IMPROVEMENTS IN ELECTRIC TELEPHONY
Year: 1884

page_text: PROVISIONAL SPECIFICATION.
I, JAMES GRIEVE LORRAIN of The Whitehall Club, Parliament Street, in the
City of Westminster Consulting Engineer do hereby declare the nature of my
invention for IMPROVEMENTS IN ELECTRIC TELEPHONY to be as follows:-
My invention, which relates to Electric Telephony, has for its object the
transmission and reproduction of speech and of musical sounds by means of
electricity; and consists of an instrument capable of acting either as a transmitter,
for producing, under the influence of the voice or of a musical instrument, rapid
variations of potential or of charge in a conductor or system of conductors, or as
a receiver, for producing under the influence of such variations of potential or
charge, mechanical vibrations of the air similar to and uniform with those which
actuate the transmitter.
In carrying my invention into effect, I employ an instrument consisting of a
plate, sheet, or mass of nonconducting or other suitable material, hereinafter called
the nonconducting plate, suspended, or otherwise suitably disposed, so as to be able
to vibrate towards and away from a conductor or mass, plate, or sheet of conducting
material, hereinafter called the conducting plate. The nonconducting plate may
either move bodily towards and away from the conducting plate as a whole, or it
may be attached so as only to vibrate towards and away from it as a diaphragm
or tympan. Instead of the nonconducting plate being so disposed as to vibrato
towards and away from the conducting plate, it may be the conducting plate which
is so disposed as to vibrate, either bodily or as a diaphragm, towards and away from
the nonconducting plate. Or, both the conducting and the nonconducting plates
may be so disposed as to vibrate towards and away from each other.
To explain the action of the apparatus constituting my invention, let us consider
the case where two of the instruments are in electrical connection, by a conductor
joining their respective conducting plates, so that one instrument acts as a trans-
mitter and the other as a receiver, and that it is the nonconducting plate in each
which vibrates, The action is as follows. The nonconducting plate of the
transmitter being electrified or charged by any suitable means, such as rubbing
with fur, wool, silk, &c., the air vibrations produced by the voice may be made to
impinge directly or indirectly upon it, so as to cause it to vibrato towards and
away from the conducting plate. The nearer the charged nonconducting plate
approaches the conducting plate in its vibrations the stronger will be the charge

page_text: induced in the latter: the 'further the charged nonconducting plate recedes from
the conducting plate the weaker will be the charge induced in the conducting plate.
The stronger the charge induced in the conducting plate, and conveyed by the
conductor to the receiver, the more will the nonconducting plate of the receiver be
attracted towards its conducting plate i the weaker the charge conveyed by the
conductor the less will the nonconducting plate of the receiver be attracted towards
its conducting plate. The nonconducting plate of the receiver will therefore
vibrate rythmically with that of the transmitter, and cause mechanical vibrations
of the air similar to and uniform with those actuating the transmitter.
As will be readily understood, a similar action takes place in the case where the
conducting plate vibrates towards and away from the nonconducting plate, and
in that where both the conducting and the nonconducting plates vibrate towards
and away from each other.
I may connect my transmitter and my receiver by a single conductor, using
neither metallic circuit, nor earth return. Or, I may connect my transmitter and
my receiver by any of the plans in ordinary use.
I may interpose a charging battery, or an induction coil, or both, between the
transmitter and the receiver, as will be readily understood.
I may duplicate, or multiply, the parts of the instruments, so as to gain increased
-effect;-and I may make them of any convenient form and size.
I-may-if-I-should desire it, cause the plates-to-make_and_break contact with
each other when vibrating.
I may make the distance between the plates adjustable by means of screws or
other equivalent devices.
—acition of the most of the instruments' so

page_text: COMPLETE SPECIFICATION.
I, JAMES GRIEVE LORRAIN, of The Whitehall Club, Parliament Street, in the
City of Westminster, 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 which relates to Electric Telephony has for its object the
transmission and reproduction of speech and of musical sounds by means of
Electricity, and consists of an instrument capable of acting either as a transmitter
for producing under the influence of the voice or of a musical instrument-rapid
variations of potential or of charge in a conductor or system of conductors, or as
a receiver for producing under the influence of such variations of potential or
charge mechanical vibrations of the air similar to and uniform with those which.
actuate the transmitter.
In carrying my invention into effect I employ an instrument consisting of a
plate sheet or mass of a dielectric or non conducting material, hereinafter called the
non-conducting plate, suspended or otherwise suitably disposed so as to be able to
vibrate towards and away from a conductor or mass plate or sheet of conducting
material, hereinafter called the conducting plate. The non-conducting plate may
either move bodily towards and away from the conducting plate as a whole, or it
may be attached so as only to vibrate towards and away from it as a diaphragin
or tympan. Instead of the non-conducting plate being so disposed as to vibrato
towards and away from the conducting plate it may be the conducting plate which
is so disposed as to vibrate either bodily or as a diaphragm or tympan towards
and away from the non-conducting plate; or both the conducting and the non-
conducting plates may be so disposed as to vibrate towards and away from each
other. A description of the mode of action of one of these cases will suffice for
all. To explain the action of the apparatus constituting my invention, let us
consider the case where two of the instruments are in electrical connection by a
conductor joining the respective conducting plates, so that one acts as a transmitter
and the other as a receiver, and that it is the non-conducting plate in oach which
vibrates. The action is as follows: The non conducting plate of the transmitter
being Electrified or charged by any suitable means, such as rubbing with fur, wool,
silk, or by a dry pile or battery etc., the air vibrations produced by the voice may
be made to impinge directly or indirectly upon it, so as to cause it to vibrate
towards and away from the conducting plate.
The nearer the charged non-conducting plate approaches the conducting plate in
its vibrations the stronger will be the charge induced in the latter. The further
the charged non-conducting plate recedos from the conducting plate the weaker
will be the charge induced in the conducting plate.
The stronger the charge induced in the conducting plate and convoyed by the
conductor to the receiver, the more will the non-conducting plate of the receiver bo
attracted towards its conducting plate. The weaker the charge conveyed by the
conductor the less will the non-conducting plate of the receiver be attracted

page_text: '
towards its conducting plate. The non-conducting plate of the receiver will
therefore vibrate rythmically with that of the transmitter, and cause mechanical
vibrations of the air similar to and uniform with those actuating the transmitter.
As will be readily understood a similar action takes place in the case where the
conducting plate vibrates towards and away from the non-conducting plate, and in
that where both the conducting and the non-conducting plates vibrate towards and.
away from each other. I may chargo either the non-conducting plate, as herein-
before mentioned, or the conducting plato of the transmitter.
I may connect my transmitter and my receiver by a single conductor using
neither metallic circuit nor earth return. Or I may connect my transmitter and
my receiver by any of the plans in ordinary use.
I may interpose a charging battery or an induction coil or both between the
transmitter and the receiver as will be readily understood.
I may duplicate or multiply the parts of the instruments so as to gain increased
effect, and I may make them of any convenient form and size.
I may if I should desire it cause the plates to make and break contact with each
other when vibrating. I may make the distance between the plates adjustable by
means of screws or other equivalent devices. I may vary the size shape and
arrangement of the parts of the instruments so that one instrument may be more
suitable for use as a transmitter, and another more suitable for use as a receiver.
"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. In a telephone a transmitter consisting essentially of a conducting plate and
-a-non-conducting plate substantially as and for the purpose specified.
2. In a telephone a receiver consisting-essentially of a conducting plate and a
non-conducting plato-substantially as and for the purpose specified.