FORM 2
THE PATENTS ACT, 1970 (39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10, Rule 13]
METHOD OF MANUFACTURING SHEAR WEB CORE TEMPLATE AND AN APPARATUS THEREFOR;
SU2L0N ENERGY LIMITED, A COMPANY
INCORPORATED UNDER THE COMPANIES
ACT, 1956, WHOSE ADDRESS IS UNIT NO.
6, BLOCK NO. 93, VILLAGE: VADASALA-
VARNAMA, N.H.NO.8, DISTRICT
VADODARA -391242, GUJARAT, INDIA
THE FOLLOWING SPECIFICATION
PARTICULARLY DESCRIBES THE
INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED.

Field of invention:
The present invention relates to shear webs of the wind turbine and more particularly to a web core of the shear web.
Background of the invention:
Turbine blades are important elements of the wind turbines that are used to convert wind energy into electrical energy. These blades have cross sectional profile of an airfoil such that, air flowing over the blade produces pressure difference along the sides of the blades during the operation. As a result a lift force acts on the blade which is directed from a pressure side towards a suction side. The lift force generates torque on the main rotor shaft that is geared with the generator for producing electricity.
An example of prior art wind turbine blade 100 is shown in FIG. 1. The wind turbine blade 100 typically includes a pressure side, a suction side, a root, a tip, a leading edge, a trailing edge, a pressure side spar, a suction side spar, a leading edge side shear web and a trailing edge side shear web. The wind blade narrows down in its profile from the root to the tip due to which a shear web 102 positioned within the blade 100 also reduces in size from the root to tip in terms of pressure side to suction side.
The turbine blades typically consist of a pressure side shell and a suction side shell that are made of glass fibre reinforcements & core. These shells are bonded together at bonding lines, particularly along the trailing and leading edges of the blade. In addition, the turbine blades include one or even more internal shear webs arranged in parallel manner and which extend between the pressure side and the suction side of the turbine

blade. These shear webs are bonded to the spar caps that are affixed to the inner faces of the shell wherein the shear web preferably has a longitudinal extension to the length of blade.
It is well-known practice to make use of flange for achieving a desired bond width for the bond paste applied between the spar cap and transverse ends of the shear web. The transverse ends of the shear web flange profile matches with the profile of inner surface of the shells on which the flanges are glued with the paste. Generally, both the flanges of shear web are neither identical with each other nor identical from section to section. Normally, the shear web has C-shaped configuration because the flanges are at transverse ends. However, the shear web flanges do not extend at 90°, but their angles vary from section to section due to profile of the blade.
For example, referring to FIGS. 2a- 2b, a traditionally known shear web product 200 is shown. The shear web product 200 has a pressure side flange 202 and a suction side flange 204 as shown. The flanges 202, 204 are used to facilitate bonding with the shells. The flanges 202, 204 are bigger in height than shear web thickness. A core 206 is shown that has a thickness which is uniform from the pressure side flange 202 to the suction side flange 204 such that the core touches to ends of the flanges 202, 204 in this one example. It can be seen that the flanges 202, 204 are not perpendicular. In addition, it can also be seen that the flange angle on the pressure side flange 202 is different from that of suction side flange 204. It can be also seen that section to section angles of pressure side flange 202 and suction side flange 204 are not similar.

Another example, referring to FIG. 3a, 3b, another traditionally know shear web product 300 is shown. The shear web product 300 is having a pressure side flange 302 and a suction side flange 304 as shown. It can be seen that the shear web is not straight and the thickness of shear web product 300 is not uniform from the pressure side flange 302 to the suction side flange 304. In this example, it can be seen that a core 306 does not touch to the ends of the flanges 302, 304. Also, it can be seen that the flanges 302, 304 are bigger in height than the thickness of the shear web. It can be seen that the flanges 302, 304 are not perpendicular. In addition, it can also be seen that the flange angle on the pressure side flange 302 is different from that of suction side flange 304. It can be also seen that section to section flange angles are not similar on pressure side 302 and suction side 304.
Referring now to FIG. 4, a shear web mould 400 that is traditionally used to manufacture the shear web is shown whose top view profile looks identical to the shear web product as shown in FIGS. 2a, 2b, 3a and 3b. The web mould 400 has a width that is similar to the width of the web product on the pressure side and suction side and is similar with web mould. The height of web mould flange is more by some millimetres than web product. However, the web flanges profiles throughout the length are similar with the inner skin profile of shell on which flanges are being glued. This makes the bottom width of the web product and mould identical which goes on increasing towards the flange.
Prefabrication of these shear webs is generally done on a separate mould by following a sequence wherein some of the glass fibre reinforcement layers are initially placed on

which some thickness of core is positioned and finally some of the glass fibre reinforcement layers are positioned. These reinforcement layers are held together using techniques such as VARTM, hand layup and the like. Core manufacturers normally supply core pieces having fix length and width. However, the shape of core pieces those used in web prefabrication are not of same shape as each core piece is different from other. Hence, it becomes a prime concern to shape the core pieces as per the web mould. Referring to FIG. 5, top view of core pieces those covered shear web are shown for example. These core pieces shape may be as per section B-B in FIG. 2b or section A-A in FIG 3b.
However, shear web profile narrow down from start to end thereby making core preparation extremely difficult to fit well within the web mould due to varying angle in web flanges. In addition, the manufacturers of the shear web mainly use of the paper templates to manually make the core as per the web mould. However, the process of manually shaping the core material per web mould design is extremely difficult and moreover inaccurate due to varying angles of the web flanges. In addition, thickness of the core material adds in more difficulty in shaping the core material. Hence, the process of manual shaping of the core material requires substantial human efforts thereby making it more complex. In addition, the process of manual shaping is extremely lengthy and time consuming. For example, the process of core making requires handling of the core from one place to another and needs markings to be done on the core. In such instance, chances of error in making markings result in wrong cutting of core that further results into mismatch In the web mould of core. This can

only be corrected by replacement of the core if the core becomes smaller or reworked if the core becomes bigger. The process of manual shaping of the core material affects on wrong fitment of core in web mould resulting in resin accumulation in web product thereby resulting in repairing of the web.
Accordingly, there exists a need of a template designing method for accurate manufacturing of core pieces thereby considering varying angles of web flanges. Also, there exists a need of a template designing apparatus that provides templates in a faster manner thereby saving the template making time.
Objects of invention
An object of the present invention is to provide a template designing process for accurate manufacturing of core pieces.
Another object of the present invention is to provide an apparatus that assists in the template designing process for manufacturing templates without any actual measurement thereof.
Summary of the invention
In accordance with the present invention a template designing process and an apparatus adapted therefor is disclosed wherein a template is designed to give shape to a core as per web mould thereof. The template of the present invention includes two top and bottom profiles that are made of meta! or glass fibre laminates or combination or any other material thereof. The two top & bottom profiles respectively have shapes of the

top and bottom of each core piece that are formed using CAD profiles. The top and bottom profiles are joined via a core or any other material piece whose thickness is same as that of a readymade core piece which needs to be shaped per the web mould. The present invention may include a template location identification configured on a surface thereof. The top and bottom profiles are joined on top of each other by keeping a particular distance in between such that the particular distance defines a thickness of the readymade core that needs to be shaped using the template.
According to an alternative embodiment of the present invention, a reverse engineering method for making templates is disclosed. In a first step, a well-fit readymade core piece that fits well in a web mould is selected. Subsequently, the well-fit readymade core piece is taken out from the web mould and the laminates from fibre or metal or combination or any other material are made more in length & width by considering the top and bottom dimensions of the well-fit readymade core piece. Further, the laminates or metal or combination or any other material thus prepared are separated from each other by positioning and gluing a core or any other material piece of same thickness as that of the well-fit readymade core piece used for making the template. Further, the width of the templates is reduced at the area using a trimming/grinding operation. The trimming/grinding operation is performed on a clamping apparatus to obtain a final template in this one alternative embodiment. In next step, a remaining space of the web mould where core pieces are positioned is converted on to templates by considering respective top and bottom profiles of the web mould.

The present invention is applicable for shear web core preparation but also can be used for applications except shear web core preparation. The present invention is applicable for making of any article by using the template whose start width is not similar to end width and top shape is smaller or bigger than bottom shape in terms of chamfer and which has some thickness as well.
Brief description of the drawings
FIG. 1 is a perspective view of a prior art wind turbine blade; FIG. 2a is a top view of a first type of prior art shear web product;
FIG. 2b is a cross-sectional view taken along line B-B of the shear web product of FIG.
2a;
FIG. 3a is a top view of a second type of prior art shear web product;
FIG. 3b is a cross-sectional view taken along line A-A of the shear web product of FIG. 3a;
FIG. 4 is a front view of a prior art shear web mould;
FIG. 5 is a top view of a prior art shear web covered with a plurality of core pieces thereon;
FIG. 6a is a first section profile mapped using CAD that has a thickness of shear web core that is not uniform from a pressure side to a suction side;

FIG. 6b is a second section profile mapped using CAD that has a thickness of shear web core that is uniform from a pressure side to a suction side;
FIG. 7a is a top view of a first laminate having dimensions of a top profile of the core piece made in CAD;
FIG. 7b is atop view of a second laminate having dimensions of a bottom profile of the core piece made in CAD;
FIG. 8a is front view of a core piece adapted to be positioned between the first and second laminates;
FIG. 8b is a top perspective view of the core piece of FIG. 8a;
FIG. 9a shows a first step of the template making method in accordance with the present invention;
FIG. 9b shows a next step of the template making method of FIG. 9a;
FIG. 9c shows a next step of the template making method of FIG. 9b;
FIG. 9d shows a last step of the template making method of FIG. 9c;
FIG. 10a shows a first step of a core piece making process using the template of FIG. 9d:
FIG. 10b shows a next step of the core piece making process of FIG. 10a;
FIG. 10c shows a further step of the core piece making process of FIG. 10b;

FIG. lOd shows a next step of the core piece making process of FIG. 10c;
FIG. lOe shows a last step of the core piece making process of FIG. lOd;
FIG. 11 is a top perspective view of an alternative embodiment of the template in accordance with the present invention;
FIG. 12 is a perspective view of another alternative embodiment of the template in accordance with the present invention;
FIG. 13 shows a Iayup of core pieces in the shear web mould is shown;
FIG. 14a shows a first step of an alternative template designing process per a reverse engineering method;
FIG, 14b shows a next step of the template designing process per the reverse engineering method of FIG. 14a; and
FIG. 14c shows a final step of the template designing process per the reverse engineering method of FIG. 14b.
Detailed description of the invention:
The foregoing objects of the present invention are accomplished and the problems and shortcomings associated with the prior art, techniques and approaches are overcome by the present invention as described below in the preferred embodiments.
In accordance with the present invention, a template designing process and an apparatus adapted therefor is disclosed wherein two templates per core piece are made for giving

shape to the core as per web mould which includes two metal or glass/fibre laminate or combination or any other material followed by joining thereof by having a core or any other material piece there between whose thickness is same as of core piece that needs to be shaped per a web mould.
In a preferred embodiment, the present invention provides a template designing process using a CAD profile wherein top and bottom profiles of each core piece are drawn on the CAD that fits well in a web mould. Simultaneously, laminates of fibre glass or any other material are made and subsequently laminates are cut per CAD drawings. These laminates are preferably joined by positioning a small piece of core material there between and gluing the same along one edge of these laminates. It is understood here that the thickness of the piece is identical to a thickness of the web core used in shear web. The purpose of gluing the core piece to both laminates is for alignment of both templates to each other at particular location. The same process can be used to make the templates for the remaining core pieces.
In this one preferred embodiment, the template designing process using the CAD profile comprising steps of:
a) Drawing top and bottom profiles of each core piece are drawn on the CAD which fits well in a web mould;
b) Making straight laminates that are having same dimensions as that of top and bottom profiles of the core pieces those made in CAD;

c) Making top and bottom laminates more in length than CAD top and bottom profile for fixing and aligning member as core piece with both laminates.
d) Selecting a core or any other material piece having a thickness that is same to a thickness of the web core used in web prefabrication;
e) Positioning the core piece in between the laminates followed by permanent joining thereof to form a template of the present invention;
f) Positioning a readymade web core piece within the template obtained in step e) thereby aligning the readymade web core piece with the core piece of the template; and
g) Trimming and cutting the readymade web core piece along the edges of the template to obtain the web core fitting well within a web mould.
The detailed method or process of design templates using CAD profile and making of well cut core using the same is described hereinafter:
Referring to FIGS. 6a-6b, one of the core pieces are selected whose top and bottom section profiles are mapped using CAD such as for example a first section profile 610 and a second section profile 620 in this one embodiment. The first section 610 has a thickness of shear web core that is not uniform from pressure side to suction side wherein the core not touches to end of mould flange. The second section 620 is showing thickness of shear web core that is uniform from pressure side to suction side wherein core touches to mould flange end.

Referring to FIG. la-lb, a first laminate 710 and a second laminate 720 are respectively shown that are preferably made in a next step of the template designing process wherein the laminates are having same dimensions as that of top and bottom profiles of the core pieces those are made in CAD. In this one embodiment, the laminates 710, 720 are preferably made of fiber glass material. However, it is understood that the laminates 710, 720 can be made of other materials in alternative embodiments of the present invention. The laminates 710, 720 have same dimensions of the top and bottom profile of the core pieces those made in CAD and shown in FIGS. 6a-6b. The laminates 710, 720 have extra lengths that may be either at root side or at tip side or at both sides for sticking the small core piece to align the both top and bottom laminates 710, 720 as per design thereof.
Referring now to FIGS. 8a-8b, a core piece 810 in accordance with the present invention is shown. The core piece 810 has a length that is sufficient enough to join the laminates 710, 720 at root or tip or at both. The extra length of the laminates 710, 720 is adapted to facilitate gluing of the core piece in between the laminates 710, 720. The core piece 810 has a thickness is same to a thickness of a web core used in web prefabrication.
Referring now to FIGS. 9a- 9d, a preferred method of positioning the core piece 810 in between the laminates followed by permanent joining thereof to form a template 900 is shown.

In this one embodiment, the laminates 710, 720 are joined at root side thereof. In an initial step, a thin layer of glue or adhesive 910 is applied on the bottom laminate 710. In next step, the core piece 810 is positioned on the glued area of the bottom laminate 710. In next step, a thin layer of glue or adhesive 920 is applied on a top surface of the core piece 810 on which the top laminate 720 is stuck to form the template 900 in accordance with the present invention. It is understood here that template 900 can be made by joining metal or glass/fibre laminate or combination or any other material with core or any other material. Here the portion of both top and bottom laminates 710, 720 used for gluing the core 810 is extra than the core piece for which templates is made.
Referring to FIGS. 10a- lOd, a process of making the core piece using template 900 is shown. Whenever prefabrication is required, a readymade core piece or foam 1000 procured from the manufacturer is placed in between the laminates 710, 720 such that the readymade core piece 1000 is touched and aligned along the core piece 810 positioned within the laminates 710, 720.
As shown in FIGS. lOb-lOc, a clamping apparatus 1010 is adapted that is operable between a first open position and a second closed position as illustrated respectively. The template 900 is having positioned with the readymade core piece 1000 is adapted to be placed on the clamping apparatus 1010. The clamping apparatus 1010 includes a first clamping arm 1020 and a second clamping arm 1030 that prevent displacement of the core piece 1000 and template 900 thereby firmly holding them in the clamping apparatus 1010. Subsequently, as shown in FIG. lOd, excess core piece 1000 is cut or trimmed using a trimming tool 1030 by considering profile of edges of the end

laminates 710, 720, Accordingly, as shown in FIG. lOe, a well cut core 1040 is obtained that is placed in the web mould above bottom layer thereof and well fitting of the core in the web mould is observed. Similarly, more core pieces can be made as per web mould by using numbers of multiple templates.
Referring to FIG. 11. an alternative embodiment of template is shown. In this alternative embodiment, a template 1100 is designed such that edges of the laminates 710, 720 are covered by a protecting material which protects edges of the templates from sanding and grinding during the operation. In this one particular embodiment, edges of the template 710 are protected by thin metal sheet segments 1110, 1120 and 1130. Also, the edges of the template 720 are protected by thin metal sheet segments 1140, 1150 and 1160. However, it is understood that thin metal segments 1120 and 1150 may not be present in other alternative embodiments of the laminates 710, 720.
As shown in FIG. 12, another alternative embodiment of template is shown. In this alternative embodiment, the template 1200 has a first edge 1210. The first edge 1210 has a tapered configuration that is adapted to nearer to the web mould flange profile in this one alternative embodiment. The template 1200 has a second edge 1220. The second edge 1220 has a straight configuration that touches to the core piece which is adapted to be used as it is in the web mould.
Referring to FIG. 13, a layup of core pieces 1300 in the shear web mould is shown. If width of core piece is smaller than web mould width then more than one core piece is used to cover the web width from suction side flange to pressure side flange. If this is

the case then, core from core manufacturer are used as it is at centre of width of web and remaining width is occupied by small pieces of core pieces whose location is at both flange sides. Because of above mentioned process, making of big template from suction side flange to pressure side flange is eliminated. This results saving of the core material in template making and moreover handling of template becomes easy. This also facilitates the clamping apparatus 1010 of smaller size.
Referring to FIGS. 6a- 13, the above-mentioned process of core making has one or more of the following advantages. The process of core making is very simple in operation. The process of core making substantially reduces core making time. The process of core making does not need to take any measurement of the core. The process of core making prevents need of making markings on the foam. The process of core making prevents extensive handling of the core during the use. The above-mentioned process of core making reduces human efforts. The process of core making makes core to seat well in web mould as per requirement due to which it eliminates core modification or replacement which avoid wastage. The process of core making eliminates resin accumulation thereby preventing non conformity and resulting in saving time in repairing.
In an alternative embodiment, the present invention provides a reverse engineering method that is useful when templates made by using CAD profile followed by making core pieces therefrom do not seat well in the web mould.

In this one alternative embodiment the reverse engineering method includes the steps of:
a) Setting the core pieces well in web mould by a trial and error method followed by checking fitment thereof in a web mould followed by removal thereof;
b) Making the straight laminates for bigger sizes than the core pieces;
c) Permanently joining both the laminates at root or tip or both side by means of core piece which needs to be used in web prefabrication;
d) Placing the core piece which fits well in web mould in between the laminates thereby aligning the core piece to the core piece edge which join the laminates; and
e) Holding the core piece and the template in the clamping apparatus followed by
sanding the laminates such that the laminates take the shape of exact core
thereby forming a final template.
The detailed method or process of design templates using the reverse engineering method is described hereinafter:
Referring FIG. 14a, a core piece 1410 that fits well in the web mould is selected and is positioned between an opposed pair of laminates 1420, 1430 in a first step. In this step, a clamping apparatus 1400 is utilized on which the core piece 1410 is aligned with a prepositioned core piece 1440 between the templates 1420, 1430. It is understood here that the prepositioned core piece 1440 is merely used for gluing and align the laminates with each other.

As shown in FIG. 14b, the laminates 1420, 1430 are observed to be totally enclosing the core piece 1410 in next step. In this step, a trimming tool 1450 is utilized to trim or grind the edges of the laminates 1420, 1430 such that the edges thereof are observed to be aligned with the core piece 1410 to obtain a final template as shown in FIG. 14c. In next step, the final template such obtained is used for serial product web core preparations by using the web core making process described in detail in FIGS. 10a-iOe.
The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the present invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching.
The embodiments were chosen and described in order to best explain the principles of the present invention and its practical application, to thereby enable others, skilled in the art to best utilize the present invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omission and substitutions of equivalents are contemplated as circumstance may suggest or render expedient, but such are intended to cover the application or implementation without departing from the spirit or scope of the present invention.

We claim:
J. A template designing process using the CAD profile followed by utilizing the template for web core preparation, the template designing process comprising steps of:
a) Drawing top and bottom profiles of each core piece are drawn on the CAD which fits well in a web mould;
b) Making straight laminates that are having same dimensions as that of top and bottom profiles of the core pieces those made in CAD;
c) Making top and bottom laminates that are more in length than CAD top and bottom profile in order to fix and align member as core piece with both laminates.
d) Forming a template by utilizing the laminates in step c);
e) Positioning the template obtained in step d) on a trimming apparatus along with a readymade web core piece positioned therein; and
f) Trimming and cutting of the readymade web core piece on the clamping apparatus as per the shape of the template thereby obtaining a well-fit web core.
2. The template designing process as claimed in claim 1, wherein the laminates are made of a material selected from a group consisting of metal, glass laminate, fibre laminate and/or a combination thereof.

3. The template designing process as claimed in claim 1, wherein the template includes a template location identification configured on a surface thereof.
4. The template designing process as claimed in claim 1, wherein the template includes a core or any other material piece positioned therein.
5. The template designing process as claimed in claim 4, wherein the core piece has a thickness that is equivalent to a thickness of the readymade web core piece.
6. The template designing process as claimed in claim 1, wherein the laminates are permanently connected to the core piece.
7. The template designing process as claimed in claim 1, wherein the readymade web core piece is axially aligned along the core piece.
8. The template designing process as claimed in claim 1, wherein the clamping apparatus includes a pair of clamping arms that firmly hold the core piece and template to prevent displacement thereof.
9. The template designing process as claimed in claim 1, wherein the template has dimensions that are reduced at area where building height of shear web from pressure side to suction side is more than readymade core dimensions.
10. The template designing process as claimed in claim 1, wherein the templates are made for the core pieces that are nearer to a mould flange such that the readymade core pieces are laid down at the center of web width in an original shape thereof.

11. The template designing process as claimed in claim 1, wherein the templates are made for the core pieces those are little inside from pressure and suction side web mould flange.
12. The template designing process as claimed in claim 1, wherein the templates are made for the core pieces those are little inside to the web mould flange with or without chamfer.
13. The template designing process as claimed in claim 1, wherein the templates are made for the core pieces those are aligned to the web mould flange.
14. The template designing process as claimed in claim 1, wherein the edges of the templates are protected by applying a protecting material at the edges thereof.
15. A template designing method comprising steps of:

a) Setting a plurality of readymade core pieces in a web mould by a trial and error method followed by checking fitment thereof and subsequent removal of a well-lit readymade core piece;
b) Making the straight laminates having sizes relatively larger than the well-fit readymade core piece in step a);
c) Joining and aligning the laminates obtained in step b) to obtain a template having a core piece positioned therebetween; and

d) Holding the well-fit readymade core piece positioned within the template on a clamping apparatus followed by trimming/ sanding the template to obtain a final template having a shape of well-fit readymade core piece.
16. The template designing method as claimed in claim 15, wherein the laminates totally enclose the core piece.
17. The template designing method as claimed in claim 15, wherein the laminates align with the well-fit readymade core piece after trimming the template.