IMPROVEMENTS IN THE CONSTRUCTION OF MINERS SAFETY LAMPS
Year: 1885

page_text: I, WILLIAM CLIFFORD Abbey View, Norton Woodseats, near Sheffield in the
County of Derby Mining Engineer do hereby declare the nature of my said
invention for "IMPROVEMENTS IN THE CONSTRUCTION OF MINERS SAFETY LAMPS
to be as follows:
My improvements in the construction of safety Lamps for miners, refers more
particularly to the following objects, and parts, of such lamps.
1st Admitting air to feed the flame of wick.
2nd Ventilating the lamp, and carrying off the products of combustion.
3rd to the gauzes.
4th to the form of the burner.
The first part of my improvements is effected by admitting the air into an
annular chamber (either continuous or divided), through openings or ports cut
through its outer wall, at nearly a tangent to its circumference. This annular
entrance chamber may be placed either below or above the glass, as desired. From
the annular chamber the air passes through other ports in the inner wall, and
through one or more gauzes or perforated plates into the lamp.
The second part of my improvement is to produce a draught to condense the hot
gases and to provide a reservoir of or means of detaining carbonic acid gas or
other products of combustion, which is effected by the use of a metal chimney
attached to a base plate or diaphragm just above the top of the glass, with a
ventilating regulator or cap at the top of the chimney, to prevent the outer. air
entering the chimney, and by surrounding the chimney with a skin of fixed air
contained between an outer and inner casing.
The chimney is constructed so as to form a long continuous flue from the base
plate before mentioned, to a cap plate or upper diaphragm, for the purpose of
cooling the products of combustion by prolonged contact with the metal, and also
to retain the products of combustion in its angles or bends.
In the third part of my invention I make the inlet gauzes of perforated metal of
good conducting power, (such as aluminium) to carry off the heat of burning fire
damp, and to keep that portion which is in contact with the said fire damp, below
the point of ignition. Or the gauzes may be coated or faced with a metal that will
melt before such point of ignition is reached, so that it will run over and close up
the apertures and thus cut off the air supply.
The fourth part of my invention is the use of an argand burner in Miners Lamps
arranged to take its air supply through the centre of the annular wick, by means
of an L shaped air pipe fastened to the bottom of the oil vessel.
Dated the 20th day of Jonverse 1005
ROBT F. DRURY,
Agent for the Applicant.

page_text: I WILLIAM CLIFFORD Abbey View, Norton Woodseats, near Sheffield, in the
County of Derby Mining Engineer do hereby declare the nature of my invention
for IMPROVEMENTS IN THE CONSTRUCTION OF MINERS SAFETY LAMPS and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement that is to say:―
The improvements contained in my invention refer to
1-The admission of air to the wick flame.
2-The ventilation of the Lamp, and carrying away the products of combustion.
3-The gauzes or perforated plates.
4-The application and form of burner. And the objects of the invention are
First, Immunity from firing externally when placed in an inflammable mixture
of air and firedamp moving at great velocity.
Second To obtain a good steady light which will not readily go out when the
Lamp is either tipped on one side, shaken, or otherwise disturbed, and that will
burn in stagnant air or in a high wind.
To effect the first improvement, the air is admitted into an annular chamber
(either continuous or divided) through openings or ports cut through the outer wall
of the Lamp body, at a tangent or other angle to the radius. The annular chamber
may be placed either above or below the cylindrical glass as desired. From the
annular chamber the air passes through other ports in the inner wall, and through
one or more gauzes or perforated metal plates into the lamp. These parts are of
such dimensions as only to supply the required quantity of air to the wick flame.
To effect the second improvement, I use a continuous flue of metal of any
suitable form uniting a base plat or diaphragm at the top or thereabouts of the
glass cylinder sorrounding the wick flame, with another diaphragm near the top of
the Lamp, and surmounted by a cap, coil or ventilator.
This cap like the air inlet is protected by angular ports and an annular chamber
from the direct impact of the wind.
I surround the said flue with a skin of fixed air by placing an outer case round
it, and at a little distance from it.
I also use a glass chimney to connect the burner with the bottom of the said
flue, to create draught, and to ensure the combustion of all the air or gaseous
mixture entering the lamp through the inlet.
Thus there is continuously interposed a zone of incombustible gases between the
flame and the outlet in the chimney and flue and in the recesses and angles of
same.
In the third improvement, I use plates of good conducting metal, such as
aluminium or copper, perforated, in place of the usual wire gauze, these plates
are shaped so that they will readily transmit heat from that part of their surface
in contact with burning fire-damp to other larger parts of their surface in contact
with cool portions of the lamp or with the fresh air. I also use other perforated
plates for passing air into and out of the lamp. I make these last mentioned
plates with a face layer of a metal that will fuse at a lower temperature than the
igniting point of fire-damp, and the back layer of a metal that will not so fuse.
In contact with burning fire damp the more fusible metal melts and runs over
and closes the perforations in the other portion of the plate, thus cutting off the
supply of air.

page_text: The fourth improvement consists in the adaptation and use of the circular.or
argand burner to a miners safety lamp and the method of supplying air to the
centre of such burner through a bent tube fastened to the bottom of oil vessel.
And in order that my said invention may be clearly understood I have annexed
hereto a sheet of drawings illustrating a lamp in which my improvements are
carried out, and in which the same letters of reference indicate the same or
similar parts in any of the figures.
Fig. 1 is a sectional elevation, through the middle of a lamp with the air feed
above the glass.
Figs 2, 3, 4, 6, 7, are horizontal sections on lines marked in the other figures.
Fig 5 is a sectional elevation of a lamp having the air feed below the glass.
The air to support combustion enters by the ports a, a, and that to carry away
the products of combustion and ventilate the lamp, by the ports a¹ a¹ into the
annular spaces b, b. The ports are arranged in two rows, one above another, and
as will by seen in Figs 2 and 3, the bottom row enter the annular chamber in a
direction nearly opposite to those in the top row, so that the air currents meeting
in opposition, their force is diminished and they are brought to a state of rest.
The wick flame is thus protected from the direct impact of a high velocity which
may be possessed by the outer air.
If more air enters than is required for ventilation or combustion it passes out at
the other side.
The air to feed the wick flame passes from the annular chamber b, through inner
ports c, c, through peforations in the conducting metal plates d, d, (when the feed
air enters above the glass as in Fig. 1) then down between the glass f, and the
chimney e, to other perforated plates g, g, with fusible metal face, but in a lamp in
which the feed air enters below the glass as in Fig 5, the parts c and g are only
separated by a short annular space with metal walls.
The air in both cases on reaching the lower part of lamp, divides, part passing
through the L shaped tube i, to centre of burner, and part outside the wick tube to
flame.
Usually the products of combustion ascend the glass chimney e, e, and flue k, k,
to the outlet, passing through perforations in compound metal plate l, with fusible
face and conducting metal plate into the cap p: Here they mingle with the air
entering at one, side, and are carried out of the cap and through the ports in the
outer skin in the other side of the lamp, see Figs 6 & 7.
The fusible face of the plates g g, and 1, 1, may be of any alloy that will not melt,
from the heat ordinarily given off by the wick flame, but that will melt and run
over the holes in the lower part of plate so as to cut off the inlet and outlet, before
a temperature is reached that would ignite fire-damp or that would damage the
structure of the lamp.
It will be seen from the drawings, that the whole of the air entering the gauzes
or perforated plates d, d, and g g, must pass through or in contact with the wick
flame to reach the outlet, and that in case of such air being mixed with fire-damp
in proportions that would render it inflammable, the whole of such inflammable
mixture is ignited and passes up the glass chimney e, and flue k, k, as products of
combustion.
This action confines any ignition of fire-damp to the lower part of the lamp,
between which and the outlet are the said products of combustion-in chimney e,
the flue k, k, and spaces or recesses-without any admixture of unburnt air.
The upper ports a, a, and b, b, being similar in construction, the lower or inlet
ones govern the supply of wind to ventilate the lamp admitting to the cap, only
sufficient to sweep away the products of combustion.
Figs 6 & 7 are horizontal sections showing these ports and chamber.
In Figs 1 & 5, d, and m, show the method of constructing conducting metal plates.
The perforations for the admission air to "a" its exit from the lamp are of the
size allowed by law, and that part of the metal through which they are made forms
only a small portion of its bulk.

page_text: The cool air entering the lamp impinges against the extended part of d marked I
at inlet, and also against extended part of m, marked o, and o' in Figs 1 and 5, and so
condenses the heat which has been conveyed to them from other parts of their bulk.
The extensions of d, marked 1 Fig. 1 and of m, marked o, o¹, Figs 1 and 5, have
holes bored in them to allow of the free passage of air to the "gauzes," and cap
respectively.
The plates g, g, and l, l, have the same functions, those marked g, in case of
overheating, melt and cut of the air supply, and those marked 1, cut off the outlet
of the products of combustion under like conditions.
Figs 1, 4, 5 & 8, show at j, the position and arrangement of an argand burner as
applied to a safety lamp, the method of the air supply, and of operating the wick;
the arrangement of tube i, permits the use of a very short burner.
The star wheel which operates the wick is fixed upon a compound spindle u, v, w,
having a thumbscrew 8, outside, The parts u, v, are sorrounded by an airtight
gland or sleeve t, passing through both walls of the lamp, and preventing its being
unscrewed, and secured in position by a catch or spring not accessible until after
the part u, has been withdrawn.
The part is held within the gland or sleeve by a stud projecting from.the
inside, traversing a corresponding circular groove joined to a spiral one in the
spindle.
The part u cannot be rotated except in the direction of the grooves, the annular
one being for the purpose of raising or lowering the wick but the spiral groove
only permits the movement that lowers the wick, while the spindle is being with-
drawn from the sleeve, this action draws the wick down into the tube, extinguishing
the light before the part u can be withdrawn, or the catch fastening the sleeve can
be reached.
Having now particularly described and ascertained the nature of my inven-
tion, and in what manner the same is to be performed, I declare that what
I claim is
1st The use of air ports at a tangent or other angle than the radius, to circular
inner face of the outer wall of a safety lamp, as hereinbefore described and as
illustrated.
2nd In safety lamps, the use of a metal flue uniting a diaphragm near the top of
the lamp, with another diaphragm, or cover of flame chamber, and surmounted by
a cap.
3rd The use of conducting metal plates with large surfaces for condensing heat,
united to and forming one piece with those portions of the same that are perforated
to allow the passage of air to or from a safety lanp, in place of the usual gauze of
wove wire.
4th The use of compound or sandwich metal plates perforated to allow the air to
pass to or from a safety lamp, in place of the usual gauze of wove wire. The front
of such plates being more fusible than the back.
5th In a safety lamp the use of a round or argand burner surrounded by a glass
chimney, in combination with the spindle u, v, w, for actuating the wick and
preventing the lamp being opened without first extinguishing the flame.
6th In safety lamps, the admission of air to the centre of the burner (as above
described) by means of a tube passing through the oil vessel, substantially as
herein before described and illustrated.
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