CHAPTER V. OF WHAT RELATES TO THE TITLE IN OR UNDER LETTERS-PATENT. § 167. THE grant of letters-patent for an invention creates a legal estate of a peculiar nature, consisting of the exclusive right to make, vend, or use the subject of the grant for a specified period. It has many of the incidents of other legal estates, and among these are the equitable interests which may spring out of it either by contract or by operation of law. These various interests, legal and equitable, will now be considered. § 168. The person to whom the grant is made, by name called the patentee, is, of course, the holder of the legal title, which, like other legal estates, descends to representatives. But the patentee is not necessarily the inventor; for, whether an invention is or is not assignable at common law before any patent for it has been obtained, it has been deemed expedient to make it so assignable by statute. Accordingly provision has been made for the issuing of a patent to an assignee of the inventor, provided the application is made and the specification duly sworn to by the inventor himself, and the assignment is duly recorded.1 When so granted, the exclusive interest is vested as a legal estate in the assignee, who thus becomes the patentee of the invention, and the inventor himself is divested of the legal title. § 169. But although the assignee of an inventor, who has become such before the patent has issued, does not become the holder of the legal title to the patent until it has issued, he becomes the holder of a right to obtain the patent and to pursue certain remedies, both against his assignor and against third persons. Thus, where an inventor had made an application for a patent in his own name, which had been rejected, and a patent had been granted to a competing inventor, and after his rejection he had assigned his invention to the plaintiff, as set forth in his 1 Act of March 3, 1837, § 6; Act of March 3, 1839, § 7; Herbert v. Adams, 4 Mason, 15; Dixon v. Moyer, 4 Wash. 71, 72. specification on file in the Patent Office, and the plaintiff was authorized by the assignment to obtain the patent for himself, it was held that the plaintiff was entitled, even before recording his assignment, to pursue the remedy provided by statute for annulling the competing patent, given by the acts of July 4, 1836, § 16, and March 3, 1839, § 10.1 § 170. The statutes, however, which authorize the assignment of an invention before the patent has been obtained, appear to embrace only the cases of perfected or completed inventions. There can, properly speaking, be no assignment of an inchoate or incomplete invention, although a contract to convey a future invention may be valid, and may be enforced by a bill for a specific performance. But the legal title to an invention can pass to another only by a conveyance which operates upon the thing invented after it has become capable of being made the subject of an application for a patent. This is apparent from the provisions of the statute which require the specification and the application to be made in the name of the inventor. A contract to convey a future invention, or an improvement to be made upon a past invention, cannot alone authorize a patent to be taken by the party in whose favor such contract was intended to operate. § 171. With respect to the legal formalities to be observed in conveying inventions before an application for a patent, it is apparent that, as the statute authorizing this to be done prescribes no particular form of instrument, any instrument in writing which evinces an intention to vest the whole interest in the assignee, and to authorize him to take the patent in his own name, is a sufficient conveyance. Two requisites are however fixed by the act of March 3, 1837, § 6. These are, that the assignment shall be "first entered of record," and that the "application" shall be " duly made and the specification duly sworn to by the inventor." The first of these requisites, the registration, is of course to be regarded as speaking of the Patent Office as the place of registration, that being the place contemplated by all the statutes in pari materia. The time. relates to any time before the patent issues, although, for obvious reasons, the recording should be before or at the time of the appliGay v. Cornell, 1 Blatch. 506. 1 Nesmith v. Calvert, 1 Wood. & M. 34. cation. But, as we have seen, such an assignment, before a patent has been issued, may, it has been held, be made after the inventor has applied for a patent and been refused; that is to say, it may be made while proceedings to obtain the patent are pending in the name of the inventor; and if recorded at any time before the patent issues, the patent will rightfully issue to the assignee.1 § 172. Very nice questions may arise upon particular instruments, executed by inventors before an application for a patent, as to whether they do or do not amount to assignments of the legal title to the invention, or whether they are mere contracts or covenants to convey after the patent has been issued to the inventor. Thus, where an inventor, who had perfected a machine and was contemplating to make improvements thereon, and to take out letters-patent for the machine and the improvements, covenanted that he would assign the patents when obtained to the covenantees, and afterwards, in 1841, he obtained a patent for the machine, and in 1843 obtained a further patent for the improvements, a bill in equity was sustained to compel him to make the conveyances.2 In this case the instrument was manifestly a mere covenant for future conveyances, the parties not contemplating that the patents were not to issue to the inventor; and, although the defence was set up that the patent for the improvements obtained in 1843 was for a subject-matter not contemplated by the covenant, the instrument and the surrounding facts were not held to warrant that construction. But where any doubt arises on the true meaning and operation of such instruments, such doubts may be solved, in respect to the question whether they are to operate as assignments before the patent, or only as covenants to assign after the patent, by attending to the following considerations. That an inchoate right to obtain a patent on a perfected invention may be 1 Gay v. Cornell, ut supr. Nesmith v. Calvert, 1 Wood. & M. 34. I have endeavored to invent a phrase which, without circumlocution, shall sufficiently describe these assignments before a patent. But although in another branch of the law it is easy to speak of ante and post nuptial contracts, — and other similar phrases will occur to the reader, yet our language is not flexible enough, even with the aid of a Latin preposition, to describe these ante-patent assignments. I forbear, therefore, from attempting to introduce such an expression into my text, and leave my readers to use it, or to avoid it, as they best can, informing them at the same time that I do not make myself responsible for the correlative term of a post-patent assignment. Both are awkward enough. the subject of bargain and sale; but as the method of making such a sale available to vest the legal title in the invention as the subject of a patent in the purchaser has been regulated by statute, it is necessary to look into the instrument to see whether it contemplates that the patent shall issue to the supposed assignee or to the inventor. However absolute may be the words of bargain and sale of the invention, if the instrument contemplates that the patent shall issue to the inventor, it would seem that it must operate, as respects the legal title to the patent when obtained, as a contract to convey, and the party holding such an instrument will hold an equitable and not a legal title, until he has converted the former into the latter. If the instrument is executed and recorded before the patent issues, but it appears to have been intended that the patent shall issue to the inventor, and it does so issue, then I conceive that the holder of the instrument is the holder of an equitable and not a legal title. But if the instrument intends that the patent shall issue to the holder of the instrument, and it does so issue, the instrument is an assignment of the legal title under the act of 1837, as it is, if executed and recorded after the patent has issued to the inventor, under the act of 1836. § 173. There is, however, one class of instruments which, even if executed before the patent issues, will pass the legal title to the monopoly, although the patent itself happens to issue to the inventor; and these instruments, according to a decision of the Su 1 Clum v. Brewer, 2 Curtis Circ. C. R. 506. This was a case which arose upon an instrument executed by an inventor before a patent had been obtained, whereby he conveyed an undivided fourth part of his "invention," as described in his caveat then filed. But the instrument clearly contemplated the issuing of the patent to the inventor, and it was so issued. There was a covenant in the instrument for future conveyances. Now, although it was intimated in this case that the covenantee might possibly be regarded, after the patent had issued, as having a legal title to one undivided fourth part of the patent, yet as the case only called for the decision of the point that he had an equitable title, which clearly appeared, I think it proper to leave the position stated in the text as it stands. For, inasmuch as the statute regulating conveyances before a patent has issued contemplates an application by the patentee, and justifies an issue of the patent to another person only when such person records an instrument authorizing this to be done, I do not understand how a previous instrument can operate as a legal assignment of a patent which issues to the inventor, unless it appears to have been intended, by the terms of the conveyance, that the monopoly when obtained shall vest in the assignee. (See the note, infra.) preme Court of the United States, operate as assignments of the patent under the act of 1836. This will be the case where the invention is perfected and a specification prepared, and the assignment, being made and recorded in the Patent Office before the patent issues, requests that the patent may issue to the assignee, and otherwise evinces the intention of the assignor to make the assignee the owner of the legal estate or monopoly, when it has become perfect and absolute, even if the patent should issue in the name of the inventor. The effect of this decision is, that when parties undertake to act under the sixth section of the act of 1837, which directs the mode of procuring a patent in the name and for the benefit of an assignee, and the requisite steps have been taken for that purpose, but the patent, contrary to the intent of the conveyance, has issued to the inventor, the conveyance, being recorded before the patent issues, will operate as an assignment of the patent interest under the act of 1836, and a subsequent conveyance is not necessary to enable the assignee to sue in his own name. This decision was made apparently with a view to quiet titles, which had been taken and acted upon under the supposition that such was the law. It gives a somewhat broader operation to the act of 1836, § 11, than its terms appear to embrace; for whereas that act would seem to have contemplated only assignments after a patent has issued, the act of 1837 was passed to enable assignments to be made before the patent issues. But the construction is beneficial; and if the conditions stated by the court are observed, no injury can result from it.1 1 Gayler v. Wilder, 10 Howard, 477. The following is the reasoning of the court, as contained in the opinion pronounced by Taney, C. J.: "The first question arises upon the assignment of Fitzgerald to Enos Wilder. The assignment was made and recorded in the Patent Office before the patent issued. It afterwards issued to Fitzgerald. And the plaintiffs in error insist that this assignment did not convey to Wilder the legal right to the monopoly subsequently conferred by the patent, and that the plaintiff who claims under him cannot therefore maintain this action. "The inventor of a new and useful improvement certainly has no exclusive right to it until he obtains a patent. This right is created by the patent, and no suit can be maintained by the inventor against any one for using before the patent is issued. But the discoverer of a new and useful invention is vested by law with an inchoate right to its exclusive use, which he may perfect and make absolute by proceeding in the manner which the law requires. Fizgerald possessed this inchoate right at the time of the assignment. The discovery had been made, and the specification prepared to obtain a patent. And it appears by the language of |