Improvements in Electric Incandescence Lamps and Apparatus or Appliances in connection therewith.
Year: 1897

page_text: Date of Application, 12th Oct., 1897
Complete Specification Left, 11th July, 1898-Accepted, 13th Aug., 1898
PROVISIONAL SITULLICATION.
Improvements in Electric Incandescence Lamps and Apparatus or
Appliances in connection therewith.
I, Dr. WALTHER NERNST, Professor, of 50, Burgerstrasse, Gottingen, Germany,
do hereby declare the nature of this invention to be as follows:-
My invention refers to that class of electric incandescence lamps, the incan-
descence body of which is not made of a material being a conductor of electricity
at the ordinary temperature, but only becoming a conductor when it is heated
to a high temperature, such as magnesia, zirconia. lime and other oxides of metals.
The invention consists in the arrangement of lamps having such incandescence
bodies in combination with appliances or apparatus for establishing in the said
bodies the high temperature necessary for transforming them into a conductor of
electricity.
Such lamps and appliances are mainly constructed as follows:
Surrounding, or in proximity to the said incandescence body is arranged a coil
or equivalent form of a refractory electrical conductor having a high resistance,
such as a coil of platinum wire, that will become highly heated by the passage
of an electrical current through it. the coil being arranged in combination with
an envelope of a refractory material that is a bad conductor of heat such as glass,
porcelain, fire clay, and the like. This coil and envelope may either be arranged
so as to permanently surround the incandescence body, in which case the refractory
envelope is made of glass so as to allow of the passage through it of the light
emitted by the incandescence body; or the coil and envelope may be made of a
dome-shape arranged above the incandescence body, which is situated in the focus
of the spherical dome, so that when the coil is heated by the passage of a current,
the heat is reflected in a concentrated manner on to the said body so as to raise it to
the requisite degree of heat, without interfering with the emission of light there-
from or again, when the incandescence body is surrounded by the coil as first
described, the parts may be so arranged that when the body has become sufficiently
heated to act as an electrical conductor, either the coil and envelope are auto-
matically removed from the incandescence body, or the latter is automatically
removed from the former, so that the envelope shall not impede the transmission
of the light.
In all of the above described arrangements, either the incandescence body is
contained in one electrical circuit supplied with electrical energy, and the heating
coil is contained in another circuit connected with a separate subsidiary source of
electrical energy, or the heating coil is included in a shunt of the circuit of the
incandescence body. In the first arrangement, on the circuit of the subsidiary
supply being closed, the current will heat the coil which in its turn will heat the
incandescence body, so that this, in thus becoming a conductor, will allow of the
passage of the current from the main supply through it, and will thereby be heated
to incandescence.
When this is effected, the subsidiary supply is cut off from the heating coil,

page_text: either by hand, or automatically by a contact breaker actuated by the main current
in any suitable manner.
In the second described arrangement, when the circuit of the source of electrical
energy is closed. the whole of the curront will at first pass through the shunt
circuit to the heating coil, as the incandescence body will then act as a non-con-
ductor, preventing the passage of the current through the main circuit.
When the body has become heated by the coil so as to act as a conductor, the
current will then either be automatically transferred to the main circuit, if the
resistance of the heated incandescence body be arranged to be sufficiently smaller than
that of the heating coil, or the shunt circuit may be broken for this purpose.
either by hand, or automatically by the action of the current in the main circuit
upon a suitable contact breaker.
In the before described arrangement wherein the incandescence body is auto-
matically removed from the heating coil and its envelope when the former has been
sufficiently heated, this may be effected by means of the following arrangement.
The incandescence body is suspended by a conductor from an iron core, which
in its turn, is suspended from a spring so as to be partly situated within a solenoid
included in the circuit of the incandescence body.
Before the latter is heated, no current will be passed through the solenoid and
the spring will then hold the incandescence body in n raised position in which it
will be situated within the heating coil. As soon as the body has become suf-
ficiently heated, the current, in passing through the circuit, will cause the solenoid
to attract and draw downwards the core, in opposition to the spring, and the
incandescence body will consequently also descend so as to be free of the heating
coil. The conductors leading to and from the incandescence body are connected by
suitable flexible conducting connections to the electric circuit in order to allow of
the above described motion of the body.
ABEL & IMRAY,
Agents for the Applicant.
Improvements in Electric Incandescence Lamps and Apparatus or
Appliances in connection therewith.
I, Dr. WALTHER NEUNST, Professor, of 50, Burgerstrasse, Gottingen, Germany,
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:-
1
My invention relates to that class of incandescent lamps the incandescence body
of which is not made of a material being a conductor of electricity at the ordinary
temperature, but only becoming a conductor when it is heated to a high temper-
ature, such as magnesia, zirconia, lime and other oxides of metals.
The invention comprises apparatus for establishing in the incandescence body
of such lamps the high temperature necessary for transforming it into a conductor
of electricity, as I shall describe referring to the accompanying drawings.
Fig. is a diagrammatic view partly in section of a lamp according to my
invention.
Tig. 2 is a similar view shewing a modification.
Fig. 3 is a diagrammatic view of another modification.
Similar letters of reference designate like parts in all the figures.

page_text: G is the incandescent body, K³ K and K¹ K² (Fig. 3) are binding posts connected
with the terminals of some source of electricity such as E¹ (Fig. 3) and conducting
the current to the incandescent body G. The circuit of G is marked I.
P is a coiled or helical wire made of some refractory electrical conductor such as
platina. M is a sleeve or mantle of refractory nonconducting material such as
porcelain.
The wire P is inserted in a second circuit II fed by a separate source of
electricity E2 (Fig. 3) or it might be derived in shunt from the main circuit I.
S (Fig. 3) is a solenoid coil surrounding the lower end of an iron core n which is
suspended by a spring F from a fixed point I whilst G is suspended from 7.
K and K³ are electrically connected by flexible conductors such as copper ribands
or the like to K³ and K.
The operation of the lamp is as follows.
Both circuits I and II being closed, in circuit I there is no current at first,
because the body G in this circuit acts as a non conductor until heated to a high
temperature. In circuit II however there is a current which heats the wire P.
The latter imparts its heat by radiation and convection to G partly directly and
partly to the mantle M and thence indirectly to G. As soon as G thus becomes
sufficiently heated it also becomes a conductor and consequently a current is set up
in I which henceforth keeps G glowing.
Circuit II can now be interrupted either by hand or by any known automatic
means.
In the construction shewn in Fig. 1 it is assumed that the sleeve M is made of
some transparent material such for instance as glass. In that case, although the
body G remains covered by the sleeve M it is not prevented from emitting light.
If the heating body consists merely of a helical wire placed sufficiently near the
incandescent body, the mantle may be omitted.
In the modification shown in Fig. 2 the mantle M is constructed as a concave
mirror, so that it will concentrate the heat rays on the body G placed in its
focus.
The device shown in Fig. 3 acts in the following manner. As soon as the
temperature of G is sufficiently raised to make it conduct the current generated
in E, that current passes through K, L, K³, G. K¹, L¹, K³, S and back
to E¹
The coil S therefore becomes excited and draws in the iron core n thereby at the
same time lowering the incandescent body G down from the interior of the heating
device P M.
Obviously the device shown in Fig. 3 could be so arranged that the incandescent
body remains fixed while the heating device PM is withdrawn from it auto-
matically when the current in circuit I is set up.
Also the current in the circuit I might be utilised for applying a suitable cut
out to interrupt the circuit II automatically when the lamp is started.
Having now particularly described and ascertained the nature of this
invention and in what manner the same is to be performed. I declare that what
I claim is:
1. In electrical incandescent lamps the combination of an electrical heating
device with an incandescent body consisting of a material, that is a non-conductor
when cold and a conductor when heated to a high temperature, substantially as
and for the purpose set forth.
2. In electrical incandescent lamps the combination with an incandescent body
consisting of a material that is a non-conductor when cold and a conductor when
heated to a high temperature of a suitable resistance combined, with
a sleeve or mantle of heat proof non-conductive material the whole
being placed in the vicinity of or surrounding the said incandescent body and

page_text: described.
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.3. In electrical incandescent lamps the combination with an incandescent body
made of a material, that is a non-conductor when cold and becomes a conductor
when heated to a high temperature of a resistance combined with a sleeve of fire proof
non-conducting and transparent material such as glass surrounding the said inean-
descent body and means for electrically heating said resistance substantially as
and for the purpose described.
4. In electrical incandescent lamps the combination with an incandescent body
made of a material, that is a non-conductor when cold and becomes a conductor
when heated to a high temperature of a resistance and a heat confining mantle
preferably of heat-proof material, said mantle being shaped like a concave mirror
and being placed in the vicinity of said incandescent body in such a position that
the latter is practically in its focus substantially as and for the purpose described.
5. In electrical incandescent lamps the combination with an incandescent body
made of a material, that is a non-conductor when cold and becomes a conductor when
heated to a high temperature of a resistance combined with a heat confining sleeve
surrounding the said incandescent body and means to withdraw the latter from
within said sleeve automatically as soon as a current is set up in it substantially as
and for the purpose described.
G. In electrical incandescent lamps the combination with an incandescent body
made of a material, that is a non-conductor when cold and becomes a conductor
when heated to a high temperature of a coil connected in series with said
incandescent body an iron core fastened to the same being suspended from a
spring F and dipping into said coils of a resistance combined with a heat confining
sleeve arranged to partially surround said incandescent body when the coils is not
excited substantially as and for the purpose described.