Ex parte Dolmovich

Board of Patent Appeals and Interferences

Feb 3, 2000

08351874 (B.P.A.I. Feb. 3, 2000)

The application was filed on December 8, 1994. It is a1
continuation of Application Serial No. 07/943,928, which was
filed on September 11, 1992 and is now abandoned.
THIS OPINION WAS NOT WRITTEN FOR PUBLICATION
The opinion in support of the decision being entered today (1) was not written
for publication in a law journal and (2) is not binding precedent of the Board.
Paper No. 30
UNITED STATES PATENT AND TRADEMARK OFFICE
____________
BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________
Ex parte BRUCE E. DOLMOVICH
____________
Appeal No. 1997-0281
Application No. 08/351,8741
____________
HEARD: January 13, 2000
____________
Before KRASS, BARRETT, and BARRY, Administrative Patent Judges.
BARRY, Administrative Patent Judge.
DECISION ON APPEAL
This is a decision on the appeal under 35 U.S.C. § 134
from the final rejection of claims 1, 5-8, and 9-14. We
reverse.
Appeal No. 1997-0281
Application No. 08/351,874
Appeal No. 1997-0281 Page 3
Application No. 08/351,874
BACKGROUND
The invention at issue is an ignition system that
provides high energy ignition sparks at consistent voltage
levels. Ignition systems for igniting fuel in turbine engines
have been used widely since the 1950s. Historically, a gas-
filled device containing a spark gap has functioned as a
switch in these ignition systems. Such devices, however,
deteriorated with time and repeated sparking events.
Recently, solid-state switches have been substituted for gas-
filled spark gap devices. Although such switches are more
reliable over time than gas-filled spark gap devices, the
solid-state switches require external control circuitry, which
increases the parts count needed to implement an ignition
system. The invention provides a solid-state switch for a gas
turbine ignition system that possesses the reliability of
recent solid-state switches and reduces the parts count needed
to start an ignition system.
Claim 13, which is representative for our purposes,
follows:
Appeal No. 1997-0281 Page 4
Application No. 08/351,874
13. A capacitive discharge ignition system
responsive to a power source for igniting fuel to
power a turbine engine, the system comprising: a
capacitive energy storage device; power conditioning
circuitry responsive to the power source for pumping
approximately two joules or more of energy into the
capacitive energy storage device; an igniter plug
for igniting the fuel; output circuitry for
delivering the energy from the energy storage device
to the plug; a passive network having only two
terminals which connect the network to the
capacitive energy storage device and the output
circuitry for completing a path discharging the
capacitive energy storage device into the igniter
plug; the passive network comprising (1) a solid-
state switch for alternately providing high and low
impedance paths between the two terminals, thereby
selectively discharging the capacitive energy
storage device into the output circuitry and the
igniter plug, and (2) a breakover diode responsive
to a predetermined value of a voltage differential
()V) between the two terminals for effecting the
switching of the path between the two terminals
provided by the solid-state switch from a high
impedance value to a low impedance value, thereby
controllably discharging the capacitive energy
storage device into a spark gap of the igniter plug
by way of the output circuitry.
Besides the appellant‘s admitted prior art (AAPA), the
references relied on in rejecting the claims follow:
Roberts 3,349,284 Oct. 24, 1967
Hirosawa et al. 3,367,314 Feb. 6, 1968
(Hirosawa)
Wolf et al. 4,449,497 May 22, 1984.
(Wolf)
Appeal No. 1997-0281 Page 5
Application No. 08/351,874
Claims 1, 4, and 14 stand rejected under 35 U.S.C. § 103
as obvious over AAPA in view of Hirosawa. Claims 5 and 10
stand rejected under § 103 as obvious over AAPA in view of
Hirosawa further in view of Roberts. Claims 6-8 stand
rejected under § 103 as obvious over AAPA in view of Hirosawa
further in view of Wolf. Claims 11-13 stand rejected under
§ 103 as obvious over Hirosawa. Rather than repeat the
arguments of the appellant or examiner in toto, we refer the
reader to the brief and answer for the respective details
thereof.
OPINION
In reaching our decision in this appeal, we considered
the subject matter on appeal and the rejections advanced by
the examiner. Furthermore, we duly considered the arguments
and evidence of the appellant and examiner. After considering
the totality of the record, we are persuaded that the examiner
erred in rejecting claims 1, 5-8, and 9-14. Accordingly, we
reverse.
Appeal No. 1997-0281 Page 6
Application No. 08/351,874
We begin by noting the following principles from In re
Rijckaert, 9 F.3d 1531, 1532, 28 USPQ2d 1955, 1956 (Fed. Cir.
1993).
In rejecting claims under 35 U.S.C. Section 103,
the examiner bears the initial burden of presenting
a prima facie case of obviousness. In re Oetiker,
977 F.2d 1443, 1445, 24 USPQ2d 1443, 1444 (Fed. Cir.
1992). Only if that burden is met, does the burden
of coming forward with evidence or argument shift
to the applicant. Id. "A prima facie case of
obviousness is established when the teachings from
the prior art itself would appear to have suggested
the claimed subject matter to a person of ordinary
skill in the art." In re Bell, 991 F.2d 781, 782,
26 USPQ2d 1529, 1531 (Fed. Cir. 1993) (quoting In re
Rinehart, 531 F.2d 1048, 1051, 189 USPQ 143, 147
(CCPA 1976)). If the examiner fails to establish a
prima facie case, the rejection is improper and will
be overturned. In re Fine, 837 F.2d 1071, 1074, 5
USPQ2d 1596, 1598 (Fed. Cir. 1988).
With these in mind, we analyze the appellant’s argument.
The appellant argues, “Breakover diodes and Zener diodes
are distinct devices with completely different architectures
and operating different architectures and operating
characteristics. As such, breakover diodes and Zener diodes
cannot be used interchangeably and are, in fact, suited for
completely different applications." (Dolmovich Decl., ¶ 3.)
He adds, “the rejections ... are improperly based on a
Appeal No. 1997-0281 Page 7
Application No. 08/351,874
hindsight reconstruction of the invention; ... no suggestion
for making the combination recited in the Office action
appears in the art of record ....” (Appeal Br. at 17.) The
examiner replies, “the fact is that they are art recognized
equivalent which is not the same as pure functional
equivalence as Mr. Dolmovich argues.” (Examiner’s Answer at
10.) He adds, “the selection of any of these known
equivalents to provide a conductive voltage dependent
condition i.e. breakdown, breakover, etc. would be within the
level of ordinary skill in the art.” (Id. at 5.) We agree
with the appellant.
Claims 1, 5-8, 10, and 14 each specifies in pertinent
part the following limitations:
a breakover diode connected in a forwardly biased
manner between the input of the first SCR and the
trigger input of the first SCR, the at least one
breakover diode being responsive to a predetermined
value of a voltage differential ()V) between the two
terminals of the passive network for switching the
first SCR from the high impedance path to the low
impedance path to controllably discharge the
capacitive energy storage device to the igniter
plug.
Appeal No. 1997-0281 Page 8
Application No. 08/351,874
Similarly, claim 11 specifies in pertinent part the following
limitations:
a breakover diode responsive to the voltage
differential ()V) between the input and output
terminals for switching the path between the two
terminals provided by the solid-state switch from a
high impedance value to a low impedance value,
thereby controllably discharging the energy from the
capacitive energy storage device to the igniter plug
by way of the output circuitry.
Also similarly, claim 12 specifies in pertinent part the
following limitations:
a breakover diode (BOD) responsive to the voltage
differential ()V) between the input and output
terminals for effecting the switching of the path
between the two terminals provided by the solid-
state switch from a high impedance value to a low
impedance value, thereby controllably discharging
the energy stored in the capacitive energy storage
device to the igniter plug by way of the output
circuitry, where the BOD includes an anode connected
to the input terminal and a cathode connected to a
trigger input of the solid-state switch.
Also similarly, claim 13 specifies in pertinent part the
following limitations:
a breakover diode responsive to a predetermined
value of a voltage differential ()V) between the two
terminals for effecting the switching of the path
between the two terminals provided by the solid-
state switch from a high impedance value to a low
impedance value, thereby controllably discharging
Appeal No. 1997-0281 Page 9
Application No. 08/351,874
the capacitive energy storage device into a spark
gap of the igniter plug by way of the output
circuitry.
In summary, the limitations recite employing a breakover diode
responsive to a predetermined voltage differential between two
terminals of a passive network to switch a path between the
terminals from a high impedance value to a low impedance value
to controllably discharge a capacitor into an igniter plug.
The examiner fails to show a teaching or suggestion of
these limitations in the prior art. The examiner admits,
“AAPA and Horosawa [sic] also lacks [sic] the use of a break-
over diode for the triggering means of the SCR.” (Examiner’s
Answer at 6.) He further admits, “the Zener and the break-
over diode are not identical, i.e. functional equivalent
[sic].” (Id. at 10.) Nonetheless, the examiner alleges that
the two elements “are art recognized equivalent [sic].” (Id.)
He offers U.S. Patent No. 3,061,755 (Spira) as evidence of the
art recognized equivalence. Specifically, the examiner notes,
“Spira clearly shows the use of BOD [i.e., a breakover diode]
in the same or the similar circuit where a Zener is used.”
(Id. at 11.)
Appeal No. 1997-0281 Page 10
Application No. 08/351,874
Spira teaches a “combination of a switching means, a
rectifier means, and a controllably conductive means which can
control the flow of electrical current therethrough in a
selective manner.” Col. 2, ll. 19-23. The combination is
used “in a system for selectively diming [sic] the lumen
output of an electric lamp.” Col. 1, ll. 16-17. The
reference specifically teaches employing a four-layer type
diode, i.e., a breakover diode, as the controllably conductive
element of the combination. Col. 6, ll. 38-42. Spira also
specifically discloses, “the controllable conductive element
could be the type device known as the Zener diode.” Id. at
ll. 42-44.
At best, the reference evidences that breakover diodes
and Zener diodes were recognized as equivalents in the art of
lamp dimming. The appellant’s invention, however, “relates to
ignition system ....” (Spec. at 1.) Spira does not evidence
that breakover diodes and Zener diodes were recognized as
equivalents in the art of ignition systems. In fact, the
examiner has not offered any evidence of the equivalence of
Appeal No. 1997-0281 Page 11
Application No. 08/351,874
the elements in the art of ignition systems. Neither Roberts
nor Wolf remedies this deficiency.
For the foregoing reasons, we are not persuaded that the
prior art would have suggested employing a breakover diode
responsive to a predetermined voltage differential between two
terminals of a passive network to switch a path between the
terminals from a high impedance value to a low impedance value
to controllably discharge a capacitor into an igniter plug.
The examiner has not established a prima facie case of
obviousness. Therefore, we reverse the rejection of claims 1,
5-8, and 9-14 under 35 U.S.C. § 103.
Appeal No. 1997-0281 Page 12
Application No. 08/351,874
CONCLUSION
To summarize, the examiner’s rejection of claims 1, 5-8,
and 9-14 under 35 U.S.C. § 103 is reversed.

REVERSED
ERROL A. KRASS )
Administrative Patent Judge )
)
)
)
) BOARD OF PATENT
LEE E. BARRETT ) APPEALS
Administrative Patent Judge ) AND
) INTERFERENCES
)
)
)
LANCE LEONARD BARRY )
Administrative Patent Judge )
Appeal No. 1997-0281 Page 13
Application No. 08/351,874
LLB/kis
Appeal No. 1997-0281 Page 14
Application No. 08/351,874
JAMES A. FLIGHT
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