Ex Parte Quach et al

Patent Trials and Appeals Board

Apr 17, 2019

14632485 - (D) (P.T.A.B. Apr. 17, 2019)

UNITED STA TES p A TENT AND TRADEMARK OFFICE
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR
14/632,485 02/26/2015 San Quach
54549 7590 04/19/2019
CARLSON, GASKEY & OLDS/PRATT & WHITNEY
400 West Maple Road
Suite 350
Birmingham, MI 48009
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.
67097-3164PUS1;79728US01 6267
EXAMINER
PRUITT, JUSTIN A
ART UNIT PAPER NUMBER
3745
NOTIFICATION DATE DELIVERY MODE
04/19/2019 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):
ptodocket@cgolaw.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte SAN QUACH, RYAN ALAN WAITE, CHRISTOPHER KING,
and STEVEN BRUCE GAUTSCH!
Appeal2018-006219
Application 14/632,485 1
Technology Center 3700
Before STEFAN STAICOVICI, JEREMY M. PLENZLER, and
LISA M. GUIJT, Administrative Patent Judges.
STAICOVICI, Administrative Patent Judge.
DECISION ON APPEAL
STATEMENT OF THE CASE-
Appellants appeal under 35 U.S.C. § 134(a) from the Examiner's
decision in the Final Office Action ( dated Sept. 7, 2017, hereinafter "Final
Act.") rejecting claims 1--4, 6, and 9-22. 2 We have jurisdiction over this
appeal under 35 U.S.C. § 6(b ).
1 United Technologies Corporation is the applicant, and identified as the real
party in interest in Appellants' Appeal Brief (filed Jan. 24, 2018, hereinafter
"Appeal Br."). Appeal Br. 1.
2 Claims 5, 7, and 8 are canceled. Final Act. 2.
Appeal2018-006219
Application 14/632,485
We REVERSE.
SUMMARY OF DECISION
INVENTION
Appellants' invention is directed to a cooling arrangement for an
airfoil of a gas turbine engine. Spec. para. 2.
Claims 1 and 16 are independent. Claim 1 is illustrative of the
claimed invention and reads as follows:
1. An airfoil for a gas turbine engine comprising:
an airfoil including spaced apart pressure and suction
side walls joined at leading and trailing edges to provide an
exterior airfoil surface extending in a radial direction from a
platform to a tip;
a cavity provided between the pressure and suction side
walls near the trailing edge, the cavity includes an interior
region bounded by a first exit region at the trailing edge and a
second exit region at the tip, the first and second exit regions
arranged at angle relative to one another, the first and second
exit regions are respectively in low and high pressure regions
relative to one another; and
first and second pedestal groups respectively arranged at
the first and second exit regions, the second pedestal group has
first and second pedestals each terminating in an end, the ends
of the second pedestals extend beyond the ends of first
pedestals, the second pedestals are longer than the first
pedestals and in that the second pedestal group is recessed from
the tip.
REJECTIONS
I. The Examiner rejects claims 1--4, 6, and 12-21 under 35 U.S.C.
§ 103 as being unpatentable over Liang (US 2005/0281671 Al,
pub. Dec. 22, 2005), Lewis et al. (US 2014/0044555 Al, pub.
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Application 14/632,485
Feb. 13, 2014, hereinafter "Lewis"), and Morris et al. (US
2013/0064639 Al, pub. Mar. 14, 2013, hereinafter "Morris").
II. The Examiner rejects claims 9-11 and 22 under 35 U.S.C. §
103 as being unpatentable over Liang, Lewis, Morris, and
Levine et al. (US 2013/0280080 Al, pub. Oct. 24, 2013,
hereinafter "Levine").
ANALYSIS
Rejection I
The Examiner finds that Liang discloses a gas turbine airfoil 10
including, inter alia, an exterior surface that extends from a platform (root)
20 to a tip 22 and defined by pressure sidewall 12, suction sidewall 14,
leading edge 16, and trailing edge 18. Final Act. 6 (citing Liang, Fig. IA).
The Examiner further finds that Liang discloses a cooling cavity passage 25
located between pressure sidewall 12 and suction sidewall 14 near trailing
edge 18, wherein the cavity includes a first exit region at the trailing edge 18
and a second exit region at tip 22 defined by dispersion cavity 42 and open
flow channel 52. Id. (citing Liang, Fig. IB). Furthermore, the Examiner
finds that Liang discloses the claimed first and second pedestal groups and
provides an annotated Figure 2B of Liang, as shown below, to illustrate their
respective locations:
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Application 14/632,485
The Examiner's annotated Figure 2B of Liang illustrates the claimed first
pedestal group located at trailing edge 18, and the second pedestal group
located at tip 22 and formed by ribs 56, 58. See id. at 7.
However, the Examiner finds that Liang does not disclose that "the
second pedestal group has first and second pedestals each terminating in an
end, the ends of the second pedestals extend[ing] beyond the ends of [the]
first pedestals" and that "the second pedestal group is recessed from the tip."
Id. at 7, 8. Nonetheless, the Examiner finds that Lewis discloses first and
second pedestals 191, 193, wherein second pedestals 193 are longer than
first pedestals 191 and the ends of second pedestals 193 extend beyond the
ends of first pedestals 191. Id. at 8 ( citing Lewis, para. 52, Fig. 7). The
Examiner further finds that Morris discloses a turbine blade having "a
pressure sidewall recessed from the trailing edge of the suction wall (214)
and ribs ( dividers 480) which terminate upstream of the pressure side trailing
edge (312)." Id.
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Thus, the Examiner first determines that it would have been obvious
to a skilled artisan "to have modified the airfoil as taught by Liang with the
above aforementioned pedestals as taught by Lewis for the purpose of
cooling the trailing edge." Id. (citing Lewis, para. 1). The Examiner further
concludes that
It would have been obvious to one of ordinary skill in the art at
the time of filing to have modified the second pedestal group as
taught by the combined teachings of Liang as modified by
Lewis by recessing the pedestals as taught by Morris for the
purpose of reducing or eliminating flow separation on the
interior surface of the suction side wall.
Id. at 8-9 ( citing Morris, para. 36).
Appellants argue that recessing ribs 56, 58 of Liang, as modified by
Lewis, according to Morris, "would undermine the purpose of fully
extending ribs in Liang." Appeal Br. 4--5. According to Appellants, fully
extending ribs 56, 58 protects dispersion flow 44 from mixing with high
combustion fluid flow 28. Id. at 5 (citing Liang, para. 12). Appellants
further contend that because Liang discloses a "desirability of structural
integrity in the trailing edge comer 24," recessing ribs 56, 58 according to
the Examiner's rejection, "would be detrimental to structural rigidity," and,
thus, "[a] skilled worker would not modify Liang to weaken the comer 24 by
making the ribs 56, 58 smaller." Id. at 6.
The Examiner responds that Liang does not disclose that it is critical
to extend ribs 56, 58 fully along the length of the flow channel "in order to
sufficiently protect dispersed flow 44 from being disturbed by the hot
combustion gasses 28." Examiner Answer (dated Apr. 5, 2018, hereinafter
"Ans.") 3. According to the Examiner,
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Liang does not teach nor suggest that the ribs must fully extend
to the trailing edge as the Appellant asserts; nor does Liang
disclose or suggest that the maximum protection possible of
dispersed flow 44 is required but rather sufficiently protected
(Para. 0012); nor does Liang disclose or suggest that the
maximum structural rigidity possible is required but rather a
desired level of structural rigidity (Para. 0013).
Id. Furthermore, the Examiner points to Liang's statement that rib
geometry, such as rib length, "may be selected to achieve a desired rigidity
. . . and to control a flow of the dispersed flow 44" "directly contradicts any
argument that the ribs must fully extend to the trailing edge." Id. at 5 (citing
Liang, para. 13).
It is well established that if the proposed modification would render
the prior art invention being modified unsatisfactory for its intended
purpose, then there is no suggestion or motivation to make the proposed
modification. In re Gordon, 733 F.2d 900, 902 (Fed. Cir. 1984). Here,
Liang discloses a cooling configuration for trailing edge comer 24 including,
inter alia, providing dispersion cavity 42 for dispersing metering flow 40
and cooling internal surface portion 50 of cavity 42 and open flow channel
52 for conducting dispersed flow 44 to periphery 54 of the airfoil. Liang,
paras. 11, 12, Fig. 2B. Liang further discloses that spaced apart ribs 56, 58
define both dispersion cavity 42 and open flow channel 52, and together
with suction sidewall 14 "sufficiently" protect dispersed flow 44 from
mixing with hot combustion fluid flow 28 flowing around an exterior of
airfoil 10 in order "to cool the airfoil in the vicinity of the flow channel 52."
Id., para. 12 (emphasis omitted), Fig. 2B. Hence, we agree with Appellants
that extending Liang's ribs 56, 58 to periphery 54 of airfoil 10 is "desirable
to protect the dispersion flow 44 from the dispersion cavity 42 from mixing
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with the high combustion fluid flow 28" flowing around an exterior of airfoil
10. Appeal Br. 5 (emphasis added).
We appreciate the Examiner's position that Liang does not explicitly
disclose that ribs 56, 58 must fully extend to trailing edge comer 24 or that
maximum protection of dispersed flow 44 is required. However, we must
attribute skill to the hypothetical person described in 35 U.S.C. § 103(a). In
re Sovish, 769 F.2d 738, 742 (Fed. Cir. 1985). Here, because Liang
discloses that open flow channel 52 receives dispersed flow 44 and conducts
it to periphery 54 of airfoil 10, a skilled artisan would readily recognize that
in order to achieve "sufficient" protection of dispersed flow 44 spaced apart
ribs 56, 58 of Liang must extend to periphery 54 of airfoil 10. See Liang,
para. 12. In other words, Liang discloses that adequate cooling is provided
to trailing edge comer 24 of airfoil 10 when dispersed flow 44 is conducted
to periphery 54 via open air flow channel 52 defined by ribs 56, 58 and
suction sidewall 14. As such, we agree with Appellants that recessing
spaced apart ribs 56, 58, in the airfoil of Liang, as modified by Lewis, from
its periphery 54, as taught by Morris, is "counterproductive" to protecting
dispersed flow 44 from mixing with hot combustion fluid flow 28 flowing
around an exterior of airfoil 10. See Reply Brief (filed May 16, 2018,
hereinafter "Reply Br.") 1.
Further, we do not agree with the Examiner's position that because
Liang discloses open flow channel 52 as open on a pressure side of airfoil
10, this means that it is not critical for spaced apart ribs 56, 58 to extend to
periphery 54 of airfoil 10, as such a position requires speculation on the
Examiner's part. See Ans. 3. Liang specifically discloses a trailing edge
comer configuration that balances improved cooling characteristics with
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aerodynamic efficiency and "sufficient strength." Liang, para. 10.
Recessing spaced apart ribs 56, 58, in the airfoil of Liang, as modified by
Lewis, from its periphery 54, as taught by Morris, would be damaging to this
balance because it would further reduce the amount of material used in
trailing edge comer 24, and, as Appellants correctly contend, it "would be
detrimental to structural rigidity." Appeal Br. 6; see also Liang, para. 12.
Such a modification would further be detrimental because it would affect the
mixing of dispersed flow 44 with hot combustion fluid flow 28 flowing
around an exterior of airfoil 10. The Examiner has not adequately explained
how recessing spaced apart ribs 56, 58, in the airfoil of Liang, as modified
by Lewis, from its periphery 54, as taught by Morris, would maintain
Liang's balance between improved cooling characteristics, aerodynamic
efficiency, and "sufficient strength."
Furthermore, the reasoning provided by the Examiner to modify
Liang' s airfoil-for the purpose of reducing or eliminating flow separation
on the interior surface of the suction side wall----does not support the
conclusion of obviousness because the Examiner has not shown the
relevance of that rationale in the context of the trailing edge corner of
Liang's airfoil. See Final Act. 8-9. The Examiner has not established that
recessing spaced apart ribs 56, 58 from the periphery 54 in the airfoil of
Liang, as modified by Lewis and Morris, results in "the reduction or
elimination of flow separation [that] would also protect the trailing edge
corner of Liang." Ans. 4 (emphasis added). We, thus, agree with
Appellants "the recessed ribs of Morris do not relate to the structural rigidity
and flow protection problem of Liang, which relates to the tip of the airfoil,
not the trailing edge." Reply Br. 1-2. Accordingly, the Examiner has failed
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to establish that one of ordinary skill in the art would have had reason to
modify Liang' s airfoil in the manner proposed.
Lastly, we do not agree with the Examiner that when referring to the
"length" of rib 56, 58, Liang refers to the dimension of the rib in the
direction of flow. See Ans. 5. Rather, we agree with Appellants that "[t]he
'length' of the ribs discussed in ... Liang ... relates to the length of the rib
extending interiorly into the airfoil rather than" in the flow direction of
dispersed flow 44. Reply Br. 1; see also Liang, Fig. 2B (note flow direction
of dispersed flow 44 as illustrated by an arrow). Such an interpretation is
consistent with Liang's description of flow channel 52 as an open channel
defined by ribs 56, 58 and suction sidewall 14 that conducts dispersed flow
44 to periphery 54 of airfoil 10. See Liang, para. 12. In other words,
Liang's ribs 56, 58 include a first dimension along the flow direction of
dispersed flow 44 and a second dimension extending from suction sidewall
14 towards pressure sidewall 12. As Liang discloses flow channel 52 as an
open channel, it is the second dimension extending from suction sidewall 14
towards pressure sidewall 12 that Liang discloses "may be selected to
achieve a desired rigidity of the trailing edge comer 24 ... and to control a
flow of the dispersed flow 44." Liang, para. 13 (emphasis omitted).
In conclusion, for the foregoing reasons, the Examiner's modification
of recessing spaced apart ribs 56, 58, in the airfoil of Liang, as modified by
Lewis, from its periphery 54, as taught by Morris, would render Liang's
cooling configuration of trailing edge comer 24 of airfoil 10 unsatisfactory
for its intended purpose.
Accordingly, we do not sustain the rejection under 35 U.S.C. § 103 of
claims 1--4, 6, and 12-21 as unpatentable over Liang, Lewis, and Morris.
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Rejection II
The Examiner's use of the Levine disclosure does not remedy the
deficiency of the Examiner's combination of Liang, Lewis, and Morris as
discussed supra. See Final Act. 18-21. Therefore, for the reasons discussed
above, we also do not sustain the rejection of claims 9-11 and 22 over the
combined teachings of Liang, Lewis, Morris, and Levine.
SUMMARY
The Examiner's decision to reject claims 1--4, 6, and 9-22 under 35
U.S.C. § 103 is reversed.
REVERSED
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