IMPROVEMENTS IN MINERS' LAMPS
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by the said Evan Evans at the Office of
the Commissioners of Patents on the 24th November 1883,
EVAN EVANS of Llanrwst in the county of Denbigh IMPROVEMENTS IN
MINERS' LAMPS
"
This invention has for its object a miner's lamp that will be automatically.
extinguished by the aid of the gas itself before the lamp becomes heated sufficient
to cause an explosion. My lamp body can be of any convenient construction but
round the gauze portion I place a metal cylinder, preferably tin, which is held up
by a lever or catch so that there is good ventilation and air supply to the lamp.
The moment however that the lever or catch is let go, the cylinder falls and cuts
off both supply and exit, thus acting as an extinguisher. The catch or lever is
kept in position by a wire or rod, having a joint or link of fusible metal or other
material incapable of standing great heat. The wire or rod and link is placed in
the lamp chamber near the gauze, so that if a flame plays on the inside of the gauze
it immediately attacks the joint or link and the cylinder falls. The wire or rod is
of course attached below to a fixed point so that nothing but the destruction of the
joint can cause a break of continuity. A locked cover over all with apertures for
light and rings of perforations for air, completes the lamp. This cover is fixed on
by a bar passing up through it and locked on the outside by a padlock or other
special lock. The advantage of this lamp extinguisher is that it being outside the
lamp it not merely prevents air getting to the lamp and so extinguishes the light,
but it shuts off the admission of the inflammable gas to the lamp and hot lamp.
gauze, and for a moment or two after the extinguisher falls allows the flame to
continue till the oxygen in the lamp is consumed and thus leaves a few moments of
light to assist the miner in escaping. Another advantage in this lamp is that there
is a metal casing protecting the gauze so that the latter cannot.be hurt either by
accidental knock or by design. Also the air entering at the bottom of the cylinder

page_text: and passing up between the cylinder and the gauze creates an upward current over
the surface of the gauze and so greatly diminishes the tendency of the gauze
meshes to get clogged up with coal dust.
In some cases to still further increase this current, I place an opening below the
lamp covered with gauze, which is also covered by the cylinder when it falls on
the string or link becoming destroyed.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Evan Evans in the Patent Office on the 24th May 1884.
EVAN EVANS of Llanrwst in the county of Denbigh, "IMPROVEMENTS IN
MINERS LAMPS
"
"
This invention has for its object a miner's lamp that will be automatically
extinguished by the aid of the gas itself before the lamp becomes heated sufficient
to cause an explosion.
This invention is best described by aid of the accompanying drawing in which
A is the oil chamber, B wick tube, C usual wick raiser passing through the oil
chamber by means of a special tube surrounding it as shewn. D. D. body or
framework of lamp constructed of metal. E. E. glass cylinder. FF wire standards
tying D D together. G Gwire gauze. Hmetallic cross piece supported on three
bars I I I carrying lever apparatus, J disc assisting in holding this in place, and
also preventing a direct upward or downward draught. K stem carrying this disc,
and locked into case by link passing through hole L and locked by padlock,
M cylinder supported on lever N. N lever kept in position by rod O, which is
secured by link of fusible metal or combustible material P to a fixed support or
catch Q. In order to support the cylinder M, the following arrangement may be
substituted for the foregoing one. The rod O may be carried up straight to the
under side of top of cylinder, which it pushes up to the proper height. The wire Q
continued straight down from the bend at the end of same to bottom frame of lamp
and rest on a place fitted to recieve it. ☐ and Q may be connected as before by
the link P. But in order to hold up O against the cylinder, the link will be
pressed by Q against the other bend in O. The fusible link P is placed close to
the gauze so that if a flame begins to play on the inside of the gauze, it shall melt
the link, and allow the cylinder M to fall, and thus close all air ingress to and
egress from the combustion chamber of the lamp without however putting out the
flame immediately: The latter will burn on a trifle longer thus helping the mineř
to find his way out into the main heading. The link can be of silk, cotton, twine
or any other material that will easily burn instead of fusible metal.
The mode of action is as follows; Air enters at R follows the course of the
arrows escaping at top, a part however finds its way through the gauze, feeds the
Hame, and escapes at top. In some cases I prefer to close the orifice R and 'admit
the air to the casing by a special entrance S, shown in dotted lines. This entrance
is connected by tubing to a source of pure air, or a tube is suspended from it, so as
to draw air from near the ground where it is purer than above.

page_text: Having now described the invention, and the best mode known to me of carrying
it into effect, I wish it to be understood that what I believe to be new, and desire
to protect under the Letters Patent is :-
1. The manufacture of lamps constructed and arranged substantially as, and for
the purposes herein described, also the following parts of the invention taken
separately, each substantially as and for the purposes described.
2. The cylinder M enclosing a large air space, and suspended by an easily fused
or easily burned connection P, placed near the wire gauze on the inside in such
manner that if gas begins burning in the inside, the link shall be destroyed, and
thus the connection shall be broken, and all intercourse between the lamp
combustion chamber and the outside air shall be cut off.
3rd. The application in safety lamps of a link capable of being destroyed by heat,
placed in juxta position to the gauze in such manner that if gas ignites inside the
gauze it shall destroy the link, and without immediately putting out the light, cut.
off all communication between the flame and the outside air.
In witness whereof I, the said Evan Evans have hereunto set my hand and seal
this Twentieth day of May in the year of our Lord one thousand eight hundred
and eighty four.