Improvements in Telephone Exchange Systems.
Year: 1894

page_text: Date of Application, 2nd Jan., 1394-Accepted, 25th May, 1894
COMPLETE SPECIFICATION.
Improvements in Telephone Exchange Systems.
I, ROMAINE CAllender, residing at Numbers 36 and 38 Dufferin Avenue,
Brantford, Ontario, Dominion of Canada, Electrician, 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 :—
My invention is directed particularly to improvements in that type of apparatus
known in the art as automatic telephone exchange systems in which the subscribers
through the agency of apparatus located at outlying stations and additional
apparatus located at a central or main exchange, are enabled to automatically
effect intercommunication with each other in any desired order, and its
objects are:
:
First, the construction of such an automatic telephone exchange system as will
enable any subscriber to instantaneously effect automatically intercommunication
through a central exchange office with any other subscriber and at the same time
prevent the possibility of any disturbance or interruption from a third subscriber
until after the first two have held their conversation or been " rung off" Second,
to provide means whereby a preliminary signal is first sent in to the central station,
all of the lines disconnected from a common switching device and finally to connect
the lines desired automatically: Third, to provide means whereby any two lines
of an indefinite number may be automatically connected on sending a simple make
and break signal from any outlying station to the central station: Fourth, to
provide means whereby the subscriber signalling may make the connection desired
from his own office through the central office over his own line by simply turning
in a signal from a transmitter located in or near his own telephone box: Fifth, to
provide means whereby when a signal is turned in, a constantly operating generator
located in the central station may be automatically connected in circuit with the
line of the subscriber sending the signal and that of the subscriber signalled and
the call bells at both stations rung, thereby indicating that the two lines are in
circuit: Sixth, to provide automatic mechanism which shall limit the time of the
conversation between the two subscribers and automatically cut their instruments
out of circuit and restore the apparatus at the central station to normal condition
on the expiration of the time limit: Seventh, to provide mechanism which shall
enable any subscriber to connect his line with that of any subscriber automatically;
to signal the subscriber wanted and finally after the conversation has been effected
to automatically ring off both subscribers and restore the lines to their normal
condition: Eighth, to provide mechanism in the nature of automatic apparatus
whereby any two or more subscribers having telephone instruments located on any
two of an indefinite series of outlying telephone lines connected with switching
mechanism at a central station may effect any of the results necessarily attributable
to the apparatus hereinafter described, the novel features of which are particularly
pointed out in the claims at the end of this Specification.
I accomplish these several objects with the apparatus hereinafter described, for
a full and clear understanding of which reference is had to the accompanying
drawings in which,
Figures 1, 2, 3, 4, 5, 6, 7 and 8 are diagrammatic views illustrating the entire
system and for a clear understanding of which the first eight of the sheets of the
drawings should be read as though laid side by side in sequence.
Figure 9 is a part diagrammatic part plan view of that portion of the apparatus
which chall torm the "icolator”

page_text: Figure 10 is a detail end elevational view of the circuit controlling apparatus
which regulates the releasing mechanism of the several portions of the clock or
time controlled apparatus.
Figure 11 is a plan view of the general switching mechanism whereby all of the
lines which enter the exchange are automatically interrupted when a preliminary
signal is sent in from a subscriber and remain interrupted during the time that the
automatic connection is being effected between the subscriber who signals and
the subscriber signalled.
Figures 12 and 13 represent diagrammatically a complete system of nineteen
lines showing the circuit connections from nineteen outlying stations to and through
the automatic central station with so much of the controlling apparatus as directly
influences the switching portions of the mechanism, and also illustrating in the
latter figure the radiating system of connecting conductors for connecting up
additional lines.
Figure 14 is a diagrammatic view illustrating the circuit connections in the
central station for a system of nine-hundred and ninety-nine lines, the operating
apparatus not being shown.
Before entering upon a detailed description of the drawings in order that a
general understanding may be had of my novel automatic system, it may be well
at the outset to indicate that all of the automatic apparatus in the nature of
switching apparatus, time controlled mechanism and the magneto call generator
are located at the central or main office into which the subscribers' lines all enter,
there being one or more sets of subscribers' instruments located on each independent
line, each of which sets of instruments is provided with a circuit breaking
transmitter like that shown in Figure 1 and lettered T, there being also a signalling
battery BA for each independent line earthed at E'.
All of the apparatus therefore shown in Figures 2 to 11 inclusive is located at
the central station and all of the incoming independent wires on which the
subscribers' instruments are located run to a rotary or oscillating general circuit
breaking cylinder C³, Figures 5, 11 and 13, their electrical continuity being
maintained through a series of metallic contact plates or strips e³ on the upper
surface of this cylinder.
In order to simplify the illustration, I have shown a single outlying line
numbered 1, Figure 1, earthed at E2 and provided with the usual lightning
arrester L, Blake transmitter T2, transmitting battery B A¹, receiving magneto
telephone T hung upon its hook in the ordinary way all of the circuit connections
thereof for the transmitter T2 and receiver T¹ being as is now well understood by
those skilled in the art, the right hand side of the lightning arrester L being
connected by the subscribers' line 1 to and through the upper portions of
Figures 2, 3 and 4 to the general circuit breaker C³ (Figures 5, 11 and 13) through
the contact springs, metallic plates e³ to No. 1 of a series of contact plates
numbered from "0" to "9" which in turn are connected through corresponding
subscribers' wires and similar apparatus located at outlying stations.
In the
telephone box of each subscriber or at some point casily accessible to the
subscriber is located a rotary transmitter T consisting of an insulating cylinder
having a series of ten metallic strips d and successively of different lengths located
upon the surface and electrically in contact with the metallic axis of the cylinder
which in turn is connected through a contact spring y with a signalling battery BA
earthed at E'.
The number of these metallic plates a is equal to that of a corresponding set of
conducting springs a¹ the free ends of which are adapted to bear upon the cylinder T
and make contact in succession with the plates a, while their other ends are
secured to a fixed set of electrical conducting plates numbered "0" 1, 2, 3, &c.,
to 9 inclusive, said contact plates being lettered o aud corresponding in number with
the number of subscribers' lines under the control of the first portion of the
apparatus at the central station which I denominate as "numerical receiver No. 1,"
see Figures 5 and 13.

page_text: S is a rotating conducting switch the free end of which is adapted to contact
with the ends of the conducting plates o, and M B is a magneto call electrically
connected on one side to the lightning arrester L with the earth E³ and on the
other through a pair of conducting springs t' with a short conducting plate i carried
by the cylinder T and in turn through the telephone hook with the subscribers'
line 1 as clearly shown.
The rotary transmitter T with the transmitting battery BA and the circuit
at the
connections just described constitute the only apparatus used by me
subscribers' stations for effecting automatic intercommunication through a central
station with outlying subscribers or independent lines.
I shall now describe in general terms the apparatus located at the central station
after which I shall describe the mode of operation of the entire system.
In Figure 6 is shown at the bottom of the drawing, a battery B² A² and a
series of circuits numbered 12, 7, 14, 17, 22 and 24 running to step by step
mechanism illustrated in Figures 2, 3, 4, 5, 7, 8 and 13. These several circuits
are automatically opened and closed at the points 99 by one or more conducting
extensions m of a pendulum R' carried by a clock beating seconds or any preferred
elements of time, p being the pendulum ball. I have shown this method of
closing these several circuits by a single conducting extension m and through the
agency of a pendulum for the reason that this is the simplest method of illustrating
this portion of the apparatus.
It will be understood that it would of course be preferable to provide independent
circuit closing contacts for each circuit 12, 7, 14, 17, 22 and 24 and that the
circuits might be closed with sliding contacts carried by a rotary drum adapted to
make one revolution in any desired time or that there might be a separate
rotary drum for each set of contacts and each controlled by an independent clock
mechanism and adapted to rotate each at such a speed as the necessities of the case
might demand.
Referring now to Figures 2, 3, 4, 7 and the lower part of 8. That portion of the
apparatus which discloses ratchet wheels or ratchet sectors with holding and
propelling pawls and operating electro-magnets together with releasing devices are
all controlled directly in their forward action step by step by the clock mechanism
shown in Figure 6.
That portion of the apparatus at the bottom of Figure 2 lettered E, I term the
"general time limit apparatus," its object being to operate for a specified length of
time under the control of the clock (Figure 6) during which time the subscriber
shall have had an opportunity to complete his signal and make the circuit connection
with the subscriber sought, after which this portion of the apparatus is automatically
released and conversation proceeded with as will be fully described later on.
That portion of the apparatus illustrated in Figure 3 by the letter C¹ I denominate
as the "
magneto signalling controlling instrument," its function being to auto-
matically connect the constantly driven magneto signalling generator H in a looped
circuit between any two subscribers' lines after they have been automatically
connected together through the central station.
That portion of the apparatus represented at the bottom of Figure 4 and
lettered C² I denominate as the "numerical separator," its function being to enable
any subscriber to select a certain one of the remaining subscribers' lines where the
total number of those lines amounts to more than 9: That is to say, by the use of
the switch S and the transmitter T for one revolution of said transmitter the
subscriber may connect his line with the desired one of the lines 0 to 9 in Figure 5,
but when the outlying subscribers' lines amount to more than 9 it will be necessary
to make two or more revolutions of the transmitter T and to correspondingly
1 to 9
change the location of the switch Sw to any one of the desired numerals 0, and 1
inclusive, between which revolutions of the transmitter this and other like numerical
separators act to aid in bringing about the desired connection as will be fully
described in connection with the description of the mode of operation.
To make this statement last made more clear, it is to be understood that

page_text: for the first system of outlying subscribers' wires illustrated in Figure 5, the switch
handle S is to be placed upon that one of the conducting strips 0 to inclusive
corresponding to the subscribers' wire wanted and one revolution given to the
transmitter T by the handle H and that for connections between the subscriber and
any higher number of outlying subscribers' circuits such as is shown in Figure 8, the
switch handle S would be placed upon any one of the conducting strips 0 to 9
corresponding to the subscribers' wire wanted in the higher number than 9 and the
transmitter T given a second rotation. In the meantime the numerical separator
illustrated at the bottom of Figure 4 will select the circuits of the higher order of
numerals from those of the lower order of numerals during the interval of time
between the two rotations of the transmitter T as will be fully described in the
description of the mode of operation.
That portion of the apparatus illustrated in the upper portion of Figure 5,
I denominate as "numerical receiver No. 1." It consists of a ratchet wheel W
and conducting arm D, operating electro-magnet R* and releasing electro-magnet d",
propelling pawl, holding pawl k³ releasing cord e passing under pulley * and
releasing armature 1, W2 being a weight attached to a cord passing over a pulley n
and secured to the shaft of the wheel W, the function of the conducting arm D
being to convey the current from the subscribers' wire one to the desired outlying
subscriber whose wire is connected with one of the conducting plates 0 to 9 inclusive.
This numerical receiver is positively propelled by the action of the electro-
magnet R and pawl through current impulses sent over the signalling subscribers'
line by the transmitter T when rotated, as already described.
That portion of the apparatus illustrated at the bottom of Figure 5, I denominate
as the "general circuit breaking instrument," the same being illustrated in plan
view in Figures 11 and 13 and controlled by electro-magnets do and do, armature
levers 1, 1, propelling pawl / and releasing pawl k*, releasing cord e passing under
the pulley b
That portion of the apparatus illustrated in the upper portion of Figure 7 and
lettered C, I denominate as the "adjustable automatic conversation time-limit
mechanism," its function being to regulate the time for which the conversation
between the subscribers may be held, and it is controlled by electro-magnets d', d",
and d with propelling pawl 0, releasing pawl k³, releasing cord passing under
pulley 66.
That portion of the apparatus shown at the bottom of Figure 7 and lettered C+,
I denominate as the "automatic release controller" which releases all of the
apparatus not already released when the adjustable automatic conversation time-
limit restores all of the apparatus at the central station to normal condition ready
for the next signal.
That portion of the apparatus shown near the top of Figure 8, I denominate
"numerical receiver No. 2," it being a mere extension of the like portion of the
apparatus shown in Figures 5 and 13, and denominated "numerical receiver No. 1,"
each one of the several subscribers' lines numbered from 1 to 9 inclusive, Figures 5
and 13, being connected to an instrument like "numerical receiver No. 1." In
other words each subscriber's line running out from "numerical receiver No. 1" in
Figure 5 would be connected to a corresponding conducting arm D' on a second
"numerical receiver" adapted to be connected with any one of a secondary set of
subscribers, like that shown in Figures 8 and 13, thereby largely increasing the
connecting capacity of the system.
A more clear understanding may be had of the arrangement of the numerical
receivers or switching, apparatus which connects up the various lines with each
other, on examination of Figure 14, where the first numerical receiver or numerical
receiver No. 1. is shown at the bottom of the drawing, and through which all
incoming signals pass for all lines of the entire system. The second series of
numerical receivers, each of which is always denominated as numerical receiver No. 2,
whenever referred to in this Specification, is seen immediately above numerical
receiver No. 1; and the third series of numerical receivers, each of which is always

page_text: denominated as numerical receiver No. 3, whenever referred to in this Specification,
is located above the second series and all signals of the third order of decimals pass
these receivers, as will be more clearly understood in connection with the description
of the mode of operation.
This figure of the drawings just referred to shows the circuit connections only
for the entire system of lines and the numerical receivers for connecting them
together in pairs in any desired order, it being understood that any incoming
signal from any outlying subscriber is conveyed first to numerical receiver No. 1,
thence through that one of the second series of numerical receivers denominated as
numerical receiver No. 2 which is called, and thence through that one of the third
series of numerical receivers which is called, it being understood that all lines
from 1 to 9 inclusive may be called through numerical receiver No. 1 only while
all lines from 1 to 99 inclusive are connected with each other only through
numerical receiver No. 1 and the necessary one of the second series connected to the
line wanted.
In other words all incoming signals of any nature whatever must pass through
numerical receiver No. 1. All incoming signals of the second order of decimals
or from 1 to 99 inclusive must pass through numerical receiver No. 1 and one
of the second series of numerical receivers. All signals from 1 to 999 inclusive
must pass through numerical receiver No. 1, some one of the second series of
numerical receivers and some one of the third series of numerical receivers.
That portion shown at the bottom of Fig. 8 of the drawings is a duplicate
numerical separator and is identical with that shown at the bottom of Fig. 4 of the
drawings lettered C².
Referring now to Fig. 2: L L are switches controlled by magnets M¹ M².
d³ is a releasing magnet for releasing the weighted switch lever 12, there being one
of these releasing inagnets for each subscriber's line and all operatively connected
with the circuit 8 with the releasing mechanism controlled by the adjustable
automatic conversation time-limit apparatus illustrated in Fig. 7. S₁, S and S6,
Fig. 4, are releasing magnets operated either by the transmitter T or by the
apparatus connected to the adjustable automatic conversation time limit.
S and S S, Fig. 4, are switches controlled by electro-magnets M³, M*, M' and M®.
S and S S2, Fig. 8 are substantial duplicates of the switches S and S S shown
in Fig. 4.
K, K, K, K, K, K, Figures 3, 4, 5, 7, and 8 are ratchet segments adjustably
secured to the rotary parts C1, C2, C3, C4, and C³, the size and number of the
ratchet teeth being dependent upon the proportionate times in which it is desired
to rotate the discs or cylinders to which they are attached.
W³, W³, W3, W³, are weights carried by levers pivoted to the frame of the
apparatus, their inner or free ends bearing under or beneath the curved portions
of the sectors K so that as the discs are rotated the weights W³ are lifted and
when said discs are released, these weights acting through levers will cause the
discs and sectors to assume their normal positions. In place of these weighted
levers I may use weights W2 and cords passing over pulleys like those shown
in connection with the ratchet wheel of the general time limit apparatus
in Fig. 2.
Referring now to Figure 10 which is an enlarged view illustrating different
positions of the circuit controllers carried by the rotary discs or cylinders C¹, C²
Cand C, is a strip of conducting metal secured at one end to one of the
conductors running to a releasing electro-magnet, in this instance shown as the
conductor 11, running to the releasing magnet d', Fig. 2, and to is a corresponding
conducting plate secured to the edge of the disc C', this plate being in turn
connected to the other end of the conductor 11. is an elastic or yielding
metallic plate carried also by the disc C¹ but insulated from it and the plate to.
The upper or straight edge of this yielding metallic plate lies snugly against the
end of the disc C', and the lower or V-shaped edge is curved outward from the
end of said disc and so that it is out of electrical contact with the fixed inner

page_text: plate, the arrangement being such that as the disc C¹ rotates in the direction of
the arrow in the first position the free end of the metallic plate t rides up over
the outwardly curved end of the plate 2 so that there will be no metallic contact
between the contacting plate t and the fixed plate t carried by the disc C' until it
leaves the upper curved or angular surface of the insulated plate and assumes
the position shown in the central figure, while on rotating the disc C' in the
reverse direction as shown in the right hand of the figure, the plates t* and to will
be in metallic contact as the former passes under the insulated plate 2 and
maintains contact between the plates t and to until the disc assumes its original
position, and passes out from under the end of the yielding plate as said disc
rotates in the direction of the arrow shown in the right hand portion of Fig. 10.
The action of these corresponding parts in Figs. 3, 4. 7 and 8 in connection with
the discs C', C2, C, C and C³ is the same, and the releasing electro-magnets d* d®,
ds, d3 and d are adapted to release said discs at the proper intervals of time.
I will now describe the mode of operation of the entire apparatus giving first a
description of the method of connecting up two subscribers where the number of
the subscribers' wires so connected lies between 1 and 9, and then describe the
method of connecting up two subscribers where the number of wires is over 9,
thus illustrating in the second instance how, with a limited number of wires
connected to each numerical receiver or two or more sets of such receivers I may
make connections between a large number of outlying subscribers' wires.
"
Suppose in the first instance it is desired to connect the subscriber on wire No. 1
and whose signalling and telephone instruments are shown in Fig. 1 with another
subscriber whose instruments are located on say wire No. 9. The several parts of
the apparatus at the outset are in the position shown in the drawings
of Figs. 1 to 8 inclusive and in full lines in Figures 12 and 13. The operator on
wire No. 1 turns the switch Sw into contact with that contact plate o lettered "0"
and then rotates the transmitter T through the agency of handle H one complete
revolution, thereby sending to line in the direction of the tailless arrows a single
impulse from battery BA by wire 1, switch lever (Fig. 2) wire 2, weighted switch
lever 1², wire 2, relay R, wire 2, relay R₁ earth E³, thus actuating these two
relays R and R¹. The relay R being energized causes its armature to close the
circuit of battery B through the circuit 4-4 and magnet (Fig. 5) thereby
causing the armature lever 1 and propelling pawl to act upon the ratchet
-sector K and rotate the " general circuit breaker C a fractional part of a
revolution interrupting the circuit, thus disconnecting all of the local branch lines
in the central station connecting the numerical receiver between the metallic
strips e and the series of contact springs s³ more clearly shown in Figs. 11 and 13.
At the same instant the relay R¹ which was energized as already described causes
the armature lever 12 to be drawn down so that the hook lever h² near its right
hand end catches the free end of the weighted switch lever 12. The cord c attached
to the other end of the armature lever and to a detent hook is simultaneously
drawn down over the pulley b, thereby drawing the hook h out of the path of a
catch on the face of the isolator cylinder I, there being a separate relay R' and
corresponding circuit and mechanical connections for each of the incoming
subscribers' lines 1 to 9 inclusive as shown in Figs. 9 and 12, the arrangement being
such that the operator signalling will draw his particular detent hook out of
the path of its catch, while the remaining detent hooks h will remain in the paths
of their catches.
At the same instant that the armaturer is drawn down by the relay R¹ a local
circuit 3 will be closed from the battery B' to the local electro-magnet d' imparting
to its armature land a detent hook a forward motion, thereby rotating the
isolator cylinder I a fractional part of a revolution and allowing a detent pawl p
to fall behind a stop on a disc attached to the shaft of the isolator cylinder.
This forward motion of the isolator cylinder causes all of the switch levers
(see Figs. 2 and 9) to be tilted forward under the influence of their hooks except
that one which has just been described as having been disconnected from the

page_text: isolator cylinder by the cord c. It will thus be seen that the circuit is interrupted
between all of the incoming subscribers' wires at the switch and the contact
points by this action of all of the switch levers 7 except the one last referred to,
so that no circuit can now be closed for incoming signals from other outlying
subscribers' instruments.
The
It is to be noted also that the clock or other time mechanism illustrated in Fig. 6
is supposed to be running continuously, thus constantly making and breaking the
circuit of the battery B A' between the yielding contact springs 9 9 and through
the circuits 12, 7, 14, 17, 22 and 24 and apparatus connected therewith when any
of said circuits are closed at other points as will be described later on.
preliminary impulse sent in by the transmitter T through contact plate "O"
switch S and circuit No. 1 as just described, has thus disconnected all of the
outlying subscribers' lines, save the one who has just signalled. As soon therefore
as the relay R¹ (Fig. 2) was demagnetized, its armaturer and hook lever h
shifted the circuit from the lower contact point at its left hand end to a second
contact point' just above, and a new No. 1 circuit was established by wire 1,
left hand switch L, wire 1, right hand magnet M2 of the right hand switch L
thence by wire 1 through back contact stop of the armature lever of relay R³ and
finally through relay R² to earth at E', both of said relays being found in Fig. 3
of the drawing. The electro-magnets R, R³, &c., which control the movements of
the numerical receivers and the switching magnets S S2 &c., Fig. 8, which
control the circuits in connection therewith, should be somewhat more sluggish
than the relays R and R', Fig. 2, in order that the preliminary impulse sent in
from any outlying station may not effect such of those magnets as may be in
circuit before the branch circuits are all interrupted at the "general circuit
breaker." Or the same may be effected by utilizing a signalling battery BA, Fig. 1,
at each subscriber's station of considerably less electro-motive force than the
battery B' A', Fig. 3, which controls the aforesaid electro-magnets.
The operator at station I now places the switch Sw in contact with the
plate No. 9. Supposing he desires to connect his wire with some operator on
wire No. 9, he then gives to the transmitter T one complete revolution as before,
thus sending ten impulses over the line in the same direction as before through the
lever (Fig. 2) upper contact a¹, wire 1, left hand switch L, wire 1, right hand
portion of magnet M2 which controls and turns the switch L thence to earth at E
at the bottom of Fig. 3 as already described. These ten impulses therefore actuate
the relay R2 and cause the battery B' A' at the bottom of Fig. 3 to send ten
successive impulses forward from earth E by armature of relay R2 and front contact
stop by wire 1 through the left hand switch S (Fig. 4) thence through wire 16 and
right hand magnet M which controls the two point switch S S (Fig. 4) thence by
wire 16 through electro-magnet K to earth at E³.
These ten impulses therefore impart to the numerical receiver No. 1 in Figure 5,
ten forward steps through the agency of the hook and retaining pawl k³ thereby
placing the conducting arm D of this receiver ultimately in contact with the right
hand plate 9 and hence with the circuit running to the subscriber desired as
clearly illustrated in dotted lines in Fig. 13.
Returning now to the right hand switch L at the top of Fig. 2, it will be seen
that by the act of shifting the lower end of its switch arm to the left a clock
circuit is established from the battery B2 A2 (Fig. 6) by way of the conductors 7-7
which circuit includes the actuating electromagnet d³ at the bottom of Fig. 2 so
that as the pendulum vibrates the general-time-limit apparatus E is set in motion
through the operation of the armature lever and propelling pawl h³. This
mechanism continues to advance step by step for a period of say twenty seconds or
twenty beats of the clock pendulum and during the first fifteen seconds of this
forward motion, the contact plate e of the general-time-limit apparatus is brought
under the two conducting springs ss, while the holding pawl k retains the apparatus
as it is advanced step by step and the restoring weight and cord W³ are drawn up
over the pulley n. When the contact plate e passes beneath the conducting

page_text: springs sa new clock circuit 12 is established through the contact points 99 and
battery B2 A2, said circuit 12 including an actuating electromagnet d³ for the
magneto signalling controlling instrument represented by the letter C1 (Fig. 3) so
that the ratchet sector K through the agency of the propelling pawl h, armature
lever and retaining hook k' is caused to advance step by step as the clock closes
the circuit at 99 in Fig. 6. During the first of the forward steps of the tooth
sector K and hence of the magneto signalling-controlling apparatus C¹, the
conducting plate e¹ carried thereby is brought under the two conducting
springs and an additional circuit is thereby closed through the conductor 13-13
from the battery B³ which circuit includes a releasing magnet do for the general
circuit-breaker shown at the bottom of Fig. 5, thereby performing two functions at
the same time: Namely, first releasing the general-circuit-breaking cylinder C³
through the agency of the armature lever 1, releasing cord e³, propelling pawl *
and detent pawl and allowing this cylinder to assume its normal position or that
now shown in Figs. 5, 11 and 13, thereby again restoring all of the subscribers'
circuits into through connection with the contact plates e³ and the numerical
receiver circuits, as clearly shown in Figures 5, 12 and 13.
It will be noted at this time that although the general circuit has been
re-established for all of the local branch circuits at the general circuit-breaker as
shown in Figs. 5, 11 and 13, all of the subscribers' circuits except the signalling
circuit are now broken at their points of juncture with the switch levers / by virtue
of the previous rotation of the isolator cylinder I so that there is only one path
for an incoming current.
The circuit 13 which includes the battery B³, contact springs and the
releasing magnet includes also a relay R³ located near the bottom of Fig. 3,
and it is therefore apparent that during the time that the conducting plate e¹ of
the magneto signalling controlling instrument C₁ remains under the contact
springs the armature of relay R³ will be held forward on its front contact stop.
The result therefore is that the constantly operating magneto generator H¹ is now
looped in circuit with both of the incoming subscribers' lines 1 and 9, and the
magneto bells M B at both stations continue to ring during the time that the contact
plate e' is under the springs s¹ s¹. As the instrument C¹ continues to rotate circuit
is made through conductor 9 and contact springs t3 and to and the battery circuit B³
near the centre of Fig. 3 is closed through circuit 9 including the releasing
magnet de, (Fig. 3), the right hand magnet of the left hand switch L at the top
of Fig. 2 and the left hand switch magnet M8 of the switch which controls the
adjustable conversation-time-limit apparatus in Fig. 7. Consequently the left hand
switch L at the top of Fig. 2 is turned with its lower point in contact with the
left hand contact point as shown in dotted lines in Fig. 12. The contact spring t
of the magneto controller C³, Fig. 3, has ridden over the insulated plate and
assumed the position shown in the central view of Fig. 10, thereby closing the
circuit of battery B' through wire 11 to the releasing magnet d thus releasing the
general time-limit apparatus E in Fig. 2, and allowing it to return to normal
position, it having first advanced far enough to close the circuit 10 through
contact springs t with a conducting plate o so as to energize the left hand magnet M²
of the right hand switch L at the top of the drawing and return it to normal
position, thereby rupturing the clock circuit 7-7. The general time-limit
apparatus for controlling the time of turning in the signal has been returned to
normal position and has shifted the switch of the right hand switch L at the top
of Fig. 2 to its normal position the magneto signalling controlling instrument has
been returned to normal position through the agency of the releasing magnet dⓇ
and the magneto generator cut out of circuit. The adjustable automatic time-limit
conversation apparatus has been set in motion through the agency of the circuit 9,
magnet M and switch Sw² (Fig. 7) a circuit having been established through
said switch, the conductor 24, operating magnet d and the clock circuit at
Fig. 6.
It will be noticed that the circuit 9 is provided with circuit closing devices at two

page_text: points, one on the apparatus C¹ in Fig. 3, and the other on the general time-limit
apparatus in Fig. 2, the arrangement being such that although electrical contact
is made between the plates 3 and as C advan es, the circuit will not be closed
between the plate 2 and the rotary plate carried by the general time-limit apparatus
until the latter has been released and returned to normal position, thereby allowing
the general time-limit apparatus to be released first and to afterwards release the
instrument C¹ and to perform the other functions already described.
When the relay R2 (Fig. 3) closed the circuit from battery B' A' through
line 1, the left hand switch S of Fig. 4 and the right hand magnet M, wire 16 and
magnet R (Fig. 5) the first impulse sent over the line caused the two point
switch S S to reverse its position and to close the clock circuit 17, thereby starting
the numerical separator C' almost simultaneously with the general time-limit
apparatus (Fig. 2). As the numerical separator advances under the action of the
apparatus 15 and hook lever h' it brings the contact plate e² under the contact
springs thereby closing a local battery circuit 15 from battery B* through the
left hand magnet M³ of the double switch S S restoring the switch to its normal
position and also through the left hand magnet M³ of the switch S shifting said
switch into the reverse position and hence directly in circuit with the arm D of the
numerical receiver in Fig. 5 so that the magneto call currents from the magneto
generator H' were caused to take the path through the conductor I joining the
two circuits thus connected together during the time that the armature of relay R³
was held forward on its front contact stop, while the contact plate e¹ of the
magneto signalling controlling instrument was passing under the springs s¹ sl.
The uninterrupted circuit therefore between the two lines 1 and 9 is as follows:
Passing from the earth at station I in the direction of the tailless arrows
through the wire 2 (Fig. 2) lever 1, wire 2, lever 12, upper contact upon which
lever is held by hook 2, wire 1, switch L and left hand contact point upon which
it is now resting, wire through ringing off magnet S' in Fig. 4, wire 6, wire 1
directly to the numerical receiver through the arm D to the wire 9 and thence
through the contact springs s³ ³, metallic plate e on the general circuit-breaker
directly to the outlying subscriber, see also Figs. 12 and 13. As the numerical
separator advances through its complete phase the local circuit of battery B³ seen
at the bottom of Fig. 4 is closed through the electro-magnet ds and conductors
running to the contact plates 4 and 5, the operation being the same as already
described in connection with like parts illustrated in Fig. 10, the releasing
armature lever 17 causing the hook lever and detent hook to allow the
sector K and disc C2 to return to normal position. Just before the magneto
signalling controlling instrument was returned to its normal position by the
releasing electro-magnet de in circuit 9 and at the instant that the general time-
limit apparatus returned to its normal position and closed the circuit 9-9 the
switch Sw of the adjustable automatic conversation time-limit apparatus (Fig. 7)
was turned into its upper position under the influence of magnet M8 which is also
in circuit 9 so that after the magneto signal has been sent in and the two subscribers
connected together as already described, this adjustable automatic conversation
time-limit apparatus is now put in operation by the agency of the clock circuit 24
which runs to the clock and energizes the propelling electro-magnet d¹ thereby
causing the sector K of this apparatus to advance step by step for a definite
number of seconds or minutes or such time as may be allowed for conversation, the
apparatus shown in Fig. 7 of the drawings merely indicating the application of this
time-limit principle. As the two subscribers converse therefore the apparatus C³
advances and ultimately the contact plate et rides under the conducting springs &* &*
closing the circuit of the battery B8 through the conductors 18 to the releasing
electro-magnet S near the centre of Fig. 4 of the drawing, thereby lifting the
armature lever v and allowing the armature lever to be withdrawn from the
notch on the under side thus locking the armature vin its upper position in contact
with a conducting contact connected to the clock circuit 14. On the first closure
of the clock circuit therefore through the circuit 14 the left hand switch S of
B

page_text: Fig. 4 is shifted by magnet M₁ to its first or normal position and simultaneously
the automatic releasing mechanism at the bottom of Fig. 7 is stepped forward
under the influence of the electro-magnet d' until the contact plate e is carried
under the contact springs thus closing the battery circuit B through the
conductor 8 and right hand electro-magnet M' shifting the conversation time-limit
switch S back to its normal position, simultaneously energizing the releasing
electro-magnet 8 in the same circuit, thereby releasing the adjustable automatic
conversation time-limit mechanism and allowing it to rotate back to its normal
position.
At the same instant the releasing magnet d¹¹ in the same circuit No. 8 of the
numerical receiver in Fig. 5 is actuated, allowing the weight W2 to return the
conducting arın D of the numerical receiver to its first or normal position.
The electro-magnet of the ringing-off apparatus F, Fig. 4 is also caused to
draw the armature v¹ into its forward position and release the armature v. The
electromagnet M' of the upper left hand switch L in Fig. 2 being in the same
circuit 8 causes the switch to be turned to its first or normal position and the
releasing magnet d* which is also in circuit No. 8 in Figure 2 lifts the pawl p and
allows the isolator cylinder to be restored to its normal position. The releasing
magnet d which is also in circuit No. 8 in Fig. 2 is caused to release the armature
lever hook from the end of the weighted lever 12, thereby allowing said lever to
assume its original or normal position.
Last of all the automatic release itself at the lower part of Fig. 7 of the
drawings is effected through the agency of a local circuit and electro-magnet d¹³
in the same manner as the apparatus (2 at the bottom of Figure 4 was released
as heretofore described.
It is now apparent that the several parts of the apparatus put in operation from
the transmitter T at the station of the signalling subscriber have served their
various functions in sequence and that the adjustable automatic conversation time-
limit apparatus having limited the time of the conversation the entire mechanism
at the central station has again assumed its normal condition and that the isolating
cylinder I has again connected all of the outlying subscribers' lines with the
signalling receiving mechanism for said lines at the central station. Any other
operator may now turn in his signal and automatically connect his particular line
with any other line in the system, the operation being identically the same as has
heretofore been described.
Should any subscriber attempt to signal during the time that the apparatus is in
use by reason of a signal previously sent in, it is apparent that he will receive no
signal on his own magneto-bell, his line being like that of all subscribers, save the
one who has previously signalled, cut out at the isolator cylinder, Figure 2. He
must wait therefore until he obtains a signal on his own bell on turning in a signal
before he is aware of the fact that his proper circuit connections have been made.
The absence of such a return signal is indicative to him of the fact that the
system is in use and that he must wait until the proper circuit connections are again
automatically made at the central station.
"
It is to be understood, however, that although all of the subscribers' outlying
lines, save the one who is signalling, have been cut out of circuit at the isolating
cylinder (Figure 2) for transmitting signals, all of the said lines are still connected
with the numerical receivers for receiving signals at the points "0" to "9
inclusive over which the conducting arm D passes and also through the contact
springs and conducting plates es, the latter attached to the general circuit-
breaking cylinder C³ (see Figures 5 and 13).
1 will now describe how I am enabled to unite two or more subscribers' instru-
ments located in independent outlying subscribers' lines where the number of such
outlying lines is greater than 9.
My system of uniting any two of an indefinite number of subscribers' lines is
based upon what I term the "units," "tens," and "hundreds" principle, and I
connect the first nine subscribers 'lines running into the central station with a

page_text: numerical receiver which is connected to ten local or branch wires, each one of
these local or branch wires being connected in turn to one of a series of secondary
numerical receivers having in turn ten similar connections, each one of which runs
to one of a series of third numerical receivers and so on indefinitely. Automatic
switching apparatus is also included in circuit between the several numerical
receivers whereby the circuit connections are shifted so that the main battery B'A'
at the bottom of Figure 3 is caused to automatically advance the numerical receiver
and its conducting arm D to the desired point through the agency of the relay R'
(Figure 3) and the electro-magnet R (Figure 5) and then shift the circuit con-
nections from this electro-magnet R' to the electro-magnet of the next succeeding
numerical receiver and so on in sequence, the main battery B¹ A' being utilized to
drive these numerical receivers in succession.
In other words, the first numerical receiver makes connection directly for nine
subscribers' wires and these connections are in turn connected to one of a series of
secondary numerical receivers, each of which has provision for connections to one
of a series of numerical receivers of the third order, the number of possible con-
nections therefore being in geometrical progression and the circuit connections
through the primary numerical receiver being adapted to connect up the individual
subscribers' connections through additional numerical receivers in any desired order.
Figure 14 of the drawings shows a system approximating a thousand subscribers'
lines with circuit connections at the central or switching station through the
isolator, the general circuit breaker, and three series of numerical receivers. The
apparatus for operating the isolator, the general circuit breaker, and the numerical
receivers is not shown in this figure of the drawing, nor are all of the one thousand
subscribers' lines shown, the diagram being in the nature of a skeleton which
illustrates only a sufficient number of such lines to give a correct understanding of
the switching circuits through the exchange.
It will be understood that all of the subscribers' lines come into the office at the
top of the drawing and divide each into two branches, one of which is connected
to the isolator and the other to the general circuit breaker in the manner already
described and that all of these lines are broken at the isolator when the preliminary
signal is sent in except that line over which the impulse is transmitted, and also
that the other branches are simultaneously broken at the general circuit breaker
until the proper connections are automatically made through the various series of
numerical receivers and circuit connections, after which it (the general circuit
breaker) is restored to its normal position, the isolator remaining in its abnormal
position until the conversation is through, so that all of the subscribers' lines are
disconnected at the isolator during the conversation except that of the subscriber who
signalled and that it is automatically released by the act of ringing off, after which
any other subscriber may in like manner obtain control of the isolator and the
switching apparatus and send his signal through numerical receiver No. 1 in such
manner as to make the desired connection to the subscriber called.
For a higher or greater number of subscribers' lines, say approximating ten-
thousand lines, a fourth series of numerical receivers would be necessary, such
fourth series of numerical receivers having a similar set of connections with the
third series of such receivers, as do the latter with the second series of numerical
receivers as will be clearly appreciable on inspection of the drawings.
It will thus be apparent that there is no limit to the number of subscribers' wires
which may be connected, it being readily appreciable that by this utilization of
numerical receivers in which the circuit connections increase in geometrical ratio,
I can, with a reasonably small number of such receivers connect a very large
number of subscribers' lines.
Suppose now it is desired to connect subscribers' circuit No. 1 with circuit No. 18
Under this condition of affairs the second subscribers' line being in the second
order of numerals it will be necessary to bring into play numerical receiver No. 2
The
one of the second series of numerical receivers, see Figures 8, 13 and 14.
. operator at station No. 1 goes through the same operations as before described in

page_text: transmitting the preliminary signal and for the purpose of connecting up his circuit
with that one of the circuits connected with numerical receiver No. 1 which is
to continue the connections through to numerical receiver No. 2 of the second
series of numerical receivers. He therefore after the preliminary signal has been
sent in, places the switch S on the contact plate numbered I and rotates the
transmitter T one revolution as before. This advances the arm D of the numerical
receiver No. 1 two steps and places it in contact with the contact plate I shown in
dotted lines in Figure 13.
It will be understood of course that in advancing the arm D to the point 1, the
numerical separator, Figure 4 of the drawings, has operated as before described,
and transferred the circuit through the agency of the switch S S so that the
circuit connections on line No. 1 are direct to the arm D and contact plate I of the
numerical receiver No. 1. Electro-magnet R of numerical receiver No. 1,
Figures 5 and 13 by the operation of the numerical separator has also been
disconnected from the circuit running to the main battery B₁ A' at the bottom of
Figure 3 and electro-magnet R³ of numerical receiver No. 2 (Figures 8 and 13)
has been connected in circuit through conductor No. 19 with that battery.
The
The operator now turns the switch S▾ upon contact No. 8 and gives to the
transmitter a second complete revolution, thereby sending to line nine successive
impulses through B' A. These nine impulses take the following course.
relay R² being energized in the manner already described by the currents from
battery BA (Figure 1) cause the battery B₁ A¹ to repeat the nine impulses
through conductor No. 1. through the switch S (Figure 4) and lower right hand
contact point thereof, it having been tilted in this direction by the action of
battery B and the numerical separator, thence by wire 1 directly to the numerical
receiver No. 1, thence by wire No. 19 to switch S¹ (Figure 8) thence by the right
hand electro-magnet of the two point switch S2 S3 and thence through electro-
magnet R to earth, see also the same circuits in Figures 12 and 13. These nine
impulses therefore carry the arm D' of the numerical receiver No. 2. forward to
the contact plate No. 18 shown in dotted lines, Figure 13, in direct connection with
the metallic plate e³ of the general circuit-breaker (Figure 5), the outlying line
being No. 18.
The first impulse which came over wire 19 from battery B¹ A' as just described,
shifted the two point switch S2 S2 (Figures 8 and 13) in the reverse direction and
brought the contacting arms thereof in electrical connection with the contacts at
the lower ends, thus closing in the one instance the clock circuit 22 running to the
clock and to the numerical separator at the bottom of the drawing, thereby causing
the magnet d to be energized by the clock battery B2 A2 and to step forward the
tooth sector K step by step until the contact plate e rests under the conducting
springs²² thereby closing in the second instance the circuit of battery B* through
wire No. 20, left hand magnet of switch S' and left hand magnet of switch S S²
which turned both of the switches to their left hand positions.
Wire No. 19 is now in direct connection with the second numerical receiver through
wire No. 23 and subscribers' circuits Nos. 1 and 18 are connected, the magneto
signal having been sent over both circuits through the agency of the magneto
signalling controlling instrument and the apparatus in the same manner as was
described in connection with the first part of the operation of the apparatus.
In other words all of that portion of the apparatus embraced in Figures 2, 3, 4,
5, 6, and 7 operated as was before described to perform the several functions
attributable to such apparatus, the two circuits 1 and 18 being thus connected,
conversation proceeds as before until the adjustable automatic conversation time-
limit apparatus is advanced to its limit and the releasing apparatus actuated as
before. The electro-magnet d" being in the releasing circuit No. 8 as is also the
right hand switch magnet of the switch S' at the top of Figure 8 of the drawings,
it will be understood that when the automatic conversation time-limit apparatus
operates, the numerical receiver No. 2 will be released, the switch S' (Figures 8.
and 13) will be restored to its normal position and the releasing apparatus connected

page_text: with the receiver No. 2 will be released by virtue of the local circuit connections
with battery B' and electro-magnet d³ when all of the apparatus will return to
normal position as before. Although the restoring of all of the apparatus to normal
condition is made dependent as heretofore described upon the automatic conversation
time-limit apparatus illustrated in Figure 7 and the circuit connections through
battery B and conductor No. 8 running through Figures 2. 3. 4. 5. 6. 7 and 8 of
the drawings this same function may be performed by either one of the subscribers
at the end of their conversation without waiting for the termination of the time, by
simply placing the switch Sw in circuit with the "0" contact and rotating the
transmitter T one turn. This will cause the main battery B A at the transmitting
station to energize the releasing electro-magnet S, Figures 4 and 12 of the
drawings, and return all of the apparatus to normal position and will also release
the automatic releaser for the reason that the clock circuit 14 will be closed at the
back stop of the armature lever vso that the first impulse which passes over the
circuit 14 will place the contact plate e under the springs thereby closing
the general releasing circuit 8 which operates all of the releasing devices.
In Figures 12 and 13 I have given a diagrammatic view of a complete system of
nineteen subscribers' lines earthed at outlying points E, E, and all entering the
central station, each subscriber's line having two branches, one of which runs to
the isolator I, Figure 12, and the other to the general circuit breaker, Figure 13,
two numerical receivers being shown as are also the necessary switching magnets
for controlling the circuits in relation thereto, the circuits and circuit connections
therefor being as shown in Figures 2 to 8 inclusive. It will, of course, be under-
stood that all other incoming lines of the higher orders would in like manner enter
the central station and branch in the same manner to the isolator cylinder and the
general circuit breaker and that the higher orders of branch connections in the
station would run in sequence from the contact plates 1, 2, 3, 4, &c., 10, 11, 12,
13, &c., to the successive sets of numerical receivers as illustrated in Figure 13,
the contact plates of each numerical receiver acting as radial points of distribution,
each to an individual numerical receiver of higher order and the switching
mechanism, controlling magnets and general circuit connections being a
duplication of the corresponding parts shown in connection with numerical receivers
No. and No. 2.
mere
To further exemplify this decimal method of connecting up subscribers' lines,
suppose that operator No. 1 desires to connect his line 999, see Figure 14.
Pursuing the method of operation already indicated he advances the arm D of
numerical receiver No. 1 to the last contact on the extreme right; the numerical
separator has operated in the meantime and the necessary connections have been
made through branch wire No. 13¹ for causing the numerical receiver on the
extreme right in the second series to advance the arm D' to the position indicated
so that it is in connection with line No. 99 and branch line No. 27¹ running to the
numerical receiver of the third series on the extreme right. The next numerical
separator has operated and made the necessary connections so that the arm D³ of
the last numerical receiver of the third series is stepped forward until it is in
contact with line No. 999.
Under this condition of affairs line No. 1 is in circuit under the isolator, circuit
wire, wire 1, arm D of numerical receiver No. 1, branch circuit 131 running to
arm D of numerical receiver No. 2, branch circuit 27' running to arm D³ of
numerical receiver No. 3, thence directly through the general circuit breaker to
line No. 999 and out to the subscriber.
In operating the apparatus should the subscriber on line No. 999 desire to
connect himself with subscriber on line No. 1, it would be necessary for him to send
in the same signal which line No. 1 sent in in connecting his, No. 1's, line with
No. 999; that is to say, the numerical order of sending in the signal is always
from the lower numbers to the higher in sequence, and this for the reason that the
numerical receivers operate in sequence in the manner already described, from the
lower order of decimals to the higher order thereof.

page_text: It will be observed that when line No. 1 is connected to line No. 999 there is
also connection to line No. 9 and line No. 99. In other words in connecting up
any line between line No. 1 and line No. 999 there will always be at least four
subscribers connected together, in so far as conversation connections are concerned,
and that for any line between 1 and 99 there will be three lines so connected.
None of the outlying subscribers, however, can interfere with the persons holding
conversation, other than by talking into their transmitters, as the signalling
apparatus proper is put wholly out of the control of the subscribers themselves
after one of them has once sent in his preliminary signal until the apparatus at the
central station has restored the entire mechanism to its normal condition, so that
although three or more subscribers may be called up by the same signal it will be
an easy matter for the one who signalled to indicate the fact as to which subscriber
he desires.
The transmitter T it will be observed is of a very simple nature and its operation
for the purpose of uniting any subscriber's line with that of any other outlying line
through the agency of the automatic apparatus at the central or switching station
is effected by simply turning the handle H one complete revolution after placing
the switch S upon that one of the contact plates O which corresponds to the line
wanted, if said line is among those whose number is less than ten and repeating the
operation with one rotation for each line, the number of such operations being
dependent upon the decimal relations of the lines to be connected. Although 1
prefer to use the special form of transmitter hereinbefore described and hereinafter
claimed, I do not limit myself to the use of this particular form of transmitter as it
is obvious that by the proper manipulation of an ordinary make and break key, I
might effect the desired order or sequence of current impulses for operating the
mechanism at the central station.
Nor do I limit myself to the use of all of the apparatus hereinbefore described
in connection with an automatic telephone exchange system as many of the features
are clearly applicable to a central or switching station in which the connections are
made by hand. In this connection it is obvious that the numerical receivers or
switches might be operated by hand, as I believe it is broadly new with me to
provide a system of cross conductors in a central station in which a limited number
of such conductors is utilized with a series of numerical receivers or switches which
increase in geometrical order and in which the connections are made in the first
instance through one conductor and in the succeeding instances through
succeeding radiating or increasing series of like conductors with intermediate
switching apparatus.
I believe it is also broadly new with me to provide automatic conversation time-
limit apparatus in connection with two or more subscribers' lines and so related
thereto that the subscribers will be limited to a pre-determined time for their
conversation for each call and that their lines will be automatically disconnected at
the end of that time and the circuit connections at the central or switching station
restored to normal condition.
My invention contemplates also the use of such apparatus in a generic sense
whether with automatic or hand actuated switching devices.
My invention embraces also the application of several novel principles, notably
the method of uniting any two of a series of subscribers' lines by the transmission
of simple current impulses, and the separation of these impulses into successive sets
or orders, whereby the lines are automatically connected up in the order of tens,
hundreds, thousands, &c.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I claim is:―
1. An automatic telephone exchange system having a series of subscribers' lines
all connected to a circuit interrupter at one point; branches or forks running to a
second circuit interrupter connected to all of the lines; electro-magnetic apparatus
for controlling both circuit interrupters and switching apparatus and electrical

page_text: connections whereby the circuit is interrupted for all of the lines at one point, and
for all of the lines save the signalling line at another, in combination with trans-
mitters located in the subscribers' lines for actuating the switching apparatus.
2. A series of telephone or analogous electrical conductors leading to a switching
apparatus located at a central or exchange station, said switching apparatus
consisting of a numerical receiver switch controlled by an electro-magnet adapted
to be energized by electrical impulses passing over any one of the incoming lines, in
combination with one or more series of similar numerical receivers provided with
circuit connections between themselves and the first numerical receiver, and
additional circuit connections with the remaining outlying lines and one or more
time controlled separating devices for switching the signalling impulses through the
several numerical receiver switches progressively.
3. A series of telephone or analogous electrical conductors leading to a central
or switching station, a numerical receiver switch, electro-magnetic means for
connecting any one of the incoming lines to the numerical receiver switch electro-
magnet, a series of additional numerical receiver switches arranged in sets and
provided with circuit connections for connecting them to the first numerical receiver
switch, in combination with one or more time controlled separators for changing the
circuit from the numerical receiver switch to any of the additional numerical
receiver switches in any desired order.
4. A series of telephone or analogous electrical conductors running to a central
or exchange station, each line being provided with means for connecting it
operatively with a single switching device, in combination with one or more sets of
similar switching apparatus provided with means for connecting said apparatus to
the first switching apparatus, and additional mechanism in the nature of time
controlled apparatus provided with circuit connections whereby the switching is
effected through the desired switching apparatus during intervals of time between
the switching signals transmitted.
5. A series of telephone lines operatively connected with a common or general
circuit breaking device at a central or switching station; local branches in the
station running from each line to a second circuit breaking device and electro-
magnetic means in combination with circuit controlling apparatus located at the
station and in the outlying lines, whereby both circuit interrupters may be actuated
and restored.
6. A series of telephone lines each connected by two branch wires to two.
independent circuit breakers adapted to break the circuits of all of the lines save the
signalling line, in combination with electro-magnetic means for controlling the
movement of both circuit breakers.
7. A series of telephone lines running to a common or central switching station
and connected with a corresponding series of branch wires and a common circuit
controlling device; additional branch conductors running to a controlling relay, in
combination with a second circuit controlling relay and electro-magnetic switching
apparatus and circuit connections whereby the first set of branch wires is wholly
interrupted, the second set all interrupted except the one connected to the line over
which a call has been sent in and the first circuit controlling device restored so as
to connect all of the lines at the first point of interruption and only one at the
second.
8. A series of telephone lines leading into a central or switching station and to a
common circuit controlling relay R', a series of branch lines equal in number to
the incoming lines and all connected through a switch or circuit controlling device
under control of the aforesaid relay; circuit connections from said branches.
through a switch having electro-magnetic means for causing it to automatically
connect up the desired circuits, in combination with releasing and restoring devices.
for returning the common circuit controller and the switching apparatus to normal
position.
9. In an automatic telephone exchange a series of telephone lines having each
wo branches at the central station and provided with general circuit interrupters

page_text: at the exchange adapted to interrupt the circuits of all of the incoming lines excepting
that of the subscriber signalling at two points, in combination with means for
controlling their operation.
10. An automatic telephone exchange system in which all of the lines lead to two
general circuit interrupters adapted to break the circuit of said lines at two
independent points and to leave one line connected with the exchange in combina-
tion with automatic circuit switching apparatus which makes the necessary circuit
connections and again restores all of the lines to normal circuit connection at the
first point of connection but leaves them all interrupted at the second interrupter
save the line which conveyed the signal.
11. In a telephone exchange system a series of telephone lines leading into a
central exchange, each line having two local branches in the exchange, one of
which is connected to earth through an isolator or circuit breaking device provided
with means for interrupting all of the circuits save that of the subscriber signalling,
while the other branch is connected to contacting devices carried by a general circuit
breaker provided with means for interrupting the circuits of all of the lines during
the time a signal is being turned in and afterwards restoring circuit at the points.
12. A series of telephone lines leading into an exchange, each line having two
branches at the exchange one of which leads to a general circuit breaker for all of
the lines and the other to and through a relay or electro-magnet R¹ to earth, while
the first branch is left normally open.
13. In an automatic telephone exchange system one or more numerical separators or
rotary switching devices having electrical circuit connections with a time mechanism;
one
or more two point switches and controlling electro-magnets therefor with
circuit connections between the numercial separators the time mechanism and the
controlling electro-magnets whereby the time mechanism circuits are automatically
brought into action, the switches operated and the time mechanism circuits again
discontinued.
14. In an automatic telephone exchange system a series of subscribers' lines all
normally connected through a general circuit breaker through individual switches
having electrical connections and electro-magnetic controlling devices whereby
only one of a series of lines may be left in circuit through the circuit breaker,
while the others remain disconnected, in combination with an electro-magnetic
restoring device for restoring the general circuit breaker to its normal position.
15. In an automatic telephone exchange system a series of subscribers' lines all
normally connected through a general circuit breaker and a controlling electro-
magnet therefor each line having an independent switch operatively connected
to the circuit breaker, in combination with controlling electro-magnets for said
switches and circuit connections whereby any line may maintain continuous circuit
connection through the circuit breaker while the others are disconnected therefrom.
16. In an automatic telephone exchange system a series of subscribers' lines
normally connected through a general circuit breaker in combination with circuit
switching apparatus for automatically connecting any two lines, and electrical and
mechanical connections whereby any line is left connected through the circuit
breaker the switching apparatus and any other outlying line while the circuits
remain interrupted for all other lines at their points of connection with said general
circuit breaker.
17. A telephone exchange system consisting of a series of telephone lines
radiating from a central station; a series of switching devices for connecting any
two lines together, said switching devices consisting of a single short branch line
and one or more series of like short branch lines located in the central station and
means for connecting said short branch lines together and to the telephone lines in
any desired order, the arrangement being such that the connection is always made
through one single short branch line for all orders of connection and through the
other short branch lines in sequence for the higher orders of connection.
18. In a telephone exchange system a branch switching line and one or more
series of additional branch switching lines all located in the central station; means

page_text: for connecting the branch switching line to all outlying telephone lines and
additional means for connecting said branch switching line to the additional branch
switching lines which in turn are provided with means for connecting them to any
of the outlying telephone lines whereby all signals and communications between
any two telephone lines are had over the first short branch line and the desired one
of the additional series of branch lines.
19. A telephone exchange system having a series of outlying telephone lines
operatively connected through switching mechanism with a branch switching line,
one or more series of connecting lines arranged in decimal order and provided
with means for connecting them with the branch switching line and certain of the
outlying telephone lines or with the branch switching line and with each other and
additional outlying telephone lines.
20. In a telephone exchange system a series of telephone lines provided with
means for connecting them to a single short branch line; a series of radiating
short branch lines provided with means for connecting them to the first branch line
and a third series of short branch lines provided with means for connecting them
to a second series of short lines each short branch line of each series being connected
in turn to some one of the outlying telephone lines.
21. In an automatic telephone exchange system a numerical receiver or switch
having circuit connections of decimal order, with a second series of like receivers,
or switches and circuit controlling devices and connections whereby all outlying
lines of all orders of numerical value are connected through the first switch and
through the other series of switches in the order of their decimal relation.
22. In a telephone exchange system a single branch conductor united to a switch
adapted to contact with a series of conducting contacts in combination with a
series of like switches provided with means for connecting any one of them through
any one of the aforesaid contacts with outlying subscribers' lines and means for
connecting them through the switches; the arrangement being such that the
connections for the lower numbers are through the first switch only, and for the
higher numbers through the first switch and the successive series as described.
23. A telephone system provided with signal transmitters on each outlying line;
a central exchange including a series of numerical receivers or switching devices,
the first of which has a single branch connection and means for connecting it to
any subscriber's line, while the others of like construction are arranged in
increasing series so that all circuit connections pass through the first single
branch wire.
24. An automatic telephonic exchange system having a numerical receiver or
switch normally out of circuit with all outlying lines and provided with connections
for connecting any two lines through it in combination with circuit interrupting
mechanism for disconnecting all of the lines but the signalling line and thep
restoring connections through the remainder of the lines at a point near the
numerical receiver or switch and finally advancing the latter until the proper
connection is made.
25. A telephone exchange system having a single switch, the stationary part of
which is connected to a short conducting switching line provided with means for
connecting it with any one of the entire series of subscribers' lines, the movable
part of said switch being adapted to be connected with stationary or fixed contacts
which in turn are connected to the fixed parts of similar switches, the movable
parts of which are adapted to contact with fixed contacts operatively connected
with individual subscriber's lines.
26. In an automatic telephone exchange system a series of subscribers' lines';
one or more numerical receivers or switching devices; a magnetic calling generator
and a time limit apparatus for limiting the time of connecting and calling a
subscriber, in combination with releasing mechanism for restoring the apparatus to
normal condition.
27. A series of telephone lines; a number of short branch lines for connecting
said telephone lines together in pairs, one of said short branch lines being provided

page_text: with means for connecting it to any one of the telephone lines, and additional
means for connecting it to any one of the remaining short branch lines, in com-
bination with means for connecting the second set of short branch lines each to an
outlying telephone line.
28. A telephone exchange system provided with a system of cross or connecting
conductors arranged in increasing decimal series whereby all orders of less than
ten are connected through a single conductor and all above ten through divided
or radiating branches connected to the first conductor and switches for making the
necessary connections.
29. A signalling transmitter for an automatic telephone system consisting of a
series of contact plates of varying length connected to a common conducting axis
and a corresponding series of fixed contact plates with their free ends resting on
the first named plates and the fixed end lying in the path of a switch in com-
bination with an electrical circuit and a time relay or separator and means whereby
when two or more series of impulses are transmitted to a central exchange each
series will be automatically directed over a path differing from that taken by the
preceding series.
30. A transmitter having a series of movable contacts and a corresponding series
of fixed contacts plates adapted to contact therewith at the free ends, their fixed
ends having contacts lying in the path of a single contact switch in combination
with a movable contact having an earthed circuit connection through call
mechanism.
31. A transmitter having means for transmitting one or more current impulses
at each revolution, and a switch adapted to vary the number of such impulses at
will, in combination with a circuit closing plate carried by said transmitter, and
connections therefor adapted to close a circuit through a magneto call bell or other
signalling device when said transmitter is in its normal position of rest.
32. A transmitter having means for transmitting one or more current impulses
at each revolution, a switch adapted to vary the number of such impulses at will,
a circuit closing plate carried by said transmitter adapted to close a circuit through
a magnetic call bell or other signalling device; together with such arrangement
of parts that when the transmitter is revolved, the magneto call bell or other
signalling device will be cut out of circuit.
33. In an automatic telephone exchange system, a series of subscribers' lines
provided each with one or more sets of telephonic apparatus and signalling or
circuit interrupting call apparatus; a time limit apparatus for limiting the time
of turning in a call and ringing alarms at any two stations; automatic switching
apparatus connected electrically with circuit controlling apparatus and automatic
releasing mechanism for restoring the lines to their normal condition after a given
time.
34. In an automatic telephone exchange system a series of numerical receivers
or switching devices; one for the tens, and a series of like apparatus for each
order of numerals in increasing ratio, in combination with one or more numerical
separating devices and electrical and mechanical connections whereby any two
lines may be automatically united in any desired order according to their numerical
relation, the first numerical receiver being connected on one side to a single short
line and on the other side through additional short lines to the second series of
numerical receivers which in turn are connected to outlying telephone lines.
35. In a telephone exchange system a series of telephone lines arranged in
Dumerical order of units, tens, hundreds, and thousands; a numerical receiver
switch of the first order connecting to units; a series of numerical receivers of
the second order connecting to tens and units; a series of numerical receivers of
the third order connecting to hundreds, tens and units, and a series of numerical
receivers of the fourth order connecting to thousands, hundreds, tens, and units;
in combination with one or more numerical separating devices and electrical circuit
connections for shifting the circuits in the desired order of tens, hundreds and
thousands and electrical and mechanical connections whereby a maximum number

page_text: of line connections in pairs is effected with a minimum number of wires
central station.
36. A telephone exchange system having a means for automatically connecting
together any two of a series of independent outlying telephone lines in combination
with a time mechanism provided with electrical and mechanical connections in the
nature of electro-magnetic switching apparatus whereby any two subscribers' lines
will be automatically disconnected after a pre-determined time and the lines restored
to normal condition.
37. A telephone exchange system having a magneto call generater located at the
central office; a magneto call bell located in each subscriber's line; switching
mechanism at the central station and transmitters at the subscribers' stations in
combination with an automatic conversation time limit apparatus and additional
mechanical and electrical connections whereby any subscriber may connect his line
automatically with that of any other subscriber, ring both bells, disconnect the
magneto generator, hold the desired conversation for a pre-arranged length of time
and the lines be restored to normal condition.
38. In an automatic telephone exchange system a numerical receiver or step-by-
step switch having a movable contact arm controlled by an electro-magnet adapted
for connection with any one of a series of incoming lines, in combination with
automatic switching mechanism controlled by a time controlled separating device
for switching the circuit from the controlling electro-magnet into said movable
contact arm.
39. A numerical receiver or circuit changing switch for changing the circuit
relations through subscribers' lines, said switch being connected to a conductor
and to a second normally open switch; means for connecting any calling
subscriber to the numerical receiver and for advancing it step by step and
additional means consisting of a time controlled separating device and circuit
connections whereby the numerical receiver is actuated, the propelling electro-
magnet cut out of circuit and the receiver then connected to the line of the
subscriber called.
40. In an automatic telephone exchange system one or more switching devices
controlled by electro-magnets; a series of subscribers' lines and circuit connections
therefrom to the switching apparatus; transmitters for causing the switches to
advance through their phases and the mechanism and releasing devices whereby
the switches are all restored to normal condition after a pre-determined length
of time.
41. In an automatic telephone exchange system a numerical receiver or circuit
changing switch of the first or units order; a series of numerical receivers of the
second or tens and units order; means for connecting a calling subscriber to the
numerical receiver of the first order and for advancing it step-by-step and additional
means consisting of time controlled separating devices and circuit connections for
then cutting out the propelling electro-magnet, changing the circuit to one of the
numerical receivers of the second order, advancing it step-by-step and finally cutting
its propelling electro-magnet out of circuit and connecting through said receivers
to the line of the subscriber called.
42. In an automatic telephone exchange system a series of subscribers' lines; a
time mechanism and a time limit apparatus for limiting the time of sending in
a signal; means for causing the time mechanism to actuate the time limit apparatus
for any pre-determined length of time on the reception of a signal at the exchange
from an outlying subscriber and additional means for restoring the apparatus to
normal condition at the expiration of the time limit.
43. In an automatic telephone exchange system one or more numerical receivers
or switching devices a general time limit apparatus; one or more numerical
separators for controlling the numerical receivers in sequence and automatic
releasing devices and circuit connections whereby the subscribers' lines are connected
in any desired order.
44. A circuit controlling device consisting of an insulated plate ³ overlying a

page_text: conducting plate to carried by a moving surface and having circuit connections with
an electro-magnetic releasing device which permits the moving surface to return to
its normal position after it has carried the circuit controller forward and closed the
circuit through the releasing device.
45. A circuit controlling device carried by a rotary or movable switch having
electro-magnetic means for advancing it step by step and separately connected
through a time controlled mechanism whereby the switch is released and restored
to normal condition after a pre-determined time.
46. A circuit controlling device carried by a rotary or movable switch having
electro-magnetic means for advancing the switch step by step and a releasing device
operatively connected to the controlling device provided with means whereby the
switch is restored to normal position after it has advanced to such a position as will
automatically close the circuit through the circuit controlling device and the
releasing device, and will also keep the releasing circuit closed until the switch has
returned to its normal position.
47. In an automatic telephone exchange system a series of subscribers' lines;
a series of electro-magnetic switching devices for uniting any two of said lines
together, all of the switches being normally disconnected from all subscribers' lines
and provided with circuit connections through one or more time controlled
numerical separating devices whereby the switching devices are actuated in
sequence and caused to connect the subscribers' lines therethrough in any desired
order.
48. In an automatic telephone exchange system a series of subscribers lines
provided each with telephonic instruments, a signalling generator and a circuit
breaking signal transmitter all connected to two general circuit interrupters through
branch circuits; a series of cross connecting circuits and a series of electro-
magnetic switching devices all normally disconnected from circuit but provided
with electro-magnetic means for operating them in sequence and connecting up any
two lines, in combination with automatic releasing mechanism connected to and
controlled by a time mechanism for limiting the time of any two lines are connected
together.
49. In a telephone exchange system a series of subscribers' lines; means for
automatically connecting any two subscribers' lines together in combination with a
releasing device and additional means consisting of a time controlled apparatus
adapted to be set for any pre-arranged time limit and having circuit connections
whereby such releasing device is automatically placed in the circuit of any two
connected wires for the purpose of automatically disconnecting them after the
expiration of any pre-determined time limit.
50. In a telephone exchange system having outlying subscribers' lines provided
with signalling mechanism; one cross connecting line located on the exchange and
adapted to be connected to any telephone line and one or more series of additional
cross connectors each of which is adapted to be connected to the first cross
connecting line in combination with time controlled separating devices for auto-
matically joining up in one circuit the cross connectors selected by the signalling
subscriber.
51. In a telephone exchange system having outlying subscribers' lines provided
with signalling mechanism; one cross connecting line located in the exchange
and adapted to be connected to any telephone line and one or more series of
additional cross connectors adapted to be connected to the first cross connecting
line, in combination with time controlled separating devices for automatically
joining up in one circuit the cross connectors selected by the signalling subscriber
and joining the line of the calling subscriber to that of the subscriber called.
52. An automatic telephone exchange station having means consisting of a time
controlled device and circuit connections for automatically limiting the length of
time during which any two subscribers may hold their lines in connection.
53. An automatic telephone exchange station having means consisting of a time
controlled device and circuit connections for automatically limiting the length of

page_text: time during which any two subscribers may hold their lines in connection and
additional means for disconnecting the lines and restoring them to their normal
condition after the expiration of the predetermined time limit.
54. A telephone system having a series of subscribers' stations provided with
signalling transmitters adapted for sending impulses over every line of the system
in sets or series; an automatic exchange station having a numerical receiver of
the first or units order; a series of numerical receivers of the second or tens
order; a series of numerical receivers of the third or hundreds order, and a
series of numerical receivers of the fourth or thousands order, together with means
for receiving the signalling impulses and additional means consisting of time
controlled separating devices and circuit connections for distributing said signalling
impulses to as many orders of receivers as there may be sets or series of signalling
impulses received.
55. In a system of telephonic intercommunication in which signalling impulses
in series or sets are transmitted to the exchange by individual subscribers for the
purpose of obtaining intercommunication with other lines, a time controlled
separating device for automatically separating the various series of impulses
transmitted by the signalling subscriber.
56. In an automatic telephone exchange station a series of subscribers' lines ;
means for automatically connecting any two of said lines together in combination
with a releasing device automatically placed in the circuit to enable either
subscriber to disconnect, and additional means consisting of a time controlled switch
and circuit connections for automatically controlling said releasing device at the
expiration of any predetermined time limit.
1001
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.