Improvements in Telephone Installations and Apparatus therefor.
Year: 1897

page_text: Date of Application, 10th Mar., 1897
Complete Specification Left, 10th Dec., 1897-Accepted, 29th Jan., 1898
PROVISIONAL SPECIFICATION.
Improvements in Telephone Installations and Apparatus therefor.
We, SIEMENS BROTHERS & CO. LIMITED, of 12, Queen Anne's Gate, Westminster,
in the County of London, Electrical Engineers, do hereby declare the nature of this
invention (which has been communicated to us from abroad by Siemens and Halske,
of 94 Markgrafenstrasse, Berlin, in the German Empire, Electrical Engineers), to be
as follows:
This invention relates to an improved arrangement and construction of telephone
installations and apparatus, which is applicable either in its entirety as a complete
system, or parts thereof may be employed in combination with known systems. It
is based on the use of a two-cord system, a single line wire with indicators, contact
jacks, working with or without a test line, and magneto generators; the switch-
boards at the exchanges are of the table or horizontal type and a simple construction
of the several apparatus is aimed at.
The action of the entire system is such that firstly the connections for calling,
testing, speaking and indicator action are actuated by switches automatically worked
by the peg-cord weights and are also capable of being worked by hand for effecting
the extra-operations such as listening, &c. Secondly, the arrangement of the double
cord pegs and the testing key is such that the point of the calling peg serves for
raising the subscribers indicator, whereby one jack spring is done away with,
and that the current of the battery that serves both for the restoring and testing
passes through the speaking switch, while the point of the second peg serves for
testing.
We will describe the improved system of working with reference to the
accompanying diagrammatic drawings in which Figure shews the arrangement
without test-line, and Figure 2 the arrangement with test-line.
The line wires 1213 Figure 1 are, as heretofore, led through the jacks. (At the
subscribers stations there are control batteries). On a subscriber calling, the
indicator drop K¹ falls, the calling current passing through the row of jacks bb
through the drop coil F¹ of the indicator K' and to earth E.
The operator at the exchange inserts the calling peg S¹ into the calling jack
nearest the said indicator say in circuit thereby raising the spring away from
the socket 6 or jack body, and he can then at once inquire.
The connections are then as follows. The current passes through the line l
jacks b; b,
peg S¹, peg-cord 1, contact c 2 of switch U, left coil of the
head-gear receiver k to earth, and thence back to the subscriber.
On introducing the peg S¹ the subscriber's indicator drop K¹ is at the same
time raised again, a current from the + pole of the battery B passing over the
leads 2, and 3, restoring coil A' spring f point of peg S1 peg-cord 4 back to
the pole.
Any leak of the current which may occur from the spring through the point of
peg S to spring 2 and thence through the drop coil F to earth and back to
the pole of battery B, can be left out of consideration on account of the high
resistance of coil F¹ as compared with the existing short circuit through f¹, peg S¹

page_text: -
and leads 4 and 9 to the pole of the battery and earth. The levers of the
automatic switches U1 U2 belonging to S1 and S2 rise on lifting off the peg. The
operator receives the order, takes the second peg S3 and can at once test the line
required. If he finds this disengaged, he puts the peg S2 in the corresponding jack
and calls forward by means of the key T.
5
The course of the current on testing when the engaged line is to the left of the
pegged jack (such as line 3) is as follows: earth, controlling device of subscriber,
line, peg sockets b b .
to point of peg S³, line 5, right hand coil r of the
receiver k to earth. The course of the current on testing to the right of the pegged
jack is as follows:-From the + pole of the battery B through lead 6 to coil A 1 of 1
subscriber's indicator K¹ jack spring through insulated ring of the inserted
connecting peg S to spring f, to one of the right hand peg sockets b, point of the
testing peg S, lead 5, right hand coil of receiver k to earth, and, as the
pole is
put to earth, back to the battery B. The operator hears in both cases a crackling in
his telephone & if the lines are engaged. The connections that do not belong to the 1
regular sequence of a communication, such as listening, and raising a ring off
indicator dropped by repeated calling can be effected by depressing the automatic
switches and U* which are provided with a handle or button.
-
The course of the current on speaking (such as between subscriber's lines 12 and 1³,)
is as follows. Subscriber 3, line 1³, peg S¹, peg cord 1, (peg is lifted off and U2 is 2
interrupted at c² so that there is no leak) drop-coil of indicator K³, key T, lead 7,
peg Socket 7, line 12, ubscriber 2, to earth.
On ringing off, the magnet at F¨º is excited and the indicates K' drops.
On withdrawing the pegs S1 and S2 the restoring of the drop K is effected by
means of the switch U through S¹as a current from battery B is established for a 2
short time (during the passage of the switch U¹ over contact c¹) through + B, lead 8,
reversing contact c¹, restoring coil A³ of indicator K³, leading to B, while the inquiry
position is re-established by peg S².
Figure 2 shews an arrangement with special testing sockets or jacks X. A special
testing cell P at the exchange replaces that at the subscribers instrument.
The springs and the sockets 6 are connected together by the peg when this is
introduced, while the points of the pegs are free.
The courses of the currents are as follows:-
ENQUIRY. Peg S¹ is inserted in the calling jack X for instance in line 12.
3
The current passes from subscriber 2 through the line 2 jack springs ff to the 3
enquiry jack X, spring f³, body of peg S¹, peg-cord 1, through drop-coil F2 of
indicator K2, lead 2, key T, thence to reversing lever U2, contact c² left coil / of
receiver k to earth and thence back to the subscriber 2. On introducing the peg $1
the restoring is simultaneously effected of the subscriber's indicator drop K' which
fell at the call signal, the current from + B passing through leads 3 and 4, restoring 4
coil A¹, spring, point of peg S¹, peg-cord 5, lead 5, (the switch U will have risen
and U¹ is interrupted at c¹ so that no leak will pass through contact c³ of the
depressed switch Û² and lead to the pole of B.
-
TESTING. (with a line pegged such as with line 1). The current passes from
earth to subscriber 1, line jack springs f² f
through the body of an 4
inserted peg to one of the sockets b; thence through the row of sockets to the testing
socket, through the peg point S, cable 7 and lead 8 to the testing element P,
thence through lead 9 right hand coil r of receiver k, and back to earth.
SPEAKING. (such as between the subscribers lines 1 and 2). The current passes
from the subscriber 2 through line 2 row of jacks to the enquiry jack X, peg S¹, 5
peg-cord 1, drop-coil F2 of indicator K (without however actuating this) lead 2,
key T through the peg-cord to body of peg S2 (switch U2 is raised, because
peg S2
is lifted off, so that the leak through U to contact c² is interrupted), jack
spring 2, row of jacks, line ¹ to subscriber 1, and thence to earth and back to
subscriber 2.
E
RINGING OFF. The course of current is the same as with "speaking." The drop-
coil of K² is in this case actuated.

page_text: RESTORING INDICATOR DROP IN RINGING OFF.
On replacing the pegs S₁ and S2 the switches U¹ and U2 are pressed down
again, and contacts c¹ c² and c³ are closed, and a current passes from + B through
lead 10 through the restoring coil A2 of K2, thence through lead 11 contact c¹
switch U¹, lead 5 contact c³, lead 6 to - B.
LISTENING. The lever of the switch U² to peg S is depressed by hand. The
course of current is the same as in inquiry, with the exception that the second
peg S is inserted.
The constructions of the indicator and switch-boards at the exchanges are as
follows:-
The indicator-board is constructed as a glass case having a blackened glass front
with rectangular openings in which appear the numbers of the indicator-drops,
which disappear automatically after establishing the connection.
The back of the case carries horizontal metal rails serving as conductors on which
the indicators are fixed by means of screws. The peg-cords hang from the terminals
of the indicators. These can be removed from behind by loosening the terminals
and the screws securing them to the conducting rails.
The jack strips with their rows of jacks are not arranged parallel with the length
of the jack table as heretofore, but are arranged transversely across the same; they
preferably contain each two rows of ten jacks each, the numbering of which so as to
be easily read is thereby greatly facilitated.
The jack table is so constructed that all the subscribers jacks are arranged along
the middle part thereof; on each side of this on a somewhat lower level is a
horizontal switch-board with holes for the insertion of the pegs the lower ends of
which rest upon and depress the automatic switch levers through holes in the sockets
of which the weighted peg-cords pass. An inclined board projecting down from the
switch board contains the hand switches for the extra manipulations actuated by
buttons, and at the bottom of this inclined board is a horizontal board containing
the calling switches.
By the above described terrace-like arrangement of the table the advantages are
gained firstly that the operator can stand conveniently close to the subscriber's jacks,
without risk of interfering with the switches, and secondly that the entire table can
be conveniently enclosed by means of a hinged cover on each side, which turns down
so as to be quite out of the way.
The automatic speaking switches consist of spring blades that are pressed together
by the weight of the peg when inserted, and thus effect the herein before described
connections, which are interrupted on lifting off the peg. The attendant can then
close the switches by hand when required by depressing the buttons on the inclined
board.
The calling switches on the lowest board have three blade contact springs, so
arranged that the stem of the spring button when not depressed makes contact
between springs Nos. 1 and 2, while when depressed it makes contact between
Nos. 1 and 3.
In arranging the line cables directly below the jack tables in the ordinary manner,
the necessarily thick layer of cables entirely prevents all ready access to the jacks
from below, as the layer of cables must first be separated and removed before such
access can be gained; the arrangement also has the disadvantage that the jack table
has to be made inconveniently high, for enabling a workman to pass underneath the
table.
According to the present invention these inconveniences are avoided by arranging
the layers of subscribers cables vertically against the inner side walls of the table,
and from such layers the ends of the individual cables are led first vertically upward,
and then horizontally below each row of jacks, to which the separate wires of the
cables are then connected. By this means a clear space is formed below the table
for the workmen, and the height of the table can be considerably lessened.
Furthermore the jack table is formed transversely as two separate flaps, that can

page_text: turn up and over on hinges at the side so that by so raising the flaps the whole of the
jacks are accessible from the outside.
In an exchange according to this invention, the jack and switch tables are
preferably arranged in one or more long rows, while the indicator cases are arranged
in corresponding rows over the jack tables being conveniently suspended by brackets 5
from the roof.
Improvements in Telephone Installations and Apparatus therefor.
We, SIEMENS BROTHERS & CO. LIMITED, of 12, Queen Anne's Gate, Westininster, in
the County of London, Electrical Engineers, do hereby declare the nature of this
invention (which has been communicated to us from abroad by Siemens and Halske,
of 94, Markgrafenstrasse, Berlin, in the German Empire, Electrical Engineers) and in
what manner the same is to performed to be particularly described and
ascertained in and by the following statement:—
This invention relates to an improved arrangement and construction of telephone
installations and apparatus, which is applicable either in its entirety as a complete
system or parts thereof may be employed in combination with known systems. It is
based on the use of a two-cord system, a single line wire with indicators, contact jacks,
working with or without a test line, and magneto generators; the switchboards at
the exchanges are mainly of the table or horizontal type and a simple construction of
the several apparatus is aimed at.
The action of the entire system is such that firstly the connections for calling,
testing, speaking and indicator action are actuated by switches automatically worked
by the peg-cord weights and are also capable of being worked by hand for effecting
the extra operations such as listening, &c. Secondly, the arrangement of the double
cord pegs and the testing key is such that the point of the calling peg serves for
raising the subscribers indicator, whereby one jack spring is done away with, and that
the current of the battery that serves both for the restoring and testing passes
through the speaking switch, while the point of the second peg serves for testing.
We will describe the improved system of working with reference to the diagram-
matic drawings accompanying our Provisional Specification in which Figure 1 shews
the arrangement without test-line, and Figure 2 the arrangement with test-line.
The line wires 12 13 Figure 1 are, as heretofore, led through the jacks. (At the
subscribers stations there are control batteries). On a subscriber calling, the
indicator drop K¹ falls, the calling current passing through the row of jacks 6 b
through the drop coil F" of the indicator K¹ and to earth E.
The operator at the exchange inserts the calling peg S¹ into the calling jack nearest
the said indicator say in circuit thereby raising the spring away from the
socket bor jack body, and he can then at once inquire.
•
The connections are then as follows: The current passes through the line 18
jacks b; b,
peg S¹, peg-cord 1, contact c² of switch U2, left coil of the
head gear-receiver k to earth, and thence back to the subscriber.
On introducing the peg S¹ the subscriber's indicator drop K¹ is at the same time
raised again, a current from the + pole of the battery B passing over the leads 2,
and 3, restoring coil A¹ spring f¹ point of peg S¹ peg cord 4 back to the
pole.
Any leak of the current which may occur from the spring through the point
of peg S¹ to spring and thence through the drop coil Fi to earth and back to
the
pole of battery B, can be left out of consideration on account of the high
-
-

page_text: -
resistance of coil F¹ as compared with the existing short circuit through peg S
and leads 4 and 9 to the pole of the battery and earth. The levers of the
automatic switches U¹ U belonging to S1 and S2 rise on lifting off the peg. The
operator receives the order, takes the second peg S2 and can at once test the line.
required. If he finds this disengaged, he puts the peg S2 in the corresponding jack
and calls forward by means of the key T.
The course of the current on testing when the engaged line is to the left of the
pegged jack (such as line 2) is as follows: earth, controlling device of subscriber,
line (2 peg sockets b b
to point of peg S2, line 5, right hand coil 7, of the
receiver k to earth. The course of the current on testing to the right of the pegged
jack is as follows:-From the + pole of the battery B through lead 6 to coil A¹ of
subscriber's indicator K¹ jack spring f1 through insulated ring 2 of the inserted con-
necting peg S to spring, to one of the right hand peg sockets b, point of the
testing peg S², lead 5, right hand coil r, of receiver k to earth, and, as the pole is
put to earth, back to the battery B. The operator hears in both cases a crackling in
bis telephone if the lines are engaged. The connections that do not belong to the
regular sequence of a communication, such as listening, and raising a ring-off-
indicator dropped by repeated calling, can be effected by depressing the automatic
switches U¹ and U2, which are provided with a handle or button.
The course of the current on speaking (such as between subscribers lines 12 and 13)
is as follows: Subscriber 3, line ³, peg S¹, peg cord 1, (peg S2, is lifted off and U2, is
interrupted at c so that there is no leak), drop coil F2 of indicator K², key T, lead 7,
peg S2, socket b line 12, subscriber 2, to earth.
On ringing off, the magnet at F2 is excited and the indicator K2 drops.
On withdrawing the pegs S1 and S2 the restoring of the drop K² is effected by
means of the switch U' through S' as a current from battery B is established for a
short time (during the passage of the switch U' over contact c³) through + B, lead 8,
reversing contact c¹, restoring coil A2, of indicator K2, lead 9 to B, while the
inquiry position is re-established by peg S³.
Figure 2 shews an arrangement with special testing sockets or jacks X. A special
testing cell P at the exchange replaces that at the subscribers instrument.
The springs f and the sockets 6 are connected together by the peg when this is
introduced, while the points of the pegs are free.
The courses of the currents are as follows:-
Enquiry: Peg S' is inserted in the calling jack X for instance in line ².
The current passes from subscriber 2 through the line jack springs f f to the
enquiry jack X, spring f, body of peg S¹, peg-cord 1, through drop-coil F", of
indicator K2, lead 2, key T, thence to reversing lever U2, contact c², left coil of
receiver & to earth and thence back to the subscriber 2. On introducing the peg $1
the restoring is simultaneously effected of the subscriber's indicator drop K₁ which
fell at the call signal, the current from + B passing through leads 3 and 4, restoring
coil A¹ spring, point of peg S1, peg-cord 5, lead 5, (the switch U will have risen and
U is interrupted at c' so that there will be no leak) through contact of the
depressed switch U and lead 6 to the-pole of B.
Testing (with a line pegged, such as with line 1). The current passes from earth
to subscriber 1, line jack springs f²²².. through the body of an inserted peg
to one of the sockets b; thence through the row of sockets to the testing socket,
through the peg point S', cable 7 and lead 8 to the testing element P, thence
through lead 9 right hand coil r of receiver k, and back to earth.
Speaking (such as between the subscribers lines 1 and 2). The current passes froin
the subscriber 2 through line row of jacks to the enquiry jack X, peg S', peg cord 1,
drop-coil 2, of indicator K2 (without however actuating this) lead 2, key T, through
the peg-cord to body of peg S² (switch U2 is raised, because peg S2 is lifted off, so that
the leakage through U to contact & is interrupted), jack spring f², row of jacks,
line, to subscriber 1, and thence to earth and back to subscriber 2.
Ringing off: The cause of current is the same as with "speaking." The
drop coil F of K² is in this case actuated.

page_text: Restoring indicator drop in ringing off.
On replacing the pegs S1 and S2 the switches U¹ and U2 are pressed down again,
and contacts c c² and care closed, and a current passes from + B through lead 10
through the restoring coil A2 of K², thence through lead 11, contact c¹ switch UI
lead 5 contact c³, lead 6 - B.
Listening. The lever of the switch U to peg S2 is depressed by hand. The
course of current is the same as in inquiry, with the exception that the second peg S²
is inserted.
In arranging the line cables directly below the jack tables in the ordinary manner,
the necessaryly thick layer of cables entirely prevents all ready access to the jacks
from below, as the layer of cables must first be separated and removed before such
access can be gained; the arrangement also has the disadvantage that the jack table
has to be made inconveniently high, for enabling a workman to pass underneath the
table.
According to the present invention these inconveniences are avoided by arranging
the layers of subscribers cables vertically against the inner side walls of the table,
and from such layers the ends of the individual cables are led first vertically upward,
and then horizontally below each row of jacks, to which the separate wires of the
cables are then connected. By this means a clear space is formed below the table
for the workmen, and the height of the table can be considerably lessened.
Furthermore the jack table is formed transversely as two separate flaps, that can
turu up an over on hinges at the side so that by so raising the flaps the whole of
the jacks are accessible from the outside.
e
This arrangement of the cables relatively to the jacks so as to leave a clear
behind the latter, can be applied also to a vertical arrangement of the rows of
jack.
Figures 1 and 2 of the accompanying drawings shew respectively a part plan and across
section of a horizontal jack table with the cables arranged in the above described manner.
The switches U and pegs S₁ are arranged in the usual manner on side portions of the
table somewhat lower than the middle part carrying the jacks k contained in
jack plates F', each of which contains 20 jacks arranged in two rows, each plate being
connected at the outer end by a hinge joint to the side of the table, so that the
plates can be turned upon their hinges for inspection. The separate jacks are also
made moveable in their plates and can be taken out from the back when the plates
are turned up. The cables K are arranged against the side walls W of the table,
closely packed one against the other, their ends being first bent vertically upward
towards the top of the table and the several wires of the cable being separated from
each other they are then connected to the respective jacks. The space R thus
formed below the jacks constitutes a passage for the workmen where they can readily
gain access to the jacks, which access is greatly facilitated by arranging the plates "
to turn up on hinges, whereas with existing arrangements it was first necessary to move
aside the thick layer of cables underneath the jacks in order to gain access to the
jacks. The jack p'ates can be variously arranged; in the drawing they are
placed transversely of the length of the table, they might however also be arranged
longitudinally.
Figure 3 shews a vertical section of an arrangemennt in which the jack plates F
are arranged vertically in front of the switch table, the jacks being consequently
horizontal with the free space R for access situated behind them, the cables K being
arranged in suitably supported horizontal layers above and below such space.
Having now particularly described and ascertained the nature of the said invention
and in what manner the same is to be performed we declare that what we
claim is :-
1. A telephone installation characterised firstly by the use of double cord pegs, the
tips of which serve to raise the subscribers indicator drop, the current being made
to pass through the speaking switch and stopper cord, and which pegs are also used
for testing, while the body of the peg serves for forming the speaking connection

page_text: and characterised secondly by the use of two switches which are actuated on the one
hand by the peg weights for making the usual speaking connection, and on the other
hand are moved by the operator for inaking the exceptional connections, substantially
as described.
2. In combination with the arrangements referred to in the first claim, the
arrangement of the battery serving for raising the indicator drops, and for testing in
entire groups of instruments, with its one pole connected with earth and with the
point of the calling and drop raising peg while the other pole is connected to the
restoring coils of the subscribers and calling off indicator, the current being made to
pass from the subscribers indicator to parallel connected jack springs of each jack
and from the calling-off indicator to the switch with raising contact actuated by the
calling peg, the testing peg being provided between the point and the body with an
insulating ring for the purpose of connecting the jack spring connected in parallel
with the restoring and testing battery, with the opposite spring, substantially as and
for the purposes described.
3. In combination with the devices referred to in the first claim, the use of
separate restoring and test batteries, in combination with special test peg sockets,
the current being made to pass from the one pole of the restoring battery to the
restoring coils of the subscribers and calling-off indicators and from the subscribers
indicator to a spring of the calling jack connected with the point of the inserted
restoring and calling peg and thence to the other pole of the battery, while from the
calling off indicator the current passes to a contact of the switch actuated by the
ring off peg, a current being also made to pass from the point of the testing peg
through the testing battery and testing coil to earth, for the purpose of testing,
substantially as described.
4. An arrangement of jack board or table for multiple telephone systems, wherein
the cables are arranged against the sides of the board or table so as to leave the
space behind the jacks perfectly free for gaining access thereto, the board or table
being arranged either horizontally or vertically, substantially as described with
reference to Figures 1, 2 and 3 of the accompanying drawings.
Dated this 10th day of December 1907