There are two main reasons why people file continuation patent applications:
- To pursue a second patent with broader patent protection for the invention than was obtained in the first patent; and
- To preserve their ability to direct claims in a future patent application to competitors’ products of which they become aware down the road, e.g., attempts to design around your existing patent claims.
If you feel the patent examiner was being too limiting with your original patent application and are interested in obtaining broader patent protection in a second patent, you may want to file a continuation application.
Reason 2 is based on the procedural requirement that patent applications be “copending” to claim priority back to the filing date of your original patent application. Copending means that you file a second patent application before the first patent application goes abandoned or issues as a patent. There can be a chain of copending patent applications, .e.g., application 4 is filed before application 3 expires or issues; application 3 was filed before application 2 expires or issues, etc.
Companies who want the flexibility to craft claims directed to their competitors products will often file continuation applications primarily to keep a chain of copending patent applications alive. If the chain of copending applications ends, it is generally not possible to pursue a patent with claims targeting a competitor’s product thereafter.