Improvements in Filaments of Electric Incandescent Lamps.
Year: 1896

page_text: Date of Application, 24th July, 1896
1007
Date of Application, 24th July, 1896
Complete Specification Left, 22nd May, 1897 Accepted, 20th June, 1697
PROVISIONAL SPECIFICATION.
Improvements in Filaments of Electric Incandescent Lamps.
I FRANK EUSTACE WILKINS BOWEN of Selwood, Mount Avenue, Ealing, in
the County of Middlesex, Gentleman, do hereby declare the nature of this
invention to be as follows:-
In order to obtain a filament that may be worked at a higher efficiency than
the ordinary carbon filament without rapid disintegration, I incorporate in the
body of the cellulose from which the filament is formed, metallic borates, such as
the borates of Al., Mg., Zr., Ca., or other suitable metals.
After carbonization, the filaments are dipped into solutions of metallic salts,
and dusted with finely powdered oxides or salts (or both), prior to flashing.
The filaments are then flashed in any suitable carbonaceous vapour or gas.
Preferably I flash or incandesce the filaments according to the process described in
the Specification accompanying the application for Patent No. 3213%, that is to say,
in the presence of the borates of the alcohols; or I may flash in the vapour of
ethyl or methyl silicates, or in the vapour of a mixture of the ethereal silicates and
borates.
Dated this 24th day of July 1896.
NEWTON & SON,
Agents for the Applicant.
Improvements in Filaments of Electric Incandescent Lamps.
I FRANK EUSTACE WILKINS BOWEN of Selwood, Mount Avenue, Ealing in
the County of Middlesex, Gentleman, do hereby declare the nature of this inven-
tion and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement :-
In order to obtain a filament that may be worked at a higher efficiency than the
ordinary carbon filament without rapid disintegration, I incorporate in the body of
the cellulose from which the filament is formed, metallic borates, such as the borates
of aluminium, magnesium, zirconium, strontium, or calcium, or of other suitable
metals of a refractory character.
This incorporation may be effected mechanically by mixing about 10% of the
metallic borate in a powdered state with the cellulose, prior to squirting. I prefer,
however, to adopt the following method.
I take the cellulose filament, squirted and washed in any suitable way, and I
soak it in a solution of a salt, preferably the nitrate of the metal being used.
I then soak it in a solution of boric acid, and finally dry, wind, carbonize, and flash
in any suitable and convenient manner.
During these operations, or some of them, a reaction takes place between the
metallic salt and the boric acid, which results in the production of a filament

page_text: wherein is incorporated the borate of the metal, which incorporation gives to the
filament a high degree of efficiency.
The salt of the metal is most conveniently dissolved in water, and the boric acid
in alcohol.
In the finished product it is preferred that about 5% of the metallic borate
should be found to give satisfactory results.
To this end, therefore, I have employed solutions containing approximately 7 to
10%
of the metallic salt, and 2 to 3% of the boric acid. I do not, however,
propose to confine myself precisely to these proportions.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
· claim is :-
1. The improved filament for incandescent lamps, in the body of which are
incorporated metallic borates, substantially as described.
2. The method hereinbefore described, of incorporating metallic borates in the
filaments, such method consisting in soaking the cellulose in solutions of the nitrate
or other soluble salt of the metal and of boric acid, and in causing the same to
re-act, so as to produce the borate, as set forth.
Dated this 17th day of May 1897.
NEWTON & SON,
Agents for the Applicant.