Ex Parte Tsypkaykin et al

Patent Trial and Appeal Board

Sep 20, 2016

13117166 (P.T.A.B. Sep. 20, 2016)

UNITED STA TES p A TENT AND TRADEMARK OFFICE
APPLICATION NO. FILING DATE
13/117, 166 05/27/2011
117185 7590 09/22/2016
ALSTOM TECHNOLOGY, LTD,
Studio Torta
C/O Buchanan Ingersoll & Rooney PC
1737 King Street, Suite 500
Alexandria, VA 22314
FIRST NAMED INVENTOR
Igor Tsypkaykin
UNITED STATES DEPARTMENT OF COMMERCE
United States Patent and Trademark Office
Address: COMMISSIONER FOR PATENTS
P.O. Box 1450
Alexandria, Virginia 22313-1450
www .uspto.gov
ATTORNEY DOCKET NO. CONFIRMATION NO.
1033275-000880 7019
EXAMINER
HANN,JAYB
ART UNIT PAPER NUMBER
2123
NOTIFICATION DATE DELIVERY MODE
09/22/2016 ELECTRONIC
Please find below and/or attached an Office communication concerning this application or proceeding.
The time period for reply, if any, is set in the attached communication.
Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the
following e-mail address( es):
ADIPDOC 1@BIPC.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte IGOR T. TSYPKA YKIN and ANDRE M. SAXER
Appeal2015-006898
Application 13/117,166
Technology Center 2100
Before ERIC B. CHEN, JEREMY J. CURCURI, and
GREGG I. ANDERSON, Administrative Patent Judges.
ANDERSON, Administrative Patent Judge.
DECISION ON APPEAL
Appellants appeal under 35 U.S.C. § 134(a) from the Examiner's
rejection of claims 1, 3, and 5. 1 Claims 2 and 4 were cancelled previously.
We have jurisdiction under 35 U.S.C. § 6(b).
We affirm.
1 In this Opinion, we refer to the Appeal Brief ("App. Br.," filed February 2,
2015), the Reply Brief ("Reply Br.," filed July 15, 2015), the Final Office
Action ("Final Act.," mailed May 29, 2014), and the Examiner's Answer
("Ans.," mailed May 15, 2015), and the original Specification ("Spec.," filed
May 27, 2011).
Appeal2015-006898
Application 13/117,166
STATEMENT OF THE CASE
A. The Invention
Appellants' invention relates gas turbine blades and the surrounding
shroud. Spec. ,-i 2. Specifically, Appellants disclose a method for producing
a turbine blade that optimizes the contact surfaces between the interlocking
surfaces of the abutting shroud segments of adjacent blades of a rotor blade
row. Id. at ,-i 7. The narrowly delimited contact surfaces with high pressure
stresses can be reliably avoided without forfeiting the necessary sealing
tightness between the adjacent shroud segments. Id.
More specifically, the invention takes into account deformation of the
blade attached to the shroud resulting from operation induced loads,
including pressure variations between shroud segments. Spec. ,-i 15. The
loads of interlocking adjacent shroud surfaces in an unloaded state does not
take deformation into account. Id. Design of the blades according to the
invention maintains contact over a large area between the adjacent
interlocked shroud segments in the loaded state. Id.
Independent claim 1, reproduced below, is illustrative:
1. A method for optimizing the contact surfaces of abutting
shroud segments of adjacent blades of a rotor blade row of a gas
turbine, the method comprising the steps of:
a) providing a 3-D model of an individual blade, the
individual blade including a shroud segment delimited in a
circumferential direction by contact surfaces including an
interlocking surface and wedge surfaces disposed on each side
of the interlocking surface, the interlocking surface and wedge
surfaces being arranged in a zig-zag manner;
b) calculating a geometry of the individual blade based
on the 3-D model using a computer, the calculating including
consideration of centrifugal forces, temperature stresses,
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pressure loads experienced in a loaded state of the blade during
operation, material used for the blade, blade wall thicknesses,
blade length, blade shape and operating location of the
individual blade in combination with adjacent blades;
c) optimizing the contact surfaces within the 3-D model,
including the interlocking surface and wedge surfaces, of the
abutting shroud segments of adjacent blades in the
loaded state of the blade such that the optimized adjacent
respective interlocking surfaces and wedge surfaces are
substantially parallel and so as to avoid an increase in
contact pressure between the respective contact surfaces as a
result of ensuing operating temperature of the blades;
d) determining a geometry of the interlocking surfaces
and of the wedge surfaces in an unloaded state corresponding to
the optimized contact surfaces in the loaded state of the blade
within the 3-D model; and
e) producing a blade for a rotor blade row of a gas
turbine according to the determined geometry.
B. The Rejections
Claims 1, 3, and 5 are rejected under 35 U.S.C. 103(a) as being
unpatentable over Boegli et al (US 2007 /0231143 A 1, published Oct. 4,
2007); Durcan (US Patent 6,223,524, issued May 1, 2001); and Paquet et al
(US 2005/0079058 Al, published Apr. 14, 2005). Final Act. 4-17.
C. Issue
Only those arguments actually made by Appellants in the Briefs have
been considered in this Decision. Arguments that Appellants did not make
in the Briefs are waived. See 37 C.F.R. § 41.37(c)(l)(iv)(2012).
Appellants' arguments present the following issue:
Has the Examiner erred by finding that the combination of Boegli,
Durcan, and Paquet teaches or reasonably suggests "optimizing the contact
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Application 13/117,166
surfaces within the 3-D model ... of the abutting shroud segments of
adjacent blades in the loaded state of the blade such that the optimized
adjacent respective interlocking surfaces and wedge surfaces are
substantially parallel," as recited in claim 1 under 35 U.S.C. § 103? App.
Br. 6-11.
ANALYSIS
Independent claim 1, reproduced above, is a method claim including
steps a, b, c, d, and e. Appellants contest only step c of claim 1. App. Br. 6-
11, see also Reply Br. 2 ("The arguments in Appellants' Appeal Brief
regarding the contacts surfaces are primarily directed to pointing out that the
Boegli publication relates to an optimization of the relation of the contact
surfaces to other contact surfaces and not to optimization of the contact
surfaces themselves.").
A. Overview of Prior Art
The Examiner finds Boegli teaches adjusting the gaps, i.e., "contact
surfaces," between adjacent shroud segments of blades in a turbomachine.
Final Act. 4 (citing Boegli ii 3). The Examiner also cites to Boegli's
teaching that the gaps are reduced during operation. Id. (citing Boegli ii 11 ).
The Examiner quotes from Boegli that "the shroud elements of the blades
are thus adjacent to one another and thus form a shroud which is closed on
the circumference" (Boegli ii 3) and thus "delimited in a circumferential
direction," as recited in claim 1. Id.
The Examiner cites to Durcan which, in the context of turbine blades,
teaches:
[U]sually the blade geometry and disk geometry are complex
with non-uniform stress and temperature distributions. A Finite
Element Model (FEM) and Finite Element Analysis (PEA) are
often used to determine the blade and disk stress distributions,
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temperature distributions, and blade tip radial deflection at
various operating conditions.
Final Act. 4-5 (quoting Durcan 6:54-60). The Examiner asserts that "[a]
Finite Element Model of a blade is a 3D model." Id. at 5. Appellants do not
contest this finding by the Examiner.
Paquet is concerned with "determining a desired shroud design for a
given turbine blade design." Paquet ,-i 10. Paquet's Figures 2 and 3 show
contact faces of a turbine blade shroud arranged in a zigzag pattern. Id. ,-i 21,
Figs. 2, 3. The Examiner relies on the preceding disclosures of Paquet to
show "the interlocking surface and wedge surfaces being arranged in a
zigzag manner," as recited in claim 1.
B. Optimizing the Contact Surfaces
As set forth above, the issue here is the "optimizing the contact
surfaces" limitation, step c of claim 1. Boegli teaches "[a Jn inclination
angle of 0° means that the platform2 section which is arranged at an
inclination angle abuts against the platform section of the adjacent blade
without any step being formed." Boegli ,-i 24 (emphasis added). The
Examiner relies on this disclosure in Boegli to contend "[t]he inclination
angle and the platform sections are interlocking surfaces because they abut."
Final Act. 7.
Boegli further describes an additional inclination angle a "chosen
such that an effective additional inclination angle a-eff of more than 0° is
produced during operation of the blade." Boegli ,-i 59, lines 5-9 (emphasis
added). The Examiner contends that "during operation" is in the loaded
2 Boegli describes the shroud elements as "platforms." See Boegli ,-i 3 ("The
shroud elements are generally in the form of platforms and extend
essentially at right angles to the blade longitudinal direction.")
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Application 13/117,166
state. Final Act. 7. The Examiner cites to the Durcan disclosure of the 3D
model. Id.
Step c further recites "and so as to avoid an increase in contact
pressure between the respective contact surfaces as a result of ensuing
operating temperature of the blades." Boegli teaches that "the shrouds,
particularly for turbine stages, are often additionally subject to very high
temperature from the main flow." Boegli ii 7, lines 1-3. The Examiner
finds that temperature during operation is expressly considered. Final Act.
8. The Examiner notes that Boegli "does not explicitly disclose optimizing
or adapting to avoid contact pressure as a result of operating temperature"
but relies on the following disclosure from Durcan:
Preferably, the ring 30 is sized so that the amount of interfering
contact between the ring 30 and the blade tip 25 is at a
maximum at assembly and near an acceptable minimum during
operation. A ring 30 having minimum interfering contact
during operation will also have a total stress which is at a
mimmum, thereby providing a ring 30 which max1m1zes its low
cycle fatigue life.
Final Act. 8 (quoting Durcan, 6: 12-32).
The Examiner finds Boegli considers that temperature during
operation is expressly considered, i.e., "the shrouds ... are often additionally
subject to very high temperatures." Final Act. 8 (citing Boegli ii 7). The
Examiner finds the person of ordinary skill in the art would have been
motivate to "minimiz[ e] interfering contact and total stress during operation
into the system of designing a turbine blade with a shroud for the purpose of
maximizing low cycle fatigue life." Id. (citing Durcan, 6: 12-32).
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Appellants acknowledge Boegli's additional inclination angle, a,
"relates to an optimization of the relation of shroud elements to other shroud
elements." App. Br. 6-8. However, Appellants contend "[t]he Boegli
publication does not specifically disclose contact surfaces." Id.; see also
Reply Br. 2 (Boegli "is not concerned with the optimization of the contact
surfaces themselves."). Optimization of the inclination angle is not
optimizing the surface geometry, as per claim 1. Reply Br. 3. The gap
between shrouds, according to Appellants, is not completely closed in
Boegli. App. Br. 7-8 (citing Boegli ii 59, Fig. 3b ).
Appellants argue Durcan discloses a "continuous shroud ring and not
a segmented shroud ring." App. Br. 9-10 (citing Durcan, Fig. 3). As a
result, Durcan' s ring is "self-supporting and is not arranged on the blade
tips." Id. at 9 (citing Durcan 5:40 et seq.); Reply Br. 3. Further, Appellants
argue, Durcan' s Finite Element analysis "determine[ s] the blade and disk
stress distributions, temperature distributions, and blade tip radial deflection
at various operating conditions" and not "to optimize contact surfaces of
abutting shroud segments." App. Br. 10; Reply Br. 4.
Appellants acknowledge Paquet' s shroud is designed with a constant
thickness "[t]o achieve a desired level of contact stress." App. Br. 10-11.
Appellants also note "the thickness of one or both contact faces '40'
increases to increase the contact area and reduce the contact stress
accordingly." Id. (citing Paquet, Fig. 4).
We agree with the Examiner that abutting adjacent shrouds results in a
contact surface. See Ans. 2. The Examiner relies on that portion of Boegli
which discloses that platform sections abut each other. Id. (citing Boegli
ii 24). The fact that Boegli's Figure 3b shows there is a gap between shrouds
is of no avail to Appellants. Boegli's Figures 3a and 3b illustrate how a ("a"
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in Fig. 3a) is designed so that during operation it is reduced to a-eff ("a-eff'
in Fig. 3b ). The written description in paragraph 59 of Boegli, which is
relied on by the Examiner, states that during operation the "effective
inclination angle a-eff' is 0°. Boegli ii 59; see also Boegli ii 60 ("The
centrifugal force bending which acts on the pressure-side platform section
admittedly reduces the offset a to an effective offset a-eff, although it does
not initially return to zero." (emphasis added)).
The Examiner concludes a person having ordinary skill in the art at
the time of the invention would have been motivated to combine Durcan and
Boegli. The finite element modeling taught by Durcan would have been
used in the "designing a turbine blade with a shroud for the purpose of
'determin[ing] the blade and disk stress distributions, temperature
distributions, and blade tip radial deflection at various operating
conditions."' Ans. 5 (citing Durcan 6:58-60). The motive for the
combination is rationally based and is not specifically contested by
Appellants. Accordingly, Appellants' argument that Durcan does not
specifically relate to designing contact surfaces is not persuasive.
Appellants' arguments relating to Paquet are not relevant to the
finding of the Examiner regarding "optimizing the contact surfaces." Paquet
shows, and Appellants do not dispute, "the interlocking surface and wedge
surfaces being arranged in a zig-zag manner" of claim 1. See Final Act. 5
(citing Paquet, Figs. 2, 3).
We sustain the Examiner's rejection of claim 1.
C. Claims 3 and 5
Appellants make no additional arguments relating to claims 3 and 5,
contending they are patentable for reasons similar to those discussed in
connection with claim 1. App. Br. 11; Reply Br. 4-5.
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We therefore sustain the Examiner's rejection of claims 3 and 5.
CONCLUSION
The Examiner did not err in rejecting claims 1, 3, and 5 under§ 103.
DECISION
The Examiner's decision rejecting claims 1, 3, and 5 is affirmed.
No time period for taking any subsequent action in connection with
this appeal maybe extended under 37 C.F.R. § l.136(a)(l)(iv).
AFFIRMED
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