MENTS IN THE MANUFACTURE OF CARBONS FOR INCANDESCENT ELECTRIC LAMPS
Year: 1882

page_text: LETTERS PATENT to John Jameson of Akenside Hill in the City of
Newcastle-upon-Tyne Consulting Engineer, for an Invention of IMPROVE
MENTS IN THE MANUFACTURE OF CARBONS FOR INCANDESCENT ELECTRIC
LAMPS
PROVISIONAL SPECIFICATION left by the said John Jameson at the Office
of the Commissioners of Patents on the 1st September 1882.
JOHN JAMESON of Akenside Hill in the City of Newcastle-upon-Tyne Consulting
Engineer, IMPROVEMENTS IN THE MANUFACTURE OF CARBONS FOR INCANDESCENT
ELECTRIC LAMPS.
My improvements in the manufacture of carbons for Incandescent Electric
Lamps consist first in depositing a film or thin layer of carbon from gas or vapour
upon a prepared surface of glazed porcelain or other suitable material by means
of a high degree of heat, the porcelain being so shaped as that the ultimate shape
of the carbon filament is produced by the deposit and that severance merely of the
deposit in one direction shall produce the filament and next in the thickening of
the ends of the filament formed by means of further deposit produced by exposure
of the ends of the filaments only in suitable circumstances. Both parts of my
invention may be used either together or seperately. I may for instance produce
the deposit by my invention and thicken the ends otherwise, or I may produce the
carbon filament otherwise and thicken by my invention.
-
I prefer to employ for the deposit a trough or series of troughs of porcelain of
U shape protected as to the outside by being embedded up to the top in a layer
of charcoal, refractory sand, or ground pottery contained in a shallow vessel of
refractory material, as regards heat. I construct a reverberatory or other suitable
furnace with an opening and pipe so as to convey the gas to be decomposed
through an opening in the middle of the shallow vessel before referred to or at the
side of it and I provide a cover of similarly refractory material so as to protect the
contents of the shallow vessel from the action of air or furnace gasses.-In these
circumstances if the apparatus I have described be highly heated and gas supplied
a deposit of hard carbon will occur in all exposed parts and when it is adequate

page_text: I allow the apparatus to cool slowly either by withdrawing from the furnace or
otherwise. The film contracting in cooling, has, by the mobility of the layer of
charcoal or other material described and by the shape of the trough room for this
contraction sideways, or in one direction and by imperfect adherence to the glazed
surface of the porcelain has room for contraction the length way of the troughs or
in the other direction. When it is sufficiently cooled I run into each trough
shellac or any other suitable material capable of protecting it from injury and to
give it stability in cutting or if allowed to become quite cold I use melted shellac
or other suitable material and I then separate the contents of each trough and cut
the deposit into the desired pieces.
For the thickening of the ends I partially immerse the filaments in a layer of
charcoal, or ground pottery or other suitable material leaving the ends to be
thickened projecting and I then expose them to the action of heat and gas or
suitable carbonaceous vapour just as in forming the deposit before described the
effect of which is to produce the desired thickening.-I do this simply by itself or
I may facilitate the process by the insertion in the layer of charcoal before
described of a short extra piece or pieces of filament in close proximity to the end
of the filament to be thickened so as that the deposit may join the two or more
pieces together, and I may also introduce a piece or pieces of platinum wire so as
to be joined by means of this deposit to the filament of carbon.-I may also
construct the troughs of porcelain before described with a series of suitable grooves
or channels transversely of such shape as that the mere uniform grinding off of
projections on the deposit may seperate a series of filaments with enlarged ends
which may be further increased in dimensions or not by the process already
described.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Jameson in the Great Seal Patent Office on the 27th February
1883.
JOHN JAMESON of Akenside Hill in the City and County of Newcastle-upon-
Tyne, Consulting Engineer. IMPROVEMENTS IN THE MANUFACTURE OF CARBONS
FOR INCANDESCENT ELECTRIC LAMPS.
My improvements in the manufacture of carbons for Incandescent Electric
Lamps consist first in depositing a film or thin layer of carbon from gas or vapour
upon a prepared surface of glazed porcelain or other suitable material by means of
a high degree of heat, the porcelain being so shaped as that the ultimate shape of
the carbon filament is produced by the deposit and that severance merely of the
deposit in one direction shall produce the filament, and next in the thickening of
the ends of the filaments formed by means of further deposit produced by exposure
of the ends of the filaments only in suitable circumstances.-Both parts of my
Invention may be used either together or seperately. I may for instance produce
the deposit by my Invention and thicken the ends otherwise or I may produce the
carbon filament otherwise and thicken by my Invention.-I prefer to employ for
the deposit a trough or series of troughs of porcelain of U shape, the U placed as
it is written, protected as to the outside by being embedded up to the top in a
layer of charcoal, refractory sand or finely ground pottery contained in a shallow
vessel of refractory material as regards heat.
I construct a reverberatory or other suitable furnace with an opening and pipe
so as to convey the gas to be decomposed through an opening in the middle of the
shallow vessel before referred to or at the side of it, and I provide a cover of
similarly refractory material so as to protect the contents of the shallow vessel
from the action of air or furnace gasses, and so arranged as that the hydrocarbon
gas or vapour is kept supplied under the cover I speak of to the contents of the
shallow vessel wherein is contained the U shaped troughs.-In these circumstances
if the apparatus I have described be highly heated and gas supplied a deposit of
hard carbon will occur in all exposed parts, and when it is adequate I allow the
apparatus to cool slowly either by withdrawing it from the furnace or otherwise.--
The film contracting in cooling has by the mobility of the layer of charcoal or
other material described room for this contraction side ways and by imperfect
adherence to the glazed surface of the porcelain has room for contraction the
length way and the vertical way of the troughs.-When it is sufficiently cooled I
run into each trough shellac or any other suitable material capable of protecting it
from injury, and to give it stability in its seperation from the troughs and in
cutting and I then seperate the contents of each trough and cut the deposit
into the desired pieces by means of emery or sand wheels or other convenient
arrangement.
For the thickening of the ends I partially immerse the filaments in a layer of
charcoal or ground pottery or other suitable material in a similar furnace arrange-
ment to that already described leaving the ends to be thickened projecting, and I
then expose them to the action of heat and gas or suitable carbonaceous vapour
just as in forming the deposit before described the effect of which is to produce
increased deposit and thus the desired thickening.-I do this simply by itself or I
may facilitate the process by the insertion in the layer of charcoal before described
of a short extra piece or pieces of filament in close proximity to the end of the
filament to be thickened so as that the deposit may join the two or more pieces
together and by this means may also attach wires of platinum namely by
inserting them so as to be attached by deposit to the filament itself.

page_text: I may also construct the troughs of porcelain before described with a series of
suitable grooves or channels transversely of such shape as that the mere uniform
grinding off of projections on the deposit may seperate a series of filaments with
enlarged ends which may be further increased in dimensions or not by the process
already described. The enlarged ends must be manifestly in this arrangement not
in the first instance thickened ends but widened ends, I have described a form of
furnace and troughs and mode of operation which I consider the most convenient
but the operation may be carried out in almost any form of furnace and successfully
in even an ordinary coke oven by burying a box containing the articles on which
the deposit may be desired, amongst the coal to be coked with no special provision
beyond casual interstices for supply of gas.
I do not claim any special form of furnace or special form of trough in or on
which the deposit may be formed but what I claim as my Invention is 1st the
formation of Carbon filaments wholly of deposited carbon with or without thickened
or widened ends substantially as described.
And 2nd the thickness of the ends of carbon filaments with deposited carbon
substantially as described.
In Witness whereof I the said John Jameson have hereunto set my hand
and seal this twenty second day of February, in the year of our Lord, one
thousand eight hundred and eighty three.
Witness
JOHN BOWMER
Clerk
Forest Hall.
J. JAMESON (L.S.)