Restriction Requirements, Double Patenting, And Finding The Safe Harbor

Restriction requirements under 35 U.S.C. § 121 arise during examination at the U.S. Patent and Trademark Office (USPTO) when an examiner determines that an applicant is pursuing multiple, patentably distinct inventions within the same application. The examiner's determination, however, may not always be in agreement with that of a court. In litigation, an accused infringer may assert that the patentee pursued the same or obviously similar inventions in multiple applications, one or more of which later issued as the patent-in-suit. A finding of double patenting can invalidate the offending claims. To account for this possible anomaly, 35 U.S.C. § 121 includes a safe harbor against double patenting, whereby "[a] patent issuing on an application with respect to which a requirement for restriction under this section has been made, or on an application filed as a result of such a requirement, shall not be used as a reference . . . against a divisional application or against the original application or any patent issued on either of them, if the divisional application is filed before the issuance of the patent on the other application."

Satisfying the safe-harbor provision requires that the divisional application maintain "consonance" with the parent and other reference patent. This judicially created consonance concept specifies that the "line of demarcation between 'independent and distinct inventions' that prompted the restriction requirement be maintained." Gerber Garment Tech., Inc. v. Lectra Sys., Inc., 916 F.2d 683, 688 (Fed. Cir. 1990). In other words, for the safe harbor to apply, a "divisional application filed as a result of a restriction requirement may not contain claims drawn to the invention . . . elected and prosecuted in the parent application." Id. at 687. While this concept seems clear in practice, its application can be complicated for more complex patent families.

The Court of Appeals for the Federal Circuit recently considered the scope of the safe-harbor provision for a family of four patents in St. Jude Medical, Inc. v. Access Closure, Inc., No. 12-1452 (Fed. Cir. Sept. 11, 2013). In the district court, St. Jude brought suit against Access Closure alleging patent infringement. The jury found that the claims-at-issue were invalid for double patenting.

The patent-in-suit was part of a family including a grandparent, parent, and one sibling. The examiner of the grandparent application had concluded that its claims were drawn...