US451870A - hewett - Google Patents

Description

(No Model.) 5 Sheets-Sheet 1.

EM. G. HEWETT,

ELECTRIC MOTOR.

No. 451,870. Patented May 5, 1891.

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' (No Model.) 5 Sheets-Sheet 2.

E. M. G. HEWETT.

ELECTRIC MOTOR.

No. 451,870. Patented May 5,1891.

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' E. M. G. HEWETT.

ELEGTRIG MOTOR.

- No. 451,870. Patented May 5,1891.

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ELECTRIC MOTOR.

No. 451,870. Patented May 5,1891.

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v ELECTRIC MOTOR. N 0. 451,870.

Patented May 5, 1891.

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ERNEST M. GARDNER HEWETT, OF BOSTON, MASSAOHUSET' S, ASSIGNOR TO ALBERT L. JEVELL, OF SAME PLACE.

ELECTRIC MOTOR.

SPECIFICATION forming part of Letters Patent 1\T0.451,870, dated May 5, 1891.

Application filed November 14, 1890. Serial No. 371,469. (No model.)

To aZZ whom it 72mg concern.-

Be it known that I, ERNEST M. GARDNER HEWEIT, a citizen of the United States, residing at Boston, in the county of Suffolk and State of Massachusetts, have invented certain new and useful Improvements in Electric Motors; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others to skilled in the art to which it appertains to make and use the same.

This invention relates to electric motors.

The object of the invention is in a simple and efficient manner to convert electrical e11- 5 ergy into mechanical force; furthermore, to produce a cheap and efficient electric motor the armature whereof shall be of such construction as to require no winding, and which will permit of its being made of soft-iron bars so arranged with relation to suitable fieldmagnets as to operate with as great or greater efficiency than a motor having the ordinary wound armature.

With these objects in view the invention consists in an electric motor comprising a series of circularly-arranged electro-magnets, an armature composed of bars of soft iron or other suitable substance, similarly arranged, and a commutator whereby the entire current 0 employed is passed through each segment of the commutator in turn, is at no time divided, and the electro-magnets are each energized in turn to act upon abar of the armature, and each electro-magnet will exert attractive force 3 5 several times andwill have several strong pulls during each complete revolution. This being the invention, the same may be embodied in the most varied forms by those skilled in the art without departing therefrom.

0 In the accompanying drawings, forming part of this specification, and in which like letters of reference indicate corresponding parts, Figure 1 is a side elevation of a machine, illustrating an embodiment of the invention,

4 5 wherein the circularly-arran ged field-magnets are stationary and outside and bars of soft iron are revoluble therein. Fig. 2 is an end,

view from the supply end with the stationary end plate of the frame removed, showing the o stationary field-magnets in a stationary frame and their pole-pieces with conducting-wire to each magnet from a common supply, showing also bars of soft iron in a revoluble frame fixed on the revolving shaft. Fig. 3 is an end view from the discharge or take-off end, showing the commutator divided into segments, a wire from each magnet leading to a corresponding number of segments, and the entire number of segments being a multiple of the number of bars with the number of magnets. Fig. 4: represents a stationary commutator with one end of each coil connected to a segment thereof, this segment being connected with others by a suitable device-in this instance a ring-whereby the number of each set of connected segments will be equal to the number of armatures. Fig. 5 represents a diagram illustrative of the connections between corresponding segments, the lines showing contact-points of superimposed rings, 7c the rings correspondingin number with the number of electro-magnets. Fig. 6 is a diagram showing the connections between the field-magnets and the commutator for a group of five field-magnets, and Fig. 7 is a diagram 7 5 showing the connections between the fieldmagnets and the commutator for a group of seven field-magnets.

Referring to the drawings for the present form or embodiment, the details of which may be greatly varied without departing from the real invention involved, A represents stationary electro-magnets having elongated pole-pieces a, the magnets, with their polepieces, being fixed in a stationary frame A, made of brass or of other diamagnetic metal,

in order magnetically to insulate their polar ends.

B represents bars of soft iron or other magnetic substance capable of being attracted by an electro-magnet set in a revoluble frame, this frame being fixed upon the shaft (1 and turning therewith. The shaft has its bearings at one end in a metallic strap 0 and at the otheriu across-barc Fixed to,but insu- 5 lated from, the cross-bar c is a stationary commutator D, composed of a number of metallic segments (1, equal here to the product formed by multiplying the number of electromagnets with that of the armatures. Between the segments is a space or insulation greater in width than the bearing surface of the brush, the purpose being to prevent division of the current and avoid any attraction, retardation in motion, or holding of one bar by one magnet while another bar is being attracted by another, so that the entire current will pass through the segments in turn without division. The insulation is marked D Fixed upon and turning with the shaft at the commutator is a commutator-brush D the arm (1 of which is in metallic connection with the shaft. From a battery a current is supplied to a wire E,and this wire connects with the supply end of the coil of each of the electro-magnets by wires 6. At the other end the coil of each electro-magnet connects with a wire 6 with an adjacent segment of the commutator, so that as many adjacent segments of the commutator have wires fixed to them as there are electro-magnets. Vithin the commutator is arranged a number of rings F, the number corresponding with the number of electro-magnets. These rings are superimposed one upon the other, but are separated by suitable insulation F Each of the segments to which wires lead is in metallic connection with a ring, and each ring is, furthermore, in metallic connection with segments to which no wire leads, the whole number of segments with which a ring is in contact corresponding with the number of armatures.

It will of course be understood that the corresponding segments may be connected by suitable wires instead of by the rings or otherwise.

The operation will be as follows: The current enters by the common wire and passes by one of the branch wires through the coil of an electro-magnet, either directly or by a ring, to a segment of the commutator wherever the brush happens to be, thence through the brush and its arm, through the shaft back to battery, causingthe particular electro-niagnet to attract one of the bars and turn the revoluble frame, and from this the shaft, and thus the brush, moving it to the next segment. Under the present arrangement of, five electro-magnets and four armatures the armature will have been removed onetwentieth part of one revolution, and the brush will be placed in contact with the next commutator-segment for current through the next electro-magnet, and so on up to the fifth segment, which will bring the current through the fifth electro-magnet from the beginning. Then the brush passes to the next commutator-segment, and the current comes through the first magnet again; but the brush has only made one-fourth of a revolution, and yet the first magnet begins work again. By the time the brush passes the next five segments the first electro-magnet will again be at work, and by the time it passes the next five segments it will again be at work, so that inbut one revolution each electro-magnet will exert attractive force several times, as many times, in fact, as there are multiples of the number of segments corresponding with the number of electro-magnets, and each time that this number of segments is passed work will begin from the first electro-magnet again.

It will be understood that instead of having a stationary commutator and revolving brush there may be a revolving commutator and stationary brush, if that wherewith the commutatorconnectsrevolves. Instead of five electro-magnets, there may be seven or any othernumber,itbeingneccssary,however,that if the number of electro-magnets be odd the number of the armature-bars shall be even; but, instead of having the electro-magnets stationary and the brush revoluble, the brush may be stationary and the electro-magnets revoluble, as will be well understood by those skilled in the art. The arrangement shown, however, is preferred.

Having thus fully described my invention, what I claim as new, and desire to secure by Letters Patent, is-

An electric motor comprising a series of electro-magnets, an armature composed of bars of soft. iron, and a commutator consisting of a number of segments arranged in sets, each set containing a number of segments corresponding to that of the electromagnets, a series of plates placed within the segments, and of a number corresponding to the number of electro-magnets, and provided with projections each of which engages one of the segments of each set, a brush having a bearing-surface less than the width of each interval between segments, and suitable electrical connections whereby each electro-magnet is energized by the entire current only several times during each revolution of the armature, substantially as described.

In testimony whereof I affix mysignature in presence of two witnesses.

ERNEST M. GARDNER IIEWE'P'I.

Witnesses:

DAVID ll. MEAD, T. B. KEEFER.

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