Improvements in Miners' Safety Lamps.
Year: 1892

page_text: Date of Application, 17th Nov., 1892-Accepted, 17th Dec., 1892
Improvements in Miners' Safety Lamps.
I, CARL HEINRICH WOLF of Zwickau in the Kingdom of Saxony, Manu-
facturer, 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 miner's safety lamps and consists in
providing same with a protecting shield or shields and with an igniting device
which can be operated from outside.
The object of the protecting shield is to enable the lamp to be used in the
most violent current of fire damp without there being the least risk of the
gauze getting so heated as to ignite any fire damp which may come in contact
with same.
The purpose of the igniting device is to enable the lamp to be ignited from
the outside without its having to be opened.
A safety lamp constructed according to this invention when put to a test in
an explosive gas mixture travelling at the rate of 50 metres per minute, showed
in no single instance any breaking of the mixture through the gauze cylinder.
This security is obtained by the protecting shield which encircles the gauze and
which is provided with projecting wings which destroy the force of the current
of fire damp and direct it through slots into the lamp. A protecting ring
provided with similar wings and slots or openings and allowing of the passage
of air to the flame from underneath the burner, may also be arranged on the
upper part of the lamp cistern.
To clearly explain the nature of my invention reference is made to the accom-
panying drawings in which :-
Figure 1 is partly an elevation and partly a section of one form of safety
lamp containing my improvements.
Figure 2 is a plan of same on line x-x of Figure 1.
Figure 3 is a similar plan on line y-y of Figure 1.
Figures 4 and 5 are respectively sectional views of one form of my igniting
device and of a modification of such form.
Figure 6 is a section of that side of the frame casing of the igniting device
carrying ratchet teeth, the operation of which is hereafter described.
The protecting shield a encircles the usual wire gauze cylinder of the safety
lamp which may be single or double as desired. The shield in the form iilus-
trated consists of a mantle preferably formed of corrugated or bent sheet iron
which is pierced with rows of slits. These slits are formed by making suitable
cuts in the shield, and bending outwards the wings or tongues formed by such
cuts. By this arrangement the rushes of air or fire damp coming against the
shield, are split and deflected by the wings or tongues and by the angles c
of the shield a so as to reduce the force of same and thus render it impossible
for the fire damp to break through the gauze to the flame.
A protecting ring or mantle with similar wings and slots or openings can be
arranged above the lamp cistern d and will allow of the passage of the necessary
air for combustion to the burner of the lamp. This air passes as shown in
Figure 3 through the openings e of the shell and through the single or double
gauze ring before it reaches the flame, so that the light remains steady under
all conditions. The protecting ring e for the inlet of the air can however if
required be dispensed with.
The protecting shield a and the ring e serve the further purpose of considerably
weakening, if not removing altogether the effect of the impact of air or gas
passing from inside to outside, and, in this way the re-igniting of the lamp in

page_text: case it should have been extinguished, cannot be the cause of an explosion of
the outside fire damp owing to the ignited mixture within the gauze cylinder
breaking through and coming in contact with such fire damp.
within the lamp
The igniting device which is placed in a sort of casing
cistern d consists of an outer casing or shell which serves for holding and
guiding an adjustable box carrying the igniting strip 7. The end of this
igniting strip is drawn upwards through slots in the end wall of the box k or
through the space left by this wall being removed and passes on with its under
side against the ratchet teeth m on the side of the casing i.
A pawl or friction link n bears against the front surface of the igniting strip 1,
which is provided with igniting primers or caps p, placed at suitable distances
apart and is enclosed in the box k which can be reciprocated within the casing i.
This friction link n is also provided with teeth on its end, of such form that
when the box k is drawn down by the stem o (which is provided with a knob or
button, and passes through the bottom of the lamp cistern) the friction link or
pawl n is made to pass over a primer or cap of the strip without the latter
following such movement of the pawl since it is held stationary to the wall ¹ by
the ratchet teeth m. An ignition of the cap thus takes place the strip is ignited
and on the stem o being released is moved upwards while burning, for a distance
corresponding to the distance of two primers or caps such movement being
automatically effected by the springs working against the box k; in this way the
lamp wick which is in the immediate vicinity, is ignited.
The springs can have the form shown in Figure 4 or be a simple spiral spring &
as in Figure 5 but it can be dispensed with altogether if required, in which case
the box with the burning igniting strip must be pushed upwards by the stem o.
When moving upwards with the box, the burning igniting strip, is held by the
teeth of the friction link or pawl n so that it must pass upwards, the direction of
the ratchet teeth being such that no hindrance is offered to this movement.
The igniting strip consists of an easily ignitable but slowly burning strip of
paper or woven fabric suitably prepared and provided with primers or caps at
suitable distances such caps being ignited by friction, thus igniting the strip, which
is consumed up to the point on which the strip is held by the pawl or friction
link n.
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 miner's safety lamps a protecting shield or shields provided with deflecting
wings or tongues and suitable apertures substantially as and for the purpose
described.
2. In miner's safety lamps a protecting shield or shields of corrugated or bent
sheet metal provided with deflecting wings or tongues and suitable apertures
substantially as and for the purpose described.
3. In miner's safety lamps a protecting shield and inner ring for controlling the
passage of air to the burner substantially as described.
4. In miner's safety lamps an igniting device consisting of a strip provided with
caps or the like and means for igniting same substantially as described.
5. In miner's safety lamps the igniting device consisting of a box containing the
igniting strip, a casing, ratchet teeth for holding the strip, a pawl and an operating
handle substantially as described.
6. The improvements in miner's safety lamps constructed substantially as
described and illustrated.
PHILIP M. JUSTICE,
Associate Agent.