Rolls-Royce North American Technologies, Inc.

Patent Trials and Appeals Board

Feb 12, 2021

2020002260 (P.T.A.B. Feb. 12, 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.
15/437,485 02/21/2017 Michael James Armstrong 1106-238US01/LWA11573 3899
120486 7590 02/12/2021
Shumaker & Sieffert, P.A.
Rolls-Royce Corporation
1625 Radio Drive
Suite 100
Woodbury, MN 55125
EXAMINER
DINH, THAI T
ART UNIT PAPER NUMBER
2846
NOTIFICATION DATE DELIVERY MODE
02/12/2021 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):
pairdocketing@ssiplaw.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte MICHAEL JAMES ARMSTRONG and
MARK JON BLACKWELDER
Appeal 2020-002260
Application 15/437,485
Technology Center 2800
Before LINDA M. GAUDETTE, CHRISTOPHER C. KENNEDY, and
JANE E. INGLESE, Administrative Patent Judges.
GAUDETTE, Administrative Patent Judge.

DECISION ON APPEAL1

The Appellant2 appeals under 35 U.S.C. § 134(a) from the Examiner’s
decision finally rejecting claims 1, 3–7, 9, 11, 13, and 17–20.3

1 The appeal record includes the following documents: Specification filed
Feb. 21, 2017 (“Spec.”); Final Office Action dated Jan. 23, 2019(“Final
Act.”); Appeal Brief filed July 15, 2019 (“Appeal Br.”); Claims Appendix
filed Aug. 22, 2019 (“Claims App.”); Examiner’s Answer dated Nov. 26,
2019 (“Ans.”); and Reply Brief filed Jan. 27, 2020 (“Reply Br.”).
2 The term “Appellant” refers to “applicant” as defined in 37 C.F.R.
§ 1.42. The Appellant identifies the real party in interest as Rolls-Royce
North American Technologies, Inc. Appeal Br. 3.
3 We have jurisdiction under 35 U.S.C. § 6(b).
Appeal 2020-002260
Application 15/437,485

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We REVERSE.
CLAIMED SUBJECT MATTER
The invention “relates to techniques for controlling turboelectric
distributed propulsion (TeDP) systems.” Spec. ¶ 2. Of the appealed claims,
claims 1, 7, and 17 are independent. Claim 1, reproduced below, is
illustrative of the claimed subject matter:
1. A propulsion system, comprising:
an electrical bus;
a generator configured to provide electrical power to the
electrical bus;
a propulsor configured to provide thrust by
simultaneously being driven by the electrical power at the
electrical bus; and
a controller configured to:
synchronize a rotational speed of the propulsor
with a rotational speed of the generator after the
propulsor has become unsynchronized with the rotational
speed of the generator by disengaging the propulsor from
the electrical bus prior to controlling at least one of: the
rotational speed of the generator, nozzle area of the
propulsor, and a pitch angle of the propulsor.
Claims App. 3.
REJECTIONS
1. Claims 1 and 3–5 are rejected under 35 U.S.C. § 102(a)(l) as
anticipated by Kilgore (US 4,338,525, issued July 6, 1982). Final Act. 2–5.

Appeal 2020-002260
Application 15/437,485

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2. Claim 6 is rejected under 35 U.S.C. § 103 as unpatentable over
Kilgore in view of Barnes (US 3,066,741, issued Dec. 4, 1962). Final Act.
5–6.
3. Claims 7, 9, 11, 13 and 17–20 are rejected under 35 U.S.C.
§ 103 as being unpatentable over Barnes in view of Kilgore. Final Act. 6–14.
OPINION
Independent claims 1 and 17 recite systems that include, respectively,
“a controller configured to . . . disengag[e]” and “means for disengaging” a
propulsor from an electrical bus positioned between the propulsor and a
generator. See Claims App. 3, 8. Independent claim 7 recites a method that
includes a step of disengaging a propulsor from an electrical bus shared
between a plurality of propulsors and a generator. Id. at 5. As further
discussed below, the Examiner found that Kilgore discloses or suggests
these independent claim limitations. See Final Act. 3, 7, 9.
Referring to the propulsion system illustrated in Kilgore’s Figure 1,
the Examiner found that the line connecting the output of generator 12 to the
input of motor 16 is an electrical bus positioned between a propulsor (the
combination of motor 16, shaft 26, and propeller 24) and generator 12. See
Final Act. 2–3, 7. The Examiner found that when Kilgore’s switchgear 18 is
open and switchgear 20 is closed, the propulsor is disengaged from the
electrical bus. Id. at 3, 7 (citing Kilgore, Figs. 1, 2, col. 5, ll. 19–57, col. 6, l.
47–col. 7, l. 22). The Appellant argues that Kilgore’s propulsor is never
disengaged from the electrical bus, because “the motor and propeller
continuously receive electrical power from generator 12 whether directly
connected to generator 12 through switchgear 18 or indirectly connected to
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Application 15/437,485

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generator 12 through frequency converter 22 and switchgear 20.” Appeal
Br. 7.
The Examiner’s and the Appellant’s respective positions raise an issue
as to the meaning of the claim 1 limitation “disengaging the propulsor from
the electrical bus,” and the similar limitations in claims 7 and 17. The
Specification discloses that “[c]ontroller 112 may disengage the individual
propulsor from an electrical bus shared between the plurality of propulsors
and the generator.” Spec. ¶ 40. “For example, controller 112 may send a
signal to isolation device 105A that brings propulsor 106A offline by
causing isolation device 105A to prevent motor 108A from receiving
electrical current from AC generator 102.” Id. “With propulsor 106A offline,
propulsor fan 110A may be allowed to windmill as the other propulsors
106B–106N remain online and providing thrust to system 100.” Id. The
descriptions in paragraphs 51 and 53, and in Figure 2 similarly indicate that
the claim limitations relating to disengaging the propulsor from the electrical
bus require isolating the propulsor from electrical power produced by the
generator.
As noted by the Appellant, Appeal Br. 7, Kilgore discloses that
“[w]ith switchgear 18 closed and switchgear 20 opened, the generator 12 is
electrically connected directly to the motor 16,” Kilgore 5:27–29.
“Alternately, with switchgear 18 opened and switchgear 20 closed, the
generator 12 is electrically connected to the motor 16 through the frequency
converter 22.” Id. at 5:29–32. Kilgore further indicates that motor 16 (and,
therefore, the propulsor) is always electrically connected to generator 12: “It
is anticipated that, during transition from one connection mode to the other,
both switchgear means 18 and 20 will temporarily be closed simultaneously
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Application 15/437,485

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so as to guarantee continuity between the generator 12 and the motor 16.” Id.
at 5:32–36; see Appeal Br. 7.
In view of the foregoing, we determine that the Examiner reversibly
erred in finding that Kilgore discloses or suggests the “disengaging”
limitations of independent claims 1, 7, and 17. Accordingly, we do not
sustain the rejections of claims 1, 3–7, 9, 11, 13, and 17–20.

DECISION SUMMARY
Claims
Rejected
35 U.S.C. § Reference(s)/Basis  Affirmed Reversed
1, 3–5 102(a)(1) Kilgore 1, 3–5
6 103 Kilgore, Barnes 6
7, 9, 11, 13,
17–20
103 Barnes, Kilgore 7, 9, 11,
13, 17–20
Overall
Outcome:

1, 3–7, 9,
11, 13, 17–
20
REVERSED