Improvements in Automatic Fire Alarms.
Year: 1898

page_text: Date of Application, 15th Mar., 1898-Accepted, 2nd July, 1898
COMPLETE SPECIFICATION.
Improvements in Automatic Fire Alarms.
We, ROBERT JACOB BAKER, of 2207, Cleveland Place, CHARLES BENNETT JONES,
of 2016, East Chase Street, and HENRY OLIVER WISEMAN, of 1517, East Madison
Street, all of Baltimore, in the County of Baltimore and State of Maryland, all
of the United States of America, Gentlemen, 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:
1
This invention relates to an automatic fire alarm for use in warehouses, facto-
ries, hotels, dwellings, &c. and it may be used in conjunction with the local fire-
alarm system or not as desired.
The object of the invention is to provide an automatic alarm which will indi-
cate in what portion of the building fire has been started and at the same time
sound an alarm, and if used in conjunction with the local fire system, will
through suitable mechanism sound an alarm at the fire station and by the alarm
indicate in what district the alarm was turned in.
We accomplish this object by providing a suitable alarm placed in a box of
any dimension and locating in the circuit of the alarm an indicator. Throughout
the several rooms of a house we locate wires leading from the indicator and
normally have the wire in open circuit. We also place thermostats in position
in the wire circuit so that when there is any great amount of heat in the room
they will act to close the circuit and sound the alarm. We also provide auto-
matic means in connection with the box whereby the hinged front will drop to
expose the indicator, and also if the alarm is used in connection with the focal
fire system, the falling front will permit suitable mechanism to operate to sound
an alarm at the fire station.
The invention broadly stated consists of the above arrangement of parts and
of certain details of novel construction of the several parts all of which will be
hereinafter more fully. described and specifically pointed out in the claims.
In order that the invention may be fully understood we will proceed to describe
the same with reference to the accompanying drawings, in which-
Fig. 1 is a front elevation of the automatic alarm with the hinged front down
to disclose the indicator and the several parts of the alarm.
Fig. 2 is a transverse sectional view of the box with the hinged front in closed
position.
Fig. 3 is a detail view of the thermostat used in the wire circuit throughout
the several views.
Fig. 4 is a plan view of the same with the top removed.
Fig. 5 is a detail sectional view of the mechanism used for sounding an alarm
in the engine station.
Fig. 6 is a diagrammatic view of the alarm and the manner of wiring a
building.
In the said drawings, A represents the box or casing of my automatic alarm
which may be of any desired size or configuration as may be found convenient.
It is preferably provided with the hinged front B having the word "fire" placed
[Price 8d.1

page_text: on the inside of the front in luminous paint, and this front is for the purpose
hereinafter stated. The casing is also provided with the hinged door C in one of
the other sides so that the mechanism contained in the box can be easily reached
or inspected.
In the box or casing A, we preferably locate the several parts of the automatic
alarm which is composed of the indicator, the alarm bell, and mechanism for
operating it and the automatic catch for allowing the front to fall. As will be
seen from Fig. 1 the hinged front is in such a position in the box that it will fall
by gravity when the catch is operated and be assisted in its fall by the weight
of the magnets.
The indicator D used in the alarm may be of any desired construction and be
of any size. One wire from each station is passed through a common opening
in the indicator casing and each wire has two branches 1) leading therefrom
which are run to that part of the building which the indicator will designate.
The other wires from each station in the indicator are bunched and connected
with a common wire K¹ which leads to the magnets of the catch.
The alarm is composed of the usual bell E, magnets C¹ and the clapper E
which is carried by the armature F. The arrangement of clapper and armature
which we use in this connection is as follows: The armature F is hinged at one
end to the box or casing as shown at F¹ while its other end Fª is bent downward
and opens and closes a switch so that the aların will be continuously sounded.
The switch consists of the two springs G and G¹ secured at one of their ends in
any desired manner and having their contacting ends in the path of the end F.
It will be understood that one pole Z from the battery is connected with one pole
of the magnets C and the wire leading from the magnets C¹ is connected with
one of the springs while the other spring Gt is connected by a wire G³ with the
magnets of the catch. Thus it will be seen that when the armature is attracted
to the magnets the end F will descend upon the spring G to break the circuit
so that the spring Gʻ will pull the clapper F³ against the bell. Of course as the
end F is moved away the circuit will be completed and the armature drawn down
again. By this means a continuous ringing is kept up.
The automatic catch carried by the hinged front B and which is operated to
allow the front to drop, consists of the magnets H which are in the circuit of
the wire G³, and the armature H' which engages the hook H on top of the box.
The armature H has the springs H³, carried by the pins I, normally bearing
against it to keep it in engagement with the hook. The pins I are carried by
the guard I which holds the magnets in place on the hinged front. I³ represents
a slotted plate which allows for the adjustment of the magnets towards or away
from the armature.
It will be understood that the several parts above described are suitably located
in the box so that when a fire is indicated they will operate. The manner of
connecting the several parts so that they will operate is as follows: One pole of
the battery is connected with one pole of the bell magnets C¹ by the wire Z while
the other wire Z¹ of the battery is carried to the several rooms of the building
as seen in Fig. 6. After leaving the magnets C₁ the circuit passes through the
springs G and G¹ into the magnets H of the catch through the wire G³, and after
leaving the magnets H it passes through the wire K¹, which is connected with
the wires of one pole of the magnets of the several stations of the indicator. The
other wire from each station as above stated is passed through an opening in the
casing which bunches them and each of these wires are provided with two
branches which lead to that part of the building designated by the indicator.
These two wires and battery wire Z run to each portion of the building and at
those points we locate the improved form of thermostat which is shown in Figs. 3
and 4. It consists of the porcelain back L which is secured to the wall or ceiling,
the perforated removable top L' of the same material and the metallic part L³.
This is composed of the iron arms L³ which extend in opposite directions and are
connected by the bow portion L' having the screw L passing through them to

page_text: adjust the tension, and the copper extensions M which when the heat expands
them move into engagement with either branch of the indicator wire. When
this is done it will be seen that the circuit will be complete and an alarm sounded.
It will be seen from the foregoing that we have provided an insulating means in
connection with a thermostat, and that owing to the arrangement there will be
no uninsulated wire exposed, thereby avoiding accidental fires often caused by
the uninsulated portion of the wire coming into contact with an electric wire
which causes a spark. The advantage of the two wires is that if one should
get out of order the other will be ready to complete the circuit.
So far we have only described that part of the invention which is designed for
use in a building and not in conjunction with the local fire system, and it will
be seen from the foregoing description that we have provided an exceedingly
simple and effective arrangement for indicating fire in any part of a building.
It will also be observed that we have described the several parts arranged in what
is known as an open circuit" and it will be understood that an equally effective
result could be obtained in a closed circuit.
If it is desired to use the automatic alarm in connection with the local fire
system we provide the usual clockwork system N on the casing to which the wires
from a battery located in the fire station are connected. In the clockwork we
provide the wheel N¹ having the pins N which are so arranged as to sound the
bell in the engine house, and which is in this circuit, to indicate the number of
the individual box, so that the call can be located at once. The wires leading
from the battery in the engine house terminate in the spring arms N³, N* one
of which, N, is always in contact with the wheel N¹, while arm N is in the path
of the pins N so that when the pins engage the arm the alarm will be sounded.
In order to have this mechanism operate in connection with the fire box, we
connect the hinged front B with the drum O of the clock mechanism by the
chain (so that when the front falls the chain will unwind and allow the side
to drop gradually. In order to hold the clock mechanism when the hinged front
is in position, we provide the spring P, which engages one of the train of wheels
of the clock mechanism so that it cannot unwind to sound the fire alarm.
Qrepresents a switch for throwing out the arm Na to prevent an alarm being
sounded at the engine house when it is desired to inspect the box or try the wires
in the building.
It will be understood that the alarm proper can be used independently of the
local system or in connection therewith, or if preferred a separate and distinct
circuit can be employed to give an alarm in the fire station.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed we declare that what
we claim is:-
1. The combination with the door and the casing provided with the catch, of
an angular bracket having slotted arms in contact with the door, screws through
the slots for adjustably securing the bracket to the door, magnet coils mounted
on the upright arms of the bracket, a bracket I, secured to the door, provided
with openings through which the coils pass and smaller side openings, the arma-
ture, pins projecting back therefrom through the side openings of bracket I, and
springs around the pins, bearing against the armature and the bracket I to hold
the armature normally in engagement with the catch, substantially as described.
2. In an automatic fire alarm, the combination of a box or casing adapted to be
secured to a wall, an alarm bell mounted on a standard secured to the back of
the box or casing, a pair of magnets mounted on a bracket secured to the back
of the casing below the hell, the armature, F, of said magnets, having the down-
wardly-bent end 1, hinged in lugs, F¹, secured to the back of the casing and
carrying a bell clapper, a spring connecting the armature with the standards of
the alarm bell, two contact plates, G and G¹, in the alarm circuit, secured to

page_text: the side of the casing, the former under the latter and in the path of movement
of the end of the armature, substantially as described.
3. A thermostat, comprising an insulated iron bow in contact with the battery
wire and having outwardly-projected arms extending towards the indicator wires,
parallel with the battery wires, bars of different expansibility lying against and
rigidly secured to the inside of said arms and provided with angular toes or con-
tact points adjacent to the indicator wires, and a set screw for adjusting the
spread of the bow, substantially as described.
4. A thermostat, comprising an iron bow in contact with the battery wire but
otherwise insulated and having its arms extending towards the indicator wires,
a set screw through the bow for regulating the amount of spread of the arms, and
copper bars rigidly secured to the inside of the arms and provided with angular
toes or contact points, substantially as described.
5. The thermostat herein described, consisting of the non-conducting back
plate, the edge blocks provided with grooves to receive indicator wires, the iron
bow having spreading arms, secured to the back plate in contact with the battery
wire, the copper bars rigidly secured to the inside of the iron arms and having
contact toes or points, and the set-screw for regulating the spread of the bow,
substantially as described.
Doted this 15th ave of L 1000
WHEATLEY & MACKENZIE,
40, Chancery Lane, London, W.C., Agents.