PRATT & WHITNEY CANADA CORP.

Patent Trials and Appeals Board

Nov 2, 2020

2020001783 (P.T.A.B. Nov. 2, 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.
15/673,047 08/09/2017 Remo MARINI 05002993-1704US-3 8980
32292 7590 11/02/2020
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
11/02/2020 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 REMO MARINI and MARK HUZZARD CUNNINGHAM
Appeal 2020-001783
Application 15/673,047
Technology Center 3700
Before STEFAN STAICOVICI, BRETT C. MARTIN, and
JEREMY M. PLENZLER, 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 18, 20–29, and 31–37.2 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.
2 Claims 1–17, 19, and 30 are cancelled. Final Act. 2.
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Application 15/673,047

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CLAIMED SUBJECT MATTER
The claims are directed to a turbine exhaust case. Claim 18,
reproduced below, is illustrative of the claimed subject matter:
18. A turbine exhaust case (TEC) for a turbofan aero engine,
comprising a hub being annular, an annular shroud, a mixer
surrounding the hub, and deswirling struts extending from the
hub to the mixer, the deswirling struts configured in use to
deswirl a flow of exhaust gases circulating near the hub, the
mixer including lobes extending axially from a downstream
side of the annular shroud to trailing edges, the lobes defining
alternating diverging crests and valleys, the deswirling struts
connected to valleys of the mixer, wherein at least one of the
valleys is free of direct connection with the deswirling struts,
wherein the deswirling struts are entirely located within an axial
length of the mixer, the axial length starting at a starting point
where the divergently extending crests and valleys start to
extend away from each other.
REFERENCES
The prior art relied upon by the Examiner is:
Name Reference Date
Neal US 4,117,671 Oct. 3, 1978
Siefker US 6,606,854 B1 Aug. 19, 2003
Ramm US 2010/0031631 A1 Feb. 11, 2010
Lefebvre US 2011/0036068 A1 Feb. 17, 2011
REJECTIONS
Claims 18, 20–29, and 31–37 are rejected under 35 U.S.C. § 103 as
being unpatentable over Lefebvre and Ramm.
Claims 18 and 29 are rejected under 35 U.S.C. § 103 as being
unpatentable over Neal, Ramm, and Siefker or Lefebvre.
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Application 15/673,047

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OPINION
Related Appeal
In its Appeal Brief, Appellant notes that “[t]he instant application is a
continuation of U.S. application No. 14/521,888 filed on October 23, 2014,
which is a continuation-in-part of U.S. application No. 14/287,125 filed May
26, 2014, which is currently under appeal.” Appeal Br. 2. The appeal
referenced by Appellant is Appeal No. 2020-000799 (“the ’799 Appeal”),
which was decided on October 6, 2020, resulting in an affirmance of the
Examiner’s rejections.
Lefebvre/Ramm
Appellant argues claims 18, 20–29, and 31–37 as a group. Appeal Br.
5–9.3 We select claim 18 as representative. Claims 20–29, and 31–37 stand
or fall with claim 18. See 37 C.F.R. § 41.37(c)(1)(iv).
The Examiner finds that Lefebvre teaches each limitation of claim 18,
including “deswirling struts (54),” but “does not teach that the deswirling
struts are configured to in use to deswirl a flow of exhaust gases circulating
near the hub.” Final Act. 3. The Examiner finds that “Ramm teaches
(Figures 1-4) deswirling struts (7) configured to in use to deswirl (due to the
shape of the struts) a flow of exhaust gases circulating near the hub
(Paragraph 0018).” Id. Appellant does not dispute these findings.
The Examiner reasons that “[i]t would have been obvious to one
having ordinary skill in the art before the effective filing date of the claimed
invention to modify Lefebvre to include the strut shape as taught by Ramm

3 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 15/673,047

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in order to deflect the hot gas exiting the turbine such that it is as non-
rotational as possible (Paragraph 0018).” Final Act. 3. Appellant responds
that: (1) the Examiner’s proposed combination destroys Lefebvre (Appeal
Br. 5–7); and (2) the proposed combination would not have yielded
predictable results (id. at 7–9). Those contentions are similar to those found
unpersuasive in the ’799 Appeal.
Appellant contends that “[t]he purpose of the struts of Lefebvre is
very different than the purpose of the struts of Ramm” because “[t]he struts
of Lefebvre have a purely structural function and are designed to minimize
their impact on the flow circulating therearound whereas the struts of Ramm
are designed to impart a force on the flow.” Appeal Br. 6. Specifically,
Appellant contends that
modifying Lefebvre in view of Ramm destroys Lefebvre on two
fronts as such a modification will: 1. increase the transversal
width of the struts of Lefebvre, which will translate in an
increase in back pressure and turbulence; and 2. impart a force
on the incoming flow, which will increase obstruction on the
incoming flow caused by the struts.
Id. at 7.
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. 4–5; Lefebvre ¶ 25 (“The specific mixer strut aerodynamic profile
shown in FIG. 7 is exemplary only.”). Rather than being discouraged from
the proposed modification, one skilled in the art would have appreciated the
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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 “the mixers of
Lefebvre and Ramm are quite different” (Appeal Br. 8) and “designing a
mixer is a complicated task” (id. at 9). 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, which was also addressed in the ’799 Appeal.
Id. at 8. That declaration is not persuasive of Examiner error because of the
internal inconsistencies 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.
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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 current tools such as computational fluid
dynamics.” Id. ¶ 13. Accordingly, in view of these internal inconsistencies
and lack of supporting evidence, Dr. Cunningham’s testimony does not
apprise us of error in the Examiner’s rejection.
For at least the reasons set forth above, we are not apprised of
Examiner error.
Neal/Ramm/Siefker/Lefebvre
The Examiner additionally rejects claims 18 and 29 based on
modifications to Neal’s turbine exhaust case. Final Act. 12–15. Appellant
argues claims 18 and 29 as a group when responding to this rejection.
Appeal Br. 9–13. We select claim 18 as representative. Claim 29 stands of
falls with claim 18.
Appellant responds with contentions similar to those discussed above
that are unpersuasive for similar reasons. See Appeal Br. 9–13. Appellant’s
contentions that “the results of the combination are not predictable” (id. at
10–12) are unpersuasive for the reasons set forth above. Appellant’s
contention that “the combination destroys Neal” (id. at 12) are also
unpersuasive, as Appellant, again, contends that because the references take
a “different approach” one skilled in the art would not have made the
proposed combination. As previously explained, 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.”).
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We also are not apprised of error in this additional rejection of claims
18 and 29.
CONCLUSION
The Examiner’s rejections are affirmed.
DECISION SUMMARY
In summary:
Claims
Rejected
35 U.S.C.
§
Reference(s)/Basis Affirmed Reversed
18, 20–29,
31–37
103 Lefebvre, Neal 18, 20–29,
31–37

18, 29 103 Neal, Ramm,
Siefker, Lefebvre
18, 29
Overall
Outcome
18, 20–29,
31–37

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