Westinghouse Electric & Mfg. Co. v. Condit Electrical Mfg. Co.

194 F. 430, 1911 U.S. App. LEXIS 5440
CourtU.S. Circuit Court for the District of Massachusetts
DecidedDecember 28, 1911
DocketNo. 327
StatusPublished
Cited by4 cases

This text of 194 F. 430 (Westinghouse Electric & Mfg. Co. v. Condit Electrical Mfg. Co.) is published on Counsel Stack Legal Research, covering U.S. Circuit Court for the District of Massachusetts primary law. Counsel Stack provides free access to over 12 million legal documents including statutes, case law, regulations, and constitutions.

Bluebook
Westinghouse Electric & Mfg. Co. v. Condit Electrical Mfg. Co., 194 F. 430, 1911 U.S. App. LEXIS 5440 (circtdma 1911).

Opinion

HALE, District Judge.

This suit in equity raises the question of validity and infringement by defendant of claims 1, 3, and 4 of letters patent No. 570,416, issued October 27, 1896, to the complainant as assignee of A. J. Wurts. The patent relates to circuit-interrupting means for systems of electrical distribution. The claims in issue are as follows:

“1. In a multiphase system of distribution, the combination with a circuit-interrupter common to all the phases of the system, a normally open local' [431]*431circuit and a controlling-magnet included therein, of circuit-closers for the local circuit, one for each phase of the system, an overload upon any one of the main circuits serving to actuate its circuit-casing device and thus close the local circuit.”
“3. Tiie combination with a plurality of systems of electrical distribution provided with circuit-interrupting devices, controlling-magnets and normally open local circuits therel'or fed by an Independent source of current, of means actuated by an excessive current in any one of the main circuits for closing the corresponding local circuit, and a plurality of circuit-closing devices located at a distant point and each operated at will to close the corresponding local circuit.
"4. The combination with a plurality of systems of multiphase electrical distribution provided with circuit-interrupting devices, one for all of the phases of each system, and controlling-magnets- therefor, of a local circuit for each of said magnets, means actuated by an excessive current of any phase to close the corresponding local circuit, and a plurality of switches independently operated at will to close any one of said local circuits.”

In the specification the inventor, Wurts, describes the scope of his invention:

“My invention relates to circuit-interrupting means for systems of electrical distribution, and has particular reference in some of its more important features to multiphase circuits, though not in all respects limited to use in such relations. The objects of my invention are, first, to provide an actuating or controlling moans included in a normally open local circuit which is closed by the action of an overload in the main or distribution circuit, and preferably at a suitable predetermined interval after the occurrence of such overload ; second, to provide a circuit-interrupter common to all the phases of a multiphase system, with a controlling- or actuating magnet included in a normally open local circuit, which will be automatically closed by the action of an excessive current in a conductor for any one of the phases and preferably at a predetermined interval after the occurrence of such excess of current, and, third, to provide a means, located at a point more or less remote from the circuit breaker or breakers, whereby any one of a plurality of such circuit-breakers may be electrically controlled at will.”

The inventor then proceeds by diagrams to illustrate the details of his apparatus, and then states in general the results which he has sought to obtain:

“It is obvious from the illustration and foregoing description that, whenever the current in any one of the conductors exceeds a predetermined limit, all of the circuits from that particular generator will he automatically interrupted. It will also be understood that any number of generators and circuits,may be connected with the local circuit in the manner shown. It will also be understood that this use of a local circuit for energizing the controlling-magnet for the circuit-breaker may be employed in connection with a single-phase system of distribution, if desired, and hence I do not limit my invention to use in connection with multiphase circuits, as shown in the drawing. It being often desirable in large power-houses to open any one of several circuit-breakers from a given point, which may be more or less remote from such circuit-breakers, I extend the local-circuit conductors to the point from which it is desirable to actuate the circuit-breakers and locate at this point suitable 'circuit-closing devices, one for each circuit-breaker. These circuit-closing devices may be push-buttons or any other desired form of hand-operated means whereby the local circuit may he closed through any one of the controlling-magnets when it is desired to open the circuit-breaker with which such magnet is connected.”

In his testimony, the expert, Prof. Clifford, points out some elementary facts which relate to the art, and are important in the study of the case. He shows that the generation, transmission, and distribution of power electrically may be accomplished by either direct or by [432]*432alternating currents. A direct or continuous current maintains unchanged the direction of its flow in the electric circuit. In a direct current system, therefore* we are concerned with a sensibly steady flow of electrical energy already established. An alternating current alters its strength and reverses its direction in the circuit periodically with the passage of time, these variations of the current taking place according to a definite law. He further points out that alternating current systems are usually classified as either single-phase (monophase) or pofyphase (multiphase). A single-phase system generates, transmits, and distributes a simple or single alternating current. A poly-phase system generates, transmits, and distributes two or more such currents which may be combined in a number of different ways. The polyphase system 'is characterized as two-phase, three-phase, etc., according to the number of such simple alternating currents as are combined for purposes of utilization. The phase difference between two simple alternating currents is determined by the difference in time at which corresponding values of the currents in question occur.

It is further pointed out as a result of this well-known property of three-phase currents that, instead of having three complete circuits for the three phases of the current, what is called a “three-wire” system may be employed. Under this system, the current may flow outwardly over two wires and return through the third wire, or it may pass outwardly through one line and return through the other two lines; the outgoing and incoming currents being always equal. In a two-phase system, three wires may also be used instead of two complete circuits, the two currents flowing out on two of the wires and both returning by a third or “common return” wire.

[433]*433By means oí tlie foregoing diagram illustrating the Wurts patent, the learned counsel for complainant points out the leading elements of the patent, substantially as follows: The Wurts patent shows diagrammatically at 1, and also at 2, a “two-phase generator” provided with two conductors, 3, '!/, for the two phases of current and a common return conductor 5; so that in each of the two systems of distribution illustrated one current or phase flows round the circuit 3, 3, and the other current around the circuit 5. The conductors are shown as broken off at the bottom of the diagram, after passing through circuit-closers 6 and circuit-breaker contacts 7, 8, to be referred to, and the circuits are then supposed to be completed through the lamps, or whatever other objects are used as “translating devices” in the circuits.

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Bluebook (online)
194 F. 430, 1911 U.S. App. LEXIS 5440, Counsel Stack Legal Research, https://law.counselstack.com/opinion/westinghouse-electric-mfg-co-v-condit-electrical-mfg-co-circtdma-1911.