IMPROVEMENTS IN ELECTRO MOTORS
Year: 1884

page_text: I, THOMAS CUTTRISS, of New Briggate, Leeds, in the County of York, Electrical
Engineer, do hereby declare the nature of my Invention for "IMPROVEMENTS IN
ELECTRO MOTORS," a communication to me from Abroad by Charles Cuttriss of
Duxberry, Massachusets, in the United States of America, to be as follows:--
The said invention relates to that class of Machines constructed to convert the
force of an electrical current into rotary motion, and is designed to do so with more
efficiency than heretofore, whilst at the same time the rotation is produced without
any dead points, and is easily reversible, the coolness in working being maintained
by free exposure of the parts to the air.
To effect this purpose:-upon a shaft, free to rotate in suitable bearings mounted
on a frame, are fixed two or more ring armatures surrounded as to their rims by a
series of coils of insulated wire wound or connected up so that each pair of coils
generate like electro magnetic poles at the point between any two of the coils. In
a series of such coils the poles will be alternately North and South between ench
pair successively.
The cores of the armatures may be made up of any suitable number of pieces
bolted on to a spoked hub, keyed to the rotating shaft. At the points also where
the magnetic poles are developed in the armature, additional pole pieces of any
suitable shape may be attached or may be formed out of the solid core of the
armature.
Where two or more armatures are used upon a single shaft, the poles between
the coils are distributed upon the circumference of the armatures, so as to inter
space with one another, so that when one set of poles is satisfied and of none effect
the others are being powerfully attracted.
Stationary with the frames are fixed two or more electro magnets, the poles of
which correspond in number to the poles upon the revolving armatures.
These field electro-magnets are constructed in either of the following ways:―
First side by side with the revolving armatures hereinbefore described are
fixed similar rings wound also with insulated wire, so wound or connected up as
to produce alternate North and South poles similar in number to those of the
armatures.

page_text: These field magnet rings are attached to external bars, parallel to the rotating
axis, and fixed to suitable end frames.
Second: the field electro magnetic poles are formed by winding insulated coils
of wire upon two or more cores, which may be either straight chords or curved
segments of a circle exterior to the armature. The ends of these cores are bent
inwards, forming poles which surround and enter between the two or more
revolving armatures. These segmental field magnets are fixed to a suitable
framing and are preferably so far apart that their bent poles become uniformly
interspaced about the circle through which the armatures revolve. The poles in
this case are alternatively of opposite signs.
To further distribute the magnetic field between the revolving armatures pole
plates may be added to the aforesaid poles between and outside the revolving
armatures..
The electrical circuits are completed in the following manner.
The extremities of the Coils upon the armatures are connected to insulated bars
upon a commutator or commutators, so that the current of electricity, conducted to
and away from the commutator by the usual contact brushes, is caused to reverse in
the armature coils as the poles' therein become satisfied, by passing the fixed
attracting poles of the electro magnets.
The magnetism of the fixed electro magnets does not change and may be pro-
duced by either a series or shunt circuit from the main current supplying the
Electricity to the Motor.
Reversal of the motor may be easily effected by rotation of the Contact brushes
around the commutator, the-brushes-being-mounted on a frame which is capable of
rotation round the axis of revolution.

page_text: 1, THOMAS CUTTRISS, of New Briggate, Leeds, in the County of York, Electrical
Engineer, do hereby declare the nature of my invention for "IMPROVEMENTS IN
ELECTRO MOTORS " a communication to me from abroad by Charles Cuttriss, of
Duxbury, Massachusetts in the United States of America, and in what manner the
same is to be performed, to be particularly described and ascertained in and by the
following statement:-
The said invention relates to that class of machines constructed to convert the
force of an electric current into rotary motion, and is designed to do so with more
efficiency than heretofore, whilst at the same time the rotation is produced without
any dead points, and is easily reversible, the coolness in working being
maintained by free exposure of the parts to the air.
In order that the said invention may be the better understood, I now proceed to
describe the same, reference being had to the drawings hereto annexed, and to the
letters and figures marked thereon. Liko letters refer to similar parts in each of
the different figures.
Figure 1 is an elevation of one alternative form of my improved electro motor.
Figure 2 is a transverse section through the same.
Figure 3 is an elevation of an alternative form of my improved electro motor.
Figure 4 is a transverse section through the same.
Figure 5 is a diagrammatic representation of the course and effects of the
electrical current.
Figuro 6 is a detail of the magnet pole pieces employed in the electro motor, as
shown at Figure 1.
Figure 7 is a detail of the field magnet pole piece, employed in the electro
motor as shown at Figures 3 and 4.
Figure 8 is a detail of the magnet core for the same.
The armatures in both motors are the same and are constructed thus:-
Upon the shaft A, free to rotate in suitable bearings B B, mounted on the
frame C, are fixed two or more ring armatures D D, with their poles uniformly
interspaced to one another in adjacent armatures on the same shaft. The armature
cores E E are conveniently divided into two parts, forming a square figure with
the corners rounded off, and screwed home on the spokes D¹ D₁ of the armature
frames or hubs. But a greater number of electro magnets, forming a regular
polygonal figure may be employed to form larger armatures. The poles E are
formed at the corners of the square armature, or at the corners of any polygonal
armature, thus forming in the motor illustrated, a series of 8 successive poles in
the two combined armatures. The intermediate cores between these poles, forming
the rim of the armature, are wound with a series of coils of insulated wire, so
connected up (as hereinafter more fully explained in the current diagram) that
each pair of coils on a single armature generate like electro magnetic poles at the
points between any two of the coils, which are thus alternately north and south.
The cores of the armatures may be made up of any suitable number of pieces, and
at the points where the magnetic poles are developed, additional pole pieces of any
suitable shape may be attached to or formed out of the cores of the armature.
Owing to the interspacing of the poles in adjacent armatures upon the same shaft,
when one set of poles is satisfied and of none effect, the others are being powerfully
attracted, and thus rotation is produced without dead points.
Stationary with the frames are fixed two or more electro magnets F F, the
poles of which G G correspond in number to the poles upon one of the revolving

page_text: armatures. These field electro magnets are constructed in either of the following
preferable ways.
1st The field magnets are formed, as in Figures 1 and 2, by winding insulated
coils of wire upon two or more cores F F, segments of a circle exterior to the
armature. The ends of these cores G G, forming the poles, (as shown in detached
detail figure 6) are bent inward forming prongs or pole pieces, which surround and
enter between the two or more revolving armatures. These segmental field
magnets are fixed to a suitable framing, and are preferably so far apart that their
bent poles are uniformly interspaced about the circle through which the armatures
revolve. The poles in this case are alternately of opposite signs, the coils being
connected up by an alternative split circuit from the main binding screw H, the
main current thus dividing, first, through the electro magnets F then passing
through the framing C to the brusk K and thence after passing through the
armature circuits (as hereinafter more fully explained), returns by the other
insulated brush K¹ to the other insulated binding screw H¹.
To further distribute the magnetic field between the revolving armatures, polo
pieces may be added to the aforesaid poles between and outside the revolving
armatures.
2nd Side by side with the revolving armatures D D hereinbefore described,
I fix a series of square or other polygonal frames F F F, Figures 3 and 4, of
electro field magnets, in each of which are provided 4 pole pieces G G G, as shown
Figure 3, (or in the case of larger motors as many poles as there are corners to the
polygonal frame,) attached to a central spoked frame L L, the said pole pieces
being forked, as shown in detail at Figure 7, to surround and embrace two or more
revolving arinatures.
Between each of these pole pieces, magnet cores (as shown in detail at figure 8)
are wound with insulated wire, and are dropped into slots in the said pole pieces,
as shown in place at FF F, Figure 3. In the arrangement shown, three sets of field
magnet rings, F F F, (Figure 4) are used, with two armature rings D D revolving
between them. The said field electro magnets F F F are connected up by
alternative shunt circuits from the binding screw H, so that they produce alternate
north and south poles between cach pair of electro magnets, the current proceeding
through the frame to one of the brushes as hereinbefore described for the other
motor at figure 1, and after passing through the armature rings, returning by the
other insulated brush to the other insulated main circuit binding screw H¹. The
longitudinal pole pieces G G, Figure 4, serve to bind the field electro magnets F F
in their proper place, and the pole pieces are secured to the end frames B B.
Figure 5 shows diagrammatically the course of the currents through the electro
magnets, and the armatures. The current entering through one brush K, and
through the bar of the commutator M, is distributed in two alternative circuits a, b,
which are again each split up into two alternative circuits c, d, and e, f, respectively.
These divided currents are led, one, d, around an electro magnet on the nearer
armature ring, and the other, c, around an electro magnet in the farther adjacent
armature. The current d after having traversed the first armature, passes round
an electro magnet upon the farther armature, and thence back to the other
collecting brush K¹. The divided current c after traversing the magnet on the
farther armature, returns and passes round an electro magnet on the nearer
armature. The two electro magnets on the nearer armature traversed by the
currents c, d, respectively, generate a pole of like magnetism between them at E¹.
The current c after traversing the second armature electro magnet passes out also
by the brusk K. The branch current b thus provides for the electro magnetisations
of 4 out of the 8 coils on the double combined armature. The other branch
current, a, divided into the alternative currents e, f, if similarly traced, provide for
the magnetisations of the other 4 coils of the combined armature.
It will be seen from this diagram, that as the armatures, and the commutator
therewith, rotate, under the fixed brushes K K', the polarities of the armature

page_text: poles E E are caused to reverse, as they pass through and between the field
inagnetic poles G G, and as they become satisfied.
The magnetism of the fixed electro magnets does not change, and is produced
either by a series or shunt circuit from the main current, supplying the electricity
to the motor as already described in reference to Figures 1 and 3.
The contact brushes K K¹ are mounted on a frame N rotating through a
considerable angle upon its axis, one of the brushes K¹ being insulated thereon.
By the rotation of the brush frame the "lead" of the brushes may be adjusted at
will, or the rotation of the notor may be thereby reversed.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is
1st In an electro motor, the construction of the field magnets whether arcs or
chords of circles with poles forked, so as to embrace and surround the revolving
armatures, and mounted and electrically connected, substantially as described.
2nd In an electro motor the construction of the armatures with the poles of two
or more adjacent armatures upon the same shaft interspaced and connected up
through a single commutator and a pair of brushes, substantially as described.
3rd The general construction of an electro motor consisting of two or more
inter-pole-spaced armatures upon the saine shaft, revolving between the forked
poles of fixed electro magnets, all connected up, substantially as described.
Dated this 9th day of January 1885.
FELL & WILDING,
Agents for the Applicant,