United Technologies Corporation

Patent Trials and Appeals Board

Sep 16, 2021

2021002148 (P.T.A.B. Sep. 16, 2021)

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.
15/175,073 06/07/2016 Michael Ronan 90578US02;
67097-3253PUS1
3886
54549 7590 09/16/2021
CARLSON, GASKEY & OLDS/PRATT & WHITNEY
400 West Maple Road
Suite 350
Birmingham, MI 48009
EXAMINER
MALATEK, KATHERYN A
ART UNIT PAPER NUMBER
3741
NOTIFICATION DATE DELIVERY MODE
09/16/2021 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 MICHAEL RONAN
____________

Appeal 2021-002148
Application 15/175,073
Technology Center 3700
____________

Before BRETT C. MARTIN, JEREMY M. PLENZLER, and
LISA M. GUIJT, Administrative Patent Judges.

GUIJT, Administrative Patent Judge.

DECISION ON APPEAL

STATEMENT OF THE CASE
Appellant1 seeks our review under 35 U.S.C. § 134(a) of the rejection
of claims 1, 3, 5–10, 12–18, and 23–27 under 35 U.S.C. § 103 as
unpatentable over Negulescu2 and Breeze-Stringfellow.3 We have
jurisdiction under 35 U.S.C. § 6(b).
We REVERSE.

1 We use the word “Appellant” to refer to “applicant” as defined in 37
C.F.R. § 1.42. Appellant identifies Raytheon Technologies Corporation as
the real party in interest. Appeal Br. 1.
2 US 2010/0215481 A1; published Aug. 26, 2010.
3 US 6,325,595 B1; issued Dec. 4, 2001.
Appeal 2021-002148
Application 15/175,073
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THE INVENTION
Appellant’s invention relates to “cooling of gas turbine engine
components, and more particularly to modulation of cooling airflow.” Spec.
2. Claims 1 and 10 are the independent claims on appeal. Claim 1,
reproduced below, is illustrative of the subject matter on appeal.
1. A cooling arrangement for a gas turbine engine, comprising:
an offtake duct including an offtake inlet coupled to a cooling
source, the offtake duct defining a throat;
a valve downstream of the throat, the valve coupling the
offtake duct and a first cooling flow path, the valve operable to
selectively modulate flow through the offtake duct;
a bleed passage including a bleed inlet coupling the offtake
duct and a second cooling flow path, the bleed inlet defined at a
location between the offtake inlet and the throat, inclusive; and
wherein the cooling source is a bypass flow path defined by a
fan nacelle.
OPINION
Independent claim 1 and dependent claims 3 and 5–9
Regarding independent claim 1, the Examiner finds that Negulescu
discloses a cooling arrangement, comprising: (i) an offtake duct including
an offtake inlet coupled to a cooling source (i.e., nozzle 5 within bypass flow
3); (ii) a valve coupling the offtake duct and a first cooling flow path, the
valve operable to selectively modulate flow through the offtake duct (i.e.,
control valve 6); and (iii) and a bleed passage including a bleed inlet
coupling the offtake duct and a second cooling flow path (i.e., branching-off
channel of cooling-air duct 9) as required by claim 1. Final Act. 2–3 (citing
Negulescu ¶¶ 2, 13, Fig. 1); see also Negulescu ¶¶ 20, 21. The Examiner
provides an annotated Figure 1 of Negulescu, reproduced below. Final Act.
4.
Appeal 2021-002148
Application 15/175,073
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The Examiner’s annotated Figure 1 of Negulescu depicts “a schematic
partial sectional view in the axial direction [of an aircraft gas turbine]”
(Negulescu ¶ 15), wherein the Examiner identifies an offtake inlet at airflow
arrow 4 of inlet nozzle 5 and also a bleed inlet at the intersection of nozzle 5
and the inlet end of cooling-air duct 9.
The Examiner finds that Negulescu’s nozzle 5 (or offtake duct) fails
to define a throat, as required by claim 1, and the Examiner relies on Breeze-
Stringfellow for teaching an offtake duct (i.e., slot 52) defining a throat (i.e.,
second throat 136) and having a bleed inlet included at throat 136 (i.e.,
apparently domestic bleed portion 66’s inlet located at second throat area
148). Final Act. 3 (citing Breeze-Stringfellow, Fig. 8). The Examiner
reasons that it would have been obvious
[to incorporate] the features of Breeze-Stringfellow . . . into
[Negulescu’s cooling arrangement] to include the offtake duct
[(i.e., nozzle 5)] defining a throat; the valve being downstream
of the throat, and the bleed inlet defined at a location between the
offtake inlet and the throat[, inclusive] . . . to limit the maximum
Appeal 2021-002148
Application 15/175,073
4
amount of air flowing through the offtake duct as suggested and
taught by Breeze-Stringfellow.
Id. (citing Breeze-Stringfellow 2:14–18); Ans. 18 (citing Breeze-
Stringfellow 4:38–43). The Examiner also explains that
Breeze-Stringfellow discloses that the second throat area of the
second throat 136 is sized to define the maximum flow from the
offtake duct 52 into bleed passage 66 and at that maximum flow
to prevent flow separation along the aft surface of the annular
slot 174, which is just upstream of throat 136.
Ans. 16 (citing Breeze-Stringfellow 2:14–18, 4:38–43). The Examiner finds
that “[a]s is known in the art, flow separation causes wakes and vortices,
making the flow more turbulent.” Id.
Appellant argues that “the Examiner’s rationale hinges upon a result
of the combination rather than a reason for making the Examiner’s proposed
modification,” which we understand as an allegation of an improper use of
hindsight. Appeal Br. 4. In support, Appellant submits that the Examiner
“does not provide any justification as to why one of ordinary skill in the art
would be motivated to limit airflow through Negulescu’s disclosed
arrangement.” Appeal Br. 4; see also Reply Br. 2. Appellant also submits
that the Examiner does not “point to any objective evidence that Negulescu’s
control valve 6 is incapable of limiting flow” or that “a maximum amount of
bleed flow extracted by the uncontrolled cooling-air 9 of Negulescu would
cause separation along the inlet nozzle 5 at a position between the
uncontrolled cooling-air duct 9 and control valve 6.” Reply Br. 3–4.
Appellant submits that Negulescu discloses that “control valve 6 ‘enables
the cooling air flow to be adjusted in an optimum manner.’” Id. at 4
(quoting Negulescu ¶ 13).
The Specification discloses that “offtake duct 78 can be configured
such that flow at the throat 82 has a static pressure equal to or less than a
Appeal 2021-002148
Application 15/175,073
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local static pressure of the bypass flow path B when the valve 72 is located
in a fully open position.” Spec. ¶ 48. The Specification further discloses
that
[b]y defining the bleed inlet 88 adjacent to the throat 82, a
pressure of the flow F2 through the secondary cooling flow path
P2 can be substantially equal to a static pressure of the bypass
flow path B when the valve 72 is located in the open position,
and can be substantially equal to a total pressure of the bypass
flow path B when the valve 72 is located in the closed position.
Id. ¶ 51. Thus, the throat appears designed to manage the pressure of the
airflow within bleed passage 86 (i.e., flow F2 through the secondary cooling
flow path P2) relative to the upstream local static pressure of bypass flow
path B and the downstream position of valve 72.
Similar to the present invention, Negulescu, as depicted supra, has an
offtake duct (or inlet nozzle 5) with a control valve 6 downstream of the
bleed passage inlet (or inlet of cooling-air duct 9). As argued by Appellant,
Negulescu discloses that control valve 6 adjusts cooling air flow in an
optimum manner for the cooling arrangement: “[the] control valve . . . can
be actuated . . . [to] enable[] the cooling air flow to be adjusted in an
optimum manner.” Negulescu ¶ 13. Negulescu also discloses that the air
flow in the cooling-air duct (i.e., the bleed passage) is uncontrolled:
“airflow 4 entering via the inlet nozzle 5 is routed radially inwards towards a
branching-off channel of a direct, uncontrolled cooling-air duct 9 and to a
control valve 6.” Negulescu ¶ 20.
Breeze-Stringfellow’s bleed assembly is distinguishable from the
claimed invention and Negulescu, in that the bleed passage, as relied on by
the Examiner (i.e., domestic bleed portion 66), is downstream of a first
cooling path (i.e., customer bleed portion 68), such that second throat 136 is
Appeal 2021-002148
Application 15/175,073
6
also downstream of the first cooling path. Breeze-Stringfellow discloses,
with reference to Figures 2–5 and 8, that
second throat area 148 of the second throat 136 is sized such that
during operation with a maximum amount of the customer bleed
flow portion 68 being extracted the diffusion in the domestic
bleed flow is not excessive i.e there is no separation in the
annular slot 52 along the aft surface 174 of the annular slot. The
second throat area 148 is always less than the first throat area
142.
Breeze-Stringfellow 4:38–44; see also id. at 2:13–18. Thus, Breeze-
Stringfellow appears to include second throat 136 to address air flow
separation within the offtake duct due to a maximum airflow extracted into
customer bleed portion 68 upstream of domestic bleed portion 66.
In view of the differences between the cooling arrangements of
Negulescu and Breeze-Stringfellow, and Negulescu’s teachings regarding
the valve’s function to optimize system flow and the allowance of an
uncontrolled flow into the bleed passage, we agree with Appellant that the
Examiner has not provided sufficient support as to why a person of ordinary
skill in the art would be motivated to design a throat in inlet nozzle 5,
wherein cooling-air duct 9 is at a location between the offtake inlet and the
throat, inclusive. In other words, we agree with Appellant that the Examiner
has failed to support that an air flow separation is of concern in Negulescu,
for example, where (unlike Breeze-Stringfellow) the bleed passage is
upstream of the first or primary cooling path. We “cannot use hindsight
reconstruction to pick and choose among isolated disclosures in the prior art
to deprecate the claimed invention.” In re Fine, 837 F.2d 1071, 1075 (Fed.
Cir. 1988).
Accordingly, we do not sustain the Examiner’s rejection of
independent claim 1, and claims 3 and 5–9 depending therefrom. The
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Application 15/175,073
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Examiner relies on the same deficient findings relative to independent claim
10.
Independent claim 10 and dependent claims 12–18 and 23–27
Although independent claim 10 does not specify the location of the
valve relative to the throat as in independent claim 1, we find that the
Examiner’s reliance on Breeze-Stringfellow’s teachings relative to second
throat 136 is insufficient to support the Examiner’s proposed modification to
Negulescu’s cooling-air channel 9, to have an inlet defined at a location
between the offtake inlet and a throat, inclusive, as required by claim 10, for
the reasons stated supra. Final Act. 8–9.
Accordingly, we do not sustain the Examiner’s rejection of
independent claim 10 and claims 12–18 and 23–27.

CONCLUSION
The Examiner’s decision rejecting claims 1, 3, 5–10, 12–18, and 23–
27 is reversed.
DECISION SUMMARY
In summary:
Claim(s)
Rejected
35
U.S.C.
§
Reference(s)/Basis Affirmed Reversed
1, 3, 5–10,
12–18, 23–
27
103 Negulescu, Breeze-
Stringfellow
1, 3, 5–
10, 12–
18, 23–27

REVERSED