An Improved Manufacture of Incandescence Bodies for Incandescence Gas Lamps.
Year: 1891

page_text: This print is in accordance with the Original Specification as it stands after
Amendment (under Section 18 of the Patents, &c., Act, 1883), as allowed by the
decision of the Comptroller General of the 5th day of November 1896..
An Improved Manufacture of Incandescence Bodies for Incandescence
Gas Lamps.
I, LUDWIG HAITINGER of Klosterneuburg near Vienna, Austria, Chemist do
hereby declare the nature of this invention to be as follows:-
:
My invention consists mainly in the production of incandescence bodies for
incandescence gas lamps by mixing together chromium oxide and aluminium oxide
whereby I obtain a body which when heated to incandescence in a Bunsen gas
flame, emits considerably more light than either of the said bodies when heated by
themselves.
This compound, so long as it is not heated to a high degree, has a green colora-
tion, like chromium oxide itself, and under those conditions it will not emit much
light, but when heated for some time to a high degree of incandescence, it becomes
rose-coloured, and under those conditions is highly luminous. Thus the light
emitting power may be said to be dependent upon the body assuming the said
characteristic rose-colour. To the above compound may be added other bodies
having more or less light emitting properties and even bodies that have no such
properties; thus the presence of small quantities of phosphoric acid or other fixed
acids, or of alkalies will not be prejudicial. In the above compound, the aluminium
oxide may also be replaced either wholly or partially by either magnesium oxide,
zirconium oxide, or calcium oxide, or other like oxides, giving incandescence bodies
which also have high illuminating powers, but I prefer to employ the first named
compound.
Also, the chromium oxide in the above named compound may be partially or
wholly replaced by manganese oxide and other similar oxides with similar results.
Thus the combination of calcium oxide and manganese oxide gives remarkably
strong light, and maintains this property for a longer time than pure calcium oxide.
The colour of this combination is yellowish.
It is an essential feature of these bodies that a very small proportion of chromium
oxide or manganese oxide-say one per cent., is sufficient to greatly increase the
light emitting power. Consequently an excess of aluminium oxide, or of the oxides
of zirconium, magnesium or calcium will not interfere with the light emitting power
of the bodies.
In preparing the above named incandescence bodies, the admixture of the com-
ponents may be effected either by mixing the oxides directly, or by first mixing the
salts of the said bodies together, and then converting such mixture into the oxide
condition by heating, and for this purpose any known process may be employed,

page_text: such as that for producing the " Welsbach" incandescence bodies, namely saturating
filaments with the mixed salt solutions, and then subjecting these to the requisito
heat for converting the salts into oxides. Or more or less porous bodies that
themselves possess a moderate degree of light emitting power may be saturated or
coated with the said salt solutions, and then heated so as to convert these into
oxidos, and thereby greatly increase the light emitting power of the said bodies.
Or again, a body consisting of the oxide of aluminium, calcium, magnesium or
zirconium, or a mixture of these, may be first formed in any suitable manner, and
this body be then impregnated with a salt of chromium, or manganese, and then
heated to incandescence.
DL: 10th day of Tanum 1901
An Improved Manufacture of Incandescence Bodies for Incandescence
Gas Lamps.
I, LUDWIG HAITINGER, of Klosterneuburg, near Vienna, Austria, Chemist, 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 —-
My invention consists mainly in the production of incandescence bodies for
incandescence gas lamps by mixing together chromium oxide and aluminium oxide
whereby I obtain a body which, when heated to incandescence in a Bunsen gas
flame emits considerably more light than either of the said bodies when heated by
itself.
This compound, so long as it is not heated to a high degree, has a green colora-
tion, like chromium oxide itself, and under those conditions it will not emit much
light, but when heated for some time to a high degree of incandescence it becomes
rose-colored, and under those conditions is highly luminous. Thus the light
emitting power may be said to be dependent upon the body assuming the said
characteristic rose colour.
To the above compound may be added other bodies having more or less light-
emitting properties and even bodies that have no such properties; thus the presence
of small quantities of phosphoric acid or other fixed acids, or of alkalies will not be
prejudicial.
In the above compound the aluminium oxide may also be replaced partially by
either magnesium oxide, or zirconium oxide, giving incandescence bodies which
also have high illuminating power, but I prefer to employ the first named
compound.
It is an essential feature of these bodies that a very small proportion of chromium
oxide, say one per cent., is sufficient to greatly increase the light-emitting power.
In preparing the above named incandescence bodies, the admixture of the com-
ponents may be effected, by first mixing the salts, (say nitrates, acetates, sulphates
or any other salts which will give oxides by heating to a high temperature) of the
said bodies together, and converting such mixture into the oxide condition by
heating and for this purpose the known process may be employed, for producing
the "Welsbach" incandescence bodies, namely saturating filaments with the mixed
salt solutions, and then converting the salts into oxides.
It may be remarked that the incandescence body so obtained differs from a body
of pure alumina made in the same way not only by its high light emitting power
but also by other properties, and that it is very similar to the incandescence bodies
now in use for the "Welsbach" process. Mantles made of pure alumina are brittle

page_text: even when they are heated and it is almost impossible to get them in suitable form,
whereas mantles of aluminium and chromium oxides possess, when heated to incan-
descence, a degree of softness which will enable their shape to be corrected to a
certain extent, and will also prevent them from being so easily destroyed when
in use.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that I make
no general claim to the manufacture of an incandescence body in the form of a cap
or hood in the manner set forth in the Specification No. 15286 of 1885, but what I
claim is :-
1. A manufacture of incandescence bodies consisting of a compound of aluminium
oxide and chromium oxide, produced by first mixing the salts of the said bodies and
then converting the mixture into oxide by heating, substantially as described.
2. In incandescence bodies such as are referred to in the preceding claim,
replacing the aluminium oxide partially by an oxide of zirconium, or magnesium
substantially as described.
ABEL & IMRAY,
Agents for the Applicant.