Ex Parte Mathias et al

Board of Patent Appeals and Interferences

Jun 30, 2008

10643061 - (D) (B.P.A.I. Jun. 30, 2008)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
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Ex parte MARK F. MATHIAS,
JORG ROTH, and MICHAEL K. BUDINSKI,
Appellants
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Appeal 2008-3573
Application 10/643,0611
Technology Center 1700
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Decided: June 30, 2008
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Before CAROL A. SPIEGEL, LINDA M. GAUDETTE, and
MARK NAGUMO, Administrative Patent Judges.

NAGUMO, Administrative Patent Judge.

DECISION ON APPEAL

1 Application filed 18 August 2003, titled Diffusion Media for Use in a PEM
Fuel Cell. The real party in interest is listed as GM Corp. (Appeal Brief
filed 23 July 2007 ("Br."), at 1.)

Appeal 2008-3573
Application 10/643,061

Mark F. Mathias, Jorg Roth, and Michael K. Budinski (“Mathias”)
appeal from the final rejection of claims 1-102 under 35 U.S.C. § 102(b) in
view of Denton.3, 4 We REVERSE.
The claimed subject matter relates to “proton-exchange membrane
(“PEM”) fuel cells having a permeable diffusion media that is rigid along a
transverse axis, flexible along a lateral axis, and that is of substantially
incompressible thickness. As a result of these mechanical properties, the
diffusion media is said to be rollable in the machine direction and to provide
desirable mechanical properties to the finished PEM fuel cells.
Claim 1, which is representative of the issues necessary to resolve this
appeal, reads:
Claim 1
A PEM fuel cell comprising:
an electrode plate having a flow field formed therein; and
a membrane-electrode assembly including
permeable diffusion media disposed adjacent said
electrode plate,
said permeable diffusion media being rigid along a
transverse axis, flexible along a lateral axis and
having a substantially incompressible thickness,
wherein said transverse axis crosses first channels
of said flow field,
said first channels defining a predominate flow
direction.

2 The remainder of the pending claims, claims 11-25, stand withdrawn from
consideration.
3 Jan Denton, et al., Gas Diffusion Electrodes, U.S. Patent 6,010,606,
4 January 2000 ("Denton").
4 Examiner’s Answer (“Ans.”) mailed 18 October 2007, at 3.
2
Appeal 2008-3573
Application 10/643,061

(Claims App., Br. at 10; paragraphing and indentation added.)
The Examiner finds that Denton describes a fuel cell meeting all the
limitations of claims 1-10. (Ans. 3.) In particular, the Examiner finds that
Denton “discloses dimensionally stable (rigid) and highly flexible gas
diffusion electrodes” at column 4, lines 33-34. (Id.)
Mathias argues that the Examiner errs because Denton describes
diffusion media that are flexible regardless of direction. (Br. 5.) Mathias
argues that the Examiner errs further in equating the term “rigid,” as it
appears in the claims, with the term “dimensionally stable,” used by Denton.
(Br. 7.) Rather, according to Mathias, Denton’s dimensional stability refers
to stretching resistance. (Id., citing various passages in Denton.) Mathias
does not challenge any other aspect of the Examiner’s findings of fact.
The Examiner’s position is without merit. According to Denton, “[a]
major problem with conventional gas diffusion electrodes based on the
carbon fibre paper substrates is the lack of flexibility due to the rigid
substrate that is typically used.” (Denton 2:50-52.) Moreover, conventional
gas diffusion electrodes based on woven cloth substrates are said to “lack
good dimensional stability, as the cloth can easily be stretched in the
directions of the major planar faces.” (Id. at 58-59.) In Denton’s words,
“[a] major advantage of the present invention is that a free-standing,
dimensionally stable and highly flexible gas diffusion electrode is obtained.”
(Id. at 4:32-34.)
The Examiner has directed our attention to Denton at column 3, lines
40-50 and column 4, lines 33-34 in support of the rejection. (Ans. 3, 8.)
3
Appeal 2008-3573
Application 10/643,061

While Denton does refer to the introduction of “anisotropic character”
by using longer fibers, “typically ≥ 50 mm,” Denton does not refer to
stiffness. In the context of Denton’s disclosure, particularly Denton’s
statement in the next column that a major advantage of the disclosed
invention is obtaining a “free-standing, dimensionally stable and highly
flexible gas diffusion electrode” it cannot be said that Denton describes a
permeable diffusion media that is rigid along any axis. Thus, the
Examiner’s equation of dimensional stability with stiffness and anisotropic
properties (Ans. 8-9) is not supported by Denton. Nor has the Examiner
directed our attention to any description or definition in the supporting
disclosure that supports such a sweeping construction of the claim
terminology.
According to the Examiner’s reasoning, “[t]hough the claimed
recitation requires that the lateral axis has to be flexible and the transverse
axis has to be rigid, there are no limitations that [the] lateral axis cannot also
be rigid and the transverse axis cannot also be flexible.” (Ans. 8) Thus, the
Examiner's position is apparently that Denton's medium can be flexed both
transversely and laterally without the size and shape of the medium
changing, i.e., it is dimensionally stable and therefore rigid. However, a
dimensionally stable body is not necessarily a "rigid" body as required
because a body that is “rigid along a transverse axis” would not also be
flexible along that axis.
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Appeal 2008-3573
Application 10/643,061

In view of the record and the foregoing considerations, it is
ORDERED that the rejection of claims 1-10 under 35 U.S.C. § 102(b)
in view of Denton is REVERSED.
REVERSED

qsg

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