IMPROVEMENTS IN TELEPHONES
Year: 1881

page_text: LETTERS PATENT to Edward Willoughby Anderson, of the City of
Washington, in the District of Columbia, United States of North America,
Lawyer, for an Invention of IMPROVEMENTS IN TELEPHONES." A com-
munication by John Goodman, of Louisville, in the County of Jefferson,
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PROVISIONAL SPECIFICATION left by the said Edward Willoughby.
Anderson at the Office of the Commissioners of Patents on the 23rd February
1881.
EDWARD WILLOUGHBY ANDERSON, of the City of Washington, in the District of
Columbia, and United States of North America, Lawyer. "IMPROVEMENTS IN
TELEPHONES." A communication by John Goodman, of Louisville, in the County
of Jefferson and the State of Kentucky, United States of North America, Physician.
This Invention has relation to telephone-receivers, and it consists in the con-
struction and novel arrangement, in combination, of a magnet or series of magnets
and a flattened helix or coil of wire so related to each other that when a current of
electricity is passed through the coil the magnet or magnets will have a tendency
to assume a position at right angles to the direction of the current; and in con-
nection therewith it consists also of elastic devices exerting pressure on the magnets
and tending to maintain them in a position approximating parallelism with the
longitude of the helix.
With this instrument sound is reproduced simply by variations in the force of
the electric current, these variations varying from the full force thereof down to
zero. If the instrument be applied to the ear and the circuit suddenly closed by
metallic connections, the current in the coil will overcome the tension of the spring,
and the points of the magnets will be deflected, and this movement being propa-
gated to the diaphragm or resonator by means of a cord, this diaphragm will be
suddenly relaxed or retracted (according to the direction of the current), as if
struck by a blow, and a short and sharp sound or click will be heard. If,
however, one of the connections be a slightly roughened surface, and the other

page_text: made of hard steel, when the latter is drawn slowly over the former a dull rasping
sound will be heard; but if the passage of the one over the other be made by a
quick movement the vibrations of the diaphragm will cause a continuous sound on
a high key resembling a shriek. These illustrations represent the extremes caused
by making or breaking the circuit, and between them will be readily given forth
by this instrument every degree of character and intensity of sound caused by the
variations in the force of the current.
Every variation in intonation and pitch in the sound depends upon the character
and frequency of the vibrations of the diaphragm, and these, in turn, in this
instrument are due to variations in the force of the current which passes through
the coils, by which the magnets are deflected.
In this instrument, instead of using two helices, a single coil may be employed,
and the magnet or magnets related to the external surface of one side of it; or the
magnet or magnets may be placed within the coil longitudinally, and instead of
using an extraneous spring or elastic band to hold the magnets in parallel relation
with the wires of the helices the magnets themselves may be made in part flexible
or elastic so as to constitute a spring and magnet in one piece.
When the magnets are situated and restrained as above described, and a current
of electricity is passed through the coils, the magnets will be deflected toward a
position at right angles to the length of the coils to an extent in proportion
inversely to the strength of the springs, and directly to the strength of the
current.
If the current is steady the magnets will remain stationary at a point where
the antagonizing forces exerted by the elastic pressure on the one hand and the
electricity on the other are in equilibrio; but if the current be intermittent or
variable in strength during the moments of its cessation or weakness, the elastic
pressure will draw the magnets toward a parallelism with the conductor, and
during its action or increment it will prevail over the elastic pressure and cause
more or less departure of the magnets from this parallelism, thus throwing them
into vibrations, which, if of proper frequency and if imparted to a diaphragm or
resonator, will produce sound.
In using this receiver any transmitter which varies the force of the electric
current sufficiently will answer.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Edward Willoughby Anderson in the Great Seal Patent Office
on the 15th July 1881.
EDWARD WILLOUGHBY ANDERSON, of the City of Washington, in the District
of Columbia, United States of North America, Lawyer. "IMPROVEMENTS IN
TELEPHONES." A communication from John Goodman, of Louisville, in the
County of Jefferson and State of Kentucky, United States of America.
The present Invention has relation to that class of instruments, by means of
which, sounds, articulate or otherwise, are produced or reproduced through the
agency of electricity at a distance from the transmitting station. The Invention
consists mainly in so arranging a magnet or series of magnets in combination with
one or more resonators or diaphragms, and one or more conductors of electricity or
helices, that when a current of electricity is passed through the conductor or con-
ductors it will effect a change of position of the magnet or magnets, and as a result
the diaphragm or diaphragms will be thrown into vibration.
In carrying out the principle upon which my Invention is based I design in
some instances to connect the diaphragm or resonator to the magnet or magnets by
flexible connections, combined with elastic devices, exerting pressure on the
magnets, and tending to maintain them in a position approximating parallelism
with the longitude of the helices, while in other cases inflexible connections may
be made between the magnet or magnets and the diaphragm, and the elastic
devices dispensed with. In the accompanying Drawings I have designed to
illustrate several forms of application of the principle stated, commencing with the
construction in which the elastic devices are used. The letter D represents the
magnets, which in this instance are long and tongue like in form, and are fastened
at intervals by one end to the post H, which is located at the side of the case near
one end of the helix or helices C. In this construction two flattened helices are
employed, their long sides being parallel with each other, and one being a left
hand, while the other is a right hand helix. These helices are designed to effect
the magnets between them in the same manner that a single coil would if it
surrounded them, and a single coil may therefore be employed with like effect.
The magnets D extend between the coils C, and parallel to the wires thereof, sub-
stantially in the manner shown in the Drawings, and the extremities of the
magnets opposite to the post H are left free to move. B indicates the resonator or
diaphragm, made of thin metal or other suitable material. A designates the ear
piece over the resonator, and E a cord or other connection extending from the
resonator to the spring F, which is designed to be connected to the case at the
opposite end from the resonator. In its course the cord E is connected to the middle
portions of the magnets D, which are therefore in a manner strained or held in
tension between two elastic devices, the resonator and the spring F, which tend to
hold said magnets parallel with the wires of the coils C. This tension may be
regulated by means of an adjustable screw G, to which the spring F is
connected.
This instrument is designed to reproduce sound simply through variations in the
force of the electric current, these variations varying from the full force thereof
down to zero. If the instrument be applied to the ear, and the circuit suddenly
closed by metallic connections, the current in the coil will overcome the tension of
the spring, and the points of the magnets D will be deflected, and this movement
being propagated to the diaphragm or resonator by means of the cord E, said
resonator will be suddenly relaxed or retracted (according to the direction of the
current) as if a blow were struck upon it, and a short and sharp sound or click

page_text: will be heard. If however one of the connections be a slightly roughened surface,
and the other made of hard steel, when the latter is drawn slowly over the former
a dull rasping sound will be heard; but if the passage of the one over the other be
made by a quick movement, the vibrations of the diaphragm will cause a continuous
sound on a high key. These illustrations are designed to represent the extremes
caused by making or breaking the circuit, and between them will be given forth
by this instrument every degree of intensity and character of sound caused by the
variations in the force of the current. Every variation of intonation and pitch in
sound depends on the character and frequency of the vibrations of the diaphragm, and
these in turn in this instrument are due to variations in the force of the current
which passes through the coils by which the magnets are deflected. Instead of
using two helices, a single coil may be employed and the magnet or magnets
related to the external surface of one side of it; or the magnet or magnets may be
placed within the coil longitudinally. Instead of using one extraneous spring or
elastic band to hold the magnets in parallel relation with the wires of the helices,
the magnets themselves may be made in part flexible or elastic, so as to constitute
a spring and magnet in one piece. When the magnets are situated and restrained
as above described, and a current of electricity is passed through the coils, the
magnets will be deflected toward a position at right angles to the length of the
coils to an extent, in proportion, inversely, to the strength of the springs and
directly to the strength of the current. If the current is steady the magnets will
remain stationary at a point where the antagonizing forces exerted by the elastic
pressure on the one hand, and the electricity on the other, are in equilibrio; but if
the current be intermittent or variable in strength during the movements of its
cessation or weakness, the elastic pressure will draw the magnets toward a
parallelism with the conductor, and during its action or increment it will prevail
over the elastic pressure and cause more or less departure of the magnets-from this
parallelism, thus throwing them into vibrations, which, if of proper frequency, and
if imparted to a diaphragm or resonator will produce sound. In using this receiver
any transmitter which varies the force of the electric current sufficiently will
answer.
In some of the practical instruments involving the principle of this Invention I
design to dispense with the use of spring pressure on the magnets, and in Figure 5
of the Drawings a diagrammatic representation of the simplest form of such an
instrument is presented. The letter G indicates a sectional view of a flattened
belix. K is a magnet pivoted at its centre, the pivot being passed through a hole
in the centre of the helix. L is a diaphragm or resonator, and R is a delicate rod
connecting the diaphragm to the magnet. It is apparent that the different parts
of this instrument may vary in regard to their relative position without affecting
the fundamental principles of its construction. For instance, the diaphragm may
be placed over the middle of the magnet and may be connected at its centre with
each extremity of said magnet, or the magnet may be pivoted at one end instead
of at the centre.
In Figure 4 I have represented a sectional view of a more complete form of the
instrument. The letter N indicates a case of wood, rubber, or composition.
P represents a flattened helix. S and S¹ are magnets arranged in two series with
opposite poles towards the central line of the helix. T and T¹ are ear pieces, and
V and V¹ are diaphragms, one at each end of the instrument. Z indicates. a
connecting rod, cord, or wire, extending from one diaphragm to the other, to which
the magnets are attached at the central line of the helix. The second diaphragm
being actuated synchronously with the first, and the movements being in the same
direction, the sound is thereby intensified.
Having described this Invention, what I claim and desire to secure by Letters
Patent is,―
1. The means and devices herein before described, whereby sounds, articulate or
otherwise, are produced or reproduced, substantially as specified.
2. In a telephonic receiver, the combination with a conductor or helix, and a

page_text: diaphragm or resonator, of one or more vibratory magnets parallel with the helix
and tending to assume a position at right angles thereto when a current of
electricity is passed through said helix, substantially as specified.
3. The combination with a diaphragm or resonator, and a helix or conductor, of
a vibratory magnet parallel with said conductor and tending to assume an angular
relation thereto under the influence of the current, of elastic connections designed
to hold the magnet in a position approximating parallelism with said conductor,
substantially as specified.
4. The combination with the helices or conductors, and the vibratory magnets
arranged parallel therewith, of the resonator or diaphragm connected mechanically
with the magnets, and the spring or elastic device tending to hold the magnets
parallel with the conductors, and in strained connection with the resonator,
substantially as specified.
5. The combination of a diaphragm or resonator with a magnet so situated with
reference to a conductor of electricity or helix that when a current is passed
through the latter the magnet will tend to assume a position at right angles
therewith, and mechanical connection between the resonator and the magnet,
having no other elastic support than such as is derived from the resonator,
substantially as specified.
6. The combination with the helices and conductors and the magnets of two
diaphragms or resonators arranged one at each end of the instrument and
connected mechanically with the magnet or magnets and with each other,
substantially as specified.
In witness whereof, I, the said Edward Willoughby Anderson, have hereunto
set my hand and seal, this Fourteenth day of July, in the year of our
Lord One thousand eight hundred and eighty one.
EDWARD WILLOUGHBY ANDERSON. (L.S.)