Case 10: Diamond v. Diehr (1981)

Diamond and his crew filed a petition for a patent which would mold raw rubber into precise shapes. This process had been difficult in the past because of the uncertainty surrounding the proper curing time. This uncertainty stemmed from the fact that determining the temperature inside the molding press was problematic. The cure time is related to the temperature by a known mathematical formula; the respondents developed a system by which the temperature inside the press was continuously fed into a computer program that would automatically open the press at the right time. They were at first denied a patent, but the court later held that they were in fact entitled to a patent.

This case cited the Cochrane case, which defined a process as "an act, or a series of acts, performed upon the subject-matter to be transformed and reduced to a different state or thing. If new and useful, it is just as patentable as is a piece of machinery .... The machinery pointed out as suitable to perform the process may or may not be new or patentable."