US361274A - James w - Google Patents

Description

no new. J. W. EASTON.

ELECTRIC MOTOR. No. 361,274. Patented Am. 19', 1887.

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N PETERi Plmninm n mr. washin im D40 UNITED STATES PATENT OFFIC JAMES XV. EASTON, OF NEW YORK, N. Y.

ELECTRIC MOXTOR.

SPECIFICATION forming part. of Letters Patent No. 361,274, dated April 19, 1887.

Application filed July 8, 1886.

To all whom it may concern:

Be it known that I, J AMES W. EAsTor a sub ject of the Queen of Great Britain, residing in 'New York, in the county and State of New magnets shall be reduced as much as possible,

. ter of their magnetic attraction.

and that thepoints of magnetic polarization of the armature should be so located as to be acted upon by the field-magnets to the best pos sible mechanical advantage.

Electro-dynamic motors are now usually constructed with ring-armaturesin much the manner of dynamo-electric generators. The fieldmagnets encircle a greater or less portion of the armature and tend to produce magnetism therein at the points nearly opposite the cen- The'magnetism induced in the armature by the action of its own coils should be at apoint removed from the centers of the field-poles adistance nearly equal to one-fourth of the circumference of the armature. The two forces tend, therefore, to form two different points of magnetic polarization in the armature and combine to establish a resultant polarization; but to a certain ex tent they neutralize each other. By removing the greater portion of the iron of the field-mag nets through the central portion of each pole the undesired effect from the poles is to a very great extent removed,'and the consequent magnetic poles of the armature are moved back to such positions that the attraction of the fields upon the armature will be expended to the best possible advantage to revolve the armature.

Serial No.207.0-15. (to model.)

In the accompanying drawings, Figure 1 is a longitudinal section, and Fig. 2 a transverse section,ofa motor embodying the features ofthe invention.

Referring to the drawings, A represents a ring-armature constructed upon the Gramme principle, and B B the poles of a field-mag net, B, applied thereto. The central portion of each fieldmagnet is removed, as showmat b and If, leaving two outer portions, 0 c and d d", to each field-magnet. By reason of this construction the magnetizing effect which the field-magnet has upon the armature is insufficient to cause the consequent poles of the armature to be at the points within or near the central line of the attraction of the poles; but they will be located at or near the points it and 8. Considering the pole-piece B to be north and the pole-piece B south, it will be evident that the attraction then exerted between the armatures and the field-magnet will be expended to the best advantage for revolving the armature, as it will be approximately tangential.

I claim as my invention-- ln an electric motor, the combination of an armature having polarized and neutral points, field-magnets acting upon the polarized points, which field-magnets have the central portions of their polar projections removed, and are thereby separated a greater or less distance from the neutral points of the armature, substantially as described.

In testimony whereof I have hereunto subscribed my name this th day of May, A. D. 1886.

JAMES V. EASTON.

Witnesses:

Tt-ros. TRYoN, CHARLES A. TERRY.

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