IMPROVEMENTS IN ELECTRO MAGNETIC AND MAGNETO ELECTRIC MACHINES
Year: 1878

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields, in the
County of Middlesex, Gentleman, for the Invention of "IMPROVEMENTS
IN ELECTRO MAGNETIC AND MAGNETO ELECTRIC MACHINES." A communi-
cation from abroad by Emile Bertin and Francois Ernest de Mersanne, both
of Paris in the Republic of France.
Sealed the 27th May 1879, and dated the 11th December 1878.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson at the
Office of the Commissioners of Patents on the 11th December 1878.
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN ELECTRO MAGNETIC AND MAGNETO-ELECTRIC
MACHINES." A communication from abroad by Emile Bertin and Francois Ernest
de Mersanne, both of Paris, in the Republic of France.
This Invention relates to improvements hereinafter described in the construction
and arrangement of dynamo-electric machines (otherwise designated electro-magnetic
machines) and of magneto electric machines.
According to this Invention the inductors are each formed by two coils arranged
end to end so as to form straight electro magnets, having poles N, S, of opposite
denominations at each extremity. These magnets are carried upon the circum-
ference of a plate or disc which may be made of metal or other materials, to which
they are attached at the neutral point midway between the two coils.
metallic plate is used it may be either magnetic or not as desired. The mode of
attaching the magnets is very simple, consisting of a cap piece embracing the core
at the centre and which is screwed to the plate or disc.
When a
The coils in which electricity is to be induced are attached to two external plates
not necessarily metallic, opposite the inductors, which are arranged in such a
manner as to present negative and positive poles (N, S, N, S,) alternately on both
sides.
.

page_text: In order to utilise more advantageously the action of the poles of the coils in
which the electricity is to be induced when they are placed opposite an inducting
coil it is proposed to couple the former together in pairs, consecutively or otherwise,
by means of an iron plate so as to convert them into horse shoe magnets, of which
the iron plate forms the bow. If the coils were not coupled together the action of
the pole nearest to the side of the machine would be unutilized, whereas by coupling
these coils together in pairs suitably selected this action is rendered available in
supplementing the power of the second coil of the electro magnet thus constituted.
The inducting current conducted to the machine by a wire passes first through
two frictional contact makers into a disc with which the said contact makers are
maintained in contact by means of a spring, and the current thence passes to the
inducting coils. The induced currents are carried away by suitable conductors.
In lieu of forming a complete electro magnet by connecting two straight cores by
means of a piece of soft iron, a single core may be employed, bent so as to form two
right angles and completely covered with wire; in this case each induced pole will
be constituted by one of the poles of the core and by the adjacent pole of the next
core, with which it is connected by a soft iron cheek.
In certain cases however the two adjacent poles of the cores may be magnetically
separated by interposing an insulating plate.
It is proposed to make the cores of the inducting coils or of the coils in which the
current is induced or both, tubular or split and composed of separate parts, or they
may be of any other suitable form.
When split cores are used the pieces composing the core of the coil in which the
current is induced.may in this case be arranged parallel to the radius of the coil, and
the pieces composing the cores of the coils for inducing the current may be
arranged at right angles to this direction, or in any other suitable manner.
The cores of the coils in which the current is induced may also be formed by a
thin tube fitted with iron wire.
The relative positions of the coils in which the currents are induced and of the
inducting coils may be reversed by employing such arrangements of detail (as for
example multiple friction rings) as may be necessary to cause the currents to pass
in the proper direction.
The composite inductors employed in this system of insulated coils may then be
coupled together in pairs so as to form complete electro-magnets, as hereinbefore
described with reference to the coils in which the currents are induced.
This mode of construction enables the machines to be constructed with any
number of plates or discs arranged side by side, as may be required, in order to
obtain the desired power.
The electro magnets for inducing electricity and in which electricity is induced,
arranged according to the principle hereinbefore referred to, and with the cores of a
form analogous to those hereinbefore described, may be further modified in the
following manner, the arrangements adopted admitting, according to the winding of
the wire, of uniting two poles of the same denomination by a plate of soft iron or
of retaining the poles of different denominations by not bringing them into
contact.
These electro magnets are intended to be applied two by two on the two surfaces
of a disc of metal or other material, as herein before described, the poles which are
enlarged being placed at a certain distance apart without regard to the respective
denominations of the opposite poles unless it is considered desirable to unite them,
when the poles will be of the same denomination.
This arrangement of the electro magnets admits of two poles being presented
simultaneously or nearly so to the action of induction. The induced electro
magnets are of the same form, and dises carrying induced magnets are arranged
alternately with discs carrying magnets for inducing the current in any desired
number, the two outside discs being necessarily provided with magnets on one side
only.

page_text: The electro magnets employed according to this modification are constructed in
the following manner :-
The cores are fixed to a suitable support and their enlarged poles are arranged at
right angles to the stems of the cores, the cores may also be separated magnetically
from the support by an insulating substance, or they may be placed directly in con-
tact with the support or made in one piece therewith.
These cores may be made straight or they may be curved according to the radius
of the circle of which they form part.
The inductor magnets may be arranged at the extremity of arms fixed to a plate ;
in this case they will rotate, and the coils in which the electricity is induced may
be fixed to a concentric ring of cylindrical form arranged externally or conversely;
the induced magnets may rotate and the inductors may be stationary.
It will be understood that the various forms hereinbefore described will enable
direct or alternate currents to be obtained, and that when permanent magnets are
employed for inducing the current, the machine will become magneto-electric, and
in the latter case the various forins of electro magnets hereinbefore described may
be employed to form the coils in which the current is to be induced.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Henry Johnson in the Great Seal Patent Office on the 11th
June 1879.
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN ELECTRO MAGNETIC AND MAGNET-ELECTRIC
MACHINES." A communication from abroad by Emile Bertin and Francois Ernest
de Mersanne, both of Paris, in the Republic of France.
The said Invention relates to improvements hereinafter described in the construc-
tion and arrangement of electro magnetic machines otherwise designated (dynamo-
electric) machines and of magneto electric machines.
And in order that the said Invention may be fully understood I shall now proceed
more particularly to describe the same, and for that purpose I shall refer to the
several Figures on the annexed Sheet of Drawings, the same letters of reference
indicating corresponding parts in all the corresponding Figures.
Figure 1, Sheet 1, of the accompanying Drawings represents an end elevation,
partly in section, of an apparatus constructed according to the said Invention, and
Figures 2 and 3 are corresponding side elevations of a portion of the same; Figure
4 is a half transverse sectional elevation corresponding to Figure 1, showing the
arrangement of the electro magnets; Figure 5 is a detail showing the mode of con-
ducting the electric current into the apparatus; and Figures 6 to 11 (Sheet 1), and
Figures 12 to 17 (Sheet 2) illustrate various modifications in the construction and
arrangement of the electro magnets and of the cores of the coils in which the current
is to be induced.
The apparatus is supported upon a stand A, provided at each end with a vertical
plate or disc B, of metal or other suitable material, to which are attached coils C,
the cores of which present poles of opposite denominations alternately at N and S.
The stand A also carries bearings D for the reception of a shaft or axis b carrying a
plate or disc b¹, to which are attached a series of electro magnets or inductors E,
presenting poles of opposite denominations alternately at N, S, on both sides of the
disc b¹. These inductors are composed of two cores, provided with coils of wire and
arranged end to end so as to form straight electro magnets having poles N, S, of
opposite denominations at each extremity. These magnets are attached to the
circumference of the disc b' (which may be made of metal or other material), at a
neutral point midway between the two coils by means of a cap piece a embracing
the core at the centre, and which is screwed to the plate or disc b¹.
The coils C in which electricity is to be induced are arranged in such a manner
as to present a series of alternately negative and positive poles (N, S,) facing the
pole S, N, of the inductors E.
In order to utilize more advantageously the action of the poles of the coils C
when they are placed opposite an inducting coil the former are coupled together in
pairs consecutively or otherwise by means of an iron plate e, Figure 3, so as to con-
vert them into horse shoe magnets, of which the iron plate e forms the bow. If the
coils were not thus coupled together the action of the pole nearest to the side of the
machine would be unutilized, whereas by coupling these coils together in pairs
suitabley selected, this action is rendered available in supplementing the power of
the pole of the second coil of the electro magnet thus constituted.
The inducting current conducted to the machine by a wire f passes first through:
two frictional contact makers g, Figure 5, into a disc j, with which the said contact
makers are maintained in contact by means of a spring k and the current thence
passes to the inducting coils E. The currents induced in the coils C are conveyed
away by suitable conductors, not shewn in the Drawings. Figure 6 illustrates two
modifications in the arrangement of the coils or electro magnets in which the current
is induced. In lieu of forming a complete electro magnet by connecting two straight
cores by means of a piece of soft iron, as shewn in Figure 3, a single core k,

page_text: Figure 6, may be employed bent so as to form two right angles and completely
covered with wire, in this case each induced pole, will be constituted by one of the
poles of the core k, and by the adjacent pole of the next core 1, with which it is con-
nected by a plate m of soft irou. In certain cases however the two adjacent poles
of the cores k, l, may be magnetically separated by interposing an insulating plate,
as shown at n.
The cores of the inducting coils or of the coils in which the current is induced,
or both, may be tubular or split, and composed of separate parts, or they may be of
any other suitable form, but it is preferred to construct them as shewn in Figures
7, 8, 9, and 10. According to these arrangements the pieces composing the cores of
the coils in which the current is induced may be arranged, for example, parallel to
the radius of the disc passing through the axis of the coil, and the pieces com-
posing the cores of the coils for inducing the current may be arranged at right
angles to this direction.
The cores of the coils in which the current is induced may also be formed by a
thin tube filled with iron wire, as shewn in Figure 11.
The relative positions of the coils in which the currents are induced and of the
inducting coils may be reversed by employing such arrangements of detail (as for
example multiple friction rings), as may be necessary to cause the current to pass
in the proper direction.
The composite inductors employed in this system of insulated coils may then be
coupled together in pairs_so_as_to_form_complete electro magnets, as hereinbefore
described with refence to the coils in which the currents are induced.
This mode of construction enables the machines to be constructed with any number
of plates or discs provided with magnets, and arranged side by side, as may be
required, in order to obtain the desired power.
Figures 12, 13, 14, 15, 16, and 17, Sheet 2, illustrate various modifications of the
electro magnets for inducing electricity and in which electricity is induced, arranged
according to the principle illustrated in Figures 2 and 3, and with the cores of a
form analogous to that represented in Figure 6, which admit, according to the
winding of the wire, of uniting two poles of the same denomination by a plate of
soft iron, or of retaining the poles of different denominations by not bringing them
into contact.
These electro magnets are intended to be applied two by two on the two surfaces
of a disc of metal or other material, as herein before described. This arrangement
is represented in Figure 12, which is a side view of a part of a disc b', provided
with magnets having enlarged poles M, N; the poles being placed at a certain
distance apart, whether the opposite poles are of the same or a different denomina-
tion, but they may be united when considered desirable in case the poles are of the
same denomination. The induced electro magnets are of the same form, and discs
carrying induced magnets are arranged alternately with discs carrying magnets for
inducing the current in any desired number, the two outside discs being necessarily
provided with magnets on one side only.
The electro magnet represented in Figures 13 and 14 is constructed in the
following manner :-
The cores a, b, are fixed to a suitable support c, and their enlarged poles M and N
are arranged at right angles to the stems of the cores; the cores may also be separated
magnetically from the support c by an insulating substance k, as shown at the end
of the core a, or they may be placed directly in contact with the support, as shewn
at the end of the core b, or may be made in one piece therewith.
These cores may be made straight, as shewn in Figures 13, 14, and 15, or they
may be curved according to the radius of the circle of which they form part, as
shewn in Figures 12 and 16.
The inductor magnets may be arranged at the extremity of arms fixed to a plate;
in this case they will rotate, as shown in Figure 16, and the coils in which the
electricity is induced may be fixed to a concentric ring of cylindrical form arranged

page_text: externally, as shewn in Figure 15, or conversely, the induced magnets may rotate,
as in Figure 16, and the inductors may be stationary, as in Figure 15.
It will be understood that the various forms hereinbefore described will enable
direct or alternate currents to be obtained, and that when permanent magnets are
employed for inducing the current, the machine will become magneto-electric, and
in the latter case the various forms of electro magnets herein before described may
be employed to form the coils in which the current is to be induced.
When a non magnetic disc is employed for carrying the indentors two straight
electro magnets may be connected together at their neutral point, and the polarities
may be reduced as required by the coupling of the coils and the winding of the
wire.
The system thus constituted by the combination of two straight electro magnets
may be replaced by the system illustrated in Figure 17.
Having now described and particularly ascertained the nature of the said Inven-
tion, and the manner in which the same is or may be used or carried into effect,
I would observe in conclusion that what I consider to be novel and original and
therefore claim as the Invention secured to me by the hereinbefore in part recited
Letters Patent is,--
.
First. The arranging of straight electro magnets acting as inducting magnets
on the periphery of a magnetic or non magnetic metallic disc. or plate, substantially
as hereinbefore described.
.
Second. The arranging of the coils in which the current is to be induced in such
a manner that they are coupled together in pairs upon one and the same metallic
disc or plate, substantially as herein before described.
Third. The employment of the electro magnets herein described with reference to
Figures 6, 12, 13, 14, 15, 16, and 17, for the coils in which the current is to be
induced and for the inducting electro magnets, the form of such electro magnets
admitting of the poles of opposite or similar denominations being brought together,
substantially as and for the purposes hereinbefore described.
Fourth. The application of electro magnets or coils with split cores to dynamo or
magneto electric machines, substantially as hereinbefore described.
In witness whereof, I, the said John Henry Johnson, have to this my Specifi-
cation set my hand and seal, this Seventh day of June, One thousand eight
hundred and seventy nine.