IMPROVEMENTS IN ELECTRIC GENERATORS AND KOMADA PROVISIONAL SPECIFICATION
Year: 1883

page_text: LETTERS PATENT to William Morris Mordey of Putney, in the County of
Surrey for an Invention of IMPROVEMENTS IN ELECTRIC GENERATORS AND
KOMADA
PROVISIONAL SPECIFICATION left by the said William Morris Mordey at
the Office of the Commissioners of Patents on the 24th January 1883.
WILLIAM MORRIS MORDEY of Putney in the County of Surrey, IMPROVE
MENTS IN ELECTRIC GENERATORS AND MOTORS
"
**
My invention relates to improvements in dynamo-eléctric generators and motors,
and refers to those machines wherein the armature wire or other conductor is
continuous and endless, such armatures being principally of three classes; viz;
annular or ring, drum, and cylinder armatures. In arinatures of these classes the
metallic wires, bars, strips, ribbons, or their equivalents are electrically connected
throughout their length; being at suitable intervals connected to segments, plates,
or divisions of the commutator, the number of such segments corresponding to the
number of intervals at which the conductor is led off from the armature.
My invention relates to dynamo electric machines in which such armatures are
caused to revolve in magnetic fields produced by more than two, or by any
multiple of two magnetic poles. In machines of this type as heretofore constructed
with multiple poles the current is usually collected from the commutator by
separate brushes, springs, rollers, or their equivalents, pressing upon parts of the
commutator corresponding to the "neutral points" of the magnetic field, such
"neutral points" being equal in number to the number of inagnetic poles employe.l.
Having to connect, support, set, adjust, and keep in order a number of individual
brushes has hitherto been a source of great inconvenience and trouble.
When the magnetic poles of such a machine are equidistant from one another
the coils, bars, strips, or other conductors of the armature at equidistant points
from poles of similar sign are equipotential when the notion of such coils or their
equivalents is similar in direction with regard to such similar poles.
Now the object of my invention is to simplify the collection of the current by
connecting the equipotential points of the armature with one another by means of
conductors such as metallic wires, plates, rings, bars, or their equivalents; such

page_text: connections being made either between the conductors which connect the armature
and the commutator, or between the commutator segments or plates themselves in
the manner described below: thus as the commutator segments of all the coils
which are in the same phase of excitation, and are therefore equipotential, are
connected, only one pair of brushes is required to collect the current. For instance,
in an annular armature revolving in the magnetic fields produced by four equidistant
poles, alternately N and S, the wire or other conductor consisting of, say, 48 coils
or equivalent divisions connected together in the usual way, I also connect the
terminal or joining wires of the various coils or divisions, or the corresponding
commutator segments, in the following order :-1, 25; 2, 20; 3, 27; 4, 28; 5, 29;
6, 30; 7, 31; 8, 32; 9, 33; 10, 34; 11, 35; 12, 36; 13, 37; 14, 38; 15, 39;
16, 40; 17, 41; 18, 42; 19, 43; 20, 44; 21, 45; 22, 46; 23, 47; 24, 48.
With this arrangement two brushes collect the current, in place of four.
Again, with a similar armature to the above, revolving in the magnetic fields
produced by six magnetic poles, I connect the terminal or joining wires, or the
corresponding commutator segments, in the following order :-1, 17, 33; 2, 18, 34;
3, 19, 35; 4, 20, 36; 5, 21, 37; 6, 22, 38; 7, 23, 39; 8, 24, 40; 9, 25, 41;
10, 26, 42; 11, 27, 43; 12, 28, 44; 13, 29, 45; 14, 30, 46; 15, 31, 47;
16, 32, 48.
With this arrangement two brushes are used to collect the current in place
of six.
Again with a similar armature revolving in the magnetic fields produced by
eight equidistant poles, and having, as above, forty eight coils or divisions, I
connect the terminal or joining wires or commutator segments of the various coils
or divisions of the armature conductor in the following order :-1, 13, 25, 37;
2, 14, 26, 38; 3, 15, 27, 39; 4, 16, 28, 40; 5, 17, 29, 41; 6, 18, 30, 42;
7, 19, 31, 43; 8, 20, 32, 44; 9, 21, 33, 45; 10, 22, 34, 46; 11, 23, 35, 47;
12, 24, 36, 48; which enables me to collect the current by means of two brushes
instead of eight. This will be understood from the following explanation:-
In this armature, revolving in these magnetic fields, there are 8 "neutral points,"
or points where the generation of current changes in direction, equidistant from one
another, and alternately positive and negative; these points, subject to the
displacement due to the phenomenon of "dissymmetry of commutation," being
midway between the poles. Thus, if the localities of the armaturo conductor
corresponding to commutator segments 1, 13, 25, 37 are in the four positive
"neutral points," 7, 19, 31, 43 will occupy the four negative "neutral points"
Now, as segments, 1, 13, 25, 37 are connected, a brush pressing on any one of them
will collect the current from these four equipotential positive "neutral points;"
and as segments, 7, 19, 31, 43 are connected a second brush pressing on any one of
them will collect the current from these four equipotential negative "neutral
points." The rotation of the armature will then bring 2, 14, 26, 38 into the four
positive "neutral points," and 8, 20, 32, 44 into the four negative "neutral points"
and so on.
Those coils which are not in the positions of neutrality being connected
together in like order, and the portions of the magnetic fields which they are
traversing being similar, they will not tend to neutralise one another, or to weaken
the general effect, as the coils of each set are equipotential.
The number of brushes necessary to collect the current with a still greater
number of magnetic poles is thus always two.
I do not, however, limit myself to one pair of brushes in all cases, as, for instance,
if sixteen poles are employed, four brushes may be used, the armature being so
joined up that four of the eight equipotential positive "neutral points" are con-
nected, the current being collected from them by a brush pressing on any one of
the corresponding segments; the other four positive "neutral points" being also
joined together, and the current collected by a second brush pressing on any one
of the four corresponding segments. The connection of all the coils, or the like,
being in this order two more brushes are arranged to collect the current from the
eight negative "neutral points" which are joined in two groups of four each.

page_text: In carrying out my invention where I desire to join the commutator segments
themselves I make the necessary cross connections in the interior of the com-
mutator, which is constructed hollow for this purpose. Thus, in the case of the
employment of four field magnets, where the diametrically opposite segments
require to be electrically connected, I build the commutator with cross connecting
bars arranged throughout its length so that there is no contact between the
various bars. In the case of the employment of eight field-magnets I use + or
star-shaped internal commutator connections, arranged throughout the length of
the commutator as in the foregoing instance, so that they are clear of one another.
A further object of this invention is the reduction of the number of connections
required to be brought to the commutator; so that in the case of the commutator
being placed outside the bearing of the machine, the difficulty-mechanical and
electrical of bringing a large number of wires or other conductors through a hollow
shaft, or through a sleeve-bearing is considerably reduced. Thus, in the three
instances above described, where machines with four, six, and eight field-magnets
respectively are employed; and where, according to the method hitherto in use,
forty eight wires or other conductors are required to be brought from the above-
described armature to the commutator; I reduce this number to twenty four in
the case of four magnets, sixteen in the case of six magnets, and twelve in the
case of eight magnets. Thus in the latter case it will be seen from the description
of the connections that the junctions of the various coils or divisions of the
armature conductor are connected in order, 1, 13, 25, 37 etc By making the
connections at the armature, or between the armature and bearing; and having
the commutator segments connected interiorly by + pieces, one only of these four
conductors is continued to the commutator, the other three being only made
long enough for the necessary connection to the ring or other conductor used to
unite the four. In like manner one of every four wires or other conductors from
the armature is brought to the commutator, the remaining three being cut off in
each case. Every fourth segment only of the commutator is thus attached directly
to a conductor from the armature. It will be seen that the number of connections
necessary to be brought to the commutator will be found for any given number of
poles (such number being a multiple of 2-) by dividing the total number of
armature coils or divisions by half the number of field-magnets. Also that the
armature coils or divisions should be a multiple of the field magnets.
By a magnetic pole, or field-magnet, I would be understood to mean the mass
or masses which produce a common polar effect Thus, two polar projections of
like sign presented respectively to the two flat faces of one portion of a flat ring
armature I consider to be practically one pole; although they may be two
separate electro or permanent magnets. Also I consider as one pole the case of
the presentation to the inner surface of an armature of a magnetic pole similar in
sign to that which is presented to the outer portion of the armature; as the two
poles are one in the effect they produce upon the portion of the armature passing
between them, and on the armature as a whole.
By one brush or its equivalent I include the case of two or more brushes, springs,
rollers, or other suitable means, used together-as, for instance, side by side,-to
collect the current from any given portion of a commutator.
In this specification dynamo electric machines are described as generators. I
wish it, however, to be understood that the improvements refer equally to dynamo
electric machines as motors; and that by dynamo electric machines I mean not
only those wherein the accumulative or self-exciting principle is employed, but
also separately-excited, and so-called magneto-electric machines; as well as those
where a combination of these principles is made use of.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said William Morris Mordey in the Great Seal Patent Office on the
24th July 1883.
WILLIAM MORRIS MORDEY of Putney in the County of Surrey "IMPROVE-
MENTS IN ELECTRIC GENERATORS AND MOTORS
"
My invention relates to improvements in dynamo electric generators and motors,
and refers to those machines wherein the armature wire or other other conductor is
continuous and endless, such armatures being principally of three classes: viz
annular or ring, drum and cylinder armatures. In armatures of these classes the
metallic wires, bars, strips ribbons, or their equivalents are electrically connected
throughout their length; being at suitable intervals connected to segments, plates
or divisions of the commutator, the number of such segments corresponding to the
number of intervals at which the conductor is led off from the armature.
My invention relates to dynamo electric machines in which such armatures are
caused to revolve in magnetic fields produced by more than two or by any multiple
of two magnetic poles.
In machines of this type as heretofore constructed with multiple poles the current
is usually collected from the commutators by separate brushes, springs, rollers or
their equivalents, pressing upon parts of the commutator corresponding to the
"neutral points" of the magnetic field, such "neutral points "being equal in number
to the number of magnetic poles employed.
Having to connect, support, set, adjust and keep in order a number of
individual brushes has hitherto been a source of great inconvenience and trouble.
When the magnetic poles of such a machine are equidistant from one another
the coils, bars, strips or other conductors of the armature at equidistant points
from poles of similar sign are equipotential when the motion of such coils or their
equivalents is similar in direction with regard to such similar poles.
Now the object of my invention is to simplify the collection of the current by
connecting the equipotential points of the armature with one another by means of
conductors such as metallic wires, plates, rings, bars or their equivalents; such
connections being made either between the conductors which connect the armature
and the commutator or between the commutator segments or plates themselves in
the manner described below: thus as the commutator segments of all the coils
which are in the same phase of excitation, and are therefore equipotential are
connected, only one pair of brushes is required to collect the current.
Figures 1 to 3 illustrate diagrammatically the application of one part of my
invention to an iron ring armature or cylinder armature wound by a continuous
coil or by a number of separate coils electrically connected throughout their length
in what is known as Pacinotti winding, the conductor being connected at
suitable intervals to segments or plates of the collector or commutator C. In the
Figures 48 such coils or divisions and segments are shewn. Figure 1 illustrates
the connections for an armature revolving in the magnetic fields produced by four
equidistant poles, alternately N. and S. The 48 junctions of the coils, or points at
which the continuous coil is led to the commutator, are connected together in the
usual way, but diametrically opposite junctions are also connected together in the
following order-1, 25; 2, 26; 3, 27; 4, 28; 5, 29; 6, 30; 7, 31; 8, 32; 9, 33;
10, 34; 11, 35; 12, 36; 13, 37; 14, 38; 15, 39; 16, 40; 17, 41; 18, 42; 19, 43;
20, 44; 21, 45; 22, 46; 23, 47; 24, 48; This is conveniently done in the process
of winding, as follows:- the two wires at each junction are connected in the

page_text: customary manner, one of the wires is then carried to the proper segment of the
commutator and the other is made to meet a similar end from a diametrically
opposite junction these two wires being soldered together. In Figure 1, for the
sake of clearness six out of the twenty four connections only are shewn.
Figure 2 illustrates the connections for armatures similar to those above
mentioned, but intended to revolve in the magnetic fields produced by six magnetic
poles. The junctions of the coils are in the following order :-1, 17, 33; 2, 18, 34;
3, 19, 35; 4, 20, 36; 5, 21, 37; 6, 22, 38; 7, 23, 39; 8, 24, 40; 9, 25, 41;
10, 26, 42; 11, 27, 43; 12, 28, 44; 13, 29, 45; 14, 30, 46; 15, 31, 47; 16, 32, 48;
In Figure 2, of the sixteen connections five only are shewn.
Figure 3 illustrates the connections for an armature of either of the above types
intended to revolve in the magnetic fields produced by eight equidistant poles, and
having, as above, 48 coils or divisions. I connect the terminal or joining wires of
the various coils or divisions of the armature conductor in the following order:
1, 13, 25, 37; 2, 14, 26, 38; 3, 15, 27, 39; 4, 16, 28, 40; 5, 17, 29, 41; 6, 18, 30, 42;
7, 19, 31, 43; 8, 20, 32, 44; 9, 21, 33, 45; 10, 22, 34, 46; 11, 23, 35, 47; 12, 24,
36, 48, leading also a connection from each junction to the corresponding commu-
tator segment. In Figure 3 only four of the twelve connections are shewn. Instead
of using the armature wires themselves to make the connections, sometimes I
employ rings or strips of copper attached to the junctions substantially in the same
way. In cases where the armature is already wound and mounted, this enables
the alteration to be made easily and quickly. By the above described means I am
enabled to collect the current in each case by employing two brushes only. This
will be understood from the following explanation.
In an armature revolving in magnetic fields produced by 8 poles there are
8 "neutral points," or points where the generation of current changes in direction,
equidistant from one another, and alternatly positive and negative; these points,
subject to the displacement due to the phenomenon of "dissymmetry of commu-
tation," being midway between the poles. Thus, if the localities of the armature
conductor corresponding to commutator segments, 1, 13, 25, 37; are in the four
positive "neutral points" 7, 19, 31, 43 will occupy the four negative "neutral
points." Now as segments 1, 13, 25, 37 are connected a brush pressing on any
one of them will collect the current from these four equipotential positive "neutral
points;" and as segments 7, 19, 31, 43 are connected, a second brush pressing on
any one of them will collect the current from these four equipotential negative
"neutral points." The rotation of the armature will then bring 2, 14, 20, 38 into
the four positive "neutral points, and 8, 20, 32, 44 into the four negative "neutral
points" and so on. Those coils which are not in the positions of neutrality being
connected together in like order, and the portions of the inagnetic fields which they
are traversing being similar; they will not tend to neutralise one another, or to
weaken the general effect, as the coils of each set are equipotential.
The number of brushes necessary to collect the current with a still greater
number of magnetic poles is thus always two.
"
I do not, however, limit myself to one pair of brushes in all cases as, for
instance, if sixteen poles are employed, four brushes may be used, the armature
"neutral points'
being so joined up that four of the eight equipotential positive
are connected, the current being collected from them by a brush pressing on any
one of the corresponding segments, the other four positive "neutral points" being
also joined together, and the current collected by a second brush pressing on any
one of the four corresponding segments. The connection of all the coils, or the
like, being in this order two more brushes are arranged to collect the current from
the eight negative "neutral points" which are joined in two groups of four each.
It will be seen from the foregoing that figures 1, 2 and 3 besides illustrating the
connections of the armatures when revolving in the fields produced by four, six,
and eight magnetic poles respectively, two brushes being used in each case, serve
also as diagrams of the connections for similar armatures when eight, twelve, and
sixteen poles are respectively employed, four brushes being used in each case.

page_text: In carrying out my invention I sometimes make the necessary connections in
the interior of the commutator which is constructed hollow for this purpose.
Thus in the case of the armature referred to in figure 1 where the diametrically
opposite junctions require to be electrically connected, instead of making the
connections as described and shewn by figure 1. I build the commutator with the
diametrically opposite segments respectively connected interiorly by means of bars
arranged throughout its length, so that there is a clear space between the
various bars.
Figures 7 and 8 shew the construction of such a commutator for an armature of
either of the above-mentioned types revolving in the magnetic fields produced by
8 field magnets. Figure 7 is a sectional elevation of the commutator, and figure 8
a section through a, b. The commutator segments are numbered 1 to 48. S is the
shaft on which the armature is mounted, H, H, are the hubs supporting the
commutator, and C, C, C, are the internal cross connections which join the segments
in the order 1, 13, 25, 37; 2, 14, 26, 38; 12, 24, 36, 48. The 48 junctions of the
armature are connected to the corresponding segments, but for reasons which are
explained below only part of these connections are shewn in Figures 7 and 8.
A further object of this invention is the reduction of the number of connections
required to be brought to the commutator so that in the case of the commutator
being placed outside the bearing of the machine, the difficulty mechanical and
electrical of bringing a large number of wires or other conductors through a hollow
shaft, or through a sleeve-bearing is considerably reduced. Thus in the three
instances above described where machines, with four, six and eight field-magnets
respectively are employed, and where according to the method hitherto in use
forty eight wires or other conductors are required to be brought from the above
described armature to the commutator.
As diagrammatically shewn in figures 4, 5 and 6 I reduce this number to 24 in
the case of four magnets (see Figure 4) 10 in the case of six magnets (Figure 5)
and 12 in the case of eight magnets being used (Figure 6). For the sake of
clearness part only of the necessary connections are shewn in these figures.
Figures 7 and 8 illustrate the last named case where eight magnets are
employed. I join the connections of the armature_conductor junctions in the
order 1, 13, 25, 37 etcetera as shewn in Figure 3. In Figure 7, B is a sleeve
bearing through which twelve of the connections only are brought and attached
to the commutator in the manner shewn, or one from each group of four, the
other 36 commutator leads being dispensed with.
It will be seen in Figure 8 that the twelve commutator segments connected
directly by leads from the armature are 1, 5, 10, 14, 18, 22, 24, 27, 31, 35, 40, 44.
It will be seen that the number of connections necessary to be brought to the
commutator will be found for any given number of poles (such number being a
multiple of 2) by dividing the total number of armature coils or divisions by half
the number of field magnets. Also that the armature coils or divisions should be
a multiple of the field magnets.
By a magnetic pole, or field magnet, I would be understood to mean the mass or
masses which produce a common polar effect. Thus two polar projections of like
sign presented respectively to the two flat faces of one portion of a flat ring
armature I consider to be practically one pole; although they may be two separate
electro or permanent magnets. Also I consider as one pole the case of the
presentation to the inner surface of an armature of a magnetic pole similar in sign
to that which is presented to the outer portion of the armature; as the two poles
are one in the effect they produce upon the portion of the armature passing between
them, and on the armature as a whole.
By one brush or its equivalent I include the case of two or more brushes, springs,
rollers, or other suitable means, used together-as, for instance, side by side to
collect the current from any given portion of a commutator.
In this specification dynamo electric machines are described as generators. I
wish it however to be understood, that the improvements refer equally to dynamio

page_text: electric machines as motors; and that by dynamo electric machines I mean not
only those wherein the accumulative or self-exciting principle is employed but also
separately excited, and so called magneto-electric machines; as well as those where
a combination of these principles is made use of.
Having described the nature of my said invention and in what manner it is to
be performed what I claim is―
1. In a dynamo machine in which the armature revolves in a magnetic field or
fields resulting from the influence of four or some greater number of poles being a
multiple of two, arranging as hereinabove described with reference respectively to
Figs. 1, 2 and 3 of the drawings the electrical connections between the terminals of
those coils of the armature that are in a state of equal potential for the purpose set
forth.
2. In a dynamo machine in which the armature revolves in a magnetic field or
fields resulting from the influence of four or some greater number of poles, being a
multiple of two arranging internal electrical connections between those bars or
segments of the commutator that are of equal potential as and for the purposes
hereinbefore described with reference to and illustrated in the drawings
3. In a dynamo machine in which the armature revolves in a magnetic field or
fields, resulting from the influence of four or some greater number of poles, being a
multiple of two; connecting electrically all the terminals of the coils that are in a
state of equal potential; also all the corresponding bars or segments of the com-
mutator; likewise, each set of coils of equal potential to the corresponding set of
bars or segments; substantially as, and for the purpose, described with reference to
and illustrated in Figs 4 to 8 of the drawings.
In Witness whereof I the said William Morris Mordey have hereunto set my
hand and seal this twenty fourth day of July A.D. 1883.
W. M. MORDEY. (L.S.)