Year: 1886

page_text: Date of Application, 29th Apr., 1886.
Complete Left, 31st Jan., 1887.
Complete Accepted, 1st Mar., 1887.
I, JOHN LORIMER CORBETT of 69 Union Street, in the City of Glasgow, Watch-
maker, do hereby declare the nature of this invention to be as follows:-
The object of my invention is to make provision for transmitting telephonic impulses
or messages over distances greater than those over which speech can be transmitted by
the use of the ordinary telephonic apparatus, while obviating the employment of the
double lines of wire or loop circuits of the apparatus heretofore designed for a like
purpose. For such long-distance speaking I employ telephone lines which are divided
into sections of such length as may be conveniently spoken over by the use of the
ordinary instruments and I connect the several sections through relay apparatus which
automatically throws into circuit an auxilliary battery or batteries provided in
connection with each section to supplement or reinforce the currents therein, and I
employ such relay apparatus either alone or in conjunction with apparatus hereinafter
described whereby the impulses transmitted along each section of the line are
The relay
translated or conveyed to the succeeding section in either direction.
apparatus may consist of an electro magnet whose coils are in the line circuit on in a
shunt thereto and having in proximity to its core or cores an armature which when
attracted by the electro magnet serves to close a circuit (which is normally open) and
connect the auxilliary battery to the line, one electrode of the battery being connected
to earth and the other to a terminal with which the relay armature, which is connected
to the line, makes contact. By this arrangement when the subscriber or operator
removes his telephone from the hook or spring support and the usual local battery is
thereby brought into the circuit the cores of the relay magnet will be magnetised the
relay armature will be attracted and the auxilliary battery brought into the line circuit ;
and when the telephone is replaced, the local battery being thereby cut off, the relay
armature will be released and the auxilliary battery thrown out of circuit. The
apparatus for translating the telephonic impulses from one section to another over the
line, and which I employ in conjunction with the relay arrangement above described,
may consist of a telephone receiver combined in a well known manner with a trans-
mitter of ordinary forin at each "station" or junction of the sections into which the

page_text: line is divided and connected as follows:-One section of the line wire passing through
the coils of the relay magnet, or to which such coils are a shunt, is connected to the
electro magnet coils of a "receiver" and thence to earth, and one terminal or branch
wire of the transmitter which is acted on by the vibrating plate or diaphragm combined
with such receiver is connected to the next section of the line, the other terminal or
branch being connected to earth but having interposed a suitable resistance. This
arrangement so far provides for translating telephonic impulses in one direction only,
but to provide for speaking in both directions and at the same time charging the line
from the auxilliary batteries, duplicate translating and relay devices are introduced and
are connected in like manner to the second section of the wire. Thus the. terminal of
each section of the line at each "station" is electrically connected to a relay magnet,
to the coils of one "receiver and to the mechanism of the transmitter combined with
the second receiver. A single transmitter connected to both sections of the line at
each station may suffice provided the vibrating diaphragm or plate be placed between
the cores of the electro magnets of both receivers so that the vibrations of the
diaphragm produced by the electrical impulses passing through the coils of either of
said magnets may be communicated to the transmitter mechanism in contact with the
diaphragm.
In constructing the translating devices I prefer to employ in lieu of the ordinary
forms of receiver and transmitter, a receiver consisting of a horse shoe magnet or soft
iron core each limb of which is surrounded by a coil in circuit and having in lieu of
the ordinary diaphragm or disc a thin metallic plate extending across both cores or
ends of the horse shoe and suspended like a pendulum from a pivot pin or spindle, and
a transmitter consisting of a small ball or block of carbon, or other material commonly
employed as a contact piece in telephone transmitters, suspended from or balanced
upon a pivot pin and bearing against a platinum point on the receiver plate the pressure
against such contact point being merely that due to the tendency of the carbon block
to seek its position of stable equilibrium; or I may from the translating devices by
combining together in the manner above described any of the forms of receivers and
transmitters described in the Specifications filed with my applications for Patents of
even date herewith.
To provide for calling subscribers by means of magneto or other call bells which
cannot be acted on through the translating devices connecting the sections of the line,
I attach to a spring arm in front of the cores of the relay magnets at each "station
on the line, an armature which is at such a distance from the cores as to be unacted on
by the usual local battery currents but which is attracted or alternately attracted and
released upon the passage through the coils of the relay magnet of the ringing current,
according as said current is continuous or alternating; and the movement of said
armature brings a metallic arm thercon into a position in which by bearing on or
vibrating between two terminals of branch wires connecting the sections of tlie line
it short-circuits the translating devices during the ringing operation.
CRUIKSHANK & FAIRWEATHER,
Glasgow, Agents.

page_text: I, JOHN LORIMER CORBETT, of 69 Union Street, in the City of Glasgow, Watch-
maker, 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 my invention is to make provision for transmitting telephonic impulses
or messages over distances greater than those over which speed can be transmitted by
the use of the ordinary telephonic apparatus, while obviating the employment of the
double lines of wire or loop circuits of the apparatus heretofore designed for a like
purpose. For such long distance speaking I employ telephone wires which are divided
into sections of such length as may be conveniently spoken over by the use of the
ordinary instruments and I connect the several sections through relay apparatus which
automatically throws into circuit an auxilliary battery or batteries provided in connection
with each section to charge such section or reinforce the current therein, and I employ
such relay apparatus either alone or in conjunction with apparatus hereinafter described
whereby the impulses transmitted along each section of the line are translated repeated
or conveyed to the succeeding section in either direction.
In the accompanying drawings the combined relay and translating or repeating
apparatus referred to is shown in side elevation at figure 1, in plan at figure 2, in end
elevation at figure 3, and in detail at figures 4 and 5, the relay and translating devices
being in duplicate and so arranged as to permit of the transmission of speech in both
directions over a single line composed of sections as above mentioned; whilst figures 6
and 7, represent in side and end elevations a form of relay apparatus to be employed
alone for reinforcing the current in the sections of the line.
The apparatus as shown in figures 1 to 5 forms a complete instrument one part of
which is used to connect each section to the next section in succession throughout the
line and it comprises a combined telephone receiver and transmitter in duplicate con-
sisting the one of the electro magnet A, and diaphragm B, forming a receiver and a
contact point on the diaphragm in conjunction with a carbon block C, forming a
transmitter and the other of the like parts A, B, C; and an electro magnet D, D, and
relay battery circuit to cach combined receiver and transmitter, the devices being
carried upon a suitable board N, of dry wood or other electrical nonconductor. The
relay apparatus employed consists of an electro magnet D, whose coils are in the line
circuit or in a shunt thereto, the line wire entering at the terminal L, being connected
to the bracket M, and through the contact spring m to the armature d of the electro
magnet D, whence the line passes through the coils of the electro magnet D, and

page_text: through the receiver electro magnet A, and thence to earth by way of the terminal E.
The armature d when attracted by the electro magnet D serves to close a circuit
(which is normally open) and connect an auxilliary battery G to the line, one electrode
of the battery being connected to earth and the other to a terminal F, with which the
relay armature d, which is connected to or forms part of the line, makes contact when
said armature on being attracted towards the cores of the electro magnet D, acting
through a pine at its end presses a spring in contact with a conductor f¹ on the
terminal F. By this arrangement when the subscriber or operator removes his
telephone from the hook or spring support and the usual local battery is thereby
brought into the circuit the cores of the relay magnet D will be magnetised, the relay
armature will be attracted and the auxilliary battery G, brought into the line circuit,
the auxilliary battery current being transmitted through the conductor f", the spring,
and the conducting wire to the diaphragm B, thence through the contact points b, C,
of the transmitter to the conductor J, to which the next section of the line is connected,
said current then forming the sole means of magnetising the coils of the receiver
electro-magnet at the next station, or if the sections of the line are separately charged
serving to reinforce the permanent current in such sections.
22
The pine is provided with an insulating piece el where it makes contact with
the spring, so that the auxilliary battery current may not pass through said pin to the
armature d, and to earth but must find its earth after passing through the coils of the
receiver electro magnet (A) at the next station. When the telephone is replaced after
use the usual local battery being thereby cut off the relay armature d will be released
and the auxilliary battery thrown out of circuit. The apparatus for translating the
telephonic impulses from one section to another over the line, and which I employ in
conjunction with the relay arrangement above described consists as above mentioned
of a telephone receiver A, combined in a well known manner with a transmitter C, of
ordinary form at each "station or junction of the sections into which the line is
divided a single diaphragm B, serving in the present instance both for receiver and
transmitter, and the connections being as follows, One section of the line wire entering
at the terminal L; and passing through the coils of the relay magnet D, (or to which
such coils may be a shunt) is connected to the electro magnet coils A, of the
"receiver B, and thence to earth at E, and the one terminal J', of the transmitter
carbon C (which is pivotted on a metallic strip e fastened to but insulated from a
bracket I, carrying the diaphragm B, and is acted on by the vibrating plate or
diaphragm B) is connected to the next section of the line, the other terminal being
formed by a metallic strip I, bearing on the diaphragm and connected to the auxilliary
battery by the wire . This arrangement so far provides for translating telephonic
impulses in one direction only, but to provide for speaking in both directions and at
the same time charging the line from the auxilliary batteries the translating and relay
devices with their connections are employed in duplicate, the second set of devices
connecting in like manner the sections of the line and being indicated by corresponding
reference letters. Thus the terminal of each section of the line at each "station" is
electrically connected through a relay magnet, to the coils of one receiver and to
the mechanism of the transmitter combined with the receiver at the next station:
coil or other resistance R, having electrical resistance greater than the combined
resistance of the electro magnets in either set of the devices described is interposed
between the line wire and the terminal J₁, connected to the conductor J, of cach
transmitter so that currents transmitted through the line to the instrument may not
find a short circuit directly to the transmitter but will pass by the terminal L, to the
electro magnets D and A, and thence to earth and will thus act on the diaphragm B ;
and a resistance coil R', of less resisting value than the coil R, but of greater value
than the resistance of the section of the line to which it is connected is interposed
between each section of the line and the terminal L, in order to prevent the passage of
the outflowing current from the conductor J, and terminal J¹, by way of the terminal L,
instead of to the line.
$:
A
A single transmitter C, connected to both sections of the line at each station may

page_text: suffice provide the single vibrating diaphragm or plate of such transmitter be placed
between the cores of the electro magnets of both receivers so that the vibrations of
the diaphragm produced by the electrical impulses passing through the coils of either of
said magnets may be communicated to the transmitter mechanism in contact with the
diaphragm, or any forms of telephone receivers and transmitters other than those
described may be combined in the manner above mentioned for the purpose herein
set forth.
To provide for calling subscribers by means of magneto or other call bells which
cannot be acted on through the translating devices connecting the sections of the line
without injuring such devices, a spring attached to the board N, and connected by
the wire o to the line terminal L, is so fitted over but normally out of contact with a
conducting piece m' on the bracket M, that upon the depression of the spring an
insulated arm on it presses the spring o into contact with the piece m¹; and the
magneto current entering from the line at 1, passes alternately by way of the bracket M,
spring m, armature d and coils D and A, to earth at E, and (on the depression of
the armature d and the springs and o) by way of the bracket M, piece m², spring o
and wire o' to the terminal I, of the next section of the line finding earth at the
instrument at the end of the line. When the armature d is fully depressed and
vibrates by the action of a strong magneto current the spring m is out of contact with
it though said spring remains in contact when the armature is depressed by the action
of the battery current. In practice the magneto current produces a vibration of the
armature & whereby contact is alternately made between the spring o and piece m³ and
the spring m and armature d, the current finding earth alternately at E, and at the
distant station, and the ringing action being intermittent at the distant station. The
same object may be attained by fitting a separate pin on the armatured to bear directly
on and by depressing the spring o to close the circuit through M, m', o, o', to connect
the sections of the line, the armature d, being operated by a magneto or strong battery
current from the sending station. Or I may employ the arrangement shown at
figures 6 and 7 in which I attach to a spring arm d¹ in front of the cores of the relay
magnet D', at each "station" on the line an armature which is at such a distance
from the cores as to be unacted on by the usual local battery current but which is
attracted or alternately attracted and released upon the passage through the coils of
the relay magnet D₁, of the ringing current according as said current is continuous or
alternating, and the movement of said amature D¹, through the spring arm d' thereon
brings a terminal spring n, of the line 1, to bear on or vibrate between two terminals p, 1,
of branch wires p, q, the one directly and the other by way of the electro magnet
coils, connecting the sections of the line, and thus during the ringing operation short
circuit the translating devices (which are not shown in these figures). In front of the
cores of the electro magnets D, a thin metallic plate P, extending across both cores is
suspended like a pendulum from a supporting bracket 1". This plate P, is attracted
towards the electro magnet cores, when they are magnetised by the passage through
them of the current from the telephone local battery on lifting the telephone from the
hook, and makes contact with pins or studs & forming terminals of an auxilliary
battery circuit whereby the auxilliary battery circuit is closed through the plate P, and
bracket P, to the succeeding section of the line land the current therein is reinforced.
The electro-magnet D', and devices connected with it as also the auxilliary battery G,
are in duplicate as shown, when a single wire is employed for sending messages in
either direction, and a relay apparatus of the kind described may be connected at
intervals in the length of a line to introduce fresh battery charges into the several
sections of which it is composed upon the transmission of a message through the line,
the use of translating devices being dispensed with.
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. The combination of parts constituting the telephonic relay and translating
instrument, herein described with reference to figures 1 to 3 of the annexed drawings.

page_text: 2. In a telephone line composed of two or more sections, the employment in
conjunction with a combined telephonic receiver and transmitter of relay apparatus,
substantially as and for the purpose set forth.
3. In a telephone line composed of two or more sections the employment of relay
apparatus, substantially as and for the purpose described.
4. In an instrument for translating or conveying telephonic messages from one
section to another of a telephone line the provision of devices for short circuiting the
translating apparatus and permitting the direct transmission of ringing currents
substantially as described.
CRUIKSHANK & FAIRWEATHER,
62, Saint Vincent Street, Glasgow,
Agents.