Joseph McKenna

“ We are told by the findings of the court of claims that a gas check 'is subject to a pressure of from 30,000 to 40,000 pounds per square inch, to very high temperatures, to the effects of corrosive gases, and the effects of rapid and violent shocks.'
We need not, however, dwell longer on the excellence of the invention. The government has testified to its excellence by using it in the guns intended for the national defense.
But it is contended that the claim of the patent is for a specific combination of elements, and that that combination of elements is not used by the government. ”

“ Describing his invention, De Bange calls it 'certain new and useful improvements in breech-loading guns.' Specifying the improvements, he says that they 'apply to breach-loading guns which employ a screw plug having its threads interrupted.' Further specifying, he adds: 'I have devised a system of packing placed in advance of the plug, and which is expanded by the force of the explosion of the powder to make a tight joint to prevent the leakage age of gas.' He declares the drawings form a part of the specification, and represent what he considers the best means of carrying out the invention. ”

“ The government contends that it has not infringed the De Bange patent. Infringement is a question of fact, and as an aid to its solution courts are furnished usually with an expert comparison of the contending devices, their identity or difference of construction and modes of operation. This record is destitute of such testimony. The government contends for the very narrow construction of the patent based on its claims and the prior art. ”

“ If our purpose was speculative, not practical, we might pause to wonder how such substances could produce such results under the conditions to which they are subjected, and by wondering we express in a way the quality of the invention. ”

“ The fact that practically the same gas check is in use in all United States Army guns of recent construction, and is being applied to guns now being made by the Bethlehem Iron Company, under contract with the War Department, should also be considered, since independent action on the part of the Navy Department might easily be against the interests of the government. ”

“ The findings lack, and, it may be, necessarily lack, definiteness. They trace the history and progress of the invention of gas checks from an early period to the culmination in the patent to Colonel De Bange, an officer of the French army, in 1884, granted upon an application made in 1883. ”

“ The only explanation of them is in the argument of counsel and an exhibition of the patents. It is very doubtful if we may take notice of even the American patents; more doubtful if we may of the foreign ones. ”

“ There was a difference between it and Berdan's device, but the officers of the government doubted if the difference was material, and concluded that it was a matter for the courts to decide. It is true there was no assertion of right against the Berdan device in consequence of the difference between it and the device used by the government as, it may be said, there was in the case at bar by the letter of Admiral Ramsey of September 3, 1891. ”

“ Respectfully returned to the honorable Secretary of the Navy.
The bureau has not manufactured and is not using any gun carriages which contain principles which could be held as infringing any claims secured in United States patent No. 331,618. The gas check which has been adopted for the naval guns of 6-in. caliber and upwards resembles in certain features that described in United States patent No. 301,220, issued to Col. De Bange. It also differs from it materially in particulars which are original in this bureau. ”

“ U.S. Navy, Chief of Bureau of Navigation,
Navy Department, Washington.
In 1884 the ordnance officers of the United Stated, after experimenting with the De Bange device, adopted it for heavy ordnance (5-inch caliber and upward) , and have used no other device since.
'The United States government [we quote from thr findings] has never disputed the title of claimant's assignor, Colonel De Bange, as inventor of the said invention ”

“ The entire packing thus made is adapted to maintain its form, but to allow a small amount of radial expansion sufficient to pack the joint tightly against the escape of gas. This expansion is due to two causes,-the tapering form of the front end of the pin N, which acts on the interior of the packing, and the powerful compression received from the head N'. ”

“ They are described in the patent as follows: 'Figure 1 is a central longitudinal section. The strong lines show the parts ready for firing. The dotted lines show the transverse lever in a position for conveniently operating to turn the screw plug. Fig. 2 is a rear view showing the parts locked. Fig. 3 is a corresponding view showing the parts unlocked. . . . Figs. 6 and 7 represent the packing ring detached. Fig. 6 is a face view, and Fig. ”