Callaway Golf Co. v. Acushnet Co.

Callaway Golf Co. (Callaway) (defendant) owned four patents for three-layer golf balls having polyurethane outer covers with on-the-ball, Shore D hardness of no greater than 64. At the time of invention, three-layer and polyurethane-covered golf balls were separately known in the art, and golf-ball hardness was measured on a standard scale identified by the size of an indentor used for the measurement—type A, B, C, D, etc. Callaway sued Acushnet Co. (Acushnet) (plaintiff), alleging balls sold by Acushnet infringed the four patents. Acushnet presented evidence of known three-layer balls without polyurethane covers, arguing the art invalidated the patents for obviousness. None of the evidence presented expressly disclosed the requisite cover hardness; however, Acushnet argued that one of the three-layer ball references implicitly taught the requisite hardness by incorporation of a reference that taught polyurethane outer covers having a Shore C hardness that necessarily converted to the requisite Shore D hardness. The district court construed the term “cover layer having Shore D hardness” to mean hardness measured on-the-ball versus off-the-ball, which is significant because the two measures of the same ball can be different, according to expert testimony. Other testimony provided that cover hardness depends on the composition of layers beneath the outer cover and that Acushnet’s evidence to support conversion of the Shore C to Shore D hardness called into question the accuracy of such a conversion. After a trial on obviousness, a jury returned a verdict that eight of Callaway’s asserted claims were not invalid for obviousness. The district court refused to grant judgment as a matter of law (JMOL) in favor of Acushnet that the asserted claims would have been obvious.