Improved Automatic Fire Alarm.
Year: 1888

page_text: Improved Automatic Fire Alarm.
I, HENRY HARINGton Leigh, Fel. Inst. P.A., Assoc. M. Inst. C.E., practising as
Phillips & Leigh, of No. 22, Southampton Buildings, Chancery Lane, in the County
of Middlesex, Engineer and Patent Agent, do hereby declare the nature of this inven-
tion as the same has been communicated to me from abroad by Carl Guentner, of
Vienna, 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 to improved apparatus for automatically detecting and
indicating the position of an outbreak of fire; and consists in the combination of a
cord or cords adapted to be readily severed by fire with a weight suspended from
the said cord over an electrical contact forming part of the circuit of an electric
alarm.
In order that my invention, and the means by which the same can be carried into
practical effect, may be thoroughly understood, I will now describe the same in detail,
referring in so doing to the accompanying figures which are to be taken as part of this
specification and read therewith.
Fig. 1 is a diagrammatic sectional elevation illustrating the application of my
invention.
Fig. 2 is a sectional detail elevation.
A, B, C represent three rooms. Through each room is led a cord S¹, S², S³, starting
from a fixed point in each. The cord may be of any material provided that it is
strong enough to support the weight (the function of which is described further on),
and is at the same time incapable of resisting the destructive action of flame.
Fig. 1 illustrates the cords as starting from fixed points under or above the floors,
led up or along the walls and along the ceilings or under the floors; but they may be
led in any direction according to the risks of the particular case. The cords are led
over pulleys or other equivalent devices and their opposite ends carry the respective
weights G, G, G, which hang over the respective contacts T1, T2, T3, within tubular
guides H, H, H, which serve also to protect the contacts from injury. The weights
are sufficiently heavy to keep the cords tight, and to depress the contacts when the
former are severed.

page_text: The contacts are of any convenient construction adapted to be closed by the impact
of the falling weights. They may be fixed in any convenient or suitable position, and
are electrically connected with the alarm.
The operation of the invention is as follows.
When a fire breaks out the cord next it is severed. Its weight falls, and closing
the circuit controlled by it sounds the alarm, thereby not only apprising the watchman
on duty of the fact that a fire has broken out but also indicating the particular portion
of the premises under his charge where the fire is; so that as soon as the watchman
has noted which weight has fallen, no time is lost in ascertaining the exact
position of the fire, and the latter can be extinguished before it has had time to
spread.
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 :-
In automatic fire alarm apparatus, the combination of inflammable cords, weights
supported therefrom within guides and over electrical contacts forming part of electrical
alarm circuits, substantially as set forth.