An Improved Fire Detector and Alarm.
Year: 1889

page_text: Date of Application, 30th May, 1889-Accepted, 30th Nov., 1889
COMPLETE SPECIFICATION.
An Improved Fire Detector and Alarm.
I, WILLIAM EDWARD SMITH, of the Langham Hotel, Portland Place, in the County
of Middlesex, Engineer, do hereby declare the nature of this invention and in what
manner the same is to be perforined, to be particularly described and ascertained
in and by the following statement :-
My invention has for its object the detection or discovery of fire in a building or
buildings or premises of any kind whether public or private, or in rooms or
apartments in such premises or in ships or railway-trains, or in collieries or other
places.
My improved fire detector and alarm is actuated solely by pneumatic agency, no
electric apparatus or other communicating power being required.
My improved apparatus comprises a box or chamber of any suitable form which is
hermetically sealed and which I call the "air-chamber." I make the air-chambers
either of brass, copper, gun-metal, tin or any other suitable metal or material, which
may be a good conductor of heat or otherwise. The said sealed box or air chamber
has a pipe attached to it of any desired length. This pipe may be of very small
diameter and similar to the piping used for gas fittings. The said pipe and the afore-
said air chamber combined form the air storage.
The end of the pipe, remote from the air chamber is sealed to .the outward air, a
sufficient quantity however having been previously blown or forced in to obtain the
necessary pressure and ensure a proper amount of expansion, but the end terminates
in one or more flexible discs or diaphragms of India-rubber, thin metal or other elastic
material which dilate by the expansion of the enclosed air. And the motion due to the
dilation of these discs actuates a tell-tale apparatus of any suitable construction
comprising a system of levers and weights with automatic labels for indicating the
exact locality of the fire and also liberating or setting in motion the clockwork or
other movement of an alarm bell or other signal.
In the accompanying drawing
Figure 1 is a vertical section of a building fitted with my improved apparatus.
Figure 2 is a front elevation of the indicator portion of my apparatus, drawn to
an enlarged scale.
Figure 3 is a front elevation, partly in vertical section, drawn to a still further
enlarged scale, showing details of construction.
A A are the air-chambers, one of which is fitted in or beneath the ceiling of each of
the rooms of the building. B is the indicator or tell-tale portion of the apparatus.
C is the alarm-bell.
The air-chambers A are connected respectively by pipes a with indicating devices b
constructed as follows, viz. :-The pipe a terminates in a small chamber c provided
with a flexible disc or diaphragm c', upon which rests a metal plate or piece d
pivoted at d¹ to a bracket d' attached to the box or case e, in or upon which bracket
the said chamber c is supported. The plate d is provided with a bent wire or catch d³
adapted to engage with and support an arm or label f pivoted at f' on a pin or stud
attached to the box or case e. 9 is a rod or spindle supported in brackets h attached
to the said box or case; this rod or spindle is provided with arms g¹ which
extend beneath the arms or labels frespectively. The said rod g is also provided
with an arm g coupled by means of a rod or link j to a catch-lever k.
pivoted at to the box or case e, and is acted upon by a spring 1. A weighted
arm m is pivoted at m¹ to the said box or case, and is arranged to fall, when released
as hereinafter explained, upon a spring n attached at one end to the box or case e and
provided with an arm or projection n' coupled, by means of a rod or link o, to a spring
catch P attached at one end to the box or case e.
This lever is

page_text: 9 is a cylinder or chamber attached to the box or case e and provided with a piston
or plunger q arranged to be acted upon by a weighted arm pivoted at to the box
or case e. The cylinder q is connected by a pipe s with any well-known device which,
when actuated by compressed air, will cause or permit the action of the bell ().
To set or adjust the apparatus, the weighted armis m and r are raised, and the
catches and p caused to engage therewith. The arms or labels fare also raised and
the catches d³ caused to engage with the said labels. The parts then occupy
the positions indicated in Figure 2 and the apparatus is ready for indicating the
presence of fire in any part of the building.
The operation of the apparatus is as follows, that is to say :-If a fire takes place
in either of the rooms of the building, a very small degree of heat imparted to the air-
chamber will cause the expansion of the air therein, and this expansion will
immediately extend through the length of piping till it acts upon the flexible disc or
diaphragm cl of the corresponding indicator, thereby raising the catch d³ and releasing
the label which falls into such a position that it can be seen through an aperture or
window in the lid or cover of the box or case e, and will thus at once indicate the
locality of the fire. The label f falls upon one of the arms g' and thereby turns the
rod or spindle g about its axis, thus disengaging the catch k from the weighted
This lever then falls upon the spring n and thereby disengages the catch p
from the weighted arm r, which falls upon the piston or plunger q¹ and thereby
compresses the air in the cylinder 9 so that the alarm-bell is set ringing.
lever m.
The tell-tale apparatus is preferably provided with means for adjusting it so that it
can be regulated to act at any required degree of temperature. This can be readily
effected, in the apparatus shown, by varying the length of the catches d³, so that
the distance through which they must be raised by the diaphragms c', in order to
release the labels f, will be increased or diminished as may be required.
My improved apparatus has the advantage that it can be arranged to operate
effectually without the use of electrical or other unreliable devices.
It can moreover
be so fitted in a building that neither the air chambers nor the pipes are visible and
the apparatus will without attention remain in working order for a great length
of time.
Although I prefer not to use electrical devices it is obvious that my apparatus might
be arranged in combination with an electric alarm-bell so that the air pressure
communicated through the said pipe to the disc or diaphragm will complete the
electric circuit.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I wish it understood that
I do not claim generally or irrespectively of my improvements herein described a
fire-detector operating by the expansion of air by the heat of the fire, but I
claim :-
:-
First A fire-detector of the kind or class herein before referred to, wherein one or
more pipes are employed for the communication of pressure from the air-chamber to
a device or devices for operating the indicator and releasing a weighted arm whereby
the alarm-apparatus is set in operation.
Second-The improved fire-detector comprising an air-chamber connected by a pipe
with a chamber provided with a flexible disc or diaphragm, and a signal or indicating
device connected with the said disc or diaphragm, substantially as, and for the
purposes, herein before described.
Dated this 20th day of Max 1880
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicant.