Improvements in Incandescence Bodies for Electric Glow Lamps.
Year: 1890

page_text: [Communicated from abroad by the firm of SIEMENS AND HALSKE, of 94, Mark-
grafenstrasse, Berlin, in the Empire of Germany, Electrical Engineers.]
Improvements in Incandescence Bodies for Electric Glow Lamps.
We, SIEMENS BROS. & Co. LIMITED, of No. 12, Queen Annes Gate, Westminster,
in the County of Middlesex, do hereby declare the nature of this invention to be as
follows:-
This invention relates to improvements in the production of incandescence bodies
for electric glow lamps whereby a core consisting of an incandescence body such as
a carbon filament or rod is covered with a coating of a refractory material con-
sisting of refractory metallic carbides, nitrides, phosphides and sulphides, as also
combinations of the refractory metalloids silicon and boron with refractory metals,"
or with various compounds of the said bodies.
By the employment of such coatings the incandescence bodies are protected
against electric disintegration and against damage by transport, and as the resistance
to the electric current of such coatings is greater than that of the graphite coatings
heretofore employed, the coating can be made of greater thickness than the latter,
and thicker carbon cores can also be used, whereby the durability of the lamps is
greatly increased.
With regard to the technical production of the carbides, nitrides, phosphides and
sulphides, there may be advantageously employed, in addition to the processes
used in chemistry, the following process in which electricity is mainly employed as
the separating agent.
When using the carbides the metal is preferably deposited together with carbon
from volatile metallic compounds in the presence of a hydrocarbon and hydrogen,
or the carbon filaments saturated with easily reducible compounds poor in oxygen,
are heated to incandescence in an atmosphere of hydrocarbon, so as to enrich the
separated metals with carbon.
For the preparation of the nitrides, the carbon filaments saturated with haloid-
ammonia-double-salts of the metals, are heated to incandescence in an atmosphere
of ammonia, or the filaments, already provided with a metal coating, are heated to
incandescence in an atmosphere of nitrogen.
The sulphides and phosphides are obtained by gradually heating to incandescence
the carbon filaments, coated with metal, in an atmosphere of sulphur or phosphorus
vapour in the usual preparing apparatus, or in many cases the carbon filament,
saturated with chlorides or oxides compounds, are heated to incandescence in
sulphuretted hydrogen, sulphide of carbon, mercaptan, or phosphoretted hydrogen,
and phosphites.
For the preparation of the various metallic compounds numerous combinations
can be employed.
By suitable regulation of the temperatures of separation in the preparing
apparatus, and appropriate dilution of the mixtures of volatile compounds of carbon,
nitrogen, phosphorus, and sulphur to be used, coatings of varying electric conducting
powers can be obtained.
Dated this 10th day of July 1890.
3
Agents for the Applicants.

page_text: Improvements in Incandescence Bodies for Electric Glow Lamps.
We, SIEMENS BROS. & CO. LIMITED, of No. 12, Queen Annes Gate, Westminster,
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 ascer-
tained in and by the following statement :-
This invention relates to improvements in the production of incandescence bodies
for electric glow lamps whereby a core consisting of an incandescence body such as a
carbon filament or rod is covered with a coating of a refractory material consisting
of refractory metallic carbides, nitrides, phosphides and sulphides, as also combina-
tions of the refractory metalloids silicon and boron with refractory metals, or with
various compounds of the said bodies.
By the employment of such coatings the incandescence bodies are protected
against electric disintegration and against damage by transport, and as the resistance
to the electric current of such coatings is greater than that of the graphite coatings
heretofore employed, the coating can be made of greater thickness than the latter,
and thicker carbon cores can also be used, whereby the durability of the lamps is
greatly increased.
With regard to the technical production of the carbides, nitrides, phosphides and
sulphides there may be advantageously employed, in addition to the processes used
in chemistry, the following process in which electricity is mainly employed as the
separating agent.
When using the carbides the metal is preferably deposited together with carbon-
from volatile metallic compounds in the presence of a hydrocarbon and hydrogen,
or the carbon filaments saturated with easily reducible compounds poor in oxygen,
are heated to incandescence in an atmosphere of hydrocarbon, so as to enrich the
separated metals with carbon.
For the preparation of the nitrides, the carbon filaments saturated with haloid-
ammonia double salts of the metals, are heated to incandescence in an atmosphere
of ammonia, or the filaments, already provided with a metal coating, are heated to
incandescence in an atmosphere of nitrogen.
The sulphides and phosphides are obtained by gradually heating to incandescence
the carbon filaments, coated with metal, in an atmosphere of sulphur or phosphorus
vapour in the usual preparing apparatus, or in many cases the carbon filament,
saturated with chlorides or oxygen compounds, are heated to incandescence in
sulphuretted hydrogen, sulphide of carbon, mercaptan, or phosphoretted bydrogen,
and phosphites.
For the preparation of the various metallic compounds numerous combinations
can be employed.
By suitable regulation of the temperatures of separation in the preparing
apparatus, and appropriate dilution of the mixtures of volatile compounds of carbon,
nitrogen, phosphorus, and sulphur to be used, coatings of varying electric con-
ducting power can be obtained.
The compounds of the refractory metals which have been found most suitable for
the purposes of this invention are,
The carburets of iron, platinum, iridium, palladium, molybdenum, chromium, and
manganese the nitrides of vanadium, tantalium, niobium; the phosphides of iron
platinum, iridium, palladium, molybdenum, chromium, manganese tungsten, and the
sulphurets of platinum, iridium, palladium, uranium, tantalium, molybdenum and
chromium.
The compounds of refractory metalloids with refractory metals or alloys thereof
which have been found most suitable are, the silicides of molybdenum tungsten,
chromium, platinum iridium, palladium &c.
The compounds of refractory metalloids with refractory carburets, nitrides,

page_text: phosphurets and sulphurets which have been found most suitable are those of
silicon and boron with the carburets &c. first above mentioned.
Having now particularly described and ascertained the nature of this inven
tion and in what manner the same is to be performed, we declare that what we
claim is-
1. The use, as metallic coatings for incandescence bodies of electric glow lamps,
of solid refractory compounds of refractory metals with either carbon, or nitrogen
or phosphorus or sulphur substantially as described.
2. The use, as metallic coatings for incandescence bodies of electric glow lamps,
of compounds of refractory metalloids with refractory metals or alloys thereof,
substantially as described."
3. The use, as metallic coatings for incandescence bodies of electric glow lamps,
of compounds of refractory metalloids and refractory metallic carburets, nitrides
phosphurets and sulphurets, such compounds being obtained by known chemical
processes with or without the aid of an eléctric current, substantially as described.
Dated this 3rd day of April 1891.
ABEL & IMRAY,
Agents for the Applicants.