Improvements relating to Magnetic Telephony.
Year: 1889

page_text: Date of Application, 6th Feb., 1839
Complete Specification Left, 6th Nov. 1889-Accepted, 7th Dec., 1889
PROVISIONAL SPECIFICATION.
Improvements relating to Magnetic Telephony.
I EUGENE GWOSDEFF of 39 Znamenskaya Street, St. Petersburg in the Empire
of Russia, Gentleman, do hereby declare the nature of this invention to be as
follows:-
The object of this invention is to provide for working telephones by magnetism, and
the invention consists in certain arrangements whereby the best results can be
obtained.
In carrying out this invention, the telephone instruments for transmitting and
receiving the message are slightly modified in construction.
Both, however, consist of an iron diaphragm arranged between two horse-shoe
magnets, the bobbins of which are wound with double wires, one being in communi-
cation with the line, as usual, and the other being short circuited on itself, so that the
resulting current is equal to the sum of the currents induced in each pair.
The iron diaphragm is connected by a non-magnetic rod or rods to a non-magnetic
diaphragm of larger diameter than the iron diaphragm.
In the transmitter, the connection is made by one rod placed at the centre of both
diaphragms. In the receiver, however, I employ two or more rods connected to the
iron diaphragm at the centre, and to the non-magnetic diaphragm at points the
distance of which from the centre is regulated by the difference of the diameter
between the two diaphragms.
I am thus enabled to effect the transmission of words in a loud tone, and without
what I may term distortion of the sound.
Dated this 5th day of February 1889
NEWTON & SON,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements relating to Magnetic Telephony.
I EUGENE GWOSDEFF of 39 Znamenskaya Street, St. Petersburg, in the Empire of
Russia, Gentleman, do hereby declare the nature of this invention and in what manner
the same is to be performed, to be particularly described and ascertained in and by the
following statement :—
The object of this invention is to provide for working telephones by magnetism,
and the invention consists in certain arrangements whereby the best results can be
obtained.
In carrying out this invention, the telephone instruments for transmitting and
receiving the message are slightly different in construction.
Both, however, consist of an iron diaphragın arranged between two horse shoe
magnets, the bobbins of which are wound with double wires, one being in communi-
cation with the line, as usual, and the other being short-circuited on itself, so that the
resulting current is equal to the sum of the currents induced in each pair.
The iron diaphragin is connected by a non-magnetic rod or rods to a non-magnetic
diaphragm of larger diameter than the iron diaphragm.
In the transmitter, the connection is made by one rod placed at the centre of both
diaphragms. In the receiver, however, I employ two or more rods connected to the
iron diaphragm at the centre, and to the non-magnetic diaphragm, at points the
distance of which from the centre is regulated by the difference of the diameter
between the two diaphragms.

page_text: I am thus enabled to effect the transmission of words in a loud tone, and without
what I may term distortion of the sound.
In the accompanying drawing:
-
Figs. 1 and 2 represent in diagram, the principle of construction of the proposed
telephone, Fig. 1 being the transmitter and, Fig. 2 the receiver.-Figs. 3, 4, and 5
represent, by way of example, the construction of a complete apparatus, Fig. 3
being a plan view (the upper half being removed), Fig. 4 a suction on the line I, II.
Fig. 3, and Fig. 5a section on the lino III, IV, Fig. 8.
D is a diaphragm of iron arranged between the poles of two horse-shoo
magnets M MB B and B B' are induction hobbins fixed on the polar extensions
of the magnols M M¹, and are connected together in such a manner that the currents
induced in the bobbins by the movements of the diaphragm D, shall be added the ono
to the other, that is to say, that the resulting current shall be the sum of all the
currents.
The diaphragm ) is placed at such a distance from the two magnets, that ench
exercises an equal attraction on the diaphragm. The sorew ring A, in which the
diaphragm D is fixed by its edge, provides for the exact regulation of the position
of the diaphragm.
In front of the magnets M M', a second diaphragm E is fixed, by its edge, to the
box of the apparatas. This diaphragm E is of a diameter greater than the
diaphragm D, and is made of a non-magnetic material, such as wood, ebonite,
aluminium, or aluminium bronze.
The diaphragm E is connected, by means of an aluminium rod F, to the contre
of the diaphragm D, the rod F passing between the bobbins B B of the upper
magnet M.
If the telephone is to act as transmitter, the point of attachment of the rod is at
the centre of the diaphragm E, as in Fig. 1.
In this case, the sound waves, in acting on the largo surface of the diaphragm_E,
transmit an increased mechanical action to the iron diaphragin D, and it therefore
follows that the amplitude of the vibrations of this diaphragm becomes greater, and
that consequently through-currents are induced in the bobbins B B¹.
Moreover, the vibrations of the diaphragm D conform perfectly to the sound waves,
and the induced current will cause the perfect reproduction of the words without
distortion.
By increasing the power of the magnets and the diameter of the diaphragm 1, it
will be possible to soud onto the line, currents as strong as may be desired, without
the necessity for correspondingly raising the voice.
When the apparatus is to be used as a receiver capable of reproducing the words
in a loud tono, it is necessary to connect the diaphragmn E to the centre of the
diaphragm D by means of two or more rods F, F, Fig. 2, that is to say, the
attachment is not at the centre of the diaphragm E, but at points a and b, the distance
of which from the centro o depends on the difference of the diameters of tho
diaphragms and E.
It is evident that the amplitude of the vibrations of the diaphragm D will be equal,
in this case, to the amplitudes of the movements of the points ab of the diaphragm E,
and the amplitude of the vibrations of the centre of this diaphragm will be increased
in proportion to the distance of the points a b and of the diameter of the
diaphragm E.
In order to avoid the periodical influence of self-induction, I employ, for the
bobbins B B', a double wire, the one being in communication with the line, as usual,
the other formning a closed circuit on itself, and compensating for the extra currents.
Having now particularly described and ascertained the nature of my said invon-
tion and in what manner the same is to be performed, 1 declare that what I
claim is :
The improvements in magnetic telephony above described, and characterised by
the employment of two diaphragms, one of which is of iron, and arranged between

page_text: the bobbins of two horse shoe magnets, the other of non-magnetic material, and of
a diameter greater than the first, and connected to the centre of the iron diaphragm
by one or more rods made of non-magnetic material, the point of attachment of
these rods being at the centre of the non-magnetic diaphragm when the apparatus
is to serve as a transmitter, but at a distance from the centre when the apparatus
is used as a receiver, the bobbins of the magnets being in all cases connected together
in such a manner that the current resulting is equal to the sum of the currents
induced in each pair.
"
T
T
1.
1040
NEWTON & SON,
Agents for the Applicant.