IMPROVEMENTS IN THE MEANS OF OBTAINING AND APPLYING MAGNETO- ELECTRIC CURRENTS, AND APPARATUS THEREFOR
Year: 1872

page_text: LETTERS PATENT to Charles William Siemens, of No. 3, Great George
Street, Westminster, in the County of Middlesex, for the Invention
of "IMPROVEMENTS IN THE MEANS OF OBTAINING AND APPLYING MAGNETO-
ELECTRIC CURRENTS, AND APPARATUS THEREFOR.”—A communication from
abroad by Werner Siemens, of Berlin, in the Empire of Germany.
Sealed the 23rd August 1872, and dated the 25th June 1872.
PROVISIONAL SPECIFICATION left by the said Charles William
Siemens at the Office of the Commissioners of Patents, with his
Petition, on the 25th June 1872.
I, CHARLES WILLIAM SIEMENS, of No. 3, Great George Street, West-
minster, in the County of Middlesex, do hereby declare the nature of
the said Invention for "IMPROVEMENTS IN THE MEANS OF OBTAINING AND
APPLYING MAGNETO-ELECTRIC CURRENTS, AND APPARATUS THEREFOR," to be as
follows:-
If an electro-magnet, or a permanent magnet which may be furnished
with polar extensions or armatures, is so constructed that the two polar
surfaces, which should be of considerable superficial area, are opposed to

page_text: each other with only a very narrow intervening space, it will be found
that the magnet in question, however powerfully excited or charged, will
exercise little or no magnetic influence upon surrounding objects, but
will be in the condition almost of a closed magnet. On introducing,
however, a portion of an electric circuit into the narrow space between
the polar surfaces, and moving it to and fro, electrical currents will be
set up
in the circuit of an intensity depending upon the total magnetism
of the magnet employed, and upon the amount of polar surface over
which the circuit is moved. The portion of the circuit being coiled in
such a manner that the whole space between the polar surfaces is
filled with it, and motion being imparted to the same, it is possible to
obtain currents of considerable intensity.
A convenient arrangement for this purpose consists in piercing one of
the poles or polar extensions of the maguet, and causing the second pole
to enter the cavity of the first, so that only a narrow annular space is
left between the two polar surfaces for the reception of a conducting
coil. By moving this coil to and fro in the space, a comparatively
strong electric current will be produced in the circuit of which the coil
forms a part, which current may be employed for moving telegraphic
apparatus, or for any other purpose for which electric currents are avail-
able. If, instead of imparting mechanical motion to the coil, a current
of electricity is directed through the same, a force will instantly be pro-
duced tending to move the coil to or fro, according to the direction of
the current, which motion can be made available for moving mechanism.
The dynamo-electrical current generated in the one case, and the
mechanical force produced in the other, may be increased by com-
bining several magnets, and working coils into one system. The current
produced in the former case may be intensified, moreover, by directing
the dynamo current of one or more magnets through the coil or coils of
a second series.
In working telegraphic apparatus through long submarine or land
lincs, it is of importance to obtain the effect from the least possible
amount of current. For this purpose a coil of very fine conductor may
be suspended by means of a spring or otherwise in the annular polar field
of a powerful electro or permanent magnet, when a very slight current
passing through the line wire and the suspended wire will cause decided
motion of the latter in the one direction or the other, according to the
direction of the current employed. The motion thus obtained may be

page_text: "
applied for working recording apparatus, for releasing detents, or for
moving optical signals; but if it is intended to work through line wire
of extreme length, it is preferable to use the motion of the coil
for relays or making electrical contacts for the establishment of local
circuits.
In order to prevent tremulous motion of the coil, which might produce
uncertain contacts, the moving coil may be surrounded by a cylinder of
thin metal (by preference, aluminium), which tends to moderate and
retard without preventing the movement. A dash pot or oil cylinder
may be applied for a like purpose. In order to diminish the inertia of
the moving coil it may be made of aluminium.
By a modification of the magnetic arrangement, the moving coil may
be made to surround a ring or annulus connected by a strong stem with
one pole of a magnet, while the other pole of the magnet forms a central
stud within the annulus, and also a ring-shaped extension surrounding
the same. The coil is in this case supported from a central axis, so
arranged that a partly rotative motion may be imparted to it meclia-
nically, in which case electrical currents will be produced in the coil,
or that motion may be induced in it by alternating currents directed
through the coil.
:
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Charles William Siemens in the Great Seal Patent
Office on the 24th December 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
WILLIAM SIEMENS, of No. 3, Great George Street, Westminster, in the
County of Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-fifth day of June, in the year
of our Lord One thousand eight hundred and seventy-two, in the thirty-
sixth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Charles William Siemens, Her special
license that I, the said Charles William Siemens, my executors, admi-
nistrators, and assigns, or such others as I, the said Charles William
Siemens, my executors, administrators, and assigns, should at any timo

page_text: agree with, and no others, from time to time and at all times thereafter
during the term therein expressed, should and lawfully might make, use,
exercise, and vend, within the United Kingdom of Great Britain and
Ireland, the Channel Islands, and Isle of Man, an Invention for "IMPROVE-
MENTS IN THE MEANS OF OBTAINING AND APPLYING MAGNETO-ELECTRIC CURRENTS,
AND APPARATUS THEREFOR," a communication to me from abroad by Werner
Siemens, of Berlin, in the Empire of Germany, upon the condition
(amongst others) that I, the said Charles William Siemens, my exe-
cutors or administrators, by an instrument in writing under my, or
their, or one of their hands and seals, should particularly describe
and ascertain the nature of the said Invention, and in what manner the
same was to be performed, and cause the same to be filed in the Great
Seal Patent Office within six calendar months next and immediately
after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Charles William Siemens, do hereby
declare the nature of the said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained
in and by the following statement thereof, reference being had to tho
accompanying Drawings, and to the figures and letters marked thereon,*
that is to say :-
If an electro-magnet, or a permanent magnet which may be furnished
with polar extensions or armatures, is so constructed that the two polar
surfaces, which should be of considerable superficial area, are exposed to
each other with only a very narrow intervening space, it will be found
that the magnet in question, however powerfully excited or charged,
will exercise little or no magnetic influence upon surrounding objects,
but will be in the condition almost of a closed magnet. On introducing,
however, a portion of an clectric circuit into the narrow space between
the polar surfaces, and moving it to and fro, electrical currents will be
set up in the circuit of an intensity greatly depending upon the total
magnetism of the magnet employed, and upon the amount of polar
surface over which the circuit is moved, the portion of the circuit being
coiled by preference in such a manner that the whole space between the
polar surfaces is filled with it, and motion being imparted to the same it
is possible to obtain currents of considerable intensity.
A convenient arrangement for this purpose consists in piercing one of
the poles or polar extensions of the magnet, and causing the second pole

page_text: to enter the cavity of the first, so that only a narrow annular space is
left between the two polar surfaces for the reception of a conducting
coil. By moving this coil to and fro in the space, a comparatively strong
electric current will be produced in the circuit of which the coil forms a
5 part, which current may be employed for moving telegraphic apparatus,
or for any other purpose for which electric currents are available. If,
instead of imparting mechanical motion to the coil, a current of elec-
tricity is directed through the same, a force will instantly be produced
tending to move the coil to or fro, according to the direction of the
current, which motion can be made available for moving mechanism.
The dynamo-electrical current generated in the one case, and the
mechanical force produced in the other, may be increased by combining
several magnets and working coils into one system. The current pro-
duced in the former case may be intensified, morcover, by directing
the dynamo current of one or more magnets through the coil or coils of
a second scries.
In working telegraphic apparatus through long submarine or land
lines, it is of importance to obtain the effect from the least possible
amount of current. For this purpose a coil of very fine conductor may
be suspended by means of a spring or otherwise in the annular polar field
of a powerful electro or permanent magnet, when a very slight current
passing through the line wire and the suspended coil will cause decided
motion of the latter in the one direction or the other, according to the
direction of the current employed. The motion thus obtained may be
applied for working recording apparatus, for releasing detents, or for
moving visible or audible signals; but if it is intended to work through
line wire of extreme length, it is preferable to use the motion of the coil
for relays, or making electrical contacts for the establishment of local
circuits.
In order to prevent tremulous motion of the coil, which might produce
uncertain contacts, the moving coil may surround or be surrounded by
a cylinder of thin metal (by preference, aluminium), which tends to
moderate and retard without preventing the movement.
By a modification of the magnetic arrangement, the moving coil may

page_text: the same. The coil is in this case supported from a central axis, so
arranged that a partly rotative motion may be imparted to it mecha-
nically, in which case electrical currents will be produced in the coil,
or that motion may be induced in it by alternating currents directed
through the coil.
Figure 1 represents part of a longitudinal section, Figure 2, part of a
transverse section, and Figure 3 represents a plan of one form of
apparatus constructed according to this Invention.
S is one pole of a permanent or electro-magnet, and N is the other
pole to which is attached, as a polar extension, an iron plate N'. This
plate is pierced with a cylindrical hole, into which is inserted the pole or
polar extension S. O is a coil of electric conducting wire suspended in
the annular space between S and N' by means of wire springs A, which
serve also as conductors. These wires are inserted insulated in a rocking
bar B pivotted at each end, and provided with an arm D having a spring
and set screw, by which it can be caused to rock a little either way, and
thereby to adjust vertically the position of the coil C. The two outer
wires A, A, are connected by conductors, the one to one pole of a battery,
and the other to the other pole; or the one to a line of telegraph wire,
and the other to the return wire, or to earth; and they serve as con-
ductors, the one to one end of the coil wire C, and the other to the other
end of the same. The middle wire A serves as a conductor to the
metallic body of the coil C. When a current of electricity is passed
through the wire of the coil C, the coil is caused to move either upwards
or downwards, according to the direction of the electric current and the
polarity of the magnet within the annular space between its polar
extensions, and alternating currents cause the coil to vibrate up and
down. Or, if the coil be caused to vibrate by mechanical means, a series
of alternating electrical currents will be generated in the wires of the
coil and the conductors to and from them. These currents may be used
either. directly to work known electrical apparatus, or they may be
directed through the coils of electro-magnets to produce or intensify
magnetic force, and such magnets may themselves be used to work coils
as above described. If currents so produced from the movement of a
coil in the field of a weak magnet were directed through the coils of that
magnet, the magnet would thereby be strengthened, its action on the

page_text: coil would be intensified, and the stronger current thus produced would
further strengthen the maguet.
'
:
The movement of the coil C produced by passing a current of elcc-
tricity through its wire may be utilized for working recording apparatus,
for releasing detents, or for moving visible or audible signals. One.
mode of effecting this will be understood by reference to Figure 2, in
which Figure the upper part of the hoop O' attached to the coil C is
provided with contact pieces on its upper and lower sides. Above and'
below these are contact pieces E and E³, mounted so that they can be
accurately adjusted in level by means of setting screws. From the
hoop C¹ a conducting wire F, partly formed by the middle wire spring A,
is led to one pole of a battery f, or other source of electricity from the
other pole, of which a conductor F¹ is led to a commutator G. From
the contact pieces E and E¹ conducting wires lead to a commutator G¹
which allows of their being connected together, or connected each to a
separate circuit 9, 9', which unite at G.
It will be seen that if the coil C be caused to rise, as above described,
by the passage of a current through its wire, contact will be made at E,
and the circuit ƒ, F, C³, Ẹ, G¹, g, G, F', will be established. If on the
other hand the coil C be caused to descend, the circuit f, F, C', E¹, G',
g', G, F', will be established. If, therefore, any of the known instru-
ments worked by electricity were placed in the circuits g and g¹ they
would be worked by the battery f whenever their respective circuits were
established as above described. Two separate instruments, or a duplicato
instrument, could thus be worked from the battery ƒ by alternating
currents passed through the wire of the coil C. Or, the two conductors
leading from E and E¹ might be led to one instrument by setting the
commutator G¹ so as to join them, and thus a series of currents, alter-
nating in direction in a line wire, may be made to produce a series
of intermittent currents of one direction in an instrument; and these
intermittent currents may be made to succeed so rapidly as to constitute
virtually a continuous current.
By arranging and constructing the apparatus as above described, it
will be found that when no current is sent through the wire of the coil O,
this coil will remain in a position of rest, to which it will return after
the cessation of currents sent through it, whatever may have been their
number, direction, or intensity, and the contacts E and E' may be

page_text: adjusted so as to be equidistant from C' when it is in the position of
reposc.
In order to prevent tremulous motion of the coil C, which might pro-
duce uncertain contacts at E and E', the wire of the coil C is wound on
or is enclosed in a metallic cylinder, which by preference is made of
aluminium.
•
Figure 4 represents to an enlarged scale a section of a coil wound upon
a cylinder of thin metal, and Figure 5 represents it wound upon such a
cylinder, and also covered by one outside. The metal so applied acts as
a damper.
G
Figure 6 represents part of a vertical section; and Figure 7 represents
an end view of apparatus in which the coil C is suspended by four fila-
ments H, H (which may be of silk or other light flexible material), in the
annular space between the pole S and the extension N of the pole N.
The filaments H, H, are attached to pins which can be turned to adjust
their length, and thus bring the coil C into proper position. In this
case the coil has projecting from it a bent arm C', which performs the
shme function as has been described above with reference to the hoop C¹
in Figure 2. The circuits in Figure 6 are analogous to those shewn in
Figure 2, and corresponding parts are marked with the same letters in
both Figures 2 and 6. By this mode of suspending the coil an extremely
sensitive action of it is obtained, its natural tendency being to assume
its middle position.
The arm C (Figure 6) projecting from the coil C may be made to
furnish visible signals by the movement of the coil. For this purpose
there may be attached to it a thin screen of light material, such as is
represented at I, in Figure 8. By making in this screen a slot such as is
shewn in Figure 8, and placing behind it a vertical line of light, and in
front of it an eye hole or piece, when the screen is in its middle position
a line of light will be seen, when it is moved to the right two bright
points will be seen, onc above the other, and when it is moved to the
left one bright middle point only will be seen.
It is obvious that screens having slots of other forms might be employed
to shew the position of the coil by distinctive marks of the light passing
through them.
Figure 9 represents diagrammatically part of a section, and Figure 10
a wlan of an encament whovahu a coil is made to travel in n oivoulan

page_text: into a ring N' surrounding the other pole S. On the ring N₁is placed
vertically, and so fitted to the ring N¹
When a current of electricity is passed
a coil K having its wire coiled
that it can slide freely thereon.
through the wire of the coil K in one direction, the coil will move round
the ring N¹ in the direction of the arrow. When the direction of the
electrical current is reversed, the coil K will move round the ring in the
opposite direction; or, if the coil K be moved by mechanical means along
the ring N', an electrical current will be set up in the wire of the
coil.
The Figures 9 and 10, last referred to, shew diagrammatically how the
movement of a coil in the magnetic field may be in a circular path
instead of a rectilinear path as in the Figures previously referred to.
Figure 11 represents part of a section of apparatus whereby cither a
current of electricity may impart to a coil an oscillating rotary motion,
or the oscillating rotary motion of a coil may set up electrical currents
in its wire. In this case the one pole of a magnet N is connected to a
ring N', and the other pole carries a stud S and a ring-shaped exten-
sion S'. Round the ring N' there is a coil with wires coiled vertically
round an ebonite or other non-magnetic ring mounted on a vertical
axis L. One end of the wire of the coil K communicates through the
axis L and its lower bearing with a conductor O, while the other end of
the coil wire is led insulated along the axis L to the other conductor M.
The axis L, and the coil K attached to it, may be made to rock, in
which case electrical currents will flow through the conductors O and M,
or alternating currents being sent through the conductors O and. M, the
axis Land coil K will be caused to rock.
In the several forms of apparatus described above it will be seen that
the magnetic field, that is to say, the surface of the pole and of the polar
extension which acts on the coil, is made to extend somewhat beyond
the coil itself; the efficacy of the apparatus being thus augmented.
Having thus described the nature of this Invention, and in what
manner the same is-to be performed, as communicated to me by my
foreign correspondent, I would have it understood that I do not claim
generally the arrangement of an electrical coil in a magnetic field for the

page_text: purpose of producing movement of the coil by the transmission of elec-
trical currents through it; but I claim,―
First. The use of apparatus constructed and arranged substantially as
described with reference to Figures 1, 2, and 3, whereby currents of
electricity transmitted through a coil suspended in a magnetic field are 5
made to impart movement to that coil, or whereby, when the coil is
moved in the magnetic field, currents of electricity are generated in
its wires.