Improvements in Electric Incandescent Lamps.
Year: 1899

page_text: Date of Application, 27th July, 1899
Complete Specification Left, 26th Apr., 1900-Accepted, 2nd June, 1900
PROVISIONAL SPECIFICATION.
Improvements in Electric Incandescent Lamps.
We, MAX VON RECKLINGHAUSEN, Electrical Engineer, ADOLF VOGT, Electrical
Engineer, NERNST ELECTRIC LIGHT LIMITED, a Public Company, all of 82,
Victoria Street, London, S.W., do hereby declare the nature of this invention
to be as follows:-
Our invention relates to lamps with electrolytic conductors. For use with
such lamps it is desirable to arrange series steadying resistances. To cause the
least waste these series resistances should increase as the current increases, in
fact the more sensitive the series resistance the better. To secure the greatest
sensitiveness it should be at a certain high temperature and it should be at the
same temperature in all parts. The most convenient form is a spiral of wire;
but the ends of the spiral will tend to be cooler than the middle. According to
our invention the spiral is so wound as to obviate this. The wire is wound on
a porcelain or other incombustible support so that the turns come closer at the
ends, being adjusted so that the wire is all at sensibly the same temperature.
We may wind the wires closer at the ends to secure the same result.
The resistances are also needed for preliminary heating. They may be wound
in the same way; but it is then specially important that the supports have as
little capacity for heat as possible, so that the heater heats quickly. The heater
should be also durable; it should heat the rod promptly; it should work in any
position of the lamp; and it should cast as little shade as possible. We secure
these properties as follows:-
We arrange a platinum or other refractory wire so that it is wound in loose
spirals, so that it is never in a state of stress. These loose spirals are threaded
on a thin rod of porcelain or other incombustible material. The rod is bent
into a zigzag or snake form, and it is suspended so that it is always just under
the filament which is to be heated; that is to say, it is pivotted on the axis of
the filament, so as to swing freely. Another form of heater consists of fine
wire wound on a thin walled porcelain tube of elliptical section. This is hung
edgeways so as to give the least shadow possible, while giving a large convec-
tion current of hot air to the light giving filament.
Dated this 27th day of July 1899.

page_text: Improvements in Electric Incandescent Lamps.
We, Max VON RECKLINGHAUSEN, Electrical Engineer, ADOLF VOGT, Electrical
Engineer, and the NERNST ELECTRIC LIGHT, LIMITED, a Public Company, all of
82, Victoria Street, London, 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:
6
These improvements relate to electrical incandescent oxide or Nernst" lamps
whose filament or electrical conductor (which is to be rendered incandescent) has
to be first heated before it can serve as a conductor for the current by which it
is subsequently to be kept in a heated incandescent state.
..
For use with such lamps it is desirable to arrange series steadying resistances.
To cause the least waste these series resistances should increase as the current
increases, in fact the more sensitive they are the better. To secure the greatest
sensitiveness they should be at a certain high temperature and should be at the
same temperature in all parts. The most convenient form is a spiral of wire,
but the ends of the spiral will tend to be cooler than the middle. According to
our invention the spiral is so wound as to obviate this. The wire is wound on a
porcelain or other incombustible support in such a way that the turns are brought
closer together at the ends than at the centre.
We also use similar resistances for the preliminary heating of the lamp
conductor.
It is then specially important that the supports have as little capacity for
heat as possible, so that the heater heats quickly. The heater should be also
durable and it should heat the rod promptly.
To effect this we arrange a platinum or other refractory wire so that it is
wound in spirals, so that it is never in a state of stress. These spirals are
threaded on a thin rod of porcelain or other incombustible material. The rod
is bent into a zigzag or snake form, or it might be passed around the conductor
in an open spiral.
In this way not only is large heating surface obtained for heating the con-
ductor, but in addition any shadow caused by one part of the preliminary heat-
ing coil obstructing the passage of light from one part of the conductor is
illuminated by light proceeding from other parts of the conductor and no dis-
tinct shadow is anywhere produced.
If the lamp conductor is in a horizontal plane we suspend the preliminary
heater so that it hangs always just under the filament or lamp conductor, that
is to say, it is pivotted on the axis of the filament or lamp conductor so as to
swing freely and always remain below it.
Or the wire coil of the preliminary heater may be mounted on a flattened
tube or strip of porcelain hung edgeways below the lamp conductor so as to give
the least shadow possible whilst giving large heating surface for causing a
current of heated air to rise up to the conductor.
Figure 1 shows a diagram perspective view of the heater of wire coil con-
struction suspended on pivots as above described and bent into a zigzag form
in a horizontal plane.
Figure 2 is a similar view shewing the zigzag support for the heating coil
bent into a part cylindrical form.
Figure 3 is a similar view shewing the zigzag support for the heating coil
passing around the lamp conductor as an open spiral.
Figure 4 is a plan view of the conductor and heater coil shewn in Figure 1.

page_text: Figures 5 and 6 are side and end views of a similarly suspended heater, in
which the wire coil surrounds a thin flat plate of porcelain or like material
set up edgewise vertically.
Figure 7 side view of one of the lamps the preliminary heater of which is formed
as shewn in Figures 5 and 6.
In these figures Z is a steadying resistance formed as herein before described
placed in series with the filament or lamp conductor to limit the amount of
current which can pass when the filament or lamp conductor becomes heated.
a is the conductor or lamp filament. b c leads passing to conductor. d is the
heater formed of a thin rod of porcelain surrounded by a heating wire coil d
and bent as shewn into an undulating form as in Figures 1 to 4 or of a thin flat
plate or tube held edgewise vertically as in Figures 5 to 7. When the lamp
filament or conductor is horizontal as in Figures 1 and 2 and 4 to 7 the ends of
the wire coil are made to extend upwards for a distance and are then bent to
form pivots ik which-enter loops in the ends of leads e f-these loops are near
the two ends of the conductor a and approximately on a line with it-the pivots
thus serve to convey current from the leads ef to the heating coil and the
heater always hangs below the conductor whether the lamp be held in a vertical
or horizontal position. g is a holder containing cut-out mechanism for arresting
the passage of current to the heater coil so soon as sufficient current passes
through the conductor a. h is a glass globe.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is:-
1. An electrical incandescent oxide or "Nernst " lamp having a resistance
such as herein before described in series with its filament or conductor to control
the amount of current that can pass when the filament becomes heated.
2. An electrical incandescent oxide or "Nernst" lamp whose conductor has
held in proximity to it a preliminary heater bent into an open zigzag or undulat-
ing form so as to give as little shadow as practicable.
3. An electrical incandescent oxide or "Nernst" lamp whose conductor has
hung below it a heating wire coil supported upon a thin flat plate or flattened
tube hung edgewise in a vertical plane so as to give as little shadow as practic-
able.
4. An electrical incandescent oxide or "Nernst" lamp whose conductor has a
preliminary heater suspended below it from pivots approximately in a line with
the conductor so that the heater may always hang below the conductor whether
the lamp be mounted vertically or horizontally.
5. The construction of preliminary heaters for electrical incandescent oxide or
"Nernst" lamps substantially as herein before described.
Dated
MAX VON RECKLINGHAUSEN.
ADOLF VOGT.
NERNST ELECTRIC LIGHT LIMITED.
HENRY C. MANCE,
BRUCE ZUSMAN,
} D
Directors.
G. OPITZ, Secretary.