General Electric Co. v. Winona Interurban Ry. Co.

183 F. 418, 105 C.C.A. 652, 1910 U.S. App. LEXIS 5067
Court of Appeals for the Seventh Circuit·Decided October 4, 1910·No. No. 1,688·Published

Opinion

SEAMAN, Circuit Judge

(after stating the facts as above). The Kurda patent, No. 600,228, for a “polyphase-current transformer,” was granted March 8, 1898, and purchased by the appellant, General Electric Company, January 4, 1902; and these further facts are uncontroverted: Utility of the device as a unitary transformer of more than one alternating current in an electric system; extensive manufacture by the appellant of the patent transformers, with a profitable branch of business in their use by the trade; and invasion of the prima facie right of monopoly under the patent, by the defendants as charged in its bill. The sole defense tendered by the testimony, as frankly stated in the argument on behalf of the appellee, “is that the patent in suit is invalid in view of the prior art” — in substance for want of patentable invention — and the technical difficulties involved in the special subject-matter of “polyphase currents” tend to increase the usual difficulty arising under that issue. While the patent specifications refer to prior transformers for polyphase currents as of another type, using a group of single-phase transformers of the “core type” placed side by side, and that none were of the “ironclad type” adopted for the patent device, the evidence shows prior patents for transformers approximating so closely the means and function of this improvement that the margin is narrow for distinction therein between invention and exercise of the skill of an electrical engineer.

The patent transformer deals with the complicated problem of utilizing two or more alternating electric currents, as distinguished from a direct current, to transform the changing values of such currents into the desired electric energy. It is of the ironclad or shell type, as distinguished from the core type, and economizes material and space through its unitary structure. The specifications describe the invention as consisting “in arranging the electromagnets one above the other instead of placing them side by side, as heretofore, thus giving the electric magnets a common vertical axis.” In the prior Dobrowolsky patent, No. 422,746, granted March 4, 1890, for a transformer for polyphase currents, the structure is alike unitary, with the three cores (A, B, and C) shown in the patent drawings as placed radially, although other embodiments are in evidence arranging them directly “side by side”; and the appellant contends, in substance, for distinction therefrom: That “the transformer of the Kurda patent in suit is a specific improvement in unitary polyphase transformers embodying the Dobrowolsky principle, characterized by having ‘common mag[421] netic circuits’ ”; that the Kurda electromagnets (primary and secondary coils) placed “one above the other,” and “mounted upon a common core or axis, are surrounded and separated by iron pieces” thus obtaining the common magnetic circuit; that such combination is novel and “the gist of Kurda’s invention, as covered by claim 1”; and that further invention appears in reversing the middle set of coils, covered by claim 2, whereby “marked economies are obtained,” as conceded by the appellee’s expert.

The above-mentioned Dobrowolsky patent was considered and upheld by this court, in an infringement suit brought by the present appellant, as owner thereof (Kuhlman Electric Co. v. General Electric Co., 147 Fed. 709, 78 C. C. A. 97), and the opinion in that case furnishes sufficient description and definition of the patent; and in reference to the appellees’ contention here, not only of complete anticipation of Kurda by Dobrowolsky, but that, such prior patent having expired in the hands of this appellant, it “now seeks to again obtain monopoly of polyphase transformers by means of the Kurda patent,” we remark that, monopoly in production and use being the legitimate purpose of the grant, the sole test of right thereto is the validity and scope of the patent. It plainly appears that Kurda succeeded in his quest for economy in material and form over prior devices, for a commercial transformer, and, if liis product discloses invention to that end, the purchaser is entitled to the protection sought in exclusive use.

In the argument to defeat the patent various propositions are urged, with reference to the prior art, which may be summarized as follows: (a) that Kurda’s transformer differs from Dobrowolsky’s only “in form of mechanical construction,” with “no different function and operation and secures no new or different result,” and “no advantages over the use of three single-phase transformers not previously obtained by Dobrowolsky”; (b) that after Dobrowolsky “the particular form of other polyphase transfonners became merely a matter of-design and not of invention”; (c) that Kurda’s transformer “is merely a natural union of single-phase shell-type transformers in view of polyphase transformers such as Dobrowolsky”; (d) that claim 1 of the patent “is anticipated in every respect by the earlier Ilutin & Leblanc ¡latent,” and as well by other patents; and (e) that “claim 2 involves no invention over the prior art.” We believe, however, that solution of the issue rests upon the inquiry above stated of patentable invention, as a commercial improvement over Dobrowolsky, in the light of the prior art; and that such inquiry does not involve reconsideration of the issue settled in Kuhlman Electric Co. v. General Electric Co., supra, that the “union of single-phase shell-type transformers” in a unitary transformer for polyphase currents was invention in Dobrowolsky’s transformer, and not therefore an obvious expedient. Until means were devised to obtain common magnetic circuits in a unitary structure, such union of single-phase transformers was necessarily inoperative. The question, therefore, is this: Are Kurda’s means to that end, for economic improvement, as stated in either'or both claims, differentiated from Dobrowolsky’s transformer, plus the prior art, so that invention is disclosed therein?

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General Electric Co. v. Winona Interurban Ry. Co., 183 F. 418, 105 C.C.A. 652, 1910 U.S. App. LEXIS 5067 (7th Cir. 1910).

183 F. 418 (General Electric Co. v. Winona Interurban Ry. Co.) — published by Counsel Stack Legal Research, free access to 12M+ legal documents.

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Kuhlman Electric Co. v. General Electric Co.
147 F. 709 (Seventh Circuit, 1906)