IMPROVEMENTS IN ELECTRO-DYNAMIC MACHINES
Year: 1884

page_text: I, HERBERT JOHN ALLISON, of the firm of Allison Brothers, Patent Agents,
Chancery Lane, London, do hereby declare the nature of said Invention for
"IMPROVEMENTS IN ELECTRO-DYNAMIC MACHINES" to be as follows:—
This Invention relates to an improvement in electro-dynamic machines, the
object of which is first, to provide an armature the core of which is formed of a
series of parallel iron wire rings each of which is wound in U shaped strips and
suspended upon tie-rods, and at intervals apart from each other, which tie-rods are
secured to disks or hubs, which are rigidly secured upon a revolving shaft, and
being further provided with a dia-magnetic core, which is preferably made of a
series of wooden disks lying within the core rings, and secured to the shaft between
the hubs to which the tie-rods are attached.
Another feature of my Invention consists in ventilating the iron core rings
which are overlapped by a series of longitudinal transverse wire coils, wound over
the core rings and dia-magnetic core of the armature, the ends of which transverse
coils are enclosed by perforated metallic disks or drums, leaving a space between
the disks and the transverse coils for circulation of air currents, which air space
has connection with the interior surfaces of the core coils from which it escapes
radially out through the spaces between these core coils, thereby effecting a
thorough ventilation of the armature coils, which prevents the heating of the same
in operation
Another part of this Invention relates to the mode of constructing the commutator,
which is mounted upon the armature shaft.
It consists in providing a series of commutators arranged parallel with each
other upon the shaft, each of which is formed of two semi-circular rings, which are
gained or notched each side of their opposite ends, which gains or notches are
filled with a transverse metallic bridge or plate, the ends of which are arcs of a
circle, and form a portion of the commutator surfaces.
Each of these commutators is connected to an individual armature coil, one pole
being connected to one section of the commutator ring, and the opposite pole to the
opposite section of said commutator, there being as many commutators as there
Pine 31

page_text: are coils wound upon the armature, and these commutators are arranged in
alternating series. In connection with these commutators are arranged a duplex
series of brushes.
The object of this part of the Invention is to shunt the current of each coil
through the transverse circuit radially through the shaft, a short period of time
before the coil arrives at each of the reversing points, and continuing it in shunt
circuit for a short period after the reversal, so as to lessen the resistance due to the
reversals of the coils.
Another feature of Invention consists in a serial circuit connection of the
commutator and series of brushes operating thereon so that the current to line from
each of the coils passes through the series of brushes and coils, except during the
operation of the reversal of a coil, the currents are shunted through the transverse
metallic bridge, instead of passing through the coil at reversal, the object being to
maintain a continuous closed circuit at all times, for all of the coils of the
armature by employing a shunt circuit for each of the coils, at, and during the
periods of reversal, or while it is developing the minimum amount of current.
The series of wooden disks are pierced with axial holes, and rigidly secured to
the armature and commutator shaft. Supporting disks are rigidly secured upon
this shaft and to the core sections or wooden disks just mentioned. These disks
are provided with a series of ears, which are pierced with holes for securing a
circular series of tie-rods. In order to more substantially connect the armature
and its coils to the shaft, I provide metallic plates which are secured to the disks.
They are connected to the core by screw bolts. An inwardly projecting hub or
sleeve forms suitable means for securing the disks and core upon the shaft.
In order to produce an effective core with the least amount of metal, I form the
core of a series of wire rings, each of which is formed of an endless coil of fine
twire, wound in spool form, and supported in U shaped bracket loops which are
preferably made of metal, and pierced with holes, through which holes the tie-rods
are passed, so as to string several coils upon the tie-rods. These tie-rods are
preferably made of dia-magnetic material, but the rings should be insulated
thereon if made of metal. Between each of these wire coils is a space, which is
formed by means of rubber or other suitable washers for separating the coils.
Between the inner periphery of these series of cuils and the wooden core, I provide
a series of air spaces radially under the loops and which are formed by grooving
out the cores. Any number of these air spaces may be employed, and they may
be formed to occupy a larger segmental circumference of the core.
Connecting with each one of these air spaces 1 provide air conduits which are
pierced through the supporting disks, and connect with the, spaces between the
end of the coils and other disks. The transverse longitudinal coils are wound
around outside of the core coils. Between each of the coils are spaces through
which air passes to enter the conduits. Metallic disks enclose the outer ends of
the armature and air spaces between them, and the transverse longitudinal coils.
An orifice is pierced in last named disk which is larger than the armature and
commutator shaft, which passes through it, so as to allow the air to enter freely
around the shaft and be forced by the revolution of the armature through the
spaces and conduits into the spaces under the core coils, from which it is forced
radially outwardly through the spaces between the core coils. The rapid revolution
of the armature causes the air to be forced rapidly after the manner of a com-
pression blower, around through the end coils and out through the air spaces above
described, keeping the entire coils cool, and carrying off heat which would otherwise
be accumulated by the revolution of the armature between the field magnets. The
commutator is constructed as follows: A series of segmental rings are cast with
notches or gains. Two of these sections form the principal portion of a single
commutator. A metallic disk is pierced with a hole. It is larger in diameter than
the shaft which passes loosely through it. Segmental tenons are made at their
ends to form segments to fit and lie between the sections of the commutator rings,
and occupying considerable space each side of the inner ends of said section. In

page_text: practice these sections and segments are insulated from each other, and the spaces
between the segment branches, sectional rings, and the space between the rings
and the shaft which passes through it, are filled with insulating material, so as to
prevent a current passing from the commutator to the shaft.
Tie-bolts are employed for connecting the series of commutators together, and
also form metallic connection of each section with its individual armature coil.
Metallic ears are placed between the bolts and the faces of the rings, so that
when the wire is connected to one of these bolts, metallic connection with the ring
is secured through these ears. There is a pair of bolts for each commutator section.
Thus, bolts pass through all of the sections. But there being ears only at one end,
the bolts will connect currents only to the sections which abut these ears.
Bolts pass through three of the series of commutators having one set of ears,
and connecting with that next in series. Likewise other bolts pass through only
two of the series, and again other bolts pass through only one.
A duplex series of brushes are employed, each of which is in contact with a
single section of the commutator. One brush is placed opposite. the other, so as to
bear upon the opposite section of the same commutator, so that as the sections are
in contact with the latter brush, the opposite segment will be in contact with the
first brush, which will form a shunt circuit connection radially through the bridge,
so that the ccil connected with this commutator will be short circuited by means
of terminal ends which are connected with one set of sections, being also in circuit
with the segment, by reason of the brushes being in contact with the notched
segment of the ring, at the same time it is in contact with the segment of the
branch circuit.
These several brushes are connected in series, a wire connecting the first brush
which is, say, of negative polarity, with the positive brush of the next in series,
and the second brush is in like manner connected with the third brush of the
opposite polarity, and so on, there being as many commutators and brushes as
there are coils wound upon the armature, which may be varied in number at
pleasure.
This serial mode of connection forms a continuous circuit through the brushes
from the commutator to line by wires, and this mode of constructing the com-
mutator coils of the core in continuous closed circuit, but shunts each coil through
a transverse branch and continuing it until after the period of reversal without
cutting it out of circuit, thereby avoiding a great amount of resistance, usually
obtained in the reversal of the armature coils.

page_text: I, HERBERT JOIN ALLISON, of the firm of Allison Brothers, Patent Agents,
Chancery Lane, London, do hereby declare the nature of my Invention for
"IMPROVEMENTS IN ELECTRO-DYNAMIC MACHINES" and in what manner the same
is to be performed, to be particularly described and ascertained in and by the
following statement:-
This Invention relates to an improvement in electro-dynamic machines, the
object of which is-first, to provide an armature the core of which is formed of a
series of parallel iron wire rings each of which is wound in U shaped strips and
suspended upon tic-rods, and at intervals apart from each other, which tie-rods are
secured to disks or hubs, which are rigidly secured upon a revolving shaft, and
being further provided with a dia-magnetic core, which is preferably made of a
series of wooden disks lying within the core rings, and secured to the shaft between
the hubs to which the tie-rods are attached.
Another feature of my Invention consists in ventilating the iron core rings which
are overlapped by a series of longitudinal transverse wire coils, wound over the
core rings and dia-magnetic core of the armature, the ends of which transverse coils
are enclosed by perforated metallic disks or drums, leaving a space between the disks
and the transverse coils for circulation of air currents, which air space has
connection with the interior surfaces of the core coils from which it escapes radially
out through the spaces between these core coils, thereby effecting a thorough venti-
lation of the armature coils, which prevents the heating of the same in operation.
Another part of this Invention relates to the mode of constructing the
commutator, which is mounted upon the armature shaft. It consists in providing
a series of comniutators arranged parallel with each other upon the shaft, each of
which is formed of two semi-circular rings, which are gained or notched each side
of their opposite ends, which gains or notches are filled with a transverse metallic
bridge or plate, the ends of which are arcs of a circle, and form a portion of the
commutator surfaces.
Each of these commutators is connected to an individual armature coil, one pole
being connected to one section of the commutator ring, and the opposite pole to the
opposite section of said commutator, there being as many commutators as there are
coils wound upon the armature, and these commutators are arranged in alternating
series. In connection with these commutators are arranged a duplex series of
brushes.
The object of this part of the Invention is to shunt the current of each coil
through the transverse circuit radially through the shaft, a short period of time
before the coil arrives at each of the reversing points, and continuing it in shunt
circuit for a short period after the reversal, so as to lessen the resistance due to the
reversals of the coils.
Another feature of Invention consists in a serial circuit connection of the
commutator and series of brushes operating thereon, so that the current to linc
from each of the coils passes through the series of brushes and coils, except during
the operation of the reversal of a coil, the currents are shunted through the
transverse metallic bridge, instead of passing through the coil at reversal, the object
being to maintain a continuous closed circuit at all times, for all of the coils of
the armature by employing a shunt circuit for each of the coils, at and during the
periods of reversal, or while it is developing the minimum amount of current.
The several features of the Invention will be more fully explained in the
description of the accompanying Drawings.

page_text: In order that the said Invention of improvements in dynamo-electric machines
and commutators may be fully understood, they are hereinafter fully described by
the several Figures on the Sheets of Drawing, which are hereto annexed, containing
letters of reference to designate the parts, which are also explained in the following
description:-
Figure 1-is a longitudinal sectional view of the armature shaft and coils.
Figure 2-an end elevation of the air drum or disks. Figure 3-an enlarged
sectional view of the air passages leading from the exterior to the interior of the
coils. Figure 4-is an end elevation of the disks which support the core coils.
Figure 5 is a section on line x, x, Fig. 1. Figure 6-is an end elevation of the
armature shown in Figure 1, with the enclosing disk removed.
Figure, 7-is a perspective view of the commutator. Figure 8-is a top plan
view of the commutator. Figures 9 and 10 detail views of the parts. Figure 11-
a plan view of the commutator with the series of collecting brushes arranged
thereon. Figure 12-represents a plan view of the commutator, and Figure 13-a
sectional elevation of the same.
A represents the armature and commutator shaft. B represents a series of
wooden disks, pierced with axial holes, and rigidly secured to the armature
sleeve A¹ and shaft A.
C represents supporting disks which are rigidly secured upon this shaft A, and
to the core sections B, B.
These disks are shown in plan Fig. 4. They are provided with a series of ears c,
which are pierced with holes for securing a circular series of tie-rods D.
In order to more substantially connect the armature and its coils to the shaft,
I provide metallic plates E which are secured to the disks. They are connected to
the core B by screw-bolts d. e represents an inwardly projecting hub or sleeve
which forms suitable means for securing the disks and core upon the shaft A.
In order to produce an effective core with the least amount of metal, I form the
core of a series of wire rings F, each of which is formed of an endless coil of fine
wire, wound in spool form, and supported in U shaped bracket loops f, which are
preferably made of metal, and pierced with holes, as shown in Figure 5, through
which holes the tie-rods D are passed, so as to string several coils upon the tie-rods.
These tie-rods are preferably made of dia-magnetic material, but the rings should
be insulated thereon, if made of metal. Between each of these wire coils F is a
space, which is formed by means of rubber or other suitable washers for
separating the coils. Between the inner periphery of these series of coils and the
wooden core B, I provide a series of air-spaces G, which are shown in section Fig. 5
as radially under the loops f and which are formed by grooving out the cores B.
Any number of these air-spaces may be employed, and they may be formed to
occupy a larger segmental circumference of the core B. Connecting with each one
of these air-spaces G I provide air-conduits H, H¹, which are pierced through the
supporting disks C, and connect with the spaces between the end of the coils and
the disks b. I represents the transverse longitudinal coils wound around outside
of the core coils D as indicated in section, Figs. 1 and 5, and in plan, Fig. 6.
Between each of the coils are spaces I' through which air passes to enter the
conduits H, H¹.
b represents metallic disks which enclose the outer ends of the armature, and
form air-spaces between them and the coils I.
K represents orifices pierced in disks b which are larger than the shaft A which
passes through it, so as to allow the air to enter freely around the shaft and be
forced by the revolution of the armature through the spaces I' and conduits H, H',
into the spaces G under the core coils, from which it is forced radially outwardly
through the spaces g between the core coils D. The rapid revolution of the
armature causes the air to be forced rapidly after the manner of a compression
blower, around through the end coils and out through the air spaces above
described, keeping the entire coils cool, and carrying off heat which would-

page_text: otherwise be accumulated by the revolution of the armature between the field
magnets. The commutator is constructed as follows:-.
A series of segmental rings i are cast with notches or gains has shown in Figs. 7
and 10. Two of these sections form the principal portion of a single commutator.
L represents a metallic plate pierced with a hole 2. It is larger in diameter
than the shaft A which passes loosely through it. m represents segmental tenons
which are made at their ends to form segments to fit and lie between the
sections ¹,, of the commutator rings, and occupying considerable space each side
of the inner ends of said section. In practice these sections ¹, ¹, and segments m
are insulated from each other, and the spaces between the segment branches L,
sectional rings i, and the space between the rings L' and the shaft A which passes
through it, are filled with insulating material, so as to prevent a current passing
from the commutator to the shaft.
1, 2, 3, 4, represent the bolts for connecting the series of commutators together,
and also form metallic connection of each section with the individual armature
coil I.
j represents metallic ears placed between the bolts and the faces of the rings,
so that when the wire is connected to one of these bolts, metallic connection with
the ring is secured through these ears. There is a pair of bolts for each
commutator ring i.
Thus, bolts 1 and 1 are represented as passing through all of the sections. But
there being ears j only at one end, the bolts will connect currents only to the
sections which abut such ears. Bolts 2 pass through three of the series of
commutators having one set of ears, and connecting with that next in series.
Likewise bolts 3 pass through only two of the series, and bolts 4 pass through
only one.
M, M³, represent a duplex series of brushes, each of which is in contact with a
single section of the commutator. Brush M is placed opposite brush M¹, so as to
bear upon the opposite section of the same commutator, so that as the sections '
are in contact with brush M¹, the opposite segment will be in contact with the
brush M, which will form a shunt circuit connection radially through the bridge L,
so that the coil connected with this commutator will be short circuited by means
of terminal ends which are connected with one set of sections i¹ and i', being also
in circuit with the segment 1, by reason of the brushes M. and M¹ being in contact
with the notched segment of the ring i, at the same time it is in contact with the
segment L of the branch circuit.
In Figure 11 these several brushes are shown as connected in series, wire 9
connecting the first brush M which is, say, of negative polarity, with the positive
brush M of the next in series. And the second brush M1 is in like manner
connected with the third brush M of the opposite polarity, and so on, there being as
many commutators and brushes M and M₁ as there are coils wound upon the
armature, which may be varied in number at pleasure.
This serial mode of connection forms a continuous circuit through the brushes
from the commutator to line, which are represented by the wires P, Q, and this
mode of constructing the commutator coils of the core in continuous closed circuit,
but shunts each coil through a transverse branch or bridge L, and continuing
it until after the period of reversal without cutting it out of circuit, thereby
avoiding a great amount of resistance, usually obtained in the reversal of the
armature coils.
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 -
1. An armature composed of a series of radial rings D having air-spaces g,
in combination with air-spaces G and H for conducting currents of air into the
interior of the armature, and discharging it radially outward, substantially as
herein set forth

page_text: 2. In combination with the armature of the dynamo-elec'r.c machine, the disks b
covering the ends of the armature, and provided with air-entering spaces K, at or
near the axes of the shaft, for forcing air between the spaces of the coils into the
interior spaces H and G, substantially as herein set forth.
3. A dynamo-electric machine provided with disks benclosing the ends of the
armature, having air orifices K at or near the axes, and air-passages E, G, for
carrying the air through the armature coils, and discharging it radially outward
through spaces g, substantially as herein set forth.
4. An armature composed of the dia-magnetic core B having air-spaces G
arranged longitudinally along the periphery of the core B, in combination with
the radial rings D, having air-spaces g, and the disks benclosing the ends of
coils I, with the air orifices K near the axes A, substantially as herein set forth.
5. In combination with the armature of a dynamo-electric generator, a
commutator composed of duplex segments of rings upon diametrically opposite sides
of the shaft, insulated from each other at the two neutral lines, and having a
segmental shunt branch L forming a portion of the commutator surface on either
side of the two neutral points, so as to shunt the current in the coil connected
thereto before, and continuing until after passing the neutral line, and forming a
transverse branch circuit through the commutator without cutting the coil out of
circuit, substantially as herein set forth.
6. In combination with an armature having a series of induction coils, a series of
duplex segmental commutators i, i, each provided with segmental shunt branch L
forming a part of the commutator surface on each side of the neutral lines, and in
juxtaposition with each end of both sections a, i, the terminals of each coil being
connected respectively with sections and in series, so that the terminals of
each coil are brought into shunt connection with the branch before, and
continuing until after it passes the neutral points, thus shunting the current in said
coil, the branch 7 forming a shunt for the remaining coils during said period of
reversals, maintaining at all times the several coils in continuous closed circuit,
substantially as herein set forth.
7. In combination with an armature having a series of induction coils, the
terminals of which are severally connected to commutator sections i, i, having the
shunt branch connections Ll and two series of brushes M, M¹, the whole connected
in serial circuit, so that the terminals of each coil are brought into metallic
connection with the branches L before, and continuing until after passing the
neutral lines, and the current of remaining coils are shunted through the same
branch during said period, thereby maintaining all of the coils at all times in
continuous closed circuit, substantially as herein set forth.
Dated this 19th day of June 1884.