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Diamond v. Diehr

Supreme Court of the United States

October 14, 1980, Argued ; March 3, 1981, Decided

No. 79-1112


 [*177]  [***160]  [**1052]    JUSTICE REHNQUIST delivered the opinion of the Court.

 We granted certiorari to determine whether a process for curing synthetic rubber which includes in several of its steps the use of a mathematical formula and a programmed digital computer is patentable subject matter under 35 U. S. C. § 101.

The patent application at issue was filed by the respondents on August 6, 1975. The claimed invention is a process for molding raw, uncured synthetic rubber into cured precision products. The process uses a mold for precisely shaping the uncured material under heat and pressure and then curing the synthetic rubber in the mold so that the product will retain its shape and be functionally operative after the molding is completed. 2

 [****6]  Respondents claim that their process ensures the production of molded articles which are properly cured. Achieving the perfect cure depends upon several factors including the thickness of the article to be molded, the temperature of the molding process, and the amount of time that the article is allowed to remain in the press. It is possible using well-known time, temperature, and cure relationships to calculate by means of the Arrhenius equation 3 when to open the press  [*178]  and remove the cured product. Nonetheless, according to the respondents, the industry has not been able to obtain uniformly accurate cures because the temperature of the molding press could not be precisely measured, thus making it difficult to do the necessary computations to determine cure time. 4 [****8]  Because the temperature inside the press has heretofore been viewed as an uncontrollable variable, the conventional industry practice has been to calculate the cure time as the shortest time in which all parts of the product will  [***161]  definitely be cured, assuming a reasonable amount of mold-opening time during loading and unloading. But the shortcoming of this practice is that operating with [****7]  an uncontrollable variable inevitably led in some instances to overestimating the mold-opening time and overcuring the rubber, and in other instances to underestimating that time and undercuring the product. 5

Respondents characterize their contribution to the art to reside in the process of constantly measuring the actual temperature inside the mold. These temperature  [**1053]  measurements are then automatically fed    into a computer which repeatedly recalculates the cure time by use of the Arrhenius equation.  [*179]  When the recalculated time equals the actual time that has elapsed since the press was closed, the computer signals a device to open the press. According to the respondents, the continuous measuring of the temperature inside the mold cavity, the feeding of this information to a digital computer which constantly recalculates the cure time, and the signaling by the computer to open the press, are all new in the art.

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450 U.S. 175 *; 101 S. Ct. 1048 **; 67 L. Ed. 2d 155 ***; 1981 U.S. LEXIS 73 ****; 209 U.S.P.Q. (BNA) 1; 49 U.S.L.W. 4194



Disposition:  602 F.2d 982, affirmed.


patent, cure, invention, temperature, press, algorithm, rubber, molding, calculation, subject matter, programmed, machine, computer program, digital computer, patentable subject matter, mathematical, discovery, equation, mathematical formula, respondents', formula, novel, processes, novelty, patent application, alarm, steps, unpatentable, synthetic rubber, measuring

Patent Law, Utility Patents, Product Patents, Compositions of Matter, Process Patents, General Overview, Machines, Manufactures, Governments, Legislation, Interpretation, Jurisdiction & Review, Standards of Review, Elements, New Uses, Computer Software & Mental Steps, Principles & Results, Computer & Internet Law, Intellectual Property Protection, Patent Protection, Subject Matter, Anticipation & Novelty, Description in Prior Patents, Combinations