Improvements in Fire Alarm Annunciators.
Year: 1898

page_text: Date of Application, 7th Oct., 1898-Accepted, 12th Nov., 1898
COMPLETE SPECIFICATION.
Improvements in Fire Alarm Annunciators.
I, CHARLES MAY, of 31, Moray Place, in the City of Dunedin, in the Colony of
New Zealand, Mechanical Electrician, do hereby declare the nature of my inven-
tion for improvements in fire alarm annunciators, and in what manner the same is
to be performed, to be particularly described and ascertained in and by the follow-
ing statement:-
-
The objects of this invention are to detect the presence of fire in the form of
heat, so that when a room or other place gets heated beyond the set temperature,
an alarm is given at the central fire station, or other desired place, and at the
same time an indicator is dropped to a convenient part, such as in front of a
window, so that it can be seen from the outside, setting forth the name or the
number of the room or place where the excess of heat, or fire is, and should the
fire spread from room to room, then other indicators drop, as the heat affects each
place.
This is effected by an apparatus that can be applied to any existing system of
electric fire annunciators and would be made as follows:-
The apparatus consists of a thermostat placed at one or more points in a room,
and capable of being set so as to be electrically connected at any required given
temperature, the wires from these thermostats are so arranged that one is over the
other in several places, and the upper one is furnished with an arrangement for
making an electrical connection on being heated, and consequently lengthened,
thus allowing it to drop down on to the lower wire, and in this manner many
points can be protected from being overheated, at a slight cost.
On any of these electrical connections being made, the wires, being connected
up to a coil, release a cylinder carrying a cord, holding an indicator, several of
which can be arranged conveniently in a box without a bottom, or the like, and
this indicator drops by its own weight and comes into sight showing the over-
heated locality.
At the same time other coils connected up to the common. return wire which is
common to one building or department, draw an armature, releasing a Morse, or
such like machine driven by springs, and trains of wheels, thus sending the special
letter or number of the building to the central station, repeating this signal as
often as needed. When this is attended to, the persons coming to the building
can readily see the locality of the fire without breaking into, or deluging places
not affected, thus avoiding the great amount of unnecessary damage now often
done at present.
Referring to the accompanying drawing: -which is a diagram of the electrical
arrangements and connections. A, A', are thermostats capable of being adjusted to
a degree of heat that is not to be exceeded, without giving an alarm. B, B¹, are
line wires, from A, A¹, respectively. C, is the common return wire for any number
of thermostats.
In the line C, a number of electrical connections may be introduced, such as
shown, consisting of cups furnished with brush points, with or without mercury in

page_text: the cups, these are adjustable as to height, and the line wires are suspended over
these cups, so that rods D, D), may form electrical connection with the cups, which
are marked E, E, and these connections obviously have the same effect as described
for the thermostats.
F, is a coil in circuit with B, C, releasing the drum G, allowing the indicator H,
to drop by gravitation. F¹, and G¹, are a similar device and the indicator H¹, is
shown as released and showing in front of a window, indicating overheating in
room 2, (or any marked room). J, is a detector for readily ascertaining the
strength of the battery K, by pressing the key J', for proving the strength of the
battery as to its working order. L, are coils for attracting the armature L', and
calling the central station by either releasing the transmitting wheel of the instru-
ment M, where the closed system prevails, through the wires O, and P, to the
instrument at the central station, or else by making contact with the point L³,
and sending the alarm through the wires 01, P1, to the place as before mentioned,
where the open circuit prevails. N, and N¹, are ratchet or similar devices for
tightening the wires B and B¹, respectively for the purpose of adjusting the
distance between D, and E, and consequently of adjusting the temperature at
which the alarm is to be given if such temperature is exceeded.
In this invention any suitable materials or sizes may be adopted.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:-
1. In a fire alarm annunciator, the combination with an instrument M, for
transmitting the alarm to the central station, and the apparatus F, F, G, G¹, H, H³,
for displaying the location of a fire in part of a building, of thermostats, A, A¹, and
tension wires arranged for electrical contact, when lengthened by the action of
heat, adjustable as to the amount of heat required for such contact, such as B, B¹,
D, C, E, N, N¹, and indicating the locality of the fire, substantially as described
and explained herein and as shown on the drawings, and for the purposes set forth.
Dated this 4th day of August 1898.
CHARLES MAY,
Patent Office, Chancery Lane, London, W.C.