IMPROVE- MENTS IN ELECTRICAL GENERATORS AND ENGINES AND IN APPARATUS OR MEANS FOR REGULATING GENERATORS OF ELECTRICITY
Year: 1882

page_text: LETTERS PATENT to Thomas John Handford of 42 Southampton Buildings
in the County of Middlesex Patent Agent for an invention of "IMPROVE-
MENTS IN ELECTRICAL GENERATORS AND ENGINES AND IN APPARATUS OR
MEANS FOR REGULATING GENERATORS OF ELECTRICITY" A communication
from abroad by Thomas Alva Edison of Menlo Park in the State of New
Jersey United States of America.
PROVISIONAL SPECIFICATION left by the said Thomas John Handford at
the Office of the Commissioners of Patents on the 1st May 1882.
THOMAS JOHN HANDFORD of 42 Southampton Buildings in the County of
Middlesex, Patent Agent "IMPROVEMENTS IN ELECTRICAL GENERATORS AND
ENGINES, AND IN APPARATUS OR MEANS FOR REGULATING GENERATORS OF
ELECTRICITY A communication from abroad by Thomas Alva Edison of Menlo
Park in the State of New Jersey United States of America
"
This Invention relates to dynamo or magneto electric machines, or electric
engines, and to apparatus or means for regulating the generative capacity of
dynamo or magneto electric machines.
The object of the first part of the invention is to produce a dynamo or magneto
electric machine or electric engine, which will possess the features of exceedingly
low resistance, and great strength, compactness, and economy.
This is accomplished by the use of a number of discs (preferably of copper) for
the bobbin or winding of the armature, which discs are connected to develope
(when the machine is used as a generator) a continuous current of electricity
having a tension due to the electro motive force of a number of discs.
According to one modification, these copper discs are arranged in two sets, placed
on oppposite sides of an iron plate, which is of circular shape, and forms the core
of the armature. The discs are securely clamped together and to this central plate
or core, such discs being separated from each other and from the central plate or
core by insulating material. The exciting magnet has its polar extensions placed
on opposite sides of the peculiar armature. These polar extensions are hollowed

page_text: out or chambered and inclose opposite sides of the armature, the approaching faces
of the polar extensions being reduced by bevelling the outer sides of such polar
extensions, so that the direct attractive force between such polar extensions will
be small compared with that between the polar extensions, and the core of the
armature.
The copper discs therefore cut lines of force extending from each polar extension
to the iron core.
Those on one side of the central plate or core all have currents
set up in the same direction, but in the opposite direction to those on the other
side. Cross connections are provided at the periphery of the discs, which connect
the discs in series, so that a continuous current is generated having a tension due
to a number of discs. Connections are made with the commutator cylinder upon
which the commutator brushes or springs bear and these commutator connections
may run either to the cross connections between the discs at their peripheries, or
to the discs themselves, at their centres around the armature shaft.
According to another modification the copper discs are placed all on one side of
the iron plate, the arrangement of the exciting magnet (or magnets) being the
same as in the first described modification of machine. The discs having current
induced in them all in the same direction, direct cross connections between the
dises at their peripheries cannot be used. The discs are connected in series so as
to produce a continuous current having a tension due to a number of discs, by
means of concentric copper rings, which are placed preferably around the outside
of the armature, and are properly insulated from each other as are also the copper
discs. The bars of the commutator cylinder are connected with the discs at their
centres, next to the armature shaft, or with the outside rings.
The field
The object of another part of the invention is to produce simple and efficient
means for regulating the generative capacity of dynamo or magneto electric
machines. This is accomplished by providing means whereby the current passing
through more or less of the coils of the exciting or field of force magnet may be
reversed. For this purpose the exciting magnet is wound in sections or bobbins,
the ends of each bobbin being connected with a current reverser.
circuit in which these current reversers are placed, may be a multiple arc circuit
from the main conductors supplied by the machine, or it may be supplied from
an external source of energy. It will be seen that the reversal of the current in a
part of the bobbins of the field coils, will weaken the field magnet, and that such
field magnet can be regulated in strength as desired by reversing the current in
more or less of such bobbins.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Thomas John Handford in the Great Seal Patent Office on the
31st October 1882.
THOMAS JOHN HANDFORD of 42 Southampton Buildings in the County of
Middlesex Patent Agent "IMPROVEMENTS IN ELECTRICAL GENERATORS AND
ENGINES AND IN APPARATUS OR MEANS FOR REGULATING GENERATORS OF
ELECTRICITY" A communication from abroad by Thomas Alva Edison of Menlo
Park in the State of New Jersey United States of America
The said Invention relates to dynamo or magneto electric machines or electric
engines and to apparatus or means for regulating the generative capacity of
dynamo or magneto electric machines.
The object of the first part of the said invention is to produce a dynamo or
magneto electric machine or electric engine which will possess the features of
exceedingly low resistance and great strength compactness and economy.
This is accomplished by the use of a number of discs (preferably of copper) for
the bobbin or winding of the armature, which discs are connected to develope
(when the machine is used as a generator) a continuous current of electricity
having a tension due to the electromotive force of a number of discs.
One form of the machine is shewn in figures 1 to 6 inclusive of the accompanying
drawings. Figure 1 is a side elevation of the machine. Figure 2 a vertical cross
section of the same taken along the line of the armature shaft. Figure 3 an
elevation of the commutator side of the armature the commutator cylinder being
in section. Figures 4 and 5 elevations of copper inductive discs and Figure 6 an
elevation of an insulating disc.
With reference to these figures N S are the polar extensions of the field magnet A.
which is mounted on a suitable base B. These polar extensions are hollowed out
on their inner faces forming chambers which inclose opposite portions of the
armature and in which the said armature revolves. The sides of the polar
extensions N S are bevelled as shewn at a so as to reduce the attractive force
acting directly across between the polar extensions. The armature is composed of
an iron core C (which is a circular plate keyed to the shaft D) and two sets E F
of copper discs. These discs are placed on opposite sides of the central plate or
core and are insulated from each other and from the core by discs G of insulating
material preferably paper. The discs are clamped together and to the core by
brass screw rings b turning on the ends of the extended hub c of the core; but
the discs may be additionally secured by insulated bolts passing directly through
them. The discs have projections de on their periphery. The projections of the
two sets of discs are joined by cross connections so that the discs will be connected
in a continuous and symmetrical series. For example assuming that 11 discs are
employed in each set and that the discs of the set E are numbered in the direction
approaching the core C, 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21 and that the discs of the
set F are numbered in the direction approaching the core C, 2, 4, 6, 8, 10 12, 14,
16, 18, 20, 22 the outer disc 1 of the set E may be connected to the outer disc 2 of
the set F disc 2 to disc 3, 3 to 4, 4 to 5 and so on throughout the two sets of
discs 21 and 22 being finally connected to gether. H is the commutatior cylinder
to which the discs are connected by rods or plates f the alternate connections of
the discs with each other being shewn as thus connected with the bars of the
commutator cylinder. The commutator connections may be made with the discs
at their inner edges next to the shaft such discs having larger openings at their
centre and being provided with lugs or projections for the purpose. This latter

page_text: form of commutator connection is shewn as employed in another construction of
the machine hereinafter described The yoke carrying the commutator brushes or
springs is shewn but such brushes or springs are omitted for clearness in
illustration. The lines of force at each pole of the exciting magnet move between
the pole and the core of the armature on each side of the said core. The discs of
each set cut in opposite directions on their opposite portions the lines of force
from the opposite poles of the magnet; hence the currents generated in the discs
of each set flow all in the same direction. The discs of one set cut in each field
lines of force moving in the opposite direction from those cut by discs of the other
set in the same field; hence the currents generated in one set of discs flow in
the opposite direction to those generated in the other set. The result at the
commutator is a continuous current having a tension due to the electromotive
force of a number of discs.
As an Engine it will be understood the operation is reversed.
This armature has an exceedingly low resistance and is compact and strong.
Another form of the machine is shewn in Figures 7 and 8 of the accompanying
drawings Figure 7 being a vertical section through the armature and the polar
extensions of the exciting magnet and Figure 8 a separate elevation of the
armature from the commutator end the commutator cylinder being in vertical
section.
With reference to these figures N S are the polar extensions of the exciting or
field of force magnet which polar extensions are chambered or hollowed out and
have bevelled sides a and are otherwise constructed and arranged as hereinbefore
described with reference to figures 1 to 6 inclusive. The armature has an iron
plate B mounted upon a shaft C. Secured to one side of the iron plate by insulated
bolts or otherwise are a number of copper discs D which are insulated from each
other and from the iron plate preferably by means of paper discs. A number of
insulated copper rings or segments of rings E are supported by the rim of the
plate B and connect the copper discs in a continuous series in a manner substantially
similar to that in which the discs of the two sets E F are connected in the arrange-
inent herein before described with reference to Figures 1 to 6. The discs are
connected with the bars of the commutator cylinder F by strips or rods b extending
from the open centres of the discs to the bars of such commutator cylinder but the
commutator connections may be made with the rings or segments of rings E by
means of rods or plates connected with such rings and extending down to the bars
of the commutator cylinder.
The discs being on one side only of the core all have currents generated in them
in the same direction which currents are formed by the ring connections into one
continuous current having a tension due to the electromotive force of a number
of discs.
When used as an engine the operation is the reverse of that described.
The object of another part of the said invention is to produce simple and efficient
means for regulating the generative capacity of dynamo or magneto electric
machines. This is accomplished by providing an arrangement whereby the current
passing through more or less of the coils of the exciting or field of force magnet
may be reversed.
Means for this purpose are shewn in figure 9 of the drawings which is a
diagrammatic view of a dynamo or magneto electric machine embodying this part
of the said invention.
With reference to that figure 1, 2, are the main conductors leading from the
machine in derived or multiple arc circuits from which are the lamps or other
translating devices a. From the conductors 1, 2 is also taken the multiple arc
circuit 3, 4 including the helices A of the field magnet; but such field circuit may
be supplied from an external source of electrical energy.
One helix is shewn as wound in separate sections or bobbins b the ends of the
wire of each section being connected with a current_reverser.
The arrangement of
the lowest section will illustrate that of the rest. The wire ends c c are divided

page_text: into branches e e¹ and ƒ ƒ¹ running to separate contact plates. B is a current
reversing lever moving the pivotted arms h h¹ which are connected by an insulating
cross piece h². When levers h and h¹ are in contact with e, and f' as shewn in
the drawing the current flows through the section or bobbin in one direction and
it flows in the opposite direction when such levers are in contact with fand e¹.
The machine is most powerful when the reversers are shifted to give the current
direct passage through all the coils of the field magnet and its generative capacity
can be reduced to any desired extent by reversing the current in the proper
number of sections or hobbins. Although only one of the helices is shewn as
wound in sections it is obvious that both helices may be so arranged and when the
wire is wound upon the core in layers one above another any number of the layers
(one or more) may be arranged in connection with one or more current reversers.
It is evident that the form of the current reverser is not material since any well
known or suitable construction may be used.
nature of the said
used or carried into
be novel and original
Having now described and particularly ascertained the
Invention and the manner in which the same is or may be
effect I would observe in conclusion that what I consider to
and therefore claim as the Invention secured to me by the hereinbefore in part
recited Letters Patent is:-
First-Constructing dynamo or magneto electric machines or electric engines
with the inductive portion or bobbin of the armature composed wholly or
principally of metal discs connected in such a manner that the machine when used
as a generator will develope a continuous current having a tension due to the
electro-motive force of a number of discs substantially as hereinbefore described.
Second-The combination with the enclosing and bevelled polar extensions of
the exciting magnet, of the armature having a plate or core, a number of inductive
discs on one or on each side of the said plate or core, and connections between such
discs and with the bars or strips of a commutator cylinder, substantially as
herein before described.
Third-The combination with the field magnet of a dynamo or magneto
electric machine having its coils divided into a number of separate sections, of
current reversers for reversing the polarity of current in more or less of such
sections substantially as and for the purpose herein before described.
In Witness whereof I the said Thomas John Handford have to this my
Specification set my hand and seal this thirty first day of October, in the
year of Our Lord One thousand eight hundred and eighty two.