An Improved Process for Evacuating Incandescent Lamp Bulbs.
Year: 1894

page_text: Date of Application, 8th Aug., 1894
Complete Specification Left, 14th Feb., 1895-Accepted, 23rd Mar., 1895
PROVISIONAL SPECIFICATION.
An Improved Process for Evacuating Incandescent Lamp Bulbs.
I, ARTURO MALIGNANI, of Udine, in the Kingdom of Italy, do hereby declare
the nature of this invention to be as follows:-
The present invention consists of a process for evacuating incandescent lamp
bulbs.
Reference being made to the accompanying drawing: the bulb A of the lamp is
provided with a small glass tube T for the purpose of extracting the air and the
gases therefrom as hereinafter specified. Certain substances adapted under
circumstances to generate gases or vapours, such as arsenic, sulphur or iodine, are
then introduced into the interior of the bulb A advantageously at about the centre
of the tube T. The gases thus generated are intended to combine with the gases
generated by the filament of the lamp when brought to incandescence and form a
liquid or solid precipitation.
The most convenient method is to dissolve or dilute a powder in or with appro-
priate liquids, such as essence of tremandra, alcohol, or the like, in which case the
same can be applied most easily. The lamp is then connected with a vacuum
pump of any kind by means of the tube T and exhausted to the extent of about
two mm. of mercury. The vacuum having been obtained the lower part of the
tube is soldered up and the carbon filament is then brought to and intensive incan-
descence which has the effect of generating the gases contained therein; during
this time the part d containing the substance, is heated by suitable means, such as
a spirit lamp or the like which causes the said substances to be transformed in gases
or vapours, these latter then combine with the gases and vapours generated by the
filament to form a solid or liquid precipitation, so that an almost perfect vacuum is
obtained.
The introduction of a small quantity of ether vapours or other hydrocarbonates
into the lamp renders the combination of the above gases and vapours easier and
more energetic and assists the production of the vacuum. After having obtained
the vacuum it only remains to solder up the tube T at the lower part of the bulb
so that the bulb can be removed, and the lamp is ready for sale.
These operations can be performed very quickly as it is possible to obtain a
vacuum in from one to three minutes and even less, according to the nature of the
filament which varies. The quantity and nature of the gases generated by the
filament vary also so that it is necessary that the substances, the vapours of which
are to be precipitated in a solid or liquid state, should be carefully chosen, due
regard being bad to the nature of the filament and the proportion should be varied
accordingly.
Doted this 7th day of Angust 1894
F. BOSSHARDT & Co.,
Agents to Applicant.

page_text: I, ARTURO MALIGNANI, of Udine, in the Kingdom of Italy, 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:-
The present invention consists of a process for evacuating incandescent lamp
bulbs.
Reference being made to the drawings filed with the Provisional Specification:
the bulb A of the lamp is provided with a small glass tube T for the purpose of
extracting the air and the gases therefrom as "hereinafter specified. Certain
substances adapted under circumstances to generate gases or vapours, such as
arsenic, sulphur or iodine, are then introduced into the interior of the bulb A
advantageously at about the centre of the tube T. The gases thus generated are
intended to combine with the gases generated by the filament of the lamp when
brought to incandescence and form a liquid or solid precipitation.
The most convenient method is to dissolve or dilute a powder in or with appro-
priate liquids, such as essence of tremandra, alcohol, or the like, in which case the
same can be applied most easily. The lamp is then connected with a vacuum
pump of any
kind by means of the tube T and exhausted to the extent of about
two mm. of mercury. The vacuum having been obtained the lower part of the
tube is soldered up and the carbon filament is then brought to an intensive
incandescence which has the effect of generating the gases contained therein;
during this time the part d containing the substance, is heated by suitable means,
such as a spirit lamp or the like which causes the said substances to be transformed
in gases or vapours, these latter then combine with the gases and vapours generated
by the filament to form a solid or liquid precipitation, so that an almost perfect
vacuum is obtained.
The introduction of a small quantity of ether vapours or other hydrocarbonates
into the lamp renders the combination of the above gases and vapours easier and
more energetic and assists the production of the vacuum.. After having obtained
the vacuum it only remains to solder up the tube T at the lower part of the bulb
so that the bulb can be removed, and the lamp is ready for sale.
b
These operations can be performed very quickly as it is possible to obtain a
vacuum in from one to three minutes and even less, according to the nature of the
filament which varies. The quantity and nature of the gases generated by the
filament vary also so that it is necessary that the substances, the vapours of which
are to be precipitated in a solid or liquid state, should be carefully chosen, due
regard being had to the nature of the filament and the proportion should be varied
accordingly.
Having now particularly described and ascertained the nature of this
invention and in what manner the same is to be I declare that what I
claim, is :-
1st. A process for producing a vacuum in the bulbs of incandescent lamps
consisting in first introducing into a tubular elongation of said bulb suitable
substances capable of being gasified by heat and combining with the gases generated
by the filament when brought to incandescence to form solid or liquid precipi-
tations, then exhausting the said bulb by means of a pump and sealing the said
tubular elongation up, then bringing the filament to intensive incandescence and
simultaneously heating the substance in the elongation aforesaid and finally solder-
ing off the said elongation in the manner and for the purpose substantially as
described.

page_text: 2nd. In a process for producing a vacuum in the bulbs of incandescent lamps
consisting in first introducing into a tubular elongation of the bulb a substance or
substances having the qualities specified, exhausting the bulb by means of a pump,
sealing the said tubular elongation, then bringing the filament to intensive
incandescence and simultaneously heating the said substance or substances in the
elongation and sealing off the said elongation, the application in the bulb of ethers
or other suitable hydrocarbonates during the process in the manner and for the
purpose substantially as described.
Dated this 13th day of February 1895
F. BOSSHARDT & Co.,
4, Corporation Street, Manchester, Agents to Applicant.