Peter G. Smith et al.

Patent Trials and Appeals Board

Sep 30, 2019

13346100 - (D) (P.T.A.B. Sep. 30, 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.
13/346,100 01/09/2012 Peter G. Smith 50562US03;67097-857PUS3 8414
54549 7590 09/30/2019
CARLSON, GASKEY & OLDS/PRATT & WHITNEY
400 West Maple Road
Suite 350
Birmingham, MI 48009
EXAMINER
MEADE, LORNE EDWARD
ART UNIT PAPER NUMBER
3741
NOTIFICATION DATE DELIVERY MODE
09/30/2019 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 PETER G. SMITH, STUART S. OCHS, and
FREDERICK M. SCHWARZ
____________

Appeal 2017-010042
Application 13/346,100
Technology Center 3700
____________

Before JEREMY M. PLENZLER, GEORGE R. HOSKINS, and
PAUL J. KORNICZKY, Administrative Patent Judges.

HOSKINS, Administrative Patent Judge.

DECISION ON APPEAL

STATEMENT OF THE CASE
Appellant1 appeals under 35 U.S.C. § 134 from the Examiner’s
decision rejecting claims 1, 3–10, 14, 15, and 17 in this application. The
Board has jurisdiction over the appeal 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. 1 (dated Dec. 5, 2016).
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CLAIMED SUBJECT MATTER
Claim 1 is the sole independent claim on appeal. Claims 1, 14, 15,
and 17 are reproduced below. See Claims App. 2–4 (dated Jan. 4, 2017).
1. A gas turbine engine comprising:
a core engine disposed about an engine centerline axis,
the core engine including a first spool and a second spool,
the first spool including a first compressor and a first turbine
and the second spool including a second compressor and a
second turbine;
a core nacelle defined about the core engine;
a fan section disposed forward of the core engine;
a fan nacelle mounted at least partially around said core
nacelle to define a fan bypass flow path for a fan bypass
airflow;
a fan variable area nozzle movable relative said fan
nacelle to vary a fan nozzle exit area and adjust a pressure
ratio of the fan bypass airflow during engine operation;
a multiple of fan exit guide vanes in communication
with said fan bypass flow path, said multiple of fan exit
guide vanes rotatable about an axis of rotation to vary said
fan bypass flow path, wherein the axis of rotation for each
of the multiple fan exit guide vanes is located about a
geometric center of gravity of a cross-section of the fan exit
guide vane taken parallel to the engine centerline axis; and
a gear system driven by the core engine to drive a fan
within said fan nacelle at a speed different than both the first
compressor and the second compressor, said gear system
defines a gear reduction ratio of greater than or equal to 2.5.
14. The engine as recited in claim 1, wherein said core engine
includes a low pressure turbine which defines a pressure
ratio that is greater than five (5).
15. The engine as recited in claim 1, wherein said bypass flow
defines a bypass ratio greater than six (6).
17. The engine as recited in claim 1, wherein said bypass flow
defines a bypass ratio greater than ten (10).
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REJECTIONS ON APPEAL
Claims 1, 3–10, 14, 15, and 17 stand rejected under 35 U.S.C. § 112,
first paragraph,2 for lack of written description.3
Claims 1, 3–10, 14, 15, and 17 stand rejected under 35 U.S.C. § 112,
first paragraph, for lack of enablement.
Claims 1, 3–10, 14, 15, and 17 stand rejected under 35 U.S.C. § 112,
second paragraph, as indefinite.
Claims 5 and 6 stand rejected under 35 U.S.C. § 112, fourth
paragraph, as being of improper dependent form.
Claims 1, 3, 4, 7, and 10 stand rejected under 35 U.S.C. § 103(a) as
unpatentable over Coplin (US 4,827,712, iss. May 9, 1989), Gisslen
(US 3,892,358, iss. July 1, 1975), Neitzel (US 4,791,783, iss. Dec. 20,
1988), Suljak (US 2009/0067978 A1, pub. Mar. 12, 2009), and Dunbar ’187
(US 5,259,187, iss. Nov. 9, 1993).
Claims 5 and 6 stand rejected under 35 U.S.C. § 103(a) as
unpatentable over Coplin, Gisslen, Neitzel, Suljak, Dunbar ’187,
Dunbar ’763 (US 6,292,763 B1, iss. Sept. 18, 2001), and Ferri
(US 2,805,818, iss. Sept. 10, 1957).
Claims 8 and 9 stand rejected under 35 U.S.C. § 103(a) as
unpatentable over Coplin, Gisslen, Neitzel, Suljak, Dunbar ’187, and Rauch
(D. Rauch, Design Study of an Air Pump and Integral Lift Engine ALF-504

2 The application on appeal was filed on January 9, 2012, before the AIA
amendments to § 112 took effect on September 16, 2012. See Leahy-Smith
America Invents Act (“the AIA”), Pub. L. No. 112–29, § 4(e), 125 Stat. 284,
297 (2011); MPEP § 2161(I).
3 The Examiner has withdrawn some aspects of the written description
rejection. See Ans. 2 (withdrawing Final Act. ¶¶ 4, 5).
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Using the Lycoming 502 Core, NASA Report CR-120,992, NASA Lewis
Research Center, Cleveland, Ohio, July 1972).
Claim 14 stands rejected under 35 U.S.C. § 103(a) as unpatentable
over Coplin, Gisslen, Neitzel, Suljak, Dunbar ’187, and Boggia (S. Boggia
& K. Rüd, lntercooled Recuperated Gas Turbine Engine Concept,
AIAA 2005–4192, 41st AIAA/ASME/SAE/ASEE Joint Propulsion
Conference & Exhibit, Tucson, Arizona, July 10–13, 2005).
Claims 15 and 17 stand rejected under 35 U.S.C. § 103(a) as
unpatentable over Coplin, Gisslen, Neitzel, Suljak, Dunbar ’187, and Jane’s
Aero-Engines (Jane’s Aero-Engines, Issue Seven, ed. Bill Gunston, Jane’s
Information Group Inc., Alexandria, Virginia, 2000).
OPINION
A. Written Description (Claims 1, 3–10, 14, 15, and 17)
The test for sufficiency of a written description under 35 U.S.C. § 112
¶ 1 is whether an application’s disclosure “reasonably conveys to those
skilled in the art that the inventor had possession of the claimed subject
matter as of the filing date.” Ariad Pharms., Inc. v. Eli Lilly & Co., 598 F.3d
1336, 1351 (Fed. Cir. 2010) (en banc). This “requires an objective inquiry
into the four corners of the specification from the perspective of a person of
ordinary skill in the art.” Id. Written description and enablement are
separate requirements of 35 U.S.C. § 112 ¶ 1, requiring different analyses.
Ariad, 598 F.3d at 1342–54.
Claim 1
The Examiner determines Appellant’s Specification fails to
demonstrate possession of a “gear system defin[ing] a gear reduction ratio of
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greater than or equal to 2.5,” as recited in claim 1. Final Act. 4–7 (emphasis
by Examiner), 44–45. The Examiner acknowledges the Specification’s
disclosure that “the gear system may define a gear reduction ratio of greater
than or equal to 2.5” (Spec. ¶¶ 10, 29), but dismisses the disclosure as
“merely repeat[ing]” the claim language. Final Act. 5.
The Examiner relies on MPEP § 2163.03(V), which provides that
“[a]n original claim may lack written description support when . . . the claim
defines the invention in functional language specifying a desired result but
the disclosure fails to sufficiently identify how the function is performed or
the result is achieved.” Final Act. 5 (emphases by Examiner). The
Examiner determines the challenged subject matter in claim 1
correspondingly recites “functional language specifying a desired result, i.e.,
gear reduction ratio of greater than 2.5,” and Appellant’s Specification does
not sufficiently specify structure(s) for achieving that result. Id. at 5, 44–45;
Ans. 4–5.
The Examiner also finds Pratt & Whitney (a division of the real party
in interest, United Technologies Corporation (see Coy4, 3)) took seven years
and spent several hundreds of millions of dollars to increase the 2.8125 gear
reduction ratio in the PW8000 engine to 3.0 in the GTF engine, despite that
other engines were already known to have gear reduction ratios of between
2.3 and 3.73. Final Act. 6–7 (citing Rauch, 1, 6, 36; Jane’s Aero-Engines,
510–512; Warwick5, 1–2). Based on that finding, the Examiner concludes a

4 P. Coy, The Little Gear That Could Reshape the Jet Engine, Bloomberg
Business, Oct. 15, 2015.
5 G. Warwick, Civil Engines: Pratt & Whitney gears up for the future with
GTF, Flight, Nov. 2007.
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person of ordinary skill in the art “would not have recognized that
[Appellant was] in possession of the invention as claimed, i.e., gear
reduction ratios ranging from 4.0 to 25, 50, 100, . . . , 2000 and greater.” Id.
Appellant relies on paragraph 29 of the Specification as demonstrating
possession of a gear system defining a gear reduction ratio of greater than or
equal to 2.5. Appeal Br. 3. Appellant asserts the Examiner errs in requiring
the Specification to demonstrate possession of gear reduction ratios
“reach[ing] to infinity,” because the law does not require Appellant to
“demonstrate possession of theoretical and unachievable numerical values,”
even though claim 1 does not specify an upper limit for the gear reduction
ratio. Id. at 4. Appellant contends a person of ordinary skill in the art would
have known “inherent limitations exist” in achievable gear reduction ratios.
Id.
The Examiner answers that Appellant’s arguments are “just attorney
argument,” “without factual support in” the evidence of record including
Appellant’s Specification. Ans. 5–7. According to the Examiner,
Appellant’s claimed gear reduction ratio does “not have an inherent upper
limit because [ratio] values changed over time as technology advanced.” Id.
at 5–6 (emphases by Examiner).
The issue here is written description, not enablement. The enablement
requirement is discussed below. Written description requires only that the
Specification demonstrates Appellant had possession of the claimed
invention at the time the application was filed. See Ariad, 598 F.3d at 1351.
That requirement is met here. Appellant’s Specification demonstrates the
invention encompasses a gas turbine engine having a gear reduction ratio of
greater than or equal to 2.5. Spec. ¶¶ 10, 29. Nothing more is required. The
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MPEP section cited by the Examiner concerns the discussion in Ariad
relating to “a generic claim [that defines] the boundaries of a vast genus of
chemical compounds,” and whether “the applicant has invented species
sufficient to support a claim to a genus.” Ariad, 598 F.3d at 1349; MPEP
§ 2163.03(V). Such concerns do not apply here, where the challenged
subject matter is a reduction ratio achieved by, for example, an epicycle gear
train such as a planetary gear system. Spec. ¶ 29. The Examiner does not
explain why such a gear system could not achieve a reduction ratio that
greatly exceeds 2.5. See Final Act. 5, 44–45; Ans. 4–5. Therefore, we do
not sustain the written description rejection of claim 1.
Claims 3–10
Claims 3–10 are rejected for lack of written description based solely
on the challenged subject matter of their common parent claim 1. See Final
Act. 4–11. For the reasons provided above in connection with claim 1, we
do not sustain the written description rejection of claims 3–10.
Claim 14
The Examiner determines Appellant’s Specification fails to
demonstrate possession of “a low pressure turbine which defines a pressure
ratio that is greater than five (5),” as recited in claim 14. Final Act. 7–9
(emphasis by Examiner), 44–45. The Examiner’s reasoning in support of
this rejection is substantially the same as the rejection of claim 1, re-cast to
the low pressure turbine pressure ratio subject matter at issue here. See id.;
Ans. 3–7. Appellant’s response is likewise substantially the same. See
Appeal Br. 4–5.
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The issue here is written description, not enablement. The enablement
requirement is discussed below. Appellant’s Specification demonstrates the
invention encompasses a low pressure turbine pressure ratio of greater than
five (5). Spec. ¶¶ 11, 12, 29. Nothing more is required. The challenged
subject matter is a pressure ratio achieved by a low pressure turbine. Spec.
¶¶ 28–30, Fig. 1A. The Examiner does not explain why a low pressure
turbine could not achieve a pressure ratio that greatly exceeds five (5). See
Final Act. 7–8, 44–45; Ans. 4–5. Therefore, we do not sustain the written
description rejection of claim 14.
Claims 15 and 17
The Examiner determines Appellant’s Specification fails to
demonstrate possession of “a bypass ratio greater than six (6)” as recited in
claim 15 or “greater than ten (10)” as recited in claim 17. Final Act. 9–11
(emphases by Examiner), 44–45. The Examiner’s reasoning in support of
this rejection is substantially the same as the rejection of claim 1, re-cast to
the bypass ratio subject matter at issue here. See id.; Ans. 3–7. Appellant’s
response is likewise substantially the same. See Appeal Br. 4–5.
The issue here is written description, not enablement. The enablement
requirement is discussed below. Appellant’s Specification demonstrates the
invention encompasses a bypass ratio of greater than “about six (6),” or
more narrowly of greater than 10. Spec. ¶¶ 13, 29. Nothing more is
required, at least regarding the upper end of the claimed range, which is the
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basis for the Examiner’s rejection.6 The challenged subject matter is a
bypass ratio achieved by the geometrical configuration of a gas turbine
engine splitting an incoming airflow into a bypass flow path and a core flow
path. Spec. ¶¶ 5, 13, 29, 31, 34, 37, Fig. 1A. The Examiner does not
explain why such an engine geometry could not achieve a bypass ratio that
greatly exceeds six (6) or ten (10). See Final Act. 9–11, 44–45; Ans. 4–5.
Therefore, we do not sustain the written description rejection of claims 15
and 17.
B. Enablement (Claims 1, 3–10, 14, 15, and 17)
A specification is not enabling if a person of ordinary skill in the art
would require “undue experimentation” to practice the claimed invention.
In re Wands, 858 F.2d 731, 736–37 (Fed. Cir. 1988). “Enablement is not
precluded by the necessity for some experimentation.” Id. (emphasis
added); see also Enzo Biochem, Inc. v. Calgene Inc., 188 F.3d 1362, 1371
(Fed. Cir. 1999) (enablement is not negated if a reasonable amount of
experimentation is required to practice the claimed invention). Whether
undue experimentation would be necessary is not a single, simple factual
determination, but rather is a conclusion reached by weighing many factual
considerations, such as: (1) the quantity of experimentation necessary,
(2) the amount of direction or guidance presented, (3) the presence or
absence of working examples, (4) the nature of the invention, (5) the state of
the prior art, (6) the relative skill of those in the art, (7) the predictability or
unpredictability of the art, and (8) the breadth of the claims. Wands,

6 The difference between “greater than about six (6)” in Appellant’s
Specification (emphasis added), and “greater than six (6)” in claim 15, is not
at issue in the rejection on appeal.
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858 F.2d at 736–37. “A patent need not disclose what is well known in the
art.” Id. at 735.
The Examiner and Appellant agree that the decision in Scripps Clinic
& Research Found. v. Genetech, Inc., 927 F.2d 1565 (Fed. Cir. 1991),
overruled on other grounds, Abbott Labs. v. Sandoz, Inc., 566 F.3d 1282,
1291–92 (Fed. Cir. 2009) (en banc), pertains to the enablement of an
open-ended range of values, such as recited in the claims at issue here. See
Final Act. 22–24, 46 (also citing Andersen Corp. v. Fiber Composites, LLC,
474 F.3d 1361, 1376–77 (Fed. Cir. 2007)); Appeal Br. 5–6. In Scripps, the
court stated “[o]pen-ended claims are not inherently improper; as for all
claims their appropriateness depends on the particular facts of the invention,
the disclosure, and the prior art.” Scripps, 927 F.2d at 1572. Further, such
claims “may be supported if there is an inherent, albeit not precisely known,
upper limit and the specification enables one of skill in the art to approach
that limit.” Id. (citing In re Fisher, 427 F.2d 833, 839 (CCPA 1970)).
Claim 1
The Examiner determines Appellant’s Specification does not enable a
gas turbine engine comprising a gear reduction ratio of greater than or equal
to 2.5, as recited in claim 1, because the recited range “is not bounded at its
upper limit and therefore includes gear reduction ratios ranging from 2.5 to
25, 50, 100, . . . , 2000 and greater.” Final Act. 12. The Examiner notes
“the scope of the claims must bear a reasonable correlation to the scope of
enablement provided by the specification to persons of ordinary skill in the
art.” Id. at 13–14, 21–22 (emphasis omitted) (quoting Fisher, 427 F.2d at
839). The Examiner also determines Appellant “cannot rely on the
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knowledge of one skilled in the art to supply information that is required to
enable the novel aspect of the claimed invention when the enabling
knowledge is in fact not known in the art.” Id. at 16–17 (citing ALZA Corp.
v. Andrx Pharms., LLC, 603 F.3d 935, 941 (Fed. Cir. 2010); MPEP
§ 2161.0(III)). The Examiner, further, provides an analysis of the Wands
factors. Id. at 17–18.
The Examiner finds Pratt & Whitney took 20–30 years and spent
several hundreds of millions of dollars to increase the 2.8125 gear reduction
ratio in the PW8000 engine to 3.0 in the GTF engine, despite that other
engines were already known to have gear reduction ratios of between 2.3
and 3.73. Final Act. 14–16, 18 (citing Rauch, 1, 6, 36; Jane’s Aero-Engines,
510–512; Warwick; Coy).
Applying the Scripps decision, supra, the Examiner finds the gear
reduction ratio at issue here does “not have an inherent upper limit,” because
it is an engineering design variable, unlike the blood protein purity
percentage at issue in Scripps which had an inherent upper limit of 100%.
Final Act. 23–24 (emphasis by Examiner), 49–50. The Examiner takes
official notice that, as technology has advanced and will continue to advance
over time, stronger and lighter materials will be created, thus increasing
achievable gear reduction ratios. Id. at 50–51; Ans. 16–17. The Examiner
further determines Appellant’s Specification fails to enable a person of
ordinary skill in the art to approach any sort of limit, because it does not
describe any details of a gear reduction structure to achieve an unbounded
limit. Final Act. 24, 46–49.
Appellant argues a person of ordinary skill in the art would know that
a gear reduction ratio has “a practical upper limit that is far short from
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infinity,” based on constraints imposed for a feasibly working gas turbine
engine. Appeal Br. 5–8. For example, according to Appellant, the fan must
turn with enough speed to deliver air to the engine core to power the engine,
and to deliver air to the bypass flow path to provide thrust, yet at the same
time “the fan must turn at a speed within practical, physical limits, making
an infinite gear ratio impractical.” Id. at 8. Appellant additionally asserts
the “Examiner’s own research” demonstrates that gas turbine engine
advances “occur in small predictable increments over a long period of time,”
and “that the gas turbine engine art is mature.” Id. at 7.
The Examiner replies that Appellant’s Specification “failed to disclose
any space limitations, material limitations, weight limitations, operational
limitations, etcetera,” and Appellant has “failed to explain how one of
ordinary skill in the art could determine the alleged practical upper limits of
the gear reduction ratio.” Final Act. 49–50, 57; Ans. 8–11, 15–16, 28–32.
Upon consideration of the foregoing, we note first that the subject
matter at issue (Wands factor (4)) is a gear system having “a gear reduction
ratio of greater than or equal to 2.5.” Claims App. 2. The gear system is
placed between a turbine-compressor spool and a fan, so that energy
extracted from an airflow by the turbine can power the fan, at a lesser
rotational speed than the turbine-compressor spool. Id.; Spec. ¶¶ 5, 28–30,
Fig. 1A. Appellant’s Specification indicates an epicycle gear train such as a
planetary gear system may be suitable here. Spec. ¶ 29.
We appreciate that Appellant’s Specification in the foregoing regards
is sparse, and Appellant’s figures are highly schematic (Wands factors
(1)–(3)), thus requiring some amount of experimentation to implement the
claimed invention. Nonetheless, “a patent need not teach, and preferably
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omits, what is well known in the art” (Wands factors (5)–(7)). Hybritech
Inc. v. Monoclonal Antibodies, Inc., 802 F.2d 1367, 1384 (Fed. Cir. 1986)
(citing Lindemann Maschinenfabrik v. American Hoist & Derrick, 730 F.2d
1452, 1463 (Fed. Cir. 1984)). We determine the state of the art of gear
systems was advanced, and gear systems were highly predictable, at the time
of Appellant’s invention (Wands factors (5) and (7)). A person of ordinary
skill in the art would have known how to change the size and configuration
of various gears, such as in a planetary gear system, to achieve a desired
gear reduction ratio (Wands factors (6) and (7)).
As to the breadth of the claims (Wands factor (8)), we determine a
person of ordinary skill in the art would have appreciated that the claimed
gear reduction ratio has an inherent, albeit not precisely known, upper limit.
Scripps, 566 F.3d at 1572. The gear reduction ratio equals the rotational
speed of the turbine-compressor spool, divided by the rotational speed of the
fan. It is therefore mathematically limited by an inherent maximum
rotational speed achievable by the turbine-compressor spool. This inherent
maximal limitation arises from the finitely available airflow to drive spool
rotation, the weight of the spool, the energy extraction work performed by
the turbine, and the air compression work performed by the compressor.
The ratio is, further, limited by an inherent minimum rotational speed of the
fan, which is required to power the engine and fly the aircraft.
The Examiner cites two cases holding that claims were not enabled
due to open-ended upper ranges of certain performance characteristics.
However, these cases concerned arts that are far less predictable than the
gear systems at issue here. See MagSil Corp. v. Hitachi Global Storage
Techs., Inc., 687 F.3d 1377, 1378–79, 1381 (Fed. Cir. 2012) (applying
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electromagnetic energy to a quantum mechanical effect tunnel junction
“causes a change in resistance by at least 10% at room temperature,” where
“the inventors’ best efforts [had] achieved a maximum change in resistance
of only 11.8% at room temperature”); Fisher, 427 F.2d at 839 (drug potency
of “at least 1 International Unit of ACTH per milligram,” which unlike
“mechanical” cases involving “predictable factors,” concerns “unpredictable
factors” such as “chemical reactions and physiological activity”). Thus, the
results reached in those cases are distinguished from the facts presented
here.
The Examiner cites various items of evidence reflecting the time and
money spent to develop commercial gas turbine engines. This evidence
does not persuade us of lack of enablement. The enablement inquiry
concerns whether a person of ordinary skill in the art is able to make and use
the full scope of the claimed invention. That is, can it be done? Developing
a commercially acceptable engine, by contrast, encompasses many
additional considerations. For example, Jane’s Aero-Engines identifies the
“prime requirements driving current civil aircraft engine developments” as
including: (1) “reduced costs, throughout the whole life cycle of the engine”
by achieving “reduced purchase costs,” “reduced fuel consumption,” and
“increased component life”; (2) “reduced environmental impact”;
(3) “improved reliability”; and (4) “levels of safety as good as or better than
those being achieved today.” Jane’s Aero-Engines, 21. Many of these
considerations have little or nothing to do with whether a person of ordinary
skill in the art could make or use a gear system with a gear reduction ratio
that greatly exceeds 2.5.
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The strongest evidence against enablement in this regard is provided
by Warwick and Coy, which focus on the gear system(s) being developed by
Pratt & Whitney. Warwick indicates “P&W believes its GTF geared
turbofan is a ‘game changer,’” and “P&W has already spent $1 billion over
the past 20 years on geared turbofan research and development, and its
spending is running at $100 million a year.” Warwick, 1. Coy concludes
“Pratt & Whitney’s new PurePower Geared Turbofan aircraft engines are
impressive beasts.” Coy, 1. However, these articles demonstrate, when read
as a whole, that large portions of Pratt & Whitney’s research and
development were directed to optimization of a geared turbofan engine for
commercial use, not simply making a geared turbofan engine that will work.
There is little evidence of record directed to the latter issue, which is the
critical issue here.
For the foregoing reasons, we do not sustain the rejection of claim 1
as lacking enablement.
Claims 3–10
Claims 3–10 are rejected for lack of enablement based solely on the
challenged subject matter of their common parent claim 1. See Final
Act. 12–24, 46–59. For the reasons provided above in connection with
claim 1, we do not sustain the enablement rejection of claims 3–10.
Claim 14
The Examiner determines Appellant’s Specification does not enable a
gas turbine engine comprising a low pressure turbine pressure ratio of
greater than five (5), as recited in claim 14, because the recited range “is not
bounded at its upper limit and therefore includes pressure ratios ranging
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from 5 to 10, 50, 100, 500, . . . , 5000 and greater.” Final Act. 12. The
Examiner notes “the scope of the claims must bear a reasonable correlation
to the scope of enablement provided by the specification to persons of
ordinary skill in the art.” Id. at 13–14, 21–22 (emphasis omitted) (quoting
Fisher, 427 F.2d at 839). The Examiner also determines Appellant “cannot
rely on the knowledge of one skilled in the art to supply information that is
required to enable the novel aspect of the claimed invention when the
enabling knowledge is in fact not known in the art.” Id. at 16–17 (citing
ALZA, 603 F.3d at 941; and MPEP § 2161.0(III)). The Examiner, further,
provides an analysis of the Wands factors. Id. at 18–19.
The Examiner finds Pratt & Whitney took 20–30 years and spent
several hundreds of millions of dollars to develop the GTF engine, despite
that other turbines were already known to have pressure ratios of between
about 4 to 9.5. Final Act. 16 (citing Boggia, Fig. 5; Warwick; Coy).
Applying the Scripps decision, supra, the Examiner finds the turbine
pressure ratio at issue here does “not have an inherent upper limit,” because
it is an engineering design variable. Final Act. 23–24 (emphasis by
Examiner), 49–50. The Examiner takes official notice that, as technology
has advanced and will continue to advance over time, stronger and lighter
materials will be created, thus increasing achievable turbine pressure ratios.
Id. at 50–51; Ans. 16–17. The Examiner further determines Appellant’s
Specification fails to enable a person of ordinary skill in the art to approach
any sort of limit, because it does not describe any details of a turbine
structure to achieve an unbounded limit. Final Act. 24, 46–49.
Appellant argues a person of ordinary skill in the art would know that
a turbine pressure ratio has “a practical upper limit that is far short from
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infinity,” based on constraints imposed for a feasibly working gas turbine
engine. Appeal Br. 5–8. Appellant contends “an infinitely high [turbine]
pressure ratio would neither be desirable nor achievable,” because this
“would cause a complete obstruction of the flow of combustion products
through the gas path, rendering the engine inoperable.” Id. at 8. Appellant
additionally asserts the “Examiner’s own research” demonstrates that gas
turbine engine advances “occur in small predictable increments over a long
period of time,” and “that the gas turbine engine art is mature.” Id. at 7.
The Examiner replies that Appellant’s Specification “failed to disclose
any space limitations, material limitations, weight limitations, operational
limitations, etcetera,” and Appellant has “failed to explain how one of
ordinary skill in the art could determine the alleged practical upper limits
of . . . the [turbine] pressure ratio.” Final Act. 49–50, 57; Ans. 8–11, 15–16,
28–32.
Upon consideration of the foregoing, we note first that the subject
matter at issue (Wands factor (4)) is a low pressure turbine having “a
pressure ratio that is greater than about five (5).” Claims App. 3. The low
pressure turbine converts the energy of an expanding airflow to a rotational
energy, to drive the low pressure compressor and the fan. Spec. ¶ 30. The
amount of converted energy is reflected by the turbine’s pressure ratio value.
Id. ¶ 29.
We appreciate that Appellant’s Specification in the foregoing regards
is sparse, and Appellant’s figures are highly schematic (Wands factors
(1)–(3)), thus requiring some amount of experimentation to implement the
claimed invention. A person of ordinary skill in the art would have known
that a low pressure turbine has an alternating series of stationary and rotating
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blades to convert the energy of an expanding airflow to a rotational energy.
See Jane’s Aero-Engines, 14 (Figure), 16 (low pressure turbine “uses several
alternating sets of nozzle guide vanes and rotor blades to extract enough
power to drive the fan”). We determine the state of the art of low pressure
turbines was advanced, and low pressure turbines were highly predictable, at
the time of Appellant’s invention (Wands factors (5) and (7)). A person of
ordinary skill in the art would have known how to change the size and
configuration of the turbine blades to achieve a desired pressure ratio
(Wands factors (6) and (7)).
As to the breadth of the claims (Wands factor (8)), we determine a
person of ordinary skill in the art would have appreciated that the claimed
pressure ratio has an inherent, albeit not precisely known, upper limit.
Scripps, 566 F.3d at 1572. The ratio equals the “pressure measured prior to
inlet of low pressure turbine 18 as related to the pressure at the outlet of the
low pressure turbine 18 prior to exhaust nozzle.” Spec. ¶ 29. It is therefore
mathematically limited by an inherent maximum pressure achievable at the
turbine inlet. This inherent maximum limitation arises from the finitely
available airflow to drive the low pressure turbine, and the fact that the high
pressure turbine will dissipate some of the airflow’s energy before it reaches
the low pressure turbine. See Spec. ¶ 30, Fig. 1A. The inherent maximum
limitation arises further from the finite capabilities of the fan, the high and
low pressure compressors, and the combustor disposed upstream of the low
pressure turbine. See id.
The Examiner cites two cases holding that claims were not enabled
due to open-ended upper ranges of certain performance characteristics. As
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explained above with respect to claim 1, the results reached in those cases
are distinguished from the facts presented here.
The Examiner cites various items of evidence reflecting the time and
money spent to develop commercial gas turbine engines. This evidence
does not persuade us of lack of enablement, for substantially the same
reasons discussed above in connection with the gear system of claim 1.
For the foregoing reasons, we do not sustain the rejection of claim 14
as lacking enablement.
Claims 15 and 17
The Examiner determines Appellant’s Specification does not enable a
gas turbine engine comprising a bypass ratio greater than six (6) as recited in
claim 15, or greater than ten (10) as recited in claim 17, because the recited
ranges are “not bounded at [their] upper limit and therefore include[] bypass
ratios ranging from 6 to 15, 25, 50, 100, . . . , 250 and greater.” Final
Act. 12–13. The Examiner notes “the scope of the claims must bear a
reasonable correlation to the scope of enablement provided by the
specification to persons of ordinary skill in the art.” Id. at 13–14, 21–22
(emphasis omitted) (quoting Fisher, 427 F.2d at 839). The Examiner also
determines Appellant “cannot rely on the knowledge of one skilled in the art
to supply information that is required to enable the novel aspect of the
claimed invention when the enabling knowledge is in fact not known in the
art.” Id. at 16–17 (citing ALZA, 603 F.3d at 941; and MPEP § 2161.0(III)).
The Examiner, further, provides an analysis of the Wands factors. Id. at
18–19.
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The Examiner finds Pratt & Whitney took 20–30 years and spent
several hundreds of millions of dollars to increase the bypass ratio of 10 in
the PW8000 engine to 10–12 in the GTF engine, despite that other engines
were already known to have bypass ratios of 12.5. Final Act. 14–16, 19
(citing Rauch, 1, 6; Jane’s Aero-Engines, 510–512; Warwick; Coy). The
Examiner also finds Rolls Royce, a competitor of Pratt & Whitney in the gas
turbine engine market, similarly took 18 years of research and development
to achieve a bypass ratio of 11 or 15. Id. at 20–21 (citing Read7).
Applying the Scripps decision, supra, the Examiner finds the bypass
ratio at issue here does “not have an inherent upper limit,” because it is an
engineering design variable. Final Act. 23–24 (emphasis by Examiner),
49–50. The Examiner takes official notice that, as technology has advanced
and will continue to advance over time, stronger and lighter materials will be
created, thus increasing achievable bypass ratios. Id. at 50–51; see also id.
at 51–56 (extended discussion of engine bypass ratios over time);
Ans. 23–27 (additional discussion). The Examiner further determines
Appellant’s Specification fails to enable a person of ordinary skill in the art
to approach any sort of limit, because it does not describe any details of an
engine structure to achieve an unbounded limit. Final Act. 24, 46–49.
Appellant argues a person of ordinary skill in the art would know that
a bypass ratio has “a practical upper limit that is far short from infinity,”
based on constraints imposed for a feasibly working gas turbine engine.
Appeal Br. 5–8. For example, according to Appellant, “[t]he minimum
amount of airflow required to operate the engine,” and practical limitations

7 B. Read, Powerplant Revolution, AeroSpace (May 2014), at 28–31.
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on the overall size of an aircraft engine, “provide[] an inherent practical
upper limitation to the claimed bypass ratio.” Id. at 8. Appellant
additionally asserts the “Examiner’s own research” demonstrates that gas
turbine engine advances “occur in small predictable increments over a long
period of time,” and “that the gas turbine engine art is mature.” Id. at 7.
The Examiner replies that Appellant’s Specification “failed to disclose
any space limitations, material limitations, weight limitations, operational
limitations, etcetera,” and Appellant has “failed to explain how one of
ordinary skill in the art could determine the alleged practical upper limits
of . . . the bypass ratio.” Final Act. 49–50, 57; Ans. 8–11, 15–16, 28–32.
The Examiner, further, cites additional evidence concerning advances in
materials required to make longer fan blades to accommodate an increase in
engine size for a higher bypass ratio. Ans. 12–15 (citing “Eric Adams, ‘The
World’s Hugest Jet Engine is Wider than a 737’s Fuselage’, April 28, 2016,
Pgs. 2 and 3”).
Upon consideration of the foregoing, we note first that the subject
matter at issue (Wands factor (4)) is a gas turbine engine having a bypass
flow that “defines a bypass ratio greater than six (6)” or “greater than
ten (10).” Claims App. 3–4. The bypass flow area is “disposed radially
outward of the primary core exhaust path,” defining an “annular” space
around the engine core. Id.; Spec. ¶¶ 3, 31, Fig. 1A (bypass flow path 40
lies between core nacelle 12 and fan nacelle 34). Thus, the airflow delivered
by the engine’s fan is split into two paths, a first path through the engine
core to power the engine, and a second “bypass” path surrounding the engine
core to provide thrust for the aircraft. Spec. ¶¶ 3, 28–31, Fig. 1A (arrows
showing core engine airflow path to exhaust E, and bypass flow path B).
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We appreciate that Appellant’s Specification in the foregoing regards
is sparse, and Appellant’s figures are highly schematic (Wands factors
(1)–(3)), thus requiring some amount of experimentation to implement the
claimed invention. We determine the state of the art of high bypass flow
engines was advanced and predictable at the time of Appellant’s invention
(Wands factors (5) and (7)). A person of ordinary skill in the art would have
known how to change the relative sizes of the engine core nacelle (such as
nacelle 12 in Appellant’s Figure 1) and the fan nacelle (nacelle 34), as well
as the geometry of the engine downstream of the fan (fan 20) where the
airflow paths diverge, to achieve a desired bypass ratio (Wands factors (6)
and (7)).
As to the breadth of the claims (Wands factor (8)), we determine a
person of ordinary skill in the art would have appreciated that the claimed
bypass ratio has an inherent, albeit not precisely known, upper limit.
Scripps, 566 F.3d at 1572. The ratio reflects how much larger the bypass
airflow path is, versus the core engine airflow path. This inherent upper
limit arises from the fact that the fan nacelle (such as nacelle 34 in
Appellant’s Figure 1) cannot be infinitely large, and the engine core nacelle
(nacelle 12) cannot be infinitely small, while still forming a working gas
turbine engine.
The Examiner cites two cases holding that claims were not enabled
due to open-ended upper ranges of certain performance characteristics. As
explained above with respect to claim 1, the results reached in those cases
are distinguished from the facts presented here.
The Examiner cites various items of evidence reflecting the time and
money spent to develop commercial gas turbine engines. This evidence
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does not persuade us of lack of enablement, for substantially the same
reasons discussed above in connection with the gear system of claim 1.
For the foregoing reasons, we do not sustain the rejection of claims 15
and 17 as lacking enablement.
C. Definiteness (Claims 1, 3–10, 14, 15, and 17)
“[T]he statutory language of ‘particular[ity]’ and ‘distinct[ness]’” in
35 U.S.C. § 112, second paragraph, requires claims “to be cast in clear—as
opposed to ambiguous, vague, indefinite—terms.” In re Packard, 751 F.3d
1307, 1313 (Fed. Cir. 2014). A claim is indefinite when it contains words or
phrases whose meaning is unclear to a person of ordinary skill in the art. Ex
parte McAward, Appeal No. 2015–006416, 2017 WL 3669566, at *2–6
(PTAB Aug. 25, 2017) (precedential); Ex parte Miyazaki, Appeal No. 2007–
3300, 2008 WL 5105055, at *4 (BPAI Nov. 19, 2008) (precedential) (“[t]he
test for definiteness under 35 U.S.C. § 112, second paragraph, is whether
‘those skilled in the art would understand what is claimed when the claim is
read in light of the specification’”) (quoting Orthokinetics, Inc. v. Safety
Travel Chairs, Inc., 806 F.2d 1565, 1576 (Fed. Cir. 1986)).
The Examiner determines the claim term “greater than” in claims 1,
14, 15, and 17 “is indefinite as it is not bounded at its upper limit; therefore,
applicant has failed to define the metes and bounds of applicant’s claimed
invention.” Final Act. 25 (emphasis by Examiner); Ans. 40.
Appellant responds that the claims are not unclear, and “[t]he
Examiner’s requirement that both upper and lower limits be explicitly
recited is legally unfounded.” Appeal Br. 9–10. Further according to
Appellant, “even if an upper limit were required,” “there are practical and
inherent physical upper limits to the claimed gear ratio, pressure ratio, and
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bypass ratios [based on] the basic architecture of a bypass turbine engine.”
Id. at 10; Reply Br. 6–7. Appellant cites Fisher, 427 F.2d at 838, as holding
that “the recitation of an open-ended ratio of ‘at least 1 International Unit of
ACTH per milligram’ was definite.” Appeal Br. 10.
The Examiner replies that the Fisher decision is distinguishable here,
because it addressed definiteness of the term “International Unit,” not the
definiteness of an open-ended range. Ans. 40–42. The Examiner also
concludes Appellant has “failed to explain how one of ordinary skill in the
art could determine the alleged inherent limitations of the gear reduction
ratio, the pressure ratio, and the (BPR) bypass ratio,” and Appellant’s
Specification “failed to disclose any constraints that would have placed the
alleged physical and structural limitation on the claimed open-ended figures
of merit.” Id. at 42–43.
We conclude the claims at issue here are not unclear, simply because
they fail to place an express upper boundary on the claimed ranges of values
for a gear reduction ratio, a low pressure turbine pressure ratio, and a bypass
ratio. The claims may be broad in these respects, but they are not unclear.
As in Fisher, this breadth of the claims may raise the issue of whether
Appellant’s disclosure enables the claimed invention, but the claims are not
thereby indefinite. See Fisher, 427 F.2d at 838 (claims are not indefinite for
failing to identify the amino acid structure beyond the 24th position in the
claimed compound).
Thus, we do not sustain the rejection of claims 1, 3–10, 14, 15, and 17
as indefinite.
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D. Dependent Form (Claims 5 and 6)
The Examiner determines claim 5 fails to “specify a further
limitation” of claim 1 as required by 35 U.S.C. § 112, ¶ 4. Final Act. 25–27.
The Examiner’s position is that claim 5 is inconsistent with subject matter
recited in claim 1. Id. In particular, claim 1 recites fan exit guide vanes
which are “rotatable about an axis of rotation [that] is located about a
geometric center of gravity of a cross-section of the fan exit guide vane
taken parallel to the engine centerline axis.” Claims App. 2; Final Act. 26.
Claim 5 depends from claim 1, and recites that each fan exit guide vane
includes “a pivotable portion rotatable about said axis of rotation relative a
fixed portion,” and claim 6 depends from claim 5. Claims App. 3; Final
Act. 26–27.
Appellant argues the rejection is improper, because claim 5 “recite[s]
features disclosed in Figures 3A–C” of Appellant’s Specification. Appeal
Br. 11 (citing Spec. ¶ 39).
The Examiner replies that claims 1 and 5, when read together,
improperly “combin[e] two different embodiments that are not disclosed as
being combinable.” Ans. 44–50 (emphasis by Examiner). The Examiner
interprets claim 1 as encompassing the embodiment of Figures 2A–2C but
not the embodiment of Figures 3A–3C, and interprets claim 5 as
encompassing the embodiment of Figures 3A–3C but not the embodiment of
Figures 2A–2C. Id. Appellant, in response, cites the arguments presented in
the Appeal Brief. Reply Br. 7.
Claim 1 requires a guide vane having an axis of rotation that “is
located about a geometric center of gravity of a cross-section of the” guide
vane. Claims App. 2. That limitation encompasses the embodiment of
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Appellant’s Figures 2A–2C, wherein guide vane 50 has axis of rotation 60,
which is located about the geometric center of gravity of the cross-section of
vane 50 shown in the Figures. See Spec. ¶¶ 18–20, 35–36. The limitation
does not encompass the embodiment of Appellant’s Figures 3A–3C, wherein
guide vane 50ʹ has pivoting portion 66P which pivots around axis of
rotation 60 relative to fixed portion 66F. Id. ¶¶ 21–23, 39. As the Examiner
explains, the pivoting movement of portion 66P relative to portion 66F
changes the geometric center of gravity of guide vane 50ʹ, such that the
center does not coincide with the axis of rotation, as is required by claim 1.
See Ans. 44–50.
Although the Examiner sets forth reasons why claims 5 and 6 may be
indefinite or lack written description support, the Examiner has failed to
establish sufficiently that claim 5 is an improper dependent claim. We see
no persuasive reason why claim 5 does not further limit claim 1, even if
those further limitations may mix various embodiments from Appellant’s
Specification, or result in an indefinite claim. Accordingly, we do not
sustain the Examiner’s decision to reject claims 5 and 6 as improper under
35 U.S.C. § 112, ¶ 4.
E. Obviousness Over Coplin, Gisslen, Neitzel, Suljak, and Dunbar ’187
(Claims 1, 3, 4, 7, and 10)
Claim 1
The Examiner finds Coplin discloses, in Figures 1–2, gas turbine
engine 10 having each and every limitation of claim 1, except for (1) a fan
variable area nozzle at the exit of the bypass flow path, and (2) rotatable fan
exit guide vanes in the bypass flow path. Final Act. 28–29. In the latter
regard, the Examiner finds Coplin’s engine 10 has fan exit guide vanes 112,
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but vanes 112 are not rotatable. Id.; Coplin, Fig. 1, 2:43–45, 3:42–46,
5:31–34 (engine 10 has fan casing 108 secured to core casing 22 by a
plurality of circumferentially arranged struts 112, located downstream of
fan 76). Appellant does not dispute these findings, which we find are
supported by a preponderance of the evidence. See Final Act. 28 (annotating
Coplin, Fig. 1, to illustrate findings); Appeal Br. 11–13 (no disputes);
37 C.F.R. § 41.37(c)(1)(iv) (arguments not included in Appeal Brief are
waived).
For the recited fan variable area nozzle at the exit of the bypass flow
path, the Examiner finds Gisslen discloses a gas turbine engine having this
feature. Final Act. 29–30. In particular, the Examiner finds Gisslen’s
engine 10 has fan variable area nozzle 20 that is moveable relative to fan
nacelle 14 to vary the exit area and adjust a pressure ratio of the bypass
airflow during engine operation. Id.; see Gisslen, Figs. 1–3, 1:55–61,
1:66–67, 2:5–15. The Examiner determines it would have been obvious to
modify Coplin’s engine 10 to incorporate this feature, based on the express
teaching in Gisslen that “it is often necessary or desirable to provide a
variable area exhaust nozzle to enhance performance during various modes
of engine operation such as take-off, cruise or climb.” Gisslen, 1:6–14
(emphasis added); Final Act. 30.
Appellant responds that Coplin teaches away from this proposed
modification, because it is contrary to Coplin’s intended purpose. Appeal
Br. 13. Appellant asserts Coplin already has “flaps or petals 114 that
provide a variable exhaust nozzle from the core engine [12],” for
“controlling operation of the fan [72] by controlling the rotational speed of
the turbine [20] driving the fan to control thrust during take-off conditions.”
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Id. (emphasis added). Further according to Appellant, Coplin’s intended
purpose is “to provide an engine of reduced size and weight,” including “that
a diameter and length of the fan casing is minimized.” Id. (citing Coplin,
8:30–42, 6:39–48). Appellant contends adding a fan variable area nozzle at
the exit of the bypass flow path in Coplin’s engine 10, therefore, is contrary
to the intended purpose of Coplin. Id.
We determine the Examiner has provided a rational underpinning,
supported by a preponderance of the evidence, sufficient to support the legal
conclusion of obviousness. See In re Kahn, 441 F.3d 977, 988 (Fed. Cir.
2006), cited with approval in KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398,
418 (2007). In particular, Gisslen discloses that it may be necessary, or at
least desirable, to provide a variable area exhaust nozzle to tailor the
performance of a gas turbine engine to different phases of an airplane flight,
such as take-off, cruise, and climb. Gisslen, 1:6–14. This teaching provides
ample motivation for a person of ordinary skill in the art to add a variable
area exhaust nozzle to Coplin’s engine 10.
Coplin does not teach away from this modification, because Coplin
does not criticize, discredit, or discourage using a variable area exhaust
nozzle in Coplin’s engine 10. See In re Fulton, 391 F.3d 1195, 1201
(Fed. Cir. 2004). Appellant argues Coplin’s pivoting flaps 114 already
perform the same function that would be provided by a variable area exhaust
nozzle. Appeal Br. 13. However, this argument is unsupported by any
citation to or discussion of Coplin’s disclosure. See id. Based on our review
of Coplin’s disclosure, we find flaps 114, which are disposed directly
downstream of low pressure turbine 20 at the exit of engine core 12, are used
“to vary the expansion ratio of” low pressure turbine 20. See Coplin, Fig. 1,
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3:15, 5:39–45. Thus, flaps 114 are not used to vary the pressure ratio across
fan 72, which is the function performed by a variable area exhaust nozzle
placed at the exit of Coplin’s bypass flow path. We appreciate that low
pressure turbine 20 powers fan 72. See id. at 3:20–22, 5:45–52. However,
the principal purpose of flaps 114 is to maximize the fuel economy of the
engine by changing fan speed during different phases of an airplane flight,
not by varying the pressure ratio across fan 72. See id. at 5:45–63. Thus, we
find Coplin’s existing flaps 114 do not teach away from adding a variable
area exhaust nozzle at the exit of Coplin’s bypass flow path.
We also appreciate that Coplin, like most engine designers, would
generally prefer a lighter and smaller gas turbine engine, all things being
equal. See, e.g., Coplin, Abstract, 1:9–18, 1:31–34, 1:57–62, 6:14–15,
6:39–48, 6:62–65, 8:30–42; Polaris Indus., Inc. v. Arctic Cat, Inc., 882 F.3d
1056, 1067–70 (Fed. Cir. 2018) (even in the absence of a teaching away,
general preferences as stated in the prior art are still relevant to determining
whether a skilled artisan would be motivated to combine the prior art in the
manner claimed). However, not all things are equal here. For example,
Coplin discloses that reduction gear assembly 62 beneficially improves the
efficiency of engine 10, despite the weight added to engine 10 by gear
assembly 62. See Coplin, 1:38–46, 3:27–41, 3:52–61. Similarly, Gisslen
discloses that a fan variable area nozzle enhances engine performance,
despite the weight added by the variable nozzle. See Gisslen, 1:6–9, 2:5–23.
Thus, weighing the evidence as a whole, we determine a person of ordinary
skill in the art would have been motivated to pursue the desirable
performance characteristics provided by adding a variable area exhaust
nozzle to Coplin’s engine 10, despite the resulting increase in engine weight.
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See In re Urbanski, 809 F.3d 1237, 1243–44 (Fed. Cir. 2016) (person of
ordinary skill in the art may be motivated to pursue desirable properties of
one prior art reference, even at the expense of foregoing a benefit taught by
another prior art reference).
Next, for the recited “rotatable” fan exit guide vanes, the Examiner
relies upon the combined disclosures of Neitzel, Suljak, and Dunbar ’187.
Final Act. 30–34. The Examiner finds Neitzel discloses, as shown in
Figure 3, a gas turbine engine having fan exit guide vanes (i.e., outlet guide
vanes 48) rotatable about an axis of rotation to vary a fan bypass flow path
(i.e., bypass duct 58), wherein the axis of rotation is located about a
geometric center of gravity of a cross-section of the fan exit guide vanes
taken parallel to the engine centerline axis. Final Act. 30–31; see Neitzel,
4:6–8, 4:40–41. The Examiner finds Suljak discloses that guide vanes were
conventionally rotated around a geometric center of gravity of the airfoil
cross-section. Final Act. 31 (citing Suljak ¶ 21). The Examiner finds
Dunbar ’187 discloses, as shown in Figure 1, rotatable fan exit guide
vanes 52 disposed downstream of fan blades 30. Id. (citing Dunbar ’187,
1:42–51, 2:18–44, 3:65–4:20).
Based on those teachings of Neitzel, Suljak, and Dunbar ’187, the
Examiner determines it would have been obvious to modify Coplin’s
engine 10 so that fan exit guide vanes 112 are rotatable about their geometric
centers of gravity. Id. at 31–34. As motivation, the Examiner finds
Dunbar ’187 discloses “that pivoting/rotating a multiple of fan exit guide
vanes facilitated improved engine efficiency by reducing the bypass air swirl
angle which reduced drag and increased engine thrust.” Id. at 31 (citing
Dunbar ’187, 1:42–51, 2:18–44, 3:65–4:20). The Examiner further
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determines that rotating Coplin’s vanes 112 about their geometric centers of
gravity would have advantageously reduced the amount of force required to
rotate vanes 112, “because the moments generated by the upstream air
pressure on opposite sides of [vanes 112] would have substantially canceled
each other out,” thereby reducing the size, weight, and cost of rotating
vanes 112. Id. at 31–32.
Appellant argues the Examiner errs in relying on Neitzel in the
foregoing regards. See Appeal Br. 11–13. We agree. Neitzel’s gas turbofan
aircraft engine 30, shown in Figures 2–3, is “convertible” between a
turbofan mode and a turboshaft mode. Neitzel, 1:5–20, 3:36–40. In
turbofan mode, engine 30 rotates fan 32 to provide forward thrust for the
aircraft, in a similar fashion to Coplin’s engine 10. Id. at 1:11–17, 3:40–50.
In turboshaft mode, engine 30 rotates vertical shaft 42 to power a helicopter
rotor to provide vertical thrust. Id. at 1:11–17, 3:40–60.
Neitzel’s outlet guide vanes 48, cited by the Examiner, are rotated
between an open position for turbofan mode, and a closed position for
turboshaft mode to reduce the power absorbed by fan 32 as well as residual
forward thrust in turboshaft mode. Id. at 3:61–4:8, 5:2–11. The Examiner
does not cite, and we cannot find, any disclosure in Neitzel indicating outlet
guide vanes 48 are rotated in a variable manner during turbofan mode to
improve the performance of engine 30 in that mode. See Final Act. 30–34;
Ans. 60–62. Thus, there is little or no relationship between Neitzel’s
rotating outlet guide vanes 48 and whether it would have been obvious to
modify Coplin’s stationary outlet guide vanes 112 to be rotatable to improve
engine performance in Coplin’s engine 10, which is not convertible.
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Nonetheless, Suljak and Dunbar ’187 provide a rational underpinning
sufficient to support the legal conclusion of obviousness here. Appellant
does not address Suljak and Dunbar ’187. See Appeal Br. 11–14.
Dunbar ’187 discloses fan exit guide vanes 52 disposed downstream of fan
blades 30, wherein vanes 52 are rotated “to reduce losses, improve fan
bypass efficiency and increase fan bypass stall margin.” Dunbar ’187,
Fig. 1, 1:42–51, 3:65–4:19. “[S]ignificant increases in specific fuel
consumption can be achieved” by such controlled rotation of vanes 52. Id.
at 2:18–44. Thus, a preponderance of the evidence supports the Examiner’s
determination that it would have been obvious to modify Coplin’s stationary
vanes 112 to be rotatable, to achieve the advantages disclosed by
Dunbar ’187.
Dunbar ’187 further discloses the pitch of vanes 52 “could be varied
by having only the vane leading edge or vane trailing edge pivotable or by
otherwise varying the effective angle of incidence of the vanes, as is known
to those skilled in the art.” Dunbar ’187, 3:52–57 (emphasis added). Suljak
correspondingly discloses “[a]irfoils are conventionally rotated around the
geometric center of gravity (CG) of the airfoil cross section.” Suljak ¶ 21.
Thus, the combination of Dunbar ’187 and Suljak establishes the
obviousness of rotating Coplin’s vanes 112 about their respective geometric
centers of gravity, as claimed.
For the foregoing reasons, we sustain the rejection of claim 1 as
having been obvious over Coplin, Gisslen, Neitzel, Suljak, and Dunbar ’187.
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Claims 3, 4, 7, and 10
Appellant does not present further argument against the rejections of
claims 3, 4, 7, and 10 as having been obvious over Coplin, Gisslen, Neitzel,
Suljak, and Dunbar ’187. Appeal Br. 11–13. For the reasons provided
above, we sustain these rejections. See 37 C.F.R. § 41.37(c)(1)(iv).
F. Obviousness Over Coplin, Gisslen, Neitzel, Suljak, Dunbar ’187, and
One or More of Dunbar ’763, Ferri, Rauch, Boggia, and
Jane’s Aero-Engines (Claims 5, 6, 8, 9, 14, 15, and 17)
Appellant does not present further argument against the rejections of
claims 5, 6, 8, 9, 14, 15, and 17 as having been obvious over Coplin,
Gisslen, Neitzel, Suljak, Dunbar ’187, and one or more of Dunbar ’763,
Ferri, Rauch, Boggia, and Jane’s Aero-Engines. Appeal Br. 13–14. For the
reasons provided above, we sustain these rejections. See 37 C.F.R.
§ 41.37(c)(1)(iv).
DECISION
The rejection of claims 1, 3–10, 14, 15, and 17 under 35 U.S.C. § 112,
first paragraph, for lack of written description, is reversed.
The rejection of claims 1, 3–10, 14, 15, and 17 under 35 U.S.C. § 112,
first paragraph, for lack of enablement, is reversed.
The rejection of claims 1, 3–10, 14, 15, and 17 under 35 U.S.C. § 112,
second paragraph, as indefinite, is reversed.
The rejection of claims 5 and 6 under 35 U.S.C. § 112, fourth
paragraph, as being of improper dependent form, is reversed.
The rejection of claims 1, 3, 4, 7, and 10 under 35 U.S.C. § 103(a), as
unpatentable over Coplin, Gisslen, Neitzel, Suljak, and Dunbar ’187, is
affirmed.
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The rejection of claims 5 and 6 under 35 U.S.C. § 103(a), as
unpatentable over Coplin, Gisslen, Neitzel, Suljak, Dunbar ’187,
Dunbar ’763, and Ferri, is affirmed.
The rejection of claims 8 and 9 under 35 U.S.C. § 103(a) as
unpatentable over Coplin, Gisslen, Neitzel, Suljak, Dunbar ’187, and Rauch,
is affirmed.
The rejection of claim 14 under 35 U.S.C. § 103(a) as unpatentable
over Coplin, Gisslen, Neitzel, Suljak, Dunbar ’187, and Boggia, is affirmed.
The rejection of claims 15 and 17 under 35 U.S.C. § 103(a) as
unpatentable over Coplin, Gisslen, Neitzel, Suljak, Dunbar ’187, and Jane’s
Aero-Engines, is affirmed.
In summary:
Claim(s)
Rejected
Basis Affirmed Reversed
1, 3–10, 14,
15, 17
§ 112, ¶ 1 (Written Description) 1, 3–10, 14,
15, 17
1, 3–10, 14,
15, 17
§ 112, ¶ 1 (Enablement) 1, 3–10, 14,
15, 17
1, 3–10, 14,
15, 17
§ 112, ¶ 2 1, 3–10, 14,
15, 17
5, 6 § 112, ¶ 4 5, 6
1, 3, 4, 7, 10 § 103 Coplin, Gisslen, Neitzel, Suljak,
Dunbar ’187
1, 3, 4, 7, 10
5, 6 § 103 Coplin, Gisslen, Neitzel, Suljak,
Dunbar ’187, Dunbar ’763, Ferri
5, 6
8, 9 § 103 Coplin, Gisslen, Neitzel, Suljak,
Dunbar ’187, Rauch
8, 9
14 § 103 Coplin, Gisslen, Neitzel, Suljak,
Dunbar ’187, Boggia
14
15, 17 § 103 Coplin, Gisslen, Neitzel, Suljak,
Dunbar ’187, Jane’s Aero-Engines
15, 17
Overall
Outcome
1, 3–10, 14,
15, 17

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No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a)(1)(iv).
AFFIRMED