IMPROVEMENTS IN TELEGRAPHY AND TELEPHONY
Year: 1885

page_text: I FRED HARVEY BROWN of Fort Worth, in the County of Tarrant and State of
Texas, in the United States of America, gentleman, do hereby declare the nature of
my invention for "IMPROVEMENTS IN TELEGRAPHY AND TELEPHONY" and in what
manner the same is to be performed to be particularly described and ascertained in
and by the following statement :-
My invention relates to an improvement in magneto telegraphs, and it consists
in the peculiar construction and combination of devices that will be more fully set
forth hereinafter and particularly pointed out in the claims.
My invention has for its object the transmission of telegraphic or telephonic
messages between distant points, by means of induced currents produced by the use
of permanent magnets and without the use of a battery current.
The accompanying drawings represent instruments by means of which I am"
enabled to carry my invention into effect.
Fig. 1, is a side elevation of a sending instrument..
Fig. 2, is a vertical sectional view of a receiving instrument.
Fig. 3 is a horizontal sectional view of the same, taken on the line x-x of
fig. 2.
A, represents the sending instrument which is composed of a permanent,
U-shaped magnet, on the poles of which are wrapped the helices of insulated
wire, B, a key, C, is pivoted to one pole of the magnet; and extends over and
beyond the opposite pole thereof, and is provided at its outer extremity with a
button, D, similar to the telegraphic keys now in common use.
E, represents an adjusting screw, which is made of iron, and passes down
through the key, C, its lower end being normally nearly in contact with the pole, S,
of the magnet.
t
The adjusting screw, E, is provided with a jam-nut, e, as shown.
F, represents a brass screw that projects from the upper side of the, S, pole of
the-helix. On this screw is placed a thumb-nut, f, which is internally threaded to
receive the screw, and which is adapted to be adjusted up and down upon the
screw F
A coiled spring, f', bears between the upper side of the nut f, and the lower side
of the key, and prevents the screw, E, from coming normally in contact with":
the, S, pole of the magnet.
A curved arm, G, is made of brass and is secured to the upper side of the S, helix,
and down through the upper end of this arm is passed a regulating or adjusting:
screw, g, which has a jam-nut, gl, and limits the upward movement of the key.
A brass contact point, a, is provided for the S, pole of the magnet,
I

page_text: H, represents a disc which is preferably made of thin sheet steel, and which is
permanently secured to the pivoted end of the key, and extends horizontally over
the poles of the magnet as shown.
Z, represents the receiving instrument of which I represents an enclosing case
which is composed of wood or metal and is provided with a mouth piece, K.
To the lower side of this case, on its inner side, is secured a permanent, U-shaped
magnet the, S pole of which is at one side of the enclosing case, while the N-pole
is directly in line with the centre of the case and its mouth piece.
•
On the N-pole of the magnet is wound a helix, L, of fine insulated wire, while
the, S, pole is left bare.
The ends of the helix, L are secured to the binding post, M, and the wires from
the sending instrument are connected to said binding posts, as shown.
N, represents a circular metallic band, having projecting points, n.
This band is placed in the enclosing case, in the upper side thereof, at a suitable
distance below the contracted inner end of the mouth piece, and is secured to said
enclosing case by means of screws which pass through openings in the outer ends
of the projecting: points, and secure said points in receivers that are made in the
enclosing case to receive them, as shown in Fig. 3.
By this construction an air space is left between the band and the enclosing
case.
On the underside of the band, N, is secured a disc, O, which is preferably made
of thin sheet steel, and which is accoustically insulated from the band, N, by a
piece of paper or other suitable substance, P, that is interposed between the disc
and its supporting band.
The S-pole of the magnet is in contact with the N-pole, or outer edge of the
magnetized disc, and the N-pole of the magnet is directly under the centre of the
disc and out of contact therewith.
By this construction it will be plain that the centre of the disc, O, is free to
vibrate.
By securing the disc in the enclosing case so as to leave an air space around the
outer side of the disc between it and the inner side of the enclosing case, the
air chamber formed by the enclosing case is in communication in the air space in
that part of the enclosing case above the disc.
The operation of my invention is as follows:-
The key of the sending instrument is operated so as to tap off the dots and
dashes used in the telegraphic code (Morse).
As the key is depressed it comes in contact with the S-pole of the magnet and
thus closes the circuit, and the jar consequent upon this in part sets the disc which
is secured to the key in vibration in consonance therewith and produces a resonant
tone.
The vibration of the sending disc induces an electric current instantaneously of
great energy and intensity, but of short duration, which is transmitted through the
connecting wire to the receiving instrument and the vibrations of the sending disc
are reproduced by the disc in the receiving instrument.
The vibrations of the receiving disc are communicated to the open air in the
enclosing case and this air chamber being in communication with the external air,
the air in said chamber acts as a resonator and conveys clearly to the ear of the
receiving operator the signals made by the sending instrument.
I do not wish to limit myself to the precise construction shown and described, as
it is evident that many modifications may be made therein, without departing
from the spirit of my invention.
+
By placing an enclosing case around the disc at each end of the line. and by
providing their enclosing cases, with suitable mouth pieces, the instruments are
adapted for the transmission of articulate sounds.
'
In Fig. 2 I have shown the receiving instrument with only one helix on its
magnet which is all that is necessary. if the instrument is to be used merely as a

page_text: receiving instrument, but if it is adapted for use both as a sending and receiving
instrument, or as a sending instrument its magnet will be provided with two coils.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is
1. The combination of a permanent magnet having a coil or coils, of an
armature or disc connected to one pole thereof and free to vibrate over the opposite
pole, and a key for vibrating the armature or disc, substantially as described.
2. The combination of a permanent magnet having a coil or coils, an armature or
disc connected to one pole thereof, and free to vibrate over the opposite pole, a key
for vibrating the armature or disc, and stops for limiting the play of the key,
substantially as described.
3. The combination of a permanent magnet having a coil or coils, an armature
or disc connected to one pole thereof and free to vibrate over the opposito pole, a
key for vibrating the armature or disc, and a spring for keeping the key normally
out of contact with the disconnected pole substantially as described.
4. The combination of a permanent magnet having a coil or coils an armature or
disc connected to one pole thereof and free to vibrate over the opposite pole a key
for vibrating the armature or disc a spring for keeping the key normally out
of contact with the disconnected pole and stops for limiting the play of the key
substantially as described.
5. The combination of the permanent magnets having the coils connected in
circuit an armature or disc connected to one pole of each magnet and free to
vibrate over the opposite pole thereof whereby the vibrations of one of the
armatures or discs are transmitted by induced currents to the other armatures
or discs in circuit and reproduced by said other armatures or discs and enclosing
case forming an air chamber around the disc or armature of one or each of the
connected magnets, said enclosing case having a mouth piece substantially as
described.
6. The combination of the permanent magnets having the coils connected in
circuit an armature or disc connected to one pole of each magnet and free to vibrate
over the opposite pole thereof whereby the vibrations of one of the armatures or
discs are transmitted by induced currents to the other armatures or discs in circuit
and reproduced by said other armatures or discs an enclosing case forming an air
chamber around the disc or armature of one or each of the connected magnets said
case or cases having a mouth piece and a key or keys for vibrating the armature
or discs of one or each of the magnets in circuit substantially as described.
7. The method of and apparatus for transmitting vocal or other sounds as
hereindescribed which consists in disturbing the magnetic tensions of a permanent
magnet by vibrating an armature over its poles causing electrical pulsations in
helices of wire wound around the poles of the said magnet which pulsations are
reproduced in the helix of another inagnet connected in circuit with it which
electrical pulsations disturb the magnetic tension of the receiving magnet and
cause the diaphragm of this magnet to be deflected in harmonious vibrations with
the disturbing diaphragm the number of convolutions of wire in the sending
instrument being greater in than in receiving instrument.