General Electric Co. v. Winsted Gas Co.

110 F. 963, 1901 U.S. App. LEXIS 4934
CourtU.S. Circuit Court for the District of Connecticut
DecidedSeptember 24, 1901
DocketNo. 916
StatusPublished

This text of 110 F. 963 (General Electric Co. v. Winsted Gas Co.) is published on Counsel Stack Legal Research, covering U.S. Circuit Court for the District of Connecticut primary law. Counsel Stack provides free access to over 12 million legal documents including statutes, case law, regulations, and constitutions.

Bluebook
General Electric Co. v. Winsted Gas Co., 110 F. 963, 1901 U.S. App. LEXIS 4934 (circtdct 1901).

Opinion

TOWNSEND, District Judge.

Suit for infringement of patent No. 342,504, applied for on November 8, 1882, and granted on May 25, 1886, to Rudolph Eickemeyer, for a magneto-electric and electromagnetic machine. The defendant is a mere user of a single machine. The real defendant is the Stanley Electric Manufacturing Company, of Pittsfield, Mass., which appears to be an entirely responsible party, and is engaged in the extensive manufacture of the alleged infringing machine; and no special reason is shown why this special user, instead of the.manufacturer, has been sued.

The patent in suit relates to unipolar or homopolar machines, so called. A unipolar or homopolar machine is one in which currents are generated continuously in the windings in one direction. It is a machine in which the lines of force are cut in one direction only, as distinguished from alternating current machines, in which the lines of force are cut in alternately opposite directions, and which require the use of commutators to straighten out the current. The pat-entee’s object was to produce a practical, commutatorless, continuous current machine. He states that hitherto “it has been necessary to use a device called a commutator,” and that “there are many disadvantages attending the use of * * * such commutator,” which do not arise in an apparatus in which the current “is induced in one di[964]*964rection”; and be says: “The object of my invention is to obtain such a machine.” He further states that, while such machines “have hitherto been devised by which a feeble continuous current can be developed, * * * so far as I am aware, no machine has been devised for practical purposes in the arts in which is embodied” his suggested mode of operation.

Perhaps the best example of the prior unipolar art, recognized by Eickemeyer as above, was the Siemens British patent, No. 3,134 of 1878, for unipolar generators. The Siemens illustrative drawing, introduced by defendant, shows an inner pole, A, surrounded by a revolving copper shell, b, and outside of this a cylindrical iron shell, A', the function of which was to concentrate the force and reduce the resistance of the magnetic circuit. The current passes up from the positive pole through the copper shell, and down through an external conductor to the negative terminal, thus making a complete magnetic circuit. This external shell did not completely inclose the exciting coils of the field magnet, and the magnetic circuit was irregular. This' machine and the publications relating to it showed the principle of connecting a plurality of armature conductors in a series in a single unipolar machine. Eickemeyer improved this construction by completely housing the exciting coils within the magnetic shells, thus preventing leakage, and by suppressing the outside return path, and placing his cylindrical conductors in a single annular magnetic field. The patentee further says (page 1, lines 63-74, of the patent):

“A characteristic feature of machines embodying my invention is the organization, with a magnet affording an annular field of force, of an armature which embodies two or more separate conductors, each of which, during its movement within said field of force, operates as an independent element, and is traversed by an electric current always in the same direction; and I have so organized said independent conducting elements that any two or more of them can be coupled in linear series.”

The essence of Eickemeyer’s improvement, thus described, consisted in taking the old unipolar, commutatorless, continuous current machine, and so coupling a number of separate and insulated conductors in linear series, constituting an armature by outside wires, as to increase the power of the current and get a higher continuous potential, varying according to the number of elements. He arranged two opposite cylindrical poles concentrically, so that the lines of magnetic force would flow from the outer to the inner pole, and be evenly distributed throughout the annular space between the two poles. Then he rotated a series of independent bars or conductors parallel to the axes of said cylinders, so as to always cut said lines of force in the same relative direction and generate a continuous current in one direction; he then added all the electro-motive forces together by coupling them together in linear series; that is, by connecting the positive terminal of one pole to the negative terminal of another, by the use of sliding contact rings and intermediate stationary external conductors. Counsel correctly says:

“In all of the machines devised by the patentee and claimed by him as of his own invention, the induced or armature circuit is made up of a series of independent bars or conductors, disposed in such a manner as to cut the [965]*965lines of the magnetic field of force always in the same relative direction;;- and these are coupled together in linear series by means of sliding contact, rings and intermediate, stationary, external conductors. * * * A; moment’s consideration of the conditions which are present in the machine -in question will suffice to show the purpose and result of this arrangement. All of the internal bars or sections of conductor, being parallel'to the axis; of rotation of the armature, generate currents in the same direction. To superimpose the currents in any two bars, therefore, so that their. electromotive forces may be added to one another, the positive terminal of the one must be connected to the negative terminal of the other; but, as all of the terminals at one end of the armature are positive and at the other negative,this can be accomplished only by the use of stationary paths exterior to the magnetic field of force, and with which the independent internal conductors are maintained in electrical connection through connecting rings and rubbing contacts.” , ,

Eickemeyer illustrates various forms of his alleged invention by some 42 figures, and (on page 6, lines 115-125, of patent) refers to the. special feature claimed to be appropriated by defendant as follows:

“It will be observed that, in many of the machines illustrated, the exciting'; helix or helices are inclosed within a mass of magnetic metal, which' is' chambered and which surrounds the armature, and that each helix is con-' centric with the axis of the armature, and that these parts, thus organized,' involve a novel feature, which I deem of value, in that the magnetic currents, or forces are thereby practically restricted to the interior portions of the machine.” •

Complainant’s counsel describes this construction and its advantages as follows:

“The particular feature exhibited by many of the forms of generator illus-' trated in the patent, and to which special attention is directed by the paragraph 011 page 0, lines 115 to 124, quoted above, will be seen to involve exte- . rior and interior cylindrical magnetic elements, between wliich are the eon-, volutions of the conductor or coils which impart magnetism unvarying in' direction to both. The exterior element is the inclosing frame or shell -of the machine. The interior element serves to complete the magnetic circuit, and thus to maintain a region of very intense magnetic force, within the in-' iluence of which are the armature or current-generating- coils.

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Bluebook (online)
110 F. 963, 1901 U.S. App. LEXIS 4934, Counsel Stack Legal Research, https://law.counselstack.com/opinion/general-electric-co-v-winsted-gas-co-circtdct-1901.