Examiner's Amendment to Correct Inadvertent Ommission Did Not Affect DOE

In Conoco v. Energy & Environmental International (August 17, 2006), the Federal Circuit held that an Examiner's amendment to conform the claims with the scope of the applicant's arguments was not for puposes of patentability and did not estopp the application of the Doctrine of Equivalents.

once the applicants cancelled the original claims and submitted 22 new claims, all but the first claim lacked the fatty acid wax limitation—presumably making the new claims broader than originally argued. Nevertheless, the examiner and applicants continued to focus their arguments as if the limitation was present, arguing the difference between fatty acid waxes and metal stearates. Such evidence indicates that the amendment was the correction of an inadvertent omission rather than the intentional narrowing of a broad claim for patentability purposes. Thus, the district court did not err by finding that the claim was not amended for purposes of patentability.