Improvements in Miners' Safety Lamps to Enable them to Indicate the Presence of Fire-damp.
Year: 1887

page_text: Date of Application, 25th Apr., 1887
Complete Left, 25th Feb., 1888
.Complete Accepted, 29th Mar., 1883
Improvements in Miners' Safety Lamps to Enable them to Indicate
the Presence of Fire-damp.
I, ALEXANDER SCHANSCHIEFF of Gipsy Hill in the County of Surrey, Electrician,
do hereby declare the nature of this invention to be as follows:-
It has been suggested to indicate the presence of fire-damp in mines by comparing
the brightness of two equal platinum wires, one enclosed in a glass globe, the other
in the open air, and both rendered incandescent by the passage of the same electric
current. If there is no fire-damp in the air both wires give an equal light. If
there is a fire-damp the wire exposed to it gives a brighter light than the protected
wire...
. According to my invention I attach to an electric safety lamp a fire-damp detector
made on this principle.
In place however of a platinum wire enclosed in a globe I prefer to use a carbon
filament, and I so arrange the apparatus that by turning a switch the current can be
diverted from the main lamp and passed through the fire-damp detector.
I make openings to admit air (or air and fire-damp as the case may be) between
the outer glass of the lamp and the glasses containing the carbon filament.
In place of the detector as above described, I sometimes employ one which acts
upon the principle of igniting the mixture of fire-damp and air. In the space
between the two glasses I have a platinum wire through which the current from tho
battery can be switched, as above described. If there is any material proportion of
fire-damp in the air, it is ignited by the incandescent platinum wire-and-the-per
centage and consequent danger can be judged by the duration of the combustion.
-I-sometimes so arrange that the openings are closed by the movement of switching
on the detector the only communication with the outer air being then through wire
gauze.
CARPMAEL & Co.,
Agents for the Applicant.

page_text: C
the Presence of Fire-damp.
I, ALEXANDER SCHANSCHIEFF of Gipsy Hill in the County of Surrey, Electrician,
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-
According to my invention I attach to an electric safety lamp a fire-damp detector
and Iso arrange the apparatus that by turning a switch the current can be diverted
from the main lamp and passed through the fire-lamp detector.
1 make openings to admit air (or air and fire-damp as the case may be) between
the outer glass of the lamp and the glass of the glow lamp. In the space between
the two glasses I have a platinum wire through which the current from the battery
can be switched, as above described. I sometimes so arrange that the openings are
closed by the movement of switching on the detector the only communication with
the outer air being then through wire gauze.
When in use the lamp and battery is placed in the first instance, near the roof of
the workings to be tested, with its fire-damp chamber upwards and in a horizontal
position, the valve before mentioned being open.
When a charge has permeated through the chamber the battery and lamp is lowered
(still in its horizontal position) to near the floor of the working, so as to be in the
region of the least amount of the possible explosive mixture, here the switch is turned
on, and immediately the platinum wire glows, the amount of luminosity depending
upon the percentage of explosive gas within the testing chamber.
Should the amount of fire-damp be so large as to cause the platinum wire to become
white hot and thereby cause a small internal explosion, the flame cannot be communi-
cated to the surrounding atmosphere owing
:-
1st. To the protection afforded by the wire gauze.
2nd. To the fact that the actual test is made near the ground and therefore away from
the dangerous mixture.
By the use of an india-rubber and flexible reservoir or other means a supply of the
air to be tested may be brought from the workings to the pit's mouth and by
discharging its contents into the testing chamber it may there be tested, thus avoiding
all possibility of explosion.
DESCRIPTION OF THE DRAWINGS.

page_text: a is the casing of the battery, bis the glow lamp whose stem enters the split socket c
one half of the socket being connected to one wire d of the battery and the other
half to the wire e and thence through the switch to the other wire e of the battery.
These wires are embedded in the sides of the battery as is described in the Specification
of my former patent No. 213487.
The switch consists of the two springs ƒ and g and the lever h pivoted at h¹ which
pivot is connected to the battery wire e. The spring 7 is connected to one end of
the platinum wirok whose other end is connected to the battery wire d. The tail end
of the lever h enters a slot in the ring 1 which is provided with handles by which
it can be turned so that the lever h can be made to complete the circuit either through
the spring and the lamp or through the spring g and the platinum wire k. The
end of tho lever is so formed that as it is switched over it comes into contact with
one spring before it leaves the other so that the current is never broken and sparking
is prevented.
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 1
claim is :-
1. The combination of a battery, a lamp, a fire-damp detector and a switch tho
whole being so arranged that the current can be switched at pleasure either through
the lamp or the detector substantially as described.
2. My improvements in miners safety lamps to enable them to indicate the
presence of fire-damp substantially as described.
1000