Improvements in and in the Manufacture of Incandescent Mantles.
Year: 1898

page_text: Date of Application, 1st Oct., 1898-Accepted, 31st Dec., 1898
COMPLETE SPECIFICATION (AMENDED).
Improvements in and in the Manufacture of Incandescent
Mantles.
A communication by OTHMAR LENZ, of No. 31 B, Luisenstrasse, Berlin, in the
Empire of Germany, Engineer..
I, WILLIAM PHILLIPS THOMPSON, F.C.S.,M.L.M.E., of the Agency for Foreign
Patent Solicitors, 6, Lord Street, Liverpool, and 6, Bank Street, Manchester, both in
the County of Lancaster, 118, New Street, Birmingham, in the County of Warwick,
and 322, High Holborn, in the County of Middlesex, Civil Engineer, 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 an improved incandescent mantle and to the method of
manufacturing such mantles.
The method, hitherto generally practised, of manufacturing incandescent mantles
may be considered as well known, it consists in preparing a solution of certain earths
or oxides of metals, mixing such solutions, impregnating with the mixed solution
woven fabrics or fibrous material, subsequently eliminating such fabrics or fibres by
combustion and thereby obtaining an extremely brittle, crystalline structure, which,
exposed to a considerable heat, developed an intense light. The said mode of
manufacturing incandescent mantles was based on the supposition, that the faculty
of emitting light of sufficient strength was due to the mixture of salts or earths
employed for the purpose.
Experience and a long series of experiments, however, have proved, that the
supposition before stated, is false, each of the salts or oxides is glowing for itself,
and only the mixture of the rays of light emitted is the cause of the excellent
illuminating effect visible. If, for instance, an incandescent mantle is previously
prepared by impregnating fabrics or fibrous inaterial with a solution of zirconium, or
thorium, or magnesium, or calcium and by eliminating the fibrous matter by com-
bustion, as usual, and if the mantle thus prepared is subsequently brought into a
solution of cerium, or chromium, or uranium, or into a mixture of such metallic-salts,
it will be found that the mantle, which, first yielded but a very poor light, has
obtained, by such subsequent treatment, a strong illuminating faculty.
Having established such facts and the object of this invention being this, to
provide an incandescent mantle not only of great illuminating power but also of
superior stability and duration, these desiderata are realised by proceeding as
follows:-
First, a solution of nitrate of cerium, soluble in solutions of other salts, is prepared
and said solution of nitrate of cerium is boiled, whereby part of the mixture of cerium

page_text: is precipitated and separated. This precipitated powder, containing about one fifth
of the mixture of cerium contained in the solution, is withdrawn and the remaining
fluid, containing about 80 per cent. of the mixture of cerium; now employed to
form a coating for incandescent mantles. Such coating is prepared and performed
in the following manner. From 10 to 20 gr. of the fluid before described (the 5
quantity varying according to the desired shade of white or yellow of the light to be
produced) are added to 1 litre of a fluid, which is commonly employed for stiffening
incandescent mantles after combustion for rendering such mantles capable of
transport. By coating an incandescent mantle, after combustion, with such stiffening
fluid, to which an extract of cerium, as before described, has been mixed, the 1
Baid mantle will obtain not only an excellent illuminating power, but also great
durability, and its faculty of emitting light does not depend on the particular kind
and nature of the salt or oxide, which had been used in, first, preparing the
incandescent mantle subsequently coated, as described. By further adding to the
said coating-fluid a sinall quantity of yttrium, the mantle, thereby, will become as
hard as stone.
In order to make the invention more fully understood, the saine will be explained
by describing one modification as an example.
An unprepared mantle of any known kind, consisting of woven or knitted fabrics
or fibrous inaterial is first impregnated with a solution containing:
30 parts of nitrate of zirconium,
3 parts of nitrate of calcium and .
1 parts of nitrate of magnesium.
After drying, the mantle is subjected to combustion, as usual, and by treating it
with a mixture of 0,04 % of chronic acid and of 0,06 % of nitrate of uranium, and
subsequently coating the mantle with a stiffening fluid, as described, containing an
extract of nitrate of cerium, an incandescent mantle will be obtained having the
combined faculties of a strong emission of a mild, agreeable, yellowish-white light, a
long durability, and a very strong construction, which latter may be further increased
by adding to the coating-fluid a small quantity of yttrium.]
Having now particularly described and ascertained the nature of the said in-
vention and in what manner the same is to be performed, as communicated to me
by my foreign correspondent, I declare that what I claim is :-
1. The method of preparing incandescent mantles, consisting in, first, impregnat-
ing a mantle of textile fibre with a known solution of an oxide or oxides of metal or
of earths, destroying the fibre by combustion and subsequently treating the mantle
with a solution of nitrate of cerium or a product or extract derived from such nitrate,
substantially as and for the purpose described.
2. The method of preparing incandescent mantles, consisting in first impregnating
a mantle of textile fibre with any known solution of metallic oxides or of earths,
destroying the fibre by combustion and subsequently treating the mantle with a
solution of a salt of chromium or a salt of uranium or a mixture of both, and finally
coating the mantle with a mixture composed of a fluid which is commonly employed for
stiffening incandescent mantles after combustion and a solution of a salt of cerium
or a product or extract derived from such salt, substantially as and for the purpose
set forth.
3. The method of preparing-incandescent mantles-consisting in, first impregnating
a mantle of textile fibre with any known-solution of an oxide or oxides of metal-or
of earths, destroying the fibre by combustion-and-subsequently treating-the-mantle
so-obtained with a solution of an-oxide-or-oxides-of-metal-capable--of-developing
illuminating power-when-heated, substantially-as-and-for-the-purpose-described.
4. The method of preparing incandescent-mantles,-consisting in first-impregnating
a-mantle of textile-fibre with any known solution of an oxide or oxides-of-metal,
destroying the fibre by combustion-and subsequently treating the--mantle-thus
obtained with a solution of an oxide-er oxides of metal capable of developing

page_text: illuminating power-when-heated,-with-an-addition-of yttrium-to-the-suid-solution,
substantially as and-for-the-purpose described.
5. The method, substantially as described, of--preparing incandescent mantles,
consisting in first impregnating a mantle of textile-fibre with a solution-containing
about-39-parts-nitrate of zirconium-3-parts--nitrate of calcium-and-1-purt
nitrate of magnesium, eliminating the fibrous material by-combustion, treating the
mantle-thus obtained-with-a-mixture of 0,01 %-of-chromic neid and 0,00%-of
nitrate of uranium, and finally, coating-the-mantle--with-a-solution-containing-
nitrate of eerium,-to-which-latter solution, a-solution-containing yttrium-may 1
added.
be
3., 6. As a new article of manufacture, incandescent mantles prepared essentially in
the manner described.