A Claim Construction Excluding The Preferred Embodiment Is "Rarely, If Ever, Correct"

Patent applications that describe a "preferred embodiment" often include claims directed to that embodiment.  After all, if an embodiment is "preferred," it is likely worthy of claim coverage.  Nevertheless, applicants are not required to focus their claims on a preferred embodiment; they are free to claim any alternative embodiments described in the specification.  A special issue of claim construction arises, however, when an application describes a "preferred embodiment," but a question is raised as to whether that embodiment is covered by the claims.

The Court of Appeals for the Federal Circuit recently considered this issue in Accent Packaging, Inc. v. Leggett & Platt, Inc., No. 2012-1011 (Fed. Cir. Feb. 4, 2013).  In the district court, Accent alleged that Leggett infringed U.S. Patent Nos. 7,373,877 ("the '877 patent") and 7,412,992 ("the '992 patent").  The patents, which are related and have nearly identical specifications, describe and claime a wire tier