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Judgment
S. Chandrasekaran, Technical Member
This is an original application for revocation filed under Section 64 read with Section 117 D of the Patent Act 1970 ( herein after referred to as the
Act) for revoking the patent No. 198256 dated 24-06-2002 granted to Mr. ALOYS WOBBEN, the Respondent a German citizen.
The impugned Patent was filed on 24-06-2002 claiming the priority date 24-12-1999 and the Patent was granted on 19.5.2006 by the Patent Office
after due examination of the Patent application having the title ""Rotor Blade for a wind power installation"". The applicant is a Company registered
under the Companies Act 1956, a subsidiary of ENERCON GmbH. Germany applied for the revocation of the Patent on the following grounds.
a) The subject matter of the Patentstands anticipated (Section 64 (1) (e));
b) The subject matter of the Patent is obvious and does not involve any inventive step (Section 64 (1) (f));
c) The claims do not clearly define the scope of the invention. (Section 64 (1) (i)).
The applicant stated that they are one of the foremost leaders in the wind energy sectors in India and they manufacture and install wind turbines all
over India and thus they are an interested person within the meaning of the Section 64 of the Act.
The Respondent challenged the competency of the signatory to the application for revocation and the same was heard by this Appellate Board and
passed an order disposing the matter to be decided along with the main matter. Aggrieved by this order, the Respondent appealed in the Madras High
Court, which was heard and disposed off by the Hon'ble High Court directing this Appellate Board to consider and dispose of this preliminary issue
along with the main matter. The Miscellaneous petition was again heard as per the directions of the High Court.
On completion of the pleadings, the matter was listed for final hearing on 15-9-2010 before this Bench. Mr. R. Parthasarathy advocate appeared
for the applicant and the Respondent was represented by Mr. Preston Richard, advocate.
The Respondent filed a M.P. No. 62/2010 on 2-3-2010 questioning the locus standi of the applicant to maintain the present revocation application.
Therefore this has to be considered first and disposed of. Before considering this question of locus of the signatory, let us look into the facts and
background of the case as to its origin briefly.
a. The applicant is a joint venture company. The applicant is involved in the manufacturing of wind turbine generators and setting up of wind farms on
a turnkey basis. There are two shareholder groups of the applicant company, viz., Enercon GmbH, a company incorporated under German law owns
56% of the shareholding of the applicant company as a first shareholder. The members of the Mehra family own the remaining 44% of the
shareholding of the applicant company as a remaining shareholder.
b. There are 4 members on the board of the applicant,
• 2 representatives of Enercon GmbH
• 2 representatives of the Mehra family
• The Chairman of the board is Dr. Aloys Wobben and the Managing Director of the applicant company is Mr. Yogesh Mehra.
• The actual day to day management of the affairs of the applicant company is to be carried out by the Managing Director of the company in India.
c. In 2007, Enercon GmbH filed a petition under the Companies Act, 1956 in the Company Law Board, Principal Bench, New Delhi alleging
oppression and mismanagement of the affairs of the applicant company by the Mehra group members. On 29.10.2007 the Company Law Board
passed an interim order which directed ....""Status quo with regard to all the issues pending in the proceeding should be maintained and no action in
relation to the same shall be taken"" (emphasis supplied). CLB further directed that ....""No changes shall be brought about in the managerial set up and
their responsibilities."" On 19.5.2008 the CLB passed a further order stating that no further board meetings of the applicant company should be
convened without the leave of the Company Law Board thus freezing all the meetings except the day to day activities of the applicant company.
d. The said revocation applications have been filed in January 2009. They were filed in the name of the applicant company and were signed by Mr.
Yogesh Mehra, the Managing Director of the applicant company. The counter statements were filed along with the miscellaneous applications were
also filed questioning the locus standi of Mr. Yogesh Mehra to sign the said revocation applications for and on behalf of the applicant company. Mr.
Yogesh Mehra has signed the revocation applications on the strength of a Board resolution dated 26.4. 2007 which is quite evidently prior to the orders
passed by the CLB dated 29-10-2007.
e. The main arguments of the Respondent are as follows:
• The Board resolution dated 26.4. 2007, by which Mr. Yogesh Mehra is authorized to file proceedings on behalf of the applicant company is bad in
law since it falls foul of the orders dated 29.10.2007 and 19.5.2008 passed by the CLB;
• The Board resolution only authorizes Mr. Yogesh Mehra to manage day to day activities of the applicant company and under the general powers,
to defend the Company and file suits on behalf of the company on matters that may arise out of contractual laws, corporate laws, taxation laws or
any other statutory acts"" but not to initiate these revocation proceedings;
• Mr. Yogesh Mehra having filed a suit in a derivative capacity in the Bombay High Court could not now file this proceeding on behalf of the
applicant company;
• That the validity of the Board resolution has been challenged before the Company Law Board.
• This Appellate Board having been formed substituting for the High Court as regards finalizing the applications for revocation of patents, this
Appellate Board like the High Court has the powers to decide on all the matters of law and those connected matters of legal disputes under CPC;
f. The aforesaid contentions have been refuted by the applicant. The applicant's counsel referred to the Supreme Court of India case in ""Patel
Roadways Ltd. v. Birla Yamaha Ltd. MANU/SC/0202/2000 : (2000) 4 SCC 91"" to show how the Hon'ble Supreme Court of India has decided about
a suit"".
g. On perusing the entire details available in the records, it is seen that Mr. Mehra was authorized by the Board resolution dated 26-4-2007 to sign the
pleadings i.e. the revocation applications. The present revocation applications have been signed by Mr. Mehra by virtue of the said Board resolution
dated 26.4.2007 which empowers Mr. Mehra to do so as is clear from the contents of the resolution produced before us. This Appellate Board cannot
decide upon the validity, legality and propriety of Board resolution dated 26.4.2007 and this Appellate Board, in the absence of any judgment or order
of a competent Court of Law declaring the resolution to be null and void or staying the resolution, has to proceed on the footing and directions given
therein and assume that the said resolution dated 26.4.2007 is perfectly valid and legal. Counsel for the Respondent during the course of arguments
sought to urge grounds in support of the proposition that the resolution dated 26.4.2007 was not proper and legal. However as stated hereinbefore the
legality and/or validity of the Board resolution dated 26.4.2007 cannot be questioned in the present proceedings which are instituted under the
provisions of Section 64 of the Act. The jurisdiction to test the validity and legality of the Board resolution does not rest with this Appellate Board. If
that be so, then the obvious conclusion is that Mr. Mehra by virtue of the resolution dated 26.4.2007 is fully empowered to sign the suits / pleadings
including all these revocation applications. As such there is no substance in the contention of the Respondent that Mr. Mehra has no authority to sign
the pleadings. Further the contention of the Respondent is wrong that the applicant company cannot maintain the present revocation applications. M.P.
No. 62/10 is therefore dismissed.
h. It was further contended by the counsel for the Respondent that the present proceeding is not a suit and as such the resolution dated 26.4.2007
cannot be taken to have empowered Mr. Mehra to sign the same. This argument too is without any substance. It cannot be said that the present
proceeding is not a suit especially in the light of the arguments of the counsel of the Respondent made already, that this Appellate Board is a Court for
all practical purposes, having regard to the nature of the powers and jurisdiction vested in it by statute, which appears that the Respondent is
contradicting his own arguments made already before us. Reliance can be placed in this regard on the law laid down by the Supreme Court of India in
Patel Roadways Ltd. v. Birla Yamaha Ltd. MANU/SC/0202/2000 : (2000) 4 SCC 91. The Hon'ble Supreme Court at paragraph 48 and 49 observed
as follows:
i. ""Suit, Action - 'Suit' is a term of wider signification than action; it may include proceedings on a petition.
From the above it is clear that the terms ""suit"" is a generic term taking within its sweep all proceedings initiated by a part for realization of a right
vested in him under law. The meaning of the term ""suit"" also depends on the context of its user which in turn, amongst other things, depends on the
Act or the rule in which it is used. No doubt the proceeding before a National Commission is ordinarily a summary proceeding and in an appropriate
case where the Commission feels that the issues raised by the parties are too contentions to be decided in a summary proceeding it may refer the
parties to a civil court.... A proceeding before the National Commission, in our considered view, comes within the term ""suit.
j. Therefore, as can be seen from the Supreme Court ruling, the term ""suit"" is not to be strictly construed but construed in the manner in which it is
used. The term ""suit"" has been used in the Board resolution in the context of 'initiation of proceedings' and has to be liberally construed. That apart, the
above mentioned Supreme Court decision, and particularly the admission of the counsel for the Respondent that this Appellate Board is a Court,
clearly establishes that the proceedings before this Appellate Board would also be in the nature of a suit and as such it is clear that Mr. Mehra is
competent to sign the present revocation applications.
k. As regards the derivative action, the circumstances in which the same were filed have no bearing on the present proceedings. The mere filing of a
derivative action cannot and does not act as estoppel of Mr. Yogesh Mehra from filing these revocation applications. The argument of the counsel for
the Respondent in this regard is therefore completely irrelevant and not germane to the issue as to whether Mr. Mehra has the authority to sign the
present proceedings.
l. It was next contended that Enercon GmbH has filed an application before the Company Law Board, New Delhi praying for a stay of the operation
of the Board resolution dated 26.4.2007. The said application was filed on 5.10. 2010. The said application came up for admission on 19.10. 2010
wherein a stay of the operation of the resolution was sought. The Company Law Board has however not granted any interim order. Therefore, as on
date, the Board resolution is valid and subsisting. It has not been set aside or stayed by any court / judicial body. Under these circumstances, it cannot
be said that Mr. Mehra has no locus or authority to sign the revocation applications on the strength of the resolution dated 26.4.2007. As such it cannot
also be held that the applicant company is not a person within the meaning of Sections 2(1)(s) or 64 of the Act.
m. Lastly, reliance by the Respondent on the interim orders passed by the CLB dated 29.10.2007 and 19.5.2008 is completely misconceived and
misconstrued for the sole reason that these orders have been passed after the resolution dated 26.4.2007 and cannot in any manner have any
relevance on the issue as to whether Mr. Mehra has the authority to sign the revocation applications in the present case, particularly when the Board
resolution has not been made null and void.
Basics and objects of the invention to understand the background and nomenclature in respect of ""Rotor blade for a wind power installation"" are:
A. Afflux angle, is the angle between the rotor blade profile chord and the afflux direction of the air.
B. Afflux angle depends on the rotor blade speed-that is to say the speed of rotation of the rotor - and the wind direction
C. The Chord of the blade is the width (the distance between the leading edge and the trailing edge) and it gets less (the blade gets narrower) as the
diameter gets larger.
D. Chord Line: The straight line joining the leading and trailing edges.
E. The 'front' of the blade is the surface that faces towards the wind being flat and angled a bit. Therefore the side of the rotor blade which faces the
direction of the wind is called the 'pressure side'.
F. The 'back' of the blade is facing away from the wind and that is the other side of the rotor blade, which is rounded in shape. This side is called as
the 'suction side' or the 'lower pressure side'.
G. High speed index also called a tip speed ratio ? which is defined as ? = v. tip / v. wind.
Arguments by applicants
I. Relevant Facts:
a. The main application and the miscellaneous petitions were listed for hearing on 09.08.2010. On that day, time was granted till 06.09.2010 for parties
to complete the pleadings i.e. particularly for Respondent to file expert affidavits, if any, in response to the rejoinder and affidavit of the applicant. The
matter was listed for hearing on 13.09.2010 and later adjourned to 14.09.2010 by the IPAB. However, on 14th September, 2010 the
Respondent/Patentee filed their expert affidavits. The Hon'ble Board considered the Respondent's expert affidavit for arguments, in the interests of
justice, despite it being filed in the last minute.
b. It was also pointed out that the Expert Affidavit was signed on 10.09.2010 and notarized on that date but submitted to registry only on 14.09.2010.
This clearly shows the intention of the Respondent to hold back his evidence and see what happens till the last minute and deny reasonable opportunity
to the applicant. Such conduct, especially when they knew of the order dated 8.9.2010 of the Hon'ble High Court of Chennai directing the IPAB to
dispose of the matters within a period of 3 months, disentitles the Respondent to the exercise of discretion by the IPAB.
c. The counsel for the applicant started his argument inviting our attention to the definition of the ""patent"" as under Section 2(1)(m), ""invention"" as
under Section 2(1)(j), ""inventive step"" as under Section 2(1)(ja), respectively of the Act. The counsel submitted that how the applicant satisfies the
condition of ""person interested"" and what is the definition of ""person interested"" as given in Section 2(1)(t) of the Act. Then the counsel submitted that
inventive step being one of the ground, its definition and analysis with respect to the claims, particularly the scope of definition of the claims, from
which the feature regarding the technical advance or economic significance or both and that makes the invention not obvious to a person skilled in the
Article
Then the counsel submitted his arguments as follows:
II. Invention and Inventive step:
i. A Patent is granted for a single invention only. Accordingly the claims and the complete specification shall relate to a single inventive concept.
ii. The question as to whether the invention as claimed, is obvious has to be judged from the view point of the person skilled in the Article
iii. Invention can either be a product or process but is new, having an inventive step and has industrial application.
iv. Section 2(1) (l) defines a new invention. It was submitted that an invention is not new if all the elements of the invention, as contained in the claim
or claims, are disclosed in a single prior art document.
v. Since one of the grounds for revocation in the Application is 'lack of inventive step', the definition of inventive step is important.
vi. Inventive step is that feature of the invention which represents a technical advance over the existing knowledge or has an economic significance or
both and which is not obvious to a person skilled in the Article
vii. Thus, inventive step is a two step analysis. At first, we have to identify from the claims (since the claims define the invention for which protection
is sought - Section 10(4)(c)) that feature which is the technical advance or economic significance or both. Only after that feature is identified it is
necessary to examine the question whether that feature is obvious or not to the person skilled in the Article
viii. If the analysis in step 1 results in a finding of no such feature then the alleged invention lacks inventive step.
ix. The attention of this Board was also invited to Section 7 (1) to show that a patent is for a single invention only. Attention was also invited to Section
10(5), according to which the claims and complete specification shall relate to a single inventive concept. It was, therefore, submitted that there will be
only one common inventive step/concept pervading all the claims.
III. Constructional details of the Invention
i. Claim 1 reads as follows:
A rotor blade for a wind power installation, the rotor blade divided longitudinally into a two integrally connected portions, a first one of the portions
being closer to a root of rotor blade and second one of the portions having farther from the root of the rotor blade, the first portion having a first angle
of attack so that a power coefficient of the first portion is maximized at a first high-speed index, the second portion having a second angle of attack,
different from the first angle of attack, so that a power coefficient of the second portion is maximized at a second high-speed index, wherein the
second high-speed index is greater than the first high-speed index.
ii. According to Patent Specification, High speed Index (?) is defined as Vtip/Vwind. (Velocity of the tip of the blade to the velocity of the wind). Vtip
is inversely proportional to the afflux angle. According to the Patent, the power coefficient is proportional to the efficiency of the rotor blade.
iii. In case of gusty winds, the tracking/adjustment of the speed of rotation of used rotor rotation is not possible in respect of corresponding speed
and/or accuracy. As a result, at winds of very high speed, the afflux angle becomes too large because of which the rotor blade goes into stall range
(Specification, Page 14; last Paragraph).
iv. In order to regulate the rotor blade such that it does not go into stall range, the rotor blade is operated at a high-speed index which is somewhat
above the high-speed index which correlates to the maximum power coefficient. In such operation there is a disadvantage if there is a sudden increase
in wind speed, the maximum level of efficiency is increased but flow begins to break because of which sometimes the power yield is not maximum.
Thus, the object of the invention is to reduce the sensitivity of the rotor blade.
v. According to the Patent, this object is achieved by having a rotor blade which is divided in its longitudinal direction into at least two integrally
interconnected portions which are designed for maximum efficiency at different high-speed indices. Further, there is a transition portion between these
two interconnected portions, which is comparatively short in comparison with the length of the portions so that a flow breakdown is stopped at the
transition portion. Further, according to Patent, power coefficient of the portion which is farther away from the rotor blade root is greater than the
high-power index, associated with the maximum power coefficient, of the portion which is respectively closer to the rotor blade root.
vi. Further, according to the Patent, the rotor blade is subdivided into a longer inner portion and a shorter outer portion. There is also a transition
portion between both the portions.
vii. The Patent also states that the larger rotor blade portion has a smaller angle of attack and smaller rotor blade portion has a greater angle of attack.
The applicant's counsel continued his arguments next based on the grounds relied in the revocation application and submitted as follows:
A. Against the construction of claims
Claim 1 claims a high speed index for each rotor blade portion i.e. the rotor blade as claimed in claim 1 has two high speed indexes whereas the
Patentee states in its counter statement (Para 7.8) that there is only one tip speed.
The Respondent argued that as per the definition of high speed index in the Specification, and as per the interpretation of claim 1, at any given point
of time, Vtip will be constant over the entire length of the blade. This is contrary to claim 1 where it is claimed that the blade has two different values
of high speed index, one near the root and the other near the tip.
In this regard applicant relied upon expert affidavit of Mr. K. Manjunath Udupa. The expert has stated that there is a contradiction in the stand of
the Respondent and claim 1 would be wrong if a person relies on the Respondent's admission in his counter-statement. Applicant pointed out the fact
that there is no rebuttal to this expert view by Respondent or by Respondent's expert.
The applicant also relied upon the expert affidavit of Prof. Kunal Ghosh, who also opined that claim 1 would be moot and incorrect if a person relies
on the Respondent's admission in its counter-statement. Hence there is a contradiction in Respondent's stand. It was also pointed out by the applicant
that there is no rebuttal to this affidavit also.
In this regard the Respondent argued that Vtip remains constant over the complete blade and it is Vwind which varies in the whole process and
hence the high speed index (tip ratio) will vary.
In that context applicant pointed out that there is no support for such limitation either in any of the claims or anywhere in the specification and hence
the person skilled in the art would not consider such limitations in claim 1. Hence this construction cannot be taken on record and claim 1 has to be
understood only in a way that rotor blade has two tip speeds.
The applicant pointed out that in claim 1 claims 'at least two integrally connected portions'. It was also pointed out by the applicant that the Patent
states that rotor blade is divided in its longitudinal direction into at least integrally interconnected portions (Revocation Petition, Page 16, line 20). Thus,
it was argued that according to claim 1, the rotor blade has two parts which are connectable to each other.
B. Claims are anticipated
According to Patent Specification, High Speed index (?) is defined as Vtip/Vwind. It is submitted that Vtip is equal to rotational velocity of the blade
in radius per unit time multiplied by the radial length of the blade. Since the radial length of the first portion closer to the root of the blade is smaller
than that of the second portion, the Vtip of the second portion will be greater than that of the first portion. As a natural corollary, for a given wind
speed, the ? for the second portion will be greater than that of the first portion. Hence, there is no novelty in claim 1.
2 The applicant relied upon US Patent US '301 Patent to prove that the claims of the impugned Patent are anticipated. It was pointed out by the
applicant that US '301 Patent relates to an improved blade design and more preferably to an improved windmill which includes a self-governing turbine
blade system and an improved apparatus for coupling the turbine to an electric generator.
3 Further, it was pointed by the applicant that US '301 patent relates to wind turbine with rotor blades having two portions which have been described
as blade systems. These blade systems have been longitudinally situated and have different tip speed ratios (equivalent to high speed index) at which
they reach their maximum efficiencies.
4 It was also pointed that the tip speed ratio of the outer portion at which it reaches maximum efficiency is greater than that of the inner portion (Page
36, column 7, lines 40-48 read with figure 7). Further, the applicant pointed out that the object of US '301 Patent and impugned Patent is same as both
the patent aims to achieve the maximum power efficiency.
5 In response to this, the only argument Respondent submitted was that the US '301 patent discloses two rotor blades and not one rotor blade with two
portions.
6 In this respect, the applicant relied upon its previous arguments and further pointed out that claim 1 claims a rotor blade having two integrally
connected portions and US '301 patent also discloses two integrally connected blade portions and hence claim 1 is anticipated by prior Article
C. Claims of the Patent are obvious
a. The applicant pointed out that the teachings of helicopter would be relevant prior Article In this respect, the applicant relied upon Para 3.23 of its
reply where the applicant had stated that wind turbines and helicopters, though designed for different objectives, share similar aeroelastic problems. A
sizeable rotor dominates behavior of both the systems. Its rotary blades elastically coupled with surrounding air and other system components to
influence overall performance, vibration, loads, and stability. Because of these similarities, the aeroelastic tailoring techniques developed for helicopter
blades can be readily applied to wind turbine blades. It is also submitted that the general optimal aeroelastic tailoring approach however is similar for
both systems. The nature of design variables is also the same for both helicopter and wind turbine blades. There was no rebuttal by the Respondent to
this technical argument and hence this argument stands valid.
b. Arguendo, if US '301 Patent does not anticipate the impugned Patent, in that case for a person skilled in the art the teachings of US '301 Patent
would be the starting point to reach the teachings of the impugned patent.
c. Further, the applicant relied upon '094 Patent at Page 41, lines 77 to 80 to prove that it discloses a blade structure, wherein the blade has multiple
angles of attack, by virtue of warping and is formed in a single construction. It has various intermediate angles, ranging from 1 degree to 40 degrees.
The applicant also pointed out that Figure 2 clearly depicts the said intermediate angles. Further, the applicant pointed out that Page 42, lines 46 to 66
discloses two blades attain the maximum power (maximum efficiency) at different tip speed ratios. From the combined teachings it would be obvious
for those skilled in the art to combine and be motivated to make a rotor blade with integral construction but with different portions having different high
speed indexes at which the respective portions attain their maximum efficiencies. Therefore, the invention claimed in Claim 1 cannot be said to be
inventive and is obvious.
d. There was no response by the Respondent to this combination. The Respondent only tried to differentiate the teachings of individual prior art, which
is not permissible to overcome the obviousness ground.
D. Arguments relating to Expert Affidavits
a. The applicant also relied upon its expert Mr. Kunal Ghosh's opinion that the Patentee has made contradictory statements in its reply. According to
expert Claim 1 claims two different high speed indexes whereas the Respondent/Patentee states in its reply there is only tip speed (Vtip) for each
rotor blade. If there is only one tip speed for each rotor blade then there can't be two different high speed indexes as claimed by the Respondent in
claim 1. As admitted by the Respondent that there is only one tip speed thus, claim 1 is wrong.
b. The applicant also pointed that this expert has stated that the specification does not disclose the invention and the Patentee has made many
contradictory statements in the specification itself (Para 6 of the opinion). Thus, a person skilled in the art would not be able to practice the invention
as per the teachings of the impugned Patent.
c. Further, the applicant pointed out Paras 10 to 20 of the said opinion to argue that the invention as claimed in claim 1 of the impugned Patent is
anticipated by the teachings of US '301 Patent.
d. Further, the applicant also pointed out the opinion of Mr. Udupa to state that the Respondent has made contradictory submissions in its reply (Para
7). Further, the applicant relied upon Para 9 of the expert to prove the level and knowledge of the person skilled in the art before the priority date.
e. The applicant further submitted that the Respondent's expert has not rebutted either Mr. Ghosh's affidavit of Mr. Udupa's affidavit. Their expert
has merely summarized the prior arts and stated as to how individual prior arts would not make the invention obvious. The expert has not brought any
new point about the teachings of US '301 Patent and the contents were in substance repetition of the Respondent's arguments.
Arguments by Respondent
A. The counsel for the Respondent started his arguments first referring to the M.P No. 62 of 2010, where the Respondent had challenged Mr.
Yogesh Mehra's competency to depose an affidavit and has no locus standi to initiate revocation application on behalf of Enercon (India) Limited and
the request was made to decide the locus standi issue along with other grounds of the revocation application.
B. Basic details
i. As submitted, it is pertinent to draw the attention of the Board to the fact that the novelty and inventiveness of the subject patent have been
internationally recognized. Details of corresponding applications are provided below.
ii. As noted above many corresponding applications have matured into patents in the number of countries such as Canada, Europe Japan, Korea and
the USA. Further as noted above, the patentee was granted a patent in Europe which is also covering UK. It is pertinent to bring notice to the Hon'ble
board that after grant of the European patent, an opposition was filed and later the opposition was withdrawn. However, it is of significance to note
that in Europe, the opposition division can continue the opposition proceeding sue-moto, even after the opponent has withdrawn the opposition. In the
present case, the opposition division considered the patent to be valid and decided to have the patent as it is.
iii. The invention relates to a design of a rotor blade for a wind power installation. The patent as granted defines in detail the object and the
background of the invention. Fig.1 of the complete specification define the afflux and the rotor speed in comparison to the wind velocity (V wind) and
tip velocity (Vtip). It is also well known in the art that the high speed index also called a tip speed ratio A which is defined as ? = Vtip/ Vwind.
iv. The present invention involves certain terms such as tip speed Vtip, high speed index (a.k.a tip speed ratio ?) and wind speed (V wind) which
follows the standard definition used in the Article
v. As seen in above the high speed index (tip speed ratio) is dependent on two factors i.e. wind speed and tip speed. The change in tip speed is
directly proportional to the change of high speed index (tip speed ratio). And, the change in the wind speed is indirectly proportional to the high speed
index (tip speed ratio).
C. The problem encountered
i. When the wind is gusty and squally tracking adjustments of the speed of rotor is not possible with respect to corresponding speed and accuracy.
Therefore when there is a rapid rise in wind speed the afflux angle becomes too great and the flow at the suction side of the rotor blade breaks down
causing no lift. In order not to go into the stall range the speed of rotor is regulate, however this does not solve the problem and the flow begins to
break down. This is clearly shown in Figure 2 of the present invention
 (Editor: The text of the vernacular matter has not been reproduced. Please write to contact@manupatra.com if the vernacular matter is
required.)
ii. Therefore the object of the present invention is to reduce sensitivity of rotor blade to turbulent wind flow. The flow break down begins the region
close to the rotor blade and spreads outwardly. Therefore it is the intent of the invention to design the blade which would solve the problem of stalling
as well as regulate the flow break down in the blade.
D. Summary of the invention
The present invention seeks to overcome the problem by designing a rotor blade which is divided in its longitudinal direction into atleast two integrally
connected portions designed to perform at the maximum power coefficient at different high speed indexes. Claim 1 of the subject patent 198256 reads
as under:
A rotor blade for a wind power installation, the rotor blade divided longitudinally into at least two integrally connected portions, a first one of the
portions being closer to a root of the rotor blade and a second one of the portions being farther from the root of the rotor blade, the first portion having
a first angle of attack so that a power coefficient of the first portion is maximized at a first high-speed index, the second portion having a second angle
of attack, different from the first angle of attack, so that a power coefficient of the second portion is maximized at a second high-speed index, wherein
the second high-speed index is greater than the first high-speed index.
2 This claim clearly brings out the present invention where a rotor blade is designed having two integrally connected portions. Of the two portions one
being closer to the hub rotor blade and the other being further. This is clearly illustrated in Figure 3 by way of example where two portions have been
designed for different high speed indexes. The separating line shown in Figure 3 for illustration purpose only as clearly pointed out in the specification.
 (Editor: The text of the vernacular matter has not been reproduced. Please write to contact@manupatra.com if the vernacular matter is
required.)
Figure 5 shows the three dimensional view of the rotor blade designed in accordance with the invention.
(Editor: The text of the vernacular matter has not been reproduced. Please write to contact@manupatra.com if the vernacular matter is
required.)
The rotor blade is designed having two portions with different angle of attack such that the power coefficient is high for a portion of the rotor blade
at a particular high speed index. This variations of power coefficient in dependence of high speed index is shown in Figure 4 of the sheet No. 2 of the
drawings accompanying the patent specification.
E. Ground raised by the applicant
The applicant has challenged the instant patent under 64 on three grounds namely 64(1)( e)-Anticipation, 64(l)(f) -Obviousness and 64(l )(i) -Claims
not Clear. Provided below is the chart of claims attacked on various grounds based on cited documents:
i. Anticipation
a. The applicant had objected to claim 1 as lacking in novelty due to natural corollary based on different tip speeds. Subsequently the Respondent had
clearly pointed out in the counter statement that the rotor blade has single tip speed as it has a single tip. Therefore the natural corollary of different
high speed indexes does not stand as the rotor blade of the present invention has only one tip and therefore a single tip speed.
b. The two Expert evidences put forth by the applicant contested this submission saying that there cannot be different high speed indexes without
different tip speeds.
c. In reply the Respondent maintains that since this rotor blade has a single tip therefore has a single tip speed. It is only possible to have different tip
speeds for different rotor blades and not for a single rotor blade. However as noted above the high speed index (tip speed ratio) does not only depend
on the tip speed but also the wind speed. This is clearly shown in page 3 line 15 of the granted patent where it reads ""changing winds involves a
change in the high speed index with constant speed of the rotation of the rotor"". Therefore it is possible to have designed a single rotor blade having
two portions which works at its maximum power coefficient for different high speed indexes (tip speed ratio), since it also depends on the wind speed.
d. Therefore the main contention of the applicant that it is impossible to have a rotor blade designed for two high speed indexes stands moot. Further
the expert evidence which has raised issues on this ground has clearly ignored the change in wind speed and thus clearly given false observation and
therefore should not be considered.
e. The applicant has objected to claim 1 as lacking in novelty with respect to US 4150301 (hereinafter US '301). As already noted that this document
was cited by the Indian Examiner (copy of the FER was placed during hearing). Further it was also cited by the Examiner in the corresponding US
and EP applications subsequent to which this patent was granted in these countries including India. However without prejudice to the above we submit
our arguments against the cited document US '301
f. The applicant describes the patent US '301 to have two portions (part 14 and 22 in Fig 1). However Respondent submitted that the applicant has
misrepresented the facts of the cited document. The US '301 patent is not directed to rotor blades having two portions, but two different rotor blades,
as item 14 is directed to a low speed blade system comprised of three structural low speed blades 16 and nine non-structural low speed blades 18,
whereas numeral 22 is directed to three outer high speed blades 22 (column 4, lines 13 to 22). Further the inventor throughout the document has
addressed these blades to be independent blades and not as two portions to the single blade. Accordingly, the allegation of the applicant in this respect
that US '301 would show a single blade with different portions is incorrect.
Figure 1 clearly shows two different rotor blades (22 and 16, combined by a rim to form a system.
 (Editor: The text of the vernacular matter has not been reproduced. Please write to contact@manupatra.com if the vernacular matter is
required.)
h. Respondent submitted that this interpretation is entirely wrong as the inventor of Patent US '301 did not conceive this at all at the time of invention.
This is clear from the cited document para 4 line 17 onwards where the inventor did not mandate both the blades to be on the same plane. Infact the
inventor had designed such that the blades 16 are approximately coincident with and parallel to blades 22. Therefore it is clear that if one blade is
parallel to other they cannot be connected. The purpose of the structural blades 16 was for transmission of energy to the hub and not for any other
purpose. This cannot also be clearly seen in Figure 4 of sheet 2 of the drawing accompanying the patent specification, where the blade 22 is
connected to the rim at the corner whereas the low speed blades 16 is connected from the hub to the rim and clearly looks to be disconnected from
the outer blade.
j. Subsequently as seen in Figure 6 of sheet 4 of the drawing accompanying the patent specification, the cross section of profile of the rotor blade
system where the inner blades and the outer blades have been shown. This clearly shows that the inner blade 16 at the point where it is connected to
the rim (shown here as 156) is clearly disconnected to the inner portion of the outer blade connected to the rim (shown here at 154). This clear
misalignment between the two blades is compensated by the rim and thus the blades can never be connected with each other. Therefore the whole
contention of the cited document having a blade with two portions is moot.
k. Secondly in the cited document the low speed blade system 14 is designed to have a maximum efficiency at relatively low fluid velocities (e.g., wind
velocities) while the high-speed blades 22 are designed to have a maximum efficiency at relatively high fluid velocities (column 4, lines 30-35). In
addition, US '301 teaches that the low speed blade system 14 actually achieves a negative efficiency (i.e., removes energy from the turbine blade
system 10) when the turbine blade system 10 is exposed to relatively high fluid velocities (column 4, lines 35-48). The purpose of the turbine blade
system 10 of US '301 is to make the system self-governing at high fluid velocities (column 4, line 40) by dissipating energy.
i. Contrary to the teachings in US '301 the patentee's claim 1 is directed to a wind power installation in which a first portion (i. e., inner portion) of the
rotor blade is designed to operate in a range of optimal power when the wind velocity is relatively high. Figure 4 of sheet 2 of the drawing
accompanying the patent specification of the patent is instructional in diagramming the relationship between the coefficient of power (cp) and the high-
speed index (CA.). Figure 4 of sheet 2 of the drawing accompanying the patent specification illustrates that as the wind velocity increases and the
high-speed index decreases, the first portion of the rotor blade is urged to operate in a range of optimal power. Accordingly, US '301 does not
anticipate patentee's claim 1 because the reference discloses the contrary.
m. It is well accepted fact that if the independent claim is novel, the subject-matter of the dependent claims are also considered novel, however
without prejudice to the above statement, the Respondent refutes the challenge to the dependent claim 2 and 5 in view of the US '301. Having said
that it is the duty of the applicant to challenge each and every claim if considered anticipatory and therefore cannot rely that the novelty of the
dependent claims would be destroyed if the independent claim 1 is found not novel. However our arguments provided with the counter statement may
be taken on record for purpose of defending our claims.
n. The Respondent had placed before the board certain extracts from the Fourth Edition of Patent Law by P. Narayanan. Reliance was placed on
page 381 where the author had quoted judgments with regard to anticipation. The same is provided below for easy reference:
To anticipate the patentee's claim the prior publication must contain clear and unmistakable directions to do what the patentee claims to have invented.
A sign post, however clear, upon the read to the patentee's invention will not suffice. The prior inventor must be clearly shown to have planted his flag
at he precise destination before the patentee.
o. It is clear that the cited document in no way reads or shows each and every features of the present invention. And therefore would fail miserably
as a document for anticipation.
p. Subsequently in the rejoinder the applicant had relied upon the enabling disclosure for anticipation. In reply the Respondenthas placed reliance on
page 381 and 382 of the extracts where it was noted as below:
The information given in the prior document must be sufficient to enable the instructed reader at once to perceive and understand and be able
practically to apply the discovery without the necessity of making further experiments. ""Experiment"" in this context means experiments with a view to
discovering something not disclosed and does not mean ordinary methods of trial and error.
It has been held under Section 2 of the U.K. Act 1977 that for a disclosure to be effective against novelty it had to be an enabling disclosure, i.e., it
must disclose a method of working the invention. An invention was not made available to the public merely by a published statement of its existence,
unless the method of working was so self-evident as to require no explanation.
Therefore it is also clear from the above that the cited document in no way provides a person skilled in the art to be able to practically carry out
further experiments.
ii. Obviousness
a. Applicant alleges claim 1 is obvious in light of US 1 ,802,094 (hereinafter ""US '094"") read with US '301. The US '094 patent is directed to high
speed turbines or a high speed wind turbine. The applicant refers to page 1, lines 77 to 80 of US '094, as disclosing the blade of said wind turbine is
warped, and the angle of the blade increasing from approximately 1 degree to 40 degrees.
b. The applicant uses this as a starting point to combine US '094 and US '301. The US '094 patent describes two rotor blades to be used at a wind
energy plant. The first is intended for use in a wind turbine with only one rotor blade, whereas the second with two blades. Therefore the rotor blades
are composed of different blade profiles because of their different nominal rotation speeds. The twisted orientation of the profiles starting with a large
angle of incidence near the rotor hub and showing a continuous decrease of the angle of incidence towards the rotor tip is a general state-of-the-art
feature of any propeller and rotor design. Due to the variation of the linear speed in radial direction, this rotor twist is necessary to overcome the
stalling effects in the outer radial portion and the too low or even negative without twist. This would result in a very inefficient aerodynamic force
distribution across the rotor plane.
c. The rotor blade itself cannot be rotated around its longitudinal ,axis (fixed-pitch) and therefore cannot be used with the present design.
d. Further the US '094 further discloses on page 1, columns 84 and 85 that the blade has a no-load tip-speed-ratio of 11. Accordingly, the complete
blade has one single tip speed ratio. Further considering the fact that the US '094 is directed to high speed turbines or high speed wind turbines, it is
clear that the rotor blade is optimized with respect to this high speed and providing an optimized air foil. In fact, US '094 clearly describes on page 1,
lines 80 to 84 that a good air foil is assumed. Accordingly, both documents US '301 are directed to completely different objects.
e. In the present invention, the object is to make a rotor blade less sensitive to turbulent wind flows. None of the documents US '301 and US '094
provide any solution to this problem. In addition, none of these documents discloses an improvement of a rotor blade design in this respect.
Accordingly, the person skilled in the art will neither find any indications of the problem nor any indications for a solution in the cited documents US
'301 and US '094. Therefore in view of the above, the subject-matter of claim 1 is inventive in view of US '301 and US '094.
f. The applicant also cited two documents US 4'037'988 (US '988) and US 5,263,846 (US'846), however had not pressed during the hearing. The
Respondent however provides his arguments on this as relied upon in the counter. US 4'037'988 (US '988) is cited with respect only to dependent
claim 6. The US '988 is directed to a helicopter. The person skilled in the art will not even consider a disclosure regarding helicopters for many
reasons. A helicopter transforms energy into an air flow in order to lift the helicopter, whereas a wind power installation transforms energy from an air
flow (the wind) into mechanical or electrical energy. In other words, the working principle is exactly the opposite. Additionally, the rotor of helicopters
is not subjected to different air flows, as a helicopter is producing its air flow itself. These are just two examples for principle differences of a wind
power installation and a helicopter. Even further, any features provided by a helicopter have completely different purposes to features of a wind
power installation and thus even if a person skilled in the art would combine documents, he would not find any features for similar purposes.
g. The US 5,263,846 (US'846), which has only been cited with respect to dependent claim 7, is also directed to a ""rotary wing aircraft"", which is in fact
a helicopter. Accordingly, this document is also no relevant state of the Article Therefore both these documents cannot be relied upon for obviousness.
iii. Expert evidence
a. The opponent had given two expert evidences who have used the same terminology as that of the applicant contrary to the terminology used in the
cited document.
b. The Experts addressed the blades as portion of blade and have both conveniently ignored and have both used the same marked Figures and
arguments, therefore mimicking the applicant's arguments. Further the claim has been conveniently broken down ignoring a single rotor blade
therefore trying to interpret it as the blade of cited document. This is done by both the experts therefore raising serious doubts on the independent view
of the expert.
c. None of the documents cited by the applicant either alone or in combination renders any of the granted claims of the patent 198256 as obvious and
lacks novelty and the revocation application be dismissed.
Rejoinder to the submissions made by the Respondent
a) The Respondent argued that equivalent patents have been granted by USPTO and EPO and hence the presumption of validity is there. The
applicant pointed out that this statement is half truth and is done to mislead the Board. Although, USPTO/EPO has granted the patent, it should be
noted that the granted claims in patents US 6,899,523 and EP 1,244,872 which are US and EP family members of the subject patent '256, have been
amended substantially and the granted claims are totally different as compared to those granted by the Indian Patent Office. Moreover, the validity of
a patent cannot be guaranteed simply because corresponding patent applications have been granted by patent offices in other jurisdictions.
b) Further, the Respondent argued that there is a single rotor blade having only one tip speed and hence the interpretation of the applicant is incorrect.
Further, the Respondent argued that in claim 1 the main inventive feature is 'angle of attack' and not 'tip speed ratio'. In this regard, the Respondent
relied upon internal page 3 of the patent specification to state that changing winds involve a change in the high-speed index. In this regard the applicant
argued that changing winds is not an element in claim 1 and hence this interpretation cannot be taken on record. The applicant pointed out that during
arguments the Respondent cannot bring in limitations in claim 1 which are not present in as-filed claims. Hence this argument of the Respondent
cannot be taken on record.
c) The Respondent argued that US '301 Patent discloses two integrally connected blades and not one blade system and hence US '301 Patent cannot
anticipate the impugned Patent. In this regard the applicant argued that Claim 1 claims two rotor blade portions which joins integrally to form two clear
separate parts. Nowhere in claim 1, has the Respondent claimed one complete blade system and hence this argument of the Respondent is not
tenable.
d) Further, the Respondent argued that as per the impugned patent the inner region of the blade has lower speed whereas the outer region of the blade
has higher speed. In this regard, the applicant pointed out that US '301 Patent also discloses the same. The applicant relied upon Page 36, column 7
lines 40 to 48 to show that the inner blade portion of US '301 had lower speed whereas the outer blade portion of US '301 had high speed. Thus, the
blade system had the features (speed of the blade portion; maximum efficiency) same as the features of the blade as claims by impugned patent and
hence US '301 Patent discloses the subject matter of the claimed invention.
e) Further, the Respondent argued that the object of US '301 Patent is different and hence that prior art cannot be a relevant prior Article In this
regard, the applicant argued that the object of the prior art does not matter. A person skilled in the art would look into the teachings of the prior art and
would not restrict itself to the object of the prior Article
f) The Respondent pointed out that Positive efficiency (maximize the power co-efficient) is being achieved by these rotor blades which is not achieved
by the blades disclosed in the prior art US '301 Patent. The Respondent argued that the function of the blades as claimed in claim 1 is to maximize the
power and this function is not disclosed anywhere in US '301 Patent. In this regard the applicant pointed out that arguendo if the blades are not
integral, that is, not made in one piece, then also it is designed to perform substantially the same function in substantially the same way to achieve the
same result. In the said patent, the function is to provide high speed index by way of angle of attack, and the result is to maximize the power
coefficient. In this respect the applicant relied upon Para 3.12 of its reply to show that both the blade system performs the same function i.e. maximize
the power co-efficient. Hence the function of the blade system as claimed in '256 Patent is very well disclosed by US '301 Patent.
We have heard the arguments of both the counsel and have gone through the pleadings and the documents filed in support thereof.
Person interested
In this case, the Respondent has raised a question of locus standi for the person who has filed the application for revocation for and on behalf of the
applicant s that he is not authorized and is not ""the person interested"" to file a revocation application. The Respondent has taken the ground that in
terms of the articles of association of the company, Mr. Yogesh Mehra, the Managing Director lacks the competence to file a revocation application
for and on behalf of the applicant s for revoking the patent granted to the Respondent, as the reliance placed on the articles of association is wrong
and the power is not conferred on him to execute any such legal action, and more so when the matter is still pending before the company law board.
The applicant had stated that Mr. Yogesh Mehra, being the Managing Director has been authorized by the Board resolution dated 26th April 2007 to
defend and initiate suits and proceedings on behalf the applicant and that in terms of the articles of association of the company, Mr. Yogesh Mehra,
being the Managing Director has the requisite locus standi to file and institute the revocation proceedings. Appellate Board has the power only to
check as to whether the applicant filing the revocation, namely the applicant company, herein M/s. Enercon (India) limited is a ""person interested"" or
not, according to the Act under which this proceeding has been initiated.
Now we wish to point out that this issue of locus standi of Mr. Mehra has already been discussed and decided earlier in Para 6(g) ante. The
Company Law Board having not granted any interim order after 29.10.2007 and 19.5.2008, as on date, the Board resolution is valid and subsisting. It
has not been set aside or stayed by any court / judicial body. Under these circumstances, it cannot be said that Mr. Mehra has no locus or authority to
sign the revocation applications on the strength of the resolution dated 26.4.2007. As such it cannot also be held that the applicant company is not a
person within the meaning of Sections 2(1)(s) or 64 of the Act.
Now we have to see whether the applicant is a person interested or not to file a revocation application. According to Section 2(1)(t) of the Act,
person interested"" is defined as below:
Person interested"" includes a person engaged in, or in promoting, research in the same field as that to which the invention relates;
The word or expression ""person interested"" appears under Sections 25 as well as 64 of the Act, dealing with opposition proceedings to the grant of
patent before the Controller and revocation proceedings before this Appellate Board. In fact the actions taking place in opposition proceeding is almost
analogous and similar to the revocation proceedings before this Appellate Board, excepting for the creation or constitution of an opposition Board
under Section 25(3) (b) of the Act, to examine and submit the recommendation to the Controller who is to hear the opposition parties. As per Patent
Law by P. Narayanan, it could be clearly seen or stated that there are three grounds upon which the opponent can establish his locus Standi to oppose
the grant of patent or to seek the revocation of the patent, which are mainly,
1) possession of patents in the same field as the invention relates;
2) manufacturing interest relating to a similar product being manufactured by the patentee; and
3) trading interest.
As per the Act, all the claims in a complete specification will have one inventive step or making them to be having group of inventive features to
have a single inventive concept. Since that inventive step in the principal claim 1 has been shown to be obvious, all the subsidiary claims dependent on
the principal claim 1, which tend to add only minor variations of features will not impart any inventive step to the dependent claims.
AIR 1983 DELHI 496 Ajay Industrial Corporation v. Shiro Kanao of Ibaraki city, para B in page 496, it was held that, ""person interested"" must be
a person who has a direct, present and tangible commercial interest which was injured or affected by the continuance of the patent on the register.
The applicant's counsel stated at the very beginning, that they are the one of the foremost leaders in the wind energy sectors in India and they
manufacture and install wind turbines all over India and thus they are an interest person within the meaning of the Section 2(t) as well as the Section
64 of the Act. In view of this judgment, we have to check and find out whether this applicant is a person interested as per the requirement of the Act
under which these proceedings are taking place.
It was further held in the above cited case that ""the person interested within the meaning of Section 64 must be a person who has a direct, present
and tangible commercial interest or public interest which is injured or affected by the continuance of the patent on the register.
In Globe Industries Corporation's Patent (1977) R.P.C 563 in the Supreme Court of Judicature - Court of Appeal, Lord Justice Scarman observed
that, ""where the statute uses the words 'any person interested', the interest has to be genuine; the possibility of prejudice has to be genuine and in
addition, and quite independently, the Court must be satisfied that the opposition or the application for revocation, as the case may be, is not a frivolous,
vexatious or blackmailing operation.
And in the same case law, Globe Industries Corporation's Patent (1977) R.P.C 563 in the Supreme Court of Judicature - Court of Appeal, Lord
Justice Goff observed that, ""what an opponent on an application for revocation has got to establish is that there is genuine interest which may be
prejudiced; Of course, the prospect of prejudice must be real, not speculative or fanciful and it must be a prejudice to present a commercial interest.
In Mediline A.G's Patent (1973) R.P.C 91 before the patents Appeal Tribunal, Mr. Justice Graham has held that, ""there must be a real, definite
and substantial interest to prove the commercial interest and that it must be a genuine interest. There must be the existence, or the likelihood of real
prejudice.
Therefore applying the same analogy here, we find that, as regards first ground, there is no evidence before us to show that the applicants are in
possession of any patents in the same field. As regards the second ground i.e., the manufacturing interest, the applicants are one of the foremost
leaders in the wind energy sectors in India and they manufacture and install wind turbines all over India and this establishes the manufacturing interest.
As regards the trading interest, looking at the ruling of the Solicitor General, Sir Thomas Inskip in Clavel's application 45 R.P.C 222 and a previous
ruling by Sir Stanley Buckmaster in New Thing's application 31 R.P.C 40 that ""a trading interest to be effective, must be a real, definite and substantial
interest and must not arise from something that the opponent proposes to do"".
It is very clear that the applicants have been manufacturing and installing the wind turbines shows the trading interest of the product, too, as ""a
person interested"" in opposing the grant or revocation of the patent. Therefore what an applicant for revocation of patent, has to establish is that there
is a real and genuine interest together with a commercial interest, which may be prejudiced when such a patent is granted. The applicants have shown
that they have been manufacturing and installing wind turbines all over India and this shows that they have a real and genuine interest together with a
commercial interest in the product. In view of the above said findings, we find that undoubtedly locus Standi is established by the applicants and they
are ""the person interested"" in this case sufficiently meeting the requirement of Section 2(1)(t) of the Act.
Common general knowledge
Now we shall see as to whether a common knowledge on the date of the patent would amount to anticipation by way of public knowledge
destroying the novelty or affecting the inventive step. First we should see what is a common general knowledge?
Criteria for ""Common General Knowledge
It is important to have a clear understanding of the meaning of the common general knowledge. It is the background technical knowledge available to
all in a particular trade while doing or carrying out a product development activity.
The common general knowledge as described by Laddie J in Raychem Corp's Patents (1998) RPC 31 , ""The common general knowledge is the
technical background of the notional man in the art against which the prior art must be considered .... It includes all that material in the field he is
working in which he knows exists, which he would refer to as a matter of course if he cannot remember it and which he understands is generally
regarded as sufficiently reliable to use as a foundation for further work or to help understand the pleaded prior Article This does not mean that
everything on the shelf which is capable of being referred to without difficulty is common general knowledge nor does it mean that every word in a
common text book is either. In the case of standard textbooks, it is likely that all or most of the main text will be common general knowledge.
The law as to what constitutes common general knowledge is also set out in the decisions of the Court of Appeal in General Tire and Rubber Co v.
Firestone Tyre and Rubber Co Ltd (1972) RPC 457 and Beloit Technologies Inc v. Valmet Paper Machinery Inc (1997) RPC 489 ;
In General Tire v. Firestone (1972) RPC 457 it is held, 'on the other hand, common general knowledge is a different concept (sc. from public
knowledge) derived from a commonsense approach to the practical question of what would in fact be known to an appropriately skilled addressee -the
sort of man, good at his job, that could be found in real life.'
In Beloit v. Valmet (1997) RPC 489 (CA)). Aldous J held; ""At the same time, the skilled man should not be taken to represent some sort of lowest
common denominator of persons actually engaged in the field, possessed only of the knowledge and prejudices that all of them can be said to possess.
The common knowledge of different groups employed on the same tasks in different organizations is likely to be different, and It is unlikely that the
expert witnesses will be truly representative of the skilled person, as not only may they be too well qualified but they will come to the case with
personal prejudices or preferences that must be discounted:
Luxmoore J. in British Acoustic Films (53 R.P.C.221 stated: ""It is not sufficient to prove common general knowledge that a particular disclosure is
made in an article, or series of articles, in a scientific journal, no matter how wide the circulation of that journal may be, in the absence of any evidence
that the disclosure relates. A piece of particular knowledge as disclosed in a scientific paper does not become common general knowledge merely
because it is widely read, and still less because it is widely circulated. Such a piece of knowledge only becomes general knowledge when it is
generally known and accepted without question by the bulk of those who are engaged in the particular art; in other words, when it becomes part of
their common stock of knowledge relating to the Article
The correct explanation was given by the Court of Appeal in Beloit Technologies Inc v. Valmet Paper Machinery Inc (1997) RPC 489 at pages
494-495: ""The information in a patent specification is addressed to such a man and must contain sufficient details for him to understand and apply the
invention. It only lacks an inventive step if it is obvious to such a man. It follows that evidence that a fact is known or even well-known to a witness
does not establish that fact forms part of the common general knowledge. Neither does it follow that it will form part of the common general
knowledge if it is recorded in a document.
In ICI Chemicals and Polymers Ltd. v. Lubrizol Corps 45 IPR 577 Emmett J stated, ""the common general knowledge is the technical background
to the hypothetical skilled worker in the relevant art.... but also includes the material in the field in which he is working which he knows exists and to
which he would refer as a matter of course.
Thus from the above cases, common general knowledge is the common knowledge in the field to which the invention relates. It is generally known
as common knowledge and regarded as a good basis for further research activity by those engaged in that art before it becomes part of their common
stock of knowledge relating to the art, and then becoming part of the common general knowledge. Therefore it means the information which at the
date of the patent in question is known and accepted without question by those who are engaged in the art or science to which the alleged invention
relates. It would also appear therefore, that when it is a question of common general knowledge i.e, knowledge available in a country for a long time,
which every skilled worker in that field is, expected to know. Then such knowledge would be sufficient to invalidate a patent. Again such knowledge
need not even be found in a particular document. In other words a patent application has to be accessed on the basis of not only what will be available
from prior documents but also from the common general knowledge on the subject, which may or may not be available in any such document. It can
be taken as a well settled principle, that the common general knowledge is a knowledge that must be attributed to a skilled person, without which he
may not be taken to be a skilled person in the Article Therefore it is a knowledge that every skilled person should acquire before he embarks on the
problem for which the patent provides the solution. A patent can therefore be taken to be addressed to the skilled addressee, someone skilled in the
subject matter of the invention. It is also important to differentiate between matter which was in the public domain at the priority date of the patent and
matter which can properly be regarded as common general knowledge. Evidence that a particular fact is known or even well-known to a witness does
not mean that it is common general knowledge. Likewise, a piece of information disclosed in a scientific paper does not become common general
knowledge merely because it is widely read. On the other hand, it is not necessary to show that the information is known in the sense that the skilled
person has memorized it. Material which is known to exist and to which the skilled person would refer as a matter of course if he cannot remember it
is clearly part of the common general knowledge.
Skilled person in the art
A patent specification is addressed to those likely to have a practical interest in the subject matter of the invention, and such persons are those
with practical knowledge and experience of the kind of work in which the invention is intended to be used. The addressee reads the specification with
the common general knowledge of persons skilled in the relevant Article He is unimaginative and has no inventive capacity. So a patent must be
considered through the eyes of the notional person skilled in the Article The 'notional skilled person' who is the addressee of the specification is
normally described in various ways for various purposes. The skilled person is essentially a legal construct, and not a mere lowest common order of all
the persons engaged in the art at a particular time.
The Respondent shall disclose all the features of the invention in the specification, without any ambiguity, in return to the exclusive monopoly right
which is granted to him. A patent can be granted only when all the three following criteria are satisfied or complied with. They are,
i. New and useful
ii. Inventive step or non-obviousness
iii. Capable of industrial application
The first criterion is the novelty of the product, which is to be patented. Novelty is not defined in the Indian law, but the 'invention' and ""inventive
step"" are defined as below under Section 2(1)(j) and 2(1) (ja) of the Act respectively;
(j) ""invention means a new product or process involving an inventive step and capable of industrial application;
(ja) ""inventive step"" means a feature of an invention that involves technical advance as compared to the existing knowledge or having economic
significance or both and that makes the invention not obvious to a person skilled in the art;
The applicant has argued by referring to US patent 4,150,301 in respect of Novelty and US patents 1,802,094 in respect of obviousness and lack of
inventive step and we consider only those arguments made before us relying on the specific grounds taken by them as they have not taken the other
grounds during the hearing.
Novelty
The novelty as per the reported case laws could be defined as below; An invention shall be taken to be
New if it does not form part of the state of the art or the available prior Article
1 The state of the art in the case of an invention shall be taken to comprise all matter (whether a product, or a process, information about either, or
anything else) which has at any time before the priority date of that invention been made available to the public (anywhere in the world) by written or
oral description, by use or in any other way.
The law of novelty is concisely stated by Lord Hoffmann in Smithkline Beecham plc's (Paroxetine Methanesulfonate) Patent (2005) UKHL 59;
(2006) RPC 10. In summary, and for present purposes:
(1) There are two requirements for anticipation which is very important to consider separate, (a) disclosure and (b) ennoblement ;
(2) So far as the disclosure is concerned, the prior art must disclose subject matter which, if performed, would necessarily result in an infringement of
the patent.
The law of novelty was again explained by the House of Lords in Synthon v. Smithkline Beecham (2005) UKHL 59 : (2006) RPC 323 the
specification should meet two requirements. First, the matter relied upon as prior art must disclose subject matter which, if performed, would
necessarily result in an infringement of the patent. Second, that disclosure must have been enabling, that is to say the ordinary skilled person would
have been able to perform the invention if he attempted to do so by using the disclosed matter and the common general knowledge.
We feel it is very pertinent to rely upon the equally well-known statement of Lord Westbury in Hills v. Evans (1862) 4 De G.F. and J. 288 at 301:
The information given by the prior publication must, for the purposes of practical utility, be equal to that given by the subsequent patent.
We quote here the judgment of the Sachs LJ with the classic statement in General Tire (1972) RPC 457 at p.485:
To determine whether a patentee's claim has been anticipated by an earlier publication it is necessary to compare the earlier publication with the
patentee's claim. The earlier publication must, for this purpose, be interpreted as at the date of its publication, having regard to the surrounding
circumstances which then existed, and without regard to subsequent events. .... If the earlier publication, so construed, discloses the same device as
the device which the patentee by his claim, so construed, asserts that he has invented, the patentee's claim has been anticipated, but not otherwise.
In Flour Oxidising v. Carr 1908) 25 RPC 428 , line 34, approved in BTH v. Metropolitan Vickers (1928) 45 RPC 1 , line 1); (General Tire and
Rubber Co v. Firestone Tyre and Rubber Co Ltd (1972) RPC 457 at 486)"" It was held that to prove anticipation:
A signpost, however clear, upon the road to the patentee's invention will not suffice. The prior inventor must be clearly to have shown to have planted
his flag at the precise destination before the patentee.
L J Sachs in General Tyre and Rubber Co. v. Firestone Tyre Co. (1972) RPC 4567 at page 485, held:
for anticipation to occur the antecedent document must contain clear and unmistakable directions to do what the patentee has claimed in the claim
under consideration.
The best known statement of status and function of claims in a patent specification, is given by Lord Russell of Killowen in Electric and Musical
Industries Ltd v. Lissen Ltd. (1938) 56 RPC 23, 39: ""The function of the claims is to define clearly and with precision the monopoly claimed, so that
others may know the exact boundary of the area within which they will be trespassers. Their primary object is to limit and not to extend the monopoly.
What is not claimed is disclaimed. The claims must undoubtedly be read as part of the entire document and not as a separate document; but the
forbidden field must be found in the language of the claims and not elsewhere.
We shall analyse all the relevant claims as regards novelty first. There are 8 claims of which claims 2 to 8 are depended on the principal claim 1.
The claim 8 is the omnibus claim.
Claim 1 reads as below:
A rotor blade for a wind power installation, the rotor blade divided longitudinally into a two integrally connected portions, a first one of the portions
being closer to a root of rotor blade and second one of the portions having farther from the root of the rotor blade, the first portion having a first angle
of attack so that a power coefficient of the first portion is maximized at a first high-speed index, the second portion having a second angle of attack,
different from the first angle of attack, so that a power coefficient of the second portion is maximized at a second high-speed index, wherein the
second high-speed index is greater than the first high-speed index.
According to the Respondent, High Speed index (?) is defined as Vtip/Vwind. It is submitted that Vtip is equal to rotational velocity of the blade in
radius per unit time multiplied by the radial length of the blade. The Respondent has stated in his counter statement that there is only one tip speed (V
tip ) for each rotor blade. At any given point of time, the Vwind and Vtip will be constant over the entire length of he blade. As such, the high speed
index will also be constant over the entire length. But this is contrary to claim 1 where it is claimed that the blade has two different values of high
speed index, one near the root and the other near the tip. The applicant has cited US 4,150,301 (hereinafter referred to as US '301) as anticipating the
claim 1 of the impugned patent. It was pointed out by the applicant that US '301 patent relates to wind turbine with rotor blades having two portions
which have been described as blade systems. These blade systems have been longitudinally situated and have different tip speed ratios (equivalent to
high speed index) at which they reach their maximum efficiencies. It was also pointed out by the applicant that the tip speed ratio of the outer portion
at which it reaches maximum efficiency is greater than that of the inner portion (column 7, lines 40-48 read with figure 7 of US 301 Patent). Further,
the applicant pointed out that the object of US '301 Patent and impugned Patent is same as both the patent aims to achieve the maximum power
efficiency. The Respondent's only argument is that the US '301 patent discloses two rotor blades and not one rotor blade with two portions. The
applicant's argument is that claim 1 claims a rotor blade having two integrally connected portions and US '301 patent also discloses two integrally
connected blade portions and hence claim 1 is anticipated by prior Article As per the Respondent the rotor blade is designed having two portions with
different angle of attack such that the power coefficient is high for a portion of the rotor blade at a particular high speed index. From the Fig. 3 shown
earlier, it is noticeable that the blade shown in this figure of the impugned patent is similar to the blade construction shown in US '301 patent where as
from the Fig. 5 shown earlier, there is a minor variation or a difference between the impugned patent and the cited US '301 patent, showing the
integrally connected nature between the two portions of the blade. Nevertheless the contention of the Respondent that there will be only one tip speed
so as to have one high speed index for the rotor blade is not acceptable and it is misleading, when they are claiming in claim 1 clearly two different
high speed index namely first high speed index for the first portion and the second high speed index for the second portion of the rotor blade. It is also
clear from the amended claim 1 of the US '301 patent which is a granted patent equivalent to the impugned patent. This fact is also clear that the very
same cited US '301 patent has been cited against the US claims of the application filed as equivalent to impugned patent and the US claims have been
amended accordingly. Further, as per the submission of applicant it is seen the blade portion 16 and 22 are contiguous though not the blades are
connected integrally to be made in the form of one piece it is designed to perform substantially the same function in substantially the same way to
achieve the same result. In the said US '301 patent the function is to provide high speed index by way of angle of attack, and the result is to maximize
the power coefficient.
From the claim 1 of the impugned patent the following elements are seen:
i. Longitudinally divided blade to have two integrally connected blade portion;
ii. First portion being closer and closer portion being farther from the root;
iii. First portion having first angle attack so that its power coefficient is maximized at first high speed index;
iv. Second having a different angle of attack so that its power coefficient is maximized at second high speed index;
v. Second high speed index is greater than first high speed index
As can be seen below, all the elements of the test of doctrine of equivalence for each of the elements of the claim are established.
 (Editor: The text of the vernacular matter has not been reproduced. Please write to contact@manupatra.com if the vernacular matter is
required.)
Now considering the comments from the Respondent's expert, Mr. Bernd Steckemetz, aged 55 years holds a degree in Aeronautical and Space
Engineering and a Doctoral degree in Aeronautical and Space Engineering having 28 years of experience working in Aeronautical and Space
Engineering in the field of Aerodynamics and Flight Dynamics, including projects regarding wind turbines. This expert says that US '301 patent
describes a wind energy plant rotor wherein the inner rotor blades are connected to each other at their blade tips by a circular ring structure. This
circular ring structure is necessary to provide the mounting stiffness for the three outer blades. There is no transition between the inner and outer
blades. The pitch angle of the outer blades is variable due to the centrifugal mass, i.e. the orientation is depending on the rotational speed of the rotor
system.
Considering the comments of the expert of the applicant Mr. K. Manjunatha Udupa, aged 60 years holds a Bachelor degree in Mechanical
Engineering from Mysore University and a Masters Degree in Aeronautical Engineering from the Indian Institute of Science, Bangalore and
thereafter a Ph.D. in Aero Space Engineering from the Indian Institute of Technology, Chennai and having 37 years of experience of working in the
field of design and development of aircraft structure and helicopter rotor in Hindustan Aeronautics Limited, Bangalore. He has also worked as a
designer and project coordinator for the development of fibre composite rotor blade for 250 kw wind turbine. This expert has said that the claims are
anticipated by prior art and there is no inventive feature in any of the claims and further the claim 1 is incorrect as the blade has only one tip to have a
particular wind speed; then it will have only one high speed index. Then the expert has said that the Respondent has made contradictory statements in
his reply at para 7.8. Claim 1 claims two different high speed indexes whereas the Respondent states in his reply that there is only one tip speed for
each rotor blade. If there is only one tip speed for each rotor blade then there cannot be two different high speed indexes as claimed by the
Respondent in claim 1. As admitted by the Respondent that there is only one tip speed thus, claim 1 is wrong. Further the expert has commented in
respect of the cited US '301 patent, that the structural rim (20) acts as a transition between the outer and inner blade segments. In the rotor blade of
the US '301 patent the concept of two portions and transition between the two portions is existing. Claim 1 which states that the first portion has a first
angle of attack and the second portion having a second angle of attack is a sub set of the arts explained in US '301 patent. Hence, according to him a
person who is skilled in the art will be able to utilize the concept of US '301 patent and derive a new rotor blade with different portions having different
speed indexes with the objective of achieving maximum power efficiency.
Considering the expert affidavit of the applicant Mr. Kunal Ghosh, aged 64 years, holds a B. Tech. degree from IIT, Kharagpur in Aeronautical
Engineering and holds a Ph.D. degree in Aeronautics and Astronautics from University of Southampton, UK and presently working as a Professor in
IIT, Kanpur. This expert has commented that standard terminologies as used in technical literature of wind turbines have not been used in the
complete specification of the impugned patent for example
i. In paragraph 1 of internal page 2 of the patent specification, it is indicated that, Veff is vector sum of Vwind and Vtip. However in fig 1, Veff is
shown as vector sum of Vwind and negative of Vtip. This is a contradiction between his text and Fig 1.
ii. Equation 1 is incorrect. This being a vector sum, the square root should be extended over both the terms
iii. It is clear from page 2, lines 10 - 12, that afflux angle and angle of attack are different although angle of attack has not been defined here. On page
9, lines 20 to 21, the statement implies that the angle of attack is the angle between the profile chord and the wind direction. This makes angle of
attack identical to afflux angle. There is thus a contradiction between relevant statements in page 2 and page 9.
iv. In page 2, where all major terms and definitions are given, there are numerous inconsistencies and errors. Also in subsequent pages, here are
contradictory statements as illustrated above. Hence a person skilled in the art will be unable to understand it and work the patent.
Mr. Kunal Ghosh further observed that the Respondent has mentioned in his counter statement, there is only one tip speed for each rotor blade. The
fact remains that any blade can have only one tip. If there is only one tip, there can be only one tip speed for each rotor blade; then there can not be
two different high speed indexes as claimed by the Respondent in his claim 1. Therefore the Respondent while indicating two different high speed
indices for the same blade is contradicting himself as any blade has only one tip and only one tip speed ratio for a given wind speed. As against
anticipation ground, Mr. Kunal Ghosh has commented that claim 1 has following elements as features as given below:
i. Longitudinally divided blade to have two integrally connected blade portions;
ii. First portion being closer and second portion being farther from the root;
iii. First portion having first angle attack so that its power coefficient is maximized at first high speed index;
iv. Second having a different angle of attack so that its power coefficient is maximized at second high speed index;
v. Second high speed index is greater than first high speed index
In respect of feature (i) above, referring to the US '301 patent he submitted that the first portion i.e. blade 22 is contiguously connected to the second
portion i.e. blade 16. Moreover, as can be seen from Figure 1 the blade 22 and blade 16 are also longitudinally connected through a rim 20 (i.e.
transition region). Then in respect of feature (ii) above, Mr. Ghosh said that figure 1 in US '301 patent demonstrates that the blade portion 16 is nearer
to the hub 12 i.e., closer to the root and the blade portion 22 is farther from the hub 12 i.e. farther from the root (column 4, lines 6-29). Then in respect
of features (iii and iv) above referring to figure 6 of US '301 patent demonstrates that the blade portion 16 and the blade portion 22 have different pitch
angles. Notably, the angle of attack as defined in the impugned patent is the angle between the chord and the wind direction (page 9, line 18 of the
patent specification). Referring to column 6, line 19 of the US '301 patent Mr. Ghosh stated that the pitch angles are varied along the length of the
blade system to achieve a desired angle of attack. Further that can be seen from claim 2, column 10, lines 12 to 25 of the US '301 patent discloses a
first angle of attack for blade system 16 and second angle of attack for blade system 22. Similarly referring to fig 7 of the US '301 patent Mr. Ghosh
said the blade systems have corresponding speed ratios (high speed index) corresponding to maximum power efficiency (that is power coefficient).
More specifically, the blade portion 16 and the blade portion 22 have a different tip speed ratio at which their power coefficient is maximized. Then in
respect of feature (v) above referring to figure 7, column 7, lines 40 - 48 of the US '301 patent discloses that the tip speed ratio of blade 22 is in range
of 6.0 to 8.0 that is greater than the tip speed ratio of blade 16 which is approximately 2.0. Therefore in view of the above Mr. Kunal Ghosh said the
US '301 patent anticipates the claim 1 of the impugned patent.
Now, after considering the views and comments of the experts of both the parties and their arguments from their side and also taking into
consideration of the analysis made in para 43 ante, there being existing a minor difference in the particular construction aspect of the rotor blade, as
seen, between the citation and the impugned patent, though the cited US '301 patent shows most of the features of the impugned patent otherwise, we
find that the US '301 patent does not stand as a prior anticipating document on account of the construction aspect only, which is mentioned above, to
attack the novelty of the feature claimed in claim 1 of the impugned patent. As held in Hills v. Evans (1862) 4 De G.F. and J. 288 at 301 and General
Tire and Rubber Co v. Firestone Tyre and Rubber Co Ltd. (1972) RPC 457 at 486, supra, ""to anticipate a patent, a prior publication or activity must
contain the whole of the invention impugned, i.e. all the features by which the particular claim attacked is limited. In other words, the anticipation must
be such as to describe, or be an infringement of the claim attacked."" It is a well settled law that a prior art reference cited anticipates the claim when
its limitations are not expressly found in that reference but are nonetheless inherent in it. Under the principle of inherency, if the prior art necessarily
functions in accordance with, or include the claimed limitations, it anticipates. Whereas here in this case, the main principal claim1 is found not
anticipated by the US '301 patent and the principal claim1 remains. Then the subordinate claims which are in one way or the other, dependent on the
principal claim1 would also be normally not anticipated by this US '301 patent, as all those claims are found to have minor variations in features from
the features seen here in the principal claim 1. In view of the above analysis and findings herein, we find that the US '301 patent does not stand as an
exact anticipation document to affect the novelty requirement and therefore the objection by the applicant on this ground fails.
Obviousness
We shall see the claims of the impugned patent with respect to obviousness or lack of inventive step. A patent will be invalid for lack of inventive
step if the invention claimed in it was obvious to a person skilled in the art having regard to the state of the art at the priority date. In fact at the date of
the patent, the US '437 patent and the US '419 patent are already known to the public knowledge and the person skilled in the art must be aware of
the said patents as the former patent forms part of the common general knowledge, being an old prior art of more than 12 years by then, and the later
patent being part of the latest developments in the field.
The test to ascertain whether an invention involves an inventive step is expressed in Halsbury Laws of England as: 'was it for practical purposes
obvious to the skilled worker, in the field concerned, in the state of knowledge existing at the date of the patent to be found in the literature then
available to him, that he should or would make the invention the subject of the claim concerned.' In other words, the question to be answered in
determining inventive step is 'Would a non-inventive mind have thought of the alleged invention?' If the answer is 'no', then the invention is non-
obvious. If the patent claimed merely includes the development of some existing trade, in the sense that it is a development as would suggest itself to
an ordinary person skilled in the art, it would fail the test of non-obviousness.
Let us analyse claims and particularly claim 1 first as regards its inventive features.
The main inventive features as claimed in claim1 are as below:
i. Longitudinally divided blade to have two integrally connected blade portion;
ii. First portion being closer and second portion being farther from the root;
iii. First portion having first angle attack so that its power coefficient is maximized at first high speed index;
iv. Second portion having a different angle of attack so that its power coefficient is maximized at second high speed index;
v. Second high speed index is greater than first high speed index
The applicant submitted that claim 1 is obvious in the light of US '301 Patent and U.S. Patent 1802094 (hereinafter US '094 Patent ) and stated
that it has been shown in previous submissions towards novelty aspect, that '301 Patent describes a rotor blade of a wind turbine, which has two
portions (14 and 18 in Fig. (1) having different 'tip speed ratio ' (same as high speed index) at which they achieve their respective maximum efficiency,
wherein the said tip speed ratio of the outer portion is greater than that of the outer portion (Column 7, lines 40-48, read with Figure 7 of US '094
patent). Even assuming the applicant stated that without admitting the fact US '301 Patent does not anticipates Claim 1, those skilled in the art, would
easily gather the same idea from US '094 Patent. This patent discloses a blade structure, wherein the blade has multiple angles of attack, by virtue of
warping and is formed in a single construction. It has various intermediate angles, ranging from 1 degree to 40 degrees. (Page-1, lines 77-80, of
US'094 Patent). Referring to Figure 2 the said intermediate angles can be noticed. From the above disclosures it would not be difficult for those skilled
in the art to combine these two prior arts and be motivated to make a rotor blade with integral construction but with different portions having different
high speed indexes at which the respective portions attain their maximum efficiencies. Therefore, he submitted that the invention claimed in Claim 1
cannot be said to be inventive and is obvious.
The Respondent submitted that patent US 1,802,094 (herein after referred to as US '094 patent) describes two rotor blades to be used at a wind
energy plant. The first is intended for use in a wind turbine with only one rotor blade, whereas the second with two blades. Therefore the rotor blades
are composed of different blade profiles because of their different nominal rotation speeds. The twisted orientation of the profiles starting with a large
angle of incidence near the rotor hub and showing a continuous decrease of the angle of incidence towards the rotor tip is a general state-of-the-art
feature of any propeller and rotor design. Due to the variation of the linear speed in radial direction, this rotor twist is necessary to overcome the
stalling effects in the outer radial portion and the too low or even negative without twist. This would result in a very inefficient aerodynamic force
distribution across the rotor plane.
The Respondent submitted that US '094 further discloses on page 1, columns 84 and 85 that the blade has a no-load tip-speed-ratio of 11.
Accordingly, the complete blade has one single tip speed ratio. Further considering the fact that the US '094 is directed to high speed turbines or high
speed wind turbines, it is clear that the rotor blade is optimized with respect to this high speed and providing an optimized air foil. In fact, US '094
clearly describes on page 1, lines 80 to 84 that a good air foil is assumed. Accordingly, both documents US '301 are directed to completely different
objects.
In the present invention, the Respondent submitted that the object is to make a rotor blade less sensitive to turbulent wind flows. None of the
documents US '301 and US '094 provide any solution to this problem. In addition, none of these documents discloses an improvement of a rotor blade
design in this respect. Accordingly, the person skilled in the art will neither find any indications of the problem nor any indications for a solution in the
cited documents US '301 and US '094. Therefore in view of the above, the Respondent submitted that the subject-matter of claim 1 is inventive in
view of US '301 and US '094.
Now analysing the claims in the specification of the impugned patent according to the patent specification drafting the inventive step is in the post
characterising clause"" or after the words ""wherein"" clause and then the only inventive feature according to the impugned patent, the step at (v) which
only can be taken as the inventive step. It is the system followed in EPO as well as USPTO and in India. But the Respondent has been contesting that
the whole features given in the claim1 are the inventive step. Now that there being only one feature available, considering the whole claim as per the
Respondent view, and after considering above observations together with the views and comments given by the experts of both the applicant and
Respondent, it is noticed that in respect of feature (i) above, teachings of the US '301 patent shows that the first portion i.e. blade 22 is contiguously
connected to the second portion i.e. blade 16. Moreover, as can be seen from Figure 1 the blade 22 and blade 16 are also longitudinally connected
through a rim 20 (i.e. transition region). Even in the impugned patent the Respondent has not specifically explained in the specification, as to what is
this ""integrally connected"" feature regarding the two portions of the rotor blade? When comparing the figure 1 of the US '301 patent and the fig.3 of
the impugned patent as seen below:
i. Longitudinally divided blade having the integral connection of the blade portion is present in both the patents; (as well as in US '094 patent.). Further
what is the extra inventive step in this feature?
ii. First portion being closer and second portion being farther from the root; this feature is also present in both the patents as well as in US '094 patent.
iii. Then in respect of feature (ii) above, as per one of the expert of the applicant, figure 1 in US '301 patent demonstrates that the blade portion 16 is
nearer to the hub 12 i.e., closer to the root and the blade portion 22 is farther from the hub 12 i.e. farther from the root (column 4, lines 6-29).
(Editor: The text of the vernacular matter has not been reproduced. Please write to contact@manupatra.com if the vernacular matter is
required.)
iv. Then in respect of features (iii and iv) above, figure 6 of US '301 patent demonstrates that the blade portion 16 and the blade portion 22 have
different pitch angles. Notably, the angle of attack as defined in the impugned patent is the angle between the chord and the wind direction (page 9,
line 18 of the patent specification).
Referring to column 6, line 19 of the US '301 patent one of the applicant's expert stated that the pitch angles are varied along the length of the
blade system to achieve a desired angle of attack. Further that can be seen from claim 2, column 10, lines 12 to 25 of the US '301 patent discloses a
first angle of attack for blade system 16 and second angle of attack for blade system 22. Similarly referring to fig 7 of the US '301 patent it is
perceivable that the blade systems have corresponding speed ratios (high speed index) corresponding to maximum power efficiency (that is power
coefficient). More specifically, the blade portion 16 and the blade portion 22 have a different tip speed ratio at which their power coefficient is
maximized.
Then in respect of feature (v) above referring to figure 7 of the US'301 patent, column 7, lines 40 - 48 of the US '301 patent discloses that the tip
speed ratio of blade 22 is in range of 6.0 to 8.0 that is greater than the tip speed ratio of blade 16 which is approximately 2.0. One of the experts for
the applicant has deposed in respect of the cited US '301 patent, that the structural rim (20) acts as a transition between the outer and inner blade
segments. In the rotor blade of the US '301 patent the concept of two portions and transition between the two portions is existing. Claim 1 which
states that the first portion has a first angle of attack and the second portion having a second angle of attack is a sub set of the arts explained in US
'301 patent. Hence, according to him a person who is skilled in the art will be able to utilize the concept of US '301 patent and derive a new rotor blade
with different portions having different speed indexes with the objective of achieving maximum power efficiency.
Therefore in view of the above analysis, we do not find any technical advance as regards the impugned patent over the US '301 patent and US
'094 patent and neither the Respondent has clearly brought out that feature of technical advance over the cited prior art in their observations nor is
there any particular clearer description in respect of the same in the specification. There is only mere denial by the Respondent for all the objections
taken by the applicant. From the above analysis it is very clear that it would be very easy for those skilled in the art to combine these two cited US
patents and from the prior arts be motivated to make a rotor blade with an integral construction but with different portions having different high speed
indexes at which the respective portions attain their maximum efficiencies. Therefore, the invention claimed in Claim 1 does not have any inventive
step and is obvious.
We shall now consider a few case laws as regards obviousness or inventive step and particular reference is made to M/s. Bishwanath Prasad
Radhey Shyam v. Hindustan Metal Industries MANU/SC/0255/1978 : (1979) 2 SCC 511, where it was held that, ""was it for practical purposes
obvious to a skilled worker, in the field concerned, in the state of the knowledge existing at the date of the patent to be found in the literature then
available to him, that he would or should make the invention the subject of the claim concerned?
Buckley LJ in Valensi v. British Radio Corporation (1973) RPC 337, held that, "" The hypothetical addressee is not a person of exceptional skill and
knowledge, and he is not to be expected to exercise any invention nor any prolonged research, enquiry or experiment. He must, however, be prepared
to display a reasonable degree of skill and common knowledge of the art in making trials and to correct obvious errors in the specification if a means
of correcting them can readily be found and arrive at the result....
A patent will be invalid for lack of inventive step if the invention claimed in it was obvious to a person skilled in the art having regard to the state of
the art at the priority date. The familiar structured approach to the assessment of allegations of obviousness first articulated by the Court of Appeal in
Windsurfing International Inc v. Tabur Marine (Great Britain) Ltd. (1985) RPC 59; It is convenient to address the question of obviousness by using
the structured approach as explained by the Court of Appeal in Pozzoli v. BDMO (2007) EWC 588 : (2007) FSR 37. This involves the following steps:
1 Identify the notional 'person skilled in the art' and the relevant common general knowledge of that person
2 Identify the inventive concept of the claim in question or, if it cannot be done, construe it.
3 Identify if any the differences existing between the matters cited as forming state of the art and the inventive concept of the claim or the claim as
construed.
4 Ask whether, when viewed without any knowledge of the alleged invention as claimed: do those differences constitute steps which would have been
obvious to the person skilled in the art or do they require any degree of invention?
The first step is; ""who is the notional person skilled in the art in this field of wind power installation technology?
This is a person who is likely to have a practical interest in the subject matter of the invention. The relevant common general knowledge of that person
must be such as the knowledge of Aeronautical engineering as a broad specialisation with requisite experience in the wind power technology. In this
case, both the applicant and the Respondent are the person skilled in the art or otherwise such person must have the knowledge of wind power
technology.
The second step is; ""Identify the inventive concept of the claim in question
Inventive concept according to the Respondent is the principal claim 1 itself:
A rotor blade for a wind power installation, the rotor blade divided longitudinally into a two integrally connected portions, a first one of the portions
being closer to a root of rotor blade and second one of the portions having farther from the root of the rotor blade, the first portion having a first angle
of attack so that a power coefficient of the first portion is maximized at a first high-speed index, the second portion having a second angle of attack,
different from the first angle of attack, so that a power coefficient of the second portion is maximized at a second high-speed index, wherein the
second high-speed index is greater than the first high-speed index.
The third step is; ""Identify if any the differences existing between the matters cited as forming state of the art and the inventive concept of the
claim or the claim as construed"".
Inventive concept according to the Respondent is the principal claim 1 itself:
A rotor blade for a wind power installation, the rotor blade divided longitudinally into a two integrally connected portions, a first one of the portions
being closer to a root of rotor blade and second one of the portions having farther from the root of the rotor blade, the first portion having a first angle
of attack so that a power coefficient of the first portion is maximized at a first high-speed index, the second portion having a second angle of attack,
different from the first angle of attack, so that a power coefficient of the second portion is maximized at a second high-speed index, wherein the
second high-speed index is greater than the first high-speed index.
Now to identify if any the differences existing between the matters cited as forming the state of the art and the inventive concept of the claim or the
claim as construed:
Longitudinally divided blade to have two integrally connected blade portions with the second high speed index is greater than first high speed index
But it is worth checking here, as to whether these above referred feature will constitute as a technical advance over the existing technology!
Inference when such a checking is done is as follows:
Considering the arguments and the observations of the applicant and the Respondent, together with the views and comments given by the experts of
both the applicant and Respondent, it is noticed that in respect of the above mentioned feature, teachings of the US '301 patent shows that the first
portion i.e. blade 22 is contiguously connected to the second portion i.e. blade 16. Moreover, as can be seen from Figure 1 given above, the blade 22
and blade 16 are also longitudinally connected through a rim 20 (i.e. transition region). Even in the impugned patent the Respondent has not specifically
explained in the specification, as to what is this ""integrally connected"" feature regarding the two portions of the rotor blade? When comparing the
figure 1 of the US '301 patent and the fig.3 of the impugned patent it is noticed that:
Longitudinally divided blade having the integral connection of the blade portion is present in both the patents; (as well as in US '094 patent.). Further
what is the extra inventive step over the two cited patents is not clearly spelt out; probably we infer that only the minor variation or difference in the
integrally connected nature between the two portions of the blade construction."" But a person who is skilled in the art will be able to utilize the concept
of US '301 patent and US '094 patent and derive a new rotor blade with different portions having different speed indexes with the objective of
achieving maximum power efficiency.
The last step is: ""ask whether, when viewed without any knowledge of the alleged invention as claimed: do those differences constitute steps
which would have been obvious to the person skilled in the art or do they require any degree of invention?
For the lack of inventive step in the invention claimed when it is obvious to a person skilled in the art having regard to the state of the art at the
priority date of the patent application, that patent will become invalid.
Longitudinally divided blade having the integral connection of the blade portion is the particular point agitated, but that is present in the cited patents;
then what is the extra inventive step over the two cited patents is not clearly spelt out; probably it is viewed that it is possibly only the minor variation
or difference in the integrally connected nature between the two portions of the blade construction."" But a person who is skilled in the art will be able
to utilize the concept of US '301 patent and US '094 patent and derive a new rotor blade with different portions having different speed indexes with
the objective of achieving maximum power efficiency.
In view of this analysis and the finding herein, it is very clear there is no inventive step in the invention claimed in the impugned patent and the
invention claimed is obvious to any skilled person in the Article
Therefore combining the said two cited US patents, a person skilled in the art can arrive at the invention claimed in the claim 1 of the impugned
patent. Hence the invention cannot be said to have any inventive step and the invention is obvious.
As per the Act, all the claims in a complete specification will have one inventive step or making them to be having group of inventive features to have
a single inventive concept. Since that inventive step in the principal claim 1 has been shown to be obvious, all the subsidiary claims dependent on the
principal claim 1, which tend to add only minor variations of features will not impart any inventive step to the dependent claims.
Conclusions
Novelty
Considering the views and comments of the experts of both applicant and Respondent and their arguments from their side and also taking into
consideration of the analysis made in para 48 ante, there being existing a minor difference in the particular construction aspect of the rotor blade, as
seen, between the citation and the impugned patent, though the cited US '301 patent shows most of the features of the impugned patent otherwise, we
find that the US '301 patent does not stand as a prior anticipating document on account of the construction aspect only, which is mentioned above, to
attack the novelty of the feature claimed in claim 1 of the impugned patent.
Obviousness
a. Comparing the inventive features in the US '301 patent and US '094 patent, the inventive features as construed from the principal claim 1, no
difference in the invention claimed in the claim of the impugned patent could be perceived or noticed, rather it is only an obvious improvement over the
existing Article No technical advance has been established by the Respondent over the prior art as required under the law.
b. Invention claimed would be obvious to a person skilled in the art having regard to the state of the art, when no technical advance over the prior art,
is established, then the patent lacks inventive step and will become invalid.
c. In the instant case, at the date of the patent, the US '301 patent and the US'094 patent are already known to the public knowledge and the person
skilled in the art is aware of the same and any skilled person in the art, though he is unaware of this impugned patent, but with his average knowledge
and skills in the field of relevant technology will certainly be able to visualize the details of the invention and will be able to arrive at this invention, as
this a known technical knowledge, to utilize the concept of US '301 patent and US '094 patent and derive a new rotor blade with different portions
having different speed indexes with the objective of achieving maximum power efficiency.
d. In view of this analysis and the finding herein, it is very clear there is no inventive step in the invention claimed in the impugned patent and the
invention claimed is obvious to any skilled person in the Article
e. As per the Act, all the claims in a complete specification will have one inventive step or making them to be having group of inventive features but to
have a single inventive concept. Since that inventive step in claim 1 has been shown to be obvious, all the subsidiary claims dependent on the principal
claim 1, which tend to add only minor variations of features will not impart any inventive step to the dependent claims. Then the subordinate claims
which are dependent on the principal claim1 would also become invalid and does not stand as a separate independent or individual claim as no
exclusive technical improvement in the feature could be shown therein.
Hence after taking into consideration of the above said case laws and findings and analysis made herein above, together with foregoing statements
in the conclusions, we hereby allow the application for the revocation of the patent. M.P. No. 10/2010 for stay has been dismissed as nothing remains
in the miscellaneous petition as the main application has been disposed of. M.P. No. 38/2010 for early hearing is dismissed as infructuous. M.P. No.
62/10 is also dismissed. As per the directions of the Hon'ble High Court of Madras, all the miscellaneous petitions have been heard and decided along
with the main application. Consequently the patent granted to the Respondent is revoked and also direct the Controller of Patents to remove the patent
No. 198256 from the register of patents. The parties shall bear their own costs.