Improvements relating to Compositions and Devices for use in the Manufacture of Filaments for Incandescent Electric Lamps.
Year: 1890

page_text: COMPLETE SPECIFICATION.
[Communicated from abroad by VINCENT MORGAN HOBBY, of the City and State
of New York, United States of America.]
Improvements relating to Compositions and Devices for use in the
Manufacture of Filaments for Incandescent Electric Lamps.
1, HENRY HARRIS LAKE, of the firm of Haseltine, Lake & Co., Patent
Agents, 45, Southampton Buildings, in the County of Middlesex, 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 manufacture of filaments for incandescent electric
lamps and comprises a composition of matter to be used for carbonizing the
filament.
The said invention also comprises an improved filament-carbonizing form.
The composition consists of the following ingredients combined in the proportions
stated
•
The ingredients are to be thoroughly mingled by agitation so as to form a paste.
When cold it is to be cut with a knife or some other sharp instrument.
The said filament to be carbonized, prepared as above described, is placed,
together with a lump of the above paste, in a graphite pot just large enough to
contain them and the frame upon which the filament is wound as hereinafter specified.
A graphite cover is then placed on the pot and made air tight by being sealed with
fireclay. The said pot is then placed in a large graphite pot of the same kind
leaving a space between the two of about two inches all around which is filled with
powdered graphite or lampblack or powdered charcoal (the first being preferred) a
cover is then sealed on the outer pot as was done with the inner one.
After the fire clay is thoroughly dry the pot is placed on the floor of the oven
and shavings packed around it, then the crucibles are thoroughly burned with coke
until the fire heats the pot to a white heat. They are then let cool gradually.
When the cover is removed the prepared carbon will be at the bottom of the inner
pot, the wood of the carbon block being substantially destroyed by the heat. The
paste burns during the process emitting a fume which settles around the filament
while carbonizing.
This completes the treatment of the filament. It is then cut in proper lengths
for use.
Better results seem to be obtained when the filaments are made of Irish flax or
Mexican grass as they appear to absorb the fume of the said paste, more than
filaments of other materials, but I do not limit my invention to its use with such
filaments only. I do not wind the said flax or grass around a carbon block as
generally done with carbonizing materials but instead thereof I use two carbon
pencils stuck together with two pieces of soft wood to avoid shrinkage the wood
only contracting to a certain extent, preventing the said flax or grass from shrinking
less than the dimension of the wood.
By the above composition and mode of treatment of the materials aforesaid a
filament for electric incandescent lamps can be made of higher efficiency than any
other now known to me and such filaments can be manufactured at a trifling cost
in any form or shape, and of any voltage or candle power.
ד

page_text: In the drawings I have shown an improved filament-carbonizing form,
Figure being a face view thereof, and
Figure 2 a transverse section.
A filament formed by my process is more flexible than those heretofore produced
and can be readily distinguished by the readiness with which they may be wound
or bent into varying shapes.
Having now particularly described and ascertained the nature of my snid
invention, 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 :-
First. The herein described composition or paste consisting of carbon, sugar and
mucilage substantially in the proportions specified.
Second. The herein described composition or paste consisting of carbon sugar,
mucilage and india ink in substantially the proportions specified.
Think. An improved filament-carbonizing form consisting of two separate carbon
pencils or sections and separate connecting means which prevents shrinkage of the
filaments to an extent any less than the contraction of the commeeting means
substantially as described.
Fourth. An improved filament-carbonizing form consisting of two carbon pencils
or sections connected by soft wood which prevents shrinkage of the filament to an
extent any less than the contraction of the wood, substantially as specified.
Dated this 2nd day of Sontorham 1900
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.