Saro Golf, Inc. v. Nike, Inc., No. 08 C 1110, Slip Op. (N.D. Ill. Sep. 9, 2013) (Chang, J.).

Judge Chang clarified the claim constructions in this patent case regarding an improved golf club head.  “Radius of curvature” was previously construed to mean “radius of a substantially circular curve of a substantial portion of the back side profile shape.”  This construction presumed that each of the heel and toe of a club head had a profile that was “circular in profile” meaning that it was largely made of a single radius.  Neither party had sought a construction limiting the profile to one composed of a single radius, nor did they address the construction at the claim construction hearing.

The Court considered the parties’ briefs and the intrinsic evidence, but could not “square” the construction with the evidence because:

  1. The single radius requirement read one of the preferred embodiments out of the claim.
  2. The construction was a “mouthful” and did not make sense grammatically within the asserted claim 7.  It is good to see courts concerned with making claims that could go to a jury more reasonable and understandable, although it may be a nearly impossible task.
  3. The prior construction was based upon the faulty premise that a radius of curvature could only be a circle.  In fact, it is a mathematical term that can be applied to any curve.

The Court, therefore, held that the Radius of Curvature was an average measure along a complex curve, and the issue was where it was measured from.  The Court ordered further briefing on the issue because neither party fully addressed it.

The Court also upheld the prior constructions of “Heel” and “Toe” of the club.  In doing so, the Court cautioned defendants to strongly consider offering alternative constructions when arguing terms were indefinite to avoid leaving the Court “at sea” should indefiniteness be denied.  The Court acknowledged that offering a construction could weaken the indefiniteness argument, but pointed out that courts regularly handle arguments in the alternative.