District Court Revisits Claim Construction On Motion For Summary Judgment Of Indefiniteness
IP Litigation
This links to the home page
  • District Court Revisits Claim Construction On Motion For Summary Judgment Of Indefiniteness

    On June 30, 2022, Judge Noreika of the Federal District Court for the District of Delaware denied defendants’ motion for summary judgment that certain asserted claims were indefinite and modified her construction of the term that formed the basis of defendants’ indefiniteness argument.  Chemours Company FC, LLC v. Daikin Industries, Ltd., Case No. 17-1612, (D. Del. June 30, 2022).

    The patent at issue, U.S. Patent No. 7,122,609, recites “a melt flow rate of within the range of about 30±3 g/10 min.”  During claim construction, plaintiff Chemours urged, and the Court adopted, a construction of “melt flow rate” that did not require any specific measurement conditions or methods.  That prompted defendants to move for summary judgment that the claims were indefinite because there were multiple ways to measure melt flow rate, leaving a person of ordinary skill in the art (POSITA) unable to determine what the ’609 patent requires.

    At the summary judgment hearing, however, Chemours argued that a POSITA would understand that melt flow rate is determined by the ASTM standard.  Citing Federal Circuit precedent, the Court found that it could engage in “rolling claim construction” and could revisit claim construction as the case progresses.  The Court found it appropriate to revise its claim construction of “melt flow rate” to reference the ASTM standard, thus mooting defendants’ motion for summary judgment of indefiniteness.

    The Court also rejected defendants’ argument that the doctrine of equivalents was unavailable because the claim language included words of approximation (i.e., “about”).  In fact, the Court pointed out, “the Supreme Court’s decision confirming the vitality of the doctrine of equivalents, Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17 (1997), addressed equivalents of a claim term requiring a pH of ‘approximately 6.0 to 9.0.’”  The Court found no support for defendants’ argument that, as a matter of law, words of approximation precluded applying the doctrine of equivalents.

    Finally, the Court denied defendants’ motion for summary judgment of no literal infringement, finding the question of whether the accused products’ 35.0 or greater flow rate was “about 30±3 g/10 min” presented a “battle of the experts.”
    CATEGORY: Claim Construction