Improvements in Miners' and like Safety Lamps.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements in Miners' and like Safety Lamps.
I, THOMAS GIRDWOOD MACFIE, of 5, Grosvenor Road, Westminster, in the
County of London, Agent, do hereby declare the nature of this invention to be
as follows:-
The object attained is the making and burning of acetylene gas in safety
lamps for mining and other operations in which the use of a naked light is
dangerous.
The lamp consists of (1) a carbide of calcium chamber (2) the body of the
lamp and (3) the water holder.
The lamp consists of (1) a carbide of calcium chamber (2) the body of the
lamp with an air tight joint. In the centre of this chamber there is fixed a per-
pendicular column or cylinder of porous materials.
The body of the lamp consists of a metal bottom fitted with a burner in the
centre, and having holes in the side filled with iron wire gauze to permit the air
to enter freely to the flame. To this bottom there is fastened so as also to be
air tight a stout circular glass surrounding the flame, and to that again there is
fastened so as to be air tight an upper cylinder made of iron wire gauze closed at
one end and in all respects similar to the iron wire gauze cylinders at present
in use in safety lamps. The bottom is domed with an aperture to permit the gas
to rise through the burner. This burner is constructed to permit only such an
amount of flame as will be extinguished by an explosion in the space within the
glass and wire gauze cylinders. The dome is filled with asbestos or any similar
material. Through this bottom there also runs a pipe terminating so that water
from it will fall on the top of the porous column or cylinder in the carbide of
calcium chamber, and so constructed by contractions or obstructions that water
can pass from it in drops only at intervals proportionate to the amount of gas
desired to be generated. This pipe connects with the water holder fixed on the
top of the body of the lamp, and by turning a tap in it water is allowed to per-
colate through the pipe and fall on the porous column or cylinder already
mentioned.
The top end of this pipe should be covered by a fine metal wire gauze. The
lamp is also furnished with one tap by which the gas can be turned off from the
burner and with another which can be opened to allow the gas to escape into the
open air.
The water holder is also fitted with a top to unscrew to permit the holder to
be filled, and this top is perforated so as to allow the escape of any gas which
inay ascend through the water tube.
The lamp is held together by pillars from the bottom of the body of the lamp
to the water holder, and one of these pillars is used as the water pipe in question
being prolonged so as to terminate over the porous column or cylinder in question.
Dated this Twenty-second day of November 1898.

page_text: improvements in miners and like Safety Lamps.
I, THOMAS GIRDWOOD MACFIE, of 5, Grosvenor Road, Westminster, in the
County of London, Agent, do hereby declare the nature of this invention and
in what manner the same is to be performed to be particularly described and
ascertained in and by the following statement:-
This invention relates to improvements in miners and like safety lamps and has
for object to construct lamps of that class, in which acetylene gas can with safety
be generated and burned as illuminant in all cases where it is dangerous or
inexpedient to use a naked light.
In order to render my invention more readily understood I have hereunto
sttached a sheet of drawings illustrating the construction and arrangement of
parts as applied to a miners safety lamp, the outward conformation and general
structure of such lamps as now in common use being in the present case followed
as closely as practicable. It will be understood that I do not intend to confine my-
self to the form of construction illustrated in the drawings, but may employ
other methods of similar or corresponding character to attain the same end.
My new or improved lamp essentially consists 1) of container a intended to
receive a charge of carbide of calcium sufficient for the generation of acetylene
gas required for providing a brightly burning light of convenient candle power
for a certain predetermined number of hours, 2) the lamp frame composed of
Hanged annular sockets s, upright supports g, glass cylinder e, and wire gauze
mantle f, and 3) gauze protector screen and water reservoir combined in one
and marked h w.
The carbide container a is adapted to be airtightly attached to the lamp frame
by means of screw threading as shown in the drawing or in other suitable and
efficacious manner so as to form the base or bottom portion of the lamp. In the
centre of container a there is provided a vertically rising porous column or
cylinder a secured to the bottom plate of the container a and left open at the
top. The said cylinder, of suitable diameter and length is made of porous
material perforated metal or the like, through which the water supplied from
water chamber w through tube twill percolate into the carbide in container a.
A circular plate b, having a downwardly extending and outwardly screw-threaded
annular flange by means of which it can be gas-tightly secured in frame sockets,
is provided to form the cover plate of the gas generating carbide container, and
has in its centre a dome b' furnished in its apex with an aperture for the recep
tion of burner d. The hollow of dome b' is filled with a light packing cof
asbestos or the like held in position by a conveniently attached plate or cap cl
made of wire gauze, perforated metal or similar open material so that the gas
can freely pass from the generator into burner d. The packing c serves to filter
the gas and to prevent the flame from striking back into the generator.
The water chamber w is arranged in the form of a jacket around gauze mantle
protector and can be filled through a suitably placed neck in its top plate,
which aperture is adapted to be closed by screw plug or cap w¹, or in other con-
venient manner. The said screw plug has one or more minute bores through
which air can freely enter the water chamber as required, and any gas having
found its way into the water chamber may readily escape into the open air.
From the lowest level of the water chamber w, a tube t, provided with hand
operated tap for turi ng on or shutting off the water supply, is conducted
downwards and its end tightly packed or otherwise secured in a bore passed
through frame socket s, while the continuation of aforesaid tube t is so bent
as to enter the central cylinder a¹ of container a when the latter is placed and

page_text: secured in position. The bent tube 2 is preferably made to screw into the lower
portion of the bore in frame socket s so that it may temporarily be removed in
order to admit of unscrewing the domed plate 6 for the purpose of cleaning the
glass cylinder and gauze mantle as in the present safety lamps. The lower
extremity of tube t2 is contracted or throttled, or, as shown in the drawing, pro-
vided with a suitable attachment t³, for the purpose of allowing only a certain
limited quantity of water to pass in a given space of time.
An inner cover i may be fitted in the carbide chamber a, having a central
aperture to enable the bent tube to enter cylinder a¹ and admit of the gas
rising towards the domed plate 6 and burner d.
The lamp is further provided with a hand operated tap by which the gas can
be turned off from the burner, and a second tap which when opened, will allow
the gas to escape from the generator into the open air. Both last mentioned
taps are not shown in the drawing and may be affixed in any convenient manner
and position. Both taps may also be coupled in suitable fashion so that with one
manipulation the one tap may be opened and the other tap be closed simul-
taneously.
Having now particularly described and ascertained the nature of this
invention and in what manner the same is to be performed, I declare that what
I claim is:-
1) In miners and like safety lamps the generation and use of acetylene gas in
the place of other illuminants now in use.
2) In miners and like safety lamps as claimed under 1), the construction and
arrangements of parts for the purpose of safely generating and burning acetylene
gas and regulating the influx of water into the calcium carbide container, sub-
stantially as set forth and illustrated in the accompanying drawing.
3) In miners and like safety lamps as claimed under 1) and 2), the arrange-
ment of the water reservoir around the upper portion of the lamp in the shape of
a water jacket so as to form, and act as, a shield for protecting the safety gauze
mantle, substantially as described and shown in the accompanying drawing.
4) In miners and like safety lamps as claimed under 1) and 2) the regulating
of the water supply to the carbide container, by means of a fixed contraction
of the supply tube in the interior of the lamp and out of reach of interference
the lamp is in use, substantially as set forth and illustrated in the
whilst
drawing.
Doted this 22nd day of August 1899
CAMBIE & WINCKELSETT,
For the Applicant.