IMPROVEMENTS IN INDICATING OR SIGNALLING TIME BY MEANS OF ELECTRICITY AND IN APPARATUS EMPLOYED THEREIN
Year: 1883

page_text: LETTERS PATENT to Alfred George Brookes of 59 Chancery Lane in the
County of Middlesex Fellow of the Institute of Patent Agents, for an
Invention of "IMPROVEMENTS IN INDICATING OR SIGNALLING TIME BY MEANS
OF ELECTRICITY AND IN APPARATUS EMPLOYED THEREIN." Communicated to
him from abroad by Loren Noxon Downs of Boston in the State of
Massachusetts one of the United States of America.
PROVISIONAL SPECIFICATION left by the said Alfred George Brookes at
the Office of the Commissioners of Patents on the 28th December 1883.
ALFRED GEORGE BROOKES of 59 Chancery Lane in the County of Middlesex
Fellow of the Institute of Patent Agents IMPROVEMENTS IN INDICATING OR
"
SIGNALLING TIME BY MEANS OF ELECTRICITY AND IN APPARATUS EMPLOYED
THEREIN (communicated to me from abroad by Loren Noxon Downs of Boston in
the State of Massachusetts one of the United States of America)
This invention relates to a system of reporting time to the subscribers of a
telephone exchange system.
The object of the invention is to provide a method and apparatus by which the
subscribers of a telephone system may be provided with the correct time from a
single standard clock by signals repeated in continuous succession throughout all
the minutes of the day, and without the necessity of electric clocks, or dials, or in
fact any complex or additional apparatus whatsoever; thus avoiding any necessity
for the indefinite multiplication of electric clocks and the contingent expense and
complication of operation.
"
My invention contemplates the use of a single clock of the class known as
'repeaters."
By this term I mean one that strikes or makes some mechanical adjustment
other than the simple movement of the hands, for every hour and minute of the
day, which stroke or mechanical adjustment is when combined with the other
elements of my invention, made to transmit signals over the telephone lines to the
receiving instruments, and which signals, are by their measured rhythm, or by the

page_text: variation of the intervals between them, made to convey information relating to
the time to the subscriber by either the sound of the vibration of the telephonic
receiver diaphragms or by strokes on the subscribers signal bell. The first part of
my invention refers more particularly to the arrangement of circuits and
apparatus in which the signals are received upon the diaphragms of the receiving
telephones.
A repeating clock is so arranged as to repeat the time upon, say, the following
arbitrary system: The hours it strikes at intervals of two seconds of time, the
division of ten minutes, it strikes at intervals of one second of time and the
division of minutes it strikes at intervals of two thirds of a second. Thus at three
o'clock and fifty nine minutes, the clock would strike three strokes at intervals of
two seconds, five strokes at intervals of one second, and nine strokes at intervals of
3
5
9
two-thirds of a second, which may be illustrated thus 11111111111111111.
Then the next minute would be four o'clock, which would make the clock strike
4
four times with intervals of two seconds-thus, 1111. I use the term "strike "
here for convenience only, as repeating-clocks do always strike; but in the
application of such a clock in my invention the clock need not actually strike an
audible signal, but only make a mechanical adjustment to close and break an
electrical current (or vary the tension of an electrical circuit) in accordance with
such subdivision of time
In the central office may be provided in connection with suitable lines, a main
battery; a local battery, whose circuit is controlled by the clock; an electro-
magnet; its armature; back and front contacts; lines for three or other number of
subscribers, and of which there may be any number; the normal ground circuit,
or circuit through which call-impulses coining from the subscriber to the central
office find their way to the earth. The annunciators for the given number of
subscribers, and the spring jacks of the switch board, by means of which two
subscribers may be connected by plugs in the usual manner
The repeating clock is here described as being in the central office; but it is
obvious that its line wires may be extended sufficiently to place it in a watch-
makers or jeweller's shop, or in an observatory where it may be more conveniently
maintained under constant supervision as to correctness
Now this clock makes and breaks the circuit of the local battery, controlling the
electro-magnet of the central station and said circuit is normally broken so that
the armature rests back upon the back contact from the tension of its spring
whereby the normal ground circuit is closed, and gives to each subscribers line, a
terminal, at the ground in the central station.
Now, when in accordance with the system of signals before described the local
battery circuit is closed by the clock, the magnet attracts the armature. This
breaks the normal ground circuit, disconnecting certain lines from the ground at
the central office and at the same time closing the main battery circuit from the
front contact, through the armature, a section of the normal ground-circuit, and to
all the lines, producing in the receiver at the subscriber's end a sound by movement
of the diaphragm, and thence passing to earth. This movement of the diaphragm
is the audible time-signal for the subscribers, and as the clock divides such move-
ments into groups with different intervals of time between-as in the instance
given, 111 11111 111111111-the subscriber knows that it is fiftynine
minutes past three o'clock, or one minute of four. These signals do not interfere
with the use of the telephone for talking purposes, because the spring-jacks of
any two subscribers who may happen to be talking to each other are at that time
disconnected from the rest of the system
8
5
9
With this arrangement of the system when the signals are simple sounds of the
diaphragms in the subscribers' receivers made significant as to time by the arbitrary
intervals of time between them, only a weak battery-current is required, and this
is not sufficient to throw down the annunciators.

page_text: The second part of my invention refers to striking the signals upon the gongs of
the subscribers signal bells; I have found that the current necessary to do this
effectually, is a much stronger one than that employed in the foregoing method,
and as its passage over the lines would tend to excite the electro magnets of the
central station annunciators, and thus throw down the drop signals and produce
an infinite amount of confusion and embarassment in the operation of the said
central station I have provided and describe an effectual method and arrangement
for overcoming this difficulty
I employ between the magnet and its armature, a spring, which when the
armature, rests against the backstop, occupies a position between the stop and the
armature, but does not touch either. This spring, I connect by wire with
the branches of the subscriber's lines, while the armature is connected by wire with
the branches of the subscribers' lines. Now, then, two sets of wires, are connected
respectively, upon opposite sides of the annunciators, and any current which passes
through these two sets of branches from the central office is so weakened in the
electro magnets of the annunciators so as to have no effect on the latter. With
this arrangement, when the clock closes the local battery circuit and charges the
electro magnet, the armature moves forward till it strikes a spring and then both
move forward together till they both strike the front contact. The main battery
current, then passing through both the armature and spring and the two sets of
branches has no effect upon the doors of the annunciators, but nevertherless passes
into the several subscribers' lines in sufficient energy to ring the bells at the
subscribers stations, each of which bells is tapped upon by its hammer in accordance
with the prearranged system of signals as made by the clock, which bell signals
are generally audible through the room of each subscriber. As the armature moves
back again against the contact, it leaves the spring and renews the normal ground
circuit. To compensate for the resistance of the electro magnet of the annunciator,
which we will assume to be 25, differential resistances are placed in the two sets of
branches to balance the current. Thus for the first line, 50 may be placed in its
branch, which, with the 25 of the annunciator magnet, just balances the
75 resistance in that branch.
Resistances may also be placed in the shorter lines to equalize the effect of the
current on all the bells.
Thus the normal ground-circuit and local battery may be dispensed with and
the main-battery circuit controlled direct by the clock and distributed to the
several subscribers' lines.
In this invention the repeating clock need not necessarily make and break the
circuit by direct electrical connections, but may vary the electrical condition of
the line through sound-waves in the air acting upon a transmitter which may be
of ordinary construction, thereby sending induced or secondary currents over
the line.
The third part of my invention relates to the clock proper, or timing mechanism,
which is arranged to complete the circuit and charge a magnet every minute in.
the day.
This clock, together with its repeating mechanism which may be
extraneous to it, may be provided with a battery circuit within it. There is
provided a small electric motor, driven by a separate battery and circuit, or a
spring or weight movement. The clock gives the time and breaks the circuit at
regular intervals (say) of one minute, while the motor supplies the power for
shifting and adjusting the repeating mechanism by rotating shaft.
Whenever (every minute) the clock makes circuit and charges the magnet, an
armature is attracted, and this pushes bodily the slide-bar and simultaneously
throws the clutch to engagement with the arm and takes another arm out of the
slot in a disk, which disk is carried on a main shaft carrying the repeating cylinder.
The result is that the motor, through the clutch turns the shaft of the arın, and
this shaft, through a diminishing train of wheels, slowly causes the cylinder to
revolve one revolution, after which a spring pulls a stop into a slot of a disk and
stops the repeating cylinder. On the repeating-cylinder are three groups of pins,

page_text: one group, being arranged in rows, which rows contain pins from one to twelve
and between which pins of each row a space representing two seconds of time in
the revolution of the cylinder is left.
A group of pius representing the ten-minute division, may be ranged in rows
from one to five, and have a space between them representing a second of time.
The group of pins of the minute-subdivision, may be arranged in rows from one
to nine.
There are three levers, whose ends next to the cylinder are struck by the proper
pins and the levers deflected thereby
The first lever is in the row of three pins of the hour group, the next is in the
row of five pins of the ten minute division and the third lever is in the row of
nine of the minute subdivision, so that a revolution of the cylinder would deflect
the first lever three times at intervals of two seconds the second lever five times at
intervals of one second, and the third lever nine times at intervals of two thirds
of a second; and these levers being made one of the terminals of a battery-circuit
and the bar, another terminal of said circuit, it is easily understood how the local
current is broken into the significant signals of time. To shift the levers referred
to, to correspond with the passage of each minute of time the following mechanism
is provided to each of said levers is attached a slide bar, of which one lever has
ratchet teeth corresponding to the rows of pins, and of which another lever has
ratchet teeth corresponding to certain other rows of teeth whilst the third lever
has other teeth corresponding to certain other rows of teeth. Each of these
toothed slides is drawn to the right by spiral springs and as they are moved
against the tension of said springs they are held to said adjustment by separate
detents et cetera. The lower slide, represents minutes, and is acted on every minute,
and is closest to the cylinder. The next slide, above is farthest away from the
cylinder, and is acted on once in ten minutes (say) and the upper slide, is still
farther from the cylinder, and is acted on once every hour thus giving them the
proper adjustment in relation to the repeating pins to strike the successive times of
day in distinctive signals. For giving this adjustment to slides the end of the
cylinder is provided with a spring cam suitably pivotted and forced outwardly by
spring pressure till its upper end is held by a stop. A wing of this cam is inclined
to the plane of revolution, and by engaging with the teeth of the slide bars moves
them along.
In the lower slides, at the end of these series of teeth, there are two
slots, whose function is as follows: each revolution of the cylinder causes the wing
of the cam to enter a tooth of the lower bar and move it one tooth. After a
certain number of successive movements of this bar the one slot at the end of the
series comes into the plane of the wing and the latter is free from the action of
the spring to move outward still farther and move the second bar, Then, again, at
the end of certain such motions of the second bar another slot in said bar coincides
with the slot of the lower bar and the wing of the cam can penetrate still deeper
and move not only the lower and second bars but also the first bar, which latter is
moved only once in (say) sixty movements of the lower bar and indicates the
hours.
When the shoulders of the toothed slides strike certain detents et cetera, the
latter are thrown up and caught by a spring-hook, until an arın on the end of a
cylinder comes around and pulls the hooks away from the detents. Strokes of
certain levers on the before mentioned terminal bar are made to control the local
battery circuit and operate the armature; but when the signals are to be trans-
mitted through air vibrations impinging against a transmitter the stems are
extended and made to strike bells or other means adapted to produce the desired
audible indications

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Alfred George Brookes in the Patent Office on the 24th June
1884.
ALFRED GEORGE BROOKES of 59 Chancery Lane in the County of Middlesex
Fellow of the Institute of Patent Agents "IMPROVEMENTS IN INDICATING OR
SIGNALLING TIME BY MEANS OF ELECTRICITY AND IN APPARATUS EMPLOYED
THEREIN. (A communication to me from abroad by Loren Noxon Downs of
Boston in the State of Massachusetts one of the United States of America.)
This invention relates to a system of reporting time to the subscribers of a
telephone exchange system.
The object of the invention is to provide a method and apparatus by which the
subscribers of a telephone system may be provided with the correct time from a
single standard clock by signals repeated in continuous succession throughout all
the minutes of the day, and without the necessity of electric clocks, or dials, or in
fact any complex or additional apparatus whatsoever, thus avoiding any necessity
for the indefinite multiplication of electric clocks and the contingent expense and
complication of operation.
"
My invention contemplates the use of a single clock of the class known as
repeaters." By this term I mean one that strikes, or makes some mechanical
adjustment, other than the simple movement of the hands, for every hour and
minute of the day, which stroke or mechanical adjustment is, when combined with
the other elements of my invention, made to transmit signals over the telephone
lines to the receiving instruments, and which signals are by their measured rhythm,
or by the variation of the intervals between them made to convey information
relating to the time, to the subscriber, by either the sound of the vibration of the
telephonic receiver diaphragms or by strokes on the subscribers signal bell, as is
more fully hereinafter described.
Figure 1 of the drawings represents a diagram in which the time-signals to the
subscribers are made simply by the sound of the diaphragms of the receivers.
Fig 2 represents a diagram in which the signals are made upon the subscribers'
bells so as to be generally audible; and Figure 3 is a diagram representing a
simplified modification of my invention in which a local battery and the normal
ground-circuit are dispensed with, as bereinafter referred to. Figs 4, 4ª; 4b, and 4c
represent the internal construction of a repeating-clock such as I use with my
invention.
The first part of my invention refers more particularly to the arrangement of
circuits and apparatus, in which the signals are received upon the diaphragms of
the receiving telephones.
Referring to Fig. 1. A is a repeating-clock which is so organized as to repeat the
time upon (say) the following arbitrary system: The hours it strikes at intervals
of two seconds of time, the division of ten minutes it strikes at intervals of one
second of time, and the division of minutes it strikes at intervals of two-thirds of
a second. Thus at three o'clock and fifty-nine minutes, the clock would strike
three strokes at intervals of two seconds, five strokes at intervals of one second,
and nine strokes at intervals of two-thirds of a second, which may be illustrated
thus: 111. 11111. 111111111. Then the next minute would be four
o'clock, which would make the clock strike four times with intervals of two
8
5
4
9

page_text: invention the clock need not actually strike an audible signal, but only make a
mechanical adjustment to close and break an electrical current (or vary the tension
of an electrical circuit) in accordance with such subdivision of time.
As shown, the diagram in Fig 1 represents a central office, with the exception
of that portion to the left of the breaks in the lines at b, and the receiver to the
left of this represents one of the subscribers' stations. H is the main battery;
G the local battery whose circuit is controlled by the clock; E, an electro-magnet ;
B, its armature; N C, are back and front contacts; a a¹ a² lines for three sub-
scribers, and of which there may be any number; I I', the normal ground-circuit,
or circuit through which call-impulses coming from the subscriber to the central
office find their way to the earth. 1, 3, 5, are the annunciators for the three
subscribers, and 2, 4, 6 are the spring-jacks of the switch-board, by means of which
two subscribers may be connected by plugs in the usual manner.
The repeating clock A is here shown in the central office; but it is obvious that
its line wires may be extended sufficiently to place it in a watchmakers or jewellers
shop, or in an observatory where it may be more conveniently maintained under
constant supervision as to correctness.
9
3
5
Now this clock makes and breaks the circuit of the local battery G controlling
the electro-magnet E of the central station, and said circuit is normally broken so
that the armature B rests back upon the back contact N from the tension of its
spring whereby the normal ground-circuit I I' is closed and gives to each subscribers
line, a terminal at the ground in the central station. Now, when in accordance
with the system of signals before described the local-battery circuit is closed by the
clock, magnet E attracts armature B. This breaks at N the normal ground-circuit,
disconnecting lines a. a¹. a. from the ground at the central office and at the same
time closing the main-battery circuit from front contact C through the armature B
section I of the normal ground-circuit, and to all the lines a a¹ a³, producing in the
receiver R at the subscriber's end a sound by movement of the diaphragm and
thence passing to earth. This movement of the diaphragm is the audible time-
signal for the subscribers, and as the clock divides such movements into groups
with different intervals of time between as in the instance given, 111, 11111,
111111111-the subscriber knows that it is fifty-nine minutes past three
o'clock, or one minute of four. These signals do not interfere with the use of the
telephone for talking purposes, because the spring-jacks of any two subscribers
who may happen to be talking to each other are at that time disconnected from
the rest of the system. With this arrangement of my system, when the signals
are simple sounds of the diaphragms in the subscribers' receivers made significant
as to time by the arbitrary intervals of time between them only a weak battery-
current is required, and this is not sufficient to throw down the annunciators 1. 3. 5.
The second part of my invention refers to striking the signals upon the gongs of
the subscribers' signal bells; I have found that the current necessary to do this
effectually, is a much stronger one than that employed in the foregoing method
and as its passage over the lines would tend to excite the electro-magnets of the
central station annunciators, and thus throw down the drop signals and produce an
infinite amount of confusion and embarrassment in the operation of the said
central station, I have shown in Fig 2, and described, an effectual method and
arrangement for overcoming this difficulty.
I employ, between the magnet E and its armature B, a spring O, which, when
the armature B rests against the back stop N, occupies a position between the
stop C and the armature B, but does not touch either. This spring O, connect by
wire with the branches a³ a' a' of the subscribers' lines, while the armature B is
connected by wire I with the branches J. J. J% of the subscribers' lines. Now,
then, two sets of wires a³ a* a³ and J. J¹, J, are connected respectively; upon
opposite sides of the annunciators 1. 3. 5, and any current which passes through
these two sets of branches from the central office is so weakened in the electro-

page_text: magnets of the annunciators so as to have no effect on the latter. With this
arrangement, when the clock closes the local-battery circuit and charges the electro-
magnet E, the armature B moves forward till it strikes spring, O, and then both
move forward together till they both strike the front contact C. The main-battery
current, then passing through both B and O and the branches a³ a' a³ and J J¹ Ï'
has no effect upon the doors of the annunciators, but nevertheless passes into the
several subscribers' lines in sufficient energy to ring the bells at the subscribers'
stations each of which bells is tapped upon by its hammer in accordance with the
prearranged system of signals as made by the clock, which bell-signals are
generally audible through the room of each subscriber. As the armature B moves
back again against contact N, it leaves the spring and renews the normal
ground-circuit I'. To compensate for the resistance of the electro-magnet of the
annunciator, which we will assume to be 25, differential resistances are placed in the
branches as a a³ and J. J¹. J³, to balance the current. Thus, for line a* 50 is placed
in the branch J, which, with the 25 of the annunciator magnet, just balances the
75 resistance in branch a³. Resistances may also be placed in the shorter lines to
equalize the effect of the current on all the bells. In Figure 3 is shown in heavy
black lines, how the normal ground-circuit and local battery may be dispensed with
and the main battery circuit controlled direct by the clock and distributed to the
several subscribers' lines.
I am aware that it has been proposed to utilize telephone lines for signalling
time to a set of electrical clocks, and I do not claim any such arrangement. My
invention is distinctive, in the fact that only one clock is used, and that is a
repeater, and the signals sent to the subscribers are not made to act upon electric
clocks at such points, to give their hands a progressive movement; but said signals
are audible signals, possessing sufficient significance as to indicate of themselves the
time continuously through the day. This permits the telephone-circuits to be
utilized just as they stand without complication or interference, and dispenses with
the cost of a great number of electrical clocks. In my invention, the repeating
clock need not necessarily make and break the circuit by direct electrical
connections, but may vary the electrical condition of the line through sound-
waves in the air acting upon a transmitter, which may be of ordinary construction,
thereby sending induced or secondary currents over the line, as shown in dotted
lines in Fig 1.
In order to make my invention sufficiently clear as to enable any one skilled in
the art, to make and use it, I deem it best to describe one form of repeating-clock
of which only a general outline is shown in Figs 1, 2, 3.
The third part of my invention relates to the clock proper, or timing mechanism,
which is arranged to complete the circuit h³ and charge the magnet 22 every minute
in the day. This clock, together with its repeating mechanism which may be
extraneous to it, may be provided with a battery circuit h³ within it, which I have
represented in diagram. K' S* N* is a small electric motor, which is driven by a
separate battery and circuit (not shown) and which may be replaced by a spring or
weight movement. The clock X gives the time and breaks the circuit h³ at regular
intervals of one minute while the motor K2 S* N' supplies the power for shifting
and adjusting the repeating mechanism by rotating shaft K. Whenever (every
minute) the clock makes circuit h³ and charges the magnet 2, an armature j' is
attracted, and this pushes bodily the slide-bar H³ and simultaneously throws a
clutch J to engagement with the arm L' and takes another arm K' out of the siot
in a disk 1, (for side view of disk I see Fig 4") which disk is carried on the main
shaft carrying the repeating cylinder A'. The result is, that the motor, through
the clutch J, turns the shaft of the arm L, and this shaft through a diminishing
train of wheels, slowly causes the cylinder A² to revolve one revolution, after which
a spring 12 pulls a stop K* into a slot of a disk 12 and stops the repeating-cylinder.
On the repeating cylinder are three groups of pins, one group, o³, being arranged in

page_text: rows, which rows contain pins from one to twelve, and between which pins of each
row a space representing two seconds of time in the revolution of the cylinder
is left.
At p² is shown the group of pins representing the ten-minute division and these
are arranged in rows from one to five, and have a space between them representing
a second of time. At q² is shown the group of pins of the minute,-subdivision,
arranged in rows from one to nine.
B³ BB are three levers whose ends next to the cylinder are struck by the proper
pins o p q and the levers deflected thereby. As shown, lever B³ is in the row of
three pins of the hour group, B4 is in the row of five pins of the ten-minute division
and the lever B is in the row of nine of the minute-subdivision, so that a
revolution of the cylinder would deflect lever B³ three times at intervals of two
seconds, lever B4 five times at intervals of one second, and lever B³ nine times at
intervals of two-thirds of a second; and these levers being made one of the
terminals of battery-circuit G of Fig 1, and the bar M Fig 4, another terminal of
said circuit, it is easily seen how the local current in Fig 1 is broken into the
significant signals of time. To shift the levers B³ B' B' to correspond with the
passage of each minute of time the following mechanism is provided: To each of
said levers B3 B4 B is attached a slide-bar C3 C4 C5, of which C³ has twelve ratchet-
teeth corresponding to the twelve rows of pins, o², and of which C has five
ratchet-teeth corresponding to the five rows of pins p² while C has nine teeth
corresponding to the nine rows of teeth, q². Each of these toothed slides is drawn
to the right by spiral springs b³ 6 6, and as they are moved against the tension of
said springs they are held to said adjustment by separate detents D³ et cetera. The
lower slide.C³, represents minutes and is acted on every minute, and is closest to
the cylinder A. The next slide C, above is farthest away from the cylinder, and
is acted on once in ten minutes, and the upper slide C³ is still farther from the
cylinder, and is acted on once every hour, thus giving them the proper adjustment
in relation to the repeating-pins.o² p² q² to strike the successive times of day in
distinctive signals. For giving this adjustment to the slides C3 C4 C5 the end of
cylinder A is provided with a spring cam F2. Fig 4%, pivoted at m and forced
outwardly by spring g² till its upper end is held by a stop. The wing h² of this
cam is inclined to the plane of revolution, and by engaging with the teeth of the
slide bars C3 C4 C³, moves them along. In the lower slides, C³ and C, at the end of
these series of teeth, there are slots s s¹, Fig 4°, whose function is as follows:
Each revolution of the cylinder A2 causes the wing 2 of the cam F² to enter a
tooth of the lower bar C³, and move it one tooth. After nine successive move-
ments of this bar the slots at the end of the series comes into the plane of the
wing 2, and the latter is free from the action of the spring 92 to move outward
still farther and move the second bar C. Then, again, at the end of five such
motions of bar C the slot s¹ in said bar coincides with slot 8 of bar C, and the
wing h² of the cam can penetrate still deeper and move not only bars C³ and C
but also the bar C³, which latter is moved only once in sixty movements of bar C³
and indicates the hours.
When the shoulders a³ a a³ of the toothed slides strike detents D³ et cetera the
latter are thrown up, and caught by spring hook E' until arm N³ on the end of
cylinder A² comes around and pulls the hooks away from the detents. As shown
the strokes of levers B³ B4 B5 on bar M are made to control the local-battery
circuit G and operate the armature E of Fig 1.; but when the signals are to be
transmitted through air vibrations impinging against a transmitter the stems cc' c³
are extended and made to strike annunciators or the bells shown in dotted lines.
I am aware that heretofore and prior to my invention time has been distributed
by electric clocks, or dials, governed by a standard or central clock; but in such
cases it has always been found necessary to place a separate clock or dial, at each
point where the time was to be given, whereas, by my invention a single clock
suffices for the whole.

page_text: Having thus described the nature of this invention, and the manner of its
operation, I claim :-
1. The method hereinbefore described of distributing or supplying standard or
correct time to any number of subscribers or substations in a telephonic system
which consists in continuously making and breaking (or varying the electric
condition of) the main circuit into significant signals, having different intervals of
time between the signals of the several groups denoting different subdivisions of
time, whereby the audible signals are made recognizable and significant as to time
in each receiver, separate receiving clocks are dispensed with, and the simplicity
and efficiency of the telephonic system preserved without interference or
interruption.
2. The combination of a central telephone station; a series of sub-stations
therefor; receiving telephones, and signal bells at the said substations; a clock of
the character described, at the central station; and repeating devices substantially
as herein shown and specified, whereby the signals of the said clock may be
repeated upon any or all of the substation receiving instruments.
3. The method of striking standard time upon the signal bells of any number of
subscribers in a telephone exchange system, which consists in continuously making
and breaking the electric current into recognizable signals, having different
intervals of time between the signals of the several groups, and dividing this
current at the central office upon opposite sides of the annunciators to prevent the
dropping of the annunciator signals-as described.
4. The combination, with a telephone system and a suitable battery, of a clock,
constructed as described, to repeat continuously throughout the whole day, and
break or vary the current on the line into recognizable significant signals of time,
as described.
5. The combination, with the bells of the receivers, their several lines, and their
annunciators and jacks, of a repeating-clock, a local circuit controlled thereby, an
electro-magnet operated by said circuit, a main line circuit, and the armature B
and spring O, connected respectively, to branch lines leading to the opposite sides
of the subscribers' annunciators, as and for the purpose set forth.
In witness whereof I the said Alfred George Brookes have hereunto set my hand
and seal this twenty third day of June in the year of our Lord One thousand,
eight hundred and eighty four.
ALT
ALT RED G BROOKES
(44.5.)