Perlak, Jeffrey F. et al.

Patent Trials and Appeals Board

Dec 27, 2019

14740636 - (D) (P.T.A.B. Dec. 27, 2019)

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.
14/740,636 06/16/2015 Jeffrey F. Perlak 81813US1;
67097-3236PUS1
6832
54549 7590 12/27/2019
CARLSON, GASKEY & OLDS/PRATT & WHITNEY
400 West Maple Road
Suite 350
Birmingham, MI 48009
EXAMINER
BURKE, THOMAS P
ART UNIT PAPER NUMBER
3741
NOTIFICATION DATE DELIVERY MODE
12/27/2019 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):
ptodocket@cgolaw.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte JEFFREY F. PERLAK, JOSEPH B. STAUBACH, FREDERICK
M. SCHWARZ, and JAMES D. HILL
Appeal 2019-003949
Application 14/740,636
Technology Center 3700
BEFORE JILL D. HILL, LEE L. STEPINA, and ARTHUR M. PESLAK,
Administrative Patent Judges.
STEPINA, 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 12–14, 17, and 26. 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. Appellant identifies the real party in interest as United Technologies
Corporation. Appeal Br. 2.
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Application 14/740,636

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CLAIMED SUBJECT MATTER
The claims are directed to a temperature-modulated recuperated gas
turbine engine. Claim 12, reproduced below with emphasis added, is
illustrative of the claimed subject matter:
12. A recuperated gas turbine engine comprising:
an engine core including a compressor section, a
combustor section, and a turbine section;
an exhaust duct downstream of the turbine section for
receiving a hot turbine exhaust stream from the turbine section,
the exhaust duct including a heat exchanger and a temperature-
control module upstream of the heat exchanger, the temperature-
control module operable to influence at least one of temperature
and flow of the hot turbine exhaust stream, the heat exchanger
aft of the turbine section;
a compressor bleed line leading from the compressor
section into the heat exchanger and a compressor return line
leading from the heat exchanger into the engine core upstream of
the combustor section; and
a controller in communication with at least the compressor
bleed line and the temperature-control module, the controller
configured to selectively regulate feed of compressed air through
the compressor bleed line into the heat exchanger and
configured to selectively regulate a temperature and flow of the
hot turbine exhaust stream with respect to the heat exchanger.
Appeal Br. 8 (Claims Appendix).
REFERENCES
The prior art relied upon by the Examiner is:
Name Reference Date
Templin US 3,717,994 Feb. 27, 1973
Mackay US 2010/0229525 A1 Sept. 16, 2010
Merchant US 2010/0247304 A1 Sept. 30, 2010
Robinson US 2013/0318988 A1 Dec. 5, 2013

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REJECTIONS
I. Claims 12, 13, and 17 are rejected under 35 U.S.C. § 103 as
unpatentable over Templin and Robinson. Final Act. 3.
II. Claim 14 is rejected under 35 U.S.C. § 103 as unpatentable
over Templin, Robinson, and Mackay. Final Act. 5.
III. Claim 26 is rejected under 35 U.S.C. § 103 as unpatentable
over Templin, Robinson, and Merchant. Final Act. 6.
OPINION
Rejection I
Location of Heat Exchanger
The Examiner finds that Templin discloses a recuperated gas turbine
engine having most of the limitations of claim 12, including, inter alia, a
turbine section and a heat exchanger. Final Act. 3. The Examiner notes that
Templin does not disclose a temperature-control module upstream of the
heat exchanger that is operable to selectively modulate a temperature and
flow of the hot turbine exhaust stream with respect to the heat exchanger.
Id. Nonetheless, the Examiner finds that Robinson discloses a temperature-
control module (BY) operable to influence at least one of temperature and
flow. Id. (citing Robinson ¶ 39, Fig. 1). The Examiner concludes that it
would have been obvious to include a temperature-control module in the
engine of Templin to guide the working medium through or past the turbine
heat exchanger and to optimize heat exchanger flow, heat exchanger loss,
and heat exchanger efficiency correlation, as well as the core engine
thermodynamic efficiency. Final Act. 4 (citing Robinson ¶ 20).
Appellant argues that the Examiner “provides no reason for why it
would have been obvious to locate Templin’s heat exchanger 23 ‘aft of the
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turbine section.’” Appeal Br. 3. Appellant asserts that the reason provided
in the Advisory Action, mailed October 17, 2018, namely, that the relocation
is “merely rearranging parts,” is conclusory because the Examiner does not
provide a motivation for doing so. Id. According to Appellant, because
there is no benefit and because the Examiner has not established that the
modification is possible, the proposed relocation would not have been
obvious. Id. at 3–4.
In response, the Examiner notes that Templin and Robinson show
different known arrangements for heat exchangers that heat fluid exiting a
turbine. Ans. 4. According to the Examiner, it would have been an obvious
matter of design choice to use the location aft of the turbine, as shown by
Robinson, “since Appellant has not disclosed that the positioning of the heat
exchanger solves any stated problem or is for any particular purpose and it
appears that the invention would perform equally well with the placement of
the heat exchanger of either Templin or Robinson.” Id.
Appellant replies that because the Examiner has shifted the grounds
from “rearrangement of parts” to “design choice,” it is unclear what grounds
is being used. Reply Br. 2. According to Appellant, in any event, the
Examiner has not stated a benefit for relocating the heat exchanger, or
whether the heat exchanger would fit or could be relocated in an automobile.
Id.
Appellant’s argument that the Examiner is using “shifting grounds for
the § 103 rejection,” does not apprise us of Examiner error. Listed under the
heading “Rearrangement of Parts” in the MPEP is In re Kuhle, 526 F.2d 553
(CCPA 1975), which states that “the particular placement of a contact in a
conductivity measuring device was held to be an obvious matter of design
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choice.” MPEP §2144(VI)(C). Thus, “rearrangement of parts” and “design
choice” rely on the same legal premise. As to whether the rejection is proper
(regardless of whether the Examiner phrases the rejection in terms of design
choice or rearrangement of parts), as the Examiner correctly notes, the
question is whether the position of the heat exchanger is for a particular
purpose to perform a function that is different than in the prior art. In other
words, no benefit is required. See In re Gal, 980 F.2d 717 (Fed.Cir.1992)
(finding of “obvious design choice” precluded where the claimed structure
and the function it performs are different from the prior art).
Here, Robinson has the same structure (aft of the turbine) and
performs the same function of using turbine exhaust to heat gas flow in the
heat exchanger (see Robinson ¶ 38). Given that Templin’s heat exchanger is
aft (downstream) of the turbine in a flow direction and uses turbine exhaust
to heat the gas flowing to heat exchanger 23, the Examiner’s use of design
choice is appropriate. Moreover, Templin generally relates to “regenerative
gas turbine engines,” and is not limited to automobiles. Templin, 1:4–5.
Appellant does not explain adequately why arranging the components of
Templin as in another known regenerative gas turbine engine, namely,
Robinson, which has the same order of flow, would not function in the same
manner
Control of Exhaust
Appellant also argues that the rejection is improper because it fails to
view the references as a whole in that Templin and Robinson take opposite
approaches to managing a heat exchanger. Appeal Br. 4. According to
Appellant, Templin manages the heat exchanger by controlling compressor
air flow into the heat exchanger, whereas Robinson is controlling turbine
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exhaust flow into the heat exchanger. Id. Appellant contends that because
Templin already manages its heat exchanger by controlling compressor air
flow, “the rejection fails to establish that there would be any need or benefit
to controlling turbine exhaust flow in Templin to manage the heat
exchanger.” Id. Appellant asserts that, moreover, because “Templin wants
to take full advantage of its heat exchanger … there is no reason to reduce
the volume and/or temperature of the hot turbine exhaust stream flowing
through Templin’s duct 22 as taught by Robinson, and as the rejection seems
to suggest.” Id.
In response, the Examiner notes that Robinson is directed to operating
the heat exchanger so that heat exchanger loss and core engine efficiency are
optimized. Ans. 5. According to the Examiner, this teaching is consistent
with Templin because both Templin and Robinson “are concerned with
operating the gas turbine system in a way that may optimize the
thermodynamic efficiency of the engine e.g., mitigating a loss of energy in
the form of heat.” Id. Explaining the rationale for the rejection, the
Examiner states that “the modification of Templin is to include the concept
of providing bypass means for optionally guiding exhaust from the turbine
section to pass through the heat exchanger or around the heat exchanger in
order to optimize thermodynamic efficiency, as taught by Robinson.” Id.
In reply, Appellant contends that Templin avoids heat loss during a
“cold start” to maximize fuel economy by bypassing heat exchanger 23
during starting, but that “100% of the flow from Templin’s compressor
bleed line passes through the heat exchanger 23 during normal operation.”
Reply Br. 2. According to Appellant, implementing a bypass “in Templin
would cause Templin to not use the full capacity of its heat exchanger during
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non-startup conditions. There is no reason for such a modification in
Templin.” Id. at 3.
The Examiner has the better position. “When determining the
patentability of a claimed invention which combines two known elements,
‘the question is whether there is something in the prior art as a whole to
suggest the desirability, and thus the obviousness, of making the
combination.’” In re Beattie, 974 F.2d 1309, 1311–12 (Fed. Cir. 1992)
(quoting Lindemann Maschinenfabrik GMBH v. American Hoist & Derrick
Co., 730 F.2d 1452, 1462 (Fed. Cir. 1984)).
Here, although we appreciate Appellant’s position that there would be
no “need or benefit to controlling turbine exhaust flow in Templin to
manage the heat exchanger” (Reply Br. 3), Templin would benefit from this
arrangement in the same way that Robinson benefits. Specifically, Templin
would continue to control the flow to the heat exchanger to bypass the heat
exchanger during start-up using the compressor flow and then would bypass
the turbine exhaust flow to the heat exchanger for improved thermodynamic
efficiency as in Robinson.2 Robinson discloses operating under stationary
conditions or within the operating range within the operating limits, at the
maximum combustor temperature “for a predefined power output, while
maximum efficiency levels are preferably kept in one or multiple
components of the engine,” and using the bypass for high outputs, in
particular full load, “in such a way that the heat exchanger flow, heat

2 The Examiner’s proposed modification is akin to providing adjustment of
both the hot and cold water in a shower, rather than providing adjustment of
only the cold water while requiring the hot water to remain at a fixed
maximum setting.
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exchanger loss, and heat exchanger efficiency correlation and the core
engine cycle thermodynamic efficiency are or will be optimized.” Robinson
¶¶ 19, 20; see also Ans. 5.
Templin discloses that “[t]he saving in fuel is very substantial,
particularly from a relative point of view, at light load or idling conditions of
operation of the engine.” Templin, 1:18–21. Thus, Templin, similar to
Robinson, maximizes thermodynamic efficiency at low load for fuel savings.
Appellant’s contention that adding a bypass after the turbine section would
cause Templin to not use the full capacity of its heat exchanger (see Reply
Br. 3) does not apprise us of Examiner error. Templin does not disclose that
the full capacity of the heat exchanger must be used at all times, and
Appellant does not explain why it should not be used less. Nor would
failing to use the full capacity of the heat exchanger “ruin Templin’s
objective.” Reply Br. 5. Templin’s objective is to improve the starting
characteristics of a regenerative gas turbine (see Templin, 1:5–6), and this
functionality is maintained in the Examiner’s proposed modification.
Given that Robinson discloses operating a heat exchanger bypass to
optimize the core engine cycle thermodynamic efficiency, the Examiner’s
proposal to bypass the heat exchanger in Templin to optimize
thermodynamic efficiency provides a benefit because it offers additional
control of Templin’s engine in that both the compressor flow and turbine
exhaust can be controlled.
We have considered all of Appellant’s arguments for the patentability
of claim 12. However, we are not apprised of Examiner error. We therefore
sustain the rejection of claim 12 as unpatentable over Templin and
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Robinson. Appellant does not argue separately for the patentability of
claims 13 and 17 (see Appeal Br. 5) and these claims fall with claim 12.

Rejection II
The Examiner considers that Templin and Robinson do not teach a
controller configured with at least low and high power modes with respect to
back pressure on the turbine section, as recited in claim 14. Nonetheless, the
Examiner finds that Mackay discloses an operating mode in which the
combustion turbine load is reduced by closing valves 402 and 406 and
opening valve 404, and an operating mode where the combustion turbine
load is moderate to high by closing valves 406 and 404 and opening valve
402 to bypass recuperator 202. Final Act. 6. The Examiner concludes that it
would have been obvious to modify Templin to control air to the combustor
during low and high load operating states as taught by Mackay “to provide
increased efficiency and reduced environmental impact during reduced load
operation (Paragraph 41) and to provide reduced nitrous oxide emissions
during high load operation (Paragraph 42).” Id.
Appellant argues that Mackay does not disclose that “operation of the
valve 402 is linked in any way to a ‘high power mode.’” Appeal Br. 6.
Appellant asserts that, moreover, the proposed modification would change
the principle of operation of Templin because reducing nitrous oxide
emissions would “correspondingly reduce the compressor airflow to
Templin’s heat exchanger, thereby providing for less heat recuperation, and
reducing the ‘very great improvement in fuel consumption’ provided by
Templin’s regenerator.” Id. (citing Templin, 1:4–21).
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The Examiner responds that the proposed modification to Templin is
based on control after starting and does not affect Templin’s principle of
operation of improved starting performance. Ans. 6.
In reply, Appellant argues that “the Examiner’s response fails to
address Appellant’s argument.” Reply Br. 4. According to Appellant,
during Templin’s “normal” operation, airflow is beneficially provided to the
heat exchanger, and reducing the airflow “teaches against the proposed
modification.” Id.
We do not agree that the Examiner’s modification changes the
principle of operation of Templin, and we define the the principle as
operating as a regenerator. Nothing in the prior art teaches that the proposed
modification would have resulted in an “inoperable” device. In addition,
Appellant’s arguments regarding possible detrimental effects of reducing the
airflow to the heat exchanger are unavailing. Winner Int’l Royalty Corp. v.
Wang, 202 F.3d 1340, 1349 n.8 (Fed. Cir. 2000) (“The fact that the
motivating benefit comes at the expense of another benefit, however, should
not nullify its use as a basis to modify the disclosure of one reference with
the teachings of another. Instead, the benefits, both lost and gained, should
be weighed against one another.”).
Here, Mackay explicitly discloses that using the heat exchanger when
the load is reduced “provides increased efficiency and reduced
environmental impact through increased waste heat recovery and reduced
carbon monoxide and unburned hydrocarbon emissions,” whereas bypassing
the heat exchanger under high load “provides reduced nitrous oxide (‘NOx’)
emissions.” Mackay ¶¶ 41–42; see also Final Act. 6. Mackay’s disclosure
is consistent with Templin, which discloses very substantial fuel saving “at
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light load or idling conditions of operation of the engine.” Templin, 1:18–
21. On balance, the alleged negative effects of the Examiner’s proposed
combination, which occurs at high loads, whereas Templin discloses fuel
saving “at light load,” do not outweigh the proposed benefit of providing
increased efficiency and reduced environmental impact during reduced load
operation, and reduced nitrous oxide emissions during high load operation.
Appellant’s argument that Mackay does not operate in a “high power
mode” are unavailing. Appellant’s Specification discloses that the term
“power mode” relates to back pressure and that in the high power mode, the
diverter valve is closed to bypass the heat exchanger. Spec. ¶¶ 46, 48.
Similarly, in Mackay’s operating mode for high turbine load, the flow
bypasses the recuperator 202 (heat exchanger). Mackay ¶¶ 20, 42.
Although Mackay does not use the same terminology as Appellant, the
operating modes are the same.
We sustain the Examiner’s rejection of claim 14 as unpatentable over
Templin, Robinson, and Mackay.

Rejection III
Claim 26 depends from claim 12. Appellant does not argue separately
for the patentability of claim 26. See Appeal Br. 6. For the same reasons
discussed for claim 12, we sustain the rejection of claim 26 as unpatentable
over Templin, Robinson, and Merchant.
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CONCLUSION
In summary:
Claims
Rejected
35 U.S.C. § Basis Affirmed Reversed
12, 13, 17 103 Templin, Robinson 12,13, 17
14 103 Templin, Robinson,
Mackay
14
26 103 Templin, Robinson,
Merchant
26
Overall
Outcome
12–14, 17,
26

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