Ex Parte Devore et al

Patent Trial and Appeal Board

Mar 13, 2013

11529113 (P.T.A.B. Mar. 13, 2013)

UNITED STATES PATENT AND TRADEMARK OFFICE
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BEFORE THE PATENT TRIAL AND APPEAL BOARD
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Ex parte MATTHEW A. DEVORE, JOSEPH W. BRIDGES JR., and
CORNEIL S. PAAUWE.
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Appeal 2010-006760
Application 11/529,113
Technology Center 3700
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Before PHILLIP J. KAUFFMAN, MICHAEL L. HOELTER, and
JILL D. HILL, Administrative Patent Judges.

HILL, Administrative Patent Judge.

DECISION ON APPEAL

STATEMENT OF THE CASE
Matthew A. Devore et al. (Appellants) seek our review under 35
U.S.C. § 134 of the Examiner’s decision rejecting claims 1, 3, 5, and 6.
App. Br. 2. Claims 1, 3, 5, and 6 are independent claims. We have
jurisdiction under 35 U.S.C. § 6(b).
We AFFIRM.
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THE INVENTION
Appellants’ claimed invention relates to impingement cooling of a
large platform-to-airfoil fillet radius on a turbine airfoil. Spec. 1, para.
[0002]. Claims 1 and 5 are method claims, claim 3 is directed to a system
for impingement cooling, and claim 6 is directed to a turbine airfoil. Claim
1 is illustrative of the subject matter on appeal and is reproduced below with
the key disputed limitations emphasized.
1. A method of impingement cooling a
turbine airfoil with a large platform to airfoil fillet
radius which contains a plurality of cooling holes
through the airfoil wall which comprises:
(a) coring the airfoil fillet such that the fillet
wall is maintained at a minimum thickness;
(b) inserting into the airfoil an impingement
tube which follows the fillet contour to platform
transition;
(c) applying impingent air through the
impingement tube to the airfoil walls and
(d) using the impinged air to subsequently
flow through airfoil and fillet holes to provide film
cooling to the airfoil fillet.

THE EVIDENCE
The Examiner relies on the following evidence:
Cunha US 2006/0083613 A1 Apr. 20, 2006
Harding US 2006/0034679 A1 Feb. 16, 2006
Beabout US 5,511,309 Apr. 30, 1996

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THE REJECTIONS
Appellants seek review of the following rejections: 1
Claim 1 as rejected under 35 U.S.C. § 103(a) as unpatentable over
Harding, Cunha, and Beabout. Ans. 4-5.
Claims 3, 5, and 6 as rejected under 35 U.S.C. § 103(a) as
unpatentable over Harding and Cunha. Ans. 7.
Claims 3 and 6 as rejected under 35 U.S.C. § 102(a) as anticipated by
Cunha. Ans. 3.

ANALYSIS
Claim 1 as Unpatentable over Harding, Cunha, and Beabout
The Examiner finds that Harding teaches a method of impingement
cooling a turbine airfoil 18 with a large platform-to-airfoil fillet radius, the
method comprising: forming the airfoil fillet such that the fillet wall (flared
portions 24) is maintained at a minimum thickness; (b) inserting into the
airfoil an impingement tube (baffle 26) that follows the fillet contour to
platform transition (¶0020, lines 4-7); and (c) applying impingement air
through the impingement tube to the airfoil walls (¶0023). Ans. 5.
Paragraph [0023] of Harding teaches coolant entering baffle inlets 36,
flowing through holes 28, and impinging on the vane wall 22 to

1 Appellants seek to appeal claims 1, 3, 5, and 6, and are not seeking review
of the rejection of claims 2 and 7. See Supp App. Br. dated Dec 14, 2009;
Reply Br. 2. Therefore, we dismiss the appeal as to claims 2 and 7. See Ex
parte Ghuman, 88 USPQ2d 1478, 1480 (BPAI 2008) (precedential). We
note that § 1215.03 of the Manual of Patent Examining Procedure states that
a “withdrawal of the appeal as to some of the claims on appeal operates as
an authorization to cancel those claims from the application.”

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impingement cool the vane. The baffles are inserted as shown in Figure 2.
Id. The Examiner finds that Harding fails to teach using impinged air to
subsequently flow through airfoil fillet holes and provide film cooling to the
airfoil fillet, and coring the airfoil to form the fillet. Id.
The Examiner finds, however, that Cunha teaches a method of
impingement cooling a turbine airfoil comprising using impinged air to
subsequently flow through fillet holes and provide film cooling to the airfoil
fillet (¶0022). Ans. 5-6. The Examiner concludes that it would have been
obvious to one having ordinary skill in the art at the time the invention was
made to incorporate Cunha’s film cooling holes into Harding’s airfoil blade
to provide more efficient cooling of the blade. Ans. 6. The Examiner also
finds that Beabout teaches coring an airfoil to form cooling passages (col. 2,
ll. 1-15), and that a desired shape of an airfoil can be manufactured by
coring. Id. The Examiner reasons that if Beabout’s manufacturing method,
which includes coring, was used to manufacture the airfoil of Harding as
modified by Cunha, the claimed airfoil would be produced. Id. The
Examiner concludes that it would have been obvious to one having ordinary
skill in the art at the time the invention was made to form the airfoil of
Harding as modified by Cunha using the coring method taught by Beabout
for the purpose of making the airfoil with less machining. Id.
In the Response to Arguments section of the Answer, regarding
obviousness of combining Harding and Cunha, the Examiner states that
supplying film cooling holes with air from an upstream impingement
process is known as taught by Cunha and therefore adding film cooling
holes to Harding to cool the airfoil skin would have been obvious to one
having ordinary skill in the art. Ans. 11.
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Appellants argue that Harding does not disclose the claimed
impingement tube, but rather teaches a vane assembly 10 having no fillets
with a large platform-to-fillet radius. Reply Br. 5. To the extent that
Appellants are arguing that Harding does not teach the claimed large
platform-to-fillet radius, Appellants fail to explain the metes and bounds of a
large platform-to-fillet radius and why Harding’s teachings do not fall within
those metes and bounds.
Appellants also argue that Harding’s baffles 26 are dissimilar to the
impingement tubes of the claimed invention because they are fastened
together by a rigid fastener 48, and air enters the baffles from opposite
directions and leaves the impingement cavity 46 without film cooling a fillet
with a large radius. Reply Br. 6. To the extent that Appellants are arguing
that Harding does not teach the claimed large platform-to-fillet radius, as
explained above, Appellants fail to explain the metes and bounds of a large
platform-to-fillet radius and why Harding’s teachings do not fall within
those metes and bounds. To the extent that Appellants are arguing that
Harding’s baffles are not the claimed impingement tube because they are
fastened together by a rigid fastener 48 and air enters the baffles from
opposite directions, Appellants are arguing limitations that are not present in
the claims.
Appellants further argue that there is no reason to combine Harding
and Cunha because there is no rational basis to add the film cooling holes of
Cunha to the airfoil of Harding, as Harding does not have large radius fillets
and therefore does not need film cooling holes to provide cooling to an
airfoil fillet. Id. As stated above, Appellants fail to explain why Harding’s
teachings do not fall within the metes and bounds of a large platform-to-
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fillet radius. In addition, Appellants have not stated that the Examiner erred
in reasoning that it would have been obvious to one having ordinary skill in
the art at the time of the invention to incorporate Cunha’s film cooling holes
into Harding’s airfoil blade to provide “more efficient cooling of the blade”.
Regarding the Examiner’s reason for combining the teachings of
Beabout with Harding and Cunha, Appellants argue that Beabout discloses a
turbine stator vane whose structure is otherwise dissimilar to the structure of
Appellants’ airfoil, and the difference in structure renders it unobvious to
one skilled in art to adapt Beabout’s coring step to any of the other cited
references in order to obtain the applicant's invention. Id. Appellants fail to
explain how the difference in structure would render adaption of Beabout’s
coring step to the structure of Harding as modified by Cunha unobvious.
Appellants also argue that Beabout discloses coring to form serpentine
cooling passages, but not to form an airfoil fillet such that the fillet wall is
maintained at a minimum thickness, and that Beabout also does not disclose
coring a fillet with a large radius. Reply Br. 6, 7. The Examiner does not
allege that Beabout teaches a large radius fillet, but rather finds such
structure in Harding. Further, Appellants fail to explain the metes and
bounds of “minimum thickness,” and why the cited references do not
disclose a fillet wall that falls within those metes and bounds.
Appellants also argue that since fillets with large radiuses have not
been previously cored, despite that coring is generally known in the art,
there is strong evidence that coring a fillet with a large radius is not obvious.
Id. We do not find this argument persuasive. Appellants have not defined a
fillet with a “large radius,” have not supplied evidence that fillets with large
radiuses have not been cored, and have not explained how these facts show
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error in the Examiner’s reasoning that it would have been obvious to one
having ordinary skill in the art at the time the invention was made to form
the airfoil of Harding as modified by Cunha using the coring method taught
by Beabout for the purpose of making the airfoil with less machining.
We are not persuaded by Appellants’ arguments for the reasons set
forth above, and we therefore sustain the rejection of claim 1 as unpatentable
over Harding, Cunha, and Beabout.
Claims 3, 5, and 6 as Unpatentable over Harding and Cunha
As discussed above, the Examiner finds that Harding discloses a
system for impingement cooling a turbine airfoil with a large platform-to-
fillet radius, the system comprising the claimed airfoil, fillet, and inserted
impingement tube with holes for delivering impingement air to the fillet.
Ans. 7. The Examiner also finds that Harding teaches applying
impingement air through the impingement tube to the fillet walls. Ans. 8.
The Examiner admits that Harding does not teach a plurality of cooling
holes through the airfoil wall, but finds that Cunha discloses a plurality of
cooling holes through the airfoil wall, and concludes that it would have been
obvious to one having ordinary skill in the art at the time the invention was
made to incorporate Cunha’s film cooling holes into Harding’s airfoil blade
to more efficiently cool the airfoil blade. Ans. 7.
Appellants maintain the same arguments set forth above with respect
to the disclosure of Harding and the combination of Harding and Cunha,
additionally stating that “because of the complexities of airfoil cooling needs
and cooling air flow patterns, it would not be obvious to adapt the film
cooling holes of Cunha et al. to the vane of Harding et al.” Reply Br. 7-8.
Appellants do not provide, however, any description of such structural
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complexities or why they render it non-obvious to adapt Cunha’s film
cooling holes to Harding’s airfoil. We therefore are not persuaded by the
Examiner’s arguments and we sustain the rejection of claims 3, 5, and 6 as
unpatentable over Harding and Cunha.
Claims 3 and 6 as Anticipated by Cunha
Our affirmance of the rejection of claims 3 and 6 on one ground
specified by the Examiner, namely, under § 103(a) as unpatentable over
Harding and Cunha, constitutes a general affirmance of the decision of the
Examiner on those claims. 37 C.F.R. § 41.50(a). We do not address the
rejection of claims 3 and 6 under § 102(a) as anticipated by Cunha
separately, since the rejection under § 103(a) is dispositive as to all of the
claims involved in the rejection under § 102(a).
DECISION
We affirm the rejection of claim 1 under 35 U.S.C. § 103(a) as
unpatentable over Harding, Cunha, and Beabout.
We affirm the rejection of claims 3, 5, and 6 under 35 U.S.C. § 103(a)
as unpatentable over Harding and Cunha.
We do not reach the merits of the rejection of claims 3 and 6 under 35
U.S.C. § 102(a) as anticipated by Cunha.

AFFIRMED

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