American Axle & Manufacturing, Inc. v. Neapco Holdings LLC, No. 18-1763 (Fed. Cir. 2019)Annotate this Case
AAM’s 911 patent generally relates to a method for manufacturing driveline propeller shafts with liners that are designed to attenuate vibrations transmitted through a shaft assembly. Propshafts are employed in automotive vehicles to transmit rotary power in a driveline. The patent identified a need for an improved method for damping various types of vibrations in a hollow shaft; AAM argued that the inventive concept to which the claims are directed is the tuning of a liner in order to produce frequencies that dampen the shell mode and bending mode vibrations simultaneously. In AAM’s infringement action against Neapco, the district court granted Neapco summary judgment, holding that the asserted claims are patent-ineligible under 35 U.S.C. 101. The Federal Circuit affirmed. The claims’ direction to tune a liner to attenuate to different vibration modes amounted to merely instructing one to apply Hooke’s law to achieve the desired result of attenuating certain vibration modes and frequencies without providing a particular means of how to craft the liner and propeller shaft in order to do so. Hooke’s law is a natural law, an equation that describes the relationship between an object’s mass, its stiffness, and the frequency at which the object vibrates.