A New or Improved Apparatus for Giving Warning of the Presence of Escaped Gas in Rooms or the like.
Year: 1895

page_text: Date of Application, 15th June, 1895-Accepted, 20th July, 1895
CUMI LEIN
A New or Improved Apparatus for Giving Warning of the Presence
of Escaped Gas in Rooms or the like.
I REGINALD HADDAN of the Firm of Herbert Haddan & Co., of 18 Bucking-
ham Street, Strand, London, W.C., Patent Agent, do hereby declare the nature
of this invention, a communication to me from abroad by José Serra & Co.,
Barcelona in the Kingdom of Spain, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement :-
This apparatus is intended to serve for automatically giving warning when a
dangerous quantity of a gas such as ordinary illuminating gas, has been mingled
with the air of any room, apartment or other space communicating with the
apparatus. It essentially consists of a balance beam one arm of which carries
suspended a hollow, voluminous, unalterable, light and hermetically closed vessel
or body, while the other arm is balanced by a weight of less volume. Said
balance is provided with a metallic pin which on going downward dips in a basin
containing mercury.
Both balance and basin are inserted in the circuit of an
electric bell.
The apparatus is encased in a box communicated by tubes with the places or
rooms of which it is of importance to have changes in the density of the atmosphere
indicated, so that the air in these spaces on becoming less dense will pass through
said tubes and fill the box containing the apparatus.
When it is desired to find out whether the air is mixed with a heavier gas, the
apparatus should be placed on a lower level than that of the space or chamber.
When the balance poiser in the air is surrounded by a mixture of air and lighting
or any other gas of less density, it loses its equilibrium and the voluminous body
will sink thereby immersing its metallic pin in the mercury of the basin and
closing the circuit of the electric bell, which will signal to indicate that a change
in the atmosphere of a space or room that is in communication with the box of the
apparatus, has taken place.
The annexed drawing represents such apparatus in one form of construction, as
the latter may vary.
It consists of a beam B with two arms of unequal length, and resting with
knife edges B³ on a support S1. From one of said arms is suspended a hollow
body C while the other arm is balanced by a weight E attached thereto in a similar
manner. In order to give the body C a larger play of movement, the arm carrying
the same is made considerably longer than the other. It is, however manifest,
that even if these two arms were of equal length, the principal or idea of working
of the said apparatus would in no way be altered.
Body C may be constructed in any suitable shape and form; also of any
material such as glass, brass, aluminium or the like, provided, of course, that the
material is proof against air and gas.
Underneath the hollow body C there is a metallic vessel or basin F fastened by
means of a screw G, to a loop like socket H secured to the bottom of the box, the
spindle of basin F passing through said socket, is thus adapted to regulate or
adjust so as to assume any desired level.
The body C is at its lower extremity provided with a platinum needle to be
immersed in the mercury of the basin or vessel according to the relative position
of arms B. Over the surface of the mercury is a layer of glycerine the object of

page_text: which is to prevent oxydation, of the needle point and keep it covered, lest in the
case where the surrounding atmosphere is composed of an explosive mixture, it
should communicate spark from the electric circuit to that atmosphere which
would cause the latter to explode.
The vessel' or basin F is connected to the positive pole of a battery by means
of the conductors I and I fastened.by, set screw M, while, the support S' for beam B
or the knife edge B³ respectively, has connection with the negative pole by means
of the conductors K and K' fastened by the set screw M. A bell apparatus, is
inserted in the electric, circuit, in..combination, when desired, with registering
apparatus.
As above mentioned, the apparatus is encased by a box. A which latter has loops
or ears adapted for attaching it to the desired and suitable, place. R is the tube
for communication with the space.or room to be controlled as to the,variations of
the density of its atmosphere. O is the air outlet tube of box A. Cocks P and N
serve to air the box A after an observation has been made, so. as, to accelerate the
exit of the mixed atmosphere which it should happen to contain, thereby restoring
the equilibrium of the beam.B.
In the position of equilibrium.the point J is not immersed in, the mercury; con-
sequently, the circuit is interrupted. But should, the atmosphere of the space or
room to be controlled, become lighter, for instance, through an escape of lighting
gas, it will fill the box. A through tube R; the body C will then sink and the
point J.be immersed in the mercury of the vessel or basin F, thereby closing the
circuit and setting the electric bell in operation.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
:-
1.. An automatic apparatus for indicating the presence of gas, comprising a
hollow hermetically closed body suspended from the extremity of a beam which,
in an ordinary or normal atmosphere, is kept in equilibrium by a weight or
counterpoise of much smaller volume suspended from the other extremity of the
beam, the said body being provided with a contact needle underneath of which is
a basin or vessel containing mercury covered with glycerine. or equivalent substance,
so that, when the apparatus looses its equilibrium,, the point will be immersed in
the mercury thereby closing an electric circuit that will set...an electric bell
apparatus in operation, the whole apparatus being.encased in a box communicating
through a tube with the room or space the changes in the atmospheres of which it
is.desired to ascertain, substantially.as.described.
2. The construction of this apparatus as described and illustrated in the drawing
for the purpose described.
Dated this 15th day of June 1805
R: HADDAN.