Appeal No. 2004-1043
Application No. 09/960,907
using an airsweep and a controller to control the airsweep
in view of the secondary references.
B. The Weaver Reference
i. The instant invention is patentable over the
combination of the Beck paper and the Weaver reference due
to differences in structure (XII. B, pages 2U-23)
Appellant has argued several structural differences
between the cell used in the, Beck paper and the cell
taught by Weaver, including differences in electrode
structure and heating structure.
Beck teaches a method for the electrolytic production
of aluminum from alumina. Beck teaches the structure of
the electrolytic cell, including the orientation and
structure of the anodes and cathodes, as well as the use of
an anodic liner (figs. 9-11). Like Beck, Weaver also
teaches the electrolytic production of aluminum from
alumina using anodes and cathodes.
Regarding claims 1-17, the Weaver reference also
teaches a method of advantageously using off-peak power by
intermittently operating the electrolytic cell and applying
heat to prevent the freezing of the bath when the power is
not supplied (see US ‘340, p. 3, col. 2, lines 61-74).
Therefore, one of ordinary skill in the art would have been
motivated to operate the, electrolytic cell of Beck
intermittently to take advantage of off-peak power as
taught by Weaver. One skilled in the art would have heated
the electrolyte to maintain the electrolyte in molten state
as taught by Weaver to "prevent the freezing of the bath to
a hard stone-like substance which would cause damage to the
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