C. W. Zumbiel Co., Inc. v. Kappos

A patent claim's preamble is a limitation if it is essential to understand limitations or terms in the claim body.

Opinion (Wallach): C.W. Zumbiel Co., Inc. requested reexamination of Graphic Packaging International, Inc.’s Patent No. 6,715,639 (‘639), relating to a carton or box that holds containers like cans and bottles. Following reexamination of the patent, the Board of Patent Appeals found some of the patent claims invalid for obviousness, and held that another claim was patentable. Both Zumbiel and Graphic appealed. The Board found prior art in two of the patents. Of the claims held obvious, each was a variation of claims included in the prior art. Because the Federal Circuit determined that the Board’s underlying factual findings were supported by substantial evidence, and because those findings indicated that Graphic’s claimed invention would have been obvious to a person skilled in the art, the Court upheld the Board’s decision to invalidate the relevant claims. Zumbiel also argued that the preamble of some of the claims could not be used to determine the patentability of their dependent claims with respect to the prior art. Because a term in the body of the disputed claim depended on the preamble, the Appeals Court AFFIRMED the Board’s decision to consider the preamble as a limitation.