Pennock v. Dialogue

27 U.S. 1 (1829)



The first inventor cannot acquire a good title to a patent; if he suffers the thing invented to go into public use, or to be publicly sold or use, before he makes application for a patent. His voluntary act or acquiescence in the public sale and use is an abandonment of his right; or rather creates a disability to comply with the terms and conditions on which alone the secretary of state is authorized to grant him a patent. 


Plaintiffs, Abraham Pennock and James Sellers, invented a way to improve the way hoses were made to make them tighter and resistant to air and water pressure, and had allowed the hoses to be manufactured and sold pursuant to an agreement with the manufacturer for seven years before obtaining a patent. Plaintiffs then sued defendant, Adam Dialogue, who did not have a contract with them, for patent infringement. The circuit court charged the jury that an inventor who allowed others to use his invention, with or without his consent, without claiming his rights as an inventor abandoned his inchoate right to exclusive use of the invention. The jury found for defendant, and the circuit court entered judgment for him.


Even if the plaintiffs had made their discovery public prior to obtaining a patent for the invention, do they still have the inchoate right to the exclusive use of the same? 




According to the Court, if an inventor makes his discovery public, looks on and permits others freely to use it, without objection or assertion of claim to the invention, of which the public might take notice, he thereby abandons the inchoate right to the exclusive use of the invention, to which a patent would have entitled him, had it been applied for before such use. The United States Supreme Court held that the Patent Act of February 21, 1793, required that an invention be unknown before the inventor applied for a patent. Since plaintiffs marketed their improved hoses before they applied for a patent, their invention was not unknown at the time of application and plaintiffs were not entitled to its exclusive use.

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