IMPROVEMENTS IN ELECTRO-MOTORS
Year: 1883

page_text: LETTERS PATENT to Octavius March, of Hornton Street, in the County of
Middlesex, Engineer, and Frederick Cheeswright, of St Dunstans Buildings, in
the City of London, Gentleman for an Invention of IMPROVEMENTS IN
ELECTRO-MOTORS
PROVISIONAL SPECIFICATION left by the said Octavius March and
Frederick Cheeswright at the Office of the Commissioners of Patents on
the 28th September 1883.
OCTAVIUS MARCH, of Hornton Street, in the County of Middlesex, Engineer,
and FREDERICK CHEESWRIGHT, of St. Dunstan's Buildings, in the City of London,
Gentleman, IMPROVEMENTS IN ELECTRO-MOTORS
"
"
Our invention is designed first to admit of electric currents of low tension and
large quantity being applied for the production of mechanical effect; and secondly,
to utilize such currents in a more continuous manner than has hitherto been the
case
We carry out our invention in the following manner. On the main shaft of the
machine we fix one or more discs, around the peripheries of which we fix a number
of electro magnets parallel to the shaft, and instead of connecting these in series
as is customary, where two or more magnets are used for motors, we connect the
magnets of each disc in one or more multiple arcs, which may be readily varied by
means of any suitable mechanical device, so as to allow of the internal resistance
being altered to suit circumstances, and thereby diminish the resistance of the
circuit to any desired extent. Each set of magnets is arranged to face a corre-
sponding set on a fixed framework surrounding the shaft, and where two discs or
more are used, we fix them on the shaft in such a manner that the magnets of each
disc shall always occupy a position, circumferentially interspaced with those of the
other discs. Alternatively we interspace the magnets of the fixed frames instead
of those of the discs. We then arrange any suitable form of commutator to divert
the current through each set of moving and fixed magnets in succession, at the
points or periods of greatest efficiency. By this means we are able to continually
utilize the current, without any dead points or cut outs, as is generally the case.
We provide a ready means of reversal by mounting the contact brushes on a
pivotted co-radial frame, so that the brushes may be readily moved from one
section to another of the commutator

page_text: in order that our invention may be the better understood, we now proceed to
describe the same with reference to the drawings hereto annexed, and to the letters
and figures marked thereon
Figure 1. is a side elevation of one form of our motor.
Figure 2. is an end view of the same.
Figure 3. is an end view of the commutators therefor.
Figure 4. is a side view of an alternative form of our motor.
Figure 5. is an end view, showing the interspaced arrangement of the double set
of magnets upon one of the plates.
Figure 6. is an end view showing the commutator arrangements, and the radial
position of magnets upon the other plate.
We carry out our Invention in the following manner;—
In the first form of our Machine, Figures 1 and 2, we fix on the main shaft A of
the machine one or more discs B, upon the peripheries of which project a number
of electro magnets C parallel to the shaft, and instead of connecting these in series
as is customary, we connect the magnets of each disc either entirely in parallel arc
or partially in series and parallel arc, conveniently by means of the following
device Surrounding the ring of magnets we fix three bands D. E. F, of which the
centre one E. is of non-conducting material The other two, D and F, on either
side, are of conducting material, insulated from the coils such as brass-We bring
the terminals of each of the coils to two binding screws c, c, upon the said central
strip E, and when it is desired to connect all the electro magnets in parallel arc,
the terminals are carried across to the corresponding binding screws d, f, on the
side strips D. and F, the current being conducted to and away from the electro
magnets by the bands D and F-In the right hand portion of our motor,. Figure 1.,
we show all the electro magnets coupled up, in parallel. arc, and alternatively, as
shown on the left hand side of our motor, Figure 1., we may couple up the terminals
from the binding screws e, c, upon the centre non-conducting band E, from magnet
to magnet in sets of 2, 3, 4, or more in series, as may be desired, each series being
connected up in parallel arc to the bands D and F.-It is obvious that this method
of connection affords the greatest facility for ready change of the internal resistance
of the motor, by coupling up the magnets in partial sets of series to any extent
that may be desired.
a
Each set of magnets C. C. upon the revolving disc B. is arranged to face the
corresponding sets G. G. on a fixed framework H. H. supporting the shaft A.-
If the magnets C. C., as shewn, are placed co-incidently with one another in their
position on the revolving disc B., we interspace the sots of magnets G and G₁ one
to another, so that when any set of inagnets, C and G¹ for instance, have arrived
pole to pole, and are therefore satisfied, the other set of magnets C and G are in
the position of best attraction one to another
Upon the shaft A we arrange the commutators K. K¹, each commutator being
connected up to one of the sets of revolving magnets C. C. respectively.-The

page_text: current for driving the motor is connected in alternative circuit to either of the
two brushes L and M, and therefrom, through whichever commutator is in position
to complete the circuit, to that set of revolving magnets in whole or partial parallel
are which is in the best position for mutual attraction with the fixed magnets; the
current returning through the other brush say L', which completes the circuit
through the conducting bars of the commutator-The current is carried from the
latter brush in parallel arc, whole or partial, through that set of fixed electro
magnets G which are opposite to the other set of moveable electro magnets C.
through which the current may be passing from the same commutator K³, and is
thence returned to earth or a return cable.
The commutator is constructed of alternate conducting bars and insulating
bars, as shown in Section, Figure 3.-When one commutator, say K¹, by its
revolution breaks the circuit, as hereinbofore described, at the moment when the
electro magnets have como into juxta-position and are satisfied, the circuit is
thereby simultaneously diverted and completed through the other commutator
brushes M. M', the circuit being completed through the other set of fixed and
moving electro magnets which are now in the position of mutual maximum.
attraction, but before the previous contact is entirely broken. The driving circuit
is thus never absolutely interrupted, but is only alternately diverted through the
double set of magnets when in their position of maximum efficiency-We are
thereby enabled to utilize the moving force of the current without interruptions,
dead points, or cut outs, as is usually the case.
We alternatively may arrange two or more circular sets of electro magnets upon
one pair of discs, instead of single sets upon each of two or more pairs of discs.
This we show in Figures 4. 5 and 6 In this case on one of the discs we preferably
arrange the magnets of different sets in radial lines from the centre, and on the
other opposite disc we necessarily interspace the circular sets, so that when one is
satisfied and in juxta position with its opposite attracting poles, the other set is in
the position of maximum effect-These sets of electro magnets which are fitted
upon the revolving disc B are conveniently connected up to as many commutators
as there are annular sets similarly as described for our first form of motor-The
current is completed by alternative circuits through two or more sets of brushes,
the circuit always being completed through that set of magnets which is in position
for maximum effect, the others that are satisfied being similarly cut out, without
however absolute stoppage of the current as before described and without creating
a dead point. We conveniently connect up these annular rings of electro magnets
which are upon the revolving disc and upon the fixed disc by three bands
surrounding each set, enabling us to arrange them either all in parallel arc, or
partially in series and parallel arc, as hereinbefore described-Where it may be
found desirable in the case of fixed discs, we may place the three annular rings
upon the back of the disc.
The circuit is completed, as hereinbefore described for our first modification, by
passing through one of the brushes, the commutator bar, the ring of moving electro
magnets, back through the commutator bar, and the second brush, through the
fixed set of electro magnets, which are in the position of maximum effect to the
before mentioned moving electro magnets, and thence to earth or return wire.
We provide a ready means of reversal by mounting the contact brushes on a
pivotted co-radial frame P.so that the brushes may be readily moved from one
section of conducting commutator bars to another.
The herein before described motor need not necessarily be constructed to make
complete rotations, but the essential points of our Invention would be employed in
any multipolar motor which should make only a fraction of a revolution or an
oscillating reeiprocation.
Having now described our Invention and the method of carrying the same into
effect be it known that what we consider novel and claim is ;-
1st In an electro-motor the combination of two or more sets of multipolar
electro-magnets, mutually attracting one another to produce motion, the said

page_text: electro magnets being coupled up entirely in parallel arc or partially in series and
in parallel are, substantially as described.
2nd In a multipolar electro motor, the combination with the electro magnets of
three external circular bands, the centre one non-conducting and the two external
ones conductors, with binding terminals thereon to effect alternative coupling up
either in entire parallel arc or partially in series and in parallel arc, substantially as
described.
3rd In a multipolar electro-motor, the combination of two or more annular sets
of electro-magnets arranged radially upon a single disc, with a similar number of
annular sets of electro magnets interspaced upon a disc in juxta position with the
former sets, substantially as and for the purpose described in reference to
Figures 4. 5 and 6.
4b In a multipolar electro-motor, the combination of any number of annular
sets of electro-magnets mounted and connected as hereinbefore claimed, with a
commutator or commutators and brushes to effect alternate diversions of the
current through alternate sets of electro-magnets without actual break, substantially
as described.
In witness whereof we, the said Octavius March and Frederick Cheeswright,
have hereunto set our hands and seals this twenty-fifth day of March in the year of
our Lord one thousand eight hundred and eighty-four.
Witness:
RICHARD A HOFFMANN
Clerk to Fell & Wilding
23 Rood Lane
Fenchurch Street.
London, E.C.
QUTATUD MARUD
(L.S.)
FREDERICK CHEESWRIGHT (L.S.)