PRATT & WHITNEY CANADA CORP.

Patent Trials and Appeals Board

May 26, 2021

2020006323 (P.T.A.B. May. 26, 2021)

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.
15/210,213 07/14/2016 Eduardo HAWIE 05002993-1477US-1 1161
32292 7590 05/26/2021
NORTON ROSE FULBRIGHT CANADA LLP (PWC)
1, PLACE VILLE MARIE
SUITE 2500
MONTREAL, QUEBEC H3B 1R1
CANADA
EXAMINER
GOYAL, ARUN
ART UNIT PAPER NUMBER
3741
NOTIFICATION DATE DELIVERY MODE
05/26/2021 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 EDUARDO HAWIE and NIGEL DAVENPORT

Appeal 2020-006323
Application 15/210,213
Technology Center 3700
____________

Before MICHAEL L. HOELTER, WILLIAM A. CAPP, and
JEREMY M. PLENZLER, Administrative Patent Judges.

HOELTER, 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 1–20, which constitute all the claims
pending in this application. See Appeal Br. 2. We have jurisdiction under
35 U.S.C. § 6(b).
We AFFIRM the Examiner’s rejections of these claims.

1 We use the word “Appellant” to refer to “applicant” as defined in
37 C.F.R. § 1.42. Appellant identifies the real party in interest as “Pratt &
Whitney Canada Corp.” Appeal Br. 2.
Appeal 2020-006323
Application 15/210,213

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CLAIMED SUBJECT MATTER
The disclosed subject matter “relates generally to gas turbine engines
and, more particularly, to two-stage combustors.” Spec. 1:4-5. Apparatus
claims 1 and 17 are independent. Claim 1 is illustrative of the claims on
appeal and is reproduced below.
1. A combustor for a gas turbine engine, the engine having
a central axis, the combustor comprising:
an inner annular liner wall having an axially forward end
generally radially oriented, the inner annular liner wall curving
into an axial orientation as it extends in an aft direction to an
axially aft end of the inner liner;
an outer annular liner wall having an axially forward end
generally radially oriented, the outer annular liner wall curving
into an axial orientation as it extends in an aft direction to an
axially aft end of the outer liner, with the inner annular liner
wall and the outer annular liner wall spaced apart and
cooperating to form a combustion chamber of the combustor;
a first dome wall extending generally axially adjacent to
the inner annular liner wall and circumscribing the forward end
on the inner liner, the first dome wall having a circumferential
array of first fuel injection bores radially extending through the
first dome wall;
a second dome wall extending generally axially adjacent
to the outer annular liner wall and circumscribing the forward
end of the outer liner, the second dome wall having a
circumferential array of second fuel injection bores radially
extending through the second dome wall; and
an intermediate wall extending between the first dome
wall and the second dome wall and being an intermediate single
annular wall, the intermediate wall having a portion projecting
from the first dome wall and the second dome wall to from2 a
step between the outer surfaces of the first dome wall and the
second dome wall, a first combustion stage defined at least by

2 The Examiner understands, and Appellant concurs, that this should be
“form,” not “from.” See Interview Summary dated November 1, 2019.
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Application 15/210,213

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the inner annular liner wall forward end, the first dome wall and
the intermediate wall, a second combustion stage defined at
least by the outer liner wall forward end, the second dome wall
and the intermediate wall, the first combustion stage
communicating with the first fuel injection bores, the second
combustion stage communicating with the second fuel injection
bores.
EVIDENCE
Name Reference Date
Markowski US 3,811,277 May 21, 1974
Stenger et al. (“Stenger”) US 5,421,158 June 6, 1995
Alary et al. (“Alary”) US 5,592,820 Jan. 14, 1997
Brehm US 6,058,710 May 9, 2000
Dailey et al. (“Dailey”) US 6,334,297 B1 Jan. 1, 2002
Mancini et al. (“Mancini”) US 7,716,931 B2 May 18, 2010
Zupanc et al. (“Zupanc”) US 7,966,821 B2 June 28, 2011
REJECTIONS
Claims 1–16 are rejected under 35 U.S.C. § 112, second paragraph, as
being indefinite for failing to particularly point out and distinctly claim the
subject matter which applicant regards as the invention.
Claims 1, 2, 5–8, 10–17, 19, and 20 are rejected under 35 U.S.C.
§ 103(a) as unpatentable over Mancini, Brehm, Dailey, and Stenger.
Claims 3 and 4 are rejected under 35 U.S.C. § 103(a) as unpatentable
over Mancini, Brehm, Dailey, Stenger, and Markowski.
Claim 9 is rejected under 35 U.S.C. § 103(a) as unpatentable over
Mancini, Brehm, Dailey, Stenger, and Zupanc.
Claim 18 is rejected under 35 U.S.C. § 103(a) as unpatentable over
Mancini, Brehm, Dailey, Stenger, and Alary.
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ANALYSIS
The rejection of claims 1–16
as being indefinite
The Examiner identifies specific language in independent claim 1 for
which there is “insufficient antecedent basis.” Final Act. 2. The Examiner
also addresses a claim 1 limitation in which the recited “intermediate wall”
forms a step, explaining that “the ‘intermediate wall’ works as a riser of the
steps and the two dome walls ‘form’ the two steps.” Final Act. 2. Appellant
concurs in this analysis and sought to amend claim 1 accordingly, but “the
Examiner did not enter these amendments.” Appeal Br. 7. Thus, Appellant
states, “[a] future amendment will hence be made to overcome this rejection
at the next available opportunity to do so.” Appeal Br. 7.
In light of Appellant’s concurrence in the matter, and a lack of any
explanation from Appellant as to why or how the Examiner might be
mistaken, we summarily sustain the Examiner’s rejection of independent
claim 1, and dependent claims 2–16, as being indefinite.
The rejection of claims 1, 2, 5–8, 10–17, 19, and 20
as unpatentable over Mancini, Brehm, Dailey, and Stenger
Appellant argues these claims together. See Appeal Br. 7–19. We
select claim 1 for review, with the remaining claims standing or falling with
claim 1. See 37 C.F.R. § 41.37(c)(1)(iv) (2019).
The Examiner primarily relies on the teachings of Mancini for
disclosing the limitations of claim 1, but also acknowledges that Mancini
does not teach a second dome wall with second fuel injection bores
therethrough. Final Act. 3. In effect, it can be said that Mancini teaches a
single-stage compressor, not the two-stage compressor recited. See Appeal
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Br. 8. The Examiner relies on the teachings of Brehm for disclosing the
lacking second dome wall and recited second fuel injection bores (i.e., a
two-stage compressor). See Final Act. 4; Appeal Br. 9. The Examiner’s
reason for modifying “Mancini’s combustor with two stage design (double
dome design) of Brehm” is “in order to reduce emissions.” Final Act. 5.
The Examiner supports this reason by citing to Stenger which states,
“[e]fforts to reduce emissions in gas turbine engines have brought about the
use of staged combustion techniques.” Stenger 1:18–20.
However, the above combination of Mancini and Brehm still lacks the
disclosure of an “intermediate wall” separating the stages. See Final Act. 5;
Appeal Br. 9. The Examiner relies on Dailey’s teaching of an intermediate
wall 55 which separates the two stages prior to when their respective
combustion products are combined downstream. See Final Act. 5; Appeal
Br. 10 (both referencing an annotation of Figure 2 of Dailey). Dailey also
discloses a two-stage combustor, and the Examiner reasons that it would
have been obvious “to include an intermediate wall that extends between the
first and second combustion stages . . . in order that different air fuel ratio’s
and combustion conditions can be provided in both regions.” Final Act. 5–6
(referencing Dailey 4:25–45). Indeed, this section of Dailey states that the
separation provided by wall 55 allows “different air fuel ratio’s and
combustion conditions” to occur in each stage because controlling the
air/fuel ratio affects “the stability, efficiency and pollution products
produced in each region and from the combustor as a whole.” Dailey 4:26–
35; see also Ans. 5.
Appellant provides an overview of the Examiner’s analysis above and
also annotates various figures from these references in this discussion. See
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Appeal Br. 7–11. However, when addressing the initial combination of
Mancini and Brehm, Appellant contends that the orientation of the combined
fuel injectors, and hence their bores, is incorrect. See Appeal Br. 12.
Appellant contends, “[t]he alleged second dome wall (as per the Office’s
annotated Fig. 3 of Brehm) is radial” and as such, “the injectors 4 cannot
extend radially through the alleged second dome wall of Brehm.”3 Appeal
Br. 12. Instead, as per Appellant, the bores would extend axially through the
second dome wall.
To be clear, the Examiner is modifying Mancini “in view of Brehm.”
Final Act. 3. The primary reference to Mancini discloses the bores having
the proper orientation. See Mancini Fig. 2. In the Examiner’s Answer, the
Examiner annotates Mancini’s Figure 2 to show the combustor having a
second stage as taught by Brehm, wherein the bores are orientated radially,
as recited. See Ans. 4. The Examiner further asserts “that the orientation of
Brehm’s combustor is relative” and, upon combination with that of Mancini,
the combination would teach “both stages to include axially extending dome
walls and radially extending fuel injectors as claimed” (along with their
respective bores) and as taught by Mancini. Ans. 4. Indeed, Brehm teaches
that it would be possible to arrange the injectors differently from that
illustrated (i.e., “parallel to one another, for example”) which is how the
Examiner has them arranged in the Examiner’s exemplary annotated
Figure 2 of Mancini. Brehm 2:40–47; Ans. 4.
Appellant, in the Reply Brief, replicates a different annotated figure
(i.e., annotated Figure 1 of the secondary reference to Brehm) to show a

3 Claim 1 recites “second fuel injection bores radially extending through the
second dome wall.” Emphasis added.
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different orientation of these injectors. See Reply Br. 3. However, the
figure Appellant relies upon is not Mancini’s annotated Figure 2 (i.e., the
primary reference) that the Examiner has modified to show that “the
combustor will be similar to an example shown below.” Ans. 4 (annotating
Figure 2 of Mancini).
Further, in referencing Brehm’s Figure 1, and not Mancini’s Figure 2,
Appellant contends “the modification made by the Examiner to Brehm’s
figure 1 would result in a combustor that blows combustion gasses on itself.”
Reply Br. 4. However, even assuming arguendo (i.e., the resultant
combustor would blow combustion gasses radially and not axially),
Appellant does not explain why a skilled person would not incorporate a 90
degree bend into the gas flow, such as of the type depicted in Figure 2 of
Mancini. Ultimately, however, and to be clear, the Examiner is modifying
Mancini in view of Brehm whereas Appellant appears to be modifying
Brehm.
Appellant also contends that “Brehm emphasizes the importance of
mixing between the stages.” Reply Br. 6; see also id. at 7. However,
Appellant does not explain how, in the Examiner’s example embodiment,
downstream mixing of the gases from these stages fails to occur.
Accordingly, and based on the record presented, we are not persuaded
the Examiner erred in combining Mancini and Brehm for the reasons set
forth by the Examiner.
Addressing now the Examiner’s incorporation of the additional
teachings of Dailey’s intermediate wall 55, Appellant contends there was
improper rationale for such combination. See Appeal Br. 12–13; Reply
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Br. 5. Appellant presents three reasons in support of this argument. See
Appeal Br. 13.
The first is that a skilled person “would have no motivation to
combine the references.” Appeal Br. 13. Appellant replicates that portion of
Dailey relied upon by the Examiner as providing the requisite motivation,
i.e., Dailey 4:25–45. See Appeal Br. 14; Final Act. 6. Appellant contends
that “it is the presence of two stages that causes” the benefits relied upon by
the Examiner, and thus a skilled person would “have no motivation to add an
intermediate wall.” Appeal Br. 14. The Examiner disagrees noting that to
demark the boundaries of Dailey’s two stages (62, 64), Dailey employs an
intermediate wall (55) with Dailey teaching (as noted above) that “by this
arrangement different air fuel ratio’s and combustion conditions can be
provided in both regions 62, 64.” Dailey 4:27–29; see also Ans. 5. In other
words, as expressed by the Examiner, “[e]ach stage can, therefore, have
different fuel air ratios and residence times as taught by Dailey.” Ans. 5.
Appellant appears to concur stating, “[t]he addition of an intermediate wall
serves no purpose other than to separate the combustor into two stages”
(Appeal Br. 15) while acknowledging that “it is the presence of two stages
that causes” the benefits to occur (Appeal Br. 14).
Appellant further contends that “Dailey consistently uses the
expression ‘arrangement’ to describe the combustor as a whole” and we do
not disagree. Reply Br. 5. But this contention does not refute Dailey’s
employment of an intermediate wall between the stages allowing them to
operate under different conditions thereby reducing combustion by-products.
See Dailey 4:25–45. Additionally, “[t]he Examiner further notes that the
intermediate wall separating the two stages were also known in the art” and
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that “use of a known prior art structure . . . to obtain predictable results . . .
was an obvious extension of prior art teachings.” Ans. 6.
Accordingly, and based on the record presented, we are not persuaded
the Examiner lacked the requisite motivation when combining the
references, as Appellant asserts.
Next, Appellant asserts that the proposed modification would be
“unsatisfactory for its intended purpose.” Appeal Br. 15. Appellant
annotates Figure 1 of Brehm showing the proposed intermediate wall 55 of
Dailey. See Appeal Br. 16. Appellant contends that due to the angle and
orientation of the wall drawn by Appellant, the wall “would block the flow
between the two combustion stages.” Appeal Br. 16. Thus, as per
Appellant, a skilled person “would not consider adding an intermediate wall,
as per Dailey, to the combustor of Brehm, as it would hamper the normal
operation of the Brehm combustor.” Appeal Br. 17. First, it should be noted
that the Examiner is modifying Mancini’s combustor, not Brehm’s
combustor. Regardless, Appellant’s contention regarding Brehm is
premised upon speculation as to how Dailey’s wall 55 would be orientated
within that combustor. See also Ans. 5. Appellant expresses a desire to not
hamper normal flow, but Brehm already discloses a “deflecting section 12”
that presently hampers (deflects) flow. Brehm 2:53–3:11. Thus, Appellant’s
premise that a skilled person, relying on Brehm, would not hamper flow is
faulty when Brehm already teaches doing exactly that.
For these reasons, we are not persuaded that the Examiner’s proposed
combination would render Mancini’s combustor unsatisfactory for its
intended purpose. See Appeal Br. 15.
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Lastly, Appellant contends that the Examiner’s combined teachings
“is a clear case of speculation.” Appeal Br. 17. This is because Dailey’s
wall “is merely present to schematically show two stages of a combustor.”
Appeal Br. 17. However, Dailey not only illustrates an intermediate wall,
but also discusses same in the text to achieve two stages. See Dailey 4:25–
26 (“main 64 and pilot 62 regions are partially separated by a further wall
55”). Hence, it is not made clear how the incorporation of Dailey’s wall 55
is “a clear case of speculation” on the part of the Examiner when Dailey
actually shows and discusses such a wall between adjacent stages. Appeal
Br. 17. Accordingly, we are not persuaded by Appellant’s contention that
the Examiner lacked “the appropriate factual basis to justify such a
combination.” Appeal Br. 18.
In summation, we are not persuaded the Examiner erred in rejecting
claim 1, and dependent claims 2, 5–8, 10–17, 19, 20, as being unpatentable
over Mancini, Brehm, Dailey, and Stenger. We sustain their rejection.
The rejections of (a) claims 3 and 4 as unpatentable over Mancini, Brehm,
Dailey, Stenger, and Markowski; (b) claim 9 as unpatentable over Mancini,
Brehm, Dailey, Stenger, and Zupanc; and, (c) claim 18 as unpatentable over
Mancini, Brehm, Dailey, Stenger, and Alary
Appellant does not present separate arguments regarding these
separate rejections. See Appeal Br. 18–19. Instead, Appellant states that
“[f]or the foregoing reasons,” the “[w]ithdrawal of each of the rejections” is
requested. Appeal Br. 19. We are not persuaded by such statements and as
such, we sustain the rejections of claims 3, 4, 9, and 18 in view of the
additional reliance by the Examiner upon Markowski, Zupanc, and Alary as
noted above.
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CONCLUSION
In summary:
Claim(s)
Rejected
35 U.S.C. § Reference(s)/
Basis
Affirmed Reversed
1–16 112 Indefiniteness 1–16
1, 2, 5–8,
10–17, 19,
20
103 Mancini,
Brehm,
Dailey,
Stenger
1, 2, 5–8, 10–
17, 19, 20

3, 4 103 Mancini,
Brehm,
Dailey,
Stenger,
Markowski
3, 4
9 103 Mancini,
Brehm,
Dailey,
Stenger,
Zupanc
9
18 103 Mancini,
Brehm,
Dailey,
Stenger,
Alary
18
Overall
Outcome
1–20
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