ROVEMENTS IN APPARATUS FOR THE GENERATION AND UTILIZATION OF ELECTRICITY
Year: 1880

page_text: LETTERS PATENT to William Robert Lake, of the Firm of Haseltine, Lake,
& Co., Patent Agents, Southampton Buildings, London, for an Invention
IMPROVEMENTS IN APPARATUS FOR THE GENERATION AND UTILIZATION
OF ELECTRICITY." A communication from abroad by Elihu Thomson, of
of
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Disin
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PROVISIONAL SPECIFICATION left by the said William Robert Lake at the
Office of the Commissioners of Patents on the 28th September 1880.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. "IMPROVEMENTS IN APPARATUS FOR
GENERATION AND UTILIZATION OF ELECTRICITY." [A communication from abroad
by Elihu Thomson, of New Britain, Connecticut, United States of America.]
THE
The present Invention relates to improvements in the generation and utilization
of electricity by means of magneto- and dynamo-electric machines of improved
construction, whereby a very high electro-motive force is obtained with the
advantages of lightness, compactness, and durability.
One of the objects of the present Invention is to make the field magnet coils, or
coils through which the magnetizing current is sent, serve also the purpose of
directly magnetizing the iron contained in the armature. This is accomplished by
winding the magnetizing coils upon the field magnets so as to enclose them, and
also to enclose the armature which revolves between the poles of the magnets, as
hereinafter described.
Another object of the present Invention is to provide a form of field magnet
frame which shall fully utilize both the internal and external magnetizing effects
of the before mentioned coils. To this end the field magnet frame instead of
simply being partly enclosed by the magnetizing coils serves in turn to enclose said
coils in the manner hereinafter described.
Another object of the present Invention is to provide an armature for dynamo-
electric machines, all parts of the insulated wire of which shall at all times be
under the direct influence of the field magnets, and thus avoid the use of inactive
wire, thereby increasing the electro motive force of the currents generated, and
reducing to a minimum the length of armature wire necessary to generate a given
electro-motive force.
Another object of the present Invention is to provide an armature for dynamo

page_text: electric machines, the magnetizing effect upon which shall not be limited to the
point of magnetic saturation of the field magnets, but shall be further reinforced
by the direct action upon the iron core of said armature, and the insulated wire
surrounding the same, of the currents traversing the whole of the field magnet
coils, which coils are made to enclose and surround the revolving armature, so that
the iron core of the armature becomes practically but a moveable extension of the
field magnets themselves.
In carrying the said Invention into practice I provide a hollow shell or cylinder
of iron, which may sometimes be made solid, constituting one pole of the field
magnet. Its outer edge is flanged, and its inner face shaped to conform to the
rounding outline of the armature of the machine. An opening or openings through
the inner face is provided to allow circulation of air through the centre of the
shell. A similar shell of iron is placed opposite to the said shell, it being also
flanged, and it constitutes the opposite pole of the field magnet. Bars or masses
of iron join the flanges, preferably let in holes in the latter, and are of sufficient
number and size to make thorough magnetic contact between the said flanges.
Coils of insulated wire surround the field magnet poles and also the armature of
the machine, and serve for the direct magnetization of said poles and of the
armature itself. Rings of metal or other suitable material may be provided to
keep the coils in place, since in most cases the latter project beyond the poles and
over the armature. The electric current traversing the coils and for inagnetization
is in the same direction in both coils, and may be derived either from the machine
itself or from any other suitable source. The opposing faces of the poles are
thereby magnetized of opposite polarity respectively. The bars are situated near
the outside of the coils, and are therefore magnetized by said coils, the direction of
their magnetization being that proper to intensify the magnetization of the poles.
The opposing faces of the magnets, between which faces the armature revolves, are
portions of a hollow sphere, the armature itself when wound with wire being
spherical in outline, the construction and operation of which is to be hereinafter
described.
The armature employed in the present Invention is spherical in form, it being
found to possess great advantages. It must be understood however that I do not
confine my Invention to an armature of spherical shape, but may shape the field
magnet poles so as to make use of other curved forms of armature, as a prolate or
oblate spheroid, an ellipsoid, or figures the outlines of which are partly curved and
partly straight, the main requisites being that the armature shall permit of almost
complete enclosure by the field magnet coils, and that the wire and iron of said
armature shall not present too great inequalities of surface to the poles of the
magnets. The iron core of the armature may be made in a variety of ways, the
necessary condition being that it shall contain sufficient iron for thorough
magnetization, and that the iron be sufficiently subdivided to prevent the circu-
lation of local currents in it.
An iron armature core employed to obtain a spherical outline in the armature
when worked with its insulated wire is constructed as follows, that is to say:
Two plates fastened to a shaft and perforated or otherwise provided with slits or
openings are set at such a distance apart as to leave space between them for the
winding of soft iron wire or strips to a spherical form. The iron wire is pre-
ferably varnished or coated with a non conductor before being placed in position.
The iron core thus obtained presents the form of a sphere, flattened at those
portions where the axis enters, and is afterwards wound over with insulated copper
wire. Instead of the wire, rings or bars of iron, which when fitted together give
the required outline, may be used, the various pieces being preferably insulated
from one another. Considerable latitude in the construction of the iron armature
core used in this Invention may be exercised, since said core is not alone dependent
for its magnetization upon the induced magnetism it receives from the field magnet
poles, but is directly magnetized by the field magnet coils which surround the
armature.

page_text: Upon the armature core it is not difficult to wind insulated wire so as to obtain
a nearly spherical outline; small projections made upon the edges of the plates
tend to keep the convolutions in place. The number and connections of the coils
on the armature will vary according to the form and arrangement of the com-
mutator or the purpose to which the current developed is to be applied, and it is
not intended therefore to limit the present Invention to any particular arrangement
of the coils on the armature. I find however a special winding of wire and
commutator to be well adapted to the purposes of iny Invention. This special
winding and commutator will be herein described, that is to say :-
Three coils of insulated wire are wound upon the armature, intersecting one
another at the axis at angles of approximately 60°. The manner of winding these
three coils so as to secure equality in lengths of wire in them and uniformity of
outline of the armature is substantially as follows:-First, one-half of the wire of
one of the coils is wound on, then one-half of the second coil is wound, then the
whole of the third coil is wound on; next, the remaining half of the second coil,
and finally the remaining half of the first coil. It will thus be seen that portions
of the first coil will respectively underlie and overlie the other two coils where
they intersect, and portions of the second coil will likewise underlie and overlie
the third coil.
If the armature be run for reversed currents no commutation is necessary, but
the ends of the armature coils are carried out in the manner usual in such a case.
The distribution of magnetic polarity in a machine constructed, as herein
described, is as follows:-The armature core receives an inductive action from all
directions; no portion of the wire surrounding the core can escape the powerful
direct action of the field of force from the poles. In all machines hitherto produced
a considerable portion of the arinature wire has escaped this direct action. In the
Paccinotti," "Gramme," and similar. machines, the wire in the interior surface of
the ring thus escapes; in the "Siemens" and similar machines it is the wire that
passes over the ends of the cylindrical core, and from the overlapping of the
numerous coils at the ends of the cylinder this inactive wire bears a considerable
proportion to the rest or active portion.
cr
In a cylindrical armature, as commonly used, where portions of the armature
wire do not at any time come under the action of the field magnet poles. To
reduce the loss due to inactive wire to a minimum a cylindrical armature is
employed, whose length is relatively much greater than its diameter, thus giving
rise to inconvenience of form and diffusion of magnetic field. Moreover, there is
no convergence in all directions of the magnetic force upon the armature. According
to my Invention the distribution of the magnetic polarization is induced by the
coils in the poles and in the bars, both inner and outer sides of the magnetizing
coils being utilized. This feature enables great concentration of magnetic force to
be obtained.
Besides the convergence of the field of force upon the armature in all directions,
there is yet to be considered the direct magnetizing inductive action of the coils
upon the whole of the armature wire. A powerful current is sustained in the coils
from a suitable source of electricity. The armature revolving, currents of con-
siderable strength are induced in the coils of said armature, which result mainly
from the effect of the coils which give polarity to the armnature core, and also
act by direct induction upon the moving arinature coils. It would be sufficient to
revolve only the coils of the armature, allowing the core to remain stationary, but
the practical difficulties of construction are thereby increased.
I inay provide a shaft passing transversely through a coil, which shaft bears
several wire hoops whose planes pass through the axis at angles with one another,
and correspond to or represent convolutions of armature wire. If this arrangement
be revolved, currents are set up in the wire hoops due to direct inductive action of
the currents in the coil.
The following is the manner of connecting the terminals of the armature coils:-
There are six ends of wire from three coils; three of these ends taken alternately

page_text: are connected together at a point, and the remaining three alternate ends are con-
nected singly to three insulated segments of a commutator, one of the ends of one
coil will be connected to the other coils at the point first mentioned, and the other
to a segment of the commutator. Similarly the other two coils have each a terminal
going to the said point, and one each also to the two other segments in the com-
mutator; care must be exercised to connect to the segments of the commutator only
such terminals as are alternate, or which lead from positions on the circumference
of the armature 120° apart. The three segments are made from a copper ring or
otherwise, and constitute a circular conducting ring with slits or gaps at equal
distances apart, and completely separating the segments. Strips of copper or other
metal rub upon the surface of the segments, and are supported in any suitable way
so as to touch at opposite sides of the ring of segments. Their position with respect
to the segments alterable during operation, so as to secure the best position for
taking off the currents generated in the armature wire. Since the segments on one
side of the commutator will always be of opposite polarity to those on the opposite
side, a position is soon found where the strips or collectors will take off a con-
tinuous uninterrupted current of a strength depending on the size and speed of the
machine. This simple arrangement of part gives with low speed a current practically
continuous and of great power. Wires are led from the strips to the point where
the electric force is utilized. This circuit, in most cases, includes the wire of the
coils, in order to magnetize the machine by the currents generated. The detailed
construction of the commutator is as follows:-The shaft has upon it two flanges,
between which is mounted the segmental ring of the commutator. Each segment
has two rods passed through it or otherwise fastened to it projecting through holes
in the flanges, but insulated from said flanges by rings or bushings of vulcanite or
wood. The segments are mounted at some distance from the flanges on each side,
and their inner diameter is so much larger than the shaft passing through the centre
as to leave an air space between the segments and the shaft. This serves, in cou-
junction with the lateral spaces between the segments and the flanges, as a most
effectual air insulation of the segments from one another and from the shaft. The
insulated wires from the armature coils pass through the shaft, and are connected
to the ends of the rods, one from each segment of the commutator. The slot or gap
between any two segments of the commutator is made preferably at a somewhat
oblique angle to the ring. The angle may be varied within moderate limits, but
when radii at the two ends of the slot would differ 20° in angular position with
respect to cach other, the obliquity may be considered sufficient; a rod is employed
serving as a support to the segment.
In the practice of my Invention single, double, or other wires may be wound
upon the magnet coils or armature, and the inultiple terminals so provided may be
connected in various ways in series or in multiple arc or for separate circuits, and
multiple commutators may in like manner be used. These and similar modifi-
cations of circuits will suggest themselves to those versed in the subject.
Besides the many advantages of my Invention from an electrical and economical
standpoint there are several mechanical advantages.
The complete enclosure of the armature by the magnet frame prevents injury
to it by objects being brought into contact with it while revolving.
The magnet poles also being enclosed cannot attract pieces of iron inadvertently
left near the machine and cause injury.
The external iron of the machine serves also as an effective protection to the
magnet coils, preventing injury during shipment, or otherwise.
Although I have described my Invention as a generator of electric currents, it is
to be understood that I may employ it in the conversion of electricity into motive
power, and to this latter use it is admirably adapted, by reason of the form and
disposition of its various parts, and also of the electrical principles involved.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Robert Lake in the Great Seal Patent Office on the 26th
March 1881.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. " IMPROVEMENTS IN APPARATUS FOR THE
GENERATION AND UTILIZATION OF ELECTRICITY." A communication from abroad
by Elihu Thomson, of New Britain, Connecticut, United States of America.
This Invention relates to improvements in apparatus for the generation and
utilization of electricity by means of magneto- and dynamo-electric machines of
improved construction, whereby a very high electro-motive force is obtained with
the advantages of lightness, compactness, and durability.
One of the objects of the said Invention is to make the field magnet coils or
coils through which the magnetizing current is sent serve also the purpose of
directly magnetizing the iron contained in the armature. This is accomplished
by winding the magnetizing coils upon the field magnets so as to enclose them and
also to enclose the armature which revolves between the poles of the magnets as
hereinafter described.
Another object of the present Invention is to provide a form of field magnet
frame which shall fully utilize both the internal and external magnetizing effects
of the above mentioned coils. To this end the field magnet frame instead of simply
being partly enclosed by the magnetizing coils serves in turn to enclose the said
coils in the manner hereinafter described.
Another object of this Invention is to provide an armature for dynamo-electric
machines, all parts of the insulated wire of which shall at all times be under the
direct influence of the field magnets, and thus avoid the use of inactive wire,
thereby increasing the electro motive force of the currents generated, and reducing
to a minimum the length of armature wire necessary to generate a given electro
motive force.
Another object of the present Invention is to provide an armature for dynamo
electric machines, the magnetizing effect upon which shall not be limited to the
point of magnetic saturation of the field magnets, but shall be further reinforced
by the direct action upon the iron core of the said armature, and the insulated
wire surrounding the same, of the currents traversing the whole of the field magnet
coils, which coils are made to enclose or surround the revolving armature so that
the iron core of the armature becomes practically but a movable extension of the
field magnets themselves.
Figure 1 is a side elevation partly in section of a machine or apparatus
constructed according to this Invention, and
Figure 2 is an end elevation of the same.
Figure 3 is a plan or top view partly in section.
Figures 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, and 16 are detail views illustrating
the construction and operation of various parts of the said apparatus.
Like letters indicate the same parts throughout the Drawings.
In Figure 1 N represents a hollow shell or cylinder of iron constituting one pole of
the field magnet.
The outer edge F of this cylinder is flanged, and its inner
face H is shaped to conform to the circular outline of the armature of the machine
as shewn.
If desired. I may use a solid cylinder instead of a hollow one. An
opening (or openings) through the face His provided, as at O, to allow the circulation
of air through the centre of the shell N. A similar shell of iron S is placed

page_text: opposite to the said shell N, and is also flanged, as shewn at F'; this shell S
constitutes the opposites pole of the field magnet. In the Drawings the said
shell S is shewn covered by its coil C¹, C¹. Bars or pieces of iron B, B, serve
to connect the flanges F, F, and are preferably let into holes in the latter;
these bars are of sufficient number and size to make thorough magnetic contact
between the aforesaid flanges F, F¹. The coils of insulated wire C, C, and C¹, C',
surround the field magnet poles N and S and also the armature of the machine,
and serve for the direct magnetization of the said poles and of the armaturo itself.
Rings R, R, of metal or other suitable material may be provided to keep the
coils C, C, and C, C', in place, since in most cases the latter project beyond the
poles N and S and over the armature, If desired the two coils C, C, C¹, C¹, may
be combined to form a single coil. The electric current traversing the coils C
and C¹ for magnetization travels in the same direction in both coils, and may be
derived either from the machine itself or from any other suitable source. The
opposing faces of the poles N and S are thereby magnetized with opposite polarities.
The bars B are situated near the outside of the coils C, C', and are therefore
magnetized by the said coils, the direction of their magnetization being such as to
intensify the magnetization of the poles N and S. The opposing faces H, H, of
the said magnets N and S, between which faces the armature revolves, form, as
shewn, portions of a hollow sphere, the armature itself when wound with wire
being spherical in outline. The construction and operation of the said armature
are hereinafter described.
In Figure 1 J represents a portion of the arm supporting the journals of the
shaft of the armature, and f, f, are the feet of the machine. The commutator is
shewn in Figure 2 at K, and the driving pulley at P.
The armature employed in the present Invention is spherical in form, as above
stated, this form being found to possess great advantages. I wish it understood
however that I do not confine my Invention to an armature of spherical shape,
but may shape the field magnet poles so as to make use of other curved forms of
armature, as a prolate or oblate spheroid, an ellipsoid, or figures the outlines of
which are partly curved and partly straight, the main feature being that the
arinature shall permit of almost complete enclosure by the field magnet coils, and
that the wire and iron of the said arinature shall not present too great inequalities
of surface to the poles of the magnets.
The iron core of the armature may be made in a variety of ways, the necessary
conditions being that it shall contain sufficient iron for thorough magnetization,
and that the iron shall be sufficiently subdivided to prevent the circulation of local
currents therein.
Figure 4 shews in side view an iron armature core employed to obtain a spherical
outline in the armature when wound with its insulated wire; and Figure 5 is an
end view of the same. The said armature has two plates D, D, fastened to the
shaft X, and perforated or provided with slits or openings a, a, Figure 4. These
plates are set at such a distance apart as to leave space between them for the
winding of soft iron wire or strips to a spherical forin, as shewn at W, Figures 4
and 5. This iron wire is preferably varnished or coated with a non conductor
before being placed in position. The iron core thus obtained presents the form of
a sphere, flattened at those portions where the axis X enters, and is afterwards
surrounded with insulated copper wire to the outline shewn by dotted lines in
Figure 5. Figure 6 shews the armature core in section, the central portion being
left hollow, as shewn, while the iron wire W forms a hollow curved shell. Instead
of the wire W rings or bars of iron, which when fitted together give the required
outline, may be used, the various pieces being preferably insulated from one another.
Considerable latitude in the construction of the iron armature core used in this
Invention may be exercised, since the said core is not alone dependent for its
magnetization upon the induced magnetism it receives from the field magnet poles,
but is directly magnetized by the field magnet coils C, C¹, Figure 1, which surround
the said armature.

page_text: Upon the armature core, shewn in Figures 4, 5, and 6, it is not difficult to wind
insulated wire so as to obtain a nearly spherical outline, small projections upon
the edges of the plates D, D, Figure 4, tending to keep the convolutions in place.
The number and connections of the coils on the armature will vary according to
the form and arrangement of the commutator or the purpose to which the current
developed is to be applied, and it is not intended therefore to limit the present
Invention to any particular arrangement of the coils on the armature.
however a special winding of wire and commutator to be well adapted to the
purposes of my Invention. This special winding and commutator I will now
proceed to describe.
I find
Three coils of insulated wire are wound upon the armature, as shewn in Figures 7
and 8, intersecting one another at the axis X at angles of approximately 60°. The
manner of winding the three coils so as to secure equality in the lengths of wire in
them, and uniformity of outline of the armature, is substantially as follows:-
First, one half of the wire of one of the coils is wound on, then one half of the
second coil is wound, then the whole of the third coil is wound on; next, the
remaining half of the second coil; and, finally, the remaining half of the first coil.
It will thus be seen that portions of the first coil will respectively underlie and
overlie the other two coils where they intersect, and portions of the second coil will
likewise underlie and overlie the third coil.
The connections of the terminals of the three coils will be further described in
connection with Figures 13, 14, 15, and 16, which also shew the arrangement of
the commutator.
If the armature be run for reversed currents no commutation is necessary, but
the ends of the armature coils are carried out in the manner usual in such a case.
Figure 9 is a section intended to elucidate the distribution of inagnetic polarity
in a machine constructed as herein described. The armature core W receives an
inductive action in all directions from the spherical surface of the magnet poles
N and S. It will thus be seen also that no portion of the wire surrounding the
core W can escape the powerful direct action of the field of force from the poles N
and S. In machines as hitherto constructed a considerable portion of the armature
wire has escaped this direct action. In the "Paccinotti," "Gramme," and similar
machines the wire on the interior surface of the ring thus escapes. In the
"Siemens" and similar machines, it is the wire that passes over the ends of the
cylindrical core, and from the overlapping of the numerous coils at the ends of the
cylinder this inactive wire bears a considerable proportion to the rest or active
portion.
In Figure 10 I have shown in section a cylindrical armature similar to those
ordinarily used. N and S are the poles of the field magnets. The portions of the
armature wire at e, e, e, e, do not at any time come under the action of the field
magnet poles N and S. To reduce the loss due to the inactive wire at e to a
minimum, a cylindrical armature is employed, whose length is relatively much
greater than its diameter, thus giving rise to inconvenience of form and diffusion
of magnetic field. Moreover there is no convergence in all directions of the
magnetic force upon the armature, the arrows shewing the general direction of the
inductive action of the field, which is sensibly parallel. In Figure 9 the
distribution of the magnetic polarization induced by the coils C, C, and C', C', in
the poles N and S and in the bars B, B, is shewn by the arrows, both the inner
and outer sides of the magnetizing coils being utilized. This feature enables great
concentration of magnetic force to be obtained.
Besides the convergence of the field of force upon the armature in all directions,
there is yet to be considered the direct magnetizing and inductive action of the
coils C, C, and C, C¹, upon the whole of the armature wire. In Figure 11 the
coils C, C, and C₁, C, are alone shewn as surrounding the armature A, which
revolves in and between them. A powerful current is sustained in the said
coils C, C, and C₁, C₁, from a suitable source of electricity. When the armature A
revolves, currents of considerable strength are induced in the coils of the said

page_text: armature, which currents result mainly from the effect of the coils C, C, and C', C¹,
that give polarity N¹, S¹, to the armature core and also act by direct induction
upon the moving armature coils. It would be sufficient to revolve only the coils
of the armature, allowing the core W to remain stationary, but the practical
difficulties of construction are thereby increased. In illustration of the direct
inductive action of the magnet coils upon the armature coils reference is made to
Figure 12, where a coil C, C, through which an electric current is circulating, has
a shaft X passing transversely through it, which shaft bears several wire hoops
whose planes pass through the axis at angles to one another and correspond to
or represent convolutions of armature wire. If this arrangement be revolved,
currents are set up in the wire hoops, due to direct inductive action of the currents
in the coil C, C.
Figure 13 shews the manner of connecting the terminals of the armature coils;
c¹, c¹, c³, c², c³, c, are the three coils, shewn in outline for clearness. There are six
ends of wire from the three coils. Three of these ends taken alternately are
connected at u, and the remaining three alternate ends are connected singly to
the three insulated segments K', K, K³, of a commutator. One of the ends of the
coil c, c¹, will be connected to the other coils at u, and the other to the segment K¹
of the commutator. Similarly, the other two coils have each a terminal going to u,
and one each also to the segments K2, K³, in the commutator. Care must be
exercised to connect to the segments of the commutator only such terminals as are
alternate or which lead from positions on the circumference of the armature 120°
apart. The segments K1, K2, K³, are made from a copper ring or otherwise, and
constitute a circular conducting ring with slits or gaps at equal distances apart
and completely separating the segments. Strips of copper or other metal S*, S*,
Figure 14, rub upon the surface of the segments K', K2, K, and are supported
in any suitable manner so as to touch at opposite sides of the ring of segments, as
shewn in Figure 14. Their position with respect to the segments is alterable during
operation so as to secure the best position for taking off the currents generated in
the armature wire. Since the seginents on one side of the commutator will always
be of opposite polarity to those on the opposite side, a position is soon found where
the strips or collectors S*, S*, will take off a continuous uninterrupted current of a
strength depending on the size and speed of the machine. This simple arrangement
of parts gives with a low speed a current practically continuous and of great
power. Wires are led from the strips S*, S*, to the point where the electric force
is utilized. This circuit in most cases includes the wire of the coils C, C, and
C¹, C¹, as shewn in Figure 14, in order to magnetize the machine by the currents
generated. The three coils of the armature are shewn separate for clearness in
Figure 14 at c, c², c³.
Figure 15 shews in detail the construction of the commutator. The shaft X
has upon it two flanges D, DI, between which is mounted the segmental ring of
the commutator. Each segment K1, K2, K³, has two rods passed through it or
otherwise fastened to it, and projecting through holes in the flanges D, D', but
insulated from the said flanges by rings or bushings i of vulcanite or wood.
The segments K1, K2, K³, are mounted at some distance from the flanges D, D',
on each side, and their inner diameter is so much larger than the shaft X passing
through their centre as to leave an air space between the segments and the shaft.
This space serves in conjunction with the lateral spaces between the segments and
the flanges D, D', as a most effectual air insulation of the segments from one
another and from the shaft. The insulated wires c1, c2, c, from the armature coils
pass through the shaft and are connected to the ends of one of the rods projecting
from each seginent of the commutator. The slot or gap between any two segments
K³, K, of the commutator is made preferably at a somewhat oblique angle to the
ring, as shewn in Figure 15. The angle may be varied within moderate limits,
but when the radii at the two ends of the slot would differ 20° in angular position
with respect to each other, the obliquity may be considered sufficient.
Figure 16 shews a section through one of the segments and a rod 1 serving as

page_text: its support, similar letters to those of Figure 15 being used to denote similar
parts.
In practising this Invention single, double, or other wires may be wound upon
the magnet cores or armature, and the multiple terminals so provided may be
connected in various ways, in series or in multiple are, or for separate circuits, and
multiple commutators may in like manner be used. These and similar modifications
of circuits will suggest themselves to those versed in the subject.
Besides the many advantages of my Invention from an electrical and economical
standpoint there are several mechanical advantages.
The complete enclosure of the armature by the magnet frame prevents injury to
the said armature by objects being brought into contact with it while revolving.
The magnet poles also being enclosed cannot attract pieces of iron inadvertently
left near the machine and cause injury.
The external iron of the machine serves also as an effective protection to the
magnet coils, preventing injury during shipment or otherwise.
Having thus fully described the said Invention as communicated to me by my
foreign correspondent, and shewn how the same may be conveniently and
advantageously carried into practice, I wish it understood that I do not confine
myself to the exact form and disposition of the parts of the apparatus above
described, as the same may be varied in many ways without departing from the
principle of this Invention. I also wish it understood that, although I have
described my Invention as applicable to the generation of electric currents only, I
may employ it in the conversion of electricity into motive power, and to this latter
use it is admirably adapted by reason of the formn and disposition of its various
parts, and also of the electrical principles involved, and I claim,--
First. In a dynamo-electric machine or apparatus, two magnetizing coils
surrounding the field magnets, and the revolving armature of the machine for the
purpose specified.
Second. In a dynamo-electric machine, two magnetizing coils (which may, if
desired, be combined to form a single coil) directly surrounding the iron cores of
the field magnets, and also the revolving armature, and constituting the sole source
of magnetic field and inductive action in the machine.
Third. In a dynamo-electric machine, the magnetizing coils C, C, and C¹, C',
enclosing or surrounding the field magnet poles N and S, and surrounded or
enclosed by iron bars B, B, or plates uniting the said poles externally, the whole
arranged for the purpose of utilizing the internal magnetizing effect of the said
coils upon the poles, and also the external magnetizing effect of the said coils upon
the bars B, B, substantially as above set forth and for the purposes specified.
Fourth. In a dynamo-electric machine, an armature core of spherical or similar
outline, flattened at the parts where the shaft or axis enters, and placed between
the poles N and S of the field magnets, which also have a corresponding hollow
spherical or similar outline, the said armature core being arranged to revolve on an
axis passing transversely to a line joining the centres of the field magnet poles.
Fifth. In a dynamo-electric machine, an armature core of spherical or similar
outline placed between the poles of the field magnets, as described, the said core
being inductively magnetized by a convergence upon it from all sides of the lines
of magnetic force from the field magnets, and at the same time directly magnetized
by the coils of the field magnets surrounding and enclosing the said armature
core.
Sixth. In a dynamo-electric machine, an armature core wound with insulated
wire to a spherical outline, or nearly so, and enclosed or surrounded as far as
practicable by the field-magnet poles, except at the gaps or spaces through which
the axis or shaft of the armature core passes and which separate the said poles, for
the purpose of placing all the insulated wire of the armature under the direct
influence of the said poles, and thereby avoiding the use of inactive or partly
inactive wire.
Seventh. In a dynamo-electric machine, a spherical enclosed armature consisting

page_text: of an iron core of suitable construction, and insulated wire coils surrounding the
same, and in turn surrounded, as far as practicable, by the field magnet coils for
the purpose of obtaining the maximum inductive effect in the insulated wire of the
said armature.
Eighth. In a dynamo-electric machine, a spherical enclosed armature wound
with a set of three armature-coils, and provided with a commutator consisting of a
set of three insulated segments, substantially as above described.
Ninth. In a dynamo-electric machine, a magnet frame consisting of the hollow
shells N and S, and flanges F, F', and connecting bars B, B, between or connecting
the said flanges, the said bars constituting an outer open surrounding casing, in the
centre of which the armature revolves between the opposing faces of the said
magnet-shells N and S, all substantially as above described and for the purposes
specified.
Tenth. A dynamo-electric generator or motor, in which the following elements
of effective action are severally combined, namely, the magnetizing coils surrounding
and surrounded by iron masses so placed as to utilize both the internal and
external magnetizing effects of the said coils; the magnetizing coils surrounding
and directly magnetizing both the field magnet poles and the armature core; an
enclosed armature wound with insulated wire, upon which a convergence of
magnetic force takes place at the same time from all sides, thus placing the whole
of the insulated wire in a powerful field; and an armature whose coils of insulated
wire are inductively acted upon by the currents in the surrounding field magnet
coils.
In witness whereof, I, the said William Robert Lake, have hereunto set my
hand and seal, this Twenty sixth day of March, in the year of our Lord
One thousand eight hundred and eighty one.