The Hidden Risk of Keeping a Patent Application Alive Too Long – Prosecution Laches. EP181

In this episode of The Patenting for Inventors Podcast, I explain prosecution laches, a rarely used but important doctrine that can create problems when a patent applicant keeps an application pending for an extraordinarily long time. I discuss when lengthy prosecution can become unreasonable or unfair, particularly when competitors have invested in products or industries while no enforceable patent existed, and why simply filing continuations or having a long prosecution history does not automatically create a problem. I also cover the historical "submarine patent" issue, the significance of very lengthy delays, and the recent Gilbert Hyatt litigation, including the Supreme Court's 2026 decision not to hear the case. Finally, I explain how inventors can legitimately use continuations while avoiding a prosecution history that looks like an attempt to wait for an industry to develop and then shape patent claims around successful competitors.