Improvements in Telephone Systems of Exchange.
Year: 1896

page_text: Improvements in Telephone Systems of Exchange.
I, JOHN EDWARD KINGSBURY, of 79 Coleman Street, in the City of London,
Manager, do hereby declare the nature of this invention (which has been com-
municated to me from abroad by The Western Electric Company, of Chicago,
Illinois, United States of America,) to be as follows:-
This invention relates to a new organization of switch-boards for telephone
exchanges, whose object is to permit the distribution of subscribers' incoming
calls among the different operators with the purpose of economizing in the
operating force by keeping the operators uniformly and continually busy. A
multiple switchboard is used of substantially the ordinary character, in combination
with a call receiving or annunciator board at which all the subscribers' calls.
are received and from which they are distributed in a uniform manner to the
different operators at several multiple boards for the completion of the connection
with correspondent lines. Each telephone line is brought to a spring-jack or
similar switch connection, and to a suitable signal indicating instrument at the
call-receiving or annunciator board, and also to a line spring-jack or plug socket
on each of several multiple switch boards and a system of office trunk lines is
provided extending from the annunciator-board to each of the several multiple
boards whereby calls received at the annunciator board may be transferred to
operators at the several multiple boards and distributed equitably between them,
so that the work at the several boards may be equalized; the desired connections
being in each case completed by operators at the multiple boards in the usual way.
By observation or by information derived from suitable mechanism, the
annunciator board operator (who for distinction may be termed the switchman)
is kept informed as to the amount of work which the several operators have on
hand, and is therefore able to distribute incoming calls among the different
operators in an equalized or uniform manner, giving to each a fair share of the
work.
The apparatus comprises, then, an annunciator-board whereon is located an
annunciator, and a switch connection for each line; several multiple switchboards
each of which is provided with a line switch socket for each line; several office
trunk lines extending from the annunciator board to each of the multiple boards
and means for making connection between each terminal of the office trunk line
and any of the line switch sockets on the boards at both ends of the office
trunks.
The operator at the annunciator board is denominated the "distributing
operator," the other operators, who receive the subscribers' orders and make the
required connections are named "answering operators."
A system of signals under the observation of the distributing operator and
controlled by the answering operator, may be provided, by which the latter may
signalize to the former her readiness to answer calls; whereby the distributing
operator may be kept informed as to the busy or idle condition of the answering
operators, and may be able to so assign calls to each operator as to keep all
uniformly busy.
These signals may preferably be operated by the answering operator automatically
or incidentally in the performance of some manual act in the process of receiving

page_text: orders or making connections. In a satisfactory embodiment of this part of the
invention the signalling instrument is associated with the terminal plug of a trunk
line leading from the distributing operator to an answering operator, and is operated
by the listening key of the answering operator in the act of connecting her
telephone with the trunk line in position to receive orders. The display of a
signal then indicates to the distributing operator that the answering operator
attending the corresponding trunk line has her telephone connected with that line
and is free to receive orders. She will therefore connect the terminal plug with
the line of the next subscriber calling, after which the answering operator will
obtain the subscriber's order for the connection required, and will perform the
necessary acts to establish communication as demanded. The first movement of
the answering operator may cause the effacement of the signal before the
distributing operator, so that the disappearance of this signal will inform the
latter operator that the call has received attention.
Each answering operator is furnished with the usual telephone whose connection
with the trunk lines is controlled through a listening key. By means of this key
she may connect her telephone with any trunk line which has been or is to be
united with the line of a calling subscriber at the annunciator board, for the
purpose of receiving the subscriber's order.
A local signalling circuit may be provided in connection with the trunk line
which includes a signal instrument such for example as a lamp before the distributing
operator, and may be controlled by a suitable switch manipulated by the answering
operator.
This switch may be closed together when the listening key is brought into
position to connect the telephone with the trunk line. Means are provided also for
extinguishing the lamp at the proper time.
The operation of the signals is as follows: When an answering operator, having
performed all the work at hand, is ready to make further connections, she will
depress the plunger of her listening key, whereby her telephone will be brought
into circuit with the trunk line she is attending to and whereby at the same time
the signalling circuit will be closed and the lamp will be lighted. The illumination
of this lamp will be a signal to the distributing operator that the operator attending
to this trunk line is in position to receive calls, and she will insert the terminal
plug of this trunk line into the socket of the subscriber who next calls. The
subscriber will thus be placed in telephonic communication with the answering
operator. This operator will receive his order, and make the required connection.
The act of raising the plug to make the connection will interrupt the signalling
circuit so that the lamp before the distributing operator will be extinguished.
The obscuring of the lamp will signalize to the latter operator that the call has
received attention.
Any usual mode of transmitting signals for disconnection may be adopted, and
for notifying the distributing operator that the completed connection may be
removed.
In some cases the switching apparatus of telephone exchanges, is devised for
permitting a subscriber to designate to an attendant at a central station, a
particular group of subscribers among which the desired correspondent may be
⚫found. In exchange systems comprising several offices in which subscribers' lines
centre, the subscriber may thus designate the particular office in which the required
line terminates, the call being immediately trunked to an operator at the office
indicated.
The switching system comprising an annunciator or receiving board in which
the subscriber's line terminates in a signalling instrument, several switchboards,
each containing terminal connection sockets of a different group of lines, and office
trunk lines extending from the annunciator board to the switchboards with usual
plugs for making connection at the switchboards is used together with a signalling
instrument or indicator for each line at the annunciator board, controlled from the
substation, whereby the subscriber may indicate to the attendant at the annunciator

page_text: board the switchboard at which the line required terminates. This signalling device
may be any of the well known contrivances for designating a particular one of
several requirements by the display or actuation of an indicator by mechanism
controlled at the distant station. A form of the Wheatstone dial telegraph is
perfectly suitable for use in the present invention.
These trunk lines may be equipped with any of the well known devices for
informing the operator at the switchboards, automatically or otherwise, when
connection is made with the trunk line at the annunciator board, and for signalling
to the switchman at the latter board the disconnection of the trunk line at the
switchboard. The switchboards are supposed to be furnished with the usual
telephones, calling apparatus, and keys, for the use of the operators in establishing
connection with the lines.
In operating this system the subscriber must know what group or office forms
the terminal of the station with which he wishes to communicate. Suppose for
example any subscriber connected with an office A should wish to have his line
connected to any one or other of the subscribers connected with say an office B.
He will place the index of his transmitting instrument at B, whereby the index
of the corresponding receiving instrument in the annunciator board of his own
office will be caused to indicate B. At this signal the attendant switchman will
insert into the spring-jack of his line the terminal plug of the trunk line extending
to switchboard B and at this board it will be connected with line leading to office B,
or it may be connected by the switchman direct to a trunk line to office B. The
operator at office B having received information that the line of a calling subscriber
has been connected with the trunk line leading from A will bring her telephone
into circuit with that trunk line, learn from the subscriber the number of the
particular line with which connection is desired, and perform the required switching
in the usual way.
If the calling subscriber should require connection with a member of the same
group with himself, he would turn the index of his transmitting dial to A, to
indicate to the switchman that the call should be trunked to switchboard A ; or if
he should require communication with any station connected with C he would turn
the index to C and so on.
1000
COMPLETE SPECI
Improvements in Telephone Systems of Exchange.
I, JOHN EDWARD KINGSBURY, of 79 Coleman Street, in the City of London,
Manager, do hereby declare the nature of this invention (which has been com-
municated to me from abroad by The Western Electric Company, of Chicago,
Illinois, United States of America,) 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 a new organization of switch-boards for telephone
exchanges, whose object is to permit the distribution of subscribers' incoming calls
among the different operators with the purpose of economizing in the operating
force by keeping the operators uniformly and continually busy. A multiple
switchboard is used of substantially the ordinary character, in combination with a
call receiving or annunciator board at which all the subscribers' calls are received
and from which they are distributed in a uniform mauner to the different operators
at several multiple boards for the completion of the connection with correspondent

page_text: lines. Each telephone line is brought to a spring-jack or similar switch connection,
and to a suitable signal indicating instrument at the call receiving or annunciator
board, and also to a line spring-jack or plug socket on each of several multiple switch
boards and a system of office trunk lines is provided extending from the annunciater
board to each of the several multiple boards whereby calls received at the
annunciator board may be transferred to operators at the several multiple boards
and distributed equitably between them, so that the work at the several boards may
be equalized; the desired connections being in each case completed by operators at
the multiple boards in the usual way.
By observation or by information derived from suitable mechanism, the annun-
ciator board operator is kept informed as to the amount of work which the several
operators have on hand, and is therefore able to distribute incoming calls among
the different operators in an equalized or uniform manner, giving to each a fair
share of the work.
The apparatus comprises, then, an annunciator board whereon is located an
annunciator, and a switch connection for each line; several multiple switch boards
each of which is provided with a line switch socket for each line; several office
trunk lines extending from the annunciator board to each of the multiple boards
and means for making connection between each terminal of the office trunk
line and any of the line switch sockets on the boards at both ends of the office
trunks.
The apparatus is illustrated in Figure 1. Five substations A, B, C, D and E
are represented, each connected by a telephone line, the lines being desig-
nated 1, 2, 3, 4 and 5, respectively-with the switching apparatus at a central
station F. Line 1, for example, is connected with a spring jack or connection
socket a and with an annunciator a2 on the annunciator board f, and with spring
jacks a³, a and a upon the three sections 2, 3 and of the multiple board.
Trunk lines 6 and 7 extend from the annunciator board f to the section of the
multiple board, terminating in plugs and 2, by means of which they may be
placed in connection with the spring jacks. Other trunk lines 8 and 9 extend from
annunciator board f to the multiple section f³, and still others 10 and 11 from the
board f to the multiple section f^.
A call signal from station A will be indicated by annunciator a² at the
annunciator board f. The attendant stationed at that board, observing this signal,
will insert plug h of trunk circuit 6 into the spring jack a of that line, and then in
any suitable manner will inform the operator at section f that connection has been
made with trunk line 6. The operator at that board will obtain from subscriber
at station A the order for the required connection,-say with station B. She will
then complete the connection by inserting terminal plug h of trunk line 6 into the
spring jack ³ of line 2.
Immediately succeeding the call from station A a call from station C may be
received at annunciator board f. The attendant at that board is aware that
operator at section 2 is in the act of completing a connection, and accordingly will
use the terminal plug h of trunk line 8 to effect connection with spring jack c.
This connection will then be transferred to the operator at section f³ and will be
completed there. Another call received at annunciator board f may be transferred
to an operator at section f by means of trunk line 10; still another would be sent
to the first operator at section 12, after sufficient time has been given for the
completion of the first connection by that operator. By thus switching different
calls for answering and attendance to the operators at the different sections of the
multiple board, having constantly in mind the business on hand for each of the
operators, the attendant is enabled to equalize the work of the different operators.
They may all thus be kept continuously and uniformly busy, in which condition as
is well known, they perform their work most efficiently and quickly.
The operator at the annunciator board is denominated the "distributing operator,"
the other operators, who receive the subscribers' orders and make the required
connections are named "answering operators."

page_text: A system of signals under the observation of the distributing operator and
controlled by the answering operator may be provided, by which the latter may
signalize to the former her readiness to answer calls; whereby the distributing
operator may be kept informed as to the busy or idle condition of the answering
operators, and may be able to so assign calls to each operator as to keep all
uniformly busy.
These signals may preferably be operated by the answering operator auto-
matically or incidentally in the performance of some manual act in the process of
receiving orders or making connections. In a satisfactory embodiment of this part
of the invention the signalling instrument is associated with the terminal plug of a
trunk line leading from the distributing operator to an answering operator, and is
operated by the listening key of the answering operator in the act of connecting
her telephone with the trunk line in position to receive orders. The display of a
signal then indicates to the distributing operator that the answering operator
attending the corresponding trunk line has her telephone connected with that line
and is free to receive orders. She will therefore connect the terminal plug with
the line of the next subscriber calling, after which the answering operator will
obtain the subscribers' order for the connection required, and will perform the
necessary acts to establish communication as demanded. The first movement of
the answering operator may cause the effacement of the signal before the dis-
tributing operator, so that the disappearance of this signal will inform the latter
operator that the call has received attention.
Since the equipment and connections of the different lines are alike, those only
of one are shown in the drawings.
Each answering operator is furnished with the usual telephone k whose connection
with the trunk lines is controlled through a listening key l. By means of this key
she may connect her telephone with any trunk line which has been or is to be
united with the line of a calling subscriber at the annunciator board, for the
purpose of receiving the subscriber's order.
A local signalling circuit 12 may be provided in connection with the trunk line
which includes a signal instrument such for example as a lamp m before the
distributing operator, and may be controlled by a suitable switch manipulated by
the answering operator.
This switch consists of a switch spring and its anvil 12 placed on the listening
key so that they may be closed together when the listening key is brought into
position to connect the telephone k with the trunk line. Means are provided also
for extinguishing the lamp m at the proper time.
For this purpose the circuit is continued through the switch contacts of a plug-
seat-switch n for the plug 2, the switch being adapted to open the circuit when
the plug is removed from its socket. A source of current o is included in the
signalling circuit.
The operation of the signals is as follows. When an answering operator, having
performed all the work at hand, is ready to make further connections, she will
depress the plunger of her listening key 1, whereby her telephone will be brought
into circuit with the trunk line she is attending to and whereby at the same time
the signalling circuit 12 will be closed at the contacts/ and the lamp m will be
lighted. The illumination of this lamp will be a signal to the distributing operator
that the operator attending to the trunk line 6 is in position to receive calls, and
she will insert the terminal plug of this trunk line into the socket of the
subscriber who next calls. The subscriber will thus be placed in telephonic
communication with the answering operator. This operator will receive her
order, and will raise the plug to make the required connection. The act of
raising the plug to make the connection will interrupt the signalling circuit 12 at
the contacts of the switch n so that the lamp m before the distributing operator
will be extinguished. The obscuring of the lamp will signalize to the litter
operator that the call has recived attention.
Any usual mode of transmitting signals for disconnection may be adopted, and

page_text: for notifying the distributing operator that the completed connection may be
removed.
In some cases the switching apparatus of telephone exchanges, is devised for
permitting a subscriber to designate to an attendant at a central station, a
particular group of subscribers among which the desired correspondent may be
found. In exchange systems comprising several offices in which subscribers' lines
centre, the subscriber may thus designate the particular office in which the required
line terminates, the call being immediately trunked to an operator at the office
indicated.
The switching system comprising an annunciator or receiving board in which the
subscriber's line terminates in a signalling instrument, several switchboards, each
containing terminal connection sockets of a different group of lines, and office
trunk lines extending from the annunciator board to the switchboards with usual
plugs for making connection at the switchboards is used together with a signalling
instrument or indicator for each line at the annunciator board, controlled from
the substation, whereby the subscriber may indicate to the attendant at the
annunciator board the switchboard at which the line required terminates. This
signalling device may be any of the well known contrivances for designating
a particular one of several requirements by the display or actuation of an indicator
by mechanism controlled at the distant station. A form of the Wheatstone dial
telegraph is perfectly suitable for use in the present invention.
This improved switching system is illustrated in Figure 2, in which a number of
subscribers' lines are represented connected with the switching apparatus of the
exchange offices. The drawings show only three of the subscribers' lines as being
provided with indicators and connection sockets upon an annunciator board, as
sufficient for the purposes of illustration, it being obvious that the other lines
represented on the drawings may be provided with similar indicators and connections
at the same annunciator board, or at another but similar one.
There are in the exchange system here shown, three switchboards A, B, and C,
which may be assumed to be located at different offices, and an annunciator board D,
which may be in the same office with switchboard A. The three substations E, F,
and G, are equipped with transmitting instruments of the dial telegraph,
represented in the drawings by the dial and index only. These stations are
connected by lines 1, 2 and 3, each with a connection socket d and a dial receiving
instrument d² in the annunciator board D, and each with a connection socket a, in
the switchboard A. Lines 4 and 5 from substations H and I lead each to a
connection socket 6 in switchboard B; and lines 6 and 7 to connection sockets c in
switchboard C.
One or more inter office trunk lines 8 extend from annunciator board D to
switchboard A, terminating in the usual plugs m and m³ for making connection
with the sockets. Another trunk 9 extends from board D to switchboard B, and
still another 10, from the annunciator board to switchboard C.
These trunk lines may be equipped with any of the well known devices for
informing the operator at the switchboards, automatically or otherwise, when
connection is made with the trunk line at the annunciator board, and for signalling
to the switchman at the latter board the disconnection of the trunk line at the
switchboard. The switchboards are supposed to be furnished with the usual
telephones, calling apparatus, and keys, for the use of the operators in establishing
connection with the lines.
In operating this system the subscriber must know what group or office forms
the terminal of the station with which he wishes to communicate. Suppose for
example any subscriber say E connected with the office A should wish to have his
line connected to any one or other of the subscribers say H connected with say the
office B. He will place the index of his transmitting instrument at B, whereby
the index of the corresponding receiving instrument in the annunciator board D of
his own office will be caused to indicate B. At this signal the attendant switchman
will insert into the spring-jack d of his line the terminal plug m of the trunk line 9

page_text: extending to switchboard B. The operator at office B having received information
that the line of a calling subscriber has been connected with the trunk line 9 will
bring her telephone into circuit with that trunk line, learn from the subscriber the
number of the particular line with which connection is desired, and perform the
required switching in the usual way.
If the calling subscriber should require connection with a member of the same
group with himself, he would turn the index of his transmitting dial to A, to
indicate to the switchman that the call should be trunked to switchboard A; or if
he should require communication with station K or L he would turn the index to C
and so on.
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 combination, an annunciator switchboard containing a connection socket
and an annunciator for each telephone line of the exchange, a multiple switchboard
of several sections each having in it a terminal connection socket of each line of
the exchange, and trunk lines extending from the said annunciator-board to each
section of the said multiple board, as described.
2. The combination with an annunciator board in which are located the
annunciators and terminal sockets of a number of telephone lines, answering
boards in each of which are located terminal spring-jacks of said lines, and trunk
lines from the annunciator board to the different answering boards, of a signal at
the annunciator board for each answering board, and means for exciting each of
said signals controlled at the corresponding answering board, substantially as
described.
3. The combination with an annunciator board wherein are located the
annunciators and terminal sockets of a number of telephone lines, answering
boards whereon are located terminal spring jacks of each of said lines, and
trunk lines from the annunciator board to the different answering boards, of a
switch at the answering board for each trunk line actuated by the answering
operator preliminary to making a connection, and a signalling circuit from each
answering board including a signal at the distributing board, said circuit being
controlled by the said switch at the answering board, whereby the readiness of
an answering operator to receive calls is signalled to the distributing operator, as
described.
4. The combination with an annunciator board wherein are located the
annunciators and terminal sockets of a number of telephone lines, answering
boards whereon are located terminal spring jacks of each of said lines, and trunk
lines from the annunciator board to the different answering boards, of an
operator's telephone at each answering board, a listening key for each trunk line
adapted to connect the said telephone with the trunk line, and a signalling circuit
including a signal at the annunciator board, controlled by switch contacts on the
listening key, substantially as described.
5. The combination with a switching system comprising an annunciator board on
which are located an annunciator and a socket for each line, a number of answering
boards on each of which are located sockets for different lines, and a trunk line
from the annunciator board to each answering board, of a signalling circuit
associated with each trunk line and including a signal at the annunciator board, and
a switch controlling the continuity of said signalling circuit at the answering board,
substantially as described.
6. The combination with a switching system comprising an annunciator board
in which are located an annunciator and a terminal socket for each line, answering
boards in each of which are located terminal sockets for different lines, and
trunk lines from the aununciator board to the different answering boards, of a
signalling circuit associated with each trunk line including a signal at the
annunciator board, an operator's telephone switch for the trunk line at the

page_text: answering board, and switch contacts adapted to close the signalling circuit
when the telephone is brought into circuit with the trunk line substantially as
described.
7. The combination with a switching system comprising an annunciator board
whereon are located an annunciator and terminal socket for each line, answering
boards on each of which are located terminal sockets for the lines, and trunk lines
from the annunciator board to the different answering boards, of a signalling circuit
associated with each trunk line including a signal at the annunciator board, an
operator's telephone switch for each trunk line at the answering board, switch
contacts adapted to close the signalling circuit corresponding to any trunk line
when the telephone is brought into circuit with the said trunk line, and a switch
for each trunk line at the answering board operated in making connection with the
subscriber's line, adapted to efface the corresponding signal, substantially as
described.
8. In combination, several telephone lines extending to terminal connection
sockets, an indicator for one of the lines adapted to indicate any of several objects,
means for controlling the indicator from the substation of the line, and switching
apparatus for making connection from the socket of the line having the indicator
to the terminal socket of any other line, as described.
9. In combination, several telephone lines terminating in connection sockets on
.different switchboards, an indicator adapted to indicate any of several objects for
one of the lines in an annunciator board and means for controlling the indicator
from the substation and trunk lines from the annunciator board to each of the
switchboards as described.
10. In combination, telephone lines each extending to a connection socket and an
indicator at an annunciator board, said indicator being adapted to designate any
of several objects, means at each substation for controlling the corresponding
indicator, other telephone lines terminating in connection sockets in different
switchboards, trunk lines extending from the annunciator board to each switch-
board, and switching apparatus at the annunciator board and at the switch-
boards for making connection between any trunk line and any socket, as
described.
J. E. KINGSBURY.