Ex Parte El-Refaie et al

Patent Trial and Appeal Board

Aug 25, 2016

12949882 (P.T.A.B. Aug. 25, 2016)

UNITED STA TES p A TENT AND TRADEMARK OFFICE
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR
12/949,882 11/19/2010 Ayman Mohamed Fawzi El-Refaie
131278 7590 08/29/2016
GE Ventures- Licensing
C/O Meagher Emanuel Laks Goldberg & Liao, LLP
One Palmer Square, Suite 325
Princeton, NJ 08542
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
ATTORNEY DOCKET NO. CONFIRMATION NO.
243942-1 6655
EXAMINER
GLASS, ERICK DAVID
ART UNIT PAPER NUMBER
2837
NOTIFICATION DATE DELIVERY MODE
08/29/2016 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):
vivian.brandon@ge.com
gpo.mail@ge.com
gedocket@meagheremanuel.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte AYMAN MOHAMED FAWZI EL-REFAIE and
ROBERT DEAN KING
Appeal2014-009768
Application 12/949,882
Technology Center 2800
Before TERRY J. OWENS, MICHAEL P. COLAIANNI, and
JEFFREY R. SNAY, Administrative Patent Judges.
COLAIANNI, Administrative Patent Judge.
DECISION ON APPEAL
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Application 12/949,882
Appellants appeal under 35 U.S.C. § 134 the final rejection of claims
1-23 1. We have jurisdiction over the appeal pursuant to 35 U.S.C. § 6(b ).
We REVERSE.
Appellants' invention is directed to induction motors having a low
leakage inductance and to a method and system for designing low-
inductance, high-efficiency induction machines by providing power
converters that include silicon carbide metal-oxide-semiconductor field
effect transistors (MOS FE Ts) (Spec. i-f 1 ).
Claims 1 and 8 are illustrative:
1. An electric drive system comprising:
an induction machine;
a power converter electrically coupled to the induction
machine to drive the induction machine, the power converter
comprising a plurality of silicon carbide (SiC) switching
devices; and
a controller electrically coupled to the power converter
and programmed to transmit switching signals to the plurality
of SiC switching devices at a given switching frequency such
that a peak-to-peak current ripple is less than approximately
five percent.
8. A method of manufacturing an electric drive system
comprising the steps of:
providing an induction machine having a given leakage
inductance;
providing a silicon carbide (SiC) power converter having
a plurality of SiC switching devices, wherein the SiC power
converter is coupleable a power source;
providing a controller, wherein the controller is
programmed [to] transmit switching signals to the plurality of
SiC switching devices at a rate that minimizes a current ripple
1 Claim 24 is pending and was objected to by the Examiner as dependent
upon a rejected base claim but would be allowable if rewritten in
independent form (Final Act. 10).
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Application 12/949,882
capable of being generated due to the given leakage inductance
of the induction machine; and
coupling the SiC power converter to the induction
machine to drive the induction machine and to the controller.
App. Br. 14 and 15 (Claims Appendix).
Appellants appeal the following rejections:
1. Claims 1-7 are rejected under 35 U.S.C. § 103(a) as unpatentable over
Kusase (US 5,543,703, issued August 6, 1996) in view of Boules (US
6,498,451 Bl, issued December 24, 2002).
2. Claims 8-10, and 12-17 are rejected under 35 U.S.C. § 103(a) as
unpatentable over Kusase in view of Nilson (US 7 ,218,021 B2, issued
May 15, 2007).
3. Claims 11 and 18 are rejected under 35 U.S.C. § 103(a) as
unpatentable over Kusase in view of Nilson and Boules.
4. Claims 19-23 are rejected under 35 U.S.C. § 103(a) as unpatentable
over Kusase in view of Nilson and Flett (US 2006/0152085 Al,
published July 13, 2006).
FINDINGS OF FACT & ANALYSIS
REJECTION (1)
Appellants argue that the Examiner has not established that Boules
teaches a controller electrically coupled to the power converter and
programmed to transmit switching signals to the plurality of SiC switching
devices at a given switching frequency such that a peak-to-peak current
ripple is less than approximately five percent as recited in claim 1 (App. Br.
6). Appellants argue that Boules teaches controlling voltage waveforms so
that the torque ripple is kept below 3%. Id. Appellants contend that the
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Application 12/949,882
Examiner has not provided any evidence to substantiate the unsupported
finding that "torque is directly proportional to current, therefore if [the]
magnitude of one is less than 5%, so is the other" (Final Act. 1 O; App. Br.
4).
The Examiner's findings and conclusions regarding Kusase and Boule
are located on pages 2 to 3 of the Final Action. Regarding Appellants'
argument that the Examiner has not provided any evidence to substantiate a
direct proportionality of current ripple and torque ripple, the Examiner
responds that column 4, lines 43--44 of Boules establishes that torque is
proportional to current (Ans. 2).
Boules at column 4, lines 41--44 discloses that "the commutation
torque ripple results from the interaction of the harmonic contents of the
stator currents and rotor field, as the instantaneous torque is proportional to
the product of the stator current and induced voltage." Although, Boules
teaches that torque is proportional to the product of stator current and
induced voltage, the Examiner has not established that torque and current are
"directly" proportional. The Examiner has not provided evidence sufficient
to establish that current ripple and torque ripple are directly proportional
such that "if [the] magnitude of one is less than 5%, so is the other" (Final
Act. 10). The Examiner has not established the exact proportional
relationship between current ripple and torque ripple. Therefore, the
Examiner's extrapolation of Boules' teaching that the torque ripple should
be less than 3% to include less than 3% current ripple lacks evidentiary
support and rational underpinning.
The Examiner has not dispensed with the initial burden of showing
where all the claim limitations are taught or suggested by Kusase and
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Application 12/949,882
Boules. On this record, we are constrained to reverse the Examiner's
§ 103(a) rejection over Kusase and Boules.
REJECTIONS (2) TO (4)
Appellants argue that Nilson does not provide any disclosure related
to reducing current ripple as claimed (App. Br. 9). Appellants contend that
Nilson's teachings are directed to reducing torque ripple and cogging ripple,
not current ripple as required by claims 8 and 15. Id. Appellants argue that
the Examiner has not established that torque ripple is directly proportional to
current ripple. (App. Br. 9-10).
The Examiner's findings and conclusions regarding Kusase and
Nilson are located on pages 5---6 of the Final Action. The Examiner finds
that Kusase does not teach minimizing current ripple capable of being
generated due to the given leakage inductance as recited in claims 8 and 15
(Final Act. 5). The Examiner finds that Nilson teaches minimizing a current
ripple, citing to column 7, line 57. Id. The Examiner concludes that it would
have been obvious to make Kusase's induction motor to have a given
leakage inductance, "since it has been held to be within the general skill of a
worker in the art to select a known material on the basis of its suitability for
the intended use as a matter of obvious design choice." (Final Act. 6).
The column 7, line 57 disclosure of Nilson cited by the Examiner
teaches that "skewing the rotor is effective for reducing torque ripple and
cogging ripple." The Examiner relies on findings regarding a proportional
relationship of torque and current allegedly disclosed in Boules discussed
above with regard to rejection (1) to reason that the Nilson disclosure
regarding torque ripple relates to current ripple via the Boules
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proportionality (Ans. 4). As discussed above, Boules does not disclose the
exact proportional relationship (e.g., directly or inversely proportional) of
current and torque. The Examiner's findings are insufficient to establish that
Boules' unembellished disclosure of a proportional relationship between
torque and current means that torque ripple and current ripple are directly
proportional.
The Examiner has not dispensed with the burden of showing where all
the claim limitations are taught or suggested by Kusase and Nilson.
Rejections (3) and ( 4) of the dependent claims are faulty for the same
reasons discussed above. Therefore, on this record, we are constrained to
reverse the Examiner's§ 103(a) rejections (2) to (4).
DECISION
The Examiner's decision is reversed.
ORDER
REVERSED
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