General Electric Co. v. Brooklyn Heights R.

118 F. 154, 1902 U.S. App. LEXIS 5183
U.S. Circuit Court for the District of Eastern New York·Decided May 29, 1902·Published·Cited by 1 cases

Opinion

THOMAS, District Judge.

This action involves the infringement of letters patent No. 338,023, issued March 16, 1886, which relate to electric motors,—especially those employed upon railroads. The inventor states the mischief which his patent was designed to remedy, as follows:

“My invention consists in certain devices whereby two or more electric motors may be run at varying speeds in multiple arc on the same circuit. This invention is especially applicable to electric motors employed for the impulsion of vehicles upon an electric railway. It is well known that when two or more electric motors are in multiple arc with one another, and run at variable speeds, 'those motors which run the more slowly will tend to absorb an undue portion of the current, while those which are running at a greater speed will be deprived of the necessary amount of current. This tendency is a source of danger to the slow-running motors, since the surplus of current is apt to be so great as to injure or destroy them. I therefore provide a variable resistance in the circuit of each motor, and also provide a catch or stop which will automatically prevent the removal of too great an amount of resistance from the motor-circuit.”

[155] Thereupon the mechanism is described in the language placed below the following figures:

“In the accompanying drawing, M and M' represent two electric motors, connected, respectively, to the driving-wheels of two electric locomotives. Each motor is provided with a lever, L, for shifting the position of the commutator-brushes, and also with a lever, L', which controls an artificial resistance, R, in the motor-circuit. Both the commutator-brushes and the resistance may be controlled by a single lever, if desired. Upon each lever, I/, is a toothed sector, A, concentric with the. axis of the lever, and in each motor-circuit is an electro-magnet, S, whose armature has a pawl, O, adapted to engage with the teeth of sector, A, when the magnet is energized. The magnet, S, is adapted to respond only to an excess of current beyond a determined point. The operation of this arrangement is as follows: Suppose that the operator of the motor has brought it to a standstill by the insertion of the resistance, R, or by the movement of the brushes, or both. Should he now desire to start the motor under a heavy load, or in a situation where the motor may be blocked in any accidental manner, he would in the usual manner throw his lever, cutting out the resistance, R, and there would result a sudden flow of current through the motor, which would destroy it before it could overcome the inertia of its load or its block, were-it not for the action of magnet, S. The magnet, S, becoming energized when the current reaches a predetermined maximum point, draws up its armature and interposes the pawl, O, in the path of any further movement of the resistance-lever, so that a driver will be warned that his current is too great, although he cannot by any degree of carelessness or haste permit the motor to be injured. Various modifications of this device may be employed, the underlying principle of them all being illustrated in the present device, wherein an automatic stop prevents too great a flow of current through any one of several motors in multiple are.”
Superadded are the claims, all of which are alleged to be infringed:
“(1) The combination, with an electric motor, of a resistance in circuit therewith, mechanism controlling said resistance, and an automatic stop for said mechanism. (2) The combination, with an electric motor, of a resistance in circuit therewith, mechanism controlling said resistance, and an automatic stop for said mechanism responding to an abnormal increase of current in the motor-circuit. (3) The combination of two or more electric motors in multiple arc on the same circuit, a resistance in circuit with each mechanism [156] controlling the same resistances, and automatic stops for said mechanism. (4) The combination, with two or more electric motors in multiple arc, of a resistance in circuit with each mechanism controlling said resistances, and automatic stops for said mechanisms responding to an abnormal increase of current. (5) The combination, with an electric motor, of a resistance in circuit therewith, mechanism controlling said resistance, and means for automatically i controlling the movement of said mechanism.”

More briefly stated, Bentley invented a system whereby a magnet in the main circuit, energized to a certain point, attracts and sets a pawl, which locks and makes immovable a lever with which the operator cuts out the resistance. With a reduction of the current to-a desired point, the magnet relieves the pawl, and the operator continues his removal of the resistance. The complainant’s invention is-the automatic application of a stop or lock to the operator’s lever,, when and while there is an excess of electric energy, by means of a pawl attractéd and held by a magnet while the excess continues. It may now be considered whether the defendant uses this or equivalent means for obtaining the same result. The defendant’s device-is described by one of its experts in the language placed below the following figure, to which it refers:

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General Electric Co. v. Brooklyn Heights R., 118 F. 154, 1902 U.S. App. LEXIS 5183 (circtedny 1902).

118 F. 154 (General Electric Co. v. Brooklyn Heights R.) — published by Counsel Stack Legal Research, free access to 12M+ legal documents.

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