IMPROVEMENTS IN TELEPHONE SIGNAL APPARATUS, AND IN KEEPING CLOCKS IN UNISON
Year: 1880

page_text: LETTERS PATENT to William Morgan-Brown, of the Firm of Brandon and
Morgan-Brown, Engineers and Patent Agents, of 38, Southampton Buildings,
London, and 1, Rue Laffitte, Paris, for an Invention of "IMPROVEMENTS IN
TELEPHONE SIGNAL APPARATUS, AND IN KEEPING CLOCKS IN UNISON."
communication from abroad by George Henry Bliss, of Pittsfield, 'Berkshire,
Massachusetts, United States of America.
A
PROVISIONAL SPECIFICATION left by the said William Morgan-Brown at
the Office of the Commissioners of Patents on the 23rd January 1880.
WILLIAM MORGAN-BROWN, of the Firm of Brandon and Morgan-Brown,
Engineers and Patent Agents, of 38, Southampton Buildings, London, and 1, Rue
Laffitte, Paris. IMPROVEMENTS IN TELEPHONE SIGNAL APPARATUS, AND IN
KEEPING CLOCKS IN UNISON." [A communication from abroad by George Henry
Bliss, of Pittsfield, Berkshire, Massachusetts, United States of America.]
«
This Invention relates to a method of operating telephone calls, and consists in
an armature controlling device operated by a clock or time-train to render the
signal bell of each telephone of a circuit inoperative except at a certain moment,
the moment or exact time for operating each signal bell in the circuit being different
at each telephone in the circuit, and being known at the central office, so that by
breaking the circuit from the central office at the proper moment the signal for any
telephone or instrument in a circuit may be operated without disturbing any other
signal in the circuit, thereby obviating the now disagreeable sounding in each
office occupied by a telephone, and watching for a certain number of strokes of the
bell to indicate that office.
The Invention also consists in means for automatically regulating the movement
or correcting the time of the different clocks or time trains in the circuit, and
keeping them in unison with a central clock for each circuit located at the central
office.
Also in means to shunt the circuit around the electro-magnet of each signal
while the said signal is inoperative, whereby the battery power required is
only enough to operate a single electro-magnet in the circuit, all the others being
shunted.
Each signal is rendered operative in its turn, the shunt around its clectro-magnet

page_text: being broken, and then at the proper moment the shunt is closed and that of the
next signal in order broken.
In the present embodiment of this Invention the hammer of the usual signal
bell, operated in the usual manner by an electro magnet, is provided with an arm
or lever suitably weighted to counterbalance the hammer of the bell and hold it
from falling back when the circuit is broken, thereby preventing the hammer striking
the bell and giving a signal as it would otherwise do when the circuit was again
closed in the usual manner of giving signals.
Suitable connections are provided between the weight and a time train or clock
movement to raise the said weight and hold it elevated for a suitable time, usually
about four seconds, at suitable intervals, say once a minute, during which time,
and at no other time, the signal, when the weight is so lifted may be sounded as
usual.
The times for operating each signal are different for the different telephones in
the same circuits, as, for instance, a telephone A may have its signal operative
between 5 and 9 seconds after each minute, while a signal of telephone B may be
operative between 10 and 14 seconds, and so on, this allowing ten telephones for
each circuit, and permitting the signal of each telephone to be operated at least once
in a minute, such division of time allowing time to signal the central office without
interfering with the other signals of the circuit, and to regulate the clocks or time
trains of the circuit which drive the armature controlling devices, as will be
hereinafter described.
The weight for holding the armature forward is attached to a suspending rod
connected at its upper end with one end of a bar pivotted at its other end to the
frame-work or one of the usual arbors of the clock, and provided near its middle
portion with a lug situated above and adapted to be operated by the armature
controlling device set in motion or rotation by one of the arbors of the clock,
preferably that carrying the second hand, it consequently rotating the said device
once a minute.
This armature controlling device is a disk provided with a cam or projection and
attached to a secondhand arbor, the said cam or projection at every revolution
striking the lug on the lever, raising the said lever and its connected suspending
rod to lift the weight and leave the bell hammer free to respond to the electro
magnet if the current is then broken at the central office.
The said cam or projection is sufficiently broad to hold up the lever and weight
for the proper interval, and its face should be inclined so as to allow the lever
and weight to sink gradually when closing the armature against the electro-
magnet, so as not to ring the bell in case the circuit happens to be open.
These cams are placed in a different position in each clock connected with each
of the different telephones of the circuit, so that the time for operating the signals
of each telephone shall be different.
Connected with the suspending rod carrying the weight is employed a circuit-
closer to close a shunt circuit to thereby shunt the electro magnet and remove its
resistance from the circuit operating the said signals. It is obvious that merely
shunting the electro magnets is sufficient to render the signals inoperative, but in
such case each bell would give a tap when its shunt was broken, to obviate which
a weight is made use of to render the bell hammer inoperative.
In order to keep the clocks in unison, or so that the second hand points to the
same figure in all the clocks of each telephone circuit, the automatic clock or time
train is provided with a stop which, at suitable intervals, as once an hour (but it
may be easily more or less that an hour), stops all the clocks of each circuit with
the second hand at o, after which all the clocks of the circuit are automatically
started from the central clock when the clock at the central office comes to the o
point.
Thus by regulating the speed of all the clocks in each circuit by the usual
regulators so that they run nearly accurately (but a trifle fast) they may be all held
back at the end of each hour for a second or any fraction thereof which they may

page_text: have gained, thereby enabling all the clocks of the circuit, by the usual regulators
to be kept so as to never vary a whole second, which is near enough for practical
operation.
This operation of correcting the clocks and securing unison of time and movement
may be accomplished in the following manner :-
The cam disk before mentioned has a second pin or projection so located thereon
that when the second hand is at o it is in proper position to be engaged by a catch
on a bar pivotted beneath the cam, the said pivotted bar being so connected
with the bell hammer by a second link or cord and arm similar to that before
described in connection with the weight, that its catch can only engage the pin of
the cam when the bell hammer is back, that is, when both the weight is lifted and
the circuit is open, which two conditions are brought about once an hour (or at
other required intervals) in the following manner :-
The cam-projection is so arranged that, by its action alone, the weight before
described is never lifted at the proper moment to permit the stop-catch to act, but
a wire is attached to the weight lifting arm in proper position to engage a rod
connected with the hour hand arbor at the proper moment to hold the weight arm
up for a short interval of time after it has been raised by the said cam projection,
thus leaving the bell hammer free to fall back when the circuit is opened, which is
automatically done about three minutes before the second hand arrives at o by a
switch connected with the central clock at the central office, thus leaving the
stop catches in all the clocks of the circuit free to engage and stop the said clocks
with their second hands at o, till at the proper moment the clock at the central
office automatically closes the circuit and rings the signal bells, and by the
connections frees the stop catches and starts the clocks all in unison.
This method of keeping clocks in unison may be of use in other than telephonic
circuits.
It is obvious that the signal may be operated in accordance with the principle
of the Invention by either the armature controlling or shunting device alone
independent of the other, but it is preferable to use both together, as will be
hereinafter described.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by the
said William Morgan-Brown in the Great Seal Patent Office on the 22nd July
1880.
WILLIAM MORGAN-BROWN, of the Firm of Brandon and Morgan-Brown, Engineers
and Patent Agents, of 38, Southampton Buildings, London, and 1, Rue Laffitte,
Paris. "IMPROVEMENTS IN TELEPHONE SIGNAL APPARATUS, AND IN KEEPING
CLOCKS IN UNISON." A communication from abroad by George Henry Bliss, of
Pittsfield, Berkshire, Massachusetts, United States of America.
This Invention relates to a method of operating telephone calls, and consists in
an armature-controlling device operated by a clock or time train to render the
signal bell of each telephone of a circuit inoperative except at a certain moment,
the moment or exact time for operating each signal bell in the circuit being different
at each telephone in the circuit, and being known at the central office, so that by
breaking the circuit from the central office at the proper moment the signal for any
telephone or instrument in a circuit may be operated without disturbing any other
signal in the circuit, thereby obviating the now disagreeable sounding in each office
occupied by a telephone, and watching for a certain number of strokes of the bell
to indicate that office.
The Invention also consists in means for automatically regulating the movement
or correcting the time of the different clocks or time-trains in the circuit, and
keeping them in unison with a central clock for each circuit located at the central
office.
Also in means to shunt the circuit around the electro magnet of each signal
while the said signal is inoperative, whereby the battery power required is only
enough to operate a single electro magnet in the circuit, all the others being
Bhunted.
Each signal is rendered inoperative in its turn, the shunt around its electro
magnet being broken, and then at the proper moment the shunt is closed, and that
of the next signal in order broken.
In the present embodiment of this Invention the hammer of the usual signal bell,
operated in the usual manner by an clectro magnet shown, is provided with an
arm or lever suitably weighted to counter-balance the hammer of the bell, and hold
it from falling back when the circuit is broken, thereby preventing the hammer
striking the bell and giving a signal as it would otherwise do when the circuit was
again closed in the usual manner of giving signals.
Suitable connections are provided between the weight and a time train or clock-
movement to raise the said weight and hold it elevated for a suitable time, usually
about four seconds, at suitable intervals, say once a minute, during which time
and at no other time the signal, when the weight is so lifted, may be sounded as
usual.
4
The times for operating each signal are different for the different telephones in
the same circuit, as for instance, a telephone A may have its signal operative
between 5 and 9 seconds after each minute, while a signal of telephone B may be
operative between 10 and 14 seconds, and so on, this allowing ten telephones for
each circuit, and permitting the signal of each telephone to be operated at least 4
once in a minute, such division of time allowing time to signal the central office
without interfering with the other signals of the circuit, and to regulate the clocks
or time-trains of the circuit which drive the armature-controlling devices, as will be
hereinafter described.
As herein shown, the weight for holding the armature forward is attached to a
suspending rod connected at its upper end with one end of a bar pivotted at its
other end to the framework, or one of the usual arbors of the clock, and provided
near its middle portion with a lug situated above and adapted to be operated by

page_text: the armature-controlling device set in motion or rotation by one of the arbors of
the clock, preferably that carrying the second hand, it consequently rotating the
said device once a minute.
This armature controlling device is herein shown as a disc provided with a cam
or projection, and attached to a second hand arbor, the said cam or projection at
every revolution striking the lug on the lever, raising the said lever and its con-
nected suspending rod to lift the weight and leave the bell hammer free to respond
to the electro inagnet if the current is then broken at the central office.
The said cam or projection is sufficiently broad to hold up the lever and weight
for the proper interval, and its face should be inclined so as to allow the lever and
weight to sink gradually when closing the armature against the electro magnet, so
as not to ring the bell in case the circuit happens to be open.
These cams are placed in a different position in each clock connected with each
of the different telephones of the circuit, so that the time for operating the signals
of each telephone shall be different.
Connected with the suspending rod carrying the weight is employed a circuit-
closer to close a shunt circuit to thereby shunt the electro magnet, and remove its
resistance from the circuit operating the said signals. It is obvious that merely
shunting the electro magnets is sufficient to render the signals inoperative, but in
such case each bell would give a tap when its shunt was broken, to obviate which
a weight is made use of to render the bell hammer inoperative.
In order to keep the clocks in unison or so that the second hand points to the
same figure in all the clocks of each telephone circuit, the automatic clock or time
train is provided with a stop, which at suitable intervals, herein shown as once an
hour (but it may be, easily, more or less than an hour), stops all the clocks of each
circuit with the second hand at o, after which all the clocks of the circuit are
automatically started from the central clock when the clock at the central office
comes to the o point.
Thus by regulating the speed of all the clocks in each circuit by the usual
regulators so that they run nearly accurately (but a trifle fast) they may be all held
back) at the end of each hour for a second or any fraction thereof which they may
have gained, thereby enabling all the clocks of the circuit by the usual regulators
to be kept so as to never vary a whole second, which is near enough for practical
operation.
This operation of correcting the clocks and securing unison of time and movement
may be accomplished in the following manner :-
The cam disc before mentioned has a second pin or projection so located thereon
that when the second hand is at o, it is in proper position to be engaged by a catch
on a bar pivotted beneath the cam, the said pivotted bar being so connected with
the bell hammer by a second link or cord and arm similar to that before described in
connection with the weight, that its catch can only engage the pin of the cam when
the bell hammer is back, that is, when both the weight lifted and the circuit is
open, which two conditions are brought about once an hour (or at other required
intervals in the following manner :-
The cam projection is so arranged that by its action alone the weight before
described is never lifted at the proper moment to permit the stop catch to act, but
a wire is attached to the weight lifting arm in proper position to engage a rod
connected with the hour hand arbor at the proper moment to hold the weight arm
up for a short interval of time, after it has been raised by the said cam-projection,
thus leaving the bell hammer free to fall back when the circuit is opened, which
is automatically done about three minutes before the second hand arrives at o, by a
switch connected with the central clock at the central office, thus leaving the
stop-catches in all the clocks of the circuit free to engage and stop the said
clocks with their second hands at o, till at the proper moment the clock at the
central office automatically closes the circuit and rings the signal bells, and by the
connections frees the stop-catches and starts the clocks all in unison.

page_text: This method of keeping clocks in unison may be of use in other than telephonic
circuits.
It is obvious that the signal may be operated in accordance with the principle
of the Invention by either the armature controlling or shunting device alone
independent of the other, but it is preferable to use both together, as will be
hereinafter described.
Figure 1 shows a front view of a telephone signal bell and attached clock
provided with these improvements, the usual clock dial being omitted, but such
dial is shown in another Figure.
Figure 2, a rear side elevation of the clock at the central office with its devices
for making and breaking the current to start the clocks in circuit with it.
Figures 3 and 4, details of Figure 2.
Figure 5, the dial removed from Figure 1.
Figure 6, a detail showing the lever which is acted upon by the armature
controlling device to lift the weight at the proper time, and release the armature
with the armature-controlling device in front edge view, and Figure 7, a detail
shewing a modification of the shunt circuit closer.
The bell a, the electro magnet b with its armature c, and connected bell hammer
cl pivotted at d, and in circuit are common to telephone signals, and need not
therefore be further described.
The binding screws u, v, upon the frame a¹ to which the main signal circuit wire
is connected, and between which the coils of the electro magnet 6 are interposed
are respectively connected with the shunt wires 12, 13, which dip into mercury
contained in the cups x, Y. It is obvious that when electrical connection is
established between the ends of the wires 12, 13, or between the mercury in the
cups x, y, by the circuit closer hereinafter described, the electro magnet b will be
shunted, and its resistance removed from the main signal circuit, so that the
strength of battery required is correspondingly reduced.
The armature c has attached to it a lever arm dadapted to be acted upon
by a weight e of sufficient amount to hold the hammer c¹ against the bell when the
circuit is open, and the armature is not attracted by the magnet, the said weight e
being connected by a suspending rod f, with one end of the lifting arm g pivotted
at its other end to the arbor g₁ on to the frame h of the clock work, which is of
any usual construction.
The circuit closer used to establish connection between the wires 12, 13, is
shown as a forked wire 14 having its ends in the cups x, y, and carried by the
suspending rod f in such manner, that when said suspending rod is in its lowest
position, the ends of the said wires 14 dip in the mercury in the said cups, thereby
completing the shunt around the electro magnet b. It is obvious that any other
device may be used to complete the shunt, as, for example, that shown in Figure 3,
where the wire 14 is V shaped and forms direct electrical connection between the
wires 12, 13, which are bent into convenient form to engage the said wire 14.
The lifting arm g is provided near its middle with a lugh to engage the cam
projection on the cam discj which controls the armature, the cam disc turning
on the same arbor and in unison with the second hand k, so that the said
lifting arm in each clock is raised once a minute and lifts the weight e, and thereby
leaving the armature c and bell hammer c¹ free to act.
This cam projection is of sufficient width to retain the weight elevated for a
suitable number of seconds, and is inclined as at 2 (see Figure 6) to allow the weight
to fall back gradually, so as not to give a signal if the circuit happens to be open.
These cam projections are at different positions on the different clocks of the
circuit.
The one shown in the Drawing is arranged to operate when the second hand
is at 50.
A table is kept at the central office showing the operating time of each
telephone in the circuit,

page_text: To call the telephone shown in the Drawing, the operator at the central office
would break and close the circuit a few times just when the second hand of the
central clock was at 50, at which moment the signal bell connected with the
clock shown in the Drawing, and that bell alone of all bells in the circuit, would
sound.
A certain number of seconds will be reserved by the cam disc for signaling the
main office.
Between the points 56 and o cams or projections are omitted from all the
armature controlling devices of the circuit, as this time or space is required once
an hour or at other required intervals, for correcting the clocks in the circuit,
which is done by the following mechanism :-
The cam disc j has a second pin or projection a² so placed as not to interfere with
the lifting arm g, it being however in proper position to be engaged when the
second hand is at o, by the catch on the stop arm m pivotted at o and counter-
balanced at one end as at 4, so as to raise the catch into position to engage the said
pin a².
The other end of the stop arm is connected by a link m³ with a lever n similar
to the one which holds the weight e.
This arrangement permits the catch on the stop arm to rise only when the bell
hammer is back, that is, when both the weight e is raised and the circuit is open,
a combination of circumstances which is brought about in the following manner :-
The lifting-arm is provided with a wire o² suitably formed to be held up by the
end of an shaped rod p attached to the hour hand arbor and rotating therewith,
the shaped portion of which is of a length to be passed over in just one minute,
and is turned away from the end of the wire o².
The shaped rod is elastic, and bears against the end of the wire o just before
it is raised by the cam i when the end of the L shaped arm slips under the wire o
and holds it, and the connected arm g with the shunt circuit closer 14 and weight e
up for the space of a minute, thus leaving the bell hammer free to fall back upon
the opening of the circuit, which is accomplished, when the central clock second
hand is about at 58, by a switch which may be as shown in Figures 2 to 4.
In this switch, the wire 5 is shown connected with one wire of the circuit, and is
twisted as at 6, to from a spring by which its free end contracts with one fork of
the shaped portion 7 connected with the other wire of the circuit.
Just at the proper time an arm 8 rotated by the central clock C bears against
the wire 5, moving it towards the other fork of the U shaped wire, and when it is
between the two forks the circuit is broken, allowing the catches to stop the clocks,
and then by a further movement the said wire touches the other arm of the fork,
and again closes the circuit, thereby through suitable connections, as described,
simultaneously starting all the clocks of the circuit with their second bands in like
positions.
In this latter operation just described, it is obvious that when the shunting
device is used in connection with a correspondingly weak battery, the armatures
will fall back before the opening of the circuit by the clock at the central office,
and in this case an additional battery will be needed to attract all the armatures
simultaneously to start the clocks. This additional battery power may be readily
interposed by the switch operated by the central clock, or it may be added in the
circuit by the operator at the proper time.
The bell may be rendered incperative except at the proper time by means of a
damper operated in a similar manner to the weight e.
The shunt circuit-closer may be a rotary one carried by an independent portion
of the clockwork from that actuating the link e and weight f. It is evident that
the signal may be operated by the shunt and circuit closer alone, independent of
the weight e, but in that case the bell-hammer would fall back when the shunt was
closed, and then give a tap when it was again broken, also that it may be operated
by the armature-controlling device independent of the shunt, but in this case
sufficient battery will be required to operate all the bells at once.

page_text: The instruments or means employed to determine the intervals for sounding
signals, and for correcting the time of and starting the clocks, may be such as to
make said intervals of longer or shorter duration, as described.
An essential feature of this system is to arrange the bell of the signal apparatus,
and the hammer and its operating parts, so that the bells at the different offices of
the circuit in which they are placed shall not operate, or be capable of being
operated at the same time.
Sounding an alarm or signal by clock work alone or by electricity is not broadly
claimed.
The Drawing shows the clock and signal of but one telephone station, but it will
be understood that similar parts are placed in the room occupied by each telephone
of the circuit, the cam wheel ; however having their projections i differently
located.
In Figure 1 the L shaped arm has acted upon the wire o³ and lifted the lever g
and weight, and the lever m has been raised to engage projection a³, and the clock
is stopped ready to be released by the switch or current breaker shown in Figures
2 to 4.
Having now described and particularly set forth the nature of the said Invention,
and the manner of carrying the same into effect, I would have it understood that
what I claim is,―
First. A clock or time train combined with a bell or other signal, and an electro
magnet to operate it, and connecting devices between the time train and signal
controlled by the time train, to render the said signal silent at all times except at
predetermined exact intervals of time, to thereby permit the said signal to be
Bounded only at predetermined intervals of time, to avoid sounding more than one
bell or signal in each circuit at one time, substantially as described.
Second. A clock or time train, a signal bell, and electro-magnet to operate it, and
a shunt circuit to shunt said electro magnet, one portion of said shunt circuit being
composed of a circuit closer controlled by the said time train, whereby the said
electro-magnet is shunted during certain intervals of time, substantially as
described.
Third. In a telephonic circuit, a series of clocks or time trains, and bells operated
by electro-magnets, the armatures of which are adapted to be released by a break
in the electric current, combined with a series of arinature controlling devices, each
of which, in all the clock or time trains of the circuit, is adapted to release the
armature of its own electro magnet at a different time from any of the others,
whereby any signal in connection with any telephone of the circuit may be called
at a predetermined and definite time, and at no other time, at which time all the
other armatures which operate all the other bells of the circuit are mechanically
and positively held closed to thereby permit but one telephone of the circuit to be
sounded at the same time, substantially as described.
Fourth. In a telephonic circuit, a series of clocks or timo trains and signal bell's
operated by electro magnets, combined with a series of circuit closing-devices, to
close a shunt around the said electro magnets, each one operated by the said time
trains to open the shunt and cause the current to pass through the coils of the
corresponding electro magnet at a different time from any of the others, whereby
all the signals in the circuit may be operated each in turn by a battery of sufficient
power to operate one, substantially as described.
Fifth. A time train or clock to operate an armature controlling device in a
telephonic circuit, and automatically release an armature at stated intervals to
permit it at that time, and only at that time, to be operated by a break of the
battery-current combined with a check or stop to temporarily arrest the motion of
the clock or time train at regular intervals of time, to permit each clock or time
train in the telephonic circuit to be stopped at regular intervals of time, preparatory
to being again started together, to insure uniformity of time or speed of movement
of the armature releasing devices of all the clocks of the circuits, substantially as
described.

page_text: Sixth. A time train or clock to operate an armature controlling device in a
telephonic circuit, and automatically release an armature at stated intervals, to
permit at the proper time, and only at that time, to be operated by a break of the
battery current, combined with a check or stop to temporarily arrest the motion of
the clock or time train at regular intervals of time, to permit each clock or time
train in the telephonic circuit to be stopped at regular intervals, and with a central
clock in electric connection with all the other clocks of the circuit, and circuit
breaking devices or switch operated by the said central clock, whereby the clock or
clocks in circuit with the central clock may be automatically started at the same
defined time, as and for the purpose set forth.
Seventh. In combination, one of the main arbors of a clock, an arm, and
connections to raise the weight which holds the armature closed against the poles
of its magnet, preparatory to breaking the current of the circuit in which the said
magnet is placed, and a stopping device released by the movement of the said
magnet when the current is broken, the said stopping device engaging a projection
moving in unison with the second hand of the clock, and automatically stopping it
at certain premeditated intervals, substantially as described.
Eighth. In a telephonic call or signal apparatus, a time train or clock, and
armature and electro magnet combined with a weight to hold the armature closed
mechanically except for a certain number of seconds at regular intervals, when the
said weight is raised to release the armature, and permit it to be operated by the
battery current if desired, the bell or signal being noiseless at all other times,
substantially as described.
In witness whereof, I, the said William Morgan-Brown, have hereunto set my
hand and seal, this Twenty second day of July, in the year of our Lord
One thousand eight hundred and eighty.
WILLIAM MORGAN-BROWN. (L.S.)