UNITED TECHNOLOGIES CORPORATION

Patent Trials and Appeals Board

Mar 23, 2021

2020004480 (P.T.A.B. Mar. 23, 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.
14/895,784 12/03/2015 James B. Hoke 1213-28216WOUS 4914
11943 7590 03/23/2021
Getz Balich LLC
10 Waterside Drive, Suite 205
Farmington, CT 06032
EXAMINER
BURKE, THOMAS P
ART UNIT PAPER NUMBER
3741
NOTIFICATION DATE DELIVERY MODE
03/23/2021 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):
shenry@getzbalich.com
uspto@getzbalich.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
____________

Ex parte JAMES B. HOKE, RANDAL G. MCKINNEY, and
ALBERT K. CHEUNG
____________

Appeal 2020-004480
Application 14/895,784
Technology Center 3700
____________

Before JENNIFER D. BAHR, MICHELLE R. OSINSKI, and
SEAN P. O’HANLON, Administrative Patent Judges.

O’HANLON, Administrative Patent Judge.
DECISION ON APPEAL

STATEMENT OF THE CASE
Appellant1 appeals under 35 U.S.C. § 134(a) from the Examiner’s
decision to reject claims 1–4, 6, 8–12, and 14–23.2 We have jurisdiction
over this appeal under 35 U.S.C. § 6(b). We REVERSE.

1 We use the term “Appellant” to refer to “applicant” as defined in 37 C.F.R.
§ 1.42. Appellant identifies the real party in interest as Raytheon
Technologies Corporation, formerly United Technologies Corporation. See
Miscellaneous Incoming Letter (filed Apr. 23, 2020).
2 Claims 5, 7, and 13 are canceled. Amendment 3–4 (filed Dec. 4, 2019).
Appeal 2020-004480
Application 14/895,784

2
In explaining our Decision, we refer to the Specification filed
December 3, 2015 (“Spec.”), the Final Office Action mailed January 22,
2020 (“Final Act.”), the Appeal Brief filed February 4, 2020 (“Appeal Br.”),
the Examiner’s Answer mailed March 30, 2020 (“Ans.”), and the Reply
Brief filed May 29, 2020 (“Reply Br.”).
SUMMARY OF THE INVENTION
Appellant’s claimed invention relates to gas turbine engines.
Spec. ¶ 2. Claims 1, 14, and 18 are independent. Claim 14, reproduced
below from page 22 (Claims Appendix) of the Appeal Brief, is illustrative of
the claimed subject matter:
14. A turbofan gas turbine engine combustor, comprising:
a first fuel injection system in communication with a
combustion chamber;
a second fuel injection system that communicates with
said combustion chamber downstream of said first fuel
injection system to define a forward combustion zone forward
of said second fuel injection system and a downstream
combustion zone aft of said second fuel injection system,
wherein said forward combustion zone defines twenty percent
to fifty percent of a total volume of said combustor chamber
and said downstream combustion zone defines fifty percent to
eighty percent of said total volume of said combustor chamber;
an inner liner;
an outer liner; and
a forward assembly between said inner liner and said
outer liner, wherein said forward assembly includes a bulkhead
liner that defines a bulkhead height, and
wherein said inner liner and said outer liner are radially
spaced between one hundred percent and two hundred percent
of said bulkhead height axially proximate to said second fuel
injection system.
Appeal 2020-004480
Application 14/895,784

3
REFERENCES
The Examiner relies on the following prior art references in rejecting
the claims on appeal:
Shekleton US 5,277,021 Jan. 11, 1994
DuBell US 5,749,219 May 12, 1998
Matsumoto US 2007/0089419 A1 Apr. 26, 2007
Burd US 2007/0125093 A1 June 7, 2007
Dodo US 2007/0256416 A1 Nov. 8, 2007
REJECTIONS3
I. Claims 14–20 stand rejected under 35 U.S.C. § 103 as being
unpatentable over DuBell, Matsumoto, and Burd.
II. Claims 1–4, 6, 8–12, 21, and 22 stand rejected under 35 U.S.C. § 103
as being unpatentable over DuBell, Dodo, Matsumoto, and Burd.
III. Claim 23 stands rejected under 35 U.S.C. § 103 as being unpatentable
over DuBell, Dodo, Matsumoto, Burd, and Shekleton.
ANALYSIS
Rejection I – Obviousness based on DuBell, Matsumoto, and Burd
In rejecting independent claim 14, the Examiner finds that DuBell
discloses a gas turbine engine combustor substantially as recited, including
an inner liner, an outer liner, and a bulkhead having a bulkhead height, but
does not disclose explicitly the recited sizes of the forward and downstream
combustion zones and the radial spacing of the inner and outer liners. Final
Act. 3–4. The Examiner relies on Matsumoto to teach the recited sizing of

3 The Final Action included a rejection of claim 7 under 35 U.S.C. § 103
(see Final Act. 16–17), but this claim was canceled in the Amendment filed
on April 25, 2018, and, thus, is not involved in this appeal.
Appeal 2020-004480
Application 14/895,784

4
the combustion zones. Id. at 4–5. The Examiner finds that Burd teaches
managing the height between inner and outer liners of a combustor to reduce
combustor residence time. Id. at 5 (citing Burd ¶ 41). The Examiner finds
that “the height between the inner and outer liner walls is recognized as a
result effective variable, i.e., a variable which achieves a recognized result.”
Id. (citing In re Antonie, 559 F.2d 618 (CCPA 1977);
MPEP § 2144.05(II)(B)). The Examiner determines that “it is not inventive
to discover the optimum workable range by routine experimentation, and it
would have been obvious . . . to modify DuBell . . . to provide the height
between combustor liner walls as taught by Burd in order to reduce
combustor residence time.” Id. (citing In re Aller, 220 F.2d 454, 456 (CCPA
1955); MPEP § 2144.05(II)(A)).
Appellant argues that “Burd is incapable of establishing the general
conditions as alleged in the Office Action.” Appeal Br. 13 (citing Burd
¶ 41). Appellant asserts that Burd teaches “several ratio ranges of H1/H3
which may impact combustor residence times. However, the disclosure of
Burd is limited to ratios of only those particular combustor heights (i.e., the
bulkhead height H1 and the combustor exit height H3).” Id. at 14 (citing
Burd ¶ 43). According to Appellant, “the teaching of Burd, that the
combustor exit height H3 can be optimized relative to the bulkhead height
H1, cannot reasonably be understood to also apply to every other radial
spacing between liner panels of the combustor.” Id. at 15.
The Examiner responds that DuBell’s “second fuel injection system
(36, 34, and 28) is ‘axially proximate’ to the combustor exit.” Ans. 4 (citing
DuBell, Fig. 1). The Examiner explains “that the term ‘proximate’ is
defined by Merriam-Webster’s online dictionary as ‘very or relatively close
Appeal 2020-004480
Application 14/895,784

5
or near.’” Id. (citing Merriam-Webster.com Dictionary, https://
www.merriamwebster.com/dictionary/proximate (accessed March 9, 2020)).
According to the Examiner, “the relative heights [in DuBell’s combustor]
which are optimized include both the bulkhead height as well as a height
which is axially proximate to the second fuel injection system.” Id. at 5
(citing DuBell, Fig. 1).
In the Reply Brief, Appellant contends that DuBell’s fuel nozzle 36
(i.e., second fuel injection system) is “not ‘very or relatively close or near,’
to the combustor exit 26 as the Answer defines ‘proximate.’” Reply Br. 2
(citing Ans. 4). Rather, “[t]he combustor of DuBell includes a substantial
axial spacing between fuel nozzles 36 in the second zone and the combustor
exit 26.” Id. (citing DuBell, Fig. 1). We agree with Appellant.
DuBell discloses, with reference to Figure 1, annular combustor 10
including outer liner 16 and inner liner 20. DuBell, 3:20–27. Figure 1 of
DuBell is reproduced below.

Appeal 2020-004480
Application 14/895,784

6
Figure 1 of DuBell depicts a combustor including primary zone 30 fueled by
nozzle 31 (id. at 3:34–40) and second zone 32 fueled by nozzle 36 (id. at
3:48–50). Aft end 26 is open to discharge combustion products to a turbine
(not shown). Id. at 3:27–30. As discussed above, the Examiner takes the
position that aft end 26 of the combustor is axially proximate nozzle 36 (i.e.,
the “second fuel injection system” as recited in claim 14). See Ans. 4–5.
However, although the height of DuBell’s annular combustor at aft end 26
appears to correspond to a radial spacing of outer liner 16 and inner liner 20,
we agree with Appellant that aft end 26 is not “very or relatively close or
near” nozzle 36 (i.e., the second fuel injection system). See Reply Br. 2.
Rather, Figure 1 of DuBell appears to show that aft end 26 and nozzle 36 are
separated by a significant amount of axial space (i.e., nearly half of the
overall combustor length), and the radial spacing between the inner and
outer liners appears to vary between aft end 26 and nozzle 36—notably, the
liner spacing at aft end 26 appears to be substantially smaller than the
spacing at fuel nozzle 36.
Moreover, Appellant’s Specification describes “a height H of the
combustion chamber 66 between the liners 72, 74 at the radial fuel injection
system 120 location.” Spec. ¶ 77 (emphasis added). According to the
Specification, “[t]he height H as defined herein is the radial distance
between the liner panels 72, 74 within the combustion chamber 66
proximate the radial fuel injection system 120 location.” Id. (emphasis
added). In other words, in view of the Specification, the radial spacing
between inner and outer liners “axially proximate to said second fuel
injection system” as recited in claim 14 appears to mean the height between
the inner and outer liners at the second fuel injection system location. Given
Appeal 2020-004480
Application 14/895,784

7
that DuBell’s aft end 26 is axially spaced from nozzle 36, the radial spacing
between the liners at aft end 26 is not at the second fuel injection system.
Thus, the Examiner’s interpretation that applying Burd’s teaching of
combustor exit height to DuBell’s combustor would result in the recited liner
spacing proximate the second fuel injector system is not supported by the
evidence.
The Examiner also appears to rely on Burd’s statement that combustor
residence time can be reduced by management of the liner spacing and air
flow through the combustor as teaching the recited liner spacing. Ans. 5–6
(citing Burd ¶ 41). Initially, the discussion referenced by the Examiner
precedes and introduces the exit height discussion of paragraph 42 noted
above and, thus, does not appear to be a distinct teaching as suggested by the
Examiner. Furthermore, the Examiner fails to explain how the discussion of
cylinder and truncated cone volumes (see id. at 6) relates to the recited liner
spacing proximate the second fuel injection system.
Although Burd teaches that combustor residence time can be reduced
by managing the ratio between bulkhead height H1 and exit height H3 (Burd
¶¶ 41–43), it is unclear how or why this disclosure would have led one of
ordinary skill in the art to optimize the radial spacing of DuBell’s inner and
outer liners at a location “axially proximate to said second fuel injection
system” as recited in claim 14. Accordingly, for the foregoing reasons, we
do not sustain the rejection of claim 14, or its dependent claims 15–17, as
being unpatentable over DuBell, Matsumoto, and Burd.
Independent claim 18 contains similar recitations as claim 14,
including the liner spacing proximate the second fuel injection system, and
the Examiner relies on the same deficient findings as for claim 14. Appeal
Appeal 2020-004480
Application 14/895,784

8
Br. 23 (Claims App.); Final Act. 7–9. Accordingly, for the same reasons as
set forth above, we do not sustain the rejection of claim 18, or its dependent
claims 19 and 20, as being unpatentable over DuBell, Matsumoto, and Burd.
Rejections II and III – Obviousness based on DuBell, Matsumoto,
Burd, and one or more of Dodo and Shekleton
Independent claim 1 recites a similar liner spacing proximate the
second fuel injector system as discussed above regarding claim 14. Appeal
Br. 20 (Claims App.). The Examiner relies on the same deficient findings as
discussed above regarding claim 14. Final Act. 10–13. The Examiner relies
on Dodo and Shekleton for teaching additional features, but does not
articulate any findings or reasoning that would remedy the aforementioned
deficiency in the combination of DuBell, Matsumoto, and Burd. See id.
at 10–18. Accordingly, for the same reasons as set forth above, we do not
sustain the rejection of claim 1, or its dependent claims 2–4, 6, 8–12, and
21–23, as being unpatentable over DuBell, Matsumoto, Burd, and one or
more of Dodo and Shekleton.
CONCLUSION
In summary,
Claim(s)
Rejected 35 U.S.C. § Reference(s)/Basis Affirmed Reversed
14–20 103 DuBell,
Matsumoto, Burd
14–20
1–4, 6, 8–12,
21, 22
103 DuBell, Dodo,
Matsumoto, Burd
1–4, 6, 8–12,
21, 22
Appeal 2020-004480
Application 14/895,784

9
Claim(s)
Rejected 35 U.S.C. § Reference(s)/Basis Affirmed Reversed
23 103 DuBell, Dodo,
Matsumoto, Burd,
Shekleton
23
Overall
Outcome
1–4, 6, 8–12,
14–23
REVERSED