US359429A - Eliza - Google Patents

Description

w (No Model.)

B. P. CLARK.

' ELECTRIC MOTOR.

No. 359,429. Patented Mar. 15, 1887.

INVENTOR M $4M,

WITNESSES ATTORNEY UNITED STATES PATENT OFFICE.

ERNEST PAUL CLARK, OF NEW YORK, N. Y., ASSIGNOR OF PART TO ANN ELIZA APPLEGATE AND JAMES H.

SEYMOUR, BOTH OF SAME PLACE.

ELECTRIC MOTOR.

SPECIFICATION forming part of Letters Patent No. 359,429, dated March 15,1887.

Application filed November 23, 1886. Serial No. 219,703.

To all whom it may concern.-

Be it known that I, ERNEST PAUL CLARK, a citizen of the United States, residing; in the city, county, and State of New York, have invented certain new and useful Improvements in Electric Motors; and I do hereby declare that the following is a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention is concerned with providing means for increasing the efficiency of that class of devices known as electric motors. It has been found in practice that rotary electric motors are more eff cient when the pole-pieces of the armature pass in the closest possible proximity to the field-magnet poles, while the efliciency of dynamo-electric machines is not increased by such proximity. For example, taking the ring-armature as a type, it has been found that a smooth ring-armature like that of Gramme is the better form for a dynamo-electric generator, whereas the toothed ring-armature of Pacinotti is more effective for use in motors.

Now, in Letters Patent of the United States No. 330,005, granted to me on the 10th of November, 1885, I have shown and described a dynamo-electric machine in which I cause an armature of the Gramme type to rotate be tween internal and external field-magnet polepieces. My-present invention ris mainly di-- rected to making this machine an efficient motor. To this end I employ, in place of the Gramme ring, a Pacinotti ring with some alterations, and I find .that the results fully warrant the change of form. The ring of Pacinnotti was provided with external teeth or projections, between which the wire was wound. I'provide my ring with internal and external teeth or projections, those on the inside being narrowed so as to admit of the proper winding of the ring. I find that I secure far better results in this way than with a ring having the externalprojectionsalone.

In the accompanying drawings, which illustrate my invention and form a part of this specification, Figure l is a side elevation of the motor embodying my invention. Fig. 2 is a detail of the ring or core upon which the armature-coils are wound, showing also a section through the inner magnet pole-pieces; and Fig. 3 illustrates the form of my field-magnet cores and pole-pieces.

(No model.)

Referring to the drawings by letter, A and B are uprights or standards on which my motor is supported. On these standards, respectively, are mounted the magnets O and D, forming the field-magnets of my motor. The cores of the two upper helices of the said magnets are preferably formed in one casting, as are also those of the two lower helices of the respective magnets. The form of the castings is shown in Fig. 3, by reference to which it will be seen that each casting is so shaped as to present a pole-piece both within and without the rotating armature. The outer polepieces I have designated by the letter E, and the inner pole-pieces by the letter F. The armature G of my motor is mounted on a shaft, H, supported by the standards A and B. The armature-core is made in the form of a ring of iron having external teeth or projections, G, and internal teeth or projections, G". The armature is wound in the usual manner be tween the said teeth. By reference to Fig. 2 it will be seen that I re-enforce the inner polepieces by a magnet, I, whose helices stand at 'internal and external pole-pieces, I find that I bring the armature very effectually under the influence of .my field-magnets and secure a motor of high efficiency.

The operation of my motor is the same as that of other machines of its class, and I have therefore not described it in detail.

lVhat I claim is- In an electric motor, the combination, with a pair of field-magnets provided with external and internal pole-pieces, and a third magnet whose cores are joined to the said inner polepieces, of a ring-armature having external and internal projections, as and for the purpose set forth. s

In witness whereof I have hereunto affixed my name in the presence of two subscribing witnesses.

ERNEST PAUL CL ARK.

IVitnesses:

GEORGE H. STOOKBRIDGE, Onas. H. SAAL.

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