Miners' Safety Lamp.
Year: 1894

page_text: Date of Application, 19th Nov., 1894-Accepted, 29th Dec., 1894
Miners' Safety Lamp.
I, CARL DAHLMANN, of 35 Neustrasse, -Herne, Westphalia, Germany, Engineer,
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 an improved construction of miners safety lamp in which
the air supply is so arranged that the flame is extinguished when owing to the
presence of inflammable gases in the workings an explosion ensues within the
lamp.
The construction is shewn on the accompanying drawing which shews an elevation
of the lamp. As will be seen, the products of combustion from the lamp flame
escape through the chimney e which is surrounded by the wire gauze casing a.
At the side of the chimney is arranged the device for the supply of the air required
for combustion.
This consists of a tube 6 situated within the glass cylinder, and leading down to
the flame where it has an oblique opening. The tube has its lower part enclosed
by a wire gauze covering f while the upper end of it is also enclosed by a wire
gauze hood C9 which is again enclosed by a cap g.
The air enters at the lower edge of the latter as indicated by the arrows and
passes through the wire gauze hood c and through the tube b and wire gauze f to
the flame.
The air passes from the opening & both above and below the flame. As the air
becomes more or less heated on its transit through the above mentioned channels
which take up heat both from the flame and the products of combustion, the
luminosity of the flame is correspondingly increased thereby.
Should an explosion occur in the tube b, then owing to the wire gauze c and cap g,
a back pressure will occur causing both the flame in the tube b and the flame of the
lamp to be extinguished.
In most cases however the flame of the lamp will be extinguished before the
explosion can occur, such extinguishing taking place with a peculiar loud sound.
The cap 9 also serves as protection to the wire gauze hood against being
obstructed by impurities, and it insures a quiet flame with strong draught. The
cap can also be made adjustable for the purpose of regulating the illuminating
capacity of the lamp or for entirely cutting off the air supply in case of need; in
the latter case the flame of the lamp or any burning gases in the wire gauze
covering will at once be extinguished.
The cap 9 can also be entirely dispensed with, as the protected inlet tube will of
itself afford sufficient security for the extinguishing of the flame on the occurrence
of danger.
The upper part of the lamp may advantageously be more or less enclosed by a
covering that will accelerate the air supply, which will have a cooling effect on
the covering c.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. In a miners safety lamp, effecting the air supply to the flame by means of an
inlet tuho such a1

page_text: rovering, in order thereby to produce a back pressure on the occurrence of an
explosion within the lamp, and thus to effect the extinguishing of the flame,
substantially as described.
2. In a miners safety lamp, such as is referred to in the first claim, the use of a
protecting cap such as 9 enclosing the upper wire gauze covering, for the purpose
of assisting the production of the back pressure on the occurrence of an explosion,
such cap being either fixed or adjustable for regulating or cutting off the air supply,
substantially as described.
3. The improved miners safety lamp combined and operating as herein described
with reference to the drawings.
Dated this 19th day of November 1894.
ABEL & IMRAY,
Agents for the Applicant.