Appeal 2006-2987
Application 10/661,651
suggestion, or motivation from within the art for using chemical milling to
accomplish rotational balancing of blisks. The APA recognizes that dealing
with the balancing problem requires appropriate assessment of where and to
what degree the imbalance exists and that this is done using conventional
machines to measure the imbalance and then correcting the imbalance by
removing blisk material (Specification ¶ 0007), the traditional removal
method being one of mechanical machining or milling (Specification ¶
0006). Chemical milling, according to Walker, was a known alternative to
the more traditional mechanical milling technique (Walker, p. 511, col. 1).
Chemical milling like mechanical milling serves to remove material from
the metal workpiece. When faced with the problem of removing metal to
balance blisks, one of ordinary skill in the art would have selected chemical
milling because, as discussed by Walker, chemical milling removes material
to exacting tolerances, has low tooling costs, and does not result in burrs.
We find that the Examiner has provided the necessary evidence to
support the Examiner’s finding.
We conclude that the Examiner has established a prima facie case of
obviousness with respect to the subject matter of claim 9 that has not been
sufficiently rebutted by Appellants.
3. Claim 10
Claim 10 was also rejected by the Examiner over either the APA or
Lowe in view of Walker. Claim 10 is dependent on claim 9 and further
requires a step of determining if the blisk is balanced and, if not balanced,
repeating one or more of the steps of balancing until the blisk is balanced.
Appellants contend that in rejecting claim 10 the Examiner has made
an unsupported conclusory statement that it would have been obvious “to
9
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