PRATT & WHITNEY CANADA CORP.

Patent Trials and Appeals Board

Oct 6, 2020

2020000799 (P.T.A.B. Oct. 6, 2020)

UNITED STATES PATENT AND TRADEMARK OFFICE
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
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO.
14/287,125 05/26/2014 Mark Huzzard CUNNINGHAM 05002993-1704US
WHY/sa
2751
32292 7590 10/06/2020
NORTON ROSE FULBRIGHT CANADA LLP (PWC)
1, PLACE VILLE MARIE
SUITE 2500
MONTREAL, QUEBEC H3B 1R1
CANADA
EXAMINER
BURKE, THOMAS P
ART UNIT PAPER NUMBER
3741
NOTIFICATION DATE DELIVERY MODE
10/06/2020 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):
NRFCUSPTOMAIL@nortonrosefulbright.com
ipcanada@nortonrosefulbright.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte MARK HUZZARD CUNNINGHAM,
EDWARD PARKER VLASIC, and SAMI GIRGIS
Appeal 2020-000799
Application 14/287,125
Technology Center 3700
BEFORE STEFAN STAICOVICI, JEREMY M. PLENZLER, and
SUSAN L. C. MITCHELL, Administrative Patent Judges.
PLENZLER, Administrative Patent Judge.
DECISION ON APPEAL
STATEMENT OF THE CASE
Pursuant to 35 U.S.C. § 134(a), Appellant1 appeals from the
Examiner’s decision to reject claims 1, 3, 5–10, 12, and 13. We have
jurisdiction under 35 U.S.C. § 6(b).
We AFFIRM.

1 We use the word Appellant to refer to “applicant” as defined in 37 C.F.R.
§ 1.42(a). Appellant identifies the real party in interest as Pratt and Whitney
Canada Corp. Appeal Br. 2.
Appeal 2020-000799
Application 14/287,125

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CLAIMED SUBJECT MATTER
The claims are directed to a turbine exhaust case. Claim 1,
reproduced below, is illustrative of the claimed subject matter:
1. A turbine exhaust case (TEC) of a turbofan aeroengine
including a mixer for mixing exhaust gases with a bypass air
stream, the TEC comprising an annular hub and an annular
shroud with said mixer located at a downstream end of the
annular shroud, the mixer surrounding the annular hub to form
an annular exhaust gas duct positioned radially therebetween, the
mixer having an annular wavy configuration to form a plurality
of axially extending lobes of the mixer, the plurality of axially
extending lobes defining alternating crests and valleys extending
divergently to a downstream end of the mixer, a plurality of
deswirling struts circumferentially spaced apart with respect to a
central axis of the TEC and located within an axial length of the
mixer between an upstream end where exhaust gases enter the
mixer and the downstream end of the mixer where exhaust gases
are discharged from the mixer and mix with the bypass air
stream, leading edges of the deswirling struts being either axially
aligned with, or located downstream of, a start point where the
divergently extending crests and valleys start to extend away
from each other, each of the deswirling struts having a cambered
profile and extending radially across the annular exhaust gas duct
and interconnecting the mixer and the annular hub, the
deswirling struts cambered in a direction of an incoming swirling
flow of the exhaust gases such that a concave side of the
cambered profile faces the incoming swirling flow.
REFERENCES
The prior art relied upon by the Examiner is:
Name Reference Date
Ramm US 2010/0031631 A1 Feb. 11, 2010
Lefebvre US 2011/0036068 A1 Feb. 17, 2011
Hauswald DE 10 2010 044 483 A1 Mar. 8, 2012

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Application 14/287,125

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REJECTIONS
Claims 1, 3, 6–10, and 13 are rejected under 35 U.S.C. § 103 as being
unpatentable over Lefebvre and Ramm.
Claims 5 and 12 are rejected under 35 U.S.C. § 103 as being
unpatentable over Lefebvre, Ramm, and Hauswald.
OPINION
Appellant argues claims 1, 3, 6–10, and 13 as a group. Appeal Br. 7–
13.2 We select claim 1 as representative. Claims 3, 6–10, and 13 stand or
fall with claim 1. See 37 C.F.R. § 41.37(c)(1)(iv). Appellant also relies on
the arguments presented with respect to claim 1 for the patentability of
claims 5 and 12. Appeal Br. 13–14.
The Examiner finds that Lefebvre teaches each limitation of claim 1,
including “a plurality of deswirling struts (54),” but “does not teach the
details of the deswirling struts” (i.e. “the deswirling struts [being] cambered
in a direction of an incoming swirling flow of the exhaust gases such that a
concave side of the cambered profile faces the incoming swirling flow”).
Final Act. 3. The Examiner finds that “Ramm teaches . . . deswirling struts
(7) [that] have a cambered profile . . . in a direction of an incoming swirling
flow of the exhaust gases . . . such that a concave side of the cambered
profile faces the incoming swirling flow.” Id. Appellant does not dispute
these findings.
The Examiner reasons that “[i]t would have been obvious . . . to
modify Lefebvre to include the cambered profile of the struts as taught by

2 For simplicity, we cite only to Appellant’s arguments in the Appeal Brief,
as the contentions presented in the Reply Brief are reiterations of those from
the Appeal Brief.
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Application 14/287,125

4
Ramm in order to deflect the hot gas in the axial direction so that the hot gas
is as non-rotational as possible (Paragraph 0018).” Final Act. 4. Appellant
responds that: (1) Lefebvre teaches away from the proposed combination
(id. at 7–10); (2) the proposed combination would not have yielded
predictable results (id. at 10–13); and (3) the proposed combination is based
on conclusory statements (id. at 13).
Appellant contends that “the purpose of the struts of Lefebvre and
those of Ramm are very different” because “Lefebvre aims at minimizing
the impact the struts have on the flow circulating therearound whereas
Ramm aims at imparting a force on said flow.” Appeal Br. 8. Specifically,
Appellant contends that “the struts of Lefebvre modified as suggested by the
Office in view of Ramm will create more obstruction on the incoming flow
and will impart a force on said incoming flow,” which “Lefebvre[ teaches]
would unfavorably increase turbulence and back pressure.” Id. at 9.
Appellant is correct that Lefebvre teaches its “struts 54 hav[ing] a
generally aerodynamic profile for limiting any obstruction of the high
velocity flows passing through the main gas path 26.” Lefebvre ¶ 25. As
the Examiner notes, however, Lefebvre explains that its embodiments are
merely exemplary, and various aerodynamic strut profiles can be used.
Ans. 4; Lefebvre ¶ 25 (“The specific mixer strut aerodynamic profile shown
in FIG. 7 is exemplary only.” (emphasis added)). Appellant responds that
“even if a person skilled in the art were to use a different profile . . . , this
person would never opt for a profile that would display a greater transversal
width” or “for a profile that would impart a force on the incoming flow.”
Appeal Br. 9. Appellant’s contention is not persuasive.
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We fail to see a teaching in Lefebvre that discourages the use of the
proposed modification. See In re Fulton, 391 F.3d 1195, 1201 (Fed. Cir.
2004) (A teaching away requires “criticiz[ing], discredit[ing], or otherwise
discourag[ing] the solution claimed.”). Rather than being discouraged from
the proposed modification, one skilled in the art would have appreciated the
trade-offs between mixing and obstructions to flow, as expressly taught by
Ramm. See, e.g., Ramm ¶ 4 (“As the degree of mixing increases, the flow
losses also increase as a rule. A good mixer therefore represents a
compromise between these two effects.”).
Appellant’s contentions regarding the alleged lack of predictable
results are similarly unpersuasive. Appellant contends that “there are many
differences between the mixers of Lefebvre and of Ramm” and “stresses
here that designing a mixer is a complicated and cumbersome task.” Appeal
Br. 11. Appellant’s contentions, however, amount to no more than
unsupported allegations, which do not apprise us of error. Appellant
references a declaration by one of the named inventors, Mark Huzzard
Cunningham, submitted in a related application (15/673,047) (“the
Cunningham Declaration”). Id. at 12. The Cunningham Declaration was
filed in the related proceeding after this appeal, and is not in the record in
this proceeding. We do not consider the Cunningham Declaration in this
appeal. See 37 C.F.R. § 41.33(d)(2) (explaining that evidence filed after
appeal will not be admitted, except for certain circumstances).3
Moreover, even if that declaration was properly before us, it would
not be persuasive of Examiner error because of the internal inconsistencies

3 As noted above, the Cunningham Declaration was never filed in this
proceeding.
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therein and the lack of any evidence supporting the statements therein relied
on by Appellant. For example, Dr. Cunningham summarily concludes,
without supporting evidence or meaningful explanation, that “it is clear to
me that the struts 54 [in Lefebvre] are not configured to remove a
circumferential component of the flow exiting the turbine section of the gas
turbine engine” and “[t]hey are simply not long enough in term of their
chord length to exert a force on the surrounding flow that would act to
change a circumferential component of the flow circulating around them.”
Cunningham Declaration ¶ 7. Dr. Cunningham similarly concludes that he
is “positive that if the struts 54 were able to change a circumferential
component of the flow circulating around them––by changing an angle of
attack or with a cambered aerodynamic profile for instance––they would
impart turbulence to the flow around them and, hence, they would clearly
generate vibrations.” Id. ¶ 8. Dr. Cunningham then testifies that “due to the
complexity of the flow circulating through those mixers, their real-life
performances are very difficult to predict, even with currant tools such as
computational fluid dynamics.” Id. ¶ 13. Accordingly, in view of these
internal inconsistencies and lack of supporting evidence, Dr. Cunningham’s
testimony would receive little weight, even if properly before us.
Appellant’s contention that the rejection is based on conclusory
statements is baseless. As noted above, the Examiner cites Ramm’s express
disclosure to support the reason for the proposed modification to Lefebvre’s
teachings. Final Act. 4 (citing Ramm ¶ 18). Indeed, consistent with the
Examiner’s explanation, Ramm expressly states that “[t]he hot gas exiting
from the rearmost guide blade ring 4 with rotation . . . is deflected in the
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axial direction by the profiled and curved . . . struts 7 of the guide ring and is
therefore as non-rotational as possible.” Ramm ¶ 18.
For at least the reasons set forth above, we are not apprised of
Examiner error.
CONCLUSION
The Examiner’s rejections are affirmed.
DECISION SUMMARY
In summary:
Claims
Rejected
35
U.S.C.
§
Reference(s)/Basis Affirmed Reversed
1, 3, 6–10, 13 103 Lefebvre, Ramm 1, 3, 6–10,
13

5, 12 103 Lefebvre, Ramm,
Hauswald
5, 12
Overall
Outcome
1, 3, 5–10,
12, 13

TIME PERIOD FOR RESPONSE
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a). See 37 C.F.R.
§ 1.136(a)(1)(iv).
AFFIRMED