IMPROVEMENTS IN DYNAMO ELECTRIC MACHINES
Year: 1884

page_text: I WILLIAM EDWARD GEDGE of N° 11 Wellington Street, Strand, London, in the
County of Middlesex, Patent Agent do hereby declare the nature of my Invention
for IMPROVEMENTS IN DYNAMO ELECTRIC MACHINES and in what manner the
same is to be performed, to be particularly described and ascertained in and by the
following statement :-
My Invention relates to new and useful improvements made in dynamo electric
machines, and consists in the special construction of parts, in the mode of winding
and connecting the armature and field magnets coils, as herein fully described,
reference being had to the annexed Drawings, forming part of this Specification.
Fig. 1 is a front elevation of the magnetic frame of the dynamo, showing the
construction of its iron parts, also showing sectional cut of the armature core and
coils and of the field magnet coils.
Fig. 2 is a sectional plan view of the dynamo, showing the construction of the
armature core, the winding and connecting of the field and working circuits, with
their respective commutators.
Fig. 3 is a diagram of connections of the armature coils to the respective
commutators.
Fig. 4, is a longitudinal view of parts of the armature coils showing how their
terminals are connected to the commutator sections.
Fig. 5 shows the mode of winding the coils of the armature and how the
terminals are brought out.
Fig. 6 is a diagram of connections of the armature coils.
Fig. 7 is an end view of the armature, showing how it is carried by the flanges G,
upon its shaft X.
Fig. 8 shows a dynamo machine as ready for operation having its lamps in circuit
and also the automatic current regulator to the fields of the dynamo.
Fig. 9 shows the wood face plate w and the ring carrying the brushes J¹,
and I
In the above Figures similar letters indicate like parts.
A, represents the armature and is construoted as follows: two iron rings E, E,
are riveted to the iron bars D, D, etc., the bars being placed on the inside of said
"

page_text: rings parallel with the armature shaft and so distanced as to leave about one
sixteenth inch or more space between each two adjacent bars: when the bars are
all riveted in their place the whole forms a cylinder upon which is now wound a
number of iron rings B, B, placed a certain distance from one another as shown in
Figure 2. Said iron rings are composed or built up of galvanized iron wire and
thus each convolution is magnetically insulated from the others. When all the rings
are complete upon the cylinder a number of iron bars equal to that placed on the
inside of the rings E, E, are now arranged on the outside of the rings B, B, etc., and
properly secured over said rings, diametrically opposite the iron bars on the inside
of the cylinder as shown in Figs. 1 and 2. Over this iron frame or core is now
wound proper insulating material, paper cloth or the like, properly painted with
shellac or other insulating varnish and set to dry; this completes the iron core
upon which the copper conductor is subsequently wound in the manner now to be
described.
The core is now divided up in sections corresponding to the number of iron bars
on the inner and outer side of the cylinder and directly over these bars are wound
the copper conductors forming the circuit around said core; the winding being thus
performed on the inside and outside of the core, and parallel with the axis of
rotation as shown in Figs. 1 and 2. The winding is accomplished in the following
manner; the armature is divided into say 32 sections the inside wire of one
section being connected to the outside of the next section, all around till the core is
entirely covered, then there will be required a commutator with 32 sections, to each
of which the terminals of the corresponding sections or coils in the armature will
be, connected; this is the mode adopted in the "Pacinotti" or "Gramme" armature
windings; however I differ from this mode by using two commutator sections for
each section or division of the wire wound on the armature, so that instead of
using 32 sections on the commutator I use 64. This I accomplish in the following
manner- -When each coil or division is half way wound I pass a loop of wire to
the outside and then continue the winding of the remainder of the wire as before,
as seen in Figure 5, where 1 is the inside terminal, 2 the half way loop or terminal,
and 3 the outside terminal. Figure 6 shows the mode of the winding and
connections to the adjoining sections and to the commutator sections 1, 2, 3, 4, 5.
Figure 4 shows the practical winding and connecting. 1 is the inside terminal,
2 the half way terminal, and 3 the outside terminal connected to the inside
terminal of the next coils etc., etc. Thus is seen that each coil necessitates two
commutator sections instead of one. The advantage I claim for this mode of
winding and connecting is that it is much easier to wind the armature in 32 sections
or divisions than with 64 for the same diameter of drum, and further that thereby
the sparking at the commutator is reduced to almost nothing.
Figure 3 is a diagram of connections, where instead of one circuit, two circuits
are located upon the same armature core eight sections C, C, etc., each section
divided in two as above explained and consequently 16 terminals are all connected
to a commutator J, having a corresponding number of sections. This circuit is set
apart in the armature to energize the field magnets of the machine. The other or
main circuit intended to do the outside work has the largest number of coils or
sections C, C, also wound and connected as above described having thus also double
the number of sections in its commutator L, than coils on the armature. The
diagram in Figure 3 shows this clearly. The armature A, is carried by the
flange G, in the following manner; all around the armature and between each two
adjacent sections or armature coils, are placed iron bars F, F, properly insulated
from the coils C, C, and lengthwise projecting beyond the same as shown in
Figure 2, the flanges G, are grooved around their circumference and receive a ring
of some insulating material, a groove is cut in the insulating rings H, and in these
grooves the ends of the bars F, are fitted, so that when the two flanges are placed
upon the shaft ✗, the armature is held in place, perfectly concentrical with the
shaft X, with which it is to revolve.

page_text: Figure 2, shows further how the two commutators are disposed upon the shaft X,
and how the armature sections are connected to their respective commutator
sections, the conducting wires c, c, are passed through the inside of both
commutators I, and J; the wires c, c, are brought from the armature coils C, C, to
the commutater. J, while those c', c' are brought from armature sections C, C, to
commutator i. The field magnets, or the magnetic frame, is constructed and built
up in the following manner; the iron plates M, M, M, etc., are first all drilled as
shown in Figures 1, and 2, and a certain number, say 8, are placed on the two
bolts, 0, 0; between each two plates a washer is placed so as to distance all the
plates from one another; the distance can vary say from one sixteenth to about one
eight inch, this disposition prevents the so called "Foucalt" currents and under
prolonged action the field magnets remain cool. The plates when riveted together
are ready to be placed in the said mould and have the back plate N, cast on; in
order to prevent the cast iron from running in between the plates N, M, etc. theso
spaces are filled up with moulders sand which is afterwards removed when the
casting is cleaned. In this way the plates M, M, etc. are intimately united to the
back plates forming perfect magnetic contact with the same.
The free ends of the plates M, M, are afterward planed to receive the pole
pieces K, K, between which the armature is to revolve. The pole pieces K, K, are
rigidly fixed to the plates M, M, by strong screws or other suitable means. The
magnetic cores M1, M2, are now held in place between the cast iron bottom and top
plates O and O*, by means of strong screws passing through the ends of Oi,
and O, into the back plates N and N ; the pole pieces are further held up and in
position by adjusting screws a and a. The posts carrying the armature shaft are
placed upon the projections P, P, as shown in Figures 1, 2, and 3. The winding of
the field magnets can be done in the usual manner with a single conductor, or the
helix can be formed of a cable such as described in Letters Patent granted to
Charles Joseph Van Depoele in the United States October 2nd 1883, N° 285,857.
In the first case the regulation of the machine is performed by moving the
brushes upon the commutator, while in the second case the terminals of the
insulated cable conductors are brought out to an automatic contact breaker as
shown in Figure 8, which is similar to the arrangement described in the Patent
above referred to. The main current can be passed through the solenoid or hollow
electromagnet m, as shown in the present Drawing, or a derived current can be
passed through said solenoid taken between the main conductors of the dynamo ;
when the current in the main line becomes too powerful the core of the solenoid is
drawn up higher and breaks contact between the bars C and C; thus allowing less
current to flow around the field magnets, reducing the energy of the same and
hence diminish the production of current in the dynamo. It will be seen that the
general features of this dynamo are similar to the one for which Charles Joseph
Van Depoele obtained Letters Patent in the United States dated September 21,
1880; however several important improvements have been brought to this dynamo
from time to time, with a view to make its efficiency higher, its working and
regulation easier and more perfect.
;
By the special construction of the armature core I do away as much as practical
with all local magnetic action of said core upon the armature coils. It is well
known that in the case of a drum armature as ordinarily constructed, the core does
not change polarity as rapidly as is desirable, which has for effect, first to heat
the core, and second to diminish the production of current in the armature coils
the armature core as here above described is constructed with a view to act
more instantaneously on its coils than in a regular drum armature as ordinarily
constructed; the iron wire rings B, B, etc., being magnetically insulated from the
bars D, D, etc. in passing from one field magnet pole to the other, are de-magnetized
and re-magnetized faster than the iron rings; said bars being light and not in
magnetic contact with one another nor with the core; consequently a much
prompter action is obtained upon the armature coils of this construction, than in

page_text: the case of a core without the bars, on account of the slowness of action in said
core to change its polarity under the influence of the field magnets, and the coils of
the armature,
On considering the field magnets it will be found that the magnetism is con-
centrated towards the center of the machine forming the field of force in which the
armature is to revolve. The construction of the cores practically does away with
all heating under a maximum of magnetization, so that the machine can operate
any length of time, without danger of overheating or injuring the insulation. As
shown in Figures 1, 2, and 8, the field helices are made up of a cable consisting of
a number of individually insulated fine wires, the inner ends of the cable coils are
attached to the brushes J, and J. Said brushes bearing upon commutator J,
while the outer terminals of the cable helices are brought out to the insulated
contacts i, i, i, etc., when the bars b¹, and 62, are down upon all the contacts i, i, i,
etc. the full amount of current produced in the coils C, C, etc. is passing through the
field helices or coils, and the machine capable of exerting its maximum duty,
however, as soon as the current in the machine is too powerful the solenoid m will
draw up its core and lift the bars b, and b, from the contacts i, i, i, etc. the current
will be diminished according to the number of, wires cut out of circuit. By thus
varying the internal resistance of the field circuit regulation is obtained without
the need of outside resistances or other devices.
'
In the present Drawings the brush holders are carried by a brass ring r, which
can be moved around the commutators, when needed, and also provided with lock
nuts running in proper slots so as to keep the brushes in place. This brass ring is
mounted upon a wooden face plate w, which is held in position by means of screws
engaging in the pole pieces K, K. As shown in Figures 8 and 9, the brushes are
so arranged as to move together, although in some cases I mount each set separate,
⚫ so as to work independently if so desired.
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
First. In a dynamo electric machine, an armature core of the drum type, composed
of a number of iron bars riveted to two or more solid iron rings, the whole when,
put together forming a cylinder or drum; a number of iron rings composed of
galvanized iron wire placed upon said cylinder and distanced from one another,
and an equal number of iron bars corresponding with the inner ones, placed outside
the iron and wire rings, the inner and outer bars being placed opposite one another,
and parallel with the axis of rotation of the said drum, substantially as described.
Second. In a dynamo electric machine, an armature core composed of a number
of galvanized iron wire rings, placed upon a cylinder built up of iron bars and
solid iron rings, in combination with iron bars placed on the outside of the iron
rings and opposite the bars on the inside of the rings, the whole being covered
with proper insulating material, as described and set forth.
Third. In a dynamo electric machine, the armature core composed of two or
more iron rings having riveted on their inside a number of iron bars so distanced
from each other as not to touch each other longitudinally, in combination with a
number of galvanized iron wire rings, placed upon the cylinder also distanced
from one another, and iron bars; properly secured to the outside of the rings and
opposite the bars on the inside of the cylinder, as described and set forth.
Fourth. In a dynamo electric machine, an armature core of the drum type,
consisting of iron bars and rings substantially as described, in combination with
the armature coils wound in sections, over the armature core, the wire coils being
so wound that each section shall correspond to a pair of iron bars, and directly
placed or wound over the same, and parallel therewith, substantially as described.
Fifth. An armature of the drum type composed of iron bars and rings substan-
tially as described, in combination with armature coils wound in sections over said
bars, each single section having one or more extra loops or terminals brought to the

page_text: outside, which are to be connected to commutator sections, the circuit however
from the inner to the outer terminal of each section being continuous, as described
and set forth.
Sixth. An armature for dynamo electric machines, having copper conductor
wound in sections, and each section to be continuous from its inner to its outer
terminal, and also provided with an intermediate additional terminal, placed in the
circuit of said sections or coils, and proper connections between said terminals and
the commutator of the armature, in order to collect from saïd sections only part of
its current at a time, and successively as described and set forth.
Seventh. An armature for dynamo electric machines, having its copper conductor
wound over a core built up of iron rings and bars as described, said copper con-
ductor being divided in sections corresponding in number to the iron bars in said
core, the inner terminal of each section being connected to the outer terminal of
the next in order, until the whole forms one closed circuit, and an additional
terminal placed and connected so as to divide the copper conductor in each
individual section or coil, all said terminals being connected to separate sections
of a commutator from which the current produced in the armature coils is to be
collected.
Eighth. In a dynamo electric machine, an iron field magnet core around which
the copper conductors is wound, built up of a number of soft iron plates M, M, all
riveted together but leaving an air space between each plate and the next, in
combination with a back plate N, of cast iron, cast solid to one end of said plates,
substantially as described, and a pole piece secured to the free end of said soft iron
plates in front of which the armature is to revolve, as set forth.
Ninth. In a dynamo electric machine, an iron core and frame forming the field
magnet, consisting of the plates M, M, etc. riveted together and an iron back plate N,
cast thereto, in combination with the pole pieces K, the top and bottom plates 0¹,
and O2, to which the plates N, and N, are bolted, forming together a solid frame,
the lower plate O¹, being provided with proper extensions from its sides, upon
which the bearings or boxes for the armature shaft are secured, substantially as
described.
Tentb. In a dynamo electric machine, the field magnets for the same, consisting
of soft iron cores built up as described, around which the copper conductors or field
coils are wound, in combination with the cast iron bottom and top plates, the
bottom plate so constructed as to support the field cores by the plates N, N, and
the adjustable screws, said bottom plate also being provided with extensions P, in
its neutral part upon which the posts are fixed, carrying the armature; and in
combination with the cast iron cover or top plate, serving to strengthen the general
frame and protect the armature and field coils.
Eleventh. In a dynamo electric machine, an armature, wound with two inde-
pendent circuits, one circuit to do the outside work, the other to keep up the
magnetic field of the machine, when operating in combination with the cable helices
or field coils of the machine as described, and proper means for allowing the current
to circulate through a greater or smaller number of the insulated wires constituting
said cable in order to modify the efficiency of the machine as described and set
forth.
Twelfth. In a dynamo electric machine, an armature wound with two sets of
coils, one set to furnish current for the work outside of the machine, the second set
to be made available to energize the field magnets of the machine by transmitting
its current through the field helices consisting of a number of fine insulated wires
made up in a cable, and proper means for cutting out or in circuit a larger or
smaller number of individual conductors in said cable for the purpose of modifying
the production of current in the coils doing the outside work, substantially as
described.
Thirteenth. In a dynamo electric machine, the field magnet coils, consisting of a
cable made up of a number of well insulated fine wires in combination with a set

page_text: of independent coils on the armature of the machine, not in common with the
armature coils furnishing the working current; the current of the independent set
of coils to circulate through all the insulated conductors of the cables, connected in
multiple arc, whenever the machine is doing its maximum duty, or through a
smaller number when the machine is working at less than full capacity, substantially
as set forth.

page_text: FIG. 4.
C.
FIC. 5.
FIG. 6.