MENTS IN ELECTRIC LAMPS
Year: 1879

page_text: PROVISIONAL SPECIFICATION left by Joseph Cougnet at the Office of the
Commissioners of Patents on the 20th May 1879.
JOSEPH COUGNET, of Brussels, in the Kingdom of Belgium, Engineer.
MENTS IN ELECTRIC LAMPS."
al
"IMPROVE-
My Invention relates to the construction and arrangement of electric lamps and
consists in the improvements hereinafter described by which a steady electric, light
may be produced and maintained automatically. To a suitable frame or stand I
connect a metal tube in which a piece or crayon of carbon forming the positive pole
of the lamp is placed so as to be capable of moving therein. The upper end of the
said tube is by preference made of platinum and of conical shape so as to close upon
and guide the carbon crayon in its motion. Into the lower end of the said tube.
which is open, is introduced a metal rod or holder upon which the lower end of the..
carbon is held, the said rod or holder is provided at its lower end with a stud or
projection passing through a longitudinal slot in the side of the tube, in which slot
it is capable of motion. To the end of the said stud or projection is attached one
end of a cord or chain or similar connection which passing over a pulley or roller
aflixed to a stop wheel or disc, the axis of which is mounted in brackets at the side
of the tube, has suspended to its other end a weight or counterpoise by which the
said rod or holder and the carbon crayon resting upon it may be made to move up
the said tube. Upon the side of the said tube is mounted an electro-magnet through
which the electric current for producing the light is caused to pass, a wire con-
ducting the said current to the positive carbon terminal. Above the said electro-
magnet and stop wheel or disc is mounted a lever or armature of soft iron, one end
of which is jointed to suitable brackets from which it projects over the stop wheel
or disc to above the electric-magnet; a suitable spring is used to press it upwards
when not influenced by the electric current, and when the electric current passes in
full force through the electro-magnet the said lever or armature is attracted and
drawn down upon the said electric magnet and at the same time presses upon the
said stop wheel, thus preventing its pulley or roller from turning and the carbon
from being moved upwards by the action of the weight, but when the electric
current ceases to pass through the positive carbon, the attraction of the electro-
magnet diminishes and the pressure of the spring raises the lever or armature and
sets free the stop wheel and allows the weight to raise the carbon. The periphery
of the said stop wheel or disc may be roughened or have teeth formed upon it to
engage with a roughened surface or teeth formed underneath the lever or armature
for the purpose of rendering the action of the said lever or armature upon the said
TD 077

page_text: stop wheel or disc more efficacious. In some cases the lever or armature may be
placed underneath the stop wheel or disc and electro-magnet. The negative pole
which is placed above the positive pole or lower carbon consists of a hemispherical
or other shaped metal block or plate, in the underside of which is inserted a piece of
carbon so adjusted by set screws or otherwise as to be just above the positive pole
or carbon of the lamp.
The said block or plate may be of polished metal and may be formed so as to
project the light in any required direction.
The action of the lamp is as follows:-The two poles or carbons being nearly in
contact one with the other, a suitable electric current is caused to pass through the
electro magnet and to the positive pole. from which it passes to the negative pole.
producing a brilliant light through the combustion of the carbon forming the positive
pole as long as the said carbon is in a condition to produce the electric light, the
lever or armature is attracted to the electro-magnet, and resists the action of the
weight tending to raise the said carbon, but as soon as a sufficient portion of the
said carbon is consumed, the electric current passes with less intensity and the lever
or armature is set nearly free and allows of the positive carbon being raised to the
required extent, when the lever or armature is again attracted to the electro-magnet,
and causes the feed of the carbon to cease. When my improved lamp is to be used
in mines where fire damp might occur. I enclose.the space in which the combustion of
the carbon takes place, that is to say, the upper part of the tube carrying the positive
carbon, and the block or plate carrying the negative carbon in a glass globe or
suitably shaped chimney attached at its lower end to the said tube, and at its upper
end connected to a wire gauze tube, extending upwards and covered over with a
metal plate or other suitable covering. The upper part of the said block or plate
forms a circular edge a little above which is an adjustable copper tube concentric
with the said edge and extending upwards to the covering of the lamp. The dis-
tance between the lower edge of the said copper tube and the upper circular edge of
the block or plate may be adjusted by any suitable means, so as to place them
nearer to or further from each other as required. The tube holding the positive
carbon is fixed in another tube closed at the bottom, and containing a quantity of
quicksilver or mercury, which mercury acts to raise the carbon holder and at the
same time the positive carbon, as its terminal is consumed.
The electric current is conducted to the bottom of the lamp tube by a suitable
wire, and passes from the lamp by a second wire at the top of the lamp, a third wire
connected to the first extends outside the lamp to the top of the lamp, when it is
connected with the cover.
The action of the lamp is as follows:-
The electric current entering at the bottom of the lamp ascends through the
positive carbon and passes to the negative carbon, producing a brilliant light.
Should fire damp enter the lamp through the wire gauze tube above described, an
explosion would take place between the said wire gauze tube and the copper tube
within it.
The explosion would raise the temperature, so as to cause the copper tube to
expand and come in contact with the upper edge of the block or plate below it, the
electric current then instead of passing through the positive carbon would ascend
through the outside wire herein before described, and ring a bell or other alarum.
And the deviation of the current thus affected would extinguish the light, thus
preventing accidents from the presence of fire damp.