Mitsubishi Hitachi Power Systems, Ltd.

Patent Trials and Appeals Board

Dec 24, 2020

2020000417 (P.T.A.B. Dec. 24, 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.
14/760,519 07/13/2015 Makoto KISHI 2015-0872A 6929
513 7590 12/24/2020
WENDEROTH, LIND & PONACK, L.L.P.
1025 Connecticut Avenue, NW
Suite 500
Washington, DC 20036
EXAMINER
KIM, CRAIG SANG
ART UNIT PAPER NUMBER
3741
NOTIFICATION DATE DELIVERY MODE
12/24/2020 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):
eoa@wenderoth.com
kmiller@wenderoth.com
PTOL-90A (Rev. 04/07)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
____________

Ex parte MAKOTO KISHI, TAKASHI SONODA, SHINYA UCHIDA,
SOSUKE NAKAMURA, YOSHIKAZU MATSUMURA, SATOKO FUJII,
TETSUYA YABE, and RYOICHI HAGA
____________

Appeal 2020-000417
Application 14/760,519
Technology Center 3700
____________

Before DANIEL S. SONG, MICHELLE R. OSINSKI, and
GEORGE R. HOSKINS, Administrative Patent Judges.

HOSKINS, Administrative Patent Judge.

DECISION ON APPEAL
Pursuant to 35 U.S.C. § 134(a), Appellant1 appeals from the
Examiner’s decision rejecting all pending claims 8–10, 12–15, 17, and 18
under 35 U.S.C. § 103(a) as unpatentable over Szepek (US 7,457,688 B2,
issued Nov. 25, 2008) and Pearce (US 2005/0274115 A1, published Dec. 15,
2005). Claims 1–7, 11, and 16 have been canceled. See Final Act. 2;
Appeal Br. 2.
We AFFIRM.

1 We use the word “Appellant” to refer to “applicant” as defined in
37 C.F.R. § 1.42. The Appeal Brief identifies Mitsubishi Hitachi Power
Systems, Ltd., as the real party in interest. Appeal Br. 2.
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Application 14/760,519

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CLAIMED SUBJECT MATTER
The present application generally concerns a device for controlling the
combustor in a gas turbine system, which is used to generate electrical
power. See Spec. ¶¶ 1–2, 5. Claim 8 is illustrative of the claims on appeal,
and it recites:
8. A gas turbine combustor control device comprising:
a load interruption detector which detects a load interruption
of a gas turbine;
a delay circuit to set a delay time, based on detection of the
load interruption;
a pilot nozzle flow rate control unit which increases an
amount of premixed fuel supplied to a pilot nozzle, based on
detection of the load interruption;
a first main nozzle flow rate control unit which reduces an
amount of premixed fuel supplied to a first main nozzle to a first
amount, based on detection of the load interruption; and
a second main nozzle flow rate control unit which reduces
an amount of premixed fuel supplied to a second main nozzle to
a second amount which is different from the first amount, based
on detection of the load interruption, and then further reduces the
amount of premixed fuel supplied to the second main nozzle
from the second amount to a third amount which is smaller than
the first amount and the second amount after an elapse of the
delay time,
wherein the second main nozzle flow rate control unit
reduces the amount of premixed fuel supplied to the second main
nozzle from the second amount to the third amount while the first
main nozzle flow rate control unit is reducing the amount of
premixed fuel supplied to the first main nozzle to the first
amount.
Appeal Br. 9 (Claims App.).
OPINION
Appellant argues for the patentability of all claims 8–10, 12–15, 17,
and 18 together as one group, without separately arguing different claims in
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Application 14/760,519

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the group. See Appeal Br. 5–7 (arguing independent claim 8); id. at 7
(arguing independent claim 18 is “patentable . . . for reasons similar to those
set forth above in support of independent claim 8”). Accordingly, we select
claim 8 as representative, and we decide the appeal as to all claims on the
basis of claim 8. See 37 C.F.R. § 41.37(c)(1)(iv).
The Examiner finds Szepek discloses the claimed gas turbine
combustor control device, except for the delay circuit which sets a delay
time for further reducing the amount of fuel supplied to the second main
nozzle from the second amount to the third amount. Final Act. 3–4
(annotating Szepek Fig. 14 to illustrate findings). The Examiner finds
Pearce discloses a similar gas turbine fuel control system, which includes a
delay circuit to set a delay time for reducing fuel delivery. Id. at 4–5, 8
(citing Pearce, Fig. 12, ¶¶ 6, 10–12). The Examiner acknowledges Pearce’s
time delay “is based on a command input rather than a . . . load
interruption” as required by claim 8, but determines Pearce’s time delay
“could have been applied to reduction of fuel based on detection of a load
interruption, because reduction in fuel occurs in both cases, and controlling
the reduction of fuel would have prevented loss of flame due to decreasing
the fuel supply too rapidly” in both cases. Id. (emphases added). The
Examiner therefore determines it would have been obvious to modify
Szepek to include a delay circuit when supplying fuel to the second main
nozzle, based on detecting a load interruption as claimed, in order to
“protect[] against loss of flame resulting from decreasing the fuel supply too
rapidly.” Id. at 5, 8–9.

2 The rejection refers to Figure 2 but, in context, it is clear that Figure 1 was
intended.
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Application 14/760,519

4
Appellant firstly argues “Szepek fails to teach active control to further
reduce the amount” of fuel supplied to the second main nozzle from the
second amount to the third amount. Appeal Br. 5 (emphasis by Appellant).
It is unclear what Appellant means by “active” control here. The
Examiner correctly observes this term does not appear in claim 8. See
Ans. 4. As far as we have been able to discern, this term also does not
appear in Appellant’s Specification. We thus conclude Appellant’s
argument is unpersuasive, because it relies on an unclaimed limitation. We
further agree with the Examiner’s finding that Szepek does disclose an
“active” control of fuel supply to the second main nozzle, in that Szepek
reduces the amount of fuel supplied to the second main nozzle (Figure 14,
WPM2) upon detecting a decrease in the electrical load demand on the
turbine from a base load of 155 Megawatts to an island load of
85 Megawatts in response to a grid separation event. See Ans. 4–5; Szepek,
Figs. 13–14, 9:21–65, 11:62–66.
Appellant secondly argues, in the Reply Brief, that Szepek’s Figure 14
fails to reflect “that the fuel flow rates WPM2 and WPM3 decrease based on
the detection of load interruption” as recited in claim 8. Reply Br. 2
(emphasis by Appellant). Appellant’s view is that Figure 14 instead
“discloses only the captured data of Line Breaker Status L52LX1 and the
fuel flow rates WPM2 and WPM3.” Id. (emphasis by Appellant).
We are not persuaded, because Appellant overlooks the interaction
between Szepek’s Figures 13 and 14, and the accompanying written
description. Szepek describes Figures 13 and 14 as illustrating a “test . . .
performed using a General Electric (GE) gas turbine Mark VI engine control
software in real time integrated simulation using [Szepek’s] transient fuel
control algorithm.” Szepek, 9:21–24. The test “demonstrate[d] the
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Application 14/760,519

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capabilities and limitations of the transient fuel control algorithm to respond
to grid separation and to tune the control algorithms for island mode.” Id.
at 9:27–29 (emphasis added); id. at 9:43–55, 11:62–63 (Figs. 13 and 14
correspond to Case 1B of Szepek’s simulations). Thus, in Figure 14, the
status change of “L52LX1” from “1” to “0” at about 6 seconds corresponds
to disconnecting the turbine from the power utility grid, so that the turbine
needs to supply only enough electrical power to support local demand within
the power plant. See id. at Fig. 1 (illustrating power utility grid 12, circuit
breaker 22, gas turbine generator 10, and local power load 14), 3:59–65,
6:51–61, 10:58–59 (Table 4, L52LX1). This corresponds to detecting a load
interruption, as required by claim 8.
Appellant thirdly argues Pearce “fails to teach separately controlling
fuel amounts supplied to a plurality of main nozzles,” as is required by
claim 8, so “Pearce fails to cure the deficiencies of Szepek.” Appeal Br. 6
(emphasis by Appellant).
We, however, agree with the Examiner’s finding that there is no
deficiency of Szepek to cure in this regard. See Ans. 6–7. Szepek discloses
separately controlling the fuel amounts supplied respectively to a pilot
nozzle (Figure 14, WPM1), a first main nozzle (WPM3), and a second main
nozzle (WPM2). See Final Act. 3–4; Szepek, Fig. 14, 10:60–65 (Table 4);
see also id. 5:57–6:3 (Fig. 4 illustrates three nozzles groups PM1, PM2, and
PM3, separately controlled by three gas control valves GCV1, GCV2,
GCV3). Thus, while it is true that Pearce refers only generally to controlling
the quantity of fuel delivered to a gas turbine without indicating that the fuel
is supplied via separately controlled fuel nozzles, this does not demonstrate
Examiner error in finding that the combination of Szepek and Pearce
includes three separately controlled fuel nozzles.
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Appellant fourthly argues “there is no teaching or suggestion in either
Szepek or Pearce that a delay time is set based on detection of the load
interruption,” as required by claim 8. Appeal Br. 6. Appellant similarly
asserts “there is no teaching or suggestion in either Szepek or Pearce that the
amount of premixed fuel supplied to the second main nozzle is reduced from
the second amount to a third amount after an elapse of a predetermined delay
time.” Id.
We, however, agree with the Examiner’s determination that the
combination of Szepek and Pearce rationally leads to these claim
requirements, without hindsight. See Ans. 7–9. As discussed in detail
above, Szepek discloses reducing the amount of fuel delivered to a second
main nozzle (WPM2), from a second amount to a third amount, in response
to detecting a load interruption. See, e.g., Szepek Fig. 14; Final Act. 4
(annotating Szepek’s Figure 14 to identify the second amount and the third
amount). Pearce, meanwhile, discloses that a time delay circuit may be
employed within the fuel flow signal control unit of a gas turbine combustor,
“to cause a change in the quantity of fuel delivered . . . at an increasing or
decreasing rate independent of the rate of change required by” an inputted
demand signal from an external source. Pearce ¶¶ 6, 10 (emphases added).
The reason for including such a time delay circuit, according to Pearce, is
“to protect against undesired operation of the engine, such as loss of flame
from decreasing the fuel supply too rapidly.” Id. ¶ 11. These combined
disclosures of Szepek and Pearce provide a rational basis without hindsight,
as articulated in the Examiner’s rejection, for including a time delay circuit
within Szepek’s second main nozzle: to prevent loss of flame when the
supplied fuel is reduced in response to detecting a load interruption. See
Final Act. 4–5.
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Application 14/760,519

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Appellant fifthly argues “due to the above-noted features, the claimed
invention produces unexpected results sufficient to show nonobviousness,”
because “the claimed invention can more reliably prevent misfire of a
combustor than prior art devices and methods such as those in Szepek and
Pearce.” Appeal Br. 7 (citing Spec. ¶¶ 29–31). To the extent this argument
is a re-packaging of Appellant’s previous contentions, it is not persuasive for
the reasons provided above.
In addition, the cited disclosures in Appellant’s Specification do not
establish any unexpected results in Appellant’s claimed invention versus the
prior art. See, e.g., In re Baxter Travenol Labs., 952 F.2d 388, 392 (Fed.
Cir. 1991) (alleged unexpected results must be shown to be unexpected
compared with the closest prior art). The Specification merely indicates the
claimed invention is designed “to reliably prevent misfire of the
combustor . . . by promoting flame diffusion from a main system.” Spec.
¶¶ 29–31. There is no comparison of the claimed invention versus prior art
combustor fuel control systems, much less any suggestion that the results
achieved by the claimed invention might be unexpected versus prior art
systems. Id. “[I]t is well settled that unexpected results must be established
by factual evidence,” not “[m]ere argument or conclusory statements.” In re
Geisler, 116 F.3d 1465, 1469–70 (Fed. Cir. 1997). Appellant’s
Specification does not reflect, and Appellant does not point us to other
evidence that might tend to demonstrate, any unexpected results here.
We must “consider[] the evidence as a whole before reaching a
conclusion on the claims’ patentability under 35 U.S.C. § 103(a).” In re
Brandt, 886 F.3d 1171, 1176 (Fed. Cir. 2018) (citing Leo Pharm. Prods.,
Ltd. v. Rea, 726 F.3d 1346, 1357 (Fed. Cir. 2013) and In re Huai–Hung Kao,
639 F.3d 1057, 1066 (Fed. Cir. 2011)). Therefore, weighing the entirety of
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Application 14/760,519

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the evidence in the record before us as set forth above, both for and against
obviousness, we conclude the Examiner has the better position regarding the
unpatentability of claim 8. As set forth above, the prior art cited by the
Examiner supports the conclusion of obviousness, and Appellant’s reliance
on unexpected results having been achieved is not supported by evidence in
the present record.
Accordingly, we sustain the rejection of claims 8–10, 12–15, 17,
and 18 as having been obvious over Szepek and Pearce.
SUMMARY OF DECISION
In summary, we affirm the sole rejection presented on appeal, as
follows:
Claim(s)
Rejected
35 U.S.C.
§
Reference(s) / Basis Affirmed Reversed
8–10, 12–15,
17, 18
103 Szepek, Pearce 8–10, 12–15,
17, 18

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