# McClurg v. Kingsland

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United States Supreme Court
42 U.S. 202
McClurg v. Kingsland
THIS case was brought up by writ of error from the Circuit Court of the United States for the western district of Pennsylvania.
The facts are sufficiently stated in the opinion of the court.
The bill of exceptions which was taken on the trial below was as follows:
And the plaintiff thereupon excepted to certain parts of the instructions so given by the court to the jury, which instructions so excepted to are hereinafter set forth, to wit:
'It has, however, been urged by the plaintiff's counsel that the right to the continued use is restricted to the 'specific machine, manufacture, or composition of matter so made or purchased,' so that a defendant is protected no farther than in the case of the invention (for which this patent was granted) prior to the application, and is liable to damages if he makes any rolls by Harley's plan afterwards.
'We, therefore, feel bound to take the words, 'newly invented machine,' in the act of 1839, manufacture, or composition of matter and such invention, to mean the invention patented, and the words 'specific machine,' to refer to the thing originally invented, whereof the exclusive right is procured by patent, but not to any newly discovered improvement to an existing patent.
'The use of the patent must be of the same specific improvement originally invented, as was before the application used by any person who had purchased or constructed the machinery on which he operated to produce the effect described in the specification; but when such person confines the future case to the specific mode, method, manner, and process of producing the described effect, it is by the words and true meaning of the law, without liability to the inventor or other person interested in the invention, so construed; and by thus protecting the person who has engaged the use of an invention before the application for a patent, the great object of the patent laws, as declared in the 4th section of the act of 1837, will be consummated; that is, to protect the rights of the public and 'of patentees in patented inventions and improvements.' 4 Story, 2547. A different construction would make it necessary to carry into all the former laws the same literal exposition of the various terms used to express the same thing, and thereby changing the law according to every change of phraseology, make it a labyrinth of inextricable confusion.
'Our opinion, therefore, is, that the defendants have a right to the continued use of the improvement patented to Harley; the facts of the case, which are not controverted, have equal effect with a license, and the evidence brings the defendant under the protection of the act of 1839, by the unmolested notorious use of the invention before the application for a patent. Nothing has been shown on the part of the plaintiffs to counteract the effect of this prior use; as assignees of Harley, they stand in his place as to right and responsibility; they took the patent, subject to the legal consequences of his previous acts, and connecting these with the want of an assertion of a right, to the use by the defendants of the invention patented, till this suit was brought in September, 1835, protects them from liability.
'In our opinion, your verdict ought to be for the defendants. Verdict accordingly, and judgment for defendants.'
Dunlap, on behalf of the plaintiffs in error, contended that the court below had erred in charging the jury.
1. That the facts justified the presumption of a license or grant to use the invention, and that defendants were protected thereby, independent of any act of Congress.
2. That the words, 'specific machine,' in the 4th section of the act of 1839, referred to the invention itself, and that the authority to use it before the patent carried the right to continue to make and use it after the patent had issued.
Mr. Justice BALDWIN delivered the opinion of the court.

## Notes

This work is in the public domain in the United States because it is a work of the United States federal government (see 17 U.S.C. 105).
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