Appeal No. 2002-2329 Page 5
Application No. 09/647,815
that it would have been obvious to one of ordinary skill in the art to modify Cullen to
meet the terms of claim 1 in view of the teachings of Takeshima. In this regard, the
appellant first points out that the Takeshima is different than that of Cullen in that
Takeshima utilizes an SOx absorbent upstream of an NOx absorbent to keep the latter
from accumulating SOx therein. The appellant goes on to argue that Takeshima
discloses purging the SOx from the SOx absorbent and the NOx from the NOx
absorbent at normal operating temperatures (see column 1, line 60 - column 2, line 14)
without injecting air into the exhaust stream, and there is no teaching in either reference
that the use of the two operating parameters (81 and 82) disclosed in Takeshima for
SOx removal at normal operating temperatures will also work for high temperature
purging of SOx from a NOx storage catalytic converter.
For the reasons expressed in the Brief and the Reply Brief, we agree with the
appellant that the examiner’s rejection should not be sustained. Takeshima provides
two separate absorbing traps, one for removing NOx and a second, upstream of the
first, for removing SOx. Even if one acknowledges that Takeshima operates the engine
during a particular time period so as to produce an 82<1 but greater than 81 to purge the
SOx from the SOx trap at normal operating temperatures, there is no evidence to
support the examiner’s position that it would have been obvious to add such a feature
to the Cullen system, which has only the single NOx converter and which teaches
purging the SOx from a NOx converter at an elevated temperature. We are not
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