Opinion of the Court

By this method of draw-rope construction Carley accomplished the novel idea of encircling the buoyant body in such a way as to secure a tight, immovable, nonshifting ring of rope, sufficiently slack at the desired point to accommodate the reverse movement vital to free passage of the bottom of the float through the orifice of the buoyant body. Proper alignments were maintained, and the ropes employed were made to function both as to their tensile strength in bearing a load and giving needed pressure to maintain stability. The patent was a success. The Government used it, and to within a very few months of the expiration of the patent its validity had never been challenged by either the Government or anyone else.

In what respect does the device made for and used by the Government differ from the Carley patent in suit? This we think appears from defendant's exhibit reproduced herewith.

The difference in structure upon which the defendant reies as determinative is the absence of the draw ropes p and p1 from the float made by the Athens Company for the Government, and in their place the zigzag or shoe-lace arrangement of the draw ropes. The defendant contends that the zigzag construction attains the result by a "lacing action," a crisscross pull similar to shoe laces, and the Carley patent depends upon a "draw-string action." The refinement is extremely technical. To sustain the defense emphasis is put upon the word "longitudinally" in Carley's claims "draw ropes extending longitudinally along the upper and lower sides of the buoyant body," the defense insisting that the zigzag draw ropes in the Athens model do not extend longitudinally but crisscross fashion. Plaintiff in reply pertinently observes that Carley's claims do not use the words "in an undeviating line longitudinally," and what is more Carley's device was made in the shops of the plaintiff by employing the zigzag draw-rope construction and marketed with the same disclosed long before the Athens Company did the same thing. It was in no sense unusual. Defendant does not dispute the identity of results. Beyond disputation is the fact that the Athens type of float reaches the same end by utiliz

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Opinion of the Court

ing the same elements in a slightly different way. Carley recognized the prime necessity for rope rings so constructed as to permit a degree of slack on the inside of the float and high pressure on the outside if he was to attain the desired reversibility of the bottom. This essential feature of the device was likewise important to the Athens corporation. It characterizes the invention; it is indispensable to efficient operation. May it then be said that by the adoption of a mere change in form wthout a substantal change in result, or functioning of the elements of a prior patent, a user may escape infringement? One skilled in the art could, without doubt, have obtained from a mere physical inspection of Carley's life float the idea embodied in the Athens float. Seemingly it required no originality to do what the Athens corporation did in constructing its float. At least no patent was applied for. In Graham v. Mason, 5 Fish. 11, affirmed by the Supreme Court in Mason v. Graham, 23 Wall. 273, the Supreme Court said:

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Infringement depends not so much upon the form of the particular device in question or upon the name given to it in the specification as upon the functions it performs, and it is well-settled law that if one device is employed in a similar combination as another and performs the same function in the same way, the two are substantially the same, although they may be different in form and may be known among mechanics by different names."

We can not escape the conclusion that what was done in the Athens factory was the equivalent of the Carley patent. The case of Central Foundry Co. v. Coughlin, 141 Fed. 91, 94, illustrates the fact. In this case the court said:

"An equivalent is defined as a thing which performs the same function, and performs that function in substantially the same manner, as the thing of which it is alleged to be an equivalent."

In our view of the case, to take away from Carley the fruits of an invention never heretofore challenged, although used by the Government and others, well known in the art, useful and valuable, upon the narrow and extremely technical contentions interposed herein would be extending the patent laws beyond their legal scope.

Opinion of the Court

Defendant earnestly contends that Carley's top and bottom ropes were completely anticipated in the patent granted to Köpcke, No. 456621, July 28, 1921. Köpcke, it is true, was attempting the construction of a life preserver, but his ideas and Carley's ideas were decidedly distinct. Köpcke's invention embodied no idea of reversibility and in no way involved a roping system wherein draw ropes were to

Defendant's exhibit. Float made by the Athens Co. for the Government

function so as to attain rigidity at one point and requisite slack at another, furnishing the means for reversibility and collapsibility. Köpcke's netting to support passengers was made secure and was incapable of shifting, and was simply "securely fastened to the inner periphery of the ring, preferably by means of the rope d" for the single purpose of sustaining taut the netting relied upon as a bottom. Of course, when air was introduced into Köpcke's circular tubes the ropes became taut. Surely no claim may

Opinion of the Court

be advanced that this was the invention of a rope construction as the term is used in this case. One might well have examined the Köpcke patent in all its details without receiving a single suggestion useful to the construction of the Carley patent.

It is quite unnecessary to discuss an argument predicated upon the inoperativeness of the device d.sclosed in Carley's patent. One fact effectually disposes of the contention. The Government during the war adopted the device, used it extensively, and engaged the Athens Company to make it in numbers. The defendant as to this particular issue vigorously asserts the workability of Carley's first patent in order to predicate a defense of anticipation in the prior art, Carley's first patent having become public, and seemingly uses the same state of facts to demonstrate the inoperativeness of the patent in suit. The record does not sustain a contention that the patent in suit was inoperative. On the contrary, the longitudinal crisscross arrangement of the draw ropes is in exact accord with prior construction by the plaintiff in its shops, a fact which was publicly known and which is not proven to have been the single essential element of the patent vital to its operativeness. The defendant was fully acquainted with the patent in suit, knew its detail of construction, and was familiar with the types made and sold by the plaintiff. The record fully sustains the findings of the court in this respect.

The plaintiff is entitled to a judgment. The case will be remanded to the general docket as per stipulation of the parties for proof as to damages. It is so ordered.

Moss, Judge; GRAHAM, Judge; HAY, Judge; and CAMP BELL, Chief Justice, concur.