IMPROVEMENTS IN TELEPHONIC APPARATUS
Year: 1882

page_text: PROVISIONAL SPECIFICATION left by James Grieve Lorrain at the Office
of the Commissioners of Patents on the 30th October 1882.
JAMES GRIEVE LORRAIN, Civil Engineer, of 2 Victoria Mansions in the City of
Westminster. IMPROVEMENTS IN TELEPHONIC APPARATUS
My invention relates to improvements in Electric Telephonic Apparatus
whereby a vibrating plate of magnetic material or substance capable of inductive:
action as usually employed may be dispensed with whilst at the same time.
instruments of great simplicity and efficiency are obtained
In carrying the said invention into practice I pass a current of electricity
through two or more moveable and adjacent parts of a continuous conductor and
by causing the parts of the said conductor to approach or recede from each other,
as for example when connected with a diaphragm or other similar device capable of
vibrating freely, an undulation or variation in the strength of the current is
produced due to the action of the current upon itself, and if the undulatory current
thus produced be sent through two or more moveable and adjacent parts of
another conductor the said current will cause an attractive or repulsive action to
take place between the said moveable and adjacent parts of the conductor which
action may be used to set in vibration a diaphragin or similar device placed in
mechanical connection therewith. It will be obvious that there are many ways of
carrying these principles of action into practice some of which are hereinafter
described.
The instruments constructed according to my invention may be used as
transmitters, as receivers, or as both.
In one form of instrument I employ a spiral of wire the convolutions of which
are to be arranged close together but not in contact with each other. One end of
the said spiral is attached in any convenient manner and by any suitable
mechanical arrangement to the framework of the instrument and preferably in
such manner as to be capable of adjustment from the exterior of the instrument,
as for instance, by means of a screwed stud or bolt or in any other well known
manner. The said end of the spiral is electrically connected with a terminal on
ID 37

page_text: the exterior of the instrument. The other end of the said spiral may be connected
in any convenient manner and by any suitable device to the centre of a thin disc,
diaphragm or plate of brass or other suitable conducting material so mounted as
to be capable of vibrating freely. This disc, diaphragm or plate is electrically
connected with another terminal on the exterior of the instrument. Or instead of
the electric circuit being completed through the disc, diaphragm or plate, the two
ends of the spiral may be electrically connected with the two exterior terminala so
that the circuit is not completed through the disc, diaphragm, or plate and thus
permitting the use of a disc, diaphragm or plate. of any suitable non-conducting
material In this case the said disc diaphragm or plate may be mechanically
connected to the spiral in any convenient manner but preferably in the manner
hereinafter described so as to receive its vibrations therefrom or give its vibrations
thereto according as to whether the instrument is to be used as a telephonic
receiver or transmitter. Instead of using a spiral of ordinary wire I may employ
a flat metallic band which may be of steel coated with copper coiled spirally and
of any desired pitch and electrically connected at its ends with the terminals of
the instrument in either of the ways above described. The plane of the broader
surfaces of the band may be either parallel to or at right angles or nearly so to
the axis of the spiral into which it is coiled.
In another form of instrument instead of employing a spiral formed of wire or
of a band as above described. I may employ a series of two or more metallic discs
or annuli placed at a short distance from one another and so connected and
arranged mechanically and electrically as to be free to move or vibrate when
traversed by a current of electricity. The first and last discs or annuli of the series
are electrically connected with the terminals of the instrument either through the
vibrating disc, diaphragm or plate or in the other manner above described. It
will be readily understood that in the last mentioned arrangement the last of the
said metallic discs or annuli might act instead of a separate disc, diaphragm
or plate.
In a further form of the said invention instead of employing the simple spirals
formed of metallic wires or bands as above described or using a series of metallic
discs or annuli I may coil a conducting wire in the form of a series of planes con-
stituting what might be considered as practically discs or annuli. The conductor
so coiled may be arranged in any convenient manner and electrically connected to
the terminals as above described. In this case also it will be understood that the
upper coil or plane might take the place of a separate disc, diaphragm, or plate
I may make a connection between the vibrating disc, diaphragm or plate and
the spiral or series of discs or plates or planes by means of a wire either straight
or otherwise or by means of a small pin or rod of conducting or nonconducting
material according as the vibrating disc diaphragm or plate is or is not employed
for completing the electric circuit. The ends of the wire pin or rod may be secured
to the vibrating disc diaphragm or plate and to the spiral or series of discs or
planes or coils by means of solder or screw and nut connections or otherwise but I
do not wish to confine myself to any particular method of attachment
Instead of employing one spiral or one series of discs or annuli or one series of
flat planes or coils of wire I may employ two or more of any of these forms of
conductors and arrange them side by side in the same instrument in each case
attaching each spiral or series of discs or planes or coils to a bar disc or plate and
mechanically connecting this with the vibrating disc diaphragm or plate so that
the latter shall receive its vibrations from the whole of the said discs, annuli, plancs
or coils; or the vibrating disc, diaphragm or plate may be fixed at its centre and
the various forms of conductors above described placed side by side and attached
directly to the periphery of the said disc, diaphragm, or plate; or these various
contrivances might be combined and attached to two or more vibrating discs,
diaphragms or plates and placed in one case or box.
To increase the action of the current in the conductor in the forms above

page_text: described I may insert an iron core or envelope it wholly or partly in an iron
sheath or place it in a magnetic field.
I may employ for the conductors above described wire of round, elliptic,
rectangular or other suitable section."
The parts above described may be arranged in a box or case of any suitable form,
provided with a mouth piece or ear piece.