A continuation patent application is a patent application that continues the examination of the application. It enables you (the applicant) to continue to argue with the USPTO for a broader (or different) scope of patent protection while the original patent application issues. The original application is often referred to as the parent and the successive applications are referred to as children. The claims in a continuation patent application have the priority date of the parent patent application. Importantly, any continuation must be filed before the issuance or abandonment of the parent application.
Filing a continuation is a way to take a single patent application and turn it into two or more patents. There are a few reasons that you may wish to file a continuation, each relating to increasing the strength of the patent portfolio. A reason not to file a continuation is to avoid additional expense, but avoiding additional expense can be a good reason not to proceed.
A first reason to file a continuation is to increase the scope of patent protection. Having a single patent claiming an invention from a single perspective is valuable, but the underlying invention may be even better protected by having multiple patents claim the invention from multiple perspectives. A “design around” of one set of claims in a first patent may not be a design around of the claims in the second patent. Or designing around a first and second set of claims may not get around a third set. Of course, theoretically there is no limit to the number of continuation applications (and resultant patents) that may come from a single original patent filing, but there is some practical limit since you don’t want to spend your entire budget pursuing an endless family of patents.
A second reason to file a continuation is to keep the outer scope of the claims ambiguous. When a patent application is pending, the scope of the claims that will issue is indeterminate. That ambiguity prevents competitors from reliably knowing exactly how to avoid infringing the claims that will issue when the patent is allowed. However, once a patent has issued, the claims lay out clear boundaries of the patent. A skilled patent attorney can then assist his or her client in designing around the claims to avoid infringement. If a continuation is pending, there is no bright line scope of claim for which to design around. This delays competitors from being able to reliably design around the patent.
A third reason to file a continuation is to put the patent portfolio in a more attractive condition for licensing or sale. A potential licensee or purchaser will often be more interested in a patent family that includes at least one issued patent and at least one pending continuation. The issued patent demonstrates the underlying invention is patentable. The pending continuation enables the licensee of purchaser to take the patent claims the direction the licensee or purchaser wants to go. This is a sweet spot in patent monetization.
As mentioned above, the reason not to file a continuation is the cost. We generally charge about 4-5k to file the continuation and then you typically incur about 5-15k in the examination of the application. So it puts the total cost of the continuation at about 10-20k (compared to the typical 20k-30k for the parent application). We have clients that will take a single patent and then pursue several continuations over time. As you can see, this strategy can be valuable for the reasons described above, but can be costly as well.