Improvements in Incandescent Arc Electric Lamps.
Year: 1898

page_text: Date of Application, 22nd Dec., 1893 -Accepted, 2nd June, 1899
Improvements in Incandescent Arc Electric Lamps.
I WILLIAM EDWIN IRISHI, of 502, New England Building, Cleveland, County
of Cuyahoga, State of Ohio, United States of America, Electrician, do hereby
declare the nature of this invention and in what manner the same is to bo
performed to be particularly described and ascertained in and by the following
statement:
My invention relates to improvements in incandescent are electric lamps, and
the object of the invention is to obtain from the arc formed between electrodes of
high conductivity the requisite heat to produce conductivity in a medium which
offers a very high resistance when cold, but becomes conductive when heated to
incandescence, this medium being introduced into the circuit and finally forming
a part thereof.
I exemplify my invention in several ways, as hereinafter described, shown in
the accompanying drawings and introduced in the claims.
In the accompanying drawings Fig. 1 shows a sectional view of two carbon
electrodes, and the incandescing medium is shown as a core passing loosely through
each carbon and meeting at the central point between them; Fig. 2 shows a
similar view of electrodes with one strip of the incandescing medium placed as
a core in one of them; Fig. 3 shows the medium sheathed over the carbons; and
Figures 4, 5, 6 and show forms into which the incandescing medium can be
moulded
In these figures 1, 1, are the conducting electrodes; 2 is a medium of less
conductivity than the carbons and highly refractory, conducting and incandezcing
under heat.
As shown in Fig. 1, the electrodes of carbon or other highly conducting material
are hollow and a core or filling of a material or composition of much less con-
ductivity than the carbons, but becoming conductive when heated to incandescence
is inserted therein, the cores touching one another at all times.
These cores under the heating effects of the arc to which they are directly
exposed will become incandescent without much loss of material from disintegra-
tion or consumption.
As soon as incandescent the cores will become conduct've and the entire current
will pass through them, thus immediately cutting out the arc, which will be
extinguished.
The current will flow through the core thereafter, maintaining its heat and
conductivity meanwhile until cut off from the lamp, since its resistance to the
current will cause it to become incandescent.
I believe myself to be the first to substitute in a lamp an incandescent medium
for the arc, the arc itself contributing to heat the medium to conductivity and
thereby extinguishing itself while the current flows through the medium.
It is well known that many of the oxides of rare metals, such as zirconium,
thorium, magnesium, calcium, are highly refractory under heat, and when cold
offer a high resistance to the electric current, but when heated become good
conductors of electricity.

page_text: I therefore employ highly refractory oxides of these characteristics for my incan-
descing medium, which when cold offer resistance to the current, but when heated
by the closely adjacent are become sufficiently conductive to maintain the circuit,
to the exclusion of the arc, and are maintained by the current in a state of in-
candescence, the light obtained thereby being greater than obtainable from the
carbon on account of the greater heat possible without volatilizing the medium.
I also produce in this manner an automatically lighting lamp.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is:-
1. In an arc lamp, means for substituting an incandescent medium for the are
consisting of, the combination with the carbons of a connecting core between the
carbons, the said core being composed of substances normally partially non-
conductive of the electric current but adapted to become conductive under the
influence of heat, substantially as and in the manner described.
2. In an arc lamp, means for substituting an incandescent medium for the arc,
consisting of the combination with the carbons; of a core of incandescing and
refractory material connecting the carbons, the said core being composed of
normally partially non-conductive material but which becomes conductive under
the influence of the arc, and thereupon conveys the current and maintains the
lamp circuit to the exclusion of the are, substantially as and in the manner
described.
3. The heretofore described method of substituting an incandescent medium
for an are in an are lamp, consisting in: first turning the circuit through the
arc; heating by means of the are an incandescing medium connecting the carbons,
and thus making the medium conductive, when previously partially non-con-
ductive, and finally maintaining the circuit through the medium to the exclusion
of the arc, and maintaining the incandescence of the medium thereby, substantially
as described.
Dated THIS LIT
n presence of
WM. M. MONROE.
C. H. OLDS.
01 January 1000.
WILLIAM E. IRISH.