the end of the rigid outer mould corresponding to the root end of the wind turbine blade; positioning at least two layers of pre-fabricated sticks near the end of the rigid outer mould corresponding to the root end of the wind turbine blade such that pre-fabricated sticks surround a substantial longitudinal part of the fastening member when the fastening member is positioned in the wind turbine blade shell member; positioning one or more layers of pre-fabricated sticks in a substantial longitudinal part of the rigid outer mould; thereafter providing an inner mould in vacuum-tight connection with the rigid outer mould; evacuating the volume between the outer and the inner moulds, infusing a curable resin to secure the fastening member to the enclosing pre-fabricated sticks and substantially fill empty space between adjacent sticks, and allowing the resin to cure; de-moulding the wind turbine blade shell member. The method concerns manufacturing a wind turbine blade shell member with a fastening member provided near the root end of the wind turbine blade shell member. When embedded in the blade, the fastening member is suitable for connecting the wind turbine blade comprising the wind turbine blade shell member to a wind turbine hub. The method comprises providing a rigid outer mould, positioning one or more fastening members near the end of the rigid outer mould corresponding to the root end of the wind turbine blade, positioning at least two but typically more layers of prefabricated sticks near the end of the rigid outer mould corresponding to the root end of the wind turbine blade. The pre-fabricated sticks should be positioned such that they surround a intellectual property office of n.z. 3 0 OCT 2009 received 555904 3a (followed by page 4) substantial longitudinal part of the fastening member when the fastening member is positioned in the wind turbine blade shell member. Furthermore, one or more layers of pre-fabricated sticks are positioned in a substantial longitudinal part of the rigid outer mould. Thereafter, an inner mould typically corresponding to the inner surface of the completed wind turbine blade is provided in vacuum-tight connection with the rigid outer mould and the volume between the outer and the inner moulds is evacuated. A curable resin is infused to secure the fastening member to the enclosing pre-fabricated sticks and at least substantially fill the empty spaces between adjacent sticks, the resin is allowed to cure and the shell member is de-moulded. Optionally, the wind turbine shell member is connected to one or more further shell members or other members prior to or after the de-moulding. The curing may commence during infusion as long as the viscosity is sufficiently low until the infusion is completed. The moulding method is also known as vacuum- assisted resin transfer moulding, VARTM. Due to the large sizes of wind turbine blades, the application of vacuum is highly advantageous over conventional resin transfer moulding. However, if the disclosed principle of embedding of a fastening member is utilised in applications where the resin needs to travel a substantially 2196040_l.doc intellectual property office of n.z. 3 0 OCT 2009 received 555904 4 (followed by page 4a) shorter distance, then other moulding methods, such as e.g. resin transfer moulding, may be applicable. Typically at least 70% of the fastening member is surrounded by pre-fabricated sticks but dependent on the actual design of the fastening member the surrounded fraction may vary. If for example the fastening member is provided with an internally threaded bore, as much as near 100% of the fastening member may be surrounded by prefabricated sticks. On the other hand, if the fastening member is provided with a long rod for connecting to the hub, which rod extends from the fastening member, then as little as 50% of the fastening member may be surrounded by pre-fabricated sticks. Furthermore, the surface topology and/or the surface chemistry may promote or impede the strength of the connection and hence the required fraction to be embedded. In broad terms in another aspect the invention comprises a wind turbine blade comprising a wind turbine blade shell member with pre-fabricated sticks connected by a cured resin, and a plurality of fastening members embedded near a root end of the wind turbine blade, at least two of said fastening members being aligned to facilitate connection to a wind turbine hub, wherein the pre-fabricated sticks adjacent to the fastening member conform to the shape of the fastening member such that a substantial part the fastening member is tightly enclosed by the pre-fabricated sticks. The wind turbine blade comprises a wind turbine blade shell member with prefabricated sticks connected by a cured resin and a plurality of fastening members embedded near a root end of the wind turbine blade. At least two of said fastening members are aligned to facilitate later connection to a wind turbine hub. Having fastening members aligned means that threaded holes therein or rods extending therefrom are aligned substantially in parallel such that they are suitable for the connection of the wind turbine blade to a flange of the hub or another receiving element. In broad terms in a further aspect the invention comprises a guiding means for aligning a fastening member relative to at least one further fastening member and/or for aligning the fastening member relative to the rigid mould, during resin transfer moulding of a wind turbine blade shell member, comprising a generally gas tight plate-like member; a I 3 0 OCT 2009 I {received 555904 4a (followed by page 5) means for obtaining an at least temporary connection between the gas tight plate-like member and at least one fastening member; and a means for obtaining an at least temporary connection between the generally gas tight plate-like member and a rigid outer mould; wherein at least one of said at least temporary connections are gas tight, such that the guiding means are suitable for vacuum-assisted resin transfer moulding. The present invention further relates to preferred embodiments concerning circumstances of methods and products relating to preparation for transfer of lightning to the hub via the fastening members, the surface topology and shape of fastening members, wind turbine blades with high content of structural fibres, guiding means for alignment of fastening members and aspects relating to vacuum-assisted resin transfer moulding. BRIEF DESCRIPTION OF THE DRAWINGS The invention will be explained more fully below with reference to exemplary embodiments as well as the drawings, in which 2196040J .doc 3 0 OCT 2009 I received WO 2006/070171 555904 5 PCT/GB2004/005433 Fig. 1 shows a cross sectional view of a wind turbine blade shell member in a mould Fig. 2 shows various overall shapes of a fastening member, 5 Fig. 3 shows preferred cross sections of a fastening member, Fig. 4 shows preferred surface topographies of a fastening member, Fig. 5 shows a plurality of fastening members connected to a guiding means, 10 Fig. 6 shows a plurality of fastening members connected to a guiding means with fibres woven about the fastening member, and Fig. 7 shows an embodiment with conduction of lightning between a lightning 15 conductor and a fastening member. All the figures are highly schematic and not necessarily to scale, and they show only parts which are necessary in order to elucidate the invention, other parts being omitted or merely suggested. 20 DESCRIPTION OF THE DRAWINGS In Fig. 1, an example of a wind turbine blade shell member 2 in a mould 14, 16 is 25 shown. A plurality of layers of pre-fabricated sticks 8,10 are positioned to conform to a fastening member 4, which advantageously is connected to a guiding means 20 for alignment (see below). The connection is preferably in a vacuum-tight manner to allow for vacuum assisted resin infusion. Such a vacuum-tight connection may for example be realised with a rubber-like element 38. In Fig. 1, the number of layers of pre-30 fabricated sticks 8,10 is four, but the number of layers may vary considerably dependent on the size and design of the shell member. Typical values of layers of prefabricated sticks are 2, 3, 4, 5, 6, 8, 10 or even more layers. Furthermore, a number of optional layers may be provided, such as an outer and/or inner fibre layer 18, a gel coat 19 and/or a lightning conductor, etc. Finally, an inner mould 16 is provided prior to 35 the resin infusion process. WO 2006/070171 555904 6 PCT/GB2004/005433 Pre-fabricated sticks In a highly preferred embodiment of the present invention, a crucial element of the method, the wind turbine blade shell member and the wind turbine blade according to the invention is the pre-fabricated sticks. The pre-fabricated sticks are typically 5 substantially longer in the dimension to be aligned with the length of the shell member than in the other dimensions. The sticks may be chamfered near the end, either to allow for a soft transition to an extending stick or to allow for non-abrupt change in blade properties if the stick is not extended. 10 In a preferred embodiment, at least some of the pre-fabricated sticks are selected from the group of fibrous members, wooden material and hollow members. Examples of preferred fibrous members are pultruded or extruded members preferably comprising carbon fibres and/or glass fibres and/or natural fibres. The pultruded member may be uncured, partially cured or fully cured, but fully cured members are preferred, e.g. due 15 to ease of handling. Examples of preferred wooden members are machined wood with a high strength to weight ratio, such as balsa, birch, etc. The wooden members may also be plywood, preferably comprising balsa, birch or other wooden material with similar properties. Hollow members include hollow polymer-based members, such as blow-moulded sticks, foam sticks, extruded members, optionally comprising fibrous 20 material. The combination of sticks should be chosen to provide a suitable compromise between strength, weight and price. 25 Positioning of pre-fabricated sticks near fastening member In a preferred embodiment, the pre-fabricated sticks to be positioned adjacent to the fastening member are machined or otherwise shaped such that when the sticks are in position, the sticks conform to the shape of the fastening member. Preferably the sticks will conform to the fastening member such that a substantial part of the 30 fastening member is tightly enclosed by the pre-fabricated sticks. By a substantial part of the fastening member is meant that at least about 70% of the fastening member is enclosed or surrounded by pre-fabricated sticks, however, this number may vary to lower than 50% or to near 100% as discussed elsewhere. The non-enclosed part of the fastening member may be accounted for by either one or more longitudinal parts or 35 transverse parts not being enclosed. 555904 7 The enclosed part of the fastening member is typically in the range of about 0.4 to 2 m, dependent on the length of the blade and the thickness of the blade wall. In a preferred embodiment it was found that fastening member in the range of about 0.5 to 0.75 m provided a suitable compromise between weight and strength of the connection between the blade and the fastening member. The diameter of the enclosed part varies as discussed elsewhere. In most cases, a diameter corresponding to the maximum area of the cross section of the enclosed part of the fastening member in the range of about 8 to 20 cm is suitable. However, in a preferred embodiment, a diameter corresponding to the maximum area of the cross section of the enclosed part of the fastening member in the range of about 10 to 15 cm was found to provide a suitable compromise between weight and strength of the fastening member as well as the strength of the connection between the blade and the fastening member. In a preferred embodiment, the sticks are shaped such that they will conform to the fastening member according to the macro surface roughness as discussed elsewhere. This allows for a very low use of resin or adhesive as well as it allows for a highly controllable transition between the properties of the fastening member and the properties of the blade. Fibrous members extending to near the root For very large wind turbine blades, it may be advantageous that some of the prefabricated sticks comprising fibrous material, preferably comprising carbon fibres, extending to near the root end 6 of the wind turbine blade shell member. This may increase the stiffness of the root section of the blade and improve transfer of the load to the fastening member may be realised. In a particularly preferred embodiment, at least one pre-fabricated stick, which stick comprises fibrous material, is positioned adjacent to the fastening member along a substantial longitudinal part of the fastening member. By adjacent is here meant that the stick comprising fibrous material is the stick closest to the fastening member. By substantial longitudinal part of the fastening member is here meant at least 50% of the embedded length of the fastening member. However, it is preferred that the stick is positioned along most of the fastening member, such as at least 75% and more preferably at least 90% of the embedded length of the fastening member. The part of Intellectual property OFPfCE OF N.Z 3 0 OCT 2009 RECEIVPn WO 2006/070171 555904 8 PCT/GB2004/005433 the embedded length along which the fibrous stick may be positioned depends to some extent on the shape of the fastening member, as the mechanical properties of the fibrous material is degraded if the fibres are arranged in a curved relationship. In a highly preferred embodiment, the pre-fabricated stick comprising fibrous material is a 5 pultruded fibrous stick comprising carbon fibres as such a stick typically has a high fibre content and highly aligned fibres. In a preferred embodiment, at least two pultruded fibrous members are positioned adjacent to the fastening member and along a substantial longitudinal part of the 10 fastening member. Particularly, it is preferred to have the pultruded fibrous members arranged around the fastening member such that the arrangement is substantially symmetrical with regard to one or more physical property such as e.g. stiffness, E-modulus, alignment or ultimate strength. 15 For blades having fibrous members extending to near the root it is particularly advantageous to introduce the fastening member prior resin infusion as drilling in the blade shell member comprising such fibrous material leads to very high drilling tool wear and furthermore such drilling is rather time-consuming. 20 Overall shape of fastening member The overall shape of the fastening member may vary depending on the actual materials and use conditions of the blade. In general, it is preferred to reduce presence of sharp or pointy edges as this may serve as a crack initiator. Furthermore, holes with a small opening angle should also be avoided, as the infusing resin may not 25 be able to penetrate all the way to the tip of such holes. In Fig. 2, a number of preferred overall surface shapes of fastening member, which e.g. may be used for the method according to the invention, is shown. Typically, it is preferred that the cross sectional area of the fastening member decreases away from 30 the root of the blade. In such cases, the decrease need not be monotonous or continuous but should represent the overall tendency. This leads to a gradual change in properties from the relatively rigid fastening member to the relatively flexible blade. Examples of such overall shape is the generally conical fastening member shown in Fig. 2A and B, but the overall shape may also be of a more concave nature, e.g. as 35 shown in Fig. 2C. WO 2006/070171 555904 9 PCT/GB2004/005433 If e.g. the blade wall is relatively thick, an overall generally dumb bell (as shown in Fig. 2D) or another anchoring shape may be suitable. Another embodiment with a large size of the end of the fastening member facing away from the root end of the blade is a generally conical fastening member with the wider part facing away from the root end 5 (not shown). These may be advantageous as they provide for a solid mechanical bonding and preserve fastening member material as compared to solid cylindrical fastening member. Cross sectional shape of fastening member 10 The fastening member shown in Fig. 2E represents the principle that the fastening member need not be rotational symmetrical even though rotation-symmetrical fastening member are typically preferred due to easier handling of a rotation-symmetrical fastening member. Fastening members which are not rotation-symmetrical, have a larger surface area per volume-fastening member. Hence, a 15 larger surface is involved in the load transfer from the blade via the resin or adhesive to the fastening member and on to the hub. In Fig. 3, a number of preferred embodiments of cross sectional shapes of fastening members are shown. The cross sections may for example correspond to a cross section along the plane a-a on Fig. 2A > or a similar cross section on any one of the other fastening member on Fig. 2. 20 The circular cross section in Fig. 3A corresponds to a rotation-symmetrical fastening member. The oval cross section shown in Fig. 3B may e.g. be advantageous for relatively thin blade shells if oriented with he major axis generally parallel to the outer surface of the blade shell. However, if a large number of closely spaced fastening 25 members are needed, use of fastening members with an oval section with major axes substantially parallel to the surface may be advantageous. In Fig. 30 to F examples of geometrically regular cross sections are shown, however, the skilled person would realise that irregular or generally regular cross sections may also be applied. The exemplifying shapes are provided to describe the overall idea, whereas for example 30 the sharpness of the edges should be adjusted according to the load pattern and the used resin in the specific application. An example of a cross section having rounded edges are shown in Fig. 3G. Fastening members, which are not rotation-symmetrical, may also be particularly advantageous under special loading patterns and/or for off-centred fastening member. 35 WO 2006/070171 555904 10 PCT/GB2004/005433 Surface of fastening member The surface of the fastening members is preferably modified or designed to strengthen the connection between the resin and the fastening member whereby the overall quality of the connection between the blade and the fastening member is increased. 5 The surface may be prepared for increased mechanical strength and/or chemical strength. An example of mechanical strengthening is interlocking structures, which may be used on several dimensional scales. In a preferred embodiment, the surface roughness of 10 the fastening member is increased on a micrometer to sub-millimetre scale as indicated in Fig. 4A. This may be achieved during manufacturing of the fastening member, e.g. by the use of a rough surface in the mould, or by subsequent surface treatment like e.g. sand blasting or grinding. Alternatively or in addition, the surface roughness may be increased on a millimetre scale, such as by introducing waves of 15 about 1 to 5 millimetre transverse to the longitudinal length of the fastening member as indicated in Fig. 4B. Furthermore, macro surface roughness, e.g. steps, tips or waves in the order of several millimetres to several centimetres, may interlock with the prefabricated strips or resin surrounding the fastening member. Examples of fastening member with macro surface roughness are shown in Fig. 4C to G. Increase in surface 20 roughness may greatly increase the bonding strength and/or decrease the potential problems arising due to variation in properties between the blade and the fastening member. If interlocking structures are provided as indicated in Fig. 4D to F, the size, i.e. the 25 longitudinal extension along the length of the fastening member, of recesses and protruding structures may be similar as shown in Fig. 4D. However, it is highly preferred that the size is adjusted according to the relative strength of the fastening member and the surrounding material filling the recesses of the fastening member (typically resin). In other words, the protrusions of the relatively strong fastening 30 member (typically steel or cast iron) are relatively short as compared to the recesses to be filled with the relatively weak resin, which are relatively long. In Fig. 4E to G examples of this are shown. In Fig. 4E the recesses/protrusions are stepwise, whereas in Fig. 4F the side walls of the recesses/protrusions are angled, which may be advantageous in that the contact angles are less sharp and hence provides reduced 35 tendency to act as crack initiation spots. Fig. 4G shows a series of larger and shorter WO 2006/070171 555904 11 PCT/GB2004/005433 rounded elements. This is a preferred embodiment, as this design allows for substantially vertical sidewalls without any sharp edges. In addition to achieving mechanically interlocking structures, increased surface 5 roughness at all scales increases the surface of the fastening member and hence increases the contact area between the fastening member and the resin or adhesive. Preparation for increased chemical connection strength includes removing of debris from the surface of the fastening member as well as removing of dust, rust, grease, oil, 10 etc. prior to assembling. This may include mechanical removal as well as chemical removal (i.e. use of water and soap or solvents). Furthermore, the surfaces may be chemically treated, e.g. pickled or primed, prior to assembling and/or resin infusion. The fastening member is preferably provided with a connecting means for facilitating 15 the connection of a wind turbine blade comprising the wind turbine shell member to the hub. Typically this connecting means comprises a threaded surface, such as a threaded hole from the root end of the blade into the fastening member or a threaded rod extending from the fastening member. In a particularly preferred embodiment, such a threaded surface may be used for connecting the fastening member to a 20 guiding means (see below) during manufacturing of the wind turbine blade shell member, e.g. during lay-up and/or during resin infusion, and/or during assembling of wind turbine blade shell members to form a wind turbine blade. Guiding means 25 During the manufacture of the wind turbine shell member, a guiding means for aligning the fastening member may advantageously be applied. The guiding means may align the fastening member relative to the mould and/or relative to one or more further fastening member. During use, one or more fastening members are connected to the guiding means. The connection may be temporary in the sense that the guiding means 30 is removed from the fastening member after one or more steps of the manufacturing method. Alternatively, the connection between the fastening member and the guiding means may be permanent, i.e. the guiding means is integrated into the wind turbine shell member during manufacturing. 35 If the fastening member is aligned relative to one or more further fastening members then these fastening members are advantageously also connected to a guiding means WO 2006/070171 555904 12 PCT/GB2004/005433 and preferably to the same guiding means as the fastening member. This allows for a particularly efficient method design since a large number of fastening members may be aligned and thereafter introduced in the wind turbine shell member in one operation. In Fig. 5, a guiding means with a plurality of fastening member connected thereto is shown. The combination of a guiding means 20 and fastening members 4 is preferably prepared prior to the introduction of the fastening member into the wind turbine shell member and hence in this embodiment constitutes a subassembly for the wind turbine shell member by allowing a simultaneous introduction of a plurality of aligned fastening member into the shell member. In a preferred embodiment, the subassembly comprises between 15 to 150 fastening members. The guiding means typically holds between 1/4 of fastening member to be provided at the root of the completed wind turbine blade and all of the fastening members. Particularly, it is preferred that the guiding means holds all of the fastening members for the shell member to be moulded; typically this corresponds to about 1/z of the fastening member to be provided at the root of the completed wind turbine blade. In unfortunate situations, a fastening member may provide a source for delamination or even cracking of the blade shell. This may particularly be the case if the fastening member is positioned relatively near adjacent fastening members. In a preferred embodiment, preventive measures are provided in that fibre material, preferably glass fibres or carbon fibres, are woven between the fastening member as shown in Fig. 6. Fig. 6A indicates this principle in a direction from the end of the fastening member towards the guiding means and B indicates the principle from the side. The fibres may e.g. be dry or impregnated fibre tows, yarns or other collections of fibres. In a particularly preferred embodiment, fibres are woven mainly or solely about the 25% of the fastening member to be embedded nearest the root of the wind turbine blade shell member. However, in some cases, fibres may be woven along a larger part of the fastening member leading to the combination of fastening members, guiding means and fibres, optionally with small prefabricated sticks positioned at one or more openings in the woven fibre structure. Such a combination forms a semicircular wedge extending from the guiding means and may be introduced into a groove or channel in a wind turbine blade root. Further sticks may thereafter be positioned near the combination prior to resin infusion. WO 2006/070171 555904 PCT/GB2004/005433 13 If a temporary connection between the fastening member and the guiding means is utilised, the method of manufacturing may further comprise the step of releasing the temporary connection. Usually, the guiding means should thereafter be removed from 5 the wind turbine blade shell member. The resin infusion is typically vacuum-assisted and hence the guiding means is advantageously generally gas impermeable. Furthermore, the guiding means should in this case also be arranged to provide a gas tight connection between the guiding 10 means and the rigid mould and/or the inner mould. It is preferred that guiding means provide a gas tight connection between both the rigid mould and the inner mould. The gas tight connection may e.g. be provided by rubber-like elements 38, e.g. a flexible O-ring, between the moulds and the guiding means in combination with a locking mechanism to keep the connection. The locking mechanism may involve vacuum force 15 provided by the vacuum for the resin infusion; a mechanical means, such as a clamp, bolt and nut; a chemical means, such as adhesive; or a combination of 2 or more of these. In a preferred embodiment, the connection between the fastening member and the 20 guiding means involves engaging of a threaded hole or a threaded rod of the fastening member with a bolt or a nut via a hole in the guiding means. The threaded hole or rod of the fastening member may advantageously also be suitable for connecting a wind turbine blade comprising the wind turbine shell member to a wind turbine hub. 25 In another preferred embodiment, the connection between the fastening member and the guiding means is generally gas tight. Such a gas tight connection may comprise an O-ring. The O-ring may advantageously be arranged on the vacuum side of the guiding means, since this may prevent infusing resin from interacting with the elements providing the connection between the fastening member and the guiding 30 means. The guiding means for aligning a fastening member during resin transfer moulding of a wind turbine blade shell member, comprises in a preferred embodiment a generally gas tight plate-like member, a means for obtaining a temporary or a permanent 35 connection between the gas tight plate-like member and at least one fastening member, and a means for obtaining a temporary or a permanent connection between WO 2006/070171 555904 14 PCT/GB2004/005433 the generally gas tight plate-like member and the rigid mould. To realise an overall gas tight connection to facilitate vacuum-assisted resin transfer moulding, at least one of the above temporary or permanent connections should be gas tight. However, it is highly preferred that both of the temporary or permanent connections are gas tight. 5 By generally gas tight is meant that the gas flow through the member is very low. Of course it is preferred that the members are absolutely gas tight, however, the members for manufacturing of wind turbine blades are of a significant size and a low leak of gas may be compensated for by continuous vacuum pumping. 10 Lightning conduction Wind turbines and particularly wind turbine blades are highly prone to lightning strikes. Therefore the blades are typically provided with lightning receptors and one or more lightning conductors. Examples of lightning conductors are lightning conductor cables, 15 typically positioned inside the blade, conducting metal mesh and/or carbon fibres positioned in the blade wall and/or with internal reinforcement members. To conduct the lightning from the blade via the hub to the ground, the lightning conductor is preferably connected to the fastening member such that the lightning is conducted between the blade and the hub via the fastening member. 20 It is therefore preferred to arrange the lightning conductor in potential equalising communication with the fastening member. This may be realised by connecting the lightning conductor directly to one or more fastening member, however, this may lead to a poor electrical connection with a resulting large contact resistance and hence a 25 significant risk of heating damage upon lightning strike. It is therefore highly preferred to provide a dedicated lightning transfer means for decreasing the contact resistance between the fastening member and the lightning conductor during operation. The lightning transfer means may e.g. be a conducting 30 flange connecting one or more lightning conductors to one or more fastening members. It is preferred that the lightning transfer means is connected to a plurality of fastening members to increase the efficient lightning conducting cross section of the fastening members. In another embodiment shown in Fig. 7, the lightning transfer means 24 comprises a sheet of conducting material, which is positioned adjacent to 35 the lightning conductor 22. In a preferred embodiment, the lightning transfer means 24 is either sandwiched between several lightning conductors 22 and/or the lightning WO 2006/070171 555904 15 PCT/GB2004/005433 transfer means 24 is sandwiching the lightning conductor with one or more lightning transfer means 24. This embodiment is particularly suitable for lightning conductors of the metal-mesh-conductor type since a rather large contact area may be achieved in this way. In yet another embodiment, the lightning transfer means comprises carbon 5 fibres, such as a carbon fleece, a carbon fibre web or a carbon fibre mat, which decreases the contact resistance of the connection even when wetted with resin. It is preferred that the lightning conductor is in communication with the fastening member adjacent to the root end of the wind turbine blade shell member as this 10 decreases the distance that the lightning must travel inside the fastening members and hence decreases the likelihood of heating damage of the fastening members and surrounding material. Further elements of blade and shell member 15 In addition to the already mentioned elements and steps, further elements may optionally but typically preferably be comprised. Examples of such optional elements are applying of surface material such as a gel coat, applying of a lightning conductor, such as a metal mesh and/or a lightning conductor cable, and applying one or more layers comprising fibre material near the inner or the outer surface of the shell 20 element. The fibre material preferably comprises glass fibres and/or carbon fibres. The optional elements may be applied to the mould or to an element in the mould - which is advantageous as a fast procedure and homogeneous product may be realised - or after the moulding. 25 Manufacturing of a wind turbine blade Typically, two or more wind turbine blade shell members are used for a wind turbine blade. A wind turbine blade may be manufactured by securing a wind turbine blade shell 30 member manufacturable by the method according to the present invention to one or more additional turbine blade shell member to form a wind turbine blade. The securing typically involves mechanical fastening means, such as fasteners, e.g. bolts and nuts, screws etc., chemical means, such as adhesive, or a combination. Optionally, further elements, such as a spar or a spacer element may also be provided. It is preferred to 35 use an adhesive identical to or based on similar compounds as the resin used for the (vacuum-assisted) resin transfer moulding. 555904 16 In another method of utilising the wind turbine blade shell members manufactured according to the invention for preparing a wind turbine blade, a multiplicity of such wind turbine blade shell members are secured together such that the fastening member of two or more of the wind turbine blade shell members are aligned. This alignment many advantageously be realised by aligning the guiding means corresponding to each of the wind turbine shell members. As more than one fastening member typically are connected to each guiding means, a large number of fastening members may rapidly be aligned by this method. Wind turbine According to the invention a wind turbine blade is provided or prepared. Such wind turbine blades are used for wind turbines for energy production, either directly into electrical energy or for an energy storage where the energy is stored as chemical energy or as potential energy. Features interchangeable between embodiments An individual feature or combination of features from an embodiment of the invention described herein, as well as obvious variations thereof, are combinable with or exchangeable for features of the other embodiments described herein, unless the person skilled in the art would immediately realise that the resulting embodiment is not physically feasible. The term "comprising" as used in this specification means "consisting at least in part of. When interpreting each statement in this specification that includes the term "comprising", features other than that or those prefaced by the term may also be present. Related terms such as "comprise" and "comprises" are to be interpreted in the same manner. intellectual property office of n z 3 0 OCT 2009 received WO 2006/070171 555904 17 PCT/GB2004/005433 TABLE OF IDENTIFICATION 2 Wind turbine blade shell member 4 Fastening member 6 Root end of wind turbine blade 5 8 Pre-fabricated sticks 10 Pre-fabricated sticks comprising fibrous material 12 Part of fastening member to be embedded 14 Outer rigid mould 16 Inner mould 10 18 Fibre layer 19 Gel coat 20 Guiding means 21 Woven fibres 22 Lightning conductor 15 24 Lightning transfer means 30 Rod extending from fastening member 32 Hole in a fastening member 34 Recess 36 Protrusion 20 38 Rubber-like element </div>

Claims

<div class="application article clearfix printTableText" id="claims"> 555904 18 WHAT WE CLAIM IS:

1. A method of manufacturing a wind turbine blade shell member with a fastening member provided near a root end of the wind turbine blade shell member, the fastening member being suitable for connecting a wind turbine blade comprising said wind turbine blade shell member to a wind turbine hub, the method comprising the steps of: providing a rigid outer mould; positioning the fastening member near the end of the rigid outer mould corresponding to the root end of the wind turbine blade; positioning at least two layers of pre-fabricated sticks near the end of the rigid outer mould corresponding to the root end of the wind turbine blade such that prefabricated sticks surround a substantial longitudinal part of the fastening member when the fastening member is positioned in the wind turbine blade shell member; positioning one or more layers of pre-fabricated sticks in a substantial longitudinal part of the rigid outer mould; thereafter providing an inner mould in vacuum-tight connection with the rigid outer mould; evacuating the volume between the outer and the inner moulds, infusing a curable resin to secure the fastening member to the enclosing pre-fabricated sticks and substantially fil! empty space between adjacent sticks, and allowing the resin to cure; de-moulding the wind turbine blade shell member.

2. A method of manufacturing a wind turbine blade shell member according to claim 1, wherein the pre-fabricated sticks adjacent to the fastening member are shaped to conform to the shape of the fastening member such that a substantial part of the fastening member is tightly enclosed by the pre-fabricated sticks. intellectual property OFFICE OF N.Z. 3 0 OCT 2009 received .doc 555904 19

3. A method of manufacturing a wind turbine blade shell member according to claim 1 or 2, wherein the overall shape of the fastening member is generally conical with a larger part pointing into the wind turbine blade shell member.

4. A method of manufacturing a wind turbine blade shell member according to any one of the claims 1 to 3, wherein the overall shape of the fastening member is concave.

5. A method of manufacturing a wind turbine blade shell member according to any one of the claims 1 to 4, wherein the overall shape of the fastening member is generally dumbbell-shaped.

6. A method of manufacturing a wind turbine blade shell member according to any one of the claims 1 to 5, wherein the fastening member comprises a part with a non-circular cross section orthogonal to the longitudinal direction of the fastening member.

7. A method of manufacturing a wind turbine blade shell member according to any one of the claims 1 to 6, wherein the fastening member is provided with microscopic surface roughness comprising irregularities in the micrometers to millimetre range.

8. A method of manufacturing a wind turbine blade shell member according to claim 7, wherein the irregularities in the microscopic surface roughness are in the range of 10 pm to 1 mm.

9. A method of manufacturing a wind turbine blade shell member according to any one of the claims 1 to 8, wherein the fastening member is provided with macroscopic surface roughness, comprising a plurality of recesses and protrusions in the millimetre to centimetre range.

10. A method of manufacturing a wind turbine blade shell member according to claim 9, wherein the recesses and protrusions are in the range of 1 mm to 5 cm.

11. A method of manufacturing a wind turbine blade shell member according to any one of the claims 1 to 10, wherein at least some of the prefabricated sticks are selected from the group of fibrous members. intellectual property OFFICE OF N.Z. 3 0 OCT 2009 received 555904 20

12. A method of manufacturing a wind turbine blade shell member according to claim 11 wherein the group of fibrous members includes pultruded or extruded, partially or fully cured members.

13. A method of manufacturing a wind turbine blade shell member according to claim 11 or claim 12 wherein the group of fibrous members includes carbon fibres and/or glass fibres; wooden material; and hollow members.

14. A method of manufacturing a wind turbine blade shell member according to claim 13 wherein the wooden material comprises balsa, birch or other material comprised in plywood.

15. A method of manufacturing a wind turbine blade shell member according to any one of the claims 1 to 14 wherein at least one prefabricated stick comprising fibrous material, extends to near the root end of the wind turbine blade shell member.

16. A method of manufacturing a wind turbine blade shell member according to claim 15, wherein the fibrous material comprises carbon fibres.

17. A method of manufacturing a wind turbine blade shell member according to any one of the claims 1 to 16, wherein at least one prefabricated stick comprising fibrous material is positioned adjacent to the fastening member along a substantial longitudinal part of the fastening member.

18. A method of manufacturing a wind turbine blade shell member according to claim 17 wherein the pre-fabricated stick comprising fibrous material is pultruded and comprises carbon fibres.

19. A method of manufacturing a wind turbine blade shell member according to claim 17 or claim 18, wherein at least two pultruded fibrous members are positioned adjacent to the fastening member and along a substantial longitudinal extent of the fastening member.

20. A method of manufacturing a wind turbine blade shell member according to claim 19 wherein the pultruded fibrous members are arranged around the fastening member such that the arrangement is substantially symmetrical with regard to one or more physical property. 2t96M0J.doc Wre0mcE0FP?ga«* 3 0 OCT 2009;Receiv e d;555904;21;

21. A method of manufacturing a wind turbine blade shell member according to claim 20 wherein the physical property is stiffness, E-modulus, alignment or ultimate strength.;

22. A method of manufacturing a wind turbine blade shell member according to any one of the claims 1 to 21, further comprising the step of applying a surface material to the mould; and/or applying a lightning conductor, and/or a layer comprising fibre material.;

23. A method of manufacturing a wind turbine blade shell according to claim 22, wherein the surface material is a gel coat.;

24. A method of manufacturing a wind turbine blade shell according to claim 22 wherein the lightning conductor is a metal mesh and/or a lightning conductor cable.;

25. A method of manufacturing a wind turbine blade shell according to claim 22 wherein the fibre material is glass fibres or carbon fibres.;

26. A method of manufacturing a wind turbine blade shell member according to any one of the claims 1 to 25, further comprising the step of temporarily connecting the fastening member to a guiding means for aligning the fastening member relative to at least one further fastening member and/or for aligning the fastening member relative to the rigid outer mould during at least one step of the method of manufacturing.;

27. A method of manufacturing a wind turbine blade shell member according to claim 26, wherein said further fastening member is temporarily connected to a guiding means.;

28. A method of manufacturing a wind turbine blade shell as claimed in claim 27, wherein the further fastening member is temporarily connected to the same guiding means as the fastening member.;

29. A method of manufacturing a wind turbine blade shell member according to any one of the claims 26 to 28 further comprising the step of releasing the temporary connection between the fastening member and the guiding means.;

30. A method of manufacturing a wind turbine blade shell according to claim 29 further comprising the step of removing the guiding means from the wind turbine blade shell member.;555904;22;

31. A method of manufacturing a wind turbine blade shell member according to any one of the claims 26 to 30, wherein the guiding means is generally gas impermeable and the guiding means may be arranged to provide a gas tight connection between the guiding means and at least one of the moulds.;

32. A method of manufacturing a wind turbine blade shell member according to any one of the claims 26 to 31, wherein the temporary connection of the fastening member to the guiding means involves engaging a threaded hole or a threaded rod of the fastening member with a bolt or a nut via a hofe in the guiding means.;

33. A method of manufacturing a wind turbine blade shell member according to claim 32 wherein the threaded hole or rod of the fastening member is suitable for connecting a wind turbine blade comprising a wind turbine shell member to the wind turbine hub.;

34. A method of manufacturing a wind turbine blade shell member according to any one of the claims 26 to 33, wherein the temporary connection of the fastening member to the guiding means is gas tight.;

35. A method of manufacturing a wind turbine blade shell member according to claim 34 wherein the gas tight connection comprises an O-ring.;

36. A method of manufacturing a wind turbine blade shell member according to any one of the claims 1 to 35, further comprising the step of arranging a lightning conductor in potential equalising communication with the fastening member.;

37. A method of manufacturing a wind turbine blade shell member according to claim 36, wherein the lightning conductor is in potential equalising communication with the fastening member adjacent to the root end of the wind turbine blade shell member.;

38. A method of manufacturing a wind turbine blade shell member according to claim 36 or 37, wherein the potential equalising communication involves providing a lightning transfer means for decreasing the contact resistance between the fastening member and the lightning conductor.;

39. A method of manufacturing a wind turbine blade shell member according to claim 38 wherein decreasing the contact resistance between the fastening member and the lightning conductor is provided by an increased contact area.;intellectual property;OFFICE OF N.Z;3 0 OCT 2009;received;< »;555904;23;

40. A method of manufacturing a wind turbine blade shell member according to any one of the claims 36 to 39, wherein the potential equalising communication involves carbon fibres.;

41. A method of manufacturing a wind turbine blade shell member according to claim 40 wherein the carbon fibres are comprised of carbon fleece, a carbon fibre web, or a carbon fibre mat.;

42. A method for manufacturing a wind turbine blade comprising securing a wind turbine blade shell member manufacturable by the method according to any one of the claims 1 to 39 to at least one further turbine blade shell member to form a wind turbine blade, said securing comprising chemical means, or mechanical means.;

43. A method of manufacturing a wind turbine blade according to claim 42 wherein the wind turbine shell member manufacturable by the method according to any one of claims 1 to 39, is secured to further elements.;

44. A method of manufacturing a wind turbine blade as claimed in claim 43 wherein the further elements include a spar or a spacer element.;

45. A method of manufacturing a wind turbine blade according to any one of claims 42 to 44 wherein the chemical means comprise an adhesive.;

46. A method of manufacturing a wind turbine blade according to any one of claims 42 to 45 wherein the mechanical means includes fasteners.;

47. A method for manufacturing a wind turbine blade comprising securing a multiplicity of wind turbine blade shell members manufactured by the method according to any one of the claims 1 to 39 such that fastening members from at least two wind turbine blade shell members are aligned.;

48. A method for manufacturing a wind turbine blade according to claim 47 wherein the fastening members are aligned by aligning guiding means corresponding with each wind turbine blade shell member.;I 3 0 OCT 2009;[RECEIVf nj;219604H_>-*>c 555904 24

49. A wind turbine blade comprising a wind turbine blade shell member with pre-fabricated sticks connected by a cured resin, and a plurality of fastening members embedded near a root end of the wind turbine blade, at least two of said fastening members being aligned to facilitate connection to a wind turbine hub, wherein the pre-fabricated sticks adjacent to the fastening member conform to the shape of the fastening member such that a substantial part the fastening member is tightly enclosed by the pre-fabricated sticks.

50. A wind turbine blade according to claim 49, wherein the general overall shape of the fastening member is generally conical with a larger part oriented away from the root end of the wind turbine blade into the wind turbine blade shell member.

51. A wind turbine blade according to any one of the claims 49 to 50, wherein the overall shape of the fastening member is concave.

52. A wind turbine blade according to any one of the claims 49 to 50, wherein the overall shape of the fastening member is generally dumbbell-shaped.

53. A wind turbine blade according to any one of the claims 49 to 52, wherein the fastening member comprises a section with a non-circular cross section orthogonal to the longitudinal direction of the fastening member.

54. A wind turbine blade according to any one of the claims 49 to 53, wherein the fastening member has a microscopic surface roughness comprising irregularities in the micrometre to millimetre range.

55. A wind turbine blade according to claim 54, wherein the irregularities in the microscopic surface roughness are in the range of 10 pm to 1 mm.

56. A wind turbine blade according to any one of the claims 49 to 55, wherein the fastening member has a macroscopic surface roughness, comprising a plurality of recesses and protrusions in the millimetre to centimetre range. lOTELLECTUAL PROPERTY OFFICE OF N.Z. 3 0 OCT 2009 [received 555904 25

57. A wind turbine blade according to claim 56 wherein the macroscopic roughness of the fastening member is in the range of 1 mm to 5 cm.

58. A wind turbine blade according to any one of the claims 49 to 58, further comprising a lightning conductor in potential equalising communication with the fastening member.

59. A wind turbine blade according to claim 58, wherein the lightning conductor is in potential equalising communication with the fastening member adjacent to the root end of the wind turbine blade shell member.

60. A wind turbine blade according to claim 58 or 59, wherein the potential equalising communication comprises a lightning transfer means for decreasing the contact resistance between the fastening member and the lightning conductor.

61. A wind turbine blade according to claim 60, wherein means for decreasing the contact resistance between the fastening member and the lightning conductor is by providing an increased contact area.

62. A wind turbine blade according to any one of the claims 58 to 61, wherein the potential equalising communication involves carbon fibres.

63. A wind turbine blade according to claim 62 wherein the carbon fibres are carbon fibre fleece, carbon fibre web, or a carbon fibre mat.

64. A wind turbine blade according to any one of the claims 49 to 61, wherein the fastening member comprises a threaded surface for connecting to a guiding means during manufacturing of the wind turbine blade shell member, said threaded surface part is suitable for use in the connection of a wind turbine blade comprising the wind turbine shell member to the wind turbine hub.

65. A wind turbine blade according to any one of the claims 49 to 64, further comprising a surface material, and/or a lightning conductor, and/or a layer comprising fibre material.

66. A wind turbine blade according to claim 65, wherein the surface material is a gel coat. 21%»>40 l.doc 3 0 OCT 2009 ■i^ElVED I 555904 26

67. A wind turbine blade according to claim 65 or 66, wherein the lightning conductor is a metal mesh and/or a lightning conductor cable.

68. A wind turbine blade according to any one of claims 65 to 67, wherein the layer comprising fibre material comprises glass fibres or carbon fibres.

69. A wind turbine blade according to any one of the claims 49 to 68 wherein at least one prefabricated stick comprising fibrous material extends to near the root end of the wind turbine blade shed member.

70. A wind turbine blade according to claim 69 wherein the prefabricated stick comprising fibrous material comprises carbon fibres.

71. A wind turbine blade according to any one of the claims 49 to 70, wherein at least one prefabricated stick comprising fibrous material is positioned adjacent to the fastening member along a substantial longitudinal part of the fastening member.

72. A wind turbine blade according to claim 71 wherein the at least one prefabricated stick comprises carbon fibres.

73. A wind turbine blade according to claims 71 or 72 wherein the prefabricated stick comprises fabrious material and is pultruded.

74. A wind turbine according to any one of claims 71 to 73, wherein at least two pultruded fibrous members, are positioned adjacent to the fastening member (4) and along a substantial longitudinal part of the fastening member.

75. A wind turbine blade according to claim 74 wherein the at least two pultruded fibrous members contain carbon fibres.

76. A wind turbine blade according to claims 74 or 75 wherein the pultruded fibrous members are arranged around the fastening member such that the arrangement is substantially symmetrical with regard to one or more physical property.

77. A wind turbine blade according to claim 76 wherein the physical property is one of stiffness, E-modulus, alignment or ultimate strength. 2mii4s)J.Joc intellectual property OFFICE OF IW Z 3 0 OCT 2009 received 1 555904 27

78. A wind turbine comprising a wind turbine blade according to any one of the claims 49 to 71, and/or a wind turbine blade comprising a wind turbine blade she!) member manufactured by a method according to any one of the claims 1 to 39, and/or a wind turbine blade manufactured by a method according to any one of the claims 42 or 48.

79. Use of a wind turbine according to claim 78 for energy production or energy storage.

80. A guiding means for aligning a fastening member relative to at least one further fastening member and/or for aligning the fastening member relative to the rigid mould, during resin transfer moulding of a wind turbine blade shell member, comprising a generally gas tight plate-like member; a means for obtaining an at least temporary connection between the gas tight plate-like member and at least one fastening member; and a means for obtaining an at least temporary connection between the generally gas tight plate-like member and a rigid outer mould; wherein at least one of said at least temporary connections are gas tight, such that the guiding means are suitable for vacuum-assisted resin transfer moulding.

81. A guiding means for aligning a fastening member relative to at least one further fastening member and/or for aligning the fastening member relative to the rigid mould, during resin transfer moulding of a wind turbine blade shell member as claimed in claim 80, wherein at least both temporary connections are gas tight.

82. A subassembly for a wind turbine blade shell member comprising a plurality of fastening members connected to a guiding means according to claim 80 or 81, wherein the fastening members are aligned. i 3 0 OCT 2009 i [ft e c eIV c [J 219604O_l.doc 555904 28

83. A subassembly for a wind turbine blade shell member according to claim 82, wherein the fastening members are aligned substantially in parallel.

84. A subassembly according to claim 82 or 83 further comprising fibres woven about at least two of the fastening members.

85. A subassembly according to claim 84 wherein the fibres are dry or impregnated fibre tows, yams or another collection of fibres.

86. A method of manufacturing a wind turbine blade shell member, substantially as herein described with reference to the accompanying drawings.

87. A wind turbine blade, substantially as herein described with reference to the accompanying drawings.

88. A guiding means for aligning a fastening member relative to at least one further fastening member and/or aligning the fastening member relative to the rigid mould, during resin transfer moulding of a wind turbine blade shell member, substantially as herein described with reference to the accompanying drawings. VESTAS WIND SYSTEMS A/S By thejatith^rised agents A J P/ Per: 21 I40_l.doc ll,nEW§CEAOFTiERTY] 3 0 OCT 2009 received </div>