IMPROVEMENTS IN THE METHOD OF AND MEANS FOR UTILIZING ELECTRIC CIRCUITS FOR VARIOUS PURPOSES, SUCH AS TELEPHONIC OR TELEGRAPHIC COMMUNICATION, CON- TROLLING OR SYNCHRONIZING TIME MEASURERS, FIRE OR BURGLAR ALARM SYSTEMS, OR THE LIKE."
Year: 1881

page_text: ETTERS PATENT to William Fletcher Barrett, of Monkstown, in the County
of Dublin, Ireland, Fellow of the Royal Society of Edinburgh, &c., Professor
of Physics in the Royal College of Science, Stephen's Green, in the City of
Dublin, in the said County, for an Invention of "IMPROVEMENTS IN THE
METHOD OF AND MEANS FOR UTILIZING ELECTRIC CIRCUITS FOR VARIOUS
PURPOSES, SUCH AS TELEPHONIC OR TELEGRAPHIC COMMUNICATION, CON-
TROLLING OR SYNCHRONIZING TIME MEASURERS, FIRE OR BURGLAR ALARM
SYSTEMS, OR THE LIKE."
PROVISIONAL SPECIFICATION left by the said William Fletcher Barrett
at the Office of the Commissioners of Patents on the 27th October 1881.
WILLIAM FLETCHER BARRETT, of Monkstown, in the County of Dublin, Ireland,
Fellow of the Royal Society of Edinburgh, &c., Professor of Physics in the Royal
College of Science, Stephen's Green, in the City of Dublin, in the said County.
"IMPROVEMENTS IN THE METHOD OF AND MEANS FOR UTILIZING ELECTRIC
CIRCUITS FOR VARIOUS PURPOSES, SUCH AS TELEPHONIC OR TELEGRAPHIC COж-
MUNICATION, CONTROLLING OR SYNCHRONIZING TIME MEASURERS, FIRE OR
BURGLAR ALARM SYSTEMS, OR THE LIKE."
My Invention relates to a method whereby a line used for telephonic or telegraphic
purposes may also be employed for the purpose of keeping clocks or other time
measurers in unison, for giving notice of burglaries or fires, or for other purposes,
and which can be especially adapted to special safes for burglar or fire detection.
For this purpose I make use of Retchie's or other system of periodic time control
from a central station, and my Invention consists in adapting to the controlling and
controlled clocks electric contacts, which the clock automatically opens and closes at
certain times. During the day, or such times as may be most convenient, the
controlling and controlled clocks each complete the circuit loading from the line
wire to the telephonic or telegraphic apparatus, except for a short period, say 10 to
30 seconds, when the telephone circuit is broken and the line placed in the clock
controlling circuit.
The normal clock is allowed then to regulate the controlled clock, and after a few
seconds the line is again thrown to the previous telephonic or telegraphic circuit.
At night-time the line is or can be placed by means of the clockwork out of the

page_text: telephonic or telegraphic circuit and on to the circuit of the fire or burglar alarm,
the adaptation to one or two forms of which are hereafter described. The clock
control is still carried on during the night as during the day by the automatic
action of the clockwork. There may be also a third or fourth distribution of the
line current for any other purpose, the circuit of which the clock may automatically
completo. Thus the clock may at a given time and for a given period throw into
circuit an electric call for workmen, so that the time of coming to work will be
automatically sounded, or it may be used to indicate the performance of an engine
or other machinery at given periods, or record steam or other pressure.
Further, the line wire may be led to positions accessible to policemen on duty,
who, on the breaking out of a fire or other danger, can unlock a box containing a
contact key, and by opening and closing the circuit to transmit a system of precon-
certed siguals, and so at once notify the fact to the central station, where the
particular locality will be indicated by the same or a similar arrangement to that
used in the day to indicate the calls by telephone or otherwise.
The clock may also be used as an indicator that a watchman regularly goes his
rounds. For this purpose special addition is made to the clockwork.
The special arrangements used in connection with my Invention for detecting
burglary or fire may be such as (1) an air tight safe, with a means of rendering the
pressure within rarer or deuser than that of the atmosphere, the equilibrium being
established, and thereby an electric or pneumatic circuit broken or completed, when
the safe is forced or when an outbreak of fire occurs; or (2) a network of wire in
one continuous circuit may envelope the interior of the safe, which network will
be ruptured and the current broken when the safe is broken into; in this case, in
the electric circuit exterior to the safe, any form of fire alarm may be introduced.
As an example of carrying out my Invention the line wire may enter the central
station, and be in contact with an insulated spring detent standing at right angles
to the circumference of a disc mounted on the cannon pinion of the centre arbour
of the clock, and having a notch in its circumference into which a pin on the
detent falls into as the clock goes round, say every hour. The detent is thinned
into a spring at two places. When the pin falls into the notch contact is made
between a contact pin carried by the free end of the detent and another insulated
contact piece, the current then passing off by a wire to the controlling electro
magnet, such as that known to electricians as "Ritchie's." As the clock further
goes on the pin is lifted from the notch, and the contact pin at the free end of the
detent breaks the circuit, and the other end of it on rising touches either one of
two contact pieces (such as for the telephone or telegraph and police lines respec-
tively) fixed close to, but not in contact with, each other on the under surfaco of a
non conducting horizontal bar moving on a pivot, and being kept in position by a
vertical arm of a horizontally pivoted shaft passing upwards through a slot in the
said bar, so that either contact piece is alternately presented, say, every twelve hours
by such arrangement.
The said arin has a horizontal pin resting on the surface of a ratchet wheel
having 24 points, moved one tooth each hour by the minute wheel, and held by a
spring pawl. Half the surface of this wheel is raised, and so communicatos the
changing motion to the horizontal bar required to change the aforesaid contacts
alternately at 12 hour intervals; a heel spring presses down the vertical arm on the
wheel.
Should the circumstances of any individual clock so require it, a separate arm or
lever may act instead of the single lever and pin, so as to lead off on each side of
the shaft; or the lever may terminate in a spring at the base instead of a pivoted
shaft; or the detent may be pivoted, or the horizontal bar terminate in a spring
instead of moving on a pivot; or a detent and pin may communicate the hourly full
into the notch to the detent with contacts at a distance.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said William Fletcher Barrett in the Great Seal Patent Office on the
24th April 1882.
WILLIAM FLETCHER BARRETT, of Monkstown, in the County of Dublin, Ireland,
Fellow of the Royal Society of Edinburgh, &c, Professor of Physics in the Royal
College of Science, Stephen's Green, in the City of Dublin, in the same County.
"IMPROVEMENTS IN THE METHOD OF AND MEANS FOR UTILIZING ELECTRIC
CIRCUITS FOR VARIOUS PURPOSES, SUCH AS TELEPHONIC OR TELEGRAPHIC COM-
MUNICATION, CONTROLLING OR SYNCHRONIZING TIME MEASURERS, FIRE OR
BURGLAR ALARM SYSTEMS, OR THE LIKE'
My Invention relates to a method whereby a line used for telegraphic or
telephonic purposes may also be employed for the purpose of keeping clocks or
other time measurers in unison, for giving notice of burglaries or fires, or for other
purposes, and which can be especially adapted to special safes for burglar or fire
detection.
For this purpose I make use of Ritchie's or other system of periodic time control
from a central station, and my Invention consists in adapting to the controlling
and controlled clocks electric contacts, which the clock automatically closes and
opens at certain times. During the day, or such times as may be most convenient,
the controlling and controlled clocks each complete the circuit leading from the
line wire to the telephonic or telegraphic apparatus, except for a short period, say,
ten to thirty seconds, when the telephonic circuit is broken by the clockwork, and
by the same means the line placed in the clock controlling circuit.
The normal clock is allowed then to regulate the controlled clock, and after a
few seconds the line is again thrown to the previous telephonic or telegraphic
circuit. At night time the line is or can be placed by means of the clockwork out
of the telephonic or telegraphic circuit and on to the circuit of the fire or burglar
alarms, the adaptation to one or two forms of which is hereafter described. The
clock control is still carried on during the day as during the night by the automatic
action of the clockwork. There may be also a third or fourth distribution of the
line current for any other purpose, the circuit of which the clock may automatically
complete. Thus the clock may at a given time and for a given period throw into
circuit an electric call for workmen, so that the time of coming to or leaving off
work may be automatically sounded, or it may be used to indicate the performance
of an engine or other machinery at given periods, or record steam or other
pressure.
Further, the line wire may be led to positions accessible to policemen on duty, who,
on the breaking out of a fire or other danger, can unlock a box containing a contact
key, and by opening or closing the circuit transmit a system of preconcerted signals,
and so at once notify the fact to the central station, where the particular locality
will be indicated by the same or a similar arrangement to that used in the day to
indicate the calls by telephone or otherwise.
The clock may also be used as an indicator that a watchman regularly goes his
rounds. For this purpose special addition is made to the clockwork.
And in order that my Invention may be clearly understood and carried into
practical effect, I have annexed the accompanying three Sheets of Drawings. To
Fig. 1, Sheet 1, I now refer.
A is the controlling clock, and B a controlled clock, C, C¹, being the receiving
telephones at the respective stations, and D, D', the transmitters and bells thereof;
E¹, E, E, E, being the earth plates (hereinafter described); F, the indicator
at the controlling station; G, the main battery; G¹, G", telephone batteries. If

page_text: desired, G may be dispensed with, and extra cell power added to G', or vice versa,
but the batteries and mere connecting arrangement form no part of my Invention,
and may be arranged as desired.
On the minute arbour of the controlling clock A I place a notched disc H, and
on the hour arbour a notched disc I; J is a contact spring, as shewn, carrying two
contact pieces; K, K¹, are studs attached to spring L, and so arranged that K' drops
into the notch of the disc H every 60 seconds, and K into the notch of the disc I every
60 minutes, so that before K can drop into its notch K' must just pass the edge of
the "beak" of the notched disc I, thus ensuring both pins dropping at a precise
moment, and after the spring J has been in contact with L¹ for a given time the
revolution of the disc H breaks this control at the moment when the second hand
attached to the disc H arrives at the 60th second. L, L', are two contacts, L going
to the telephone line T, L' to the wire from the battery G to earth E11.
The line wire M from the end of the spring J goes to the controlled clock B.
In this clock, instead of a horizontal " swinging bar" changing (say) the
telephone to the police circuit at the required moment, as mentioned in my
Provisional Specification, I have shewn a spring contact-maker for the purpose,
actuated by a disc with a peripheral cam surface instead of a disc with a cam face,
as before mentioned, but as the mechanism for carrying out the principle of my
Invention can be greatly varied, I do not bind myself to the forms shewn.
The line wire M entering the clock goes to an insulated spring N standing at
right angles to the axis of a notched disc O, mounted on the cannon pinion of the
centre arbour of the minute hand of the clock; and having a pin Q on its circum-
ference depressing a bevelled or curved stud P on and with the spring as the
minute hand goes round, say, every hour; or a pin may be fitted on the spring to
drop into a notch in the disc, as mentioned in my Provisional Specification; or
other means of operating the spring from the disc may be adopted.
When the pin Q comes against the stud P (as shewn) contact is made between a
contact pin carried by the free end of the spring and another insulated contact
piece R, the current then passing off by a wire to the controlling arrangement, such
as that shewn and known to electricians as Ritchie's" or other suitable regulator
may be employed.
The following action takes place when the spring J of the controlling clock A
has made contact with L':-The electro-magnet S attracts its armature S¹, which
causes its lower arm S111 to enter the notch in the disc O when the minute hand is
exactly at the hour, the upper arm S¹¹ having a pin S which drops into the
teeth of an escapement wheel U (without however stopping the pendulum), so
stopping the train of clockwork until the spring J of the controlling clock is
released from contact with L' by the revolution of H. The controlled clock is thus
allowed to start exactly at the hour; hence, as fully explained in Ritchie's Speci-
fication, the controlling clock must have a gaining rate. As the controlling of
electric clocks forms no part of my Invention, the said Specification of British
Letters Patent, No. 333, A.D. 1878, can be referred to for further information
thereon.
During the regulation the current passing through the electro-magnet S goes to
another electro-magnet V, attracting a semaphore W (held off by a retractile
spring, as shewn), which falls at the exact moment that the spring J breaks contact
with L', thus indicating to the attendant the exact time; or the semaphore arm
may strike a bell or gong, and thus give an audible signal,
"
On Sheet 2, Figure 2, shews an alternative arrangement in which the armature
and lever S of the electro-magnet S carries at its end a light vertical arm A³, on
which is pivoted a light counterweighted bar A" carrying a vane of mica or other
light substance, having thereon such words as
on," "off," and arranged to rise
and fall behind an aperture in an opaque disc or plate, as shown by dotted lines.
By this plan the extra magnet V and the electric resistance it introduces can be
dispensed with.
El is the earth connection for the circuit of the controlled clock R.

page_text: The end of the spring N on rising a few moments after the hour is passed
touches a contact piece W¹, from which a wire W₁ goes to an insulated spring ✗
(in place of the before mentioned "swinging bar") and carrying contact points at
its ends. A pin Y is carried by this spring and bears against the periphery of the
cam disc Z, having a half of its surface raised, so that for, say, twelve hours the
disc keeps the spring X in contact with the telephone contact T, as shewn, thereby
placing the telephones C, C', in circuit, or when the lower portion of the disc is in
contact with the pin Y the spring is against the contact F¹ of the fire aların
circuit.
As an example of adapting my Invention, I have shewn a safe X' with a glass
door, having in its interior a U tube X", partly filled with mercury. Into the
open limb of the U tube a wire from the contact F¹ passes. The other limb of the
tube opens by a pin hole aperture to the outer air. E is an earth plate connected
to the U tube. The safe is made air tight, and on shutting the door the pressure
becomes slightly greater than that of the outer air, causing the mercury to be
depressed in the limb 1, and thus kept clear of the wire from F¹. Should the safe
be opened or perforated, the atmospheric equilibrium will be restored, and the
mercury, recovering its level, will complete the circuit with the earth plate Ell, so
that a current will pass through the line wire M, spring J, telephone bell D at the
controlling station, and indicator F. Thus the fact of an outbreak of fire or a
burglary at the office or residence of any subscriber is at once notified to the
attendants at the central telephone exchange, police or fire brigade station, or other
place, the indicator shewing the precise office or house where such has occurred.
Similarly a rise of temperature may be indicated by thermometer, as shewn,
below the safe, or by fusion or expansion of metals, or in any other convenient
manner, but these various devices are not original, and I merely shew them as
indicating some of the purposes to which my Invention can be applied.
In order that one clock may control several lines from one set of contacts, I use
a relay or "distributor" shewn in Fig. 3, Sheet 2 as a plan; Fig. 4, enlarged end
view; Fig. 5 enlarged side view.
As shewn it controls six lines; a, a, are the electro magnets; b the pivoted
armature or iron tongue of the relay; c, c, c, c, c, c, springs to which line wires
are attached; d, d, d, d, d, d, battery contacts; e, e, e, e, e, e, telephone contacts.
As shewn in Fig. 5, the springs c are in contact with contacts e, but when the
tongue of the distributor is attracted, the cross bar f lifts all the springs c
simultaneously, thus putting the lines in contact with the contacts d of the battery
for controlling the six subscribers' clocks.
As a recapitulation of my Invention, I have shown a diagram (Fig. 6.),
demonstrating the apparatus in circuit.
In this Figure g is the controlling clock; h, distributor; i, battery; j, line through
indicator k to telephone l; m, telephone battery; n earth; o, wire from distributor
to battery and earth; p, line wire; q, controlled clock; r, wire through telephone
battery and earth; 8, wire through Ritchie magnet and indicator to earth;
t, burglar alarm circuit and safe; u, u, fire alarms all earthed, as shewn; v, police
key; w, earth for same, arranged so that a policeman can unlock a box in the
street or elsewhere, and transmit signals shewing the locality of a fire, or of a
burglary or other outrage, as before described.
My apparatus could also be used for operating flashing or gun fire signals, or in
fact for a variety of purposes that will suggest themselves to any practical
electrician.
On the controlled clock B, Fig. 1, I have shewn a notched disc Z, with a small
agate pin bearing on its periphery. The disc revolves once a minute; thus when
the pin falls into the notch an independent electric circuit is completed which
attracts the armature of electro magnets actuating simple electric clocks placed in
various stations or parts of a building, which are in consequence always correctly
in unison.
Sheet 3 of the Drawings I have shown such a clock, which, though not

page_text: forming part of my Invention (and therefore not claimed), may still be found
useful as an adjunct thereto.
Fig. 7 is a front view of the clock.
Fig. 8 a side view.
3 is a 60 toothed ratchet wheel connected to or formed with toothed wheel 4,
which gears into toothed wheel 6 driving a pinion actuating the hour wheel 5 on
the centre arbour of the clock, as usual.
A pawl 7 is attached to a spring, as shewn, the end of the spring being carried
by a collar or yoke 8 pivoted at right angles to a light bar 9 carrying the armature
and moving on centres 11. The other end of the bar is furnished with an
adjustable counterweight 10; 12 is another spring pawl in a reversed position on
the other side of the ratchet wheel 3; 13 is the electro magnet. A pin, as shown,
limits the movement of the pawl 7. When the armature is attracted the bar 9 is
lifted, carrying with it the pawl 7, but as soon as the circuit is broken the bar 9
falls by reason of the counterweight 10, thus always advancing the ratchet wheel 3
one tooth every minute, the pawl 12 acting as an escapement. As the wheel 3 is
only advanced by the fall of the counterweight (which is always constant), it does
not interfere with the correct working if the current should be too strong, as in
electric clocks where the fall of the armature directly advances the ratchet.
Having now described the nature of my said Invention, and the best mode
known to me of performing the same, I wish it to be understood that I am aware
that it has been before proposed to utilize an ordinary Post Office telegraph line
for controlling clocks at stations or places on such a line, and therefore I do
not claim such, but what I believe to be novel and original and claim as my
Invention is,--
Firstly. Adapting a series of switches or contacts to periodically controlling and
controlled clocks, so that by the opening or closing of the same two or more
systems of electric circuits (such as telephone, fire, police or alarm) may be
automatically utilized or rendered inoperative from one clock, substantially
as described.
Secondly. The combined apparatus, substantially as described (save such parts
as are bereinbefore disclaimed), no one part being taken separately, but when
arranged and acting in combination, as and for the purposes set forth."
In witness whereof, I, the said William Fletcher Barrett, have hereunto set my
hand and seal, this Twenty second day of April, One thousand eight
hundred and eighty two.
W. F. BARRETT. (L.S.)