Arguments Create Disclaimers, Even if Made in the Alternative

Anderson Corp. v. Fiber Composites, LLC., [05-1434, 06-1009](January 26, 2007)[BRYSON, Prost, Saris] The Federal Circuit affirmed the construction of a group of four patents, and reversed the construction of a second group of two patents.
SIGNIFICANCE: An applicant's argument can serve as a disclaimer of claim scope, even if the applicant distinguishes the reference on other grounds as well.
BRIEF: The Federal Circuit noted that while nothing on the face of the asserted claims in the first group of patents limited "composite construction" to a particular form, the specification makes clear that the term, as used in the group 1 patents, mus be construed in a limited manner. The Federal Circuit noted that this was not a case where the claims were limited to the preferred embodiment, rather they were limited to how the term "composite construction" was used in the specification. The Federal Circuit quoted from the Field of the Invention, the Abstract, and other parts of the specification. The Federal Circuit said that these statements "are not descriptions of particular embodiments, but are characterizations directed to the invention as a whole." The Federal Circuit rejected arguments to the contrary based upon claim differentiation: "the written description and prosecution history overcome any presumption arising from the doctrine of claim differentiation." The doctrine of claim differentiation can not broaden claims beyond their correct scope, determined in light of the specification and the prosecution history and any relevant extrinsic evidence. "Claims that are written in different words may ultimately cover substantially the same subject matter." The Federal Circuit also pointed out that the claims weren't otherwise identical.
Regarding the second group of claims, the Federal Circuit also found that based upon the specification the claims were limited similarly to the first group. While the patentee argued that the specification was merely describing a preferred embodiment, the Federal Circuit found that the specification used language of requirement, not preference. Recognizing that it has warned against importing limitations form the specification into the claims, the Federal Circuit acknowledged the case would have been a close one, except for the prosecution history, in which the Federal Circuit found clear evidence of disclaimer. The Federal Circuit rejected the argument that there was no disclaimer because the prior art was distinguished on multiple grounds. "An applicant's invocation of multiple grounds for distinguishing a prior are reference does not immunize each of the form being used to construe the claim language. Rather, as we have made clear, an applicant's argument that a prior art referee is distinguishable on a particular ground can serve a disclaimer of claim scope even if the applicant distinguishes the reference on other grounds aw well." has