Improvements in and relating to Electric Incandescence Lamps.
Year: 1899

page_text: Date of Application, 1st Sept., 1899-Accepted, 25th Nov., 1899
[Communicated from abroad by ALLGEMEINE ELEKTRICITÄTS GESELLSCHAFT, of
22, Schiffbauerdamm, Berlin, Germany.]
Improvements in and relating to Electric Incandescence Lamps.
I, VICTOR ISIDORE FEENY, of 60, Queen Victoria Street, in the City and County
of London, Chartered Patent Agent, 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 electric incandescence lamps of the
"Nernst" type, and in particular to the incandescence bodies or incandescence
elements consisting of second-class conductors, which are, in the present invention,
inserted parallel to one another.
As comprehensive experiments have shewn, every incandescence rod for incan-
descent electric lights composed of one or more second-class conductors, has a
sphere of action which is dependent upon the material and.considerably limited
thereby. If, now, several cylindrical or tube-shaped incandescence rods be inserted
parallel to one another and the system be excited, the following alternative pos-
sibilities will occur. In the one case, the incandescence rods can only be arranged
at such slight distances apart, that the thermic spheres of action overlap one
another to a certain extent. In this particular arrangement of the rods, it is
usually sufficient to bring one only into a state of incandescence in order, by
mutual heating or conductivity, to bring the whole parallel inserted series into
such condition, and to keep it so.
In the other case, the incandescence rods can be arranged at such a distance
from each other that the reciprocal spheres of thermic action cannot impinge upon
one another. In this case, it is possible, under special circumstances, to effect
the excitation of, and the lighting by, a single incandescence rod, and when
this is burned away, to have another of the parallel rods inserted in its place at
once.
On the accompanying drawing, several forms of the arrangement of such incan-
descence bodies are illustrated.
Figures 1 and 2 represent the incandescent rods arranged close together,
respectively in a circle and as a diamond.
Figure 3 illustrates in like manner a plane or compound flat-shape incandescence
body formed of small tubes.
Figure 4 shows an incandescence body with rods or tubes far apart from one
another, which arrangement is provided with a common or mutual resistance
or rheostat.
In the incandescence bodies shown in Figures 1 to 3, the thermic spheres of
action of the separate rods overlap one another. The more or less easy starting
of the whole of the rods depends essentially upon the nature of the material
employed in the manufacture of the rods. Preferably such mixtures of second-
class conductors (electrolytes) should be employed, as conduct the current even
at low temperatures.
The arrangement illustrated in Figure 4 shows an incandescence body, which
consists of two or more rods G1, G2, G3, inserted parallel to one another. These
are arranged inside the glass globe K and the heating coils H, H', serving for the

page_text: excitation at such a distance from one another that their thermic spheres of action
do not impinge the one on the other. After one rod has been excited by the
heating coils, the heating current is interrupted and as a matter of fact, generally,
the uppermost rod is first started, because it is the most quickly heated. If this
rod be worn out, or damaged by mechanical action, another of the parallel inserted
rods starts at once to act for the same. By this arrangement, consequently, the
successive burning away of the several incandescence bodies is obtained, and the
duration or life of a lamp containing five rods inserted parallel, with a life of
four hundred hours for a single rod, as is easily attained by electrolytic incan-
descent rods with an initial requirement of 15 Watt per candle power, reaches
or is extended to two thousand hours.
The method of insertion described can be employed with all incandescence bodies
which insulate well at low temperatures, independently of the special nature of the
heating apparatus, because only with such incandescence rods is it possible, with-
out noticeable loss of current, to leave a larger number of parallel inserted rods
under tension, whilst only a single rod is in a state of incandescence.
If an electrolytic material be employed in which the resistance, with increasing
strength of current declines more rapidly in proportion than the strength of
current, care is taken that, with increasing strength of current, the tension at the
ends of the incandescence body diminishes. A rod made of such material can thus
only actually burn if furnished with a resistance (rheostat). If a series of such incan-
descence rods be inserted, which, for example, with normal burning require 96 volts
and a 0'4 ampère, with their electrodes parallel to each other and be supplied, with
a resistance (rheostat) of 35 ohms. to a 110 volt conductor, only one rod can burn
continuously, for with more than one incandescence body burning, a larger
amount than 14 volts would be absorbed by the resistance. The tension would
thus be too slight, especially if the resistance were made of a material, iron wire
for instance, which with greater strength of current becomes very strongly heated
and at the same time conducts rather badly. In fact experience also shows that
under the conditions described, it is easy to excite several incandescence rods with
one flame, but that it is quite impossible after removal of the heating flame to
keep more than one incandescence rod continuously burning. Even if directly
after the excitation more than one rod is traversed by the current, the condition
will be such that the slightest variation will be sufficient to extinguish all but
one of the incandescence bodies in a very few seconds.
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 electrical lamps, an incandescence body for electric incandescent light com-
posed of second-class conductors, characterized by the insertion of incandescence
rods or tubes or similar incandescence elements which have the property of con-
ducting badly at an ordinary temperature and doing so well in a state of incan-
descence, by the arrangement of a common or mutual resistance for the parallel
inserted incandescent elements, and by the fact that the thermic spheres of action
cannot engage or interfere with one another or come into contact together,―for
the purpose of enabling incandescent bodies for high illuminating power or burn-
ing for long periods to be produced as desired, substantially as described.
Dated thio First dow of Swtember 1899
mber 1899
For the Applicant,
GEDGE & FEENY,
Chartered Patent Agents,
60, Queen Victoria Street, London, E.C.
Dated this First day of September 1899
For the Applicant,
GEDGE & FEENY,
Chartered Patent Agents,
60, Queen Victoria Street, London, E.C.