Submarine Applications

In the bad old days (or good old days depending on one's perspective), it was possible to secure patent protection far beyond the ordinary life of a patent. The trick was to prosecute an application to allowance, and then file a divisional application just before the patent issued. The first divisional could then be prosecuted to allowance, and then a second divisional filed before the first divisional issued. This could be done and over again, each time gaining a new 17 year term from the date of issuance. Just to show how ridiculous the system became, a patent issued in 2000 on an application filed in 1936 !

Congress tried to put a stop to these so-called submarine patents by requiring applicants to file a terminal disclaimer on these divisionals pending after an earlier member of the patent family had already issued as a patent, disclaiming any term beyond the term of the earlier patent. But there were still abuses to the system because the terminal disclaimer rule only applied to a pending application where the claims were obvious over the claims of the earlier issued patent. If the applicant chose to serially claim protection on different aspects of the invention, then the terminal disclaimer restriction would not apply. Some have said that the result was grossly unfair to society, and a terrible abuse of the patent system. The Lemelson patents on the product bar codes are a case in point. The original application was filed in the 1950s, and yet many of the Lemelson patents are still in force. Fortunately, the Courts are starting to invalidate those late-filed patents due to prosecution laches .

In 1995 a new law took place, limiting the term of a patent to 20 years from the earliest claimed U.S. priority date. If that law had been in effect at the time of the Lemelson patent prosecution, the resulting patents would have expired in the 1970s at the latest. This is a very good change in the law, and advantageously also places the U.S. in accord with the patent laws of all the other countries on the planet.

One would have thought the U.S. had said goodbye to submarine patents in 1995. But no. One should never underestimate the cleverness of the patent bar. It is still possible to have a submarine patent of sorts, by filing a patent application with extremely narrow, irrelevant claims, waiting until the application publishes 18 months later, and afterwards amending the claims to cover much more significant subject matter. By that ruse the competition falsely thinks it is free to practice embodiments outside the narrow scope of the published claims, and acts accordingly.

It is also possible to file a narrow application claiming a first embodiment that is not terribly useful, and then file subsequent applications disclosing and claiming more useful variations. As long as the applicant disclosed the best mode of the invention that was claimed in the earlier application, the subsequent applications are appropriate because the best mode of those applications only need to be disclosed upon filing of those subsequent applications. The applicant can continue to secure additional subject matter by filing terminal disclaimers, but competitors cannot do so because they have overlap of inventors or ownership with the original application.

This is the classical one-two punch. The applicant forces the competitors to alter their products to circumvent an original set of claims, and then sues them under the subsequent sets of claims for producing and selling the altered products.