An Improvement in Incandescent Electric Lamps.
Year: 1892

page_text: Date of Application, 25th Oct.. 1892
Complete Specification Left, 25th Ju'y. 1893-Accepted. 2nd Sept., 1993
TOVISIONAL DEUIFICATION.
[Communicated from abroad by THE WESTINGHOUSE ELECTRIC AND MANG-
FACTURING COMPANY, of Pittsburg, Pennsylvania, United States of America.]
An Improvement in Incandescent Electric Lamps.
I, OLIVER IMRAY, of No. 28 Southampton Buildings, Chancery Lane, in the
County of London, Chartered Patent Agent, do hereby declare the nature of this
invention to be as follows:-
The invention relates to the construction of the bulbs of an incandescent electric
lamp in such a manner that it can be opened giving access to the filaments and
wires, and thus the greater portion of the bulb and also the leading in wires can be
used repeatedly.
For this purpose, I construct the bulb in two parts, the principal portion of glass,
while the rest is composed of a soluble material, such as alkaline silicate, which can
be united to the glass portion making an air tight chamber, but which can be
dissolved away from the glass portion by immersing it in a suitable solvent, leaving
the glass portion intact.
The soluble portion of the bulb may be combined with the glass portion in
various ways.
A. convenient way is to form the bulb with a tubular neck, to seal the wires in a
stem of the soluble material, this stem being either solid or tubular, to insert this
stem in the neck, and fuse it to the edge of the neck. Instead of the platinum
wires employed for sealing in glass, iron wires may be used for sealing into the
soluble compound.
After the lamps have been in service and have become unfit for farther use, it
may be immersed in a suitable solvent, such for instance, as hot water with or
without the addition of alkalies or acids, and the soluble portion gradually becomes
dissolved or disintegrated, so that the stem and wires can be removed, the glass
portion being left in condition to be used again.
The soluble portion, may, if desired, be protected from the action of moisture by
coating it with a varnish or suitable protecting material which is impervious to
moisture.
Dated this 25th day of October 1892.
ABEL & IMRAY,
Agents for the Applicant.
COMPLETE SPECIFICATION.
An Improvement in Incandescent Electric Lamps.
1, OLIVER IMRAY of No. 28 Southampton Buildings, Chancery Lane in the
County of London, Chartered Patent Agent 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 the construction of the bulb of an incandescent electric
lamp in such a manner that it can be opened giving access to the filament and
wires, and thus the greater portion of the bulb and also the leading in wires can be
used repeatedly.
For this purpose, I construct the bulb in two parts, the principal portion of glass,
while the rest is composed of a soluble material which can be united to the glass
portion making an air tight chamber, but which can be dissolved away from the

page_text: glass portion by immersing it In a suitable solvent, leaving the glass portion
intact.
1 employ certain compounds of alkali with silica to form the soluble portion of
the lamp, preferably the supporting stem, that is to say, the portion which carries
the leading-in wires.
These compounds are soluble in water, especially in hot water, when heated
they readily unite with the wires and also with the glass, making air tight
joints.
Although it is preferred that only the portion surrounding or carrying the
leading in wires should be of the soluble material, other portions of the bulb
may also be made of the soluble material.
As suitable soluble material I employ a silicate of soda corresponding approxi-
mately to the formula 2 Na,O + 5 SiO2, but various other combinations of alkali
with silica will work satisfactorily.
The selection of the compound depends largely upon the composition of the
glass portion of the bulb. The greater the proportion of the alkali to the silica,
the softer is the resulting compound.
The compound 4 Na2O + 5 SiO, makes a perfect union with platinum leading in
wires and also unites with glass having a comparatively low fusing point. I have
also used the compound Na,O 4 SiO,, and others such as 2 Na₂O 7 SiO, and
Na₂O 4 SiO, with more or less silica in proportion to the alkali. In general it
may be stated that the higher the fusing point of the glass the greater should be
the ratio of the silica to the alkali.
As boron is in some respects analogous to silicon, a proportion of boric acid,
which has the formula B₂O, may be incorporated with the compound.
The soluble portion of the bulb may be combined with the glass portion in
various ways.
A convenient way is to form the bulb with a tubular neck, to seal the wires in a
stem of the soluble material, this stem being either solid or tubular, to insert this
stem in the neck, and fuse it to the edge of the neck. Instead of the platinum
wires employed for sealing in glass, iron wires may be used for sealing into the
soluble compound.
After the lamp has been in service and has become unfit for further use, it may
be immersed in a suitable solvent, such for instance, as hot water with or without
the addition of alkalies or acids and the soluble portion gradually becomes dissolved
or disintegrated, so that the stem and wires can be removed, the glass portion being
left in condition to be used again.
The soluble portion may, if desired, be protected from the action of moisture by
coating it with a varnish or suitable protecting material which is impervious to
moisture.
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. A bulb for an incandescent electric lamp consisting partly of glass and partly
of a soluble compound united air tight to the glass, substantially as and for the
purpose set forth.
2. A bulb for an incandescent electric lamp having its stem which holds the
wires made of soluble material and united air tight to the bulb, substantially as
described.
Cr
1000
ABEL & IMRAY,
Agents for the Applicant.