Appeal No. 97-1078
Application 08/448,056
Oda pertains to ceramic honeycomb heat exchangers. Of
the particular ceramic materials to be used, Oda teaches that
materials having high heat resistance and thermal
shock resistance are preferable for effectively
utilizing the heat exchange of the hot fluid.
Ceramic materials having low thermal expansion, such
a[s] cordierite, mullite, magnesium aluminum
titanate, silicon carbide, silicon nitride and a
combination of these materials are desirable. These
materials are excellent in heat resistance and are
small in thermal expansion coefficient . . . so that
these materials can endure rapid temperature . . .
change [column 2, lines 49 through 59].
In combining Davies and Oda to support the rejection of
claim 12, the examiner concludes that it would have been
obvious at the time the invention was made to a person having
ordinary skill in the art “to employ in the appropriate
portion [13M] of Davies et al. known regenerator construction
material such as cordierite . . . for the purpose of obtaining
high heat resistance and thermal shock resistance as disclosed
in Oda et al.” (main answer, page 4). The examiner further
explains that
[t]he middle layer (13M) or [sic, of] the
regenerator of Davies et al. is made from a material
(forsterite, see column 2, lines 27-29) selected for
its resistance to heat and low expansion
property/low temperature shock. Forsterite is known
in the ceramics art to have a low expansion
coefficient which is in the range of the low
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