Knowledge of a person of skill in the art was recently used to revive claims that had earlier been found indefinite under 35 U.S.C. § 112. Delaware District Court Judge Leonard P. Stark granted a motion for reargument on the issue of patent indefiniteness after considering evidence of a person skilled in the art. Judge Stark held there to be a factual dispute regarding the knowledge that a person of skill in the art would bring to bear when testing for features claimed in US Patent Nos. 7,774,911 and 8,176,613. The factual dispute determination precluded a conclusion, until the dispute is resolved, that it has been proven by clear and convincing evidence that the claims are invalid. American Axle & Manufacturing, Inc. v. Neapco Holdings LLC and Neapco Drivelines LLC, C.A. No. 15-1168-LPS (D. Del. September 6, 2017).
US Patent Nos. 7,774,911 and 8,176,613 were asserted by American Axle & Manufacturing, Inc. (“AAM”) against Neapco Holdings LLC and Neapco Drivelines LLC (“Neapco”). Claims of each of the patents include the step of positioning a liner within a driveline shaft member to:
Neapco argued that those claims are invalid as indefinite for failing to establish test conditions for use in determining (for above item 1) the degree of damping, and (for above item 2) the natural frequencies of vibration. AAM countered that a person of skill in the art would be able to select appropriate conditions for such evaluations. Key among those testing conditions was the testing temperature, central to Neapco’s argument on claim construction and the court’s previous determination that the terms are indefinite.
Factors considered by the court in assessing indefiniteness included an assessment of support in the specification for the claims, and, when such support was lacking, evidence of relevant knowledge of a person of skill in the art – in this case, the art of driveshaft testing. In making its earlier (April 7, 2017) decision finding indefiniteness, the court looked to precedent established by:
The technical witnesses (two engineers from each side) consistently testified that such testing would be conducted at room temperature, and more particularly that they had performed such testing at room temperature.
The court was persuaded by the testimony to revise its April 7 decision, finding that a person of skill in the art might know that testing should occur at room temperature, and that there was at least enough evidence to establish a factual dispute on the test temperature.
Lessons for Practice
This case illustrates that reliance on knowledge attributable to a person of skill in the art to overcome indefiniteness is not dead. The case also illustrates that care should be taken in drafting descriptions that are complete and enabling to a person of skill in the art.