The safe harbour provision of Title 35, Section 121 of the US Code offers crucial protection for divisional applications filed in response to restriction requirements, shielding them from non-statutory double patenting rejections based on patents or applications within the same family. Understanding when this protection applies is essential for maintaining patent term adjustment (PTA), avoiding terminal disclaimers, and developing effective prosecution strategies.
Non-statutory double patenting is a judicially created doctrine designed to prevent applicants from obtaining multiple patents claiming obvious variations of the same invention, thereby improperly extending the effective patent term. When two patents from the same family claim subject matter that is not patentably distinct, a non-statutory double patenting rejection typically requires filing a terminal disclaimer, which ties the patent term to that of the earlier patent and can result in loss of PTA, thereby shortening the overall life the patent would have had without the terminal disclaimer.
The safe harbour provision addresses a fundamental tension in this framework. When the USPTO requires an applicant to divide an application through a restriction requirement, the applicant should not be penalised for complying with that requirement. The statute provides that a patent issuing from an application in which restriction was required cannot serve as the basis for a non-statutory double patenting rejection against a divisional application filed in response to that requirement, provided the divisional was filed before the patent issued.
Scope and requirements for protection
The protection afforded by Title 35, Section 121 of the US Code is narrowly tailored. The Federal Circuit has made clear that safe harbour extends only to divisional applications, not to continuation or continuation-in-part applications. The Federal Circuit has also confirmed that safe harbour protection cannot be recovered retroactively by amending a continuation-in-part patent to delete new matter and redesignating it as a divisional.
For safe harbour protection to apply, three fundamental requirements must be satisfied:
The USPTO must have made a formal requirement for restriction between independent and distinct inventions. Voluntary filing of multiple applications without such a requirement does not trigger protection.
The restriction requirement must remain in force through issuance of the patent. If the examiner withdraws the restriction requirement before the patent issues, the safe harbour disappears.
The divisional application must be filed before the patent issues from the application containing the restriction requirement.
Claims must be formally entered, restricted, and removed from the earlier application before being filed in the divisional. Claims never formally entered in the original application do not receive safe harbour protection, even if the original application provided support for such claims.
The consonance requirement
Safe harbour protection depends on maintaining consonance between the claims actually restricted and the claims prosecuted in the divisional application. The line of demarcation between independent and distinct inventions identified by the examiner in the restriction requirement must be maintained throughout prosecution.
When claims in the divisional application materially differ from those subject to the restriction requirement, consonance is lost and safe harbour protection disappears. If the divisional includes claims broader in scope than the restricted claims or adds claims to subject matter not encompassed by the original restriction groups, these non-consonant claims fall outside the safe harbour’s protection.
Applicants must carefully track the scope of restricted claims and ensure that amendments in the divisional application do not expand beyond the boundaries established by the restriction requirement. Material changes to claim scope can inadvertently forfeit safe harbour protection.
Key exceptions where safe harbour does not apply
Continuation applications filed from a parent with a restriction requirement do not automatically carry forward that protection unless the examiner reinstates or refers to the restriction requirement in the continuation. If the continuation proceeds without the examiner making or referring to a restriction requirement, a patent issuing from that continuation can be used as the basis for a double patenting rejection against a later-filed divisional.
When the examiner issues a restriction requirement subject to the non-allowance of generic or linking claims, and such generic claims are subsequently allowed, safe harbour protection does not apply. Similarly, lack of unity determinations made during the international phase do not trigger safe harbour protection for later-filed US applications, though restriction requirements made by the USPTO examiner in national stage applications submitted under Title 35, Section 371 of the US Code do provide protection.
The safe harbour does not protect against statutory double patenting rejections under Title 35, Section 101 of the US Code when claims to identical subject matter appear in both applications.
Strategic implications
The safe harbour provision creates important opportunities for patent prosecution. When a restriction requirement is made, thoughtful response can preserve valuable options while avoiding pitfalls.
Accepting a restriction requirement and filing a divisional application secures safe harbour protection, but only if consonance is maintained. Applicants should carefully document the scope of restricted claims at the time of election and ensure that amendments in both parent and divisional applications remain consonant with the restriction groups as originally defined.
Continuation applications present particular challenges. Practitioners should request that examiners reinstate restriction requirements in continuation applications when safe harbour protection is important to the overall family strategy. Without reinstatement, a patent issuing from the continuation can serve as a double patenting reference against divisional applications filed later, despite the earlier restriction requirement.
Preserving patent term adjustment
The practical importance of safe harbour protection often centres on preserving patent term adjustment. When a non-statutory double patenting rejection cannot be overcome on the merits, filing a terminal disclaimer resolves the rejection but commonly results in loss of PTA. The safe harbour provision allows divisional applications to avoid this outcome entirely when the requirements are met.
For applicants managing patent families where PTA represents significant value, ensuring that safe harbour protection applies can be worth substantial effort. Maintaining consonance, filing divisionals before parent patents issue, and carefully tracking restriction requirements across divisional applications all contribute to preserving this valuable protection.
