QUESTION: If a patent is no longer active due to failure to pay maintenance fees in 2011, may another person re-file as their own? Want to file patent and see there was one by someone else originally granted in 2003, but is no longer active as failure to pay maintenance fees in 2011. May I file a similar patent as my own today?
ANSWER: Probably, no.
In order to keep an issued utility patent "alive", maintenance fees must be paid to the patent office. Maintenance fees are not required for design patents.
The maintenance fees are due 3 years, 7 years and 11 years after the patent issues. If the fees are not timely paid, the patent will lapse and no longer be in existence.
If a patent expires due to non-payment of a maintenance fee, others are free to use the invention.
However, an expired patent does not give one the right to file a patent application that is identical to the expired patent.
To file a patent application, one must be the inventor of the invention. If one just copied the expired patent, one would not be the inventor.
Also, a patent application must describe a new invention - something that has not previously existed. If the patent application was identical to the expired patent, there would not be a new invention.