Unnecesary Arguments Still Can Create an Estoppel

Pods, Inc. v, Porta Stor, Inc., [06-1504](April 27, 2007)[DYK, Lourie, O'Malley] The Federal Circuit reversed judgment of infringement of U.S. Patent No. 6,071,062 because of an error in claim construction, and prosecution history estoppel, which precluded infringement under the doctrine of equivalents.
SIGNIFICANCE: Claim terms have the same meaning throughout the claims, and even unnecessary arguments to distinguish the claims create an estoppel.
BRIEF: The claims at issued required positioning a carrier frame around a container, which the Trial Court interpreted to mean that "carrier frame" was not limited to a four-sided, rectangular shaped frame, and that "around" meant on all four sides or on less than all four sides, and granted JMOL of infringement. The Federal Circuit began its construction of claim 29 "with the words of the claims themselves." The Federal Circuit was not limited to the claim at issue, because other claims of the patent in question, both asserted and unasserted, are valuable sources of enlightenment as to the meaning of a claim term." Noting that its was agreed tha th term "carrier frame" in claim 1 meant a four-sided or rectangular frame, the Federal Circuit relied upon the presumption that the same terms appearin in different portions of the claims should be given the same meaning unless it is clear from the specification and prosecution history that the terms have different meanings at different portions of the claims. Based upon this construction the Federal Circuit found no literal infringement. Turning the infringement under the doctrine of equivalents, the Federal Circuit noted that when a patent applicant sets forth multiple bases to distinguish between its invention and the prior art, the separate arguments can create separate estoppels as long as the prior art was not distinguished based on the combination of these various grounds. However to invoke argument-based estoppel the prosecution history must evince a clear and unmistakable surrender of the subject matter. Examinng the prosecution history, the Federal Circuit found that each argument made by the patentee created a separate estoppel. The patentee argued that the arguments were not necessary to distinguish the prior art, but the Federal Circuit said that clear assertions made during prosecution in support of patentability, whether or not actually requied to secure allowance of the claim, amy also create an estoppel. In response to the argument that claim 32 was added after the limiting arguments, the Federal Circuit noted that one an argument is made regarding a claim term so as to create an estoppel, the estoppel will apply to that term in other claims.
CANONS: Claim terms are presumed to have the same meaning through the claims.
COMMENT: The Federal Circuit overlooked the fact that other language in claim 1, not present in claim 29, was responsible for the narrow meaning of the term in claim 1. Thus the rule that claims terms have the same meaning does not require that claim 29 be limited to a four sided or rectangular frame.