IMPROVEMENTS IN APPARATUS FOR INDICATING AND REGISTERING THE PRESENCE OF EXPLOSIVE OR INJURIOUS GASES IN COAL-MINES AND OTHER PLACES
Year: 1883

page_text: LETTERS PATENT to Jacob Catz, of Queen Victoria Street, in the County of
Middlesex, for an Invention of IMPROVEMENTS IN APPARATUS FOR INDICATING
AND REGISTERING THE PRESENCE OF EXPLOSIVE OR INJURIOUS GASES IN
COAL-MINES AND OTHER PLACES Communicated to him from abroad by
François Libin, of Gand, Belgium.
PROVISIONAL SPECIFICATION left by the said Jacob Catz at the Office of
the Commissioners of Patents on the 6th January 1883.
JACOB CATZ, of Queen Victoria Street, in the County of Middlesex,
IMPROVEMENTS IN APPARATUS FOR INDICATING AND REGISTERING THE PRESENCE
OF EXPLOSIVE OR INJURIOUS GASES IN COAL-MINES AND OTHER PLACES," a
communication to me from abroad by François Libin, of Gand, Belgium,
This invention has for its object to indicate the presence of dangerous gases in
coal-mines, rooms of dwelling-houses and other places. For this purpose I place in
the spaces where hydro-carbon and other dangerous gases may accumulate,
indicators constructed as hereinafter described and connected with a registering
apparatus situated near the engine serving to ventilate the mine, or at any other
convenient spot. The indicator consists chiefly of a porous vessel, preferably
cylindrical, closed at one end by an elastic diaphragm, the motion of which is
made to close or break an electric circuit. This may be effected by attaching to
the diaphragm a spring the free end of which is situated opposito a regulating
screw electrically connected with one of two binding posts. Ono binding post is
connected with a battery and the other to an indicating or registering apparatus.
The porous vessel may be enclosed in a casing, suspended by means of a ring and
closed on one or more sides by wire-gauze. When the indicator is suspended near
the top of a gallery or room in which fire-damp, illuminating gas and other
injurious gases lighter than air may accumulate, the porous vessel absorbs instantly
some of the hydro-carbon, gas, thereby causing the diaphragm to swell outward
and to produce a contact with the regulating screw, so as to establish the electric
circuit. The latter may set in action an optic or acoustic signal, or a pencil which
automatically registers on a travelling sheet of paper the state of the diaphragm.
Instead of a porous vessel, a metallic box may be used, the opening of which is
hermetically closed by a porous plate.

page_text: JACOB CATZ, of Queen Victoria Street, in the County of Middlesex,
"IMPROVEMENTS IN APPARATUS FOR INDICATING AND REGISTERING THE PRESENCE
OF EXPLOSIVE OR INJURIOUS GASES IN COAL-MINES AND OTHER PLACES," a
communication to me from abroad by François Libin, of Gand, Belgium.
This invention has for its object to indicate the presence of escaped gas or fire
damp as well as the proportion of these gases to the atmospheric air with which
they are mixed. In the accompanying drawings Fig 1 is a vertical section,
Fig 2 an elevation and Fig 3 a plan of a firo damp indicator embodying the
invention.
The apparatus comprises:
1.) A porous vessel P the orifice of which is covered with an elastic
membrane M.
2.) One or two flexible blades F, according to the destination of the apparatus.
3.) A strong spring R provided with an index fingor or needle Y.
4.) A regulating screw R' for regulating the position of the spring R.
5.) A semi-cylindrical metallic box B.
6.) A scale indicating the quantity of fire-damp or of gas contained in the air.
7.) Two binding screws S, S', one of which communicates with the regulating
spring R and the other with the flexible blade F.
The metallic box B is closed by a wooden cover W to which are secured the
binding posts, the springs, and in the centre a ring A to suspend the whole
instrument. Two small ledges or flanges (not shown in the drawing) may be
provided on the flat face of the metallic box, for adapting the apparatus to be
carried on a stick (from 1 to 2 meters long) to which it inay be secured by means
of a strong copper wire.
Inside of this stick aro two insulated conducting wires connected with binding
scrows situated outside at the top and at the bottom of the stick, as well as with
the apparatus. Thus fixed to the stick, the apparatus is particularly adapted for
the use of engineers and overseers in coal-nines. In this case the equipment is
completed by a waist bolt carrying a small electric bell (from 5 to 6 centimeter
diameter) constructed so that, no spark can be produced at the contact points, and
a small electric pile placed in a strong leather pocket.
Fitted to the side of the belt are two binding screws communicating with the
pile and also with the bell by means of copper wires sewed into the belt.
By means of a flexible string enclosing two conducting wires the stick is
connected with the belt, whereby the electric circuit is completed.
Indicators made for the purpose of indicating quantities of fire damp less than 3 per
cent of the air and gas mixture are provided with a supplementary flexible blade F'
fixed with one end to the edge of the porous vessel P and resting on the elastic
membrane, as shown in Fig 4.
The end, which is bent upward, touches the other blade F near its point of
attachment. The graduation of the indicator has to be made experimentally by
means of special apparatus.
If indicators are fixed in the galleries of mines, they may be connected with a
registering apparatus placed near the ventilating machine, by means of insulated
copper wires enclosed in tubes of lead.
This apparatus, the recording sheet of which may be observed at any moment,

page_text: indicates in a permanent manner the state of the interior of the mine, and shows
instantly where fire damp has accumulated.
The sheet of paper receiving the automatic inscriptions, has to be renewed at
suitable intervals. It serves as a control, and as a means of justification in case of
accident,
The apparatus works as follows:
As soon as fire damp is produced it rises to the vaults of the galleries. Tho
porous vessel then absorbs hydrocarbon gas of which fire damp is chiefly
composed, thereby causes the elastic membrane to swell or bulge outward so as to
establish a contact of the flexible blade with the regulating spring, thereby
closing the electric circuit and setting the electric bell or the registering clock in
action.
I am aware that indicators based on the diffusion of gases and acting by the
expansion of an elastic bag have been made before, and I do not claim this
principle.
Such indicators made with an elastic bag of indiarubber, through which the gas
passes very slowly, are less sensitive than indicators made with a porous vessel
and constructed as described. They also require frequent adjustment and are
consequently not adapted for general use.
Having now described the invention and the most convenient manner of
carrying the same into effect, I wish it to be understood, that I do not limit
myself to the exact details shown by the drawings, but that, what I claim is :-
1. In fire damp indicators or analogous apparatus, the combination of a porous
vessel, with an elastic membrane forming a lid or cover for the said vessel, and
means for indicating or registering the motion of the said membrane, substantially
as described.
2. The combination of porous vessel P, with elastic membrane M, spring F or
equivalent actuated by the motion of the membrane, adjustable regulating spring
and index finger R, regulating screw R' or equivalent for adjusting the position of
such spring, graduated scale C, casing B adapted to hold and protect the working
parts and provided with a facing W for admitting gas to the vessel, and binding
posts S, S or equivalents, one of which is electrically connected with the spring F
and the other with the spring R, substantially as and for the purposes described.
In witness whereof I the said Jacob Catz have hereunto set my hand and seal
this 5th day of July A.D. 1883.