Jeffery F. Perlak et al.

Patent Trials and Appeals Board

Feb 12, 2020

14789036 - (D) (P.T.A.B. Feb. 12, 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.
14/789,036 07/01/2015 Jeffery F. Perlak 81817US1;
67097-3238PUS1
1004
54549 7590 02/12/2020
CARLSON, GASKEY & OLDS/PRATT & WHITNEY
400 West Maple Road
Suite 350
Birmingham, MI 48009
EXAMINER
MCGLYNN, JAMES P
ART UNIT PAPER NUMBER
3741
NOTIFICATION DATE DELIVERY MODE
02/12/2020 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):
ptodocket@cgolaw.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte JEFFERY F. PERLAK, JOSEPH B. STAUBACH,
GABRIEL L. SUCIU, JAMES D. HILL, and FREDERICK M. SCHWARZ
Appeal 2018-007729
Application 14/789,036
Technology Center 3700
BEFORE DANIEL S. SONG, JILL D. HILL, and
RICHARD H. MARSCHALL, Administrative Patent Judges.
HILL, 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 1–14, 16, 17, and 19–22. We have
jurisdiction under 35 U.S.C. § 6(b).
We AFFIRM IN PART.

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 the assignee
UNITED TECHNOLOGIES CORPORATION. Appeal Br. 1.
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BACKGROUND
Sole independent claim 1, reproduced below with certain limitations
italicized, represents the claimed subject matter:
1. A gas turbine engine, comprising:
a first compressor and a first turbine for driving the first
compressor;
a core section including a second compressor and a second
turbine for driving the second compressor;
a third turbine arranged fluidly downstream of the first
turbine and the second turbine and configured to drive a power
take-off; and
a first duct system arranged fluidly between the first
compressor and the core section, the first duct system arranged
to reverse fluid flow before entry into the core section, wherein
the first compressor is configured to receive a working fluid
flowing in an axially aft direction, the second compressor is
configured to receive the working fluid flowing in an axially
forward direction opposite the axially aft direction, and the first
compressor is directly joined to the first duct system.

REFERENCES
The prior art relied upon by the Examiner is:
Name Reference Date
Constant US 2,504,181 April 18, 1950
Shohet US 3,678,690 July 25, 1972
Buchelt US 3,738,105 June 12, 1973
Nakamura US 8,641,371 B2 February 4, 2014
Donnelly US 2014/0306460 A1 October 16, 2014
Norris US 8,935,912 B2 January 20, 2015
Schmittenberg US 9,500,129 B2 November 22, 2016
Gunston, B. (2000). Jane’s aero-engines. Alexandria (VA): Jane’s
Information Group, 3–8, 61.

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REJECTIONS
I. Claims 1–4, 6–9, 11, 12, 14, 19, and 20 stand rejected under 35
U.S.C. § 103(a) as unpatentable over Norris and Donnelly. Final Act. 2.
II. Claim 17 stands rejected under 35 U.S.C. § 103(a) as
unpatentable over Norris, Donnelly, and Gunston. Final Act. 6.
III. Claim 1 stands rejected under 35 U.S.C. § 103(a) as
unpatentable over Norris and Shohet. Final Act. 7.
IV. Claims 5, 10, and 16 stand rejected under 35 U.S.C. § 103(a) as
unpatentable over Norris, Shohet, Nakamura, and Buchelt. Final Act. 8.
V. Claim 13 stands rejected under 35 U.S.C. § 103(a) as
unpatentable over Norris, Shohet, Nakamura, Buchelt, and Schmittenberg.
Final Act. 9.
VI. Claims 21 and 22 stand rejected under 35 U.S.C. § 103(a) as
unpatentable over Norris, Shohet, Nakamura, Buchelt, and Constant. Final
Act. 10.
ANALYSIS
For each of Rejections I through VI, Appellant challenges the
Examiner’s conclusions of obviousness, rather than any factual findings.
We address Appellant’s arguments below.
Rejection I – Claims 1–4, 6–9, 11, 12, 14, 19, and 20
Appellant argues claims 1–4, 6–9, 11, 12, 14, 19, and 20 as a group.
We select independent claim 1 as representative. Claims 2–4, 6–9, 11, 12,
14, 19, and 20 stand or fall with claim 1.
Regarding independent claim 1, the Examiner finds, inter alia, that
Norris discloses a gas turbine engine with a first compressor 106, a first
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turbine 110 for driving the first compressor 106, a core section including a
second compressor 130 and a second turbine 126 for driving the second
compressor 130, and a third turbine 120 downstream of the first and second
turbines 110, 126. Final Act. 3. A first duct system 170 extends between
the first compressor 106 and the core section 126, 130, and reverses fluid
flow direction. Id. The Examiner finds that Norris does not disclose its
third turbine being configured to drive a power take-off, but Donnelly
discloses a similarly-configured gas turbine engine having a third turbine
configured to drive a power take-off (i.e., an electrical generator 64), and
concludes that it would have been obvious to have Norris’s third turbine 120
drive a power take-off as in Donnelly to provide “power output in the range
of about 1 kW to about 10 kW,” which “could obviously power avionics or
engine control systems in an aircraft.” Id. at 3–4; see Donnelly ¶ 73.
The embodiment of Norris’ Figure 2 discloses, inter alia, a gas
turbine engine 100 having a low pressure spool 102, an intermediate
pressure spool 111, and a high pressure spool 122. Norris 6:14–37. The low
pressure spool includes an intermediate pressure turbine 110 on a first shaft
104 coupled to a fan 106. Norris 6:14–20. One or more generators 121 can
be “operatively coupled to” the low pressure spool 102 to share power
therewith during portions of the flight envelope. Norris 6:23–25. The
intermediate pressure spool 111 has an intermediate compressor 118 and a
low pressure turbine 120 coupled to a second shaft 114. Norris 6:26–33. A
fan 116 is coupled to shaft 114. Id. The high pressure spool 122 includes a
high pressure turbine 126 and a high pressure compressor 130. Norris 6:36–
43. A primary shaft 140 is coupled to the high pressure turbine 126 and the
high pressure compressor 130. Norris 6:57–60.
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Donnelly discloses, as prior art illustrated in Figure 1, a gas turbine
engine architecture having a gas inlet 51, a combustor 59, an exhaust 66, and
three spools: a high pressure turbo compressor spool 53; a low pressure
turbo compressor spool 5; and a free power turbine spool 54. Donnelly ¶ 70.
The high and low pressure spools 53, 52 each include a compressor 57, 55
and a turbine 60, 61, respectively, connected by a shaft. Id. The free power
turbine spool 54 includes a turbine 63 and a load device 64 that can be a
motor/generator capable of high power operation. Id. A prior art shaft 3
that would be used in the gas turbine engine architecture of Donnelly’s
Figure 1 is shown in Donnelly’s Figure 2. See Donnelly ¶ 71. On one end
of the shaft is a compressor rotor 1, and on the other end of the shaft is a
turbine rotor 68. Id. This assembly is stated to be “typical of a high-
pressure spool.” Id.
Donnelly discloses adding copper cladding and a stator to a prior art
turbo-compressor assembly, which would allow rotation of the turbo-
compressor shaft to generate electrical power. See Donnelly ¶ 76. The
embodiment of Donnelly’s Figure 9 adds copper cladding to a turbo-
compressor shaft 3, which cooperates with a surrounding rotor to generate
electricity. See Donnelly Figure 9, ¶¶ 97–98.
Frustrate Intended Purpose
Appellant argues that the Examiner’s conclusion of obviousness is in
error because having Norris’ third turbine 120 drive a power take-off as in
Donnelly would frustrate the intended purpose of Norris. Appeal Br. 5.
According to Appellant, if Norris’s low pressure (third) turbine 120 was
modified to drive a power take-off, as the Examiner is proposing, it would
result in providing less power to the intermediate pressure compressor 118,
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“undesirably reducing the [overall pressure ratio (‘OPR’)] of Norris’s
engine.” Id. at 6. Appellant contends that “Norris’s low pressure turbine
120 already drives its second shaft 114 coupled to the second fan 116 and
intermediate pressure compressor 118,” and a skilled artisan “would realize
that adding any load to this turbine, and especially the significant load
disclosed in Donnelly, would necessarily result in the spool being driven
more slowly than without the load,” resulting in “less compression by the
intermediate compressor 118,” leading to “a reduced OPR (the overall
compression of the engine), which would be directly counter to Norris’s
stated purpose.” Id. at 6–7 (emphasis omitted). Appellant appears to define
Norris’s intended purpose as achieving a high OPR during certain aircraft
modes. Appeal Br. 5–6 (citing Norris, 1:13–25, 3:66–67, 4:13–21, 8:10–
33).
The Examiner responds that “the stated purpose of Norris is not to
achieve a maximum [OPR], but rather to achieve a variable [OPR], for
optimization in various modes of flight.” Ans. 4 (citing Norris Abstract,
4:18–21). According to the Examiner, configuring Norris’s third turbine
120 to drive a power take-off would not have frustrated Norris’s intended
purpose, because Norris’s engine “could have achieved a variable [OPR]
using selectively engaged stages of the high pressure compressor, in addition
to driving a power take-off with the third turbine.” Id. The Examiner
continues that “[m]any components in modern aircraft require electricity to
operate,” and “[u]sing the third turbine to drive a generator, i.e. a power
take-off, could [provide] electricity to these various components.” Id.
Furthermore, the Examiner proposes using Norris’s third turbine 120 to
drive a generator in addition to the compressor, in view of Donnelly’s Figure
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9, which discloses successfully driving both a compressor and a power take-
off.
The Examiner has the better argument. The claim only requires that
the third turbine be configured to drive a power take-off. No particular load
requirement is recited. Further, a skilled artisan would understand the
tradeoff between decreasing power to an associated compressor and
beneficially providing power from the take-off, and could select an
appropriate compromise to achieve desirable results. We, thus, agree with
the Examiner that a skilled artisan would understand how to modify Norris’s
engine to achieve a variable overall pressure ratio using selectively engaged
stages of the high pressure compressor, in addition to driving a power take-
off with the third turbine. Ans. 4.
Reasonable Expectation of Success
Appellant next argues that “there would be no reasonable expectation
of success in using Norris’s low pressure turbine 120 to drive a power take-
off,” because Donnelly’s free power spool turbine 63 only powers a load
device 64, which is distinguished from Donnelly’s other spools 52 and 53
that power compressors 55, 57, and may also power other smaller loads 65.
Appeal Br. 7. According to Appellant, the Examiner appears to be
proposing that Norris’s low pressure turbine 120 drive a power take-off in
addition to components it already drives, based on the teachings of
Donnelly, but a skilled artisan would not understand Donnelly to teach “that
a third turbine could power both a compressor and a high power load.” Id.
Appellant contends that Donnelly assigns its high power load to its spool 54
lacking a compressor, while assigning smaller loads 65 to its compressor-
driving spools 52 and 53. Id. (citing Donnelly ¶ 70 (“Two are nested turbo-
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compressor spools and one is a free power turbine spool connected to a load
device.”)). Appellant further contends that Norris’s low pressure turbine
120 already drives its shaft 114, second fan 116, and intermediate pressure
compressor 118, such that there is no expectation of success in combining
teachings from Donnelly’s free spool with Norris’s compressor-driving
spool, especially where Donnelly distinguishes the two. Id. at 8 (citing
Norris, 6:26–35, Figure 2).
We are not persuaded by Appellant’s argument. As explained above,
the embodiment of Donnelly’s Figure 9 adds copper cladding to a turbo-
compressor shaft 3, which cooperates with a surrounding rotor to generate
electricity (Donnelly Figure 9, ¶¶ 97–98), such that a skilled artisan would
have had reasonable expectation of success in view of Donnelly’s teaching
of a third turbine at 68 powering both a compressor at 67 and a high power
load at 6.
For these above reasons, we sustain the rejection of independent claim
1. Claims 2–4, 6–9, 11, 12, 14, 19, and 20 fall with claim 1.
Rejection II – Claim 17
Claim 17 depends from claim 1. Appellant makes no argument that
claim 17 is patentable over Norris, Donnelly, and Gunston, even if claim 1 is
not patentable over Norris and Donnelly. We sustain Rejection II for the
reasons set forth above regarding claim 1.

Rejection III – Claim 1
The Examiner again finds that Norris discloses the claimed invention,
except that Norris’s low pressure turbine 120 is not disclosed as configured
to drive a power take-off. Final Act. 7. The Examiner finds, however, that
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Shohet discloses a third turbine 46 downstream from a first turbine 38, and a
second turbine 44, the third turbine 46 being configured to drive a power
takeoff 74. Id. at 8. The Examiner concludes that it would have been
obvious to modify Norris’s gas turbine to include a third turbine, fluidly
downstream of the first and second turbines, which is “configured to drive a
power takeoff, as taught by Shohet, to facilitate driving a helicopter rotor
driveshaft.” Id. (citing Shohet 3:54–58).
Appellant contends that Shohet refers to its turbine 46 as a “free
turbine” having the sole job of being the shaft horsepower generating free
turbine. Appeal Br. 8–9 (citing Shohet, 3:27–65, Figure 1). According to
Appellant, “[u]nlike Shohet’s [first] turbine 38 that is coupled to its
compressor 34, Shohet’s [third] turbine 46 is a free turbine operating solely
to drive a helicopter rotor.” Id. at 9 (citing Shohet, 3:27–65, Figure 1)
(emphasis omitted).
Norris’s disclosure is explained above. Shohet discloses a convertible
composite engine with a three coaxial turbines: turbine 38 that drives
compressor 34; turbine 44 that drives fan 16; and turbine 46 that is a shaft
horsepower generator driving, e.g. a helicopter rotor. Shohet 3:15–52.
Shohet discloses its turbine 46 as driving “shaft horsepower take-off means
74, which is typically operatively connected in conventional fashion to drive
helicopter rotor drive shaft 78 and hence helicopter rotor 76.” Shohet 3:55–
58.
Appellant argues that the Examiner’s conclusion of obviousness is in
error because Shohet “teaches a separate turbine that powers a significant
load – a helicopter rotor,” and “[m]odifying Norris’s third turbine to power a
power take-off in view of Shohet’s teachings would necessarily reduce its
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OPR, directly contrary to [Norris’s] intended purpose.” Appeal Br. 9 (citing
Shohet 3:27–65, Figure 1) (emphasis omitted)).
Appellant also argues that “there would be no reasonable expectation
of success in using Norris’s low pressure turbine 120 to drive a power take-
off,” because Norris’s low pressure turbine 120 already drives its shaft 114,
second fan 116, and intermediate pressure compressor 118. Appeal Br. 9
(citing Norris, 6:26–35, Figure 2). Specifically, Shohet discloses a free
turbine 46 with the sole purpose of generating shaft horsepower to power a
helicopter rotor. Id. at 9–10 (citing Shohet 3:27–65, Figure 1). Shohet
describes its turbine 46 as a shaft horsepower generating free turbine, rather
than a turbine (e.g., turbine 38) that drives a compressor (e.g., a compressor
34). Id. at 10 (citing Shohet 3:22–23, 3:52). According to the Appellant,
because Shohet discloses one turbine 38 that drives a compressor and a
separate turbine 46 that drives a take-off, Shohet’s disclosure “does not
provide a reasonable expectation of success that Norris’s low pressure
turbine 120 could drive a power take off in addition to driving its second fan
116 and intermediate pressure compressor 118.” Id. (emphasis omitted).
Appellant contends that “designating a free turbine to solely power a take-
off does not teach that a turbine could power both a compressor and a take-
off.” Id.
We agree with Appellant that the Examiner has not established a
rational basis for the proffered reasoning. The Examiner’s assertion that
Norris’s third (low pressure) turbine 120, which drives Norris’s fan 116 and
compressor 118, could also power a helicopter rotor is speculative and
appears unreasonable. If the Examiner is proposing to replace Norris’s
driven fan 116 and/or compressor 118 with Shohet’s rotor, or otherwise
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eliminate such components such that the third turbine 120 of Norris becomes
a shaft horsepower generator, the Examiner has not explained in sufficient
detail how a skilled artisan would understand Norris to be able to
accomplish its intended purpose. For this reason we do not sustain Rejection
III.
Rejection IV – Claims 5, 10, and 16
Claims 5, 10, and 16 ultimately depend from claim 1. The Examiner
makes no finding that either Nakamura or Buchelt provide a reason to
combine Norris and Shohet to result in the invention claimed. We do not
sustain Rejection IV for the reasons set forth above regarding Rejection III.
Rejection V – Claim 13
Claim 13 ultimately depends from claim 1. The Examiner makes no
finding that Nakamura, Buchelt, or Schmittenberg provide a reason to
combine Norris and Shohet to result in the invention claimed. We do not
sustain Rejection V for the reasons set forth above regarding Rejection III.

Rejection VI – Claims 21 and 22
Claim 21 ultimately depends from claim 1. The Examiner makes no
finding that either Nakamura or Buchelt provide a reason to combine Norris
and Shohet to result in the invention claimed. We do not sustain Rejection
VI for the reasons set forth above regarding Rejection III.

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DECISION SUMMARY
In summary:
Claims
Rejected
35 U.S.C. § Reference(s)/Basis Affirmed Reversed
1–4, 6–9,
11, 12, 14,
19, 20
103 Norris, Donnelly 1–4, 6–9, 11,
12, 14, 19, 20

17 103 Norris, Donnelly,
Gunston
17
1 Norris, Shohet 1
5, 10, 16 103 Norris, Shohet,
Nakamura, Buchelt
5, 10, 16
13 103 Norris, Shohet,
Nakamura,
Buchelt,
Schmittenberg
13
21, 22 103 Norris, Shohet,
Nakamura,
Buchelt, Constant
21, 22
Overall
Outcome
1–4, 6–9, 11,
12, 14, 17,
19, 20
5, 10, 13,
16, 21, 22

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-IN-PART