IMPROVEMENTS IN APPARATUS FOR SUPPORTING RESPIRATION AND LIGHT IN- SUFFOCATING OR EXPLOSIVE ATMOSPHERES.
Year: 1872

page_text: LETTERS PATENT to John Imray, of No. 20, Southampton Buildings,
Chancery Lane, in the County of Middlesex, for the Invention of
*IMPROVEMENTS IN APPARATUS FOR SUPPORTING RESPIRATION AND LIGHT IN-
SUFFOCATING OR EXPLOSIVE ATMOSPHERES.". -A communication from
abroad by Louis Denayrouze, of No. 23, Boulevard de Strasbourg,
Paris, France..
-
Sealed the 11th January 1873, and dated the 17th July 1872.
PROVISIONAL SPECIFICATION left by the said John Imray at the
Office of the Commissioners of Patents, with his Petition, on the
17th July 1872..
I, JOHN IMRAY, of No. 20, Southampton Buildings, Chancery Lane,
in the County of Middlesex, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN APPARATUS FOR SUPPORTING RESPIRATION AND:
LIGHT IN SUFFOCATING OR EXPLOSIVE ATMOSPHERES," to be as follows :—
This Invention relates to apparatus for furnishing and regulating
the supply of air for respiration and light to miners and other employed
T

page_text: in localities where the atmosphere is of a suffocating or explosive
character, and to lamps used in connection therewith.
The portable air supplying apparatus consists of a strong vessel or
reservoir charged with compressed air, and provided with means of
regulating the pressure of the air withdrawn from it for respiration and
for supporting the combustion of the lamp.
The reservoir with its regulating apparatus is mounted on a framing
so that it can be borne on the back of the miner, and is fitted with two
sets of regulating apparatus, from the one of which a flexible pipe is
led to the mouth of the miner to supply him with air at ordinary
pressure for respiration, and from the other a flexible. pipe is led to the
lamp to supply it with air for combustion.
The regulating apparatus for the respiration of the miner consists
of a chamber attached to the air reservoir and communicating with it
by a pipe fitted with a valve opening inwards towards the reservoir.
The chamber is covered by a flexible diaphragm, which may be of
caoutchouc or leather, or of, thin corrugated sheet metal, or may be partly
of sheet metal with caoutchouc or leather or other flexible material, so
arranged that it can yield a little outwards or inwards, according as the
pressure of air within the chamber exceeds or falls short of the pressure
of the external atmosphere. This diaphragm in its central position is
in contact with the stem of the valve opening into the reservoir. The
pipe for respiration leads from the chamber to the miner's mouth.
When he by drawing a breath reduces the pressure within the chamber
the diaphragm being forced inwards by the pressure of the external
atmosphere bears on the valve stem, and thereby pushes the valve open
so as to admit a supply of air from the reservoir to the chamber.
1
When owing to this supply. the pressure in the chamber is made to
exceed that of the external atmosphere the diaphragm bulging outwards
permits the valve to close so as to stop farther supply from the reservoir
until the pressure in the chamber is again sufficiently reduced to demand
a fresh supply. Thus by employing a diaphragm of large area acting
on a valve of small area the pressure in the chamber undergoes varia-
tions of very small amount, being always maintained very nearly at the
same pressure as that of the atmosphere, notwithstanding that there may
be a very great excess of pressure in the reservoir itself.

page_text: For regulating the pressure of air supplied to the lamp an apparatus
of similar construction is enclosed in an external chamber, to which air
can be admitted from the reservoir by a cock or valve worked by hand,
so that in this external chamber a pressure can be maintained exceeding
that of the external atmosphere, and this pressure can be varied at:
pleasure by admitting air from the reservoir to the external chamber,
or allowing air to issue from the external chamber, so as to put more or
less pressure on the regulating diaphragm.
Instead of making reservoirs as above described portable they may
in many cases be placed in fixed positions, and the miners may be
supplied directly by flexible pipes from their regulating chambers, or
the portable reservoirs carried by the miners may be supplied from
them. It is also convenient to have such reservoirs mounted on trucks,
so that they may be readily conveyed to different parts of a mine or
working for the supply of the portable reservoirs.
'
In supplying the reservoirs by pumps it is essential to prevent access
of dust or grit which might interfere with the action of the valves of the
pumps and regulators. For this purpose the supply pipe of the pumps
is at some convenient part of its length provided with means of sifting
the air drawn in. A convenient method of effecting this is to fit two
lengths of the supply pipe with hemispherical mouth pieces provided"
with flanges by which they can be bolted together, a sheet of felt or
other porous fabric being held between them. By this means the air
flowing along the pipe is sifted of dust or grit in its passage through the
porous fabric.
The lamp used in connection with the reservoirs and regulating
apparatus above described has a double casing of metal which may be
of spherical or spberoidal form, with an aperture at the side fitted with
a glass. The air supplied to the lamp enters the space between the.
two casings, and thus tends to keep the outer casing cool, and also
receives heat from the casings before it reaches the flame, which it does
by passing through apertures in the lower part of the inner casing near
the flame. In the upper part of the casing, immediately above the flame,
is an aperture fitted with a light conical valve opening upwards, and
above this valve are fixed two or more diaphragms of wire gauze. The
pressure of the air supplied to the lamp being somewhat above that of
the external atmosphere, the products of combustion having ‘a like
pressure raise the light valve and escape through the meshes of the

page_text: wire gauze. Should at any time the pressure within the lamp fall
below that of the external àtmosphere the valve closes, so as to prevent
access of external air or gas to the flame, and the wire gauze diaphragms
prevent communication of flame to any explosive mixture of gas
without.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Imray in the Great Seal Patent Office on.
the 16th January 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
IMRAY, of No. 20, Southampton Buildings, Chancery Lane, in the
County of Middlesex, send grecting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Seventeenth day of July, in the year of
our Lord One thousand eight hundred and seventy-two, in the thirty-
sixth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said John Imray, Her special licence, that
I, the said John Imray, my executors, administrators, and assigns, or
such others as I, the said John Imray, my executors, administrators,
and assigns, should at any time agree with, and no others, from time
to time, and at all times thereafter during the term therein expressed,
should and lawfully might make, use, exercise, and vend, within the
United Kingdom of Great Britain and Ireland, the Channel Islands,
and Isle of Man, an Invention for "IMPROVEMENTS IN APPARATUS FOR
SUPPORTING RESPIRATION AND LIGHT IN SUFFOCATING OR EXPLOSIVE ATMOSPHERES,"
a communication to me from abroad by Louis Denayrouze, of No. 23,
Boulevard de Strasbourg, Paris, France, upon the condition (amongst
others) that I, the said John Imray, my executors or administrators, by
an instrument in writing under my, or their, or one of their hands and
seals, should particularly describe and ascertain the nature of the said
Invention, and in what manner the same was to be performed, and cause
the same to be filed in the Great Scal Patent Office within six calendar
months next and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said John Imray, do hereby declare
the nature of the said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the

page_text: following statement thereof, reference being had to the accompanying
Sheet of Drawings, and to the figures and letters marked thereon, that
is to say:
This Invention relates to apparatus for furnishing and regulating the
supply of air for respiration and light to miners and others employed in
localities where the atmosphere is of a suffocating or explosive character,
and to lamps used in connection therewith.
The portable air supplying apparatus consists of a strong vessel or
reservoir charged with compressed air, and provided with means of
regulating the pressure of the air withdrawn from it for respiration and
for supporting the combustion of the lamp.
The reservoir with its regulating, apparatus is mounted on a framing
so that it can be borne on the back of the miner, and is fitted with two
sets of regulating apparatus, from the one of which a flexible pipe is
led to the mouth of the miner to supply him with air of ordinary
pressure for respiration, and from the other a flexible pipe is led to the
lamp to supply it with air for combustion.
The regulating apparatus for the respiration of the miner consists of
a chamber attached to the air reservoir, and communicating with it
by a pipe fitted with a valve opening inwards towards the reservoir.
The chamber is covered by a flexible diaphragm, which may be of
caoutchouc or leather, or of thin corrugated sheet metal, or may be
partly of sheet metal with caoutchouc or leather or other flexible
material, so arranged that it can yield a little outwards or inwards,
according as the pressure of air within the chamber exceeds or falls
short of the pressure of the external atmosphere. This diaphragm in.
its central position is in contact with the stem of the valve opening into
the reservoir. The pipe for respiration leads from the chamber to the
miner's mouth. When he by drawing a breath reduces the pressure
within the chamber, the diaphragm being pressed inwards by the
pressure of the external atmosphere bears on the valve stem, and thereby
pushes the valve open so as to admit a supply of air from the reservoir
to the chamber.
When owing to this supply the pressure in the chamber is made to
exceed that of the external atmosphere the diaphragm bulging outwards
permits the valve to close so as to stop farther supply from the reservoir
until the pressure in the chamber is again sufficiently reduced to demand

page_text: a fresh supply. Thus by employing a diaphragm of large area acting
on a valve of small area the pressure in the chamber undergoes
variations of very small amount, being always maintained very nearly
at the same pressure as that of the atmosphere, notwithstanding that
their may be a very great excess of pressure in the reservoir itself.
For regulating the pressure of air supplied to the lamp an apparatus
of similar construction is enclosed in an external chamber, to which air
can be admitted from the reservoir by a cock or valve worked by hand,
so that in this external chamber a pressure can be maintained exceeding
that of the external atmosphere, and this pressure can be varied at
pleasure by admitting air from the reservoir to the external chamber, or
allowing air to issue from the external chamber, so as to put more or less
pressure on the regulating diaphragm.
Instead of making reservoirs as above described portable they may in
many cases be placed in fixed positions, and the miners may be supplied
directly by flexible pipes from their regulating chambers, or the portable
reservoirs carried by the miners may be supplied from them. It is
also convenient to have such reservoirs mounted on trucks, so that they.
may be readily conveyed to different parts of a mine or working for the
supply of the portable reservoirs.
In supplying the reservoirs by pumps it is essential to prevent access
of dust or grit which might interfere with the action of the valves of
the pumps and regulators. For this purpose the supply pipe of the
pumps is at some convenient part of its length provided with means of
sifting the air drawn in. A convenient method of effecting this is to
fit two lengths of the supply pipe with hemispherical mouth pieces
provided with flanges by which they can be bolted together, a sheet of
felt or other porous fabric being held between them. By this means the
air flowing along the pipe is sifted of dust or grit in its passage through
the porous fabric.
The lamp used in connection with the reservoirs and regulating appa-
ratus above described has a double casing of metal, which may be of
spherical or spheroidal form with an aperture at the side fitted with a
glass. The air supplied to the lamp enters the space between the two
casings, and thus tends to keep the outer casing cool, and also receives
heat from the casings before it reaches the flame, which it does by
passing through apertures on the lower part of the inner casing near the

page_text: flame. In the upper part of the casing, immediately above the flame, is
an aperture fitted with a light conical valve opening upwards, and
above this valve are fixed two or more diaphragms of wire gauze. The
pressure of the air supplied to the lamp being somewhat above that of
the external atmosphere, the products of combustion having a likė
pressure raise the light valve and escape through the meshes of the
wire gauze. Should at any time the pressure within the lamp fall below
that of the external atmosphere the valve closes, so as to prevent access
of external air or gas to the flame, and the wire gauze diaphragms
prevent communication of flame to any explosive mixture of gas
without
Fig. 1 represents a vertical section, and Fig. 2 a front view of a double
regulating reservoir constructed according to this Invention for supplying
air for the respiration of a miner and for the combustion of a lamp,
A is the reservoir of compressed air made in two chambers communi-
cating with each other by a pipe; B is the regulating chamber for
respiration, which has a lid provided with a bent rim of caoutchouc,
leather, or other flexible and air-tight material by which it is connected
to the sides of the chamber so that it can move a little outwards or
inwards, according as the pressure in the chamber B exceeds or falls
short of that of the external air. The reservoir A is connected with the
chamber B by a small passage fitted with a conical valve K, the stem of
which is connected to the moveable lid of the chamber. A pipe A¹ fitted
with a stop-cock admits air from a compressing pump to charge the
reservoir A, and a pipe B¹ to which a caoutchouc or other flexible tube
is connected conveys air from the regulator B to the mouth of the miner.
When he takes a breath the pressure in the regulator B is reduced, and
the atmospheric pressure acting on its lid pushes it inwards, and thereby
opens the valve K by which a fresh supply is admitted from the
reservoir A to the regulator B, raising the pressure in the latter and
forcing its lid outwards so that the valve K is again closed.
The lower part of the reservoir A is provided with apparatus for giving
a regulated supply of air to the lamp. In this case a regulating
chamber D is fitted like the chamber B with a moveable lid C connected
to the stem of a valve L, and the regulator is covered by a cașing H.
A passage provided with a stop-cock R forms a communication from the

page_text: reservoir A to a orifice O, opening into the interior of the casing H.
By opening the cock R a certain quantity of compressed air is admitted
to the casing H until the pressure therein is such as is necessary for the
supply of the lamp, somewhat exceeding the pressure of the atmosphere.
The interior of the regulator D communicates by a passage D' with the
lamp.
Whenever by the abstraction of air for combustion the pressure within
the regulator D falls below that of the air within the casing H the lid C
is pressed inwards, the valve L is opened, and a fresh supply of air
flows from the reservoir A into the regulator D, raising the pressure
therein and forcing its lid outwards, so that the valve L is again closed.
When the pressure within the casing H is too great it can be relieved
by unscrewing the plug Y. This pressure may be thus regulated at will
'so as to give a greater or less velocity of current to the lamp.
The two parts of the reservoir A and the two regulating apparatus
above described are mounted on a plate or frame X which is strapped
on the back of the miner. By means of the regulating apparatus above
described the quantity of air consumed both for respiration and for the
combustion of the lamp is reduced to a minimum and is rendered
uniform notwithstanding the change of pressure in the supply reservoir.
Fig. 3 represents a vertical section of the lamp to be used in connection
with the air regulating apparatus described above; R is the reservoir of
oil, petroleum, or other combustible, and B a suitable wick or burner
surrounded by a cylindrical glass V. The cover of the glass has a small
aperture fitted with a conical valve S forming the bottom of an outlet
passage which is covered with wire gauze P and surrounded by a wire
gauze screen P¹. An air passage fitted with a regulating stop screw Y
is connected by a flexible pipe with the passage D', in Fig. 1, and com-
municates with an air channel I surrounding the flame and provided
with numerous apertures for the issue of air into the space, enclosed by
the glass.
'
The pressure in the regulator D (Fig. 1) being maintained a little
above atmospheric pressure air will flow thence by the passage D' and
the channel I to support the combustion of the lamp and raise the
_valve S by which the products of combustion will escape. Should the
pressure within the lamp glass fall below that of the atmosphere the
valve S will close and prevent access of explosive gas from without.

page_text: w mile the valve remains open the wire gauze cover and screen of the
outlet prevent the communication of flame from within the lamp to'
combustible gases outside. By leading the air supply round the wick in
the passage I excessive heating of the parts near the wick is prevented
and the air is warmed.
Fig. 4 represents a longitudinal section of one of the main air
reservoirs M for the supply of portable reservoirs such as has been
described above in reference to Figs. 1 and 2. The reservoir M is made
of such strength as to sustain a very high internal pressure, which may
practically amount to 30 atmospheres. The portable reservoirs A (Figs.
1 and 2) being of lighter construction should be charged with air at a
more moderate pressure, as for example a pressure of two atmospheres.
In order to supply the portable reservoirs at such moderate pressure
the reservoir M is provided with a regulator D constructed and acting
in a manner similar to that already described for the supply of air to the
lamp; R is the stop-cock by which air is allowed to pass from the body
of the reservoir M to the interior of the casing H until the pressure
thercin is raised to that which is desired, say, 2 atmospheres. Should
the pressure be in excess a certain quantity of air can be allowed to
escape by a stop-cock H²; D is the regulating chamber with moveable
lid connected to the stem of a valve L, and O is a passage to a branch
pipe to which any of the portable reservoirs can be connected for the
purpose of charging. It will be seen that the pressure within the
casing H being constant the reservoirs, owing to the action of the
regulating apparatus, can only be supplied with air at or near that
pressure, however much greater may be the pressure in the reservoir M.
A number of separate reservoirs, such as N, can be connected by
branches P2 and connecting pipes with the reservoir M. Such reservoirs
may be conveniently arranged as shewn in the end view, Fig. 6, where
five supply reservoirs N are connected with one regulating reservoir M.
These connected reservoirs may be stationary or they may be mounted
on trucks to be moved from place to place.
"
Fig. 5 represents a section of an arrangement of sifting the air
supplied to the compressing pumps so as to prevent access of dust, grit,
or other mechanical impurities. This arrangement consists of two
hemispherical mouth pieces S¹, S³, to the air pipes, bolted together with
a disc of felt or other porous fabric F held between their flanges.

page_text: Having thus described the nature of this Invention, and in what
manner the same is to be performed, as communicated to me by my
foreign correspondent, I claim,-
First. The use of portable air reservoirs constructed and acting sub-
stantially as described with reference to Figs. 1 and 2 for the regulated
supply of air for respiration and for combustion of a lamp in suffocating
or explosive atmospheres.
Second. The use in connection with air reservoirs such as are above
referred to, of safety lamps, constructed and acting substantially, as
described with reference to Fig. 3.
Third. The use of main reservoirs for supplying air at regulated
pressure, constructed and arranged substantially as described with
reference to Figures 4 and 6.
Fourth. The use of apparatus for sifting the air, substantially as
described with reference to Fig. 5.
In witness whereof, I, the said John Imray, have hereunto set
my hand and seal, this Fifteenth day of January, in the year
of our Lord One thousand eight hundred and seventy-three.
JOHN IMRAY. (L.S.)