MENTS IN ELECTRIC TELEPHONY
Year: 1885

page_text: I JAMES GRIEVE LORRAIN of 37 Brooke Street, Holborn in the City of London
Consulting Engineer do hereby declare the nature of my Invention for IMPROVE-
MENTS IN ELECTRIC TELEPHONY to be as follows:-
My invention relates to improvements in Electric Telephony, whereby an apparatus
of great simplicity is obtained.
In carrying my invention into effect I employ an apparatus consisting of or com-
prising in its simplest form a disc plate or other shaped mass of conducting material
capable of movement as a whole, or of movement, bending or vibration in part-
like a diaphragm for example. From the centre or any convenient part of the said
dise plate or other shaped mass, hereinafter called the plate, a point, also of con-
ducting material, projects. Opposite this point, and in close proximity thereto, is
placed a suitable conductor, of any desired shape, which is hereinafter called the
knob. Either the plate or the knob may be in electrical connection with the line
or with earth.
r
This apparatus may act both as transmitter and as receiver.
To explain the action of my apparatus let us take the case where the knob of
the transmitter and the plate of the receiver are connected to line. When an
electric charge or current of high potential is transmitted to the plate (with the
point projecting therefrom) of the receiver, the well known phenomenon of point
discharge takes place. The reactive effect of the electricity escaping from the point
will cause the plate to move or bend in the opposite direction to that in which the
electricity is escaping. The greater the charge of electricity the greater the amount
of movement or bending; the less the charge of electricity the less the movement
or bending. The vibrations of the plate of the receiving apparatus will therefore
correspond with the electrical pulsations sent along the line from the transmitter.
The sound waves impinging on the point bearing plate, charged electrically by any
convenient method, of the transmitter, cause it to vibrate towards and away from
the knob. The nearer the point approaches the knob the more electricity will
escape from the point to the knob and so along the line to the receiver; the further
it recedes from the knob the less electricity will pass. The electrical pulsations sent
along the line will therefore correspond with the sound waves actuating the
transmitter. It has been shown that the vibrations of the receiving plate are
uniform with the electrical pulsations sent along the line, therefore they, and the
[Union G31

page_text: sound waves produced by them at the receiving end, will be uniform with the
sound waves actuating the transmitter.
As an alternative arrangement the point, whether in the case of the transmitter
or the receiver, may be either on the vibrating or plate portion of the apparatus,
or on the fixed or knob portion of the apparatus. Thus the point may act either
as a point discharger or as a point collector, as will be readily understood.
The plate may be of non-conducting material if desired, in which case the point
may be connected with the conducting circuit or with the charging source by
conducting wire or foil or their equivalent.
Duplex arrangements may be employed in which two points projecting towards
each other are used, the one acting as a point discharger & the other as a point
collector.
If desired the knob may be dispensed with in the case of the receiver.
It is not necessary that the point should be strictly speaking a point; any pro-
tuberance or projecting part will answer the purpose. Nor is it necessary that the
knob should be an actual knob as generally understood by that term; any conductor
even of the form of a flat plate will do.

page_text: I, JAMES GRIEVE LORRAIN, of 3 Vernon Chambers, Southampton Row, in the
County of Middlesex, formerly of 37 Brooke Street, Holborn, in the City of
London, Consulting Engineer, do hereby declare the nature of my invention for
IMPROVEMENTS IN ELECTRIC 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 improvements in Electric Telephony whereby an apparatus
of great simplicity is obtained.
In carrying my invention into effect I employ an apparatus consisting of or com-
prising in its simplest form a disc, plate or other shaped mass of conducting material.
capable of movement as a whole or of movement bending or vibration in part, like
a diaphragm for example. From the centre or any convenient part of the said disc
plate or other shaped mass, hereinafter called the plate, a point also of conducting
material projects. Opposite this point and in proximity thereto may be placed a
suitable conductor of any desired shape, which is herein after called the knob.
Either the plate or the knob may be in electrical connection with the line or with
earth.
This apparatus may act both as transmitter and as receiver.
To explain the action of my apparatus, let us take the case where the knob of
the transmitter and the plate of the receiver are connected to line. When an
electric charge or current of high potential is transmitted to the plate (with the
point projecting therefrom) of the receiver, the well known phenomenon of point
discharge takes place. The reactive effect of the electricity escaping from the point
will cause the plate to move or bend in the opposite direction to that in which
the electricity is escaping. The greater the charge of electricity the greater the
amount of movement or bending; the less the charge of electricity the less the
movement or bending. The vibrations of the plate of the receiving apparatus will
therefore correspond with the electrical pulsations sent along the line from the
transmitter.
The sound waves impinging on the point bearing plate, charged electrically by
any convenient method, of the transmitter, cause it to vibrate towards and away
from the knob. The nearer the point approaches the knob the more electricity will
escape from the point to the knob, and so along the line to the receiver; the further
it recedes from the knob the less electricity will pass. The electrical pulsations
sent along the line will therefore correspond with the sound waves actuating the
transmitter.
:
It has been shown that the vibrations of the receiving plate are uniform with
the electrical pulsations sent along the line, therefore they, and the sound waves
produced by then at the receiving end, will be uniform with the sound waves
actuating the transmitter.
As an alternative arrangement the point whether in the case of the transmitter
or the receiver may be either in the vibrating or plate portion of the apparatus or
on the fixed or knob portion of the apparatus,

page_text: Thus the point may act either as a point discharger or as a point collector as will
be readily understood.
The plate may be of non-conducting material if desired, in which case the point
may be connected with the conducting circuit or with the charging source by
conducting wire or foil or their equivalent...
Duplex arrangements may be employed in which two points projecting towards
each other are used, the one acting as a point discharger and the other as a point
collector.
If desired the knob may be dispensed with in the case of the receiver.
It is not necessary that the point shall be strictly speaking a point; any pro-
tuberance or projecting part will answer the purpose.
Nor is it necessary that the knob should be an actual knob as generally understood
by that term; any conductor even of the form of a flat plate will do.
When the currents employed to actuate the instruments are of very high
potential it is not necessary that any parts of the instruments be of highly con-
ducting material.
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. As a telephone transmitter the point discharge instrument substantially as
described.
2. As a telephone receiver the point discharge instrument substantially as
described.