MINERS' SAFETY LAMPS
Year: 1884

page_text: We, JOSEPH ROUTLEDGE of Sunderland in the County of Durham and HENRY
JOHNSON of Sunderland in the County of Durham, Colliery Manager and Master
Smith do hereby declare the nature of our invention for
MINERS' SAFETY LAMPS" to be as follows:-
"IMPROVEMENTS IN
Our invention relates to safety lamps used by miners in places liable to the
presence of explosive gas in dangerous quantity, and it has for its object a novel
method of constructing such lamps so that great safety is obtained from two lamps
being practically combined in one; they are not liable to accidental or other injury;
are extinguished if carburetted hydrogen, coal gas, or firedamp be present, or if
they are accidentally placed in a horizontal position, or are wilfully tampered with
in order to open them; whilst their illuminating power is excellent and sufficient
for every purpose required in mining.
Our improved lamp consists of a lower oil vessel of brass, block tin, or other
suitable material, supplied with colza or other suitable oil, and provided with a flat
wick tube and wick and a wick pricker of the usual kind passing through the
vessel. The top of the lamp is screwed upon the upper part of the oil vessel by an
ordinary screw thread, and is provided with a screw lock or lead rivet to prevent
it from being wrongfully removed.
Above the oil vessel round the flame is arranged a vertical wire gauze cylinder
or conical tube, closed at its narrower upper end which extends nearly to the top
of the lamp, and arranged so that it can be readily removed for examination and
replaced when desired. Round the lower part of this conical cylinder is fitted a
transparent glass cylinder extending about half way up the exterior part of the
lamp, and held down by an annular ring or plate surrounding the gauze cylinder
and pressing upon the upper edge of the glass cylinder, the plate being held in
position by a sufficient number of small vertical columns round it.
Above this plate is fitted a second vertical cylinder or conical tube of wire gauze
surrounding the inner one but leaving an annular space between them. The lower
end of this outer gauze tube is screwed or fits into a rim or flange upon the upper
side of the plate, whilst its upper end a short distance above the top of the inner
tube is covered by a wire gauze cap.. Surrounding the outer wire gauze tube last
described, but leaving a space between them, is an outer cylinder of tin plate or
other suitable material serving as a protector and air regulator,
'

page_text: This cylinder also rests upon the lower plate and extends up to the top of the
lamp, the whole being fixed together in position by a sufficient number of vertical
bolts or rods and surmounted by a brass or other domed cover and a handle.
Near the lower part of the outer protecting cylinder are a sufficient number of
holes through which air enters to support combustion, passing thence through the
outer gauze and down between it and the inner gauze through openings left in the
plate which embraces the latter, into the space between the inner gauze and
the glass cylinder, and thence through the inner gauze to the flame.
The products of combustion pass up the inner gauze cylinder, then through it
and the outer one, and escape by openings in the outer protecting cylinder. If any
portion of the novel safety lamp described be injured, the lamp will still be safe;
and should either the exterior or the interior wire gauze be injured the lamp will
still be safe whilst one remains whole.
It will be seen that our invention consists of the combination of the inner wire
gauze cylinder closed at its upper end, the glass cylinder surrounding its lower
part, the annular plate above the glass cylinder, the outer wire gauze cylinder
surrounding the inner one and by a wire gauze cap, and the outer perforated
protecting cylinder, all arranged and connected together in the manner described.
The lamp as described may be made of any desired dimensions.

page_text: We, JOSEPH ROUTLEDGE, of Sunderland, in the County of Durham, and HENRY
JOHNSON, of Sunderland in the County of Durham, Colliery Manager and Master
Smith do hereby declare the nature of our invention for "IMPROVEMENTS IN
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 and
accompanying drawing:-
Our invention relates to Safety Lamps used by Miners in places liable to the
presence of explosive gas in dangerous quantity, and it has for its object a novel
method of constructing such lamps, so that great safety is obtained by means of
two lamps being practically combined in one; the liability to danger from accidental
or other injury is reduced or prevented; the lamp is extinguished if carburetted
hydrogen, coal gas, or firedamp be present, before the naked flame can be exposed,
or if the lamp be wilfully opened or tampered with; whilst its illuminating power
is excellent and sufficient for every purpose required in mining.
The accompanying drawing is in illustration of our invention, figure 1 being a
longitudinal section of a lamp, figure 2 a similar section and figure a plan of the
central flanged protecting tube, figure 4 a longitudinal section and figure 5 a
horizontal section of the upper protecting tube or air regulator. The same letters
of reference indicate the same parts in the several figures.
a is an oil vessel of the ordinary kind, of brass or block tin, supplied with the
best colza oil or other suitable illuminating fluid, and having a flat or cylindrical
wick pipe and wick supplying the flame at b, and a wick pricker c of the usual
kind, which passes up through the oil vessel a.
The whole of the top or upper part of the lamp is screwed upon the oil vessel a
by an ordinary screw thread at d, and is locked in the usual way when in its place
by a screwlock or lead rivet as shown. In this lamp top is arranged a central
conical tube or cap e of wire gauze of the proper wellknown kind to prevent the
passage of flame through it. This gauze tube or cap rises to within a short
distance, preferably about three quarters of an inch, of the top of the entire lamp.
Outside and surrounding it is fitted a protecting tube f of brass, tin, or other
suitable metal or material, occupying about the centre part of the lamp in height
having a flange at or near its lower edge at g, this flange being perforated with a
number of holes, as shewn in figure 3, to allow a sufficient quantity of air to pass
down to keep up the necessary supply to the flame at b.
The lower part of the lamp top round the flame is composed of a strong glass
cylinder h fitted within a frame of brass or other metal, and a second outer wire
gauze tube or cap k is arranged outside the conical protecting tube f the upper end
of this tube k reaching to the top of the entire lamp, whilst its lower end is flanged
out and is firmly held between the top of the glass cylinder h and the frame which
secures the latter in position at i. Outside the last described wire gauze tube or
cap k is fitted a protecting tube of tin, brass, copper, or other suitable metal or
material, and this tube serves as an air regulator, its upper end reaching to the
top of the entire lamp whilst its lower end is either adjusted at a short distance
above the frame i, as shewn, or rests upon the latter but is perforated with holes.
The flange g of the tube f is also held between the top of the glass tube h and the
frame i, the whole being firmly supported and held together by small brass or iron
poles, and surmounted by a brass or other tile and ring handle at m.
The flame at 6 receives its supply of air through the holes or space at the lower
end of the tube and through the wiregauze k, thence down through the holes in

page_text: the flange g into the space between the glass tube h and the inner wire gauze e,
and through the latter to the flame b (as shewn by the arrows). The products of
combustion pass straight up (as shewn by the central arrow) and escape through
the tops or caps of the interior and exterior wire gauges e and k through holes in
the protecting cylinder or directly through the top of the lamp at m
The lamp constructed as described and shewn is at once extinguished if any
carburetted hydrogen, or firedamp be present.
It will be seen that if any single part of the lamp be injured by a workman
whilst at work the lamp still remains safe. If for instance, either the exterior
parts or the interior wiregauze e be injured separately the lamp retains its safety.
If the lamp be opened wilfully by any one using it no explosion can take place,
for if gas is present in dangerous quantity the light is extinguished by it before
the naked flame can be exposed, and our improved lamp is especially valuable in
such cases.
The part of the lamp opposite the flame b consisting of a single thickness of
glass h and wire gauze e, its illuminating power is excellent and sufficient for all
mining purposes.
We do not confine ourselves to the precise form and proportions of the several
parts of the improved lamp, which may be varied more or less to suit varying
circumstances, and the lamp itself may be made of any desired size, but having
now particularly described and ascertained the nature of our said Invention and
in what manner the same is to be performed, we declare that what we claim is:-
.
The combination of the interior wiregauze e, exterior wire-gauze k, glass
cylinder h, and tubes f and l, substantially as and for the purpose described and
shewn in the drawing.
Dated thi, n0th day of October 1001
EDWARDS & Co.,
Agents for the Applicants.