Improvements in and relating to Miners' Safety Lamps.
Year: 1890

page_text: Date of Application, 16th Jan., 1890
Complete Specification Left, 16th Oct., 1890-Accepted, 22nd Nov., 1890
PROVISIONAL SPECIFICATION.
Improvements in and relating to Miners' Safety Lamps.
We, JOHN DUNCAN, Watchmaker, of 46 Stirling Street, Airdrie, and ROBERT
MCLAREN, Her Majesty's Inspector of Mines, Uddington, both in Lanarkshire, do
hereby declare the nature of our invention to be as follows:-
This invention has reference to and comprises improvements in the construction, or
arrangement and combination of the parts of miners safety lamps, which will make
such lamps give a better light with greater safety and less liability to the light going
out, with a more perfect mode and means of regulating the supply of air to the flame
of the wick to support combustion, and enable them to burn cheaper and safer oils
than those generally heretofore in use.
The lower part or basement of this lamp would consist of a hollow cylindrical
shell, having the oil lamp proper screwed up into this from below, in the form of
a short cylindrical vessel, the lower part of which forms the oil reservoir, and
would be rather less in diameter than the internal part of the hollow cylindrical base,
but having a rim flange at the extreme base, leaving a narrow annular space or
holes above it for the air to enter and pass up the narrow space between the outer
case and the oil vessel and over the latter to support combustion, radial divisions or
vanes steadying the oil vessel in this position. The upper part of the outer case
would have screwed into it a cylindrical hollow chamber, up through a close tube in
the centre of which the wick tube would pass from the oil vessel below and project
an inch or so into the flame cone secured round it on the upper surface, preferably
screwed into the centre of the upper plate of the oil vessel, so as to be removed with
it when it was screwed out. This wick tube would preferably be made to carry a
flat wick, but it might be a circular or annular wick. The oil vessel would have a
usual hole and liquid tight cover over it for filling in the oil all enclosed, and be
locked to the outer case much in the usual manner of some other forms of miners'
safety lamps, and fitted so that whenever the lamp was unlocked and removed it
would put out the light; or otherwise the improved arrangement for letting in the
air to the light would be shut off by the removal of the oil vessel and its wick,
and so extinguish the flame before it could be removed. The air would be admitted
through radial ports fitted in a swivelling disc and fixed disc between the close
central tube and the outer cylindrical chamber carrying the gallery and wick cone,
just over the oil vessel where the air enters to pass through the radial ports. A little
above the fixed radial ported disc, a wire gauze disc would be secured, to spread the
air up through the gallery plate supporting the flame cone, inside the usual close
short cylindrical glass for giving the light out through the lamp, and which gallery
plate would be pierced with holes outside and inside the cone to allow the air to get
at the wick tube and flame both from the inside and outside of the flame cone.
moving lower air ported disc would have a finger lever passing out through a slot
in the upper part of the case so as to oscillate this disc to regulate the amount
of air admitted to the lamp which might be secured either by the friction of a
spring or spring notch to fix it in the proper position. This air admission disc with
its lever would be so fitted as to shut off all air from the lamp and extinguish the
flame automatically before the oil vessel could be removed, that is by the act of
removing the oil vessel or unlocking it; and the air admitted to the lower annular
space between the oil vessel and the outer case might be arranged to pass through a
smaller outer wire gauze cylinder, so as to be able to see when any reversal of the
current took place, and prevent the possibility of light striking back through the
lamp. The said outer glass as in other lamps would be secured between the said
annular air vessel and gallery plate and a glass annular disc plate or plates above,
The

page_text: supported on six or more of the protecting wires of the glass preferably by a ring
of asbestos insertion, and which would carry the outer gauze cylinder secured to or
between the upper discs above the glass and light, and which gauze would be domed
above to allow of the escape of the waste products of combustion from the light up
through a central internal cone funnel made of sheet metal, or it might be glass, open
only at top, which would draw and conduct the waste gases to the top of the wire
gauza, where they would escape between this funnel and through the meshes of the
gauze, which as usual would be fine enough to prevent the flame from any explosive
gas in the pit passing out through the gauze to explode it. The lamp would be
carried in the usual manner by four or more wires, projecting up from the upper disc
to protect the wire gauze, and secured to the carrying top of the lamp.
In some
cases when desired, as in other forms of lamps, a corrugated or other outer protecting
case may be mounted outside the wire gauze open below and above to protect the
whole and yet allow of the free escape of the waste gases. Sheet asbestos or other
equivalent would however preferably be fitted on the underside of the top carrying
plate, and on the inside of the outer protecting plate, secured by wire or narrow strips
of metal to prevent the top of the outer case and of the wire gauze from getting over-
heated by the escaping waste gases from the flame; and this outer case might be locked
as in other lamps. In this way it will be seen that as the air is admitted to the light
from below, the current draws the flame upwards and makes a brighter flame than in
lamps, as heretofore constructed, in which the air is admitted through the upper wire
gauze, and makes a safer and more perfect current for the escape of the waste gases
from the light up through the internal funnel. But should any wind or draught by
any accident tend to blow the air in through the top wire gauze, the escaping products
of combustion would be immediately blown back, and put out the light before it couldi
strike back down through the air perforations in the gallery or cone of the flame
through the air inlet wire gauze below.
COMPLETE SPECIFICATION.
Improvements in and relating to Miners' Safety Lamps.
We, JOHN DUNCAN, Watchmaker, of 46 Stirling Street, Airdrie, and ROBERT
MCLAREN, Her Majosty's Inspector of Mines, Uddingston, both in Lanarkshire, do
hereby declare the nature of our invention, and in what manner the same is to be
performed to be particularly described and ascertained in and by the following
statement in writing, reference being had to the accompanying sheet of drawings, and
to the letters and figures marked thereon, that is to say :-
Our invention has reference to and comprises improvements in the construction of
the parts of miners safety lamps, which will make such lamps give a better light with
greater safety and less liability to the light going out, with a more perfect mode
and means of regulating the supply of air to the flame of the wick to support
combustion, and enable them to burn cheaper and safer oils than those generally
heretofore in use.
And in order that our said invention, and the manner of performing or carrying
the same into effect or practice may be properly understood, we have hereunto
appended an explanatory sheet of drawings in which the same reference letters are
used to indicate corresponding parts in all the figures where shown. Figure 1 is a
sectional elevation of a miners safety lamp constructed in accordance with our im-
provements and Figure 2 is a sectional plan view taken on the irregular line 1-1
in Figure 1. While Figure 3 is a sectional elevation of a modified construction of
burner and flame cone from that shown in the general view Figure 1.
Referring to these drawings -The lower part or basement of this lamp consists of
a hollow outer cylindrical shell A having the oil lamp properly screwed up into this
from below, in the form of a short cylindrical vessel B B the lower part B of

page_text: which forms the oil reservoir, and would be rather less in diameter than the internal
part of the hollow cylindrical base A, but having a rim flange B₁ at the extreme base,
leaving a narrow annular space or holes above it at B2 for the air to enter and pass
up the narrow space A" between the outer case A, and the oil vessel B and over the
latter to support combustion at the burner (, as indicated by the arrows in Figure 1,
radial divisions or vanes or other equivalent steadying the oil vessel B, in this
position. The upper part or shelf A¹ of the outer case A has a cylindrical hollow
close chamber A2 above it into which the air passes as hereinafter described. The
tube B₁ formed by the upper neck part of the oil vessel B, B', has screwed into it
at C, the wick tube C which passes from the oil vessel B below and projects an inch
or so into the flame cone C, secured round it on the upper surface. This wick tube ()
is preferably made to carry a flat wick w but it might be a circular or annular wick.
The oil vessel B is formed with a central hole and screwed neck B¹ over it through
which the oil can be filled all enclosed, and locked to the outer case much in the usual
manner of some other forms of miners' safety lamps, and fitted so that whenever the
lamp was unlocked and removed it would put out the light; or otherwise the im-
proved arrangement for letting in the air to the light would be shut off by the
removal of the oil vessel B, and its wick w, and so extinguish the flame before it
could be removed. The air would be admitted through radial ports D', formed in
a disc D swivelling on the lower part of the neck B' and in a fixed disc D² screwed
between the close central neck B₁ of the oil vessel B, B', and the outer cylindrical
chamber A carrying the wick tube and cone C, 0, just over the oil vessel B
where the air enters to pass through the radial ports D. A little above the fixed
radial ported disc D2 and ports D¹ a wire gauze disc D³ is secured within its upper
rin to prevent the flame striking back and to spread the air through the close
chamber A2 and distributing flame cone C², inside the usual close short cylindrical
glass E for giving the light out through the lamp; and the lower part of the
cone C is pierced with slits or holes at C, to allow the air to get at the wick and
flame both fron the inside and outside of the flame cone (2. In some cases, as
shown in Figure 3, the cone burner C² may be fitted with an internal central netting
of wire gauze C³ between the wick tube C and the outer case (2 through which the
air would pass to the flame of the burner, and prevent the flame striking downwards
into the air chamber A2: The moving lower air ported disc D, has a finger lever or
pin D passing out through a slot in the upper part of the case A, so as to turn or
oscillate this disc D, to regulate the amount of air admitted to the lamp through the
ports D¹ and the wire gauze D³, and be secured by a screw at the inner end of pin or
it might be by the friction of a spring or spring notch to fix it in the proper
position. This air admission disc D, D', with its pin or lever D", is so fitted as to
shut off all air from the lamp and extinguish the flame by the hand lever D" or
automatically before the oil vessel B could be removed, that is by the act of removing
the oil vessel or unlocking it while the lever D" was in place; and the air admitted to
the lower annular space B² between the oil vessel B and the outer case A might be
arranged to pass through a smaller outer wire gauze cylinder, so as to be able to
see when any reversal of the current took place, and prevent the possibility of light
striking back through the lamp. The outer glass E', as in other lamps is secured
between the said annular air vessel A2, on an asbestos ring in the screwed in gallery
plate E, and an asbestos ring on an annular removable disc ring plate E2, above fitted
in the outer gallery ring E³ supported on five or more of the protecting wires E¹¹ of
the glass E, and which carry the outer gauze cylinder F secured by asbestos rings
to or hetween the upper discs E2 E3 above the glass E' and light, and which gauze
is domed above at Fi to allow of the escape of the waste products of combustion
from the light up through a central internal cone funnel F2 made of sheet metal, or it
might be glass which would draw and conduct the waste gases to the top F¹ of
the wire gauze, where they would escape between this funnel F2 and through the
ushes of the gauze F, as indicated by the large arrows in Figure 1, which as usual
would be fine enough to prevent the flame passing through it to any explosive gas
outside, in the pit to explode it. The lamp is carried in the usual manner by four or

page_text: more wires E' screwed to and projecting up from the upper disc E³ to protect the
wire gauze, and secured to the carrying hook and top at F of the lamp. In some
cases when desired, as in other forms of lamps a corrugated or other protecting case
may be mounted outside the wire gauze F and either outside or inside the rods E4
open below and above to protect the whole and yet allow of the free escape of the
waste gases. Sheets of asbestos F³ or other equivalent are preferably screwed or fitted
on the underside of the top carrying plate Fi, above the wire gauze F to prevent the
top of the outer case and of the wire gauze from getting overheated by the escape of
waste gases from the flame. In this way it will be seen that as the air is admitted
to the light from below, the induced current draws the flame upwards towards the
cone F and makes a brighter flame than in lamps, as heretofore constructed, in
which the air is admitted downwards to the flame through the upper wire gauze, and
makes a safer and more perfect current for the escape of the waste gases from the
light up through the internal funnel F. But should any wind or draught by
any accident tend to blow the air in through the top wire gauze F, the escaping
products of combustion would be immediately blown back through the funnel F2,
and put out the light before it could strike back down through the air perforations in
the cone of the flame and down through the inlet wire gauze D³ below.
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is :-
:-
First. The construction or arrangement and combination of the parts of a miners'
safety lamp with air supply and safety fittings below the flame and burner,
substantially as herein described, in reference to and shown in the accompanying
drawings.
Second. In a miners' safety lamp, the mode and means of admitting air to tl
burner and flame from below consisting of an air space and chambers and wire
gauze and regulating discs, substantially as and for the purposes herein described, in
reference to and shown in the accompanying drawings.
Third. In a miners safety lamp, the construction and use of a wire gauze disc or
diaphragm carried in a fixed ported or hollow disc or equivalent air supply support
below the flame and burner, substantially as and for the purposes herein described, in
reference to and shown in the accompanying drawings.
Fourth. In a miners' safety lamp, the construction and use of a fixed ported disc,
with a wire gauze disc above it, in combination with a movable or oscillating ported
regulating disc, substantially as and for the purposes herein described in reference to
and shown in the accompanying drawings.
Fifth. In a miners' safety lamp, the production of an induced upward current by
admitting the air through a wire gauze diaphragm below the flame in combination
with a cone or funnel above, substantially as and for the purposes herein described, in
reference to and shown in the accompanying drawings.
Dated the 15th October 1890.
W. R. M. THOMSON & Co.,
96, Buchanan Street, Glasgow, Agents.