Ex Parte Bunker et al

Board of Patent Appeals and Interferences

Sep 8, 2010

10907773 (B.P.A.I. Sep. 8, 2010)

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.
10/907,773 04/14/2005 Thomas A. Bunker 13653 (ITWO:0331) 4773
52145 7590 09/09/2010
FLETCHER YODER (ILLINOIS TOOL WORKS INC.)
P.O. BOX 692289
HOUSTON, TX 77269-2289
EXAMINER
RALIS, STEPHEN J
ART UNIT PAPER NUMBER
3742
MAIL DATE DELIVERY MODE
09/09/2010 PAPER
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.
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________

Ex parte THOMAS A. BUNKER, JOSEPH C. SCHNEIDER
and JAMES F. ULRICH
____________

Appeal 2008-006372
Application 10/907,773
Technology Center 3700
____________

Before JENNIFER D. BAHR, JOHN C. KERINS, and STEVEN D.A.
McCARTHY, Administrative Patent Judges.

KERINS, Administrative Patent Judge.
DECISION ON APPEAL1

1 The two-month time period for filing an appeal or commencing a civil
action, as recited in 37 C.F.R. § 1.304, or for filing a request for rehearing,
as recited in 37 C.F.R. § 41.52, begins to run from the “MAIL DATE”
(paper delivery mode) or the “NOTIFICATION DATE” (electronic delivery
mode) shown on the PTOL-90A cover letter attached to this decision.
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STATEMENT OF THE CASE
Thomas A. Bunker et al. (Appellants) seek our review under 35
U.S.C. § 134 of the Examiner’s rejection of claims 1-10 and 17-22. Claims
11-16 were previously canceled and claims 23-26 have been withdrawn
from consideration. We have jurisdiction under 35 U.S.C. § 6(b) (2002).
We AFFIRM-IN-PART.
THE INVENTION
Appellants’ claimed invention is to a plasma cutter or plasma cutting
system that converts DC welding power to plasma cutting power. Claims 1,
5, 6 and 9 are reproduced below, and are illustrative of the claimed subject
matter at issue on appeal:
1. A plasma cutter comprising:

an input configured to receive DC welding power
from a welder; and

a converter arranged according to a Cuk topology
and configured to automatically convert the DC
welding power to plasma-cutting power.

5. The plasma cutter of claim 1 further comprising
an active feedback loop configured to monitor and
control voltage of the plasma-cutting power to
remain below a desired limit.

6. The plasma cutter of claim 1 further comprising
an active feedback loop configured to monitor and
control current of the DC welding power to
maintain a thermal output of the converter below a
desired limit.

9. The plasma cutter of claim 1 wherein the input
is configured to receive an end of a welding torch
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connected to the welder to receive DC welding
power from the welder.

THE REJECTIONS
The Examiner has rejected:
(i) claims 1, 2, 7, 9 and 10 under 35 U.S.C. § 103(a) as being
unpatentable over Thommes (US 5,086,205, issued February 4, 1992), in
view of Ulrich (US 6,236,014 B1, issued May 22, 2001) and a publication of
TESLAco titled “About Technology”, appearing at
http://www.teslaco.com/inverter.htm at least as early as December 1, 1998
(hereafter “TESLAco”);
(ii) claim 3 under 35 U.S.C. § 103(a) as being unpatentable over
Thommes in view of Ulrich, TESLAco and Church (US 6,177,645 B1,
issued January 23, 2001);
(iii) claim 4 under 35 U.S.C. § 103(a) as being unpatentable over
Thommes in view of Ulrich, TESLAco and Ikeda (US 6,181,576 B1, issued
January 30, 2001);
(iv) claims 5, 6 and 8 under 35 U.S.C. § 103(a) as being unpatentable
over Thommes in view of Ulrich, TESLAco and Borowy (US 6,365,868 B1,
issued April 2, 2002);
(v) claim 18 under 35 U.S.C. § 103(a) as being unpatentable over
Thommes in view of Crandell (US 2003/0164645 A1, published September
4, 2003), Ulrich and TESLAco;
(vi) claims 19 and 20 under 35 U.S.C. § 103(a) as being unpatentable
over Thommes in view of Crandell, Ulrich, TESLAco and Borowy;
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(vii) claims 17 and 21 under 35 U.S.C. § 103(a) as being unpatentable
over Thommes in view of Crandell, Ulrich, TESLAco, Borowy and Ikeda;
and
(viii) claim 22 under 35 U.S.C. § 103(a) as being unpatentable over
Thommes in view of Crandell, Ulrich, TESLAco and Hoyt (US 4,465,920,
issued August 14, 1984).
ISSUES
Is the combination of the teachings of the Ulrich and TESLAco
references with the teachings of the Thommes patent in error?
Does the combination of the teachings of Thommes, Ulrich and
TESLAco render obvious a plasma cutter in which the input is configured to
receive an end of a welding torch to receive DC welding power from a
welder?
Does the combination of the teachings of Thommes, Ulrich,
TESLAco and Borowy render obvious a plasma cutter having an active
feedback loop configured to (a) monitor and control voltage of a plasma-
cutting power to remain below a desired limit; or (b) monitor and control
current of the DC welding power to maintain a thermal output of the
converter below a desired limit?
ANALYSIS
Claims 1, 2, 7, 9 and 10--Thommes/Ulrich/TESLAco
Appellants present arguments for patentability directed to independent
claim 1 and dependent claim 9. No arguments for the patentability of claims
2, 7 and 10, which depend from claim 1, separate and apart from those
presented for claim 1, have been made. Claim 1 will be taken as
representative of the group including claims 1, 2, 7 and 10. 37 CFR
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§ 41.37(c)(1)(vii)(2009).
The Examiner found that the Thommes patent discloses all elements
set forth in claim 1, with the exception that the boost circuit which
automatically converts a DC welding power received from a welder to a
plasma-cutting power is not arranged as a Cuk converter, or according to a
Cuk topology, as required by claim 1. (Ans. 4-5). The Examiner further
found that the Ulrich patent discloses an apparatus for supplying
welding/plasma power for welding and plasma cutting, in which a boost
circuit employing a Cuk converter provides a voltage magnitude across a DC
bus signal that is at least 10 percent greater than the input signal. (Ans. 5;
see also, Ulrich, Abstract, and col. 7, ll. 46-51). The Examiner further cites
to the TESLAco publication as evidencing that a Cuk converter is
recognized as having a high efficiency relative to other converters that use
identical components. (Ans. 5). Relying on these findings, the Examiner
concludes that it would have been obvious to modify the Thommes
converter, substituting a boost circuit of a Cuk configuration, as taught by
Ulrich, for the boost circuit disclosed by Thommes, in order to provide a
circuit with an increased voltage magnitude that is at least 10 percent greater
than the input signal, and having higher efficiency. (Ans. 5-6).
Appellants’ principal contention is that, since Ulrich discloses a
welding/plasma power source that may include a Cuk converter and other
components for converting welding power to plasma-cutting power, and
since Thommes already teaches a converter for converting welding power to
plasma-cutting power, there is no motivation for a person skilled in the art to
modify Thommes as proposed by the Examiner to arrive at the claimed
invention. (Appeal Br. 4-5). Examiners are no longer required to find and
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express a specific teaching, suggestion, or motivation for making a proposed
combination, and instead are charged with presenting an apparent reason to
combine teachings, as by, for example, articulating some reasoning
supported by rational underpinnings. KSR Int'l Co. v. Teleflex Inc., 550 U.S.
398, 418 (2007). Notwithstanding, in the present situation, the Examiner’s
stated reason to combine the teachings of Ulrich and TESLAco with
Thommes, to produce an increased voltage output and higher efficiency,
appears to constitute a motivation to combine.
At a minimum, the Examiner’s reasoning is supported by rational
underpinnings. Appellants do not challenge the Examiner’s findings,
recounted supra., as being incorrect or inaccurate, and do not contend that
the modification to Thommes would not provide the benefits identified by
the Examiner. (Appeal Br., passim; Reply Br., passim). Appellants further
do not challenge the Examiner’s averment (see, Ans. 19) that incorporating
the Cuk converter of Ulrich into or in place of the converters disclosed in
Figures 3-6 of Thommes would provide an expectation of success. From
this, the Examiner further concluded (id.), that the proposed modification
and the invention of claim 1 would have been obvious to one of ordinary
skill in the art, on the basis that it amounts to a substitution of one known
element for another, yielding the predictable result of an increase in power
output. KSR Int’l., 550 U.S. at 417. Appellants have not directly addressed
this conclusion, and have not otherwise persuaded us that the conclusions
reached by the Examiner are in error.
The rejection of claim 1, and of claims 2, 7 and 10 depending
therefrom, will be sustained.
Appellants contend, with respect to claim 9, that:
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[r]egardless of the Examiner’s interpretation of
“DC welding supply” and that the welding power
supply may be engine-driven and may be adapted
for powering a cutting torch, Thommes fails to
teach or suggest that the input is configured to
receive an end of a welding torch connected to a
welder to receive DC welding power from the
welder.
(Appeal Br. 5-6).
We agree. The subject matter of claim 9, which requires the input of
the plasma cutter to be configured to receive an end of a welding torch,
admits of a structural limitation, and not, as maintained by the Examiner, a
functional one. (Ans. 21). The Examiner has not identified any portion of
the Thommes disclosure, and we are likewise unable to find any such
portion, that discloses or suggests that the converter in Thommes includes an
input that is physically configured to receive the end of a welding torch. The
Ulrich and TESLAco references are of no avail in this regard, either.
The rejection of claim 9 will not be sustained.
Claim 3--Thommes/Ulrich/TESLAco/Church
Appellants present no additional arguments controverting the rejection
of claim 3, which depends from claim 1. The arguments presented for claim
1 were found to be unpersuasive, as noted above. We will therefore sustain
the rejection of claim 3 as well.
Claim 4--Thommes/Ulrich/TESLAco/Ikeda
Appellants present no additional arguments controverting the rejection
of claim 4, which depends from claim 1. The arguments presented for claim
1 were found to be unpersuasive, as noted above. We will therefore sustain
the rejection of claim 4 as well.

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Claims 5, 6 and 8--Thommes/Ulrich/TESLAco/Borowy
Claims 5 and 6 each depend from claim 1. Claim 5 calls for the
plasma cutter to have an active feedback loop configured to monitor and
control voltage of the plasma-cutting power to remain below a desired limit.
(Claim 5, reproduced supra.). Claim 6 calls for the plasma cutter to have an
active feedback loop configured to monitor and control current of the DC
welding power to maintain a thermal output of the converter below a desired
limit. (Claim 6, reproduced supra.). Claim 8 depends from claims 1 and 7,
and calls for the plasma cutter to have an active feedback loop configured to
monitor and control voltage received from the welder to maintain an engine
speed of the engine-driven generator.
Appellants do not present any arguments directed to the rejection of
claim 8 and the limitations contained therein. Because we have decided to
affirm the rejection of claims 1 and 7, from which claim 8 depends, and
because Appellants have failed to separately contest the rejection of claim 8,
the rejection will be sustained.
Turning to claims 5 and 6, the Examiner relies on Borowy in addition
to the references relied on in rejecting claim 1 in reaching a conclusion that
the subject matter of claims 5 and 6 would have been obvious. Appellants
do not take issue with the propriety of employing Borowy in combination
with Thommes, Ulrich and TESLAco. Rather Appellants contend that
Borowy has been misinterpreted by the Examiner, such that, even if
combined, the combination would not render obvious the invention of claims
5 and 6. (Appeal Br. 6-7).
Appellants contend that Borowy fails to teach or suggest controlling
voltage of the plasma-cutting power to remain below a desired limit, in that
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the power factor boost stage relied on by the Examiner as teaching the
limitations in claim 5 provides a power output to an inverter stage, and thus
does not control the voltage of the plasma-cutting power. (Appeal Br. 6).
Borowy discloses that the inverter stage receives the power output from the
power factor boost stage, and that voltage divider resistors 190, 190' ensure
that the voltage of the output of the boost stage is divided in half. (Borowy,
col. 8, ll. 18-27). The divided voltage signals are processed by a transformer
to generate an output suitable for cutting. (Borowy, col. 8, ll. 29-34). The
control of the voltage being output from the power factor boost stage thus
appears to ultimately control the voltage of the plasma cutting power. The
additional language in claim 5 requiring the voltage to be controlled to
“remain below a desired limit” does not, without some specific constraint on
the term “desired limit”, aid in patentably distinguishing the claim over the
combination of references.
We are thus unpersuaded that the combination of the teachings of
Borowy with those of Thommes, Ulrich and TESLAco, fails to render
obvious the subject matter of claim 5.
Appellants contend, with respect to claim 6, that Borowy does not
disclose monitoring and control of current of the DC welding power to
maintain a thermal output of the converter below a desired limit. (Appeal
Br. 7). More specifically, Appellants argue that the current sensor 175 of
Borowy, relied on by the Examiner as a component that allows the active
feedback loop controlled by DSP 50 to monitor current, is used as an input
to a switch controller 170, which in turn functions to “adjust the duty cycle
[of the switch] to perform the power factor correction.” (Borowy, col. 7, ll.
39-43).
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The power factor correction, as correctly maintained by Appellants, as
well as the adjustment of the duty cycle of the switch, pertain to control of
the output, and particularly the voltage, of the power factor corrected boost
stage 35, 35'. (Borowy, Figs. 4A, 4B; col. 7, ll. 16-25). In contrast, claim 6
calls for monitoring and control of the current of the DC welding power,
which is the input to the converter as seen from claim 1. Notwithstanding
the citation to a passage appearing at column 1, lines 40-52 of Borowy
indicating a desirability to provide a generally flat and regulated DC bus, the
Examiner has not satisfactorily established how the current sensor 175 and
active feedback loop/DSP 50 operate to control the input current of the
Borowy device.
We also will not stand behind the Examiner’s use of the widely
known relationship among power, current and voltage (P = I * E) in
concluding that it would have been obvious to a person of ordinary skill in
the art to control current instead of controlling voltage in a power delivery
apparatus. (Ans. 10, 22). We agree with Appellants, that it is not generally
obvious to control current instead of controlling voltage in all circumstances.
(Reply Br. 2). Absent specific findings relating to the circuits and systems
in the references relied on in making the rejection of claim 6, and detailing
why persons of ordinary skill would find it obvious to control current instead
of voltage in the combination of teachings, we cannot sustain the rejection.
The rejection of claim 5 will be sustained. The rejection of claim 6
will not be sustained.
Claim 18--Thommes/Crandell/Ulrich/TESLAco
Independent claim 18 differs somewhat in scope from claim 1,
addressed above. However, Appellants’ contentions with respect to the
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rejection of claim 18 are essentially identical to those expressed with respect
to the rejection of claim 1, and are directed to an asserted lack of motivation
to combine the teachings of the Thommes and Ulrich patents. Accordingly,
our analysis and decision directed to claim 1 above apply equally here.
The rejection of claim 18 will be sustained.
Claims 19 and 20--Thommes/Crandell/Ulrich/TESLAco/Borowy
Appellants present no additional arguments controverting the rejection
of claims 19 and 20, which depend directly or indirectly from claim 18. The
arguments presented for claim 18 were found to be unpersuasive, as noted
above. We will therefore sustain the rejection of claims 19 and 20 as well.
Claims 17 and 21--Thommes/Crandell/Ulrich/TESLAco/Borowy/Ikeda
Appellants present no additional arguments controverting the rejection
of claim 21, which depends from claim 18, nor the rejection of claim 17,
which depends from claim 21. The arguments presented for claim 18 were
found to be unpersuasive, as noted above. We will therefore sustain the
rejection of claims 17 and 21 as well.
Claim 22--Thommes/Crandell/Ulrich/TESLAco/Hoyt
Appellants present no additional arguments controverting the rejection
of claim 22, which depends from claim 18. The arguments presented for
claim 18 were found to be unpersuasive, as noted above. We will therefore
sustain the rejection of claim 22 as well.

CONCLUSIONS
We are not persuaded that the combination of the teachings of the
Ulrich and TESLAco references with the teachings of the Thommes patent is
in error.
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We are persuaded that the combination of teachings of Thommes,
Ulrich and TESLAco does not render obvious a plasma cutter in which the
input is configured to receive an end of a welding torch to receive DC
welding power from a welder.
We are not persuaded that the combination of the teachings of
Thommes, Ulrich, TESLAco and Borowy fails to render obvious a plasma
cutter having an active feedback loop configured to monitor and control
voltage of a plasma-cutting power to remain below a desired limit.
We are persuaded that the Examiner has not established that the
combination of the teachings of Thommes, Ulrich, TESLAco and Borowy
renders obvious a plasma cutter having an active feedback loop configured
to monitor and control current of the DC welding power to maintain a
thermal output of the converter below a desired limit.
DECISION
The decision of the Examiner to reject claims 1-5, 7, 8, 10, and 17-22
is AFFIRMED. The decision of the Examiner to reject claims 6 and 9 is
REVERSED.
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) (2007).

AFFIRMED-IN-PART

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mls

FLETCHER YODER (ILLINOIS TOOL WORKS INC.)
P.O. BOX 692289
HOUSTON TX, 77269-2289