Ex Parte Gilman et al

Board of Patent Appeals and Interferences

May 8, 2008

10341617 (B.P.A.I. May. 8, 2008)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________

Ex parte JOHN GILMAN and DANIEL A. KEARL
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Appeal 2008-0743
Application 10/341,617
Technology Center 1700
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Decided: May 8, 2008
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Before CATHERINE Q. TIMM, JEFFREY T. SMITH, and
MICHAEL P. COLAIANNI, Administrative Patent Judges.

TIMM, Administrative Patent Judge.

DECISION ON APPEAL
Appellants appeal under 35 U.S.C. § 134(a) from the Examiner’s
decision rejecting claims 38-42 and 59-66. We have jurisdiction under 35
U.S.C. § 6(b).
We REVERSE.

Appeal 2008-0743
Application 10/341,617

I. BACKGROUND
The invention relates to a fuel cell system comprising utilizing
aerogels as sealing materials for fuel cell systems operating at temperatures
as high as 400ºC to 1000ºC. Claims 38 and 66 are illustrative of the subject
matter on appeal:
38. A fuel cell system comprising:
a high temperature fuel cell contained in a housing;
a fuel intake for providing fuel to said fuel cell;
an oxygen intake for providing oxygen to said fuel cell;
an exhaust path for exhaust from said fuel cell; and
a first aerogel seal disposed between said fuel cell and said
housing.

66. A fuel cell system comprising:
a high temperature fuel cell contained in a housing;
a fuel intake extending through said housing for providing
fuel to said fuel cell;
an oxygen intake extending through said housing for providing
oxygen to said fuel cell;
an exhaust path extending through said housing for exhausting
exhaust from said fuel cell; and
a seal comprising aerogel disposed between components of said
system within said housing.

The Examiner relies on the following prior art references to show
unpatentability:
Grevstad et al. US 4,212,929 Jul. 15, 1980
McPheeters et al. US 4,761,349 Aug. 2, 1988
Cubukcu et al. US 6,074,771 Jun. 13, 2000
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The Examiner maintains the following rejections:
1. Claims 38-42 and 59-66 rejected under 35 U.S.C. § 103(a) as
obvious over Grevstad et al. (“Grevstad”) in view of Cubukcu et al.
(“Cubukcu”); and
2. Claims 38-42 and 59-66 rejected under 35 U.S.C. § 103(a) as
obvious over McPheeters et al. (“McPheeters”) in view of Cubukcu.
II. DISCUSSION
The Examiner finds that “Cubukcu illustrates using the aerogel
material to serve as a seal” namely due to its “low thermal conductivity and
light-weight.” (Ans. 7). According to the Examiner, “[i]t would be obvious
to one of ordinary skill in the art at the time of the invention to extrapolate
this teaching to using an aerogel seal for any area that would benefit from
any of the inherent characteristics of aerogel.” (Ans. 7).
Appellants respond that the Examiner overstates the teachings of
Cubukcu and that “Cubucku teachings [sic, teaches] using aerogel primarily
as an exterior insulation that may also perform something of a sealing
function on the exterior of a fuel cell.” (Reply Br. 5). Appellants also argue
that “the interior of a fuel cell system is a particularly demanding
environment” and that “there is no teaching of record in any of the cited
prior art references of using aerogel as a material for a seal within a fuel cell
system. (Reply Br. 5)(emphasis in original).
The issue on appeal arising from the contentions of Appellants and the
Examiner is: Did the Examiner reversibly err in extrapolating the teachings
of Cubukcu to find that one of ordinary skill in the art would have known to
use an aerogel as a suitable material for the gasket seals taught by Grevstad
or McPheeters? We answer this question in the affirmative.
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Application 10/341,617

We make the following Findings of Fact (FF):
1. The Summary of the Specification teaches that “a high
temperature seal including an aerogel gasket is disposed between two or
more components of a high temperature fuel cell system.” (Spec. ¶ [0008]).
The Specification describes that “gaskets made from an aerogel can provide
the desired seal between fuel cell systems components.” (Spec. ¶ [0027]).
The Specification also uses the terms “seals” or “gaskets” interchangeably
throughout the Specification. (Spec. ¶ [0024], [0025], [0030], [0032]).
Further, in each of the examples in the Specification, the seals are described
as “gaskets,” particularly an “annular seal or gasket,” a “flange gasket” and a
“perimeter gasket.” (Spec. ¶¶ [0033]-[0036]).
2. The Specification also describes “many interfaces between
system components, one or more of which may use seals or gaskets to
prevent leakage.” (Spec. ¶ [0024]). The Specification identifies some of
these interfaces as being located between the housing (104) and one of the
following: the fuel cell (102), the fuel supply (106), the oxygen supply
(108), the exhaust paths (110/112) and the electrical interconnections
(114/116). (Spec. ¶ [0024]; Fig. 1).
3. The Specification also describes that
[e]ach of the aerogel gaskets or seals described
above may be made by stamping or cutting an
aerogel sheet into any desired configuration.
According to one embodiment, an aerogel sheet is
cut to form gaskets by a water jet. However, any
other forming, casting, stamping, or cutting
method may also be used. Several examples of the
configurations that may be useful for high
temperature fuel cell system seals are discussed
below with reference to the figures.
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Application 10/341,617

(Spec. ¶ [0032]).
4. The Specification describes that, because aerogels are otherwise
typically porous, it is desirable to pulverize and reconstitute aerogels to
reduce or eliminate permeability for high temperature sealing applications.
(Spec. ¶ [0029]).
5. Grevstad teaches “securing a polymer seal frame between the
manifold and the stack such that as the stack creeps, the seal frame creeps
with it.” (Grevstad, col. 3, ll. 14-16; Fig. 1). In particular, Grevstad
describes “a polymer seal frame 15’ is located between a lip or edge 17 of a
manifold 18… and the cell stack 10’.” (Grevstad, col. 3, ll. 36-39).
6. McPheeters teaches that:
[a]s shown in FIG. 3, first and second seals 78 and
82 extend substantially along the entire length of
the facing, lateral edges of the solid oxide fuel cell
20 to ensure that the oxidant and fuel gases remain
confined within the respective flow channels
therein. A third seal 80 is disposed generally
transverse to the plane of the solid oxide fuel cell
20 and provides for separation between the inlet
and outlet flow paths of the oxidant and fuel gases.
Each of the first, second and third seals 78, 82 and
80 is disposed in tightfitting relation between the
monolithic core 64 of the solid oxide fuel cell 20
and its outer insulating housing or sheath 40.
(McPheeters, col. 10, l. 62- col. 11, l. 5; Figs. 2-3).
7. Cubukcu teaches that “[t]o ensure sealing surrounding the
incoming air and exhaust openings, Aerogel or Microtherm insulation
having a very low thermal conductivity, such as 0.02 W/MK at 400ºC., and
very low weight, is also preferably provided surrounding the shell 24.”
(Cubukcu, col. 20, ll. 5-9).
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8. Cubukcu teaches a fuel cell made from foil layers sealed
together to form a fluid fuel input 21 and a gas output passageway 22
extending out of an arm 12b, where a “foil patch 51 seals the incoming fuel
from escaping or mixing with the outgoing exhaust fuel.” (Cubukcu, col. 6,
ll. 12-66; Figs. 13A-C and 16). Cubukcu also teaches using silicone rubber
to form and to seal around an inlet/exhaust gas manifold 130, “to prevent the
release of exhaust gas from the manifold other than through an outlet 136
provided in the manifold shell 132.” (Cubukcu, col. 18, ll. 9-44; Figs. 26D-
26G).
9. Cubukcu also teaches using a layer of Interam™ sealing material
168 “between the incoming duct 146 and an exhaust cap 170” and between
“incoming cap openings 154 and the gas bypass openings 145,” which
expands when heated and forms “a nominally gas tight seal to prevent
leakage.” (Cubukcu, col. 19, ll. 59-64, col. 20, ll. 10-15, Figs. 26B and
26C).
A claimed invention is unpatentable if the differences between it and
the prior art are such that the subject matter as a whole would have been
obvious at the time the invention was made to a person having ordinary skill
in the pertinent art. 35 U.S.C. § 103(a)(2000); Graham v. John Deere Co. of
Kansas City, 383 U.S. 1, 13-14 (1966). Factors to consider in determining
obviousness include “‘the scope and content of the prior art,’” “‘the
differences between the prior art and the claims at issue,’” and “‘the level of
ordinary skill in the pertinent art.’” Dann v. Johnston, 425 U.S. 219, 226
(1976) (quoting Graham, 383 U.S. at 17).
However, “rejections on obviousness grounds cannot be sustained by
mere conclusory statements; instead, there must be some articulated
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reasoning with some rational underpinning to support the legal conclusion of
obviousness.” In re Kahn, 441 F.3d 977, 988 (Fed. Cir. 2006) (quoted with
approval in KSR Int'l Co. v. Teleflex Inc., 127 S. Ct. 1727, 1741 (2007)).
The Examiner bears the initial burden, on review of prior art or on any
other ground, of presenting a prima facie case of non-patentability. In re
Oetiker, 977 F.2d 1443, 1445 (Fed. Cir. 1992). Here, the Examiner has not
established a prima facie case of obviousness with respect to the only
independent claims, claims 38 and 66. In particular, we determine that the
Examiner has not adequately demonstrated that the teaching of Cubukcu
would have suggested to one of ordinary skill in the art the use of an aerogel
as a suitable material in seals such as those taught by Grevstad and
McPheeters.
Reading the claims in light of the Specification, we determine that
Appellants are using the term “aerogel seal” to mean an “aerogel gasket.”
Evidence on which we base our determination includes: the Summary of the
Invention which designates the “high temperature seal” an “aerogel gasket”;
the use of “seal or gasket” elsewhere in the Specification; and the examples
which all describe gaskets (FF 1). Also, the “seal” is located at the interface
between system components (FF 2), traditionally the location of gaskets, and
is stamped or cut from a sheet (FF 3), which is the type of manufacture used
to form gaskets. See Phillips v. AWH Corp., 415 F.3d 1303, 1315 (Fed. Cir.
2005) (“claims ‘must be read in view of the specification, of which they are
a part.’[citation omitted] [T]he specification ‘is always highly relevant to the
claim construction analysis. Usually, it is dispositive; it is the single best
guide to the meaning of a disputed term.’”[citation omitted]).
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Application 10/341,617

The seals in both Grevstad and McPheeters appear to function as a
single manufactured gasket placed at an interface between two components
of a fuel cell. (FF 5 and 6). Thus, the seals taught by Grevstad and
McPheeters appear to be well within the scope of the gasket-type “seal” as
claimed and construed based on the Appellants’ Specification.
Next, we consider the scope and content of the teachings of
Cubukcu. The teachings of Cubukcu with respect to the use of aerogels is
limited to the use of aerogel insulation “provided surrounding the shell 24.”
(FF 7). Although Cubukcu teaches that the aerogels are provided “[t]o
ensure sealing surrounding the incoming air and exhaust openings” (FF 7),
Cubukcu also discloses the use of other materials, such as a foil patch,
Interam™, and silicone rubber RTV to form seals around air or fuel inlets
and exhaust openings. (FF 8 and 9). The clearest examples of seals in
Cubukcu that function most like the gasket seals of Grevstad and
McPheeters are made from other materials, and not the aerogel insulation.
(FF 8 and 9). For example, the gasket-type seal 168 located between the
incoming duct 146 and an exhaust cap 170, as illustrated in Figure 26C, is
made of Interam™ rather than aerogel. (FF 9).
We note that aerogels were known to be porous and permeable. (FF
4). We also note that low fluid permeability is a desired feature for the
gasket-type seals of the present invention. (Spec. ¶ [0029]). Further,
although Cubukcu teaches that the aerogel has very low weight and low
thermal conductivity (FF 7), we find that these characteristics alone would
not have suggested to one of ordinary skill in the art to use the aerogel as a
gasket-type seal in a fuel cell environment.
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Application 10/341,617

The rejection fails because the evidence does not support the
obviousness of using the aerogel taught by Cubucku in the gasket seals
taught by Grevstad or McPheeters. Kahn, 441 F.3d at 988. Thus, the
Examiner has not provided sufficient evidence to establish a prima facie case
of obviousness over claims 38 and 66. Oetiker, 977 F.2d at 1445.
III. CONCLUSION
The Examiner reversibly erred in extrapolating the teachings of
Cubukcu to find that one of ordinary skill in the art would have known to
use an aerogel as a suitable material for the gasket seals taught by Grevstad
or McPheeters. Accordingly, we cannot sustain the Examiner's rejections.
Claims 39-42 and 59-65 are all dependent from claim 38, and the
rejection of these claims fails for the reasons provided above.
Accordingly, we do not sustain the rejection of all the claims.
IV. DECISION
We reverse the Examiner’s decision.

REVERSED

tc

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INTELLECTUAL PROPERTY ADMINISTRATION
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