Improvements in and relating to Incandescent Electric Lamps.
Year: 1891

page_text: Date of Application, 7th Nov., 1891
Complete Specification Left, 20th July, 1892—Accepted, 20th Aug., 1892
PROVISIONAL SPECIFICATION.
[Communicated from abroad by LA SOCIÉTÉ DITE ELECTRICITEITS MAAT-
SCHAPPIJ, SYSTEM DE KHOTINSKY (President, Ludwig Wilhelm Schoffer),
of Gelnhausen, in the Empire of Germany.]
Improvements in and relating to Incandescent Electric Lamps.
1, HENRY HARRIS LAKE of the firm of Haseltine Lake & Co. Patent Agents,
45 Southampton Buildings, in the County of Middlesex do hereby declare the
nature of this invention to be as follows:-
In incandescent electric lamps operating at higher tensions than 130 volts and in
those lamps in which the number of watts expended in the lamp per standard
candle is very small, that is to say in lamps expending 2 watts or less per standard
candle, a peculiar phenomenon is exhibited which English electricians designate by
the name of "flaming."
This flaming consists in the appearance of a small blue flame at one of the points
of junction of the platinum wire with the carbon filament; the flame is similar to
that produced in a Geissler tube. The lamps in which this blue flame is produced
have not a long life. A spark is easily produced between the two junction points
and this spark causes the fusion of the platinum wire and practically renders the
lamp useless for the vaporized carbon and platinum completely blacken the lamp
glass.
The object of my invention is to prevent the occurrence of the aforesaid
phenomenon and to obviate the inconveniences resulting therefrom.
The device which I use for this purpose comprises a plate of any suitable material
arranged between the connecting points or junctions of the platiuum wire and the
carbon filament. This plate, preferably made of glass, has the form of a circular
disc and is fixed to a small stalk secured to the bulb of the lamp in such a manner
that the junction of the platinum wires with the filament are at the same level as
the centre of the plate or disc.
In the accompanying drawing
Figures 1 and 2 represent one form of my arrangement by way of example.
a, a are the two platinum wires, 6 the carbon filament, c, c the connecting points
or junctions of the platinum wire with the filament; d is the separating plate or
disc placed between the two leading-in wires a, and supported by a small stalk e.
Experiments made with incandescent electric lamps operating at higher tensions
than 130 volts and with incandescent electric lamps which have a higher efficiency
than 2 watts per candle have shown that the device above described has the effect
of suppressing the flaming in most cases. In case flaming is produced its injurious
effects are nullified. It is only in cases when a lamp is run with a voltage very
much higher than its normal voltage that any failure need be feared.
Dated this 7th day of November 1891.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in and relating to Incandescent Electric Lamps.
n I HENRY HARRIS LAKE of the firm of Haseltine Lake & Co. Patent Agents
45 Southampton Buildings in the County of Middlesex 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 :-
In incandescent electric lamps operating at higher tensions than 130 volts and in

page_text: those lamps in which the number of watts expended in the lamp per standard
candle is very small that is to say, in lamps expending 2 watts or less per standard
candle a peculiar phenomenon is exhibited which English electricians designate by
the name of "flaming."
This flaming consists in the appearance of a small blue flame at one of the points
of junction of the platinum wires with the carbon filament the flame is similar to
that produced in a Geissler tube. The lamps in which this blue flame is produced
have not a long life. A spark is easily produced between the two points and this
spark causes the fusion of the platinum wire and practically renders the lamp
useless as the vaporized carbon and platinum completely blacken the lamp glass.
The object of my invention is to prevent the occurrence of the aforesaid
phenomenon and to obviate the inconveniences resulting therefrom.
The device which I use for this purpose comprises a plate of any suitable material
arranged between the connecting points or junctions of the platinum wire and the
carbon filament. This plate, preferably made of glass, has the form of a disc and
is fixed to a small stem secured to the bulb of the lamp in such a manner that the
points of connection of the platinum wires with the filament are at the same level as
the centre of the plate or disc.
In the drawing left with my Provisional Specification I have shown how my
invention may be conveniently and advantageously carried into practice.
Figures 1 and 2 represent by way of example two separate views of my improved
lamp.
a a are the two platinum wires, 5 the carbon filament, c c the connecting points
or junctions of the platinum wires with the filament, is the separating plate or
disc placed between the two leading-in wires a and supported by a small stem e.
'
Experiments made with incandescent electric lamps operating at higher tensions
than 130 volts and with incandescent electric lamps which have a higher efficiency
than 2 watts per candle have shown that the device above described has the effect
of suppressing the flaming in most cases. In case flaming is produced its injurious
effects are nullified. It is only in cases when a lamp is run with a voltage very
much higher than its normal voltage that any failure need be feared.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed as communicated to me by
my foreign correspondents I declare that what I claim is
The employment of a disc or plate in the interior of the bulbs of incandescent
electric lamps and between the connecting points of the conductors and carbon
filament in principal substantially as and for the purpose above specified.
Dated this 20th day of July 1892.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicant.