What is a divisional application?

While divisional and continuations are practically synonymous, a "divisional" technically refers to a child application containing originally filed claims that were not pursued in the parent application. A common example is a parent application that originally included both apparatus and method claims. In response to a Restriction Requirement in which the patent examiner requires the applicant to choose one or the other, the applicant may, for example, elect apparatus claims in the parent and then file a divisional to pursue the non-selected method claims.

How can an applicant make strategic use of parent and child patent applications?

Continuations can also play an important role in an effective patent enforcement strategy. If a parent patent has been granted, an applicant may want to consider filing a continuation application prior to the grant of the parent patent in order to catch competitors attempting to design around the parent patent claims.

For example, if a parent patent issues with an independent claim covering ABC and a competitor introduces a new product with only AB (no C), filing a continuation with claims covering only AB (assuming such a claim is allowable over the prior art and supported by the specification) provides the patent owner with a second chance to capture the design-around attempts.

A strong patent with well-drafted claims may still be vulnerable to design-arounds. Once competitors have analysed and disassembled the patent claims, it is impossible to predict how they will engineer around the claims to avoid infringement.

While it is unknown how third parties will design around allowed claims, filing a continuation application with a placeholder claim allows the patent owner to observe how the competition responds to the granted patent. The patent owner may then file a preliminary amendment to replace the placeholder claims with new claims that capture any design-around products more effectively.