IMPROVEMENTS IN DISTRICT AND FIRE ALARM TELEGRAPHS
Year: 1874

page_text: LETTERS PATENT to John Henry Guest, of Brooklyn, in the State of
New York, United States of America, for the Invention of "Iм-
Scaled the 7th July 1874, and dated the 8th April 1874.
PROVISIONAL SPECIFICATION left by the said John Henry Guest
at the Office of the Commissioners of Patents, with his Petition,
on the 8th April 1874.
I, JOHN HENRY GUEST, of Brooklyn; in the State of New York,
5 United States of America, do hereby declare tlic nature of the said
Invention for "IMPROVEMENTS IN DISTRICT AND FIRE ALARM TELEGRAPHS,"
to be as follows:―
Several district aláŕm telegraph instruments have been employed in
one telegraph 'circuit, and on depressing a lever of one of tlie instru-

page_text: ments pulsations of electricity are sent that indicate at a central
receiving station the location from which the signal is sent and what is
indicated, such as "police," "fire,” 'messenger."
The present Invention is designed to indicate at a central station the
location of a fire without interfering with the district alarm instruments
connected in the same line.
The first part of this Invention relates to a thermostat. I have dis-
covered that the material known as hard rubber is especially available for
a thermostat because its expansion is very regular, and it is not influenced
by changes of moisture in the atmosphere.
I employ a rod or tube of this to release clock mechanism and ring
a bell or to open or close a telegraphic circuit by its expansion, and thus
indicate on a signal instrument the excess of heat.
In some conditions it is preferable to employ a thermostat made of a
mercurial bulb with a tube of such a length that beyond a certain tem-
perature the mercury is confined and breaks the bulb, liberating a
peculiar circuit-closing spring that gives the signal at the distant station>
or else liberating clock mechanism that gives that signal cither through
the ringing of a bell or the closing of a circuit.
The second part of this Invention relates to a peculiar mechanism
operated by the expansion of the thermostat that liberates a circuit-
closing wheel, the revolution of which denotes at the central station the
number or other signal by the pulsations sent.
The third feature of this Invention relates to the arrangements of the
electric circuits that contain the district telegraph instrument of the
general character shown in the Patents aforesaid and the fire signal
herein named, such arrangement of the circuit having special reference
to the transmission of fire signal without interfering with the district
signal boxes, and so that in case the line is cut or broken at one point
still the instruments in the line, both fire and district alarm, will be
operative at the central station.
The fourth part of this Invention relates to an annunciator operated
by electricity and brought into action by the thermostat so as to indicate
which thermostat is acted upon. This is especially available in a hotel

page_text: in case of fire or excess of heat in any one place, and the circuits arc
so arranged when desired that the location of such excess of heat is
signalled to a central station by the number of pulsations.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Henry Guest in the Great Seal Patent Office
on the 2nd October 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
HENRY GUEST, of Brooklyn, in the State of New York, United States of
America, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eighth day of April, in the year of our Lord
One thousand eight hundred and seventy-four, in the thirty-seventh
year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto me, the said John Henry Guest, Her special licence that I,
the said John Henry Guest, my executors, administrators, and assigns,
or such others as I, the said John Henry Guest, my executors, admini-
strators, and assigns, should at any time agree with, and no others,
from time to time and at all times thereafter during the term therein
expressed should and lawfully might make, use, exercise, and vend,
within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN DISTRICT
AND FIRE ALARM TELEGRAPHS," upon the condition (amongst others) that
I, the said John Henry Guest, my exccutors or administrators, by an
instrument in writing under my, or their, or one of their hands and
scals, should particularly describe and ascertain the nature of the said
Invention, and in what manner the same was to be performed, and
cause the same to be filed in the Great Seal Patent Office within six
calendar months next and immediately after the date of the said
Letters Patent.
NOW KNOW YE, that I, the said John Henry Guest, do hereby declare
the nature of my said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the
following statement, reference being made to the Drawings hereunto

page_text: say) :—
District and alarm télégraphi apparatus have been employed in which
the machines are all in one telegraph circuit, and on depressing a lever
of one of the instruments pulsations of electricity are sent that indicate
at a central receiving station the location from which the signal is sent
and what is indicated, such as "police," "fire," "messenger," &c.
The present Invention is designed to indicate at a central station the
location of a fire without interfering with the district alarm instruments
connected in the same line.
The first part of this improvement relates to a thermostat. I have
discovered that the material known as hard rubber is especially available
for a thermostat because its expansion is very regular, and it is not
influenced by changes of moisture in the atmosphere.
I employ a rod or tube of this material to release clock incchanism 1
and ring a bell, or to open and close a telegraphic circuit by its
expansion; and thus indicate on a signal instrument the excess of heat.
This thermostat is also available as a thermometer.
In some conditions it is preferable to employ a thermostat made of a
mercurial bulb with a tube of such length that beyond a certain tem-
perature the mercury is confined and breaks the bulb, liberating a
peculiar circuit-closing spring, that gives the signal at the distant station
or clse liberating clock mechanism that gives that sigmal either through
the ringing of a bell or the closing of a circuit.
In some cases I employ a thermostat made as a convex disk of hard a
rubber, which acts by expansion for the purposes above set forth.
The second part of this Invention relates to a peculiar mechanisni
operated by the expansion of the thermostat that liberates à circuit-
closing wheel, the revolution of which denotes at the central station the
number or other signal by the pulsations sent.
The third feature of this Invention relates to the arrangement of the
electric circuits that contain the district telegraph instruments of the
general character aforesaid and the fire signal herein namiéd, such
arrangement of the circuits having special reference to the transmission
of fire signals without interfering with the district signal boxes, and so
that in case the line is cut or broken at one point still the instruments.

page_text: in the line, both fire and district alarm, will be operative at the central
station.
The fourth part of this improvement relates to an annunciator
operated by electricity and brought into action by the thermostat so as
to indicate which thermostat is acted upon. This is especially available
in a hotel in case of fire or excess of heat in any one place, and the
circuits are so arranged when desired that the location of such excess of
heat is signalled to a central station by the number of pulsations.
In the Drawing Fig. 1 is an elevation and Fig. 2 is a side view of two
instruments in which the expansion of the rubber rod or tube a is made
to act through the levers b and c to open or close the circuit connections.
In Fig. 1 these circuit connections will be closed between 2 and 3 by
the expansion of the rod a by increase of temperature. If the parts are
in the form indicated by dotted lines the expansion of a will separate 2
and 3 and break the circuit. The screw adjustment 6' at the end of the
rubber rod a regulates the position of the parts so that the circuit is
opened or closed when a defined temperature is reached.
it
In Fig. 2 and Fig. 2 the hooked end 5 of the lever c prevents the
spring arm e moving towards the contact block 6 until the hooked
end 5 is forced upwardly from behind the spring arm e, liberating the
same so that it immediately closes the circuit through 8 and 9, and
breaks it between 10 and 8.
•
In Figs. 8, 9, and 21 the thermostat is represented in connection with
clock mechanism. In these Figures the expansion rod or tube a is of
hard rubber or equivalent material, and at one end is an adjusting
screw b. To this may be applied a hand b³ and a dial c³ to indicate the
temperature at which the expansion of the rod a will become operative
on the indicating mechanism, for if the screw is turned back the tem-
perature will have to be increased in order that the expansion may
sufficiently lengthen the rod to cause it to move the parts with which it
is connected.
In Fig. 22 the expansion hard rubber rod or tube a is shown without
clock mechanism and as adapted to use as a thermometer, the rod a
acting through the lever bupon the lever hand 63, which latter indicates
the number of degrees of temperature upon the dial c³.
In Fig. 23 the thermostat is represented as a glass tube containing
mercury. The mercurial bulb f³ is in a fixed position, and the circuit-

page_text: closing spring 7 presses against a projection at the unsupported end of
such bulb, so that when the bulb breaks by the expansion of the mercury
the circuit-closing spring 3 passes from the plate g' to the insulated
plate 95, and in so doing changes a circuit connection to give an alarm
by a bell and magnet or similar device. When the spring gå in the
normal position is a stop for clock mechanism the same will be liberated
and give the alarm when the bulb is broken by excess of heat.
In Fig. 20 the thermostat is represented as made of a thin metal plate
secured to a strip of hard rubber. One end of this double strip or plate
is firmly connected to the post .h, and the other end in the normal
position presses again the binding screw h³. If the temperature
increases the unequal expansion of the hard rubber and metal causes the
double plate to bend, and the moving end is brought in contact with
the binding screw which closes the circuit h, h, and breaks that
of h', h³.
In Fig. 15 the thermostat is made of a convex disk of hard rubber
or equivalent material. This device is hereafter referred to.
The manner in which the above-described instruments can be used in
circuits cither alone or in connection with district alarm telegraph instru-
ments will now be explained.
"
In the diagrams the parts marked B represent the battery; G, the
ground connection; 1, the district telegraph alarm instrument operated
by hand to indicate " messenger," 'police," or other call; T, the
thermostat like that in Fig. 1, and where an annunciator is represented
it is marked A; × is the main circuit. The annunciator may be of any
desired character, but it is shown with a swinging tag (2) on a bent lever,
which is moved up by hand, but it swings down when the armature m is
attracted by the magnet E or E' and liberates the arm of the swinging
tag. L represents an alarm bell rung by the electro-magnet E or by
clockwork liberated by that magnet E.
The number of alarm instruments I, thermostats T, annunciators A,
and bells L, may be increased to any desired extent, the circuit wires
being extended to include them. The number shown in the diagrams is
limited for greater clearness.
At the central station the battery B is located, also one or more
receiving or indicating instruments 8 or s', which may be dials, Morse

page_text: registers, bells, or other devices, adopted specially to indicate numbers
dots, thus
standing for 1 2 3, and so on, the attendant.
being provided with a table indicating the location of the instrument
that is fitted to send that number and what this signal signifies, and a
prearranged arbitrary mark or signal may be employed to denote
whether the signal sent is from a thermostat, or district, or other alarm
instrument.
The electric circuits may be composed entirely of insulated wires or
partially of ground connections, or of two insulated wire circuits, as
hereafter explained and illustrated.
In the diagram, Fig. 3, the thermostat T is in a metallic circuit.
adapted to a hotel. The switch or press button at N is employed for the
usual call to a room, and operates to close the circuit, ring the bell L,
and drop the annunciator tag A. If the thermostat expands by excess of.
heat it closes the circuit automatically, producing the same call, and the
bell L will continue to ring while the circuit is closed, the act of moving
the armature breaking the circuit to the magnet E as heretofore usual in
alarms.
In Fig. 4 the thermostat T is shown in the normal position as closing
the circuit, and as breaking it when the rod A expands, thereby striking.
the bell as the armature recedes.
Fig. 5 shows a district alarm instrument I in the circuit adapted to
give a signal by taps on the bell L at the central office when the instru-
ment I is operated or started by hand, but any other indicator may be
used in place of the bell L. The thermostat T is in the main line x, and
closes the same in the usual manner. When the rod A. expands the
circuit is broken, which demagnetizes E, the armature m falls and
closes the circuit × at 10, the armature is attracted and the circuit again
broken at 10. Thus the thermostat causes the bell L to continue to ring
until the circuit at T is again closed. If the instrument is used with a
switch or press button at N to close the circuit at a room then the:
annunciator A will be operated, the magnet E' being charged by closing
the circuit at N.
By making the connections as shown the continued expansion of the
thermostat will close the circuit through 11 and E¹ to the battery, and in
the fall of the annunciator tag 2 that circuit might be broken at 12, but
if the connection remained as indicated by dotted lines, the magnets E¹

page_text: and E will be operated alternately if the magnet E' offers more resistance
than the magnet E.
t.
Fig. 6 illustrates a circuit with a number of district alarm instru-
ments I, and shows how a main circuit × can be connected by a wire to a
thermostat T at any point, either near or remote, and the signal given by
short circuiting the current through the ground to the instrument S' at
the central station, if the thermostat closes that branch circuit, to the
ground.
Fig. 7 illustrates how two or more thermostats Ț can be connected
from the main circuit ✗ by branch wires to a magnet E, the armature
of which forms a stop for clockwork, so that when the thermostat closes
the branch circuit the armature m is attracted and held by a spring catch
and the clockwork will ring an alarm bell. The circuit to E will be
closed by the expansion of either thermostat, and short circuit the current
through E without breaking the continuity of the main circuit .
The thermostat mechanism shown in Figs. 8, 9, and 10 consists of a
circuit wheel k, insulated circuit-closing springs 22 and 23, an actuating
spring with an arm i upon the arbor ² of the spring barrel or other
arbor, so that when this arm is turned back by a key applied to the
arbor the spring is partly wound and held by the arm or dog c. When
the arm c is swung back by the expansion of the rod a acting through
the lever the arm i is liberated, and the spring turns that arm and the
wheel k. An escapement and pendulum or vibrator limits the
rapidity of movement so that the circuit whcel makes and breaks
the electric circuit to give the required indicating pulsations to repre-
sent numbers, letters, or other characters at the central station. This
circuit wheel is made with notches in its periphery or with conducting
and non-conducting material, so that as it revolves it makes and breaks
contact with the ends of the springs 22 and 23, and produces pulsations
in the circuit, and the notches are positioned to give the prearranged
signal to indicate at the central office what thermostat instrument is
operative.
111,
In Fig. 11 the circuits are represented with special reference to the
instrument shown in Figs. 8, 9, and 10. The wheel / has the notches
to give the signals, and the springs 22 and 23 are insulated. The line
wires connect with 22, and the body of the clockwork and the
springs 23 are connected to earth G. The spring 22 in the normal

page_text: position is in contact with k, but the spring 23 is not, hence the line a
is complete through 22 and k and the frame of the machine, and any
number of these instruments can be placed in the circuit together with
the district instruments I. If the wheel is turned in consequence of
the thermostat, liberating the clockwork that revolves the same, tho
springs 22 and 23, when both resting simultaneously on the edge of the
wheel k, short circuit the current to earth, producing pulsations that are
received and recorded on the instrument s' at the central station, hence
the operation of the thermostats would not be prevented if the line was
cut or broken at any one place, as the earth connection is in the middle
of the battery, and by use of a switch at 15 the instrument I could be
brought into action even with the main line cut or broken, the circuit
passing through the earth and the signal being received at S'.
12
In Fig. 12 the circuit wheel / is revolved as before; but the escape-
ment vibrator 2 is held by a lever arm c until the expansion of the hard
rubber rod a acting upon the lever 6 and arm c moves the latter out
of the way of the pin i upon and allows the escapement to vibrate and
the pulsations to be sent through 22 and 23 as before mentioned. The
arm k forms a stop to the winding arbor so as to determine the point at
which the wheel k will be arrested, and in Fig. 14 this stop k is repre-
sented as in contact with spring 34, extending from the base of the
spring circuit closer 22, so that the circuit will be reliably closed through
this spring 34 and the clockwork when the machine is wound and at rest,
but this arm * separates from 34 when the clockwork commences to
move, so that the wheel / will give the correct pulsations and signals.
This connection prevents risk of the circuit being broken by. oil or dirt
upon the arbor of the wheel k, and it may be used with either of the
instruments in which this wheel k is employed. Under some circum-
stances a rod of hard rubber or similar material cannot be conveniently
employed. I obtain similar results by using a conical disk of hard
rubber or similar material sustained at its edges by a ring and acting in
the middle upon the thermostatic alarm.
Fig. 15 is a section of the said disk and alarm mechanism, and Fig. 13
is a plan of the alarm mechanism.
The disk of hard rubber or non-metallic solid or other expansible
material is sustained at its edges in a ring v₁, and receives an adjusting
screw wat or near the center. This presses upon the spring lever 36,

page_text: and prevents the spring 37 thereof moving said lever, but when the
convex disk v expands the center thereof and the screw w are raised and
the spring 37 acts upon the lever 36 to press down one end of the
lever 39 and raise the other end, liberating the stop finger i of the
vibrator or escapement, and allowing the clockwork to run and revolve
the circuit wheel k or give a signal or alarm in any other convenient
manner. By adjusting the screw w the thermostatic alarm can be made
to operate at any desired temperature.
Fig. 16 represents circuit connections with thermostats and a Morse
receiver at z, the object being to operate the relay magnet R of the main
circuit x at the central station by either circuit wheel, and by relay
open and close the local circuit of the battery L' and indicate the signal
upon the receiver z. If however the main line circuit x is broken or
cut and the pulsations from either thermostat instrument pass through
the earth the second relay magnet R¹ will be operated. The armature
of R' is also connected in the local circuit, so that when the switch 15.
is changed the relay R¹ will operate the receiver z and make the same
character of mark as is made by the relay R. By this arrangement the
relay R can be used with district alarm, or with the thermostat instru-
ments in a metallic circuit and operate a Morse receiver, and when the
current is sent through the earth in consequence of the main circuit x
being broken at any one point the circuit will be closed by 22 and 23
resting simultaneously on k, and hence the relay R' is arranged to close
the local circuit on the front stroke of the armature in order that the
same character of mark may be made in the receiver z by the local
circuit through R' as when the local is closed by the relay R in the back
stroke.
In Fig. 17 a metallic circuit is shown that may contain district alarm
instruments, a battery, and a sounder E, and this sounder will usually be
charged, and if the main line circuit is broken the sounder will indicate:
the same by the armature falling back, and the sounder may be
connected as in Fig. 5 to ring an alarm when the main line circuit is
broken. Into this main line circuit one or more branches may be
connected as represented running through one or more thermostat
alarms as at k, k, k. I have represented two branch circuits with three
thermostats in each and an earth connection, by which I illustrate
branches to two buildings and three thermostats in each. When either
of the thermostats operates the signal is received at the call or sounder E

page_text: in the branch circuit at the central station leading to the earth. It is
generally preferable to place a battery in this earth branch. By this
arrangement the thermostat will give a signal without interfering
with the circuit in which the district alarm instruments are placed.
In Fig. 18 a similar arrangement of circuits is illustrated to that in
Fig. 17 except that the thermostats are of the character shown in Fig. 1,
and in order to indicate at the receiving station the number of the place,
from which the signal is sent I lead the ground connection first
through a magnet that liberates the clockwork that revolves the circuit
wheel k.
In Fig. 19 the main circuit a contains district alarm or similar
instruments I operated by the battery B, and in the circuit is the relay
magnet R operating the local circuit and register z. From the main
linex there are branch circuits and thermostats T or k, as in Figs. 17
or 18, and these connect through the ground or a separate line to the
relay R¹ and battery B', and the relay R' operates the local circuit
and receiving instrument 2¹, which of course will only respond to the
thermostats. At P, S, is a fire patrol station or engine house with a
receiving or indicating instrument 23, and there is a battery in this
circuit, and it is opened or closed by circuit closing points at the
armature of the receiving instrument z¹, or by a second set of circuit
closing points on R¹, or the instruments 21 and 22 may be in one circuit,
thereby the fire alarm indication is given at the engine house or patrol
station as well as at the central station.

page_text: Fifteenth. A relay magnet in the main circuit and a relay magnet in
the earth circuit at the central station, and a registering instrument in a
local circuit connected with both the relays, in combination with a
thermostat break wheel in a branch circuit from the main line,
substantially as set forth.
Sixteenth. A circuit containing district alarm telegraph instruments,
battery and indicating instrument at the central station, and thermostat
alarm instruments in branch circuits from the main circuit, in com-
bination with a relay circuit to an indicator at the firc-patrol station
operated by the thermostats and not by the district alarm instrument,
substantially as set forth.
In witness whereof, I, the said John Henry Guest, have hereunto
sot my hand and coal this Ninth day of Can
AT 1074
J. H. GUEST. (L.S.)
5 Witnesses,
CHA³. H. SMITH, 121, Nassau St., New York,
GEORGE SERRELL,
"
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