US321147A

US321147A - Frank j

Info

Publication number: US321147A
Authority: US
Publication date: 1885-06-30
Anticipated expiration: 1902-06-30

Description

(No Model.)

'P. J. SPRAGUE.

ELEGTRO DYNAMIC MOTOR. No. 321,147. Patented June 30, 1885.

N. PiTERS, Phuto-Lilhugm hu, Walhinglnn. D, c

UNITED STATES PATENT Orricrt.

FRANK J. SPRAGUE, OF NEV YORK, N. Y., ASSIGNOR TO THE SPRAGUE ELECTRIC RAILWVAY AND MOTOR COMPANY.

ELECTRO-DYNAMIC MOTOR.

SPECIFICATION forming part of Letters Patent No 321,147, dated June 30, 1885.

(No model.)

To aZZ whom it may concern:

Be it known that I, FRANK J. SPRAGUE, of New York, in the county and State of New York, have invented a certain new and useful Improvement in Electro-Dynamic Motors, of which the following is a specification.

In the operation of a shunt-wound electrodynamic motor on a circuit of constant difference of potential it is desirable when the motor is started to have a strong field-magnet and little current in the armature-circuit, and then to gradually increase the difference of potential at the armature-circuit terminals, and then to gradually weaken the field-magnet, so as to progressively increase the speed of the motor and when the motor is running it is desirable, in order to change the speed or power, or both, of the motor, or to maintain the speed constant or practically constant under varying loads, to change the strength of the field-magnet without affecting the armaturecircuit, while in other cases, as in some circumstances which arise in the operation of moving motors on electric railways, it is desirable to vary the armature-current without affecting the field magnet strength.

To enable these various regulations to be readily performed is the object of the present invention.

In accomplishing this obj ectI provide means independent of each other for regulating the armature-current and the field-magnet strength, respectively. Thearmatureregulatingmeans is preferably an adjustable resistance in thearmaturecircuit, and the regulator for the field-magnet may be an adjustable resistance or other known device or construction for this purposesuch, for instance, as those set forth in my prior applications for patents.

My invention is illustrated in the accompanying drawings, in which Figure 1 is a diagram of a motor provided with regulating devices embodying my invention, and Fig. 2 a similar diagram showing a diiferent fieldmagnet regulator.

1 2 are main conductors of a supplying-circuit, preferably a circuit of constant difierence of potential, with which I prefer to use my invention. 3 4 is the armature-circuit, and 5 6 the field-circuit of a shunt-wound electrodynamic motor A. In the field-circuit 5 6 is an adjustable resistance, B, Fig. 1, and in the armature-circuit 3 4 is an adjustable resistance, C. It will be seen that each of these resistances is controllable independently of the other. Thus to increase the strength of the field-magnet a portion of the resistance Bis cut out of circuit, and to decrease its strength more of the resistance B is placed in circuit. Thus the regulation of the field-magnet is performed without affecting the armature-circuit. The current in the armature is similarly controlled without affecting the field-magnet by the adjustment of the resistance 0. The regulating means for the two circuits may include, also, a circuit-reverse for each circuit D or D, whereby the current in either circuit is reversed without affecting the other circuit.

The field-magnet regulator shown in Fig. 2 consists of a circular commutator, E, to the blocks of which are made connections 7 7, from the bights of sections into which the fieldmagnet coils are divided, such sections being connected together into a continuous closed circuit, and each section being wound from end to end of the core, although in the drawings, for convenience of illustration, the sections are placed side by side on the cores. The supplying terminals of the field-coils are connected with the two pivoted arms a a on the commutator E, and by moving said arms upon the commutator the current is reversed in more or less of the field-coil sections, whereby the strength of the field-magnet is varied independently of the armature. As this apparatus also may effect the reversal of the field magnetism, the currentreverser D is here dispensed with. v

In the armature-circuit is an adjustable resistance, O, and circuit-reverser D, whereby the armaturecircuit is independently rcgulated, as before.

The reversing-switches may be used to make and break the circuits, or additional circuitcontrolling switches may be provided.

The arrow-heads in the drawings show the direction of current in the circuits.

It is evident that my invention is applicable to the armature and main-field circuits of that class of shunt-wound motors having diiferen- 1C0 tial coils in series with the armature, although it is set forth with relation to a simple shuntwound machine.

\Vhat I claim is- 1.. A shunt-wound eleotro-dynamic motor provided with means for varying its armaturecurrent and independent means for varying the strength of its field-magnet, substantially as set forth.

2. A shunt-Wound electro-dynamic motor provided with means for varying the strength of its field-magnet and with an adjustable resistance in its armature-circuit, substantially as set forth.

3. The combination, with a shunt-Wound electro-dynamic motor, of independently-adjustable resistances in its armature and fieldcircuits, substantially as set forth.

4:. The col'nbination, with a shunt-wound electro-dynamic motor, of a circuit-reverser, and an adj list-able resistance in its armaturecircuit, and means for varying and reversing its field magnetism, substantially as set forth.

The combination, with a shunt-wound electro-dynamic motor, of a circuit 'reverser, and an adjustable resistance in its armaturecirouit, and a circuitreverser and an adjustable rcsistance in its field-circuit, substantially as set forth.

This specification signed and witnessed this 24th day of February, 1885.

FRANK J. SPRAGUE.

WVitnesses:

A. W. RIDDLE, E. O. ROWLAND.