IMPROVEMENTS IN TELEPHONIC SIGNALLING AND COMMUTATING APPARATUS
Year: 1881

page_text: LETTERS PATENT to John Imray, of No. 28, Southampton Buildings, in the
County of Middlesex, for an Invention of "IMPROVEMENTS IN TELEPHONIC
SIGNALLING AND COMMUTATING APPARATUS.”
by Clement Ader, of Paris, France.
A communication from abroad
PROVISIONAL SPECIFICATION left by the said John Imray at the Office
of the Commissioners of Patents on the 7th July 1881.
JOHN IMRAY, of No. 28, Southampton Buildings, in the County of Middlesex.
"IMPROVEMENTS IN TELEPHONIC SIGNALLING AND COMMUTATING APPARATUS."
[A communication from abroad by Clement Ader, of Paris, France.]
In a system of telephonic communication there are generally besides the central
office several auxiliary offices with which the subscribers of particular districts are
connected, these auxiliary offices being all in connection with the central office.
By means of telegraphic signals the official is informed that a subscriber connected
with one office desires to communicate with another subscriber who may be
connected with another office, and then by means of a commutator the official puts
the two subscribers in communication by connecting the wires leading to their
respective instruments. This Invention relates to the signals and commutators
employed for this purpose. For signalling according to this Invention a solenoid
coil without a core is suspended like a pendulum between the poles of permanent
magnets, its middle position being determined by an adjustable counterbalance
weight. The pendulum rod has on it contact studs, which when the pendulum is
in the middle position, are clear from fixed studs communicating by wires with the
signal. On sending an electrical current from a local battery through the solenoid
coil it is caused to move in the one direction or the other, according as the current
is of the one or the other sign. By this deflection of the pendulum one or other of
the contact studs on its rod makes contact by which a current is transmitted to
the signal, causing it to move so as to indicate the desire of the subscriber for
communication. A number of these magnets with their pendulous solenoids are
arranged together, distinguished by numbers or other marks, so that the official

page_text: knows which of the subscribers have to be put in communication. The solenoid coil,
instead of being suspended between magnetic poles, may be mounted to turn on a
pole or to slide along a magnetic bar. For completing communication between
two subscribers, commutators according to this Invention are of the following
description Three plates of metal are fixed parallel to one another with slabs of
insulating material between them. Each plate is connected by a wire to a
telephonic instrument, and through the middle of the three plates there is a hole,
which is largest where it passes through the first or front plate, smaller through
the middle plate, and smaller still through the third or back plate. The official is
provided with two, three, or more keys, each consisting of a handle of insulating
material, from the end of which projects two insulated split tubes of different
lengths and diameters; these tubes in one of the keys being respectively connected
by insulated wires passing through the handles to tubes in others of the keys.
For making a connection the official inserts one of the keys, the tubes of which fit,
it may be the front and the middle holes of one commutator, and inserts another
of the keys, the tubes of which fit the front and back holes of another commutator,
and he thus electrically connects the plates of the two commutators, and through
them the instruments connected to them. For making other connections the
official inserts the keys in other combinations and orders, and thus he is enabled to
couple together the wires of different subscribers as directed by the signals.
When no key is used the front plate is connected to the second plate by an external
spring from which an ivory stud projects transversely into the first hole.
inserting any key the key tube pushes this stud outwards, and thereby breaks the
contact made by the spring from the first to the second plate. On again removing
the key the spring returns to contact, so that the first and second plates of each
commutator form always a closed circuit unless when a key is used to alter the
electrical connections.
On

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Jolin Imray in the Great Seal Patent Office on the 6th January
1882.
JOHN IMRAY, of No. 28, Southampton Buildings, in the County of Middlesex.
"IMPROVEMENTS IN TELEPHONIC SIGNALLING AND COMMUTATING APPARATUS,"
A communication from abroad by Clement Ader, of Paris, France.
In a system of telephonic communication there are generally besides the central
office several auxiliary offices with which the subscribers of particular districts are
connected, these auxiliary offices being all in connection with the central office.
By means of telegraphic signals the official is informed that a subscriber. connected
with one office desires to communicate with another subscriber who may be
connected with another office, and then by means of a commutator the official puts
the two subscribers in communication by connecting the wires leading to their
respective instruments. This Invention relates to the signals and commutators -
employed for this purpose. For signalling according to this Invention a solenoid
coil without a core is suspended like a pendulum between the poles of permanent
magnets, its middle position being determined by an adjustable counterbalance
weight. The pendulum rod has on it contact studs which, when the pendulum is
in the middle position, are clear from fixed studs communicating by wires with
the signal. On sending an electrical current from a local battery through the
solenoid coil, it is caused to move in the one direction or the other, according as the
current is of the one or the other sign. By this deflection of the pendulum one or
other of the contact studs on its rod makes contact by which a current is trans;
mitted to the signal, causing it to move so as to indicate the desire of the subscriber
for communication. A number of these magnets with their pendulous solenoids are
arranged together, distinguished by numbers or other marks, so that the official
knows which of the subscribers have to be put in communication. The solenoid
coil instead of being suspended between magnetic poles, may be mounted to turn
on a pole or to slide along a magnetic bar. For completing communication between
two subscribers, commutators according to this Invention are of the following
description Three plates of metal are fixed parallel to one another, with slabs of
insulating material between them. Each plate is connected by a wire to a
telephonic instrument, and through the middle of the three plates there is a hole
which is largest where it passes through the first or front plate, smaller through
the middle plate, and smaller still through the third or back plate. The official is
provided with two, three, or more keys, each consisting of a handle of insulating
material, from the end of which projects two insulated split tubes of different
lengths and diameters, these tubes in one of the keys being respectively connected
by insulated wires passing through the handles to tubes in others of the keys. For
making a connection the official inserts one of the keys, the tubes of which fit, it may
be, the front and the middle holes of one commutator, and inserts another of the
keys, the tubes of which fit the front and back holes of another commutator, and
he thus electrically connects the plates of the two commutators and through them
the instruments connected to them. For making other connections the official
inserts the keys in other combinations and orders, and thus he is enabled to couple
together the wires of different subscribers as directed by the signals. When no
key is used, the front plate is connected to the second plate by an external spring,
from which an ivory stud projects transversely into the first hole.
On inserting
any key the key tube pushes this stud outwards, and thereby breaks the contact
made by the spring from the first to the second plate.. On again removing the
-

page_text: TO Wways a ՆՈՆԱ ՆԱՆ-ն,
electrical connections.
DESCRIPTION OF THE DRAWINGS.
Fig. 1 is a front view, Fig. 2 a plan, and Fig. 3 a side view of signalling apparatus
according to this Invention, Fig. 4 being a view of the pendulous coil detached.
A, A, are two permanent magnets fixed in a box. These magnets are bent as
shewn, and have soft iron terininals N and S in the form of elbows arranged so as
to form strong magnetic fields. Between the two magnets is suspended as a
pendulum the coil H, which has no magnetic core, and which is more or less
balanced by the adjustable counterpoise P. The pendulum is free to rock on its
horizontal axis X, the conducting wires F, F¹, to and from the coil being helically
twisted to give flexibility. These wires form part to the telephonic circuit. Instead
of flexible wires contact might be made to the pivots of the axis, or mercurial
contacts might be employed. The diagram, Fig. 5, shews the connections for a
number of subscribers, the pendulous coils in that Figure being numbered 1, 2, 3,
&c., each between its pair of magnets A, A¹, A, etc., which present to the coils
poles of alternating polarity. The local circuit in each case is closed by the
contact T connecting the subscribers' indicator with one of the poles of the local
battery, or by E connecting all the magnets by a line M. (Fig. 5) to the other pole;
thus the local circuit can be closed for each relay by passing through an indicator
and through the local battery, which is common to them all. According as a
positive or negative current, even when it is very feeble, passes through the
pendulous coil H, it is moved towards the one side or the other, making connection
for a subscriber's indicator. Fig. 6 is a diagram shewing the connections, and
Fig. 7 is a section; Fig. 8, a plan looking from below, and Fig. 9 a side view of
the commutator for effecting communication between subscribers by means of keys,
such as are shewn in Fig. 10, several of which may be connected by conductors, as
shewn in Fig. 11. The commutator consists of three metal plates insulated from
each other, and secured against the wall or panel by three bolts B, B1, B¹¹, each
bolt connected to one of the plates but insulated from the others. To these bolts
are attached the conducting lines to B, and through it to the front plate is attached
the first line to B', and through it to the middle plate is attached the line which
includes the relay coils, and to B and through it to the hinder plate the line
leading to D (Fig. 6). Through the plates are holes, the largest through the front
plate, a smaller through the middle plate, and a still smaller through the hinder
plate. A spring R fixed to the front plate bends back at its end, so as to bear
against the middle plate, and an ivory pin I resting on the spring projects into the
front hole. The keys, Fig. 10, present two split sockets C, C¹, insulated from each
other and connected to two conducting cords; the sockets C, C¹, are of such size
that when one of the keys is thrust into the hole of the plates it connects the
hinder plate to the front plate, and when the other key is thrust in it connects the
middle plate to the front plate. When either is inserted it, by depressing the ivory
pin I, pushes back the spring R, and so breaks this connection of the front and
middle plates. When neither key is inserted, the front and middle plates, being
connected by the spring R, a subscriber calling sends a current which by the first
line passes to the front plate, thence to the middle plate, and to the relay which
gives the signal, returning by the second line to the subscribers' battery, as indicated
by the diagram, Fig. 6. When the official at the exchange desires to call a sub-
scriber be inserts into the hole the key which puts the front and the hinder plate
in connection, the wires of which are in his telephonic circuit. The current then
passes from the subscriber's telephone through the front plate, thence through the
exchange telephone back to the hinder plate, thence past the relays to the
subscriber's telephone. The official can then communicate with the subscriber
without bringing the relays uselessly into action. When two subscribers are to be

page_text: put in communication, two similar keys connected by their conducting cords are
inserted one into the hole of the plates for the one subscriber, and the other into
the hole of the plates for the other subscriber, the telephones of the two subscribers
being thus put in connection in circuit with the relay, so that when they end their
communication they can signal to that effect. By employing the two different
keys, the one in one hole and the other in the other hole, only one relay is brought
into circuit. When a number of subscribers exceeding two have to be put into
communication, a corresponding number of connected keys are employed. Thus it
will be seen that by employing a hole presenting three parallel contacts and two
kinds of keys, either the exchange can communicate with a subscriber, excluding
the relays, or two or more subscribers can communicate with each other by a circuit,
including the relays. The arrangement of the coil in relation to the magnets, as
shewn in Figs. 1 to 4-inclusive, the coil being suspended as a pendulum is extremely
sensitive as well as simple. The coil might however be arranged otherwise, as in
Fig. 12, mounted on an axis between the magnetic poles; or, as in Fig. 13, free to
slide along a limb of a magnet; or, as in Fig. 14, on a balanced horizontal lever,
free to reciprocate along the magnet.
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,
First. For telephonic signalling the use of a relay consisting of a coil or solenoid,
without a core, mounted free to move in a magnetic field, so that on the passage
through it of an electric current it makes contacts which close a signalling circuit,
substantially as berein described.
Second. For connecting at a central office or exchange the telephones of the
official or of subscribers, the use of commutators and keys, each commutator
consisting of three plates with holes of different sizes fitting corresponding sockets
of the keys, so as to form electrical connections, substantially as herein described.
°
In witness whereof, I, the said John Imray, have hereunto set my hand
and seal, this Sixth day of January, in the year of our Lord One thousand
eight hundred and eighty-two.
JOHN IMRAY. (L.S.)