A New or Improved Fire-damp Detector.
Year: 1895

page_text: Date of Application, 29th Aug., 1895
Complete Specification Left, 24th Oct., 1895-Accepted, 30th Nov., 1895
A New or Improved Fire-damp Detector.
We GUSTAV ADOLF LYNCKER, Lieutenant Retired List, and ANTON
SCHROPP of no occupation, both of 94 Gleiszheimerstrasse Munich in the
Empire of Germany, do hereby declare the nature of this invention to be as
follows:-
The purpose of this invention is to provide a new or improved fire-damp detector
for use in mines, which may be carried by the miner to the place in which he is
working and there suspended in order to give immediate notice to him of the
presence of fire damp even before the latter becomes so diffused as to form an
explosive mixture with the air.
The device comprises a casing having means for closing it air tight and
containing a dry electric battery or the like and an electric signal bell. The lower
part of the casing forms a recessed chamber which is closed below from the outer
air by a porous diaphragm for instance a plate of baked unglazed clay. This
chamber narrows above and forms a tubular neck in which accurately fits a stopper
closing the neck air-tightly yet capable of moving up and down in the neck without
friction sufficient to prevent it moving under variation in air pressure within the
chamber and within the casing respectively. This stopper may be made of leather
or prepared wood, and on rising it is adapted to close a circuit between the bell
and the battery by which the former is set in action. The casing has means for
suspending it from the roof of the working or in other suitable places and may
have below a flat collecting bell or hood for leading gases directly to the aforesaid
diaphragm.
Fire damp and the like on reaching this apparatus diffuse themselves through the
porous diaphragm and before the air can diffuse itself from within the chamber
through the said diaphragm there will be an increase of pressure sufficient (the
parts being duly proportioned) to lift the stopper and close the circuit by which
the signal bell is set in action.
Dated this 29th day of August 1895.
HERBERT HADDAN & Co.,
Agents to Applicants.
A New or improved Fire-damp Detector.
We, GUSTAV ADOLF LYNCKER Lieutenant Retired List and ANTON
SCHROPP, of no occupation, both of 94 Gleiszheimerstrasse Munich in the Empire
of Germany 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 purpose of this invention is to provide a new or improved fire-damp detector
for use in mines which may be carried by the miner to the place in which he is
working and there suspended in order to give immediate notice to him of the
Price 8d

page_text: presence of fire damp even before the latter becomes so diffused as to form an
explosive mixture with the air and which can also be so connected as to give
warning also elsewhere not necessarily in a central station, but at any prearranged
place in the workings.
The invention is based mainly on the expansive property of air or gas like
substances, which though regulated by certain recognised and known laws can only
be used for practical purposes, when an apparatus is used controlling the expansion
according to previous calculations and measurements which is claimed to be
accomplished by this invention.
On the bottom of a cylinder shaped casing, Fig. 1, a metallic funnel shaped
chamber c, Figs. 1 and 7, is inserted which is closed below at 1 cm. height air
tightly by means of a porous plate d of baked unglazed clay. The cylindrical
sides rise 2 cm. above the plate d, the upper half of the chamber narrows for the
distance of another 2 cm. until it measures 19 mm. across (see Fig. 7) and runs out
in a neck b, 38 mm. high and 19 mm. wide (Figs 1, 3, and 7).
In the upper part of this neck is fitted a light stopper a 15 mm. high and of
conical form above, made of pressed leather or of prepared wood; this stopper
closes air tightly but is capable of moving up and down in the neck without
friction or pressure and will thus recede i.c. rise when the air is expanded
(Figs. 1, 3, 7). On the upper part of this stopper a thin platinum ring is
fitted 3 mm. high (Figs. 1, 3, 4). The stopper itself is inserted into the tube
(neck b) in such a manner that the platinum ring will be 0.5 mm. from the
upper end.
This neck b may be separated at n. The end of the neck is insulated by a thin
rubber disc p Figs. 5 aud 4.
At both sides of the neck the bearers o o¹ are fitted which are provided with
electrical binding screws s s¹ which receive the platinum points which latter
represent the ends of the wires m m¹ and are approached to about 2-3 mm. and
are fixed immediately above the insulating ring p.
C
At the side of the chamber c in the casing are placed the dry battery and the
bell g in such a manner that the wire will form a contact between battery and
bell and the other poles are connected by the wires m² m³ with the electric contact
posts s s¹.
Over the end of the neck and consequently over the whole contact point is
screwed a protecting cap a.
The cylindrical casing which has a width of about 45 cm. and a height of
about 20 cm. is hermetically closed with a cover q by means of a rubber ring and
screws and is provided in the centre with a handle i for suspending or carrying
the apparatus.
Fig. 6 represents on a smaller scale an exterior view of the closed casing with a
flat collecting bell or hood e. In the hollow part below the plate d this flat
collecting bell or hood e may be screwed in for leading gases directly to the
aforesaid plate. This bell is made very flat and wide.
The apparatus need only be suspended from the roof of the working. The gases
produced and mounting upwards will collect in the collecting bell and be thus
brought to the plate d.
By the quicker diffusion of fire damp the latter will penetrate through the
plated over a surface of about 20-22 cm. diameter and here in the suddenly
narrowing space above the plate it will come in contact with atinospheric air,
whereby a compression of this air and a pressure on the lower part of the stopper a
will be occasioned.
The construction Fig. 7 of the apparatus will ensure the necessary expansion for
the slight lifting of the stopper a before the expansion in the chamber is again
neutralised by the return diffusion of the air.
By the moving of the stopper a the electric contact is formed by platinum ring t
and platinum points and which are fitted directly above t and the alarm bell is
actuated. The apparatus will also act on a sudden and considerable escape of fire

page_text: damp before the necessary mixture with atmospheric air has taken place which
mixture is necessary before explosion takes place.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
1. An apparatus for detecting fire damp having in an air tightly closed casing h
a chamber c closed below by a thin porous plate of clay and running out in a
cylinder having a stopper a with platinum ring which is lifted by the gases
penetrating through the porous plate thus causing the platinum ring t and
points 1, 1, or equivalent means to form an electric contact by which an electric bell
is actuated.
2. The combination with the above apparatus of the collecting bell e arranged
.
HERBERT HADDAN & Co.,
18, Buckingham Street, Strand, London, W.C., Agents to the Applicants.