Addressing the issue of claim construction in the context of summary judgment, the U.S. Court of Appeals for the Federal Circuit affirmed a district court’s summary judgment of infringement in the course of reversing the district court’s finding that there was no literal infringement.  The Federal Circuit found that the district court unduly limited the scope of a disputed claim term.  Cheese Systems, Inc. v. Tetra Pak Cheese & Powder Systems, Inc., Case No. 12-1463, -1501 (Fed. Cir. Aug. 6, 2013) (Rader, C.J.)

This declaratory judgment suit between patentee Tetra Pak Cheese and Cheese Systems, Inc., (CSI) involved a patent directed to commercial cheese-making vats having agitator panels driven by long shafts.  Agitator panels have two faces, one side with sharp edges for cutting, and the other side with blunt edges for stirring.  The patent requires each face to be “disposed in a generally common . . . plane.”

The district court construed the “generally common plane” limitation to require panel faces to be “on the whole flat but include some degree of curvature.”  The cutting face of the CSI panels formed a concave surface while the stirring face formed a roughly parallel convex surface on the opposite side as demonstrated by photographs and design specifications in the record.  Holding that no reasonable jury could conclude that the CSI panels were “on the whole flat,” the district court denied Tetra Pak’s motion for summary judgment of literal infringement.  The district court concluded, however, that the curved panel faces operated in substantially the same way as flat panel faces, and granted summary judgment of infringement based on the doctrine of equivalents.  CSI appealed the district court’s finding of infringement based on the doctrine of equivalents. 

The Federal Circuit, however, did not reach the issue of equivalents.  Instead, based in part on its review of photographs of the accused product in the record, the Federal Circuit reversed the district court’s denial of summary judgment of no literal infringement.  The Federal Circuit held that the district court’s construction of “generally common plane” was too restrictive.  The Federal Circuit found that the limitation “d[id] not require the panel to have any particular shape.”  With its broader construction, the Federal Circuit concluded that CSI’s panel faces were “in the same plane” as required by the “generally common plane” limitation.

Practice Note: While information about an accused product is typically given no weight during claim construction, the Federal Circuit based its construction and finding of literal infringement ruling, at least in part, on photographs of the accused product.  Thus, even in the context of claim construction, it may be worth considering including information about the accused product to give the court context for its construction of a claim term and/or the infringement analysis.