Improvements in or relating to Electric Motors.
Year: 1893

page_text: PROVISIONAL SPECIFICATION.
Improvements in or relating to Electric Motors.
1 IMLE E. STOREY of Boulder in the State of Colorado, United States of
America, Electrical Engineer, do hereby declare the nature of this invention to be
as follows:-
According to my improvements in or relating to electric motors I construct the
held magnet in the form of a cylinder adapted to surround a coil or coils of wire
and having pole pieces extending inward from a point or points about midway
between the edges of the said cylinder and extending laterally in both directions
towards the edges of the cylinder so as to embrace the coils. In combination with
this I arrange other pole pieces which extend from opposite points at the edges of
the cylinder around the said coil or coils and towards each other; these latter pole
pieces may conveniently be projections extending inwardly from end rings
connected together and secured to the cylinder by bolts suitably constructed and.
disposed.
The different pole pieces of this multipolar field magnet alternate with one.
another around the armature, and the exciting coils are confined between the
cylinder and the pole pieces.
Dated this 9th day of January 1893
J. C. CHAPMAN,
Agent.
COMPLETE SPECIFICATION.
Improvements in or relating to Electric Motors.
I, IMLE E. STOREY, of Boulder in the State of Colorado United States of
America, Electrical Engineer do hereby declare the nature of this invention and in,
what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement :-
This invention relates to electric motors, and the object is to provide a
construction which shall be as compact and symmetrical as possible, simple,
efficient, and protected from external injury.
The invention consists of the construction which will be hereinafter described
and claimed.
In the accompanying drawings,
Figure 1 is a perspective view of the motor. Fig. 2 is a longitudinal section of
the same. Fig. 3 is a similar section, but taken at right angles to Fig. 2 and with
the armature removed; and Fig. 4 is a transverse section.
The general exterior appearance of the motor is tubular or cylindrical, the
middle portion A constituting a part of the field-magnet. Inside of the cylinder
and close against its interior walls are located two field-magnet coils A A, which
[Price Bl

page_text: are separated from each other by a short space A². At points diametrically
opposite each other are formed inward radial projections a from the cylinder,
which pass between two coils and the inner ends of these have lateral projections a¹ a¹,
forming a T, which extends across the full width of the coils A'. These constitute
two of the field-magnet pole-pieces, and their inner surfaces are cylindrical in 5
shape and parallel to the axis of the motor. At points ninety degrees from
each of these pole-pieces are formed other pole-pieces a², which are continuations
of the end of the cylinder, formed around the outer edges of the coils and
extending inward towards each other until they nearly meet at a point in the
middle of the space A. Each pair of these formations a² constitute another pole- 1
piece of the motor. The pairs are placed diametrically opposite each other and
alternate at equal distances around the interior of the cylinder with the pole-pieces a¹.
For convenience in the construction the pole-pieces a² are cast or otherwise formed
upon rings A³, which are closely fitted to the cylinder A at the points a³ a³. These
rings have inward radial flanges, as shown, which are connected together by brass 1
bolts a', which rigidly hold the cylinder and the rings together as one structure.
Small flanges a are also formed upon the rings, for a purpose which will
hereinafter appear. The electric current is to be passed through the coils A¹ A¹
in such directions as will produce magnetic polarity of one sign in all of the
pole-pieces a¹ and a polarity of the opposite sign in all'of the pole-pieces a². The 2
motor is, therefore, a four-pole machine, the magnetic circuit 'being from one
pole-piece through the armature to the other, around the coils, and 'through the
outer cylinder.
"
The armature B of the machine may be of any approved 'type. I have shown:
it as a Gramme ring supported by a three-arm spider b. The latter is keyed to a 2
tube or sleeve upon the armature-shaft C. The shaft has its bearings in boxes c,
formed in arms or heads c', cast upon or bolted to the end rings A³, and these arms
or heads are covered by cup-shaped castings or parts c², the edges of which are
riveted or screwed to the flanges a on rings A³, and the centre is open to
embrace the box c. These parts therefore entirely inclose the ends of the 3
motor, and together with the cylinder of the field-magnet, constitute a water and
dust proof housing for all the moving and delicate parts. One of the end housings
is made longer than the other and covers the commutator, D and brush-holder d,
which are located on the shaft and box c, respectively.
feet e;
As a stationary motor, the field-magnet cylinder should have formed upon it the 3
but for street-car or locomotive work the cylinder is perfectly plain.
Although I have described a four-pole motor, it is obvious the invention applies to
any multi-polar machine..
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I 4
claim is:
1. In an electric motor, a field-magnet consisting of a cylinder surrounding a coil.
or coils of wire, in combination with pole-pieces extending from opposite points at
the edges of the cylinder around the coil or coils and toward each other, and other
polė-pieces extending inward from a point or points about' midway between 'the '4
edges of the cylinder and extending in both directions toward the edges of the'
cylinder and embracing the coils, substantially as described.
1
2. The combination, with an armature, of a multipolar field-magnet consisting of
a cylinder surrounding the armature and having pole-pieces projecting from its
edges inward and other pole-pieces projecting from its middle portion inward, the 5
different pole-pieces alternating with one another around the armature, and
exciting-coils confined between the cylinder and the pole pieces.
3. The combination, with the cylinder A, provided with one set of pole pieces, of
the end rings provided with the inward projections, constituting the other set of
pole picces, as set forth.
I
5

page_text: 4. The combination, with the cylinder A, provided with one set of pole-pieces,
of the end rings provided with the inward projections constituting the other set of
pole pieces, and bolts, as a, connecting the two rings and securing them to the
cylinder, substantially as described.
Dated this 11th day of January 1893.
J. C. CHAPMAN, C.P.A.,
70, Chancery Lane, London, W.C., Associate Agent for Applicant.