Patents cannot be “renewed.” Once a patent has expired at the end of its patent term, the public is free to practice the teachings disclosed therein. Further, it should be noted that a Patentee is required to pay patent maintenance fees at specified intervals to keep a patent in force.
Failing to pay the requisite patent maintenance fee at each of the specified intervals results in the patent expiring prematurely. However, as a Patentee may file a petition to reinstate a patent which has expired for failing to pay a patent maintenance fee, a registered patent attorney should be contacted prior to taking any action (e.g., practicing the claimed invention of an expired patent).
It should be noted that in certain instances it may be possible to obtain patent protection for an improvement over an existing technology. To explore such a possibility, an Applicant should speak with a patent attorney.
To provide greater insight regarding why a patent cannot be renewed, one must consider what a patent actually represents. A patent is a property right which a national government grants to an Applicant for a limited period of time (e.g., generally 20 years from filing for a utility patent and 14 years from the grant date for a design patent). In exchange for receiving this limited property right, the Inventor agrees to describe the invention fully, in addition to detailing the “best mode” known at the time of filing (e.g., best ways to make, use, etc. an invention). Once this limited exclusionary period has expired, the public is free to practice the invention detailed in the patent without restriction.