Dunlop was seeking to patent a new golf ball core design for a rubber core that improved flight time. Specifically, Dunlop was seeking to protect a new core design where the core was formed by a crosslinked rubber composition including (a) a base rubber; (b) a co-crosslinking agent; (c) a crosslinking initiator; and (d) an acid and/or a salt. The Patent Office could not find this combination in the golf ball arts, but did find a reference having elements a-c, and a second golf ball patent application that included element (d) in a different type of core.

Dunlop appealed the rejection and one of the issues on appeal was whether there were unexpected results achieved by the combination of features. Generally, the Patent Office will have established a proper rejection if they can articulate a reason to combine the features. Here, the Office argued that the secondary reference indicated a benefit to using the acid/salt in a golf ball core as to improving the dispersion of the coagent into the elastomer matrix. Dunlop argued that their purpose for including element (d) was to form a linear hardness distribution in the core to improve flight time/distance.

However, at the Patent Office, once the Examiner provides a valid reason for combining the references, the burden shifts to the applicant in order to prove the unexpected results. Here, Dunlop offered arguments but with insufficient evidence. For example, Dunlop could have shown how the acid or salt had an unexpectedly disproportional impact on the hardness distribution through test data of samples, and then provided further data showing how this impacts flight time. But, without actual evidence, Dunlop came up short and the decision to reject the application was affirmed by the Board of Appeals. 

So, if you have combined known elements in a new way that achieves an expected performance benefit, make sure to document this finding with actual test data so that you don't find yourself in a sand trap at the USPTO.