Because we affirm the district court’s constructions of “board” and “manufactured to have,” we affirm the district court’s grant of summary judgment of non-infringement of claims 1-15 and 18-20. We reverse the district court’s construction of “convex top surface.” The district court’s summary judgment of invalidity of claims 18-20 of the ’831 patent as anticipated by the Zagelmeyer reference is also reversed. Because the district court did not abuse its discretion, we affirm the district court’s refusal to award sanctions under 28 U.S.C. § 1927 in favor of Nystrom. The case is remanded for further proceedings consistent with this opinion.