Under U.S. patent laws, a patent application must be filed within one year of first publicly using the invention, offering the invention for sale or distributing a printed publication. The following case illustrates an example of a device that was not used in public view but still considered to be a public use.
In New Railhead Manufacturing, LLC v. Vermeer Mfg. Co., 298 F.3d 1290 (Fed. Cir. 2002), the invention was related to a drill bit for drilling rock formations and a method for drilling rock formations. The drill bit was actually used underground, out of plain sight of others. Nonetheless, the Court explained that the phrase “public use” under U.S. patent laws does not mean open and visible in the ordinary sense. The meaning of “public use” does not hinge on whether the device was seen by others. “Public use” includes “any use of the claimed invention by a person other than the inventor who is under no limitation, restriction, or obligation of secrecy to the inventor”. Hence, the use of the drill bit was “public use”.
Testing and experimentation of the invention could negate the use of the device as a “public use” for the purposes of determining when the “one year” time period begins. However, such testing and experimentation must cease at the time the inventor realizes that the invention works for its intended purpose. Otherwise, continued use may constitute “public use” which would bar the inventor from seeking patent protection after the “one year” time period. In New Railhead, the inventor made a second prototype which contained some improvements to the first prototype. Unfortunately, the record did not indicate that there was an issue as to the efficacy of the drill bit. Hence, the use of the first drill bit prototype was not considered to be an experimental use.
U.S. Patent Law provides a limited time period (i.e., one year) in which inventors can market and sell their invention for various reasons without filing a patent application. However, it is typically beneficial to file as early as possible. Also, if interested in seeking patent protection in foreign countries, a patent application should be filed prior to any type of public disclosure, offer for sale or distribution of any printed material to the public in order to preserve the maximum rights.
You may also be interested in reading Preventing Loss of Patent Rights.
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