The opinion of the court was delivered by: GALSTON
This is a suit in equity brought pursuant to section 4918 of the Revised Statutes (U.S.C., title 35, § 66 [35 U.S.C.A. § 66]).
Plaintiff is the inventor and patentee of letters patent No. 1,880,174, for an improvement in continuous aim gunfire control system, issued September 27, 1932, on an application filed May 25, 1932. Defendant is the patentee of letters patent No. 1,937,336, granted on the application of Hannibal C. Ford and Elliott P. Ross, for an improvement in fire control system, filed December 10, 1927. It is alleged that these are interfering patents; that the defendant's patent purports to be founded upon the mathematical concept disclosed in plaintiff's patent; that the claim of the defendant's patent read fully and squarely on the invention disclosed and claimed in the plaintiff's patent and that the disclosure in the defendant's patent is insufficient to enable any person skilled in the art to make and use the patented invention. Accordingly the plaintiff seeks a decree adjudging that he is the first and original inventor of the invention set forth in his letters patent; that the two patents are interfering patents and that the defendant's patent be declared invalid.
The answer alleges that no claims of the respective parties are in fact interfering claims and avers that no cause of action under section 4918 of the Revised Statutes exists.
Both inventions have in general the same object. The subject-matter is a fire control system adapted for use on unstable platforms such as the deck of battleships, to eliminate the effect of roll and pitch of the platform on the train and elevation settings of the gun mounted on such platform.
Dugan states the object of his invention is "to provide such guns with control mechansim for maintaining the guns continuously corrected in train and elevation for the 'trunnion tilt' error caused by rolling and pitching of the platform, regardless of the position or movements of the target in space relative to the gun."
Ford and Ross state a further object of their invention is "to provide in connection with and in part operable from the director an instrument for introducing the desired angular displacements of a gun from the line of sight of the director, commonly known as sight depression and sight deflection, and for calculating the ever changing train and elevation necessary to be applied to the gun in order that its aim may be preserved in spite of the angular motion of the craft."
At the outset of the trial plaintiff restricted his allegations of interference to claims 1 and 2 of each patent respectively, but the proofs and argument limit the issue to claims 1 of each patent.
U.S.C., Title 35, § 66 (33 U.S.C.A. § 66), provides: "Whenever there are interfering patents, any person interested in any one of them, or in the working of the invention claimed under either of them, may have relief against the interfering patentee, and all parties interested under him, by suit in equity against the owners of the interfering patent; and the court, on notice to adverse parties, and other due proceedings had according to the course of equity, may adjudge and declare either of the patents void in whole or in part, or inoperative, or invalid in any particular part of the United States, according to the interest of the parties in the patent or the invention patented. But no such judgment or adjudication shall affect the right of any person except the parties to the suit and those deriving title under them subsequent to the rendition of such judgment. (R.S. § 4918.)"
As a prerequisite to declaring claims of a patent void as interfering with claims of a prior patent, substantial identity between the claims must be found, as interpreted in the light of the text, specifications, drawings and prior art. International Signal Co. v. Vreeland Apparatus Co. (C.C.A.) 278 F. 468; Petersen v. General Seafoods Corporation (C.C.A.) 66 F.2d 459.
Dugan, in March, 1930, brought action in the United States Court of Claims against the United States government because of use by the government of a gun manufactured by the defendants herein, which he alleged infringed an earlier patent granted to him on October 29, 1929. The apparatus was known as "Mark XIX." Prior thereto an interference had been declared in the Patent Office on September 27, 1928, between the then copending application for the defendant's patent in suit and an earlier Dugan patent. The seventeen counts involved in the interference were dismissed on the ground that the counts were not patentable to Dugan, and count 17 was disclaimed by Dugan and priority awarded to Ford and Ross. In that interference proceeding Dugan became acquainted with the Ford and Ross invention.
Claim 1 of plaintiff's patent No. 1,880,174, reads as follows: "An unstable platform, a sight, means for mounting said sight to pivot universally on said platform, a gun rotatable about train and elevation axes on said platform, means for simultaneously determining the pitch of the platform in the vertical plane of sight to the target and the roll of the platform in a plane perpendicular to said plane of sight and perpendicular to said platform at all angles of pitch, means for introducing displacements of the gun from the said vertical plane of sight and from a horizontal reference plane, and mechanism operable by both of said means for calculating and applying to the gun all of the necessary corrections in train and elevation to preserve its aim on the target throughout the roll and pitch of the platform."
Claim 1 of defendant's patent No. 1,937,336, reads as follows: "In a fire control system for ordinance mounted on an unstable platform, the combination of a director, means for eliminating the effect on the line of sight of the director of angular movements of the platform in the vertical plane of the line of sight and in a vertical plane at right angles thereto, whereby the operation of following a target in train and elevation may be performed as if the director were mounted upon a stable platform, means for introducing angular displacements of a gun from the line of sight, and means operable by both said means for calculating and applying to the gun the train and elevation necessary to preserve its aim in spite of the angular movements of the platform."
Dugan's position is that the claims are substantially the same in scope, and that they differ only in words. He finds an unstable platform positively included in his own patent and inferentially in the defendant's claim. The next element is a sight to pivot universally on the unstable platform. Defendant's claim, said Dugan, calls for a "director" instead of a sight, and the reference numeral "1" in Fig. 1 of the drawing, he contends, ...