US338023A

US338023A - Edwakd m

Info

Publication number: US338023A
Authority: US
Publication date: 1886-03-16
Anticipated expiration: 1903-03-16

Description

(No Model.)

B. M. BENTLEY.

ELECTRIC MOTOR.

No. 338,023. 110 Patented Mar. 16, 1886.

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EDYVARD M. BENTLEY, OF BROOKLYN, NElV YORK.

ELECTRIC MOTOR.

SPECIFICATION forming part of Letters Patent No. 338,023, dated March 16, 1886.

Application filed July 10, 1885. Serial No. 171,198. (No model.)

To aZZ whom, it may concern.-

Be it known that I, EDWARD M. BENTLEY, a citizen of the United States, and a resident of Brooklyn, New York, have invented certain new and useful Improvements in Electric Motors, of which the following is a specification.

My invention consists in certain devices whereby two or more electric motors may be run at varying speeds in multiple are on the same circuit.

This invention is especially applicable to electric motors employed for the propulsion 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 ofcurrent is apt to be so great as toinjure or destroy them. I therefore provide a variable resistancein 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.

In the accompanying drawin M and M represent two electric motors, connected, respectively, to the driving-wheels of two elec tric locomotives. Each motor is provided with a lever, L, for shifting the position of the comn'iutator-brushes, and also with a lever, L,w hich controls an artificial resistance, R, in the motorcircuit. Both the commutator-brushes and the resistance may be controlled by a single lever, if desired. Upon each lever L 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, 0. adapted to engage with the teeth of sector A when the magnetis 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 mag net 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 preventstoo great a flow of current through any one of several motors in multiple arc.

\Vhat I claim as my invention is 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 currentin the motorcircuit.

3. The combination of two or more electric motors in multiple are on the same circuit, a resistance in circuit with each mechanism controlling the same resistances, and automatic stops for said mechanisms.

4. The combination, with two or more electric motors in multiple are, of a resistance in circuit with each mechanism controlling said resistances,aud 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 controlling the movement of said mechanism.

In testimony whereof I sign this specification, in the presence of two witnesses,this the 24th day of June, 1885.

EDXVARD M. BENTLEY.

Witnesses:

ALBERT E. LYNCH, CHAS. H. DORER.