Memo: A Note on Pennock v. Dialogue | jdickins | July 23, 2012


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Memo: A Note on Pennock v. Dialogue

Justice Story’s opinion in this case is obscure and difficult to parse; but it raises so many of the critical issues regarding patents and patent protection that it is worth struggling through to try to understand exactly what he was getting at. The facts are pretty simple: Pennock and Sellers, the plaintiffs, (Pennock and Sellers are also the “plaintiffs-in-error” – i.e., the parties who lost in the court below and have brought the case to the Supreme Court; in modern terminology, they are the “Petitioners,” and Dialogue is the “Respondent.”) have a patent on a new kind of fire hose. The invention was completed in 1811. Shortly thereafter, they entered into a license agreement under which Samuel Jenkins made and sold the hose invented by the plaintiffs; between 1811 and 1818 over thirteen thousand feet of hose, constructed according to the invention of the patentees, had been made and sold in Philadelphia. The “letters patent” were applied for and obtained in 1818. Plaintiffs sued Dialogue, the defendant, for patent infringement; we can assume that Dialogue was manufacturing and selling hose that was identical, in all relevant aspects, to hose for which plaintiffs held the patent. The defendant asserted that the patent was invalid because of Jenkins’ sale/use prior to 1818. The 1793 Patent Act, in effect at the time, had several provisions relevant to the issue. Justice Story describes them as follows:
The first section provides, "that when any person or persons, being a citizen or citizens of the United States, shall allege that he or they have invented any new or useful art, machine, manufacture, or composition of matter, or any new or useful improvement on any art, machine, or composition of matter, not known or used before the application; and shall present a petition to the Secretary of State, signifying a desire of obtaining an exclusive property in the same, and praying that a patent may be granted therefore; it shall and may be lawful for the said secretary of state, to cause letters patent to be made out in the name of the United States . . . reciting the allegations and suggestions of the said petition, and giving a short description of the said invention or discovery, and thereupon, granting to the said petitioner, &c. for a term not exceeding fourteen years, the full and exclusive right and liberty of making, constructing, using, and vending to others to be used, the said invention or discovery, &c." The third section provides, "that every inventor, before he can receive a patent, shall swear, or affirm, that he does verily believe that he is the true inventor or discoverer of the art, machine, or improvement for which he solicits a patent." The sixth section provides that the defendant shall be permitted to give in defense, to any action brought against him for an infringement of the patent, among other things, "that the thing thus secured by patent was not originally discovered by the patentee, but had been in use, or had been described in some public work, anterior to the supposed discovery of the patentee."
[Emphases added] These are, Story writes, “the only material clauses bearing upon the question now before the court; and upon the construction of them, there has been no inconsiderable diversity of opinion entertained among the profession, in cases heretofore litigated. . . .” The trial court issued the following charge to the jury as follows:
"We are clearly of opinion that 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 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. And we think it makes no difference in the principle, that the article so publicly used, and afterwards patented, was made by a particular individual, who did so by the private permission of the inventor. As long as an inventor keeps to himself the subject of his discovery, the public cannot be injured: and even if it be made public, but accompanied by an assertion of the inventor's claim to the discovery, those who should make or use the subject of the invention would at least be put upon their guard. But if the public, with the knowledge and the tacit consent of the inventor, is permitted to use the invention without opposition, it is a fraud upon the public afterwards to take out a patent. It is possible that the inventor may not have intended to give the benefit of his discovery to the public; and may have supposed that by giving permission to a particular individual to construct for others the thing patented, he could not be presumed to have done so. But it is not a question of intention, which is involved in the principle which we have laid down; but of legal inference, resulting from the conduct of the inventor, and affecting the interests of the public. It is for the jury to say, whether the evidence brings this case within the principle which has been stated. If it does, the court is of opinion that the plaintiffs are not entitled to a verdict." [emphasis added]
The “single question then is,” Justice Story writes, “whether the charge of the court was correct in point of law.” I.e., was the trial court’s formulation of the legal principle(s) applicable to the question of the validity of plaintiffs’ patent correct?

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June 14, 2013

Professor David Post


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