Appeal 2006-2987
Application 10/661,651
Lowe with the teachings of Walker (Br. 6-7). The Examiner responds that
there is a basis in the prior art for the finding of a motivation (Answer 8-9).
Therefore, the dispositive issue is: Has the Examiner established, by a
preponderance of the evidence, a reason, suggestion, or motivation
originating from within the prior art for combining the teachings of the
applied references?
The issue before us turns on the facts. The following facts are
undisputed.
Lowe describes a process of mechanical milling gas turbine engine
blisks. According to Lowe, conventional mechanical milling and
electrochemical machining (ECM) processes result in variations from blade-
to-blade which must be corrected by balancing (Lowe, col. 1, l. 46 to col. 2,
l. 65). This balancing process involves milling selected blades of the blisk in
order to remove material to balance the blisk (Lowe, col. 2, ll. 61-64).
Furthermore, in the conventional methods, because the blades are
freestanding or radially cantilevered, they elastically deflect under the force
of the semi-finishing ball mill (Lowe, col. 2, ll. 34-41). The corrections that
must be made to accommodate the deflection increase milling time (Lowe,
col. 2, ll. 41-44).
The APA includes a disclosure similar to that in Lowe (Cf.
Specification ¶ 0004-0006). Like Lowe, the APA discloses that “[a] gas
turbine blisk is typically manufactured from a one piece solid forging which
is conventionally machined using either mechanical machining (mechanical
milling) or electrochemical machining (ECM) (Specification ¶ 0004).
However, due to manufacturing tolerances and the inherent variation within
the manufacturing processes, there are typically differences in the
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