Ex Parte Reiser

Board of Patent Appeals and Interferences

Jun 15, 2010

10765737 (B.P.A.I. Jun. 15, 2010)

UNITED STATES PATENT AND TRADEMARK OFFICE
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BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
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Ex parte CARL A. REISER
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Appeal 2009-012813
Application 10/765,737
Technology Center 1700
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Decided: June 16, 2010
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Before TERRY J. OWENS, PETER F. KRATZ, and MARK NAGUMO,
Administrative Patent Judges.

OWENS, Administrative Patent Judge.

DECISION ON APPEAL
STATEMENT OF THE CASE
The Appellant appeals under 35 U.S.C. § 134(a) from the Examiner’s
rejection of claims 1-5, which are all of the pending claims. We have
jurisdiction under 35 U.S.C. § 6(b).

Appeal 2009-012813
Application 10/765,737

The Invention
The Appellant claims a method and apparatus for reducing
performance degradation due to hydrogen starvation of a fuel cell power
plant. Claim 1 is illustrative:
1. A method of reducing performance degradation due to
hydrogen starvation of a fuel cell power plant providing electrical power to a
load, comprising:

providing fuel reactant gas to fuel reactant gas flow fields of the fuel
cell power plant;

purging to ambient, at least periodically, at least a small amount of
partially depleted fuel reactant gas exiting from said flow fields;

sensing the direction of flow of gas between said flow fields and
ambient; and

disconnecting the electrical load from the fuel cell stack in the event
that there is no flow of gas from said flow fields toward ambient.

The References
de Vaal 6,815,101 B1 Nov. 9, 2004
(filed Jul. 25, 2001)
Gast 2005/0161520 A1 Jul. 28, 2005
(PCT filed Feb. 24, 2003)
The Rejection
The claims stand rejected as follows: claims 1, 2, 4 and 5 under
35 U.S.C. § 102(e) over de Vaal; claims 1 and 4 under 35 U.S.C. § 103 over
de Vaal; and claim 3 under 35 U.S.C. § 103 over de Vaal in view of Gast.
OPINION
We reverse the rejections.

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Application 10/765,737

Issue
Has the Appellant indicated reversible error in the Examiner’s
determination that de Vaal discloses, or would have rendered prima facie
obvious, to one of ordinary skill in the art, disconnecting the electrical load
from a fuel cell stack when there is no flow of gas from fuel reactant gas
flow fields toward ambient?
Findings of Fact
De Vaal stops operation of a fuel cell system “in response to either a
low oxygen concentration or a high hydrogen concentration in the ambient
atmosphere” (col. 14, ll. 48-51).
Analysis
Rejection under 35 U.S.C. § 102(e)
The Examiner argues that “[b]y measuring the concentration, as
described in the reference, flow is clearly taught and established” (Ans. 13)
and that “[b]y measuring the hydrogen content, flow from the fuel cell is
sensed” (Ans. 15). The Examiner argues that de Vaal “discloses
disconnecting the electrical load from the fuel cell stack in response to a low
gas concentration in the ambient atmosphere (column 14, lines 48-51). The
phrase ‘low gas flow’ encompasses the claimed limitation ‘no gas flow’”
(Ans. 5).
The Appellant argues that measuring hydrogen concentration in the
ambient air is not measuring hydrogen flow as hydrogen flows into the
ambient air, and that de Vaal does not disclose disconnecting the electrical
load in the event that there is no flow (Br. 8; Reply Br. 5).
The Examiner apparently considers de Vaal’s measured low oxygen
concentration to indicate low gas flow, including zero gas flow, such that
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Appeal 2009-012813
Application 10/765,737

when de Vaal stops operation of the fuel cell system in response to a
sufficiently low oxygen concentration (col. 14, ll. 48-51), the operation is
being stopped in response to no gas flow. That argument is not well taken
because the Examiner has not established that the oxygen concentration is
related to the gas flow rate, as opposed to the oxygen concentration and the
gas flow rate being separate variables which can be changed independently
such that a stream having a low oxygen concentration can have a high gas
flow rate.1
Rejections under 35 U.S.C. § 103
The Examiner argues that it would have been
obvious to disconnect the electrical load from the fuel cell
when no gas flow is sensed so as not to damage the fuel cell
due to lack of necessary gases and/or damage the load by
continuing operation under conditions in which the fuel cell
is not providing an uninterruptible power supply for the load
(column 14, lines 48-51). Certainly, one skilled in the art
would understand from these teachings that if low gas flow
may damage the fuel cell load, then no gas flow would inflict
the same damage

(Ans. 11).
The Appellant argues that there is nothing in the record to suggest
disconnecting the electrical load when no gas flow is sensed (Br. 6).
The support relied upon by the Examiner for the argument that
de Vaal teaches that low gas flow may damage the fuel cell is de Vaal’s
column 14, lines 48-51 (Ans. 11). That portion of de Vaal, however,

1 de Vaal discloses that the venting of hydrogen preferably is limited to a
rate such as less than 1 liter/minute to prevent the ambient environment
monitoring and control systems from triggering a failure or a fault (col. 8,
ll. 33-38), but de Vaal does not disclose shutting down the system in
response to no hydrogen flow.
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Appeal 2009-012813
Application 10/765,737

discloses stopping fuel cell operation in response to either a low oxygen
concentration or a high hydrogen concentration in the ambient atmosphere.
It does not disclose shutting down the fuel cell system in response to low gas
flow. Thus, the Examiner has not provided a factual basis for the
Examiner’s conclusion that it would have been obvious to one of ordinary
skill in the art to shut down de Vaal’s fuel cell system in response to no gas
flow. See In re Warner, 379 F.2d 1011, 1017 (CCPA 1967) (“A rejection
based on section 103 clearly must rest on a factual basis, and these facts
must be interpreted without hindsight reconstruction of the invention from
the prior art”).
Conclusion of Law
The Appellant has indicated reversible error in the Examiner’s
determination that de Vaal discloses, or would have rendered prima facie
obvious, to one of ordinary skill in the art, disconnecting the electrical load
from a fuel cell stack when there is no flow of gas from fuel reactant gas
flow fields toward ambient.
DECISION/ORDER
The rejections of claims 1, 2, 4 and 5 under 35 U.S.C. § 102(e) over
de Vaal, claims 1 and 4 under 35 U.S.C. § 103 over de Vaal, and claim 3
under 35 U.S.C. § 103 over de Vaal in view of Gast are reversed.
It is ordered that the Examiner’s decision is reversed.
REVERSED

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