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Patent Trials and Appeals Board

Jun 4, 2020

15134653 - (D) (P.T.A.B. Jun. 4, 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.
15/134,653 04/21/2016 Jorge I. Farah 64542US03;
67097-2239PUS2
1070
54549 7590 06/04/2020
CARLSON, GASKEY & OLDS/PRATT & WHITNEY
400 West Maple Road
Suite 350
Birmingham, MI 48009
EXAMINER
SUTHERLAND, STEVEN M
ART UNIT PAPER NUMBER
3741
NOTIFICATION DATE DELIVERY MODE
06/04/2020 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 JORGE I. FARAH, KALPENDU J. PAREKH, and
CONSTANTINE BALTAS

Appeal 2020-000455
Application 15/134,653
Technology Center 3700
____________

Before MICHAEL L. HOELTER, BRETT C. MARTIN, and
JEREMY M. PLENZLER, Administrative Patent Judges.

HOELTER, 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, 2, 5, 7–9, 14–16, 18, 19, and 21–25,
which constitute all the claims pending in this application. Claims 3, 4, 6,
10–13, 17, and 20 have been cancelled. 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 United
Technologies Corporation. See Appeal Br. 1.
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CLAIMED SUBJECT MATTER
The disclosed subject matter relates to “[a] gas turbine engine [which]
typically includes a fan section, a compressor section, a combustor section
and a turbine section.” Spec. ¶ 2. Apparatus claims 1 and 9, and method
claim 16, are independent. Claim 1 is illustrative of the claims on appeal,
and is reproduced below.
1. A gas turbine engine comprising:
a fan situated at an inlet of a bypass passage, the fan
having a fan diameter, Dfan;
a low pressure turbine section configured to drive the fan
and a first compressor section, the low pressure turbine section
having a greater number of stages than the first compressor
section, wherein the high pressure turbine section includes two
stages and the first compressor section includes three stages,
and the low pressure turbine section having a maximum rotor
diameter, Dturb;
a high pressure turbine section configured to drive a
second compressor section; and wherein a ratio of the
maximum rotor diameter Dturb divided by the fan diameter
Dfan is less than 0.6.
EVIDENCE
Name Reference Date
White US 3,034,298 May 15, 1962
Lee et al. (“Lee”) US 2008/0112791 A1 May 15, 2008

Joachim Kurzka, Fundamental Differences Between Conventional and
Geared Turbofans, ASME, pp. 145–53 (2009) (“Kurzka”).

Mark H. Waters, et al., Analysis of Turbofan Propulsion System Weight and
Dimensions, NASA Technical Memorandum (January, 1977) (“Waters”).
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REJECTIONS
Claims 2, 9, 14–16, 18, 19, and 23–25 are rejected under 35 U.S.C.
§ 112 (pre-AIA), first paragraph, as failing to comply with the enablement
requirement.
Claims 2, 5, 9, 14–16, 18, 19, and 23–25 are rejected under 35 U.S.C.
§ 112 (pre-AIA), second paragraph, as being indefinite.
Claims 1, 2, 5, 9, 16, 18, and 19 are rejected under pre-AIA 35 U.S.C.
§ 103(a) as unpatentable over Kurzka, Waters, and Lee.
Claims 7, 8, and 21–25 are rejected under pre-AIA 35 U.S.C. § 103(a)
as unpatentable over Kurzka, Waters, Lee, and White.
ANALYSIS
The rejection of claims 2, 9, 14–16, 18, 19, and 23–25
as failing to comply with the enablement requirement
Each of these claims includes the limitation of “a bypass ratio of
greater than 10,” a bypass ratio that “is greater than 6,” or the like. The
Examiner concludes that because these limitations “are not bounded at an
upper limit,” they therefore include “ratios ranging from the lower bounds to
infinity.” Final Act. 2; see also Ans. 3. As a consequence, “[t]he disclosure
as originally filed does not enable such large bypass ratios.” Final Act. 2.
In reaching this conclusion, the Examiner addresses such factors as
breadth of the claims, nature of the invention, state of the prior art, and the
level of ordinary skill in the art (the latter possessing “a master’s degree with
an average of twenty years[ of] experience”). See Final Act 2–3 (referencing
In re Wands, 858 F.2d 731 (Fed. Cir. 1988)). The Examiner also addresses
the guidance outlined in Scripps Clinic & Research Foundation v. Genetech,
Inc., 927 F.2d 1565 (Fed. Cir. 1991) (see Final Act. 3–5), concluding that
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Appellant’s Specification “lacks such full, clear, concise and exact terms to
enable any person skilled in the art . . . to make and use the invention
without undue experimentation.” Final Act. 5.
Appellant also references Scripps Clinic, but focuses on the portion
thereof stating:
Open-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. They 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.
Scripps Clinic, 927 F. 2d at 1572; Appeal Br. 4. Appellant contends the
Examiner’s analysis “is improperly guided by the presumption that the
claims do not include an inherent upper limit.” Appeal Br. 4. Instead,
Appellant contends, “[t]he minimum amount of airflow required to operate
the engine provides an inherent practical upper limitation to the claimed
bypass ratio.” Appeal Br. 5; see also Reply Br. 2. Appellant also contends
that one skilled in the art “would understand that the blades 42 and the
flowpaths must fit within the surrounding structure, again, making an
infinite bypass area ratio unachievable.” Appeal Br. 5; see also Reply Br. 1.
Additionally, Appellant references MPEP § 2164.01 which states, “[t]he fact
that experimentation may be complex does not necessarily make it undue, if
the art typically engages in such experimentation.” Appeal Br. 5.
Appellant also references a Board decision addressing a similar
enablement rejection concerning a gas turbine engine, this decision stating:
Although we appreciate the Examiner’s observation that the
open-ended ranges recited in the claims are broad enough to
theoretically encompass numerical values for pressure ratio,
gear reduction ratio, and bypass ratio that may be beyond
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current technological capabilities (see Ans. 2), we agree with
Appellants that one of ordinary skill in the art would
recognize that “the upper limit for each of the claimed
ranges is bounded by known practical structural and
physical limits.”
Ex parte Kohlenberg, Appeal No. 2017-00822 (App. No. 13/340,787,
decided 6/8/2018) (emphasis added); Appeal Br. 6.
Although we are not bound by the holding in Kohlenberg (see Ans. 4),
we find its analysis compelling, along with Appellant’s other contentions
expressed above. Regarding the Wands factors noted by the Examiner,
which address the breadth, nature, state of the art, and level of skill of the
claimed subject matter, the apparatus addressed is a gas turbine engine,
which is a highly complex machine. The Examiner finds that the level of
predictability associated with such a device (another Wands factor) is
“extremely low.” Final Act. 3. We disagree because these complex
machines are highly engineered to exacting standards by very skilled
persons (see above). Thus, although the design and construction of such a
device may take years to complete (i.e., “a design cycle of at least 15 to 25
years”), this long duration does not necessarily reduce the predictability of
the final product, as asserted by the Examiner. See Final Act. 3. Instead,
allowing such skilled persons to work on the product for such a long time
would actually seem to enhance its predictability. Consequently, this and
the other Wands factors (see also Scripps Clinic) would appear to be
contrary to the Examiner’s finding of no enablement.
Further, and specific to the Examiner’s discussion of undue
experimentation (see Final Act. 2–5, Ans. 3–4), it is not clear how the
determination of “a bypass ratio of greater than” a certain number is “undue”
or would involve “undue experimentation” to calculate, even if doing so was
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somewhat complex. See MPEP § 2164.01. Hence, an inherent limit is not
the same as a possible theoretical limit the Examiner seems to address. See
Appeal Br. 4.
Accordingly, and for the reasons expressed above, we do not sustain
the Examiner’s rejection of claims 2, 9, 14–16, 18, 19, and 23–25 as failing
to comply with the enablement requirement.
The rejection of claims 2, 5, 9, 14–16, 18, 19, and 23–25
as being indefinite
The Examiner provides two reasons why these claims are indefinite.
See Final Act. 6–7. The Examiner initially focuses on only those claims that
include a “greater than” limitation (i.e., claims 2, 9, 14–16, 18, 19, 23–25).
See Final Act. 6–7. The Examiner states “‘greater than’ is indefinite as it is
not bounded at its upper limit.” Final Act. 6, 7. The Examiner additionally
focuses on the entire group of rejected claims as reciting “a method of using
the apparatus.” See Final Act. 6–7. The Examiner reasons these claims are
indefinite because such claims contain a “greater than” or a “less than”
limitation (or both), and as such, “[a] single claim which claims both an
apparatus and the method steps of using the apparatus is indefinite.” Final
Act. 6, 7 (referencing In re Katz Interactive Call Processing Patent
Litigation, 639 F.3d 1303 (Fed. Cir. 2011)); see also Ans. 4.
Appellant also addresses both reasons relied upon by the Examiner.
See Appeal Br. 6–8. Regarding the Examiner’s open-ended rationale,
Appellant states that the lack of an upper bound “does not render the claims
indefinite; at most they are broad.” Appeal Br. 6; see also Reply Br. 2
(referencing In re Fisher, 427 F.2d 833 (CCPA 1970) (“the absence of a
limitation ‘does not render the claim indefinite’”). Further, consistent with
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the discussion above regarding enablement, Appellant states, “there are
practical and inherent physical upper limits to the claimed bypass ratios”
thereby not rendering them indefinite. Appeal Br. 7. Appellant also
references Exxon Research & Eng’g Co. v. United States, 265 F.3d 1371,
1375 (Fed. Cir. 2001) (abrogated on other grounds, 134 S. Ct. 2120 (2014))
(see Appeal Br. 7) wherein our reviewing court stated, with respect to that
case, “[t]he claims do not contain any limitation on maximum particle size,
and no limitation is required as a matter of definiteness.” Id. at 1382.
Additionally, we are guided by MPEP § 2173 which states, “[t]he
primary purpose of this requirement of definiteness of claim language is to
ensure that the scope of the claims is clear so the public is informed of the
boundaries of what constitutes infringement of the patent.” See also Ans. 4.
Here, the lack of an upper boundary is no indication the public is unable to
ascertain whether a certain ratio is “greater than” a recited number or not.
Regarding the Examiner’s alternate ‘method and apparatus’ rationale,
with respect to Appellant’s apparatus claims, Appellant states that such
“claims in the present application recite a structural system capability and
not an active method step.” Appeal Br. 8. In other words, “Katz is not
applicable here, as there is no recited user action or any method step in the
claims.” Appeal Br. 8 (emphasis added). With respect to Appellant’s
method claims, our reviewing court has provided guidance that “[m]ethod
claim preambles often recite the physical structures of a system in which the
claimed method is practiced.” Microprocessor Enhancement Corp. v. Texas
Instruments Inc., 520 F.3d 1367, 1374‒75 (Fed. Cir. 2008). In any event,
we are not persuaded that the recitation of either or both a “greater than” or a
“less than” limitation renders that limitation a method step, thereby
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warranting the guidance by our reviewing court discussed in Katz. See also
Reply Br. 2.
Accordingly, and based on the record presented, we do not sustain the
Examiner’s rejection of claims 2, 5, 9, 14–16, 18, 19, and 23–25 as being
indefinite.
The rejection of claims 1, 2, 5, 9, 16, 18, and 19
as unpatentable over Kurzka, Waters, and Lee
Appellant argues these claims (i.e., claims 1, 2, 5, 9, 16, 18, and 19)
together. See Appeal Br. 8–9. We select claim 1 for review, with the
remaining claims standing or falling with claim 1. See 37 C.F.R.
§ 41.37(c)(1)(iv).
Claim 1 recites, “the first compressor section includes three stages”
and also, “the low pressure turbine section having a greater number of stages
than the first compressor section.”2
The Examiner primarily relies on the teachings of Kurzka (referencing
column 4 of Table 2 thereof) but indicates that Kurzka does not teach “using
3 first compressor stages, wherein there are more LPT stages than first
compressor stages.”3 Final Act. 8–9. The Examiner relies on Paragraph 55

2 Regarding the scope of the recited “first compressor section,” Appellant’s
specification provides guidance that “[a]ir entering the compressor section is
compressed and delivered into the combustion section.” Spec. ¶ 2. We thus
understand “first compressor section” as being where air is compressed prior
to its use for combustion.
3 We note, however, that column 1 of Table 2 of Kurzka discloses
employing “3” booster stages and “5” LPT stages. Kurzka, page 152. We
further note that Kurzka teaches, “[t]he single stage fan is followed by a
number of booster stages with a combined pressure ratio of 2.8.” Kurzka,
page 147. Hence, we understand air enters the booster stages and is further
compressed, consistent with the recited “first compressor section.”
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of Lee for teaching “increasing the number of turbine stages in a gas turbine
engine.” Final Act. 9.
Appellant contends, “Lee does not teach increasing the number of
turbine stages” and “[t]he Examiner has not identified any part of Lee that
teaches increasing turbine stage counts.” Appeal Br. 9; see also Reply Br. 2.
To be clear, Paragraph 55 of Lee states, “the turbine stages decrease pressure
and temperature of the combustion gas for extracting energy therefrom.”
See also Ans. 4. Based on this teaching of turbine stages extracting energy
from the combustion gas, the Examiner explains, “increasing the number of
turbine stages will further [permit] extracting more energy from the
combustion gas.” Ans. 4. Appellant challenges this increase in the number
of turbine stages because of the additional weight this will entail. See
Appeal Br. 9; Reply Br. 2–3. However, Kurzka teaches that “the weight
penalty for the 9 stage LPT is not as large as might be expected.” Kurzka,
page 148; see also Ans. 5. Thus, if the weight penalty for a nine-stage LPT
is not so large, then it follows that the weight penalty for a fewer number of
stages (but more than 3) would be even less. In view of such teachings, we
are not persuaded that “Kurzk[a] teaches away” from increasing turbine
stage count as Appellant contends. Appeal Br. 9 (“Kurzk[a] notes that there
is a weight penalty for higher stage counts” and “weight increase is against
convention[al] wisdom”); see also Ans. 5, 6.
Accordingly, and based on the record presented, we are not persuaded
the Examiner relied on “impermissible hindsight reconstruction” or that
“[t]he Examiner has not made a prima facie case of obviousness” as
Appellant argues. Appeal Br. 9; Reply Br. 3. We sustain the Examiner’s
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rejection of claims 1, 2, 5, 9, 16, 18, and 19 as unpatentable over Kurzka,
Waters, and Lee.
The rejection of claims 7, 8, and 21–25
as unpatentable over Kurzka, Waters, Lee, and White
Appellant does not present separate arguments to rebut this rejection.
See Appeal Br. 9–10. Appellant, instead, states, “[t]he addition of the
teachings of White does not overcome the above noted deficiencies with
respect to Kurzka, Waters, and Lee and base claim 1.” Appeal Br. 10.
Accordingly, we also sustain the Examiner’s rejection of claims 7, 8, and
21–25 as being obvious over Kurzka, Waters, Lee, and White.
CONCLUSION
In summary:
Claims
Rejected
35 U.S.C. § Reference(s)/Basis Affirmed Reversed
2, 9, 14–
16, 18, 19,
23–25
112 ¶ 1 Enablement 2, 9, 14–16,
18, 19, 23–
25
2, 5, 9,
14–16, 18,
19, 23–25
112 ¶ 2 Indefinite 2, 5, 9, 14–
16, 18, 19,
23–25
1, 2, 5, 9,
16, 18, 19
103(a) Kurzka, Waters,
Lee
1, 2, 5, 9,
16, 18, 19

7, 8, 21–
25
103(a) Kurzka, Waters,
Lee, White
7, 8, 21–25
Overall
Outcome4
1, 2, 5, 7–9,
16, 18, 19,
21–25
14, 15

4 37 C.F.R. § 41.50(a)(1) states: “The affirmance of the rejection of a claim
on any of the grounds specified constitutes a general affirmance of the
decision of the examiner on that claim.”
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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 IN PART