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CASES DECIDED

IN

THE COURT OF CLAIMS

November 14, 1932 (in part), to January 9, 1933

WILLARD S. ISHAM, EXECUTOR OF THE ESTATE OF CLARA H. ISHAM, v. THE UNITED STATES

(No. 33966.

Decided March 7, 1932. Motion for new trial over

ruled June 5, 1933]

On the Proofs

Patents; infringement; validity; fuses for emplosive projectiles.

(1) Claims 1, 2, and 5–10, inclusive, of the Isham patent on a firing device or fuse for explosive projectiles, U.S. Letters Patent No. 1179105, held invalid for want of novelty. Claims 14 and 21 thereof held not infringed by the defendant.

(2) Claims 4, 5, 19–25, inclusive, 31-34, inclusive, 44, 45, 47, and 48, of the Isham patent on fuse for explosive projectiles, Letters Patent No. 1237909, held not infringed.

(3) Claim 8 of the Isham patent on fuse for explosive projectiles, Letters Patent No. 1188178, held void for want of

proper description. Same; accidental infringement.-Where the alleged infringing appa

ratus functions in part as does the invention claimed to be infringed, but only in an accidental way, not desired, it does not

amount to infringement for which damages are recoverable. Same; concealment of details of apparatus; presumptive evidence of

infringement.-Where in an action for infringement of letters patent the Government refuses to divulge the details of its own apparatus, and to show lack of identity with the patented device, there is a strong presumption of identity, and the way is opened for the introduction of secondary evidence as to its

character. Same; requirements of description; specifications.—The descriptive

portion of a patent must be sufficiently complete and comprehensive to enable those skilled in the art to readily practice the same, and the specifications must be clear enough to enable the public to know the scope of the monopoly.

1

Reporter's Statement of the Case The Reporter's statement of the case:

Mr. Clarence 0. McKay for the plaintiff. Steward & McKay were on the briefs.

Mr. Charles F. Kincheloe, with whom was Mr. Assistant Attorney General Charles B. Rugg, for the defendant.

The court made special findings of fact, as follows:

I. The plaintiff, Willard S. Isham, is a loyal citizen of the United States, a resident of the District of Columbia, and executor of the last will and testament of Clara H. Isham deceased, who was the original plaintiff herein; she was also a loyal citizen of the United States and a resident of the District of Columbia, and died on or about the 21st day of April 1925.

Said Willard S. Isham was graduated in 1882 at the University of Vermont as an engineer, and for a long period of time was engaged in the building and construction of railroads and buildings in Mexico and the United States, which required the use of enormous quantities of high explosives, with which he became familiar. Early in life he became a student of ordnance and munitions and for many years devoted his energies to this subject, pursuing his studies therein in the United States and Europe.

II. Explosives as used in ordnance are broadly classifiable into sensitive explosives and insensitive explosives. Sensitive explosives are those of such a nature as will explode upon a blow or shock such as that produced by a hammer on an anvil. Examples of this class are explosive gelatin or dynamite, dry guncotton or guncotton carrying a small percentage of water, and uncompressed fulminate of mercury. Examples of insensitive explosives are ordinary black gunpowder and trinitrotoluol, ordinarily referred to as TNT. By alterations in the consistency of explosives, the one class of explosive may merge into the other and a sensitive explosive may, therefore, be made more or less insensitive. Such merging is exemplified by guncotton which is very sensitive to blows in its dry state but which becomes less sensitive upon the addition of water. When the percentage of water reaches thirty-five percent guncotton becomes in

Reporter's Statement of the Case sensitive to blows. The sensitiveness of explosive gelatin decreases upon the addition of camphor and when such addition reaches ten percent the gelatin becomes an insensitive explosive. Fulminate of mercury approaches the insensitive state when compressed. When used in its fully compressed state it is an insensitive explosive.

III. A shell when fired from a gun has a certain definite total amount of kinetic energy imparted to it during its progress through the gun barrel by the explosive combustion of the propelling charge.

While in motion toward the target it loses a portion of this imparted energy through air resistance and arrives at the target with less total kinetic energy than when it left the gun.

The pressure shock received by the shell and its contents, due to its inertia in starting from a state of rest, is dependent upon and includes such items as the rate of combustion in the propelling charge, the amount of propelling charge used with reference to a given weight of shell, and the length of the barrel of the propelling gun which determines the time interval in which the propelling gases act on the shell to accelerate it.

The impact shock received by a shell when it hits a target includes such factors as its time rate of deceleration (the rate at which a moving shell assumes a state of rest), weight of the shell, its velocity at the time it hits the target, the stopping qualities of the target (dependent upon whether the target is of thick steel, thin steel, wood, or water), and the character of the hit (whether direct or glancing).

A shell making a direct hit on the heavy steel plate at a normal range will undergo a greater pressure shock than that which it receives when it is fired from the gun.

IV. In 1899 Isham conceived the idea of utilizing an explosive in a shell or projectile, the shell being so designed and the explosive having such a degree of sensitiveness that the shock or impact upon the shell due to expulsion from the gun was not sufficient to explode the material therein but the shock or impact of the shell against the target would be sufficient to set off the main bursting charge of the shell.

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Reporter's Statement of the Case Isham designed a shell with a front chamber formed by the shell walls adjacent the point of the shell and an inner partition or diaphragm before separating the wall between that chamber and the rear cavity of the shell, and employing a camphorated explosive gelatin in the front chamber to set off the main bursting charge of the shell. Some shells of this design were made and certain experimental gunfiring and target impact tests of them were carried out by the War Department during the period from 1899 to 1903 with the front chamber of the shell charged with explosive gelatin containing four percent camphor. Some of these shells were fired successfully from a gun and burst upon impact with the target. One shell exploded prematurely in the gun

from which it was fired. V. The experimental work during the period from 1899 to 1903, referred to in Finding IV, ultimately led to the conception by Isham of a fuse or firing device for explosive projectiles.

In 1906 Isham talked with Captain William S. Sims (later Admiral Sims) about this fuse.

There is no satisfactory evidence to indicate whether Isham at that time disclosed the constructional details of his fuse.

VI. On May 12, 1914, the said Willard S. Isham filed in the United States Patent Office an application for letters patent for a “ Firing device or fuse for explosive projectiles”, upon which application there were granted to him United States Letters Patent No. 1179105, dated April 11, 1916, a copy of which is by reference made a part of this finding. The proceedings in the Patent Office on said application are shown by the file wrapper and contents in said application, a copy of which is by reference made a part of this finding.

VII. Subsequent to the filing of the above-mentioned patent application, Isham took up the discussion of his fuses with the Navy Department and a certain board, known generally as the Fiske Board, was organized by order of the Secretary of the Navy on October 2, 1914, with Rear Admiral Bradley A. Fiske as senior member or chairman, to

Reporter's Statement of the Case

investigate and report upon the value of the Isham shell and fuse for naval purposes. The Board's work began on or about October 5, 1914, and was discontinued in the early part of 1916.

VIII. At one of the early meetings of the Fiske Board in October 1914, Isham presented to that Board copies of the drawings and descriptive part of the specification of his application for the patent no. 1179105 in suit, withholding the claims, which application had been filed in the Patent Office the preceding May, and drawings of his diving shell substantially as shown in his patent no. 1188178 in suit, the application for which patent was filed shortly thereafter, November 18, 1914, and explained to the Board the structural and operating features of this shell and fuse and his previous experimental work in 1899–1903 in the safe use in his diaphragm shells without a safety chamber of such sensitive explosives as he proposed to use in the fuse to be tested by the Board. At this time Isham suggested the use of fulminate of mercury as well as explosive gelatin as the relatively sensitive detonator charge.

IX. In gunfiring and target impact tests conducted before the Fiske Board of the diving shell and fuse of the Isham patents nos. 1188178 and 1179105, in suit, the Board refused to permit the employment of camphorated explosive gelatin or any other relatively sensitive explosive mentioned in the patent no. 1179105, as the semi-insensitive charge of the fuse because of the absence of a safety chamber containing that charge. A black powder charge incapable of performing the function ascribed in that patent to the semi-insensitive charge, i. e., exploding the bursting charge of the shell instantly upon target impacts of sufficient intensity to seriously deform the shell, was used in the fuse instead. Black powder was also used as the shell charge.

The black powder charge was used in the shell and fuse merely for the purpose of determining the diving and underwater-run capabilities of the Isham cup-nosed shell in which the fuse was employed and the percussion operation of the fuse by impingement of the firing pin with the primer cap of the fuse upon the impact of the shell with water and the

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