Improvements in Automatic Code Telegraph Fire Alarm Apparatus.
Year: 1898

page_text: Date of Application, 23rd July, 1898
Complete Specification Left, 24th Apr., 1899-Accepted, 17th June, 1899.
BERIAAL DIECIFICATION.
Improvements in Automatic Code Telegraph Fire Alarm Apparatus.
I, RICHARD PEARSON, of 2, Great St. Helens, in the City of London, Engineer,
do hereby declare the nature of this invention to be as follows:-
This invention relates essentially to the testing of the circuits upon which
fire alarm instruments are installed for the automatic transmission to a central
fire engine (or other) station of a "code" message denoting an alarm of fire and
indicating the precise locality of the outbreak.
It is desirable for many reasons that the working efficiency of such circuits
should be frequently tested and the object of this invention is to enable this test
to be made with such facility from the fire engine station itself that personal
inspection of the installations themselves is unnecessary and the test may be
repeated at such frequent intervals as to ensure the immediate detection of any
accidental or intentional injury to the circuits which would interfere with the
efficiency of the alarm.
The alarm transmitter mechanism is of that kind in which a Morse "code"
wheel is released and set in motion by electro-magnetic mechanism so as to send
through a main circuit a "code" message to a Morse printing instrument at the
fire station. This happens when, by the action under heat of one or other of
numerous thermostats distributed in various parts of the building, the circuit of
the station battery is closed through a releasing magnet in the transmitter apper-
taining to that particular building and with which the thermostats are con-
nected. The thermostats are by preference thermometrical circuit closers of the
kind described in a previous Patent granted to me dated the 21st day of March
1895 No. 5956: those controlling the action of a particular transmitter being
arranged in multiple are upon a normally open circuit carried through the various
parts of the building where the thermostats are situated, such thermostat circuit
terminating at a testing" circuit closer contained in the transmitter instrument.
For testing purposes this circuit closer is operated by an electro-magnet placed
upon a normally open "testing" circuit, and the object of the invention is to so
control the testing circuits of the various installations upon the same mains
leading to the fire station that they shall be automatically closed in succession
in order that each of the several installations shall automatically and successively
transmit to the station a code" message in response to the closure at the station
of the testing circuit of any one installation.
I provide for the closing of the testing circuit of the installation next in order
by the revolution of the "code" wheel of the one first tested and so on in succession
throughout the whose series of installations. With this object the electro-magnets
of the testing electro-magnets of all the installations by which the thermostat circuits
are closed for testing purposes, are connected by one terminal with a testing main run-
ning to the station and capable, when the test is to be made, of being there switched
on to the pole of the station battery to which the outfeed main for the "code"
wheel releasing and propelment magnet is connected. The other terminal of the

page_text: thermostat circuit-closing magnet of the first installation of the series to be
tested is connected to a return test wire also running to the station and capable of
being there connected by a key to the return main for the "code" wheel releasing
and propelment magnets of all the installations, so that when the switch having
been closed, the key is momentarily pressed, the magnet of the testing circuit
closer of the first installation of the series will be excited and the "code" wheel
mechanism will be brought into action in the same way as by the action of a
thermostat itself.
"
In combination with the code transmitter of the first installation of the series
is a testing circuit closer for the return test wire of the next installation of the
series which circuit closer is operated by the "code" wheel of the first installa-
tion and which may be conveniently formed of a pair of contact springs normally
separated and momentarily pressed into contact by a tappet on the wheel which
carries the code wheel. By this means the test circuit of the second installa-
tion is closed, thus determining the action of the code transmitter of that installa-
tion which by means of a similar testing circuit closer in connection with its code
wheel acts in turn and in the same way on the testing circuit of a third installa-
tion, and so on, the action being similarly repeated for each next following
installation in succession.
Dated this 931 dow of Tule 1900
A. M. & WM. CLARK,
Chartered Patent Agents, 53, Chancery Lane, London.
Apparatus,
I, RICHARD PEARSON, of 2, Great St. Helens, in the City of London, Engineer,
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:
This invention relates essentially to the testing of the circuits upon which
automatic fire alarm instruments are installed for the transmission to a central
fire engine (or other) station of a code" message denoting an alarm of fire and
indicating the precise locality at which the fire has broken out.
It is desirable for many reasons that the working efficiency of the alarm
mechanisms and of the circuits through which they are operated should be
frequently tested, and the object of this invention is to enable the whole of the
alarm mechanisms upon the same main circuit to be separately tested by momen-
tarily closing a testing circuit at the fire engine station so that not only is personal
inspection of the several installations unnecessary but the test may be made with
such facility that it may be repeated at such frequent intervals as to ensure the
immediate detection of any accidental or intentional injury to the circuits or
instruments.
The invention is illustrated in the accompanying drawings wherein Figure 1
is a diagram representing on the same main circuit three separate installations
of which the complete mechanism is represented in the first only and the other
two are illustrated diagrammatically the parts being shewn in normal position.
Figure 2 is a similar diagram illustrating in respect of the first installation the
course and effect of the "initial testing" and "code wheel releasing" currents.
Figure 3 is another similar diagram illustrating in respect of the first installation
the course and effect of the "code wheel propelment" current; and in respect

page_text: "
of the first and second installations, the course and effect of the "initial testing
current for the second installation. In Figures 2 and 3 those circuits through
which currents are supposed to be passing are distinguished by the corresponding
wire conductors being shewn as a heavy line.
I, II, III are three separate installations contained in distinct buildings at
any distance apart. I is a fire engine (or other) station at which the alarm of
fire is to be given. Each installation comprises an alarm transmitter mechanism
for the whole building adapted to be set in action by the closure of the circuit of
the electro-magnetic mechanism by which the transmitter is operated, said
closure being brought about by the operation of any one of a number of ther-
mostatic circuit closers T distributed in the various rooms of the building or
(as the case may be) by the operation of the testing mechanism hereafter described.
The alarm transmitter mechanism is of that kind in which, by the revolution
of a "code" wheel A through the agency of electro-magnetic releasing and
propelment mechanism, a code" message, denoting the particular building at
which the installation is located, is sent through a main circuit m m¹, to a Morse
printing instrument M at the fire-station, all the "code" wheels of the several
installations being on the same main circuit m m', but having insulating-segments
differently spaced so as to send distinctive messages. The sending of a message
happens when the circuit of the station battery is closed through a releasing
magnet B of an installation, either by the action under heat of any one of the
thermostatic circuit-closers T, or by the action of a circuit-closing electro-
magnet C.
The thermostatic circuit-closers are by preference U-shaped ther-
mometers having in one limb of the tube contact wires of platinum at which the
circuits are normally broken, which contacts are normally bathed in creosote, the
circuit being completed when mercury contained in the bend of the tube is caused
(by the expansion of the motive fluid contained in the other limb of the tube) to
make electrical connection between the contacts. The thermostats T which
control the action of the transmitter of installation No. 1, for example, are
arranged in multiple arc upon a normally open circuit t t running through the
various rooms wherein the thermostats are situated and terminating at an electro-
magnetic circuit-closer c c¹ contained in the transmitter instrument whereby for
testing purposes the thermostat circuit may be closed by the operation of the
electro-magnet C in connection with a testing" circuit. The circuit-closer c c¹
being at the extremity of the circuit the whole circuit will be tested up to
66
the very terminals of the thermostats T.
The object of the invention being to enable the whole of the various installa-
tions I, II, III, etc., upon the same main circuit, to be tested separately in
response to the single momentary closure of one "testing" circuit at the station,
I provide means whereby the "testing" circuits of the installations shall be auto-
matically closed in succession, in order that each of the installations shall auto-
matically and separately transmit to the station its distinctive "code" message.
With this object all the electro-magnets C (by which the thermostat circuits of
the several installations are closed for "testing" purposes) are connected by one
terminal with a "testing" main D running to the station F and capable, when
the test is to be made, of being there connected by a switch d to the outfeed
main E through which current is supplied to the "code" wheel releasing magnet B
and the "code" wheel propelment magnet H. The other terminal of the
magnet C of the installation No. I is connected to a return test wire d' also
running to the station F and capable of being there connected by a key to
the return main E', common to the magnets B H of all the installations. When a
test is to he made the switch d is first closed and the key is momentarily
pressed, whereupon the magnet C of the installation No. 1 will be excited and
will attract its armature e which forms one member of the electro-magnetic circuit-
closer, whereupon the circuit will be closed at c c¹ first through the releasing
magnet B and then through the propelment magnet H of the "code" wheel
mechanism which will thus be brought into action in the same way as though the

page_text: circuit were closed by the action of a thermostat T. The arrows 1 indicate the
path of the initial testing current for installation No. 1; the arrows 2 the current
for releasing the "code" wheel, the arrows 3 the "code" wheel propelment
current; the arrows 4 the initial testing current for installation No. 11; and
the arrows 5 the current in tlie alarm circuit.
The construction and operation of the propelment mechanism are as follows:-
I is a lever which carries a driving pawl that engages with, and propels, a
ratchet wheel J fast on the same axis with, but insulated from, the code trans-
mitting wheel A. An arm J¹ fixed to this ratchet wheel has a rearwardly project-
ing lug at its extremity which is normally engaged by the pin 1 of the escape-
ment, carried by the armature of the releasing magnet B, and in this position
a contact piece I carried by lever I is held (by the engagement of pawl with
wheel J) out of contact with a contact piece carried by the armature h of the
propelment magnet H, the connections of the coil of magnet H and of the
parts II, hh with the outfeed and return mains E E¹, being such (as shewn)
that by the release of the arm J the contact piece I will be allowed to fall on to
the contact thus closing the circuit through coil H (as shewn by arrows 3)
which being excited attracts its armature whereupon (by the circuit becoming
broken between h¹ and I in consequence of the momentum acquired by the
latter) the armature falls and is again attracted, and so on, thereby causing the
pawl to revolve the wheel J tooth by tooth and with it the "code" wheel A
until the arm J is again arrested by the escapement. Should the armature of
magnet B then still be attracted, this arrest will be effected by the pin 62.
In combination with the transmitter of each installation of the series is a
circuit-closer whereby the operation of such transmitter in response to a
testing current will automatically bring about the closure of the testing
circuit of the next installation of the series. This circuit-closer may be con-
veniently formed of a pair of contact springs K K¹, which are normally separated
and are momentarily pressed into contact by a tappet on the ratchet wheel J,
the connections being such that when the springs K K are pressed into contact
by the wheel J of installation No. I the magnet C of installation No. II will be
connected to the return main E', with the effect that this magnet being excited
(by the current indicated by arrows 4) the thermostat circuit t of installation
No. II is closed and the code transmitter of that installation is set in operation and
transmits its distinctive message to the station. Its code wheel consequently acts
in turn and in the same way on the testing circuit of the installation No. III, and
so on, the action being similarly repeated for each next following installation in
succession. This closure of the testing circuits of the several installations in
succession only happens, however, when the switch is closed for testing pur-
poses, so that, the testing main 1) being normally open, the individual operation
of any one installation by the action of fire on a thermostatic circuit closer will
not entail the operation of the other installations and so cause confusion as to the
locality of the fire.
The following is a concise description of the operation. When a test is to be
made, the switch d at the fire engine station is closed and the key is momentarily
depressed. The current then passing through circuit No. I energizes magnet C,
whose armature, being attracted, closes at ce¹ the circuit for current No. 2, which
current at once energizes magnet B whose armature being attracted, removes
the stop out of the path of the rearwardly projecting lug at the end of the
arm J. The wheel J being thus free to rotate, the lever I (which remained held
up by the engagement of the pawl & with a tooth of wheel J when J¹ was stopped
by at the previous operation, this being the position shewn in the drawings)
falls by its own weight until the contact piece I rests upon the contact piece h¹.
Current No. 3 thereupon passes by way of lever I and the armature lever of
magnet H. This magnet being excited attracts its armature h and raises lever I
so suddenly that the momentum of said lever continues to carry it upwards after
the movement of armature h is arrested. Two effects are produced namely

page_text: on;
(1) Contact at I, ¹, is broken; the magnet H ceases to be energized, and the
armature h falls; (2) the pawl is made to engage with a fresh (i. e. higher)
tooth of wheel J, and the lever then descends until contact is again established
at 1,, whereupon lever I is again thrown up, breaking contact again, and so
the repeated oscillation of lever I continuing until wheel J has performed
a complete revolution, whereupon it is stopped by lug on arm J' coming against
stop 6.
Should the key d³ (instead of being depressed momentarily) have been
held down up to this time so that current continues to pass the arm J' will
be arrested by the stop which is then presented in the path of j, by reason of
the continued attraction of the armature b. When key is finally released,
armature brises and b¹ is substituted for b².
The revolution of "code" wheel A and of the wheel J (besides causing the
"code" signal of installation No. I to be sent through circuit 5) has the further
effect of closing the initial testing circuit of installation No. 11. This happens
when the tappet on wheel J of installation No. I causes spring K to make
contact with spring K¹ so that circuit No. 4 is closed through magnet C of installa-
tion No. II, in whose apparatus the cycle of operations described is repeated
whereby installation No. III is actuated, and so on.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, I declare that what
I claim is:
1. The combination with an automatic fire alarm transmitter such as described,
adapted to be set in operation by the closure of a normally open circuit upon
which thermostatic circuit-closers are arranged in multiple arc, of an electro-
magnetically operated circuit closer for such thermostat circuit, the electro-magnet
coil being placed in a testing circuit capable of being connected for testing pur-
poses with the battery at the station so as to enable the operation of the trans-
mitter to be determined from a distance as described.
2. The combination with a series of automatic fire-alarmı transmitting installa-
tions on the same main circuit, cach adapted to be set in operation by the closure
of a normally open circuit upon which thermostatic circuit-closers are arranged
in multiple arc as described and each adapted to transmit a distinctive message,
of electro-magnetically operated circuit-closers one for each such thermostat
circuit, capable when excited of closing the thermostat circuit and thereby deter-
mining the operation of the transmitter to which it corresponds and of normally
open testing circuits for each installation and a circuit-closer for each such testing
circuit, each such testing circuit-closer being so combined with the transmitter
of the installation of the series preceding that to whose testing circuit it apper-
tains, that the operation of the transmitter wheel of each installation will deter-
mine in turn the closure of the testing circuit of the next succeeding installation
substantially as specified.
Noted this 94th day of April 1899