Busy Signal for Telephone Circuits.
Year: 1893

page_text: United States of America),
Date of Application (in United Kingdom), 13th May, 1893
Complete Specification Left, 12th Feb., 1894-Accepted, 24th Mar., 1894
PROVISIONAL SPECIFICATION.
Busy Signal for Telephone Circuits.
We, EDWARD JULIUS HALL, of Morris in the County of Morris and State of
New Jersey, and FRANK ALBERT PICKERNELL of Newark in the County of
Essex and State of New Jersey United States of America do hereby declare the
nature of this invention to be as follows:-
This invention relates to the transmission of signals on telephone circuits, and
has been found especially useful in connection with switchboards on which the same
main circuit is represented at more places than one, and which therefore are
necessarily to be supplied with some form of appliance for indicating at one point
on such a switchboard that a given circuit is busy at another point.
Its main object is to provide convenient and suitable means by the aid of which
the occupied state at one portion of a switchboard of a circuit with which connection
is desired may be automatically indicated to the operator at another portion of said
switchboard who is seeking such a connection and also simultaneously announced
(preferably in spoken words) to the customer or substation attendant who desires
to communicate, but the latter part of said operation alone is also frequently useful
and desirable.
The invention which we point out specifically in its several phases, in the claims
at the end of this Specification comprehends any main telephone circuit which
extends from a terminal station where is located a receiving telephone and its
concomitant apparatus to a suitable central or other opposite terminal station where
it may be interconnected with others, or where alternatively it may readily be
united to a continuation loop or branch circuit containing a transmitter adapted to
made.
act upon the said telephone receiver as soon as the said connection
and to produce or reproduce therein an oral or audible signal having a preconcerted
meaning.
The said transmitter is preferably a transmitting telephone connected directly or
inductively in such continuation circuit, and mounted in intimate association with a
constantly operating phonograph which repeats any predetermined word or phrase
into the transmitter mouthpiece, and such word or phrase being reproduced by the
telephone receiver at the distant terminal station imparts any necessary information
to the listening operator or attendant there.
Instead however of a transmitter and phonograph an electrotome or other
intermittent or vibratory circuit breaker such as an ordinary buzzer may be
employed in which event of course the signal received by the said attendant at the
terminal station in his telephone or upon his bell will be a peculiar buzz, hum, ring
or rattle, constituting an arbitrary signal, having an understood meaning.
The invention also comprises the association with such a circuit, of an inter-
mediate station or switchboard connection through which it passes and whence an

page_text: independent signalling circuit extends to the terminal point of the main circuit, a
visual signal indicator included in said independent circuit at the intermediate
station, and an automatic intermittent circuit breaking transmitting device adapted
to effect changes of current in the said independent circuit to which the indicator
therein will respond. This signal transmitter as well as that of the main circuit is
included in a suitable branch or continuation circuit, and the two continuation
circuits may be, and preferably are, provided with a single terminal spring jack or
plug socket within which the terminals of both are contained; both moreover being
normally open or discontinuous in the said spring jack but adapted to be closed
and to become operative upon the insertion within said spring jack of a suitable
plug connector.
The action of this independent circuit transmitter is to produce a trembling or
fluttering of the signal indicator, and thus to give a signal, which may by previous
understanding have any special meaning.
The said continuation circuits being thus provided with a compound signal
transmitter and with a common terminal spring jack, it is convenient to combine
the terminals of the telephone and signalling circuits in a common plug connector
adapted to be inserted in said jack and thereby to complete both circuits and
operate both signals.
One useful adaptation of this invention is its application as a busy signal to
divided or multiple switchboards. The telephone circuit leading from a substation
may connect with two spring jacks at different portions of the switchboard.
"
Should a station call for a connection with a second station which is found to be
busy, the plug terminal of the circuit of the first station may be placed in such a
continuation circuit spring jack as has been described, and by means of the
associated transmitter and phonograph, or other device the word " busy or any
other prearranged word, phrase or other signal may be transmitted to the calling
station, and reproduced in the apparatus there, thus conveying the necessary
information to the customer in an unmistakeable way.
And in central stations where a calling circuit is to be connected with the desired
circuit through the intermediation of office trunks, the visual signal indicator being
placed at the call initiating end of such trunk, the plug connector forming the
remaining trunk terminal becomes virtually the terminal of the call initiating
circuit. When under these conditions the circuit desired is found to be temporarily
occupied with another connection, and the terminal plug placed in the compound
continuation circuit jack, both continuation circuits will be simultaneously close.l,
and the compound transmitter becoming operative will cause the operation of the
audible signal at the call initiating substation and also the operation of the visual
signal at that end of the office trunk nearest thereto; the operators both at the
substation and at the central station being thereby both notified that the desired
connection cannot at present be had.
In a separate application for Letters Patent filed of even date herewith by
Edward J. Hall for a system of central station inter-communication comprising
divided switchboards, ou one of which incoming calls are received, while connections
with desired lines are made on the other, the same being entitled central office
apparatus and circuits for telephone exchanges, these utilizations of our invention
are described and certain combinations of which it forms an element are claimed.
The drawing which accompanies and forms a part of this Specification is a
diagram illustrating conventionally the several arrangements of circuits and
apparatus which have generally been indicated above.
With the exception of the points marked S, S2, S3, and S4 which symbolize
sub-stations fitted of course with the usual telephones t, and telephonic appliances,
together with their respective main circuits C, C2, C3 and C 4, each having direct
and return wires 6 and 7 the entire drawing indicates the circuits and apparatus of
a central station D.
Circumstances however frequently occur where a given circuit as ( represented
at one part X of the central station requires to be connected by means of an office

page_text: trunk conductor Z with a second circuit C 2 or C3 at another part of the central
station or another portion Y of the switchboard.
Under such conditions the first point of connection (that is to say the switch-
board X where the call was received and where the work of connection was
initiated) is virtually an intermediate station on the circuit extending between the
substation S, and the switchboard Y on which are located the connection devices j
of the circuit wanted.
At the substation S, t is the receiving telephone, and is shown at the ear of a
customer A, who is supposed to have sent in an order for connection of a certain
line, and is now waiting to be told either that the connection is completed; or else
that the line wanted is occupied or busy. The terminal spring jack J of the
substation circuit C is represented as having already received the answering plug
of the link connection N whose two conductors 8 and 9 are thus at one end con-
nected with the two main circuit conductors 6 and 7, while at the other end they
terininate in conducting surfaces q and 92 of the plug P, that being adapted for
insertion in the spring jack k of the trunk conductor Z, but shown apart for
convenience of explanation.
The said jack k has two spring contacts 9 and h which register and make contact
with the plug contact surfaces.
The spring contacts g and are the terminals of the two wires 10 and 11 of
the trunk conductor Z and extend to the Y part of the switchboard or office where
they connect respectively with the contact surfaces w and a of another plug
connecter P2 which forms the movable terminal of the said trunk conductor.
The plug P being thrust into the jack k, the surfaces w and x of the other
plug P2 become at once the terminals of the substation circuit C, and the
plug P2 as a whole becomes the movable terminal of the said circuit; on which
the switch connections at X have also become practically an intermediate station.
If now the plug P 2 be placed in the spring jack ; of circuit C 2, its contact
surfaces w and make contact with the spring contacts e and f of said jack,
establishing through communication between the substations S and $2 over the
two circuits C and C 2, the link connection N and the office trunk conductor Z.
K is an auxiliary spring jack located at Y its form being similar to the
others. Its principal spring contacts m and n are united to the ends of two
conductors 4 and 5 of a loop circuit c2 connecting with a signal transmitting
device. At the other end of such loop circuit I show as alternative signal
transmitters, a telephone transmitter T, and a phonograph G mounted immediately
in front of the mouth piece thereof; and a vibratory circuit breaker or buzzer V
operated by an electromagnet in a local circuit (not shown).
These devices may of course be connected either directly in the circuit c 2, or
they may be, and preferably are connected as shown, in a local circuit c and
arranged to act upon the circuit c2 through and by means of an induction coil I
which has its primary helix in the circuit c and its secondary helix in the
circuit c 2.
To operate the buzzer V, the switch s is placed on the button 3, and the buzzer
then intermits the circuit c of the battery L at the points u, u 2 rapidly, and
thereby sends induced currents into the circuit c 2 in rapid succession, which if
a telephone be included in such circuit, will produce a loud buzz therein.
We prefer however for our present purpose to use the transmitting telephone T.
Any words spoken into this transmitter will of course induce voice currents by
means of the induction coil I in the circuit c 2. If a telephone be connected in
the said circuit, the words which originated such voice currents, will be reproduced
by their action therein, and a copy of the said words will be heard in the
telephone.
The phonograph can readily of course be arranged to speak any words or
phrases desired in the transmitter mouthpiece. We have used a phonograph in
this association as a busy switchboard and station signal which we have equipped
with a cylinder repeating the word "busy" continuously.

page_text: For such work the form of metallic record employed in the process described
in Letters Patent of the United States No. 372,786 granted November 8, 1887 to
Emile Berliner would probably be well adapted.
The plug P2 representing the terminal of the telephone circuit may be
placed in the spring jack K. When so placed, the circuit c 2 may be regarded
as a continuation circuit of the circuit C, which is now extended to the trans-
mitter T and the words uttered by the phonograph are heard in the telephone
at S.
Considering the invention in its application to switch boards the jack K, may
be entitled the "busy jack," and several may be employed. When therefore it
is found that the circuit with which communication is required (say S2) is in
use, the plug is at once placed in the busy jack, and the customer or attendant
at S hears in his telephone the word "busy" uttered by the phonograph.
There is further another active spring contact o in the said spring jack K. It
registers and connects with a side contact surface y of the plug P2; and this as
shown in the drawing is the normally discontinuous terminal of the circuit con-
ductor 12, leading through the visual indicator v (which may be a self restoring
annunciator or a glow lamp) to the battery F whose other pole is united to an
earth connection E. The circuit of the said battery thus is normally open.
By inserting the plug P 2 in the jack K, this circuit is closed through the
conductor 13 and through the automatic intermittent circuit breaking trans-
mitter B, to an earth connection E 2 and the conductor 13 is therefore a branch or
continuation circuit for the signalling circuit 12.
The signal transmitting device B may be a roller of nonconducting material
in which are inlaid conducting strips making intermittent connection with circuit
springs in a manner well understood, or it may be made in any well known way.
In operation it causes the visual signal indicator to flutter or tremble, and
since the signal is otherwise steady off, or steady on, the fluttering motion is always
understood to have some peculiar signification.
Of course instead of constructing this signal circuit of but one conductor, and
completing it through the earth, we may if we so desire, construct its continua-
tion circuit in loop form, as is done with the circuit c2 and in that case its con-
ductors would unite with the two spring jack contacts o and o2 instead of with o
alone as now shown; and in like manner there would be an associate conductor for
the conductor 12 which at one end would terminate in the plug contact surface w 2
and at the other would connect with the end of conductor 12 at that side of the
battery which now has the earth connection.
It is evident that the battery E may be placed at any point in the circuit either
of the conductor 12 or the continuation thereof 13.
Placing the plug P2 in the busy jack therefore completes both main and
signalling circuits, causing an oral or other audible signal to be automatically sent
to the station S which is manifested in the telephone and causing a visual signal
to be sent to the switch connection X which is manifested on the indicator v.
And as the signal transmitter B of the signalling circuit and that T or V of the
main circuit are controlled by the same switchboard apparatus, and operated by
the same action, we call them collectively a compound signal transmitter.
Dated this 13th day of May 1893.

page_text: COMPLETE SPECIFICATION.
Busy Signal for Telephone Circuits.
We, EDWARD JULIUS HALL, of Morris in the County of Morris and State
of New Jersey, and FRANK ALBERT PICKERNELL of Newark in the County of
Essex and State of New Jersey, United States of America, 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 :-
This invention relates to the transmission of signals on telephone circuits, and
has been found especially useful in connection with switchboards on which the same
main circuit is represented at more places than one, and which therefore are
necessarily to be supplied with some form of appliance for indicating at one point
on such a switchboard that a given circuit is busy at another point.
Its main object is to provide convenient and suitable means by the aid of which
the occupied state at one portion of a switchboard of a circuit with which
connection is desired may be automatically indicated to the operator at another
portion of said switchboard who is seeking such a connection, and also simul-
taneously announced (preferably in spoken words) to the customer or substation
attendant who desires to communicate, but the latter part of said operation alone
is also frequently useful and desirable.
The invention which we point out specifically in its several phases, in the
claims at the end of this Specification comprehends any main telephone circuit
which extends from a terminal station where is located a receiving telephone and
its concomitant apparatus to a suitable central or other opposite terminal station,
where it may be interconnected with others, or where alternatively it may readily
be united to a continuation loop or branch circuit containing a transmitter adapted
to act upon the said telephone receiver as soon as the said connection is made, and
to produce or reproduce therein an oral or audible signal having a preconcerted
meaning.
The said transmitter is preferably a transmitting telephone connected directly or
inductively in such continuation circuit, and mounted in intimate association with
a constantly operating phonograph which repeats any predetermined word or
phrase into the transmitter mouthpiece, and such word or phrase being reproduced
by the telephone receiver at the distant terminal station imparts any necessary
information to the listening operator or attendant there.
Instead however of a transmitter and phonograph an electrotome or other inter-
mittent or vibratory circuit breaker such as an ordinary buzzer may be employed
in which event of course the signal received by the said attendant at the terminal
station in his telephone or upon his bell will be a peculiar buzz, hum, ring or rattle,
constituting an arbitrary signal, having an understood meaning.
The invention also comprises the association with such a circuit, of an inter-
mediate station or switchboard connection through which it passes and whence
an independent signalling circuit extends to the terminal point of the main circuit,
a visual signal indicator included in said independent circuit at the intermediate
station, and an automatic intermittent circuit breaking transmitting device adapted
to effect changes of current in the said independent circuit to which the indicator
therein will respond. This signal transmitter as well as that of the main circuit
is included in a suitable branch or continuation circuit, and the two continuation
circuits may be, and preferably are provided with a single terminal spring jack
or plug socket within which the terminals of both are contained; both moreover
being normally open or discontinuous in the said spring jack but adapted to be
closed and to become operative upon the insertion within said spring jack of a
suitable plug connector.
The action of this independent circuit transmitter is to produce a trembling o

page_text: fluttering of the signal indicator, and thus to give a signal, which may by previous
understanding have any special meaning.
The said continuation circuits being thus provided with a compound signal
transmitter and with a common terminal spring jack, it is convenient to combine
the terminals of the telephone and signalling circuits in a common plug connector
adapted to be inserted in said jack and thereby to complete both circuits and
-operate both signals.
One useful adaptation of this invention is its application as a busy signal to
divided or multiple switchboards. The telephone circuit lending from a substation
may connect with two spring jacks at different portions of the switchboard.
"
or any
Should a station call for a connection with a second station which is found to be
busy, the plug terminal of the circuit of the first station may be placed in such a
continuation circuit spring jack as has been described, and by means of the
associated transmitter and phonograph, or other device the word "busy
-other prearranged word, phrase or other signal may be transmitted to the calling
station, and reproduced in the apparatus there, thus conveying the necessary
information to the customer in an unmistakeable way.
And in central stations where a calling circuit is to be connected with the
desired circuit through the intermediation of office trunks, the visual signal
indicator being placed at the call initiating end of such trunk, the plug connector
forming the remaining trunk terminal becomes virtually the terminal of the call
initiating circuit. When under these conditions the circuit desired is found to be
temporarily occupied with another .connection, and the terminal plug placed in the
compound continuation circuit jack, both continuation circuits will be simultaneously
closed and the compound transmitter becoming operative will cause the operation
of the audible signal at the call initiating substation and also the operation of the
visual signal at that end of the office trunk nearest thereto; the operators both
at the substation and at the central station being thereby both notified that the
desired connection cannot at present be had.
In a separate application for Letters Patent filed of even date herewith by
Edward J. Hall for a system of central station inter-communication comprising
-divided switchboards, on one of which incoming calls are received, while connections
with desired lines are made on the other, the same being entitled central office
apparatus and circuits for telephone exchanges, these utilizations of our invention
are described and certain combinations of which it forms an element are claimed.
The drawing (left with the Provisional Specification) which forms a part of this
Specification is a diagram illustrating conventionally the several arrangements of
circuits and apparatus which have generally been indicated above.
With the exception of the points marked S, S2, S3 and S4 which symbolize
sub-stations fitted of course with the usual telephones t, and telephonic appliances,
together with their respective main circuits C, C2, C3 and C4, each having direct
and return wires 6 and 7 the entire drawing indicates the circuits and apparatus of
a central station D.
Circumstances however frequently occur where a given circuit as C represented
at one part X of the central station requires to be connected by means of an office
trunk conductor Z with a second circuit C 2 or C3 at another part of the central
station or another portion Y of the switchboard.
Under such conditions the first point of connection (that is to say the switch-
board X where the call was received and where the work of connection was
initiated) is virtually an intermediate station on the circuit extending between the
substation S, and the switchboard Y on which are located the connection devices j
of the circuit wanted.
At the substation S, t is the receiving telephone, and is shown at the ear of a
customer A, who is supposed to have sent in an order for connection of a certain
line, and is now waiting to be told either that the connection is completed; or else
that the line wanted is occupied or busy. The terminal spring jack J of the
.substation circuit C is represented as having already received the answering plug

page_text: of the link connection N whose two conductors 8 and 9 are thus at one end'
connected with the two main circuit conductors 6 and 7, while at the other end they
terminate in conducting services and 92 of the plug P, that being adapted for
insertion in the spring jack k of the trunk conductor Z, but shown apart for
convenience of explanation.
The said jack has two spring contacts g and h which register and make contact
with the plug contact surfaces.
The spring contacts g and are the terminals of the two wires 10 and 11 of the
trunk conductor Z and extend to the Y part of the switchboard or office where
they connect respectively with the contact surfaces wo and of another plug
connector P 2 which forms the movable terminal of the said trunk conductor.
The plug P being thrust into the jack k, the surfaces w and of the other
plug P2 become at once the terminals of the substation circuit C, and the plug P 2
as a whole becomes the movable terminal of the said circuit; on which the switch
connections at X have also become practically an intermediate station.
If now the plug P2 be placed in the spring jack j of circuit C 2, its contact.
surfaces w and make contact with the spring contacts e and of said jack
establishing through communication between the substations S and S2 over the
two circuits C and C 2, the link connection N and the office trunk conductor Z.
At the
K is an auxiliary spring jack located at Y its form being similar to the others..
Its principal spring contacts m and n are united to the ends of two conductors 4
and 5 of a loop circuit c2 connecting with a signal transmitting device.
other end of such loop circuit I show as alternative signal transmitters, a telephone
transmitter T and a phonograph G mounted immediately in front of the mouthpiece
thereof; and a vibratory circuit breaker or buzzer V operated by an electro--
magnet 1 in a local circuit (not shown).
These devices may of course be connected either directly in the circuit c2, or
they may be, and preferably are connected as shown, in a local circuit c and
arranged to act upon the circuit c 2 through and by means of an induction coil I
which has its primary helix in the circuit c and its secondary helix in the-
circuit c 2.
To operate the buzzer V, the switch is placed on the button 3, and the buzzer
then intermits the circuit c of the battery L at the points u u 2 rapidly, and thereby
sends induced currents into the circuit c 2 in rapid succession, which if a telephone
be included in such circuit, will produce a loud buzz therein.
We prefer however for our present purpose to use the transmitting telephone T.
Any words spoken into this transmitter will of course induce voice currents by
means of the induction coil I in the circuit c 2. If a telephone be connected in
the said circuit, the words which originated such voice currents, will be reproduced
by their action therein, and a copy of the said words will be heard in the telephone.
The phonograph can readily of course be arranged to speak any words or phrases.
desired in the transmitter mouthpiece. We have used a phonograph in this.
association as a busy switchboard and station signal which we have equipped with
a cylinder repeating the word "busy" continuously.
For such work the form of metallic record employed in the process described in
Letters Patent of the United States No. 372,786 granted November 8, 1887 to
Emile Berliner would probably be well adapted.
The plug P 2 representing the terminal of the telephone circuit may be placed in.
the springjack K. When so placed, the circuit c2 may be regarded as a continuation
circuit of the circuit C, which is now extended to the transmitter T, and the words
uttered by the phonograph are heard in the telephone at S.
Considering the invention in its application to switchboards the jack K, may be
entitled the "busy jack," and several may be employed. When therefore it is
found that the circuit with which communication is required (say $2) is in use, the
plug is at once placed in the busy jack, and the customer or attendant at S hears
in his telephone the word "busy" uttered by the phonograph.
There is further another active spring contact o in the said springjack K. It

page_text: registers and connects with a side contact surface y of the plug P2: and this as
shown in the drawing is the normally discontinuous terminal of the circuit
conductor 12, leading through the visual indicator v (which may be a self.restoring
annunciator or a glow lamp) to the battery F whose other pole is united to an
earth connection E. The circuit of the said battery thus is normally open.
By inserting the plug P2 in the jack K, this circuit is closed through the
conductor 13 and through the automatic intermittent circuit breaking transmitter B,
to an earth connection E 2 and the conductor 13 is therefore a brauch or continuation
circuit for the signalling circuit 12.
The signal transmitting device B may be a roller of nonconducting material, in
which are inlaid conducting strips making intermittent connection with circuit
springs in a manner well understood, or it may be made in any well known way.
In operation it causes the visual signal indicator e to flutter or tremble, and since
the signal is otherwise steady off, or steady on, the fluttering motion is always
understood to have some peculiar signification.
Of course instead of constructing this signal circuit of but one conductor, and
completing it through the earth, we may if we so desire, construct its continuation
circuit in loop form, as is done with the circuit c 2 and in that case its conductors
would unite with the two spring jack contacts o and O2 instead of with o alone as
now shown; and in like manner there would be an associate conductor for the
conductor 12 which at one end would terminate in the plug contact surface to 2 and
at the other would connect with the end of conductor 12 at that side of the battery
which now has the earth connection.
It is evident that the battery F may be placed at any point in the circuit either
of the conductor 12 or the continuation thereof 13.
Placing the plug P 2 in the busy jack therefore completes both main and signalling
circuits, causing an oral or other audible signal to be automatically sent to the
station S which is manifested in the telephone t and causing a visual signal to be
sent to the switch connection X which is manifested on the indicator v.
And as the signal transmitter B of the signalling circuit and that T or V of the
main circuit are controlled by the same switchboard apparatus, and operated by the
same action we call them collectively a compound signal transmitter.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
1. The combination with the switch boards of telephone exchanges of a conductor
to which any of the line wires can be coupled and automatic transmitting mechanism
for transmitting continuously or at short intervals through the conductor and through
any lines coupled to it any prearranged signal for indicating at the ends of these
lines that the lines they are wishing to be coupled to are already occupied.
2. In combination with a main telephone circuit extending from a terminal
station through an intermediate station to a switchboard at which are located the
connection devices of other main circuits; an audible signal receiving instrument
at said terminal station; a visual signal receiving instrument at said intermediate
station; and a signal transmitting mechanism at said switchboard, adapted to
simultaneously operate the said visual and audible signal instruments; and thereby
to indicate at both terminal and intermediate stations that a given main circuit at
the said switchboard with which connection may be desired, is in use, substantially
as described.
3. In combination with a main telephone circuit extending from a terminal station
through an intermediate station or connection to a switchboard at which other main
circuits are represented by connection devices; a telephone apparatus included
therein at said terminal station an independent circuit associated with said main
circuit and extending from the said intermediate station to the said switchboard and
a visual signal indicator at said intermediate station responding to changes of current
in said independent circuit; a compound signal transmitter at said switchboard

page_text: connected with both of the said circuits and comprising an automatic arbitrary
signal or articulating transmitting appliance in the main circuit adapted to produce
vocal or other sounds in the telephone apparatus connected therewith and an
automatic intermittent circuit or vibratory circuit breaker or equivalent device in
the independent circuit adapted to produce a fluttering or equivalent action of the
said visual indicator included therein whereby a preconcerted signal may automati-
cally be sent to both intermediate and terminal stations simultaneously substantially
as described.
4. In combination with a main telephone circuit extending from a terminal station
through an intermediate station or connection to a switchboard at which other main
circuits are represented by spring jacks; a telephone included therein at said
terminal station; an independent circuit extending in association with said main
circuit between said intermediate station and switchboard and a visual signal
indicator at said intermediate station in said circuit adapted to respond to changes
of current occurring therein; transmitting mechanism at said switchboard connected
with both of the said circuits, and comprising a telephonic transmitter, and an
articulating phonograph therefor in the main circuit whereby articulate signals may
be sent to the terminal station and there reproduced in the said telephone, and an
automatic vibrator or intermittent circuit breaker in the independent circuit, adapted
to make and break the same and thereby operate the indicator at said intermediate
station, substantially as described.
5. The combination in a switchboard, of a connecting plug constituting the
movable terminal of two independent circuits containing signal receiving instruments;
a compound springjack adapted to receive the said plug, and containing the fixed
terminals of continuations of the said circuits and an automatic signal transmitting
device in each of the said continuation circuits, each adapted to be automatically
brought into operation by the insertion of said plug into the said spring jack, and
thereupon to actuate the signal device in its own circuit substantially as described
herein.
6. The combination of a series of switchboard connections at a central station ; a
series of circuits each extending from a receiving telephone at a substation to one
of the said central switchboard connections; an auxiliary switchboard connection,
constituting the terminal of a loop or continuation circuit containing a telephone
transmitter: a phonograph organized to report occupied circuits associated with
said transmitter, and adapted to operate the same; and means as indicated for
uniting the switchboard connections when unoccupied with one another, or, if the
desired connection he already in use, with the said auxiliary connection whereby a
verbal announcement of such busy condition may automatically be made in the said
receiving telephone; substantially as described.
7. The combination of a continuation branch or loop circuit including a telephone
transmitter, and provided with a phonograph associated with the said transmitter,
and adapted for the operation thereof; a similar continuation circuit including an
intermittent circuit breaker, or current varying device; and a springjack or equivalent
switchboard connection, containing the terminals of both of the said continuation
circuits, substantially as described.
8. The combination of a connecting plug constituting the movable terminal of a
circuit including a receiving telephone; with a spring jack adapted to receive the
said plug forming the fixed terminal of a loop or continuation circuit including a
transmitting telephone; and a phonograph associated with said transmitting
telephone and adapted to operate the same by repeating predetermined words or
phrases therein; substantially as specified.
1
Th
1004
CARPMAEL & Co.,
Agents for the Applicants.