An Automatic Electric Fire Alarum and indicator of Heavy Air in a Room or other Enclosed Space.
Year: 1895

page_text: Date of Application, 1st July, 1895
Complete Specification Left, 1st Apr., 1896-Accepted, 1st July, 1896
PROVISIONAL SPECIFICATION.
An Automatic Electric Fire Alarum and indicator of Heavy Air in
a Room or other Enclosed Space.
We, AUGUST HANSEN of 52 Nörre voldgade Copenhagen, Denmark, Engineer
and HANS HANSEN FRIMAND, of 142 Borgergade, Copenhagen, aforesaid,
Gentleman, do hereby declare the nature of this invention to be as follows:-
The object of this invention is to give an alarum in case of fire breaking out in
an enclosed space and in case the air becomes heavy and unhealthy.
Within a box is suspended in a fork with knife edges a delicately balanced lever
having at one end a disc or dish and at the other end a small adjustable weight.
When this end rises it enters between two fine contact springs which by wires are
connected to a battery and to an electric bell. Over the box is a hopper and above
that a screen.
When this apparatus is placed say 10 or 12 inches from the ceiling
against the outer wall containing windows and with the screen in a slanting position
to the sill, then the mere burning of a newspaper in some part of the room will
produce an air current (partly consisting of carbon dioxide) which tends towards
the ceiling and having reached the latter turns down again whereby some of it will
enter the hopper which serves to collect it and pass down against the disc, causing
the latter to be lowered and the opposite end of its lever to be raised and to
enter between the two springs thus completing the electric circuit through the
wires so that the alarum is sounded. The balance lever is set in unstable
equilibrium and will tip up by an overweight of 2 centigram on the disc.
In the same manner the apparatus operates for airing and ventilating, when
placed in a sick room, hospital, barrack room or other place and adjusted according
to the rotating air current which is found in the room. As soon as the air becomes
surcharged with carbon dioxide by the local exhalations the alarmn will at once be
sounded in the manner described and thus advise the attendants who can then see
to the airing or ventilating of the room.
The disc end of the balance lever may by a silken cord be connected to a small
air turbine against which the air current strikes in its descent after it has passed
the disc, gliding down along the wall of the box and causes a partial rotation of the
turbine thus assisting the pressing of the other end of the balance lever up between
the spring contacts with greater force.
Dated this 1et dar of Jul. 1905
JENSEN & SON,
77 Chancery Lane, London, W.C., Patent Agents.
COMPLETE SPECIFICATION.
An Automatic Electric Fire Alarum and Indicator of Heavy Air in
a Room or other Enclosed Space.
We. AUGUST HANSEN of 52 Nörre voldgade Copenhagen, Denmark, Engineer,
and HANS HANSEN FRIMAND, of 142 Borgergade, Copenhagen, aforesaid,
Gentleman, 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 :-
The object of this invention is to give an alarum in case of fire breaking out in
au enclosed space and in case the air becomes heavy and unhealthy.

page_text: Fig. 1 is vertical longitudinal section, Fig. 2 vertical transverse section and
Fig. 3 plan of an automatic apparatus constructed according to this invention.
Within a box a is suspended in a fork b with knife edges e a delicately balanced
lever d having at one end a disc or dish e, and at the other end a small adjustable
weight f. When this latter end rises it enters between two fine contact springs 9 g
which by wires h h are connected to a battery and to an electric bell. Over the
box a is a hopper i and above that a screen k. When this apparatus is placed so
that the top of the box a cemes say usually 10 or 12 inches from the ceiling against
the outer wall containing windows, and with the screen k in a slanting position to
the wall, then the mere burning of a newspaper in some part of the room will
produce an air current (partly consisting of carbon dioxide), which tends towards
the ceiling, and having reached the latter turns down again whereby some of it
will enter the hopper i which serves to collect it and pass down against the disc e,
causing the latter to be lowered and the opposite end of its lever d to be raised
and to enter between the two spring contacts thus completing the electric
circuit through the wires hh so that the alarum is sounded. The balance
leverd is set in unstable equilibrium and will tip up by an overweight of
2 centigram on the disc.
In the same manner the apparatus operates for airing and ventilating a sick
room, hospital, barrack room or other place when it is fixed just in the spot where
the air current in the room after having risen against the ceiling is deflected there-
from against the wall. As scon as the air becomes surcharged with carbon dioxide
by the local exhalations, the alarum will at once be sounded in the manner
described and thus advise the attendants who can then sec to the airing or
ventilating of the room.
As shewn in the vertical sectional view Fig. 4 and plan Fig. 5 the disc end of
the balance lever d may by a silken cord m be connected to a snall air turbine
against which the air current strikes in its descent after it has passed the disc e,
gliding down along the wall of the box a and causes a partial rotation of the
turbine thus assisting the pressing of the other end of the balance lever d up
between the spring contacts g with greater force.
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. Automatic alarum applied to an outer wall in a room at or near a window and
intended to indicate a fire in a room or the presence of an undue amount of carbon
dioxide in the air of same, consisting of a disc or dish in connection with a hopper
and screen, said disc being on one end of a balance lever, and caused to be
depressed by a current of air deflected from the ceiling, said air current being
produced by the smoke rising against the ceiling from a fire breaking out in
the room or by the production of a surcharge of carbon dioxide in the room,
whereby the other end of the lever is raised and enters between spring contacts
in an electric bell and battery circuit and sounds the alarum, substantially as
set forth.
2. The construction of automatic alarum apparatus described with reference to
Figs. 1, 2 and 3.
3. The construction of automatic alarum apparatus described with reference to
Figs. 4 and 5.
Dand th
T
1
C A
1 1000
JENSEN & SON,
77 Chancery Lane, London, W.C., Patent Agents.