Rule Review - Obviousness-Type Double Patenting

The Uruguay Round Agreements Act (URAA), Pub. L. 103-465, 108 Stat. 4809 (effective June 8, 1995), installed a twenty-year U.S. patent term from the earliest-claimed priority date, modifying the previous seventeen-year term calculated from the date of patent issuance.¹  That change eliminated a perceived abuse—sometimes called "submarine patenting" or "evergreening"—wherein the use of continuing applications allowed claiming of previously disclosed features many, many years later, since patent expiration was calculated from the date of issuance.  In that former context, the prohibition against obviousness-type double patenting (OTDP) was a check ensuring that patentees could not obtain more than one patent based on merely unpatentable variations, effectively extending the monopoly on the same basic invention.