IMPROVEMENTS IN TELEPHONIC AND MICROPHONIC TRANSMITTING INSTRUMENTS
Year: 1882

page_text: LETTERS PATENT to John Imray of No 28 Southampton Buildings Chancery
Lane in the County of Middlesex for an Invention of IMPROVEMENTS IN
TELEPHONIC AND MICROPHONIC TRANSMITTING INSTRUMENTS Communi-
cated to me from abroad by Dr. Julian Ochorowicz of Paris France
PROVISIONAL SPECIFICATION left by the said John Imray at the Office of
the Commissioners of Patents on the 30th December 1882.
JOHN IMRAY of No 28 Southampton Buildings, Chancery Lane, in the County
of Middlesex "IMPROVEMENTS IN TELEPHONIC AND MICROPHONIC TRANSMITTING.
INSTRUMENTS [A communication to me from abroad by Dr. Juliau Ochorowicz
of Paris France.]
39
This invention relates to a method of applying in the construction of telephonic
or microphonic transmitting instruments, certain well known magnetic phenomena
which are as follows. When filings of iron or other magnetic metal are placed
between the poles of magnets they arrange themselves in peculiar forms, and any
vibratory or other movement of either magnet causes a movement of these particles.
By employing such particles placed in a magnetic field to form part of an electric
circuit, the vibration of one of the magnets resulting from pulses of sound causes
movements of the particles, and these movements produce electrical undulations in
the circuit, so that the sound pulses can be reproduced by a suitable receiving
instrument at a distance. Transmitting instruments based on this principle may
be made in many different forms. For example, a strong plate or disc of iron or
steel may be fixed a little above a pair of magnets presenting opposite poles
towards each other with magnetic filings between them; the circuit wires being
attached to the magnets, the vibrations of the plate or disc will cause the required
electrical undulations in the circuit. Or a strong disc or plate may have a small
magnet attached to its under side immediately above a thin disc of brass or other
non-magnetic but conducting material below which is the pole of a magnet or
electromagnet with the magnetic filings. The magnet and the disc being put in
circuit the vibrations of the plate carrying the small magnet cause the required
electrical undulations in the circuit. A convenient form of instrument is the
following. Centrally within a block of ebonite or such like insulating material is
fixed a bar magnet and on one end of the block is fixed a strong disc of steel, the
centre of the disc being at a little distance from the pole of the magnet, and this
space being occupied by magnetic filings. The circuit wires are attached, the one
to the magnet and the other to the steel disc, so that the magnetic filings form
part of it.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said John Imray in the Great Seal Patent Office on the 29th June
1883.
JOHN IMRAY of N° 28 Southampton Buildings, Chancery Lane, in the County
of Middlesex "IMPROVEMENTS IN TELEPHONIC AND MICROPHONIC TRANSMITTING
INSTRUMENTS A communication to me from abroad by Dr Julian Ochorowicz of
Paris, France
"
This invention relates to a method of applying in the construction of telephonic
or microphonic transmitting instruments, certain well known magnetic phenomena
which are as follows:-When filings of iron or other magnetic metal are placed
between the poles of magnets they arrange themselves in peculiar forms, and any
vibratory or other movement of either magnet causes a movement of those particles.
By employing such particles placed in a magnetic field to form part of an electric
circuit, the vibration of one of the magnets resulting from pulses of sound causes
movements of the particles, and these movements produce electrical undulations in
the circuit, so that the sound pulses can be reproduced by a suitable receiving
instrument at a distance. Transmitting instruments based on this principle may
be made in many different forms. For example, a strong plate or disc of iron or
steel may be fixed a little above a pair of magnets presenting opposite poles
towards each other with magnetic filings between them, the circuit wires being
attached to the magnets, the vibrations of the plate or disc will cause the required
electrical undulations in the circuit. Or a strong disc or plate may have a small
magnet attached to its under side immediately above a thin disc of brass or other
non-magnetic but conducting material, below which is the pole of a magnet or
electro-magnet with the magnetic filings. The magnet and the disc being put in
circuit the vibrations of the plates carrying the small magnet cause the required
electrical undulations in the circuit. A convenient form of instrument is the
following. Centrally within a block of ebonite or such like insulating material is
fixed a bar magnet, and on one end of the block is fixed a strong disc of steel, the
centre of the disc being at a little distance from the pole of the magnet, and this
space being occupied by magnetic filings. The circuit wires are attached, the one
to the magnet and the other to the steel disc, so that the magnetic filings form
part of it.
Fig 1 of the accompanying drawings illustrates the condition of magnetic filings
between two opposite magnetic poles N and S. If they are between like poles
they are repelled as indicated by Fig 2. If as shewn in Fig 3 a plate A of iron or
steel be vibrated in the neighbourhood of the polar field B B in which the magnetic
powder forms a conductor between two magnets forming part of the electric
circuit, there will be electrical undulations in that circuit. Or again, as
shewn in Fig 4, if there be a single magnet N S and a tympan or diaphragm A B
carrying a piece of iron C presented towards a pole of NS; when the diaphragm
vibrates there will be electrical undulations in the circuit of which the magnet and
the metallic frame that carries the tympan form parts, the magnetic powder being
interposed between them. Fig 5 shews an instrument in which the same principle
is applied in a form convenient for use. The magnet NS is fixed adjustably in a
block of insulating material, such as ebonite and its projecting end N is covered by
a short piece of tube of the same material or of caoutchouc. The tympan NSN is
in this case a permanently magnetic disc.
Obviously the instrument might be made in many other forms, the magnets
being arranged in such a manner as to act on magnetic powder forming part of the
electrical circuit.

page_text: Having thus described the nature of the said invention, and in what manner the
same is to be performed, as communicated to me by my foreign correspondent, I
claim:-
In a telephonic or microphonic transmitting instrument, forming part of the line
circuit by magnetic powder in a magnetic field, so that as the field is varied by
vibrations caused by sound pulses, the resulting changes in the condition of the
powder particles cause electrical undulations in the circuit, substantially as and for
the purposes herein set forth.
In Witness whereof, I the said John Imray have bercunto set my hand and
seal this Twenty-ninth day of June in the year of our Lord One thousand
eight hundred and eighty-three
JOHN IMRAY (L.S.)