Hamilton Sundstrand Corporation

Patent Trials and Appeals Board

Nov 17, 2021

2020006800 (P.T.A.B. Nov. 17, 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.
15/968,209 05/01/2018 John A. Dickey 102014US01-U74-012829 6032
113529 7590 11/17/2021
Kinney & Lange, P.A.
312 South Third Street
Minneapolis, MN 55415
EXAMINER
GBLENDE, JEFFREY A
ART UNIT PAPER NUMBER
2838
NOTIFICATION DATE DELIVERY MODE
11/17/2021 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):
USPatDocket@kinney.com
amkoenck@kinney.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte JOHN A. DICKEY
Appeal 2020-006800
Application 15/968,209
Technology Center 2800
Before JEFFREY T. SMITH, LINDA M. GAUDETTE, and
JAMES C. HOUSEL, Administrative Patent Judges.
SMITH, 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, 5–11, and 14–21. We have
jurisdiction 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(a). Appellant identifies the real party in interest as United
Technologies Corporation, which directly or indirectly owns the entire
equity in Hamilton Sundstrand Corporation. (Appeal Br. 2.)
Appeal 2020-006800
Application 15/968,209
2
CLAIMED SUBJECT MATTER
Appellant’s invention is directed to a method of controlling switches
in a power converter. Claim 1, reproduced below, is illustrative of the
claimed subject matter on appeal:
1. A method of controlling a power converter that
includes at least one first switch of a first switch type, wherein
the first switch type is a low gate charge field effect transistor,
and at least one second switch of a second switch type, where in
the second switch type is a low on-resistance field effect
transistor, the method comprising:
converting, by the power converter, an input power at a
converter input into output power at a converter output for a
load, wherein converting the input power into the output power
comprises:
turning on, by a controller, the at least one first switch to
conduct current from the converter input to the converter
output; and
turning on, by the controller, the at least one second
switch to conduct current from the converter input to the
converter output after a first threshold time period following
turn-on of the at least one first switch.
Appeal Br. 10, Claims App.
The following rejections are presented for our review:
I. Claims 1, 2, 5, 6, 10, 11, 14, 15, 19, and 20 were rejected under 35
U.S.C. § 103 unpatentable over the combination of Elbanhawy (US
2003/0038615 A1, published Feb. 27, 2003) in view of Sawtell (US
2007/0070659 A1, published Mar. 27, 2007) and Disney (US 2013/0032895
A1, published Feb. 7, 2013).
II. Claims 7–9, 16–18, and 21 were rejected under 35 U.S.C. § 103 as
being unpatentable over the combination of Elbanhawy, Sawtell, Disney,
and Dickey (US 2015/0364922 A1, published Dec. 17, 2015).
Appeal 2020-006800
Application 15/968,209
3
OPINION
We review the appealed rejections for error based upon the issues
Appellant identifies, and in light of the arguments and evidence produced
thereon. See In re Jung, 637 F.3d 1356, 1365 (Fed. Cir. 2011) (“[I]t has
long been the Board’s practice to require an applicant to identify the alleged
error in the examiner’s rejections . . . .” (citing Ex parte Frye, 94 USPQ2d
1072, 1075 (BPAI 2010) (precedential))).
Appellant has presented arguments addressing only independent
claims 1, 10, and 19 together as a group. Appellant does not present
substantive arguments addressing dependent claims 2, 5, 6, 11, 14, 15, and
20. We select claim 1 as representative of the rejected subject matter.
Upon consideration of the evidence in this appeal record in light of the
respective positions advanced by the Examiner and Appellant, we determine
that Appellant has not identified reversible error in the Examiner’s
determination that the subject matter recited in independent claims 1, 10, and
19 would have been obvious to one of ordinary skill in the art within the
meaning of 35 U.S.C. § 103. We are in complete agreement with the
Examiner’s reasoned analysis and application of the prior art. We add the
following for emphasis only.
The complete statement of the rejections on appeal appears in the
Final Office Action. (Final Act. 2–10.)
Appellant argues that the Elbanhawy, Sawtell, and Disney references
fail to teach or suggest a combination of two types of switches in parallel in
a power converter circuit in which the first switch type is a low gate field
effect transistor and the second switch type is a low on-resistance field effect
transistor as recited in independent claims 1, 10, and 19. (Appeal Br. 4–8.)
Appellant argues the Examiner’s stated motivation—to improve operational
Appeal 2020-006800
Application 15/968,209
4
efficiencies—is only a “superficial cover to the use of impermissible
hindsight.” (Appeal Br. 8.)
The Examiner finds Elbanhawy teaches a method of controlling a
power converter that includes at least one first switch Q1 of a first switch
type (Q1 is optimized to reduce dynamic loss) and at least one second switch
Q2 of a second switch type (Q2 is optimized to reduce conduction loss).
(Final Act. 2–3; Elbanhawy ¶ 30.) Elbanhawy teaches transistors Q1 and Q2
are parallel connected between two terminals. (Elbanhawy ¶ 30.) The
Examiner finds Elbanhawy does not disclose that the first switch type is a
low gate charge field effect transistor and that the second switch type is a
low on-resistance field effect transistor. (Final Act. 3.) As found by the
Examiner (id. at 3–4), Sawtell teaches a first switch type that is a low gate
charge field effect transistor that improves operational efficiency and Disney
teaches a second switch type that is a low on-resistant field-effect transistor
that improves operational efficiency (Sawtell ¶ 33; Disney ¶ 2). The
Examiner determines that it would have been obvious to perform the method
described by Elbanhawy utilizing a first switch type such as described by
Sawtell and a second switch type such as described by Disney to improve
the operational efficiency. (Final Act. 3–4.)
Appellant’s arguments (Appeal Br. 4–8) are not persuasive of
reversible error in the Examiner’s obviousness determination. Elbanhawy,
Sawtell, and Disney are each directed to power converter circuits comprising
switches. Elbanhawy describes a method and circuitry for implementing a
more efficient DC-DC converter that utilizes first and second switches.
(Elbanhawy ¶¶ 4, 6.) Elbanhawy does not limit the type of switches
employed. Sawtell and Disney are directed to power converter circuits
comprising switches. Sawtell teaches a power converter circuit comprising a
Appeal 2020-006800
Application 15/968,209
5
low gate field effect transistor (first switch type) that is a low gate charge
field effect transistor that improves operational efficiency and Disney
teaches a power converter circuit comprising a low on-resistance field effect
transistor (second switch type) that enhances operational stability. A person
of ordinary skill in the art would have reasonably looked to known
transistors employed in power converter circuits for utilization in
Elbanhawy’s method. Accordingly, we are of the opinion that one of
ordinary skill in this art, routinely following the teachings of the references
as combined by the Examiner, would have reasonably arrived at the claimed
method of controlling a power converter encompassed by claims 1, 10, and
19 without resort to Appellant’s Specification. See, e.g., KSR Int’l Co. v.
Teleflex Inc., 550 US 417, 418 (2007) (“[A]nalysis [of whether the subject
matter of a claim would have been obvious] need not seek out precise
teachings directed to the specific subject matter of the challenged claim, for
a court can take account of the inferences and creative steps that a person of
ordinary skill in the art would employ.”); In re Translogic Tech. Inc., 504
F.3d 1249, 1260 (Fed. Cir. 2007) (“[A] flexible approach to the [teaching,
suggestion, or motivation to combine] test prevents hindsight and focuses on
evidence before the time of invention without unduly constraining the
breadth of knowledge available to one of ordinary skill in the art during the
obviousness analysis.” (citations omitted)); In re Kahn, 441 F.3d 977, 985-
88 (Fed. Cir. 2006); In re Keller, 642 F.2d 413, 425 (CCPA 1981) (“[T]he
test [for obviousness] is what the combined teachings of the references
would have suggested to those of ordinary skill in the art.”); In re Sovish,
769 F.2d 738, 743 (Fed. Cir. 1985) (skill is presumed on the part of one of
ordinary skill in the art); In re Bozek, 416 F.2d 1385, 1390 (CCPA 1969)
(“Having established that this knowledge was in the art, the examiner could
Appeal 2020-006800
Application 15/968,209
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then properly rely, as put forth by the solicitor, on a conclusion of
obviousness ‘from common knowledge and common sense of the person of
ordinary skill in the art without any specific hint or suggestion in a particular
reference.’”); see also In re O’Farrell, 853 F.2d 894, 903–04 (Fed. Cir.
1988) (“For obviousness under § 103, all that is required is a reasonable
expectation of success.” (citations omitted)).
Appellant fails to explain adequately why one skilled in the art, using
no more than ordinary creativity, would not have been able to arrive at the
claimed invention from the teachings of the cited art. Appellant has not
directed us to evidence of unexpected results to support the patentability of
the claimed method of controlling a power converter (claims 1 and 10) and
power converting system (claim 19).
Accordingly, we affirm the Examiner’s prior art rejection of claims 1,
2, 5, 6, 10, 11, 14, 15, 19, and 20 under 35 U.S.C. § 103 for the reasons the
Examiner presents and we give above.
Although an additional reference is applied in the rejection of claims 7–9,
16–18, and 21, Appellant does not provide a substantive argument as to the
separate patentability of these claims but, rather, argues that the additional
reference does not remedy the deficiency in the references applied to independent
claims 1 and 10. (Appeal Br. 8.) Appellant does not provide a substantive
argument establishing error in the reason the Examiner cited Dickey. Because we
do not find Appellant’s arguments persuasive as to independent claims 1 and 10, it
follows that these arguments are unpersuasive as to claims 7–9, 16–18, and 21.

Appeal 2020-006800
Application 15/968,209
7
CONCLUSION
The Examiner’s decision to reject claims 1, 2, 5–11, and 14–21 is
affirmed.

DECISION SUMMARY
In summary:
Claims
Rejected
35 U.S.C.
§
Reference(s)/Basis Affirmed Reversed
1, 2, 5, 6,
10, 11, 14,
15, 19, 20
103 Elbanhawy,
Sawtell, Disney
1, 2, 5, 6,
10, 11, 14,
15, 19, 20

7–9, 16–18,
21
103 Elbanhawy,
Sawtell, Disney,
Dickey
7–9, 16–18,
21

Overall
Outcome
1, 2, 5–11,
14–21

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