Can an Inventor Sell or Publicly Use an Invention Before Filing a Patent Application?

Short Answer

Possibly for up to one year, but it’s not a great idea.

Fact Pattern

Our inventor has a great new device. The inventor is thinking about patent protection, but it’s expensive to apply. In addition, the inventor isn’t totally sure what others will think of the idea. Bursting with curiosity, the inventor will be tempted to give a few devices away. If market interest is there, the inventor may then want to sell a few devices to help pay for the cost of the patent application.

Statutory Rule

Under U.S. statutory law (35 U.S.C. 102), sale of the invention or public use of the invention more than one year before filing the patent application is an absolute bar to patentability. The United States Patent and Trademark Office will not allow a patent application to issue if the invention was sold or used publicly before the one-year date. There may be an argument for experimental use, but this route is highly risky and beyond the scope of this blog post.

Case Law

Consider Lough v. Brunswick decided by the Federal Circuit in 1996. Lough was a repairman for a boat dealership in Florida. He noticed that an upper seal assembly of a Stern drive for inboard/outboard motors failed often due to corrosion. On his own time, he used his metal lathe to create a new upper seal assembly that was corrosion resistant. Corrosion resistance takes a long time to observe. Therefore, he gave several prototypes away to friends.

The court reasoned that 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. The court held that Lough publicly used the seal assemblies by providing them to friends, because the friends were not under a limitation, restriction, or obligation of secrecy. Furthermore, the Court held Lough’s patent invalid, because his public use was more than one year before filing. Lough missed out on $1.5 million.


Based on Lough’s example, our hypothetical inventor does not want to lose his patent rights. Therefore, he should make sure to file the patent application before one year passes after sale or public use of the invention. However, the inventor should ideally file before public use or sale itself. This helps eliminate ambiguity and can remove an issue before the court. Furthermore, some foreign countries have “absolute novelty” requirements that completely bar a patent for any public use or prior sales. Therefore, if the inventor may want foreign protection in an absolute novelty country later, best practice is to file the patent application before public use or sale.

If you need help with your patents, trademarks, copyright, or trade secrets, please contact us.

Jeremy I. Maynard
Registered U.S. Patent Attorney
Troutman & Napier, PLLC
4740 Firebrook Blvd.
Lexington, KY 40513
Tel: 859-253-0991
Web: Troutman & Napier, PLLC
Originally Published at: Maynard.Law
Originally Published by: Maynard.Law

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