IMPROVEMENTS IN CARBON BURNERS FOR INCANDESCENT CONDUCTORS FOR ELECTRIC LAMPS, AND IN THE MEANS AND METHODS OF MANUFACTURE AND TREATMENT THEREOF, PARTLY APPLICABLE TO THE MANUFACTURE OF OTHER CARBON ARTICLES."
Year: 1881

page_text: LETTERS PATENT to Peter Jensen, of 33, Chancery Lane, in the County
of Middlesex, for an Invention of "IMPROVEMENTS IN CARBON BURNERS
FOR INCANDESCENT CONDUCTORS FOR ELECTRIC LAMPS, AND IN THE
MEANS AND METHODS OF MANUFACTURE AND TREATMENT THEREOF,
PARTLY APPLICABLE TO THE MANUFACTURE OF OTHER CARBON ARTICLES."
A communication from abroad by Thomas Alva Edison, of Menlo Park, in
the State of New Jersey, United States of America.
PROVISIONAL SPECIFICATION left by the said Peter Jensen at the Office
of the Commissioners of Patents on the 9th February 1881.
PETER JENSEN, of 33, Chancery Lane, in the County of Middlesex.
"IMPROVEMENTS IN CARBON BURNERS FOR INCANDESCENT CONDUCTORS FOR
ELECTRIC LAMPS, AND IN THE MEANS AND METHODS OF MANUFACTURE AND
TREATMENT THEREOF, PARTLY APPLICABLE TO THE MANUFACTURE OF OTHER
CARBON ARTICLES." A communication from abroad by Thomas Alva Edison,
of Menlo Park, in the State of New Jersey, United States of America.
One object of this Invention is to furnish a method or process by which pure and
flexible carbon may be manufactured in any desired shape, which method is
particularly applicable to the manufacture of carbon conductors for incandescent
electric lamps.
Thin sheet metal which will stand high temperature, for instance, sheet nickel
or cobalt, is cut or formed into the shape desired for the finished carbon, or
shaped wire may be used. One or several such formed pieces of metal are
suspended in a closed flask which is then heated to a high temperature; while in
this heated condition the vapor of a volatile carbon is passed through the flask
with the result that the carbon is deposited upon the metal shapes. For this
purpose the vapor of the bisulphide of carbon, the chloride of carbon, the volatile
parafins, or of naphtha is preferable. When a sufficient thickness of carbon has
been deposited, the flask is allowed to cool, atter which the carbon plated shapes
are immersed in some acid having an affinity for the metal used, and the metal
thereby eaten away, leaving the pure carbon in the desired shape.
...

page_text: Another method of producing carbon of any desired shape, say, in sheets, bows,
or other flat forms, or in the form of crucibles, dishes, or other hollow ware is as
follows: For sheets of carbon of any desired size a number of sheets of paper are
placed between plates of metal capable of withstanding a high degree of temperature.
The whole is then heated in a suitable flask or retort until all the constituents of
the paper except carbon are driven off, leaving the carbon in sheet form, flexible,
and of high non-conductive properties, exceedingly suitable for all uses where a
cheap and effective non-conductor is needed. Where special flat forms of carbon
are desired, the paper is cut into the shape desired, but of a size somewhat larger
than that of the desired carbon, so as to allow for the shrinkage attendant upon
carbonization.
The shaped paper is placed between plates, one of which preferably should be
provided with a groove or corresponding form, the whole is then carbonized as above
described. For hollow ware, such as crucibles, dishes, and other articles, paper may
be pressed into a mould by a plunger (the plunger and the mould having the shapes
desired for the interior and exterior of the article) and carbonized between the
moulds, or paper pulp or dampened paper may be struck up by a plunger and mould,
then dried and afterwards carbonized as before set forth.
The object of another part of this Invention is to furnish a method by means of
which the hydrogen may be removed from the incandescing conductors of electric
lamps; this element is the most difficult to eliminate from the carbons as it cannot
be removed except by using an inconveniently high temperature. The improved
method consists in passing through the flask in which the carbons are heating
chlorine gas or some other gas which combines readily with hydrogen but not with
carbon; the chlorine unites with the hydrogen, insuring its removal.
In incandescent electric lamps it is essential that every trace of oxygen so far as
possible should be removed from the enclosing globe in order to prevent the
disintegration or consumption resulting from heating a conductor in contact with
air. While a very high degree of vacuum is attainable by the means employed in
the "Edison" lamp, a degree sufficient to insure a long life to the conductor did it
not contain any air, experience has shown that enough air is occluded in the
conductor itself and in the clamps, which is given off when the conductor is brought
to the high degree of heat necessary for incandescence, to endanger if not continually
destroy it both by oxidization and electrical carrying. This portion of the Invention
consists of a method of creating carbon conductors to obviate this difficulty. The
parts of the lamp are assembled and united together in the manner which has been
heretofore practised in the manufacture of the "Edison lamp," and the lamp is then
attached to the exhausting apparatus.
When the proper degree of exhaustion has been reached a current is passed
through the carbon, preferably in such way as to gradually heat it to incandescence,
the operation of the exhausting apparatus being meanwhile continued, until it is
judged that practically all or as much as possible of the air is expelled by the heat
and removed by the exhausting apparatus.
As the clamps and the enlarged clamping ends are not heated so rapidly as the
rest of the carbon, the operation should be continued until these attain a sufficient
heat to drive out the occluded air and gas therefrom. In addition to the occluded
air and gas there is always, especially at the enlarged clamping ends, an amount of
watery vapor occluded.
In order to get rid of any harmful effect therefrom the heating should be carried
to a degree higher than necessary to give the incandescence for the candle power
intended normally for the lamp. It follows that if the lamp thereafter be used
at a less temperature than that at which it was treated, there will be nothing left
therein to be affected by such less temperature. The lamp is then sealed by the
fusion of the glass itself or by other suitable vitreous seal.
Some different means are sometimes desirable to properly remove the occluded
gases from the clamps and clamped portions of the carbon which may not be
To do this the heat from some
sufficiently heated by the passage of the current.

page_text: external source is concentrated on the clamps, as, for instance, from the sun or from
a voltaic arc lamp, which has the effect to drive off the occluded gases therefrom;
and these gases are then absorbed by a quantity of heated charcoal, the globe
afterward being sealed off.
In the so called "Edison" lamp, carbons for the incandescent conductors of electric
lamps are used made of fibrous vegetable materials, especially those like the bamboo
and other members of the family of " gigantic grasses," in which the body is
composed of a large number of exceedingly fine fibres lying parallel to each other
and having a minimum of foreign or extraneous matters. In the manipulation of
such attendant upon their conversion into carbons, it often happens that one or
more of the ultimate or unitary fibres or fibrillae, composing what is known as the
fibre, becomes ruptured or injured. This rupture is usually invisible to the eye, but
when the finished carbon is put to use, an arc is apt to form thereat, which
increasing finally destroys the carbon. The object of this part of the Invention is
to furnish a method of, and means for, treatment of the carbons so as to greatly
reduce or practically eliminate such danger. The carbons used are preferably
constructed with enlarged ends for clamping, small holes being formed in the
enlarged ends for the reception of the clamping screws. The fibres so constructed
and carbonized are hung in a suitable frame by means of pins passing through the
screw holes referred to.
The frame is placed in a flask capable of sustaining a high degree of heat) for
which purpose nickel is the best adapted), and a stream of vapor from a carbon
compound passed therethrough, while the flask and its contents are subjected to an
intense heat. The carbon vapor is one which will be decomposed by high heat,
the result being that there is a deposition of carbon upon the carbonized fibres,
filling any breaks and uniting the disjoined ends of any ultimate or unitary fibres
which have been ruptured or injured.
Another method by means of which carbon may be deposited at a weak or
defective point, to build it up so that its resistance will be the same as that of the
rest of the filament, is as follows:-The carbon is heated by focussing on the
defective point the rays from an external source of heat, such as the sun or a
voltaic arc lamp, while at the same time a carbon vapor from heated naphthaline
crystals or other carbon compound which is solid at ordinary temperatures, and
which are placed in a glass bulb connected by a tube with the lamp, is forced into
the globe which contains the carbon filament, and from which the air has been
exhausted. The vapor will deposit carbon upon the heated point, which will then
become a part of the carbon filament. The rest of the vapor is then removed by
means of the mercury pump.
If desired, a small amount of naphthaline crystals may be placed in the bottom
of the enclosing globe of the lamp, which will, when the lamp is in use, become
heated and volatilize gradually, and continuously supplying the waste of carbon due
to the process known as electrical carrying.
The lamp is afterwards sealed off, and is then ready for use.
The body of the carbons being a mere filament or thread like body, it is necessary
that they be provided with ends greatly enlarged, in order to afford a good
electrical contact with the clamps in which they are secured. With some materials,
such as paper, wood, bamboo, and the like, it is possible to make these enlarged
ends integral with, and a part of, the carbon itself by suitably shaping the material
prior to carbonization. Other fibres, however, such as, monkey bast, are simple
filaments, and the enlarged ends have to be built upon them.
The object of another portion of this Invention is to furnish a method and means
for making the necessary enlarged ends, and to that end it consists as follows:-
A carbon is so attached to electrical conductors that a current shall be passed
only through the portion or portions which it is desired to enlarge. It is then
placed in a glass globe or receiver having a small opening in its top. Connected
with the globe are means for generating and passing into the globe a stream of
by dro-carbon vapor capable of decomposition under high heat. In the electrical

page_text: circuit are placed resistances by which is regulated the pressure of the current
passing through the carbon. A shunt is arranged with a galvanometre and
resistances, so that the amount of current passing through the carbon may be
regulated. The vapor is allowed to pass through the globe until all the air therein
is displaced, the excess of vapor being burnt at the opening in the top of the globe.
The circuit being closed the portions of the carbon through which it passes are
heated thereby to incandescence, decomposing the vapor contiguous thereto, with
the result that the carbon therefrom is deposited upon the heated portion of the
conductor. The process is kept up until the portions referred to are sufficiently
enlarged.
Instead of the carbons being heated by the passage of a current they may be
heated by concentrating upon the portions desired to be enlarged the rays from a
voltaic arc lamp, the sun, or any other suitable source of heat, by means of a lens
or lenses properly arranged, the arrangements for surrounding the carbon during
the process with carbon vapor remaining the same.
Still another means of increasing the size and electrical conductivity of the ends
of the carbon in order to give more bearing surface to the clamps and secure
perfect. contact at the clamping electrodes is as follows:-An iron flask having a
tightly fitting cover is divided by a partition into two unequal parts. A number
of the carbon filaments are placed in the flask, the larger portions of each being
in one compartment, while the ends project through slits in the partition into the
other. The cover is then placed on the flask, and the whole is heated to a high
temperature in any suitable manner, after which, and while the carbons are still
very hot, hydrocarbon vapor is forced into the compartment containing the ends,
across the compartment and out the other side, by means of pipes provided for the
purpose.
During its passage across the ends of the heated carbon it will be decomposed
and will deposit other carbon thereon, which will become a part thereof, thus
enlarging the ends without increasing the size of the rest of the loop.
A.
Another method of ensuring a more perfect electrical conductivity at the clamps
consists in plating the enlarged ends of the carbon with a suitable metal.
galvano-plastic cell containing a solution of the metal is used having a support for
the carbon so arranged that it may be suspended with one or both ends submerged
in the liquid. An electrical circuit passes through the liquid of which the ends
of the carbon form the cathode, a suitable anode being placed in the circuit.
After the incandescing conductors are carbonized it is found sometimes that
they vary in resistance, and it is therefore necessary to reduce the resistance of
some in order that they may all be alike. The larger the carbon or the greater
its mass the lower the resistance, and consequently the way to reduce the resistance
is to increase either the size of the carbons or their mass, or both.
To do this the resistance of various carbons when cold is first tested, and those
in which it is lowest are found. The others must be reduced to nearly the same
point. This is done by heating them while they are exposed to a carbon compound
in a gaseous state, which will be decomposed by the heat and will deposit other
carbon on the carbon filaments until their size is increased and their resistance
diminished to the proper point. An apparatus for this purpose consists of a metal
flask or mold whose interior is of a convenient shape to contain the carbons, and
having combined with it means for passing through it an electric current for heating
it to incandescence, and a stream of carbon vapor for depositing carbon upon the
filaments. The time necessary for the operation may be determined by experiment,
carbons originally of high resistance requiring a longer time than those of greater
conductivity.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Peter Jensen in the Great Seal Patent Office on the 9th August
1881.
PETER JENSEN, of 33, Chancery Lanc, in the County of Middlesex.
"IMPROVEMENTS IN CARBON BURNERS FOR INCANDESCENT CONDUCTORS FOR
ELECTRIC LAMPS, AND IN THE MEANS AND METHODS OF MANUFACTURE AND
TREATMENT THEREOF, PARTLY APPLICABLE TO THE MANUFACTURE OF OTHER
CARBON ARTICLES." A communication from abroad by Thomas Alva Edison,
of Menlo Park, in the State of New Jersey, United States of America.
One object of this Invention is to furnish a method or process by which pure
and flexible carbon may be manufactured in any desired shape, which method is
particularly applicable to the manufacture of carbon conductors for incandescent
electric lamps. Thin sheet metal which will stand high temperatures, for instance,
sheet nickel or cobalt, is cut or formed into the shape desired for the finished
carbon, or shaped wire may be used. One or several such formed pieces of metal
are suspended in a closed flask, which is then heated to a high temperature. While
in this heated condition the vapor of a volatile carbon is passed through the flask
with the result that the carbon is deposited upon the metal shapes.
For this purpose the vapor of the bisulphide of carbon, the chloride of carbon,
the volatile paraffins, or of naphtha is preferable.
The vapor is passed through. the flask until a sufficient thickness of carbon has
been deposited upon the fornis, when the flask is allowed to cool.
When cool the carbon plated shapes are immersed in some acid having an affinity
for the metal used, and the metal thereby eaten away, leaving the pure carbon in
the desired shape.
This process is especially applicable to the manufacture of carbons for incandescent
electric lamps, in which case if desired the metal used may be in the shape of wire
or ribbon bent into the proper form, or may be cut from a sheet as before
described.
Another method of producing carbon of any, desired shape, say, in sheets, bows,
or other flat forms, or in the form of crucibles, dishes, or other hollow ware is as
follows:-
For sheets of carbon of any desired size a number of sheets of paper are placed
between plates of metal capable of withstanding a high degree of temperature.
The whole is then heated in a suitable flask or retort until all the constituents of
the paper except carbon are driven off, leaving the carbon in sheet form,
flexible, and of high non conducting properties, exceedingly suitable for all uses
where a cheap and effective non conductor is needed:
•
Where special flat forms of carbon are desired the paper is cut into the shape
desired, but of a size somewhat larger than that of the desired carbon, so as to
allow for the shrinkage attendant upon carbonization.
The shaped paper is placed between plates, one of which preferably should be
provided with a groove of corresponding form. The whole is then carbonized as
above described.
For hollow ware, such as crucibles, dishes, etc., paper may be pressed into a mold
by a plunger (the plunger and mold having the shapes desired for the interior and
exterior of the article) and carbonized between the molds; or paper pulp or
dampened paper may be struck up by a plunger and mold, then dried, and after-
wards carbonized as before set forth.
By this method carbons in flexible sheets are produced of any desired size, flat
carbons in any desired special shape, and carbon hollow-ware articles.

page_text: The object of another portion of this Invention is to furnish a method by means
of which the hydrogen may be removed from the incandescing conductors of
electric lamps. This element is the most difficult to eliminate from the carbons as
it cannot be removed even at the highest temperature to which the flask can be
brought without melting it.
One method of accomplishing this result is as follows:―
Chlorine gas, or some gas which combines readily with hydrogen but not with
carbon, is passed through the flask while the same is heated. The chlorine unites
with the hydrogen, ensuring its removal.
If desired, the process of carbonization may take place in one flask, and the
carbons then removed to another flask, where the chlorination may be effected.
In incandescent electric lamps it is essential that every trace of oxygen so far as
possible should be removed from the enclosing globe in order to prevent the
desintegration or consumption resulting from heating a conductor in contact with air.
While a very high degree of vacuum is attainable by the means set forth in the
Specification of Letters Patent No. 578, of February 10th, 1880, a degree sufficient
to ensure a long life to the conductor did it not contain any air, experience has
shown that enough air is occluded in the conductor itself and in the clamps, which
is given off when the conductor is brought to the high degree of heat necessary
for incandescence, to endanger if not eventually destroy it, both by oxidization and
electrical carrying.
This portion of the Invention consists in a method of treating carbon conductors
to obviate this difficulty.
The parts of the lamp are assembled and united together in the same manner
which has been heretofore described in the Specification of Letters Patent No. 578,
of February 10, 1880, and the lamp is then attached to the exhausting apparatus.
When the proper degree of exhaustion has been reached a current is passed through
the carbon, preferably in such way as to gradually heat it to incandescence, the
operation of the exhausting apparatus being meanwhile continued until it is judged
that practically all or as much as possible of the air is expelled by the heat and
removed by the exhausting apparatus.
The first heating will ordinarily throw out all gas and air included in the body
of the conductor itself, but at the clamps this is not so, as they are heated slowly
and then only by conduction, hence the operation should be continued long enough
for the clamps and clamped portions of the conductors to become hot enough to
drive out the occluded air and gas therefrom.
In addition to the occluded air and gas there is always, especially at the enlarged
clamping ends, an amount of watery vapor occluded. In order to get rid of any
harmful effect therefrom the heating should be carried to a degree somewhat or
much higher than necessary to give the incandescence for the candle power
intended normally for the lamp. It follows that if the lamp thereafter be used
at a less temperature than that at which it was treated, there will be nothing left
therein to be affected by such less temperature.
The lamp is then sealed by a fusion of the glass itself, or by other suitable
vitreous seal.
Some different means are sometimes desirable to properly remove the occluded
gases from the clamps and clamped portions of the carbon, which may not be
sufficiently heated by the passage of the current. To do this the heat from some
external source is concentrated on the clamps, as, for instance, from the sun or
from a voltaic arc lamp, which has the effect to drive off the occluded gases
therefrom, and these gases are then absorbed by a quantity of heated charcoal; the
globe afterward being sealed off.
This is illustrated in Figure 1 of the Drawings, which is an apparatus for this
purpose; and Figure 2, which is a modification thereof.
C is the enclosing globe of the electric lamp; c, being the carbon, and a, a, the
platinum clamps, in which the enlarged ends of the carbon are held. The lamp is
attached at X to the mercury pump A.

page_text: B is a glass bulb containing a quantity of charcoal, preferably a dense cocoanut
charcoal. This bulb is arranged so that it may be heated by means of a lamp.
A is the mercury pump by means of which air is exhausted from the lamp.
After as great a degree of vacuum as possible has been produced in this way, the
carbon is heated to incandescence by. means of a current of electricity, and the
occluded gases therein are thus driven off..
There still, however, remains, as stated, a quantity of gas in the clamps and the
enlarged ends of the carbons which are never heated to incandescence by the
passage of the current.
D is an electric arc lamp having a reflector n placed behind the light, and a
lens m placed before it, so that the full force of the rays will be concentrated on the
clamps a, a, and they will be heated to a high degree, driving out the occluded.
gases, which as they are driven out are removed by the mercury pump.
•
But a small amount of gas will still remain in the globe, and to remove it another
operation is necessary.
The bulb B is heated to a very high temperature, after which the lamp and bulb
are sealed off from the pump at c. They are then laid aside for twenty four hours,
during which time the carbon filament c is occasionally heated, after which the
carbon in the bulb will be found to have absorbed the residual gases from the
globe while cooling off. The lamp and bulb may then be separated at e by sealing
off.
The bulb B may be used for another lamp, the absorbed gas therein being driven
off by the application of heat to the bulb.
In Figure 2, an arrangement is shown which takes the place of the bulb B, and
which may be a permanent fixture of the pump A; E is a glass bulb, and fan arc
composed of a large piece of cocoanut charcoal, which is the absorbing material in
this case.
This does not required a lamp to heat it, as an electric current may be
used instead. Of course the chamber E need not necessarily be permanently attached
to the pump, but may be sealed off and again attached as in the case of the bulb B.
It has been heretofore fully explained in the Specification of Letters Patent,
No. 3765 of September 16, 1880, that exceedingly desirable carbons for the
incandescent conductors of electric lamps may be made of fibrous vegetable materials,
especially those like the bamboo and other members of the family of "gigantic
grasses "in which the body is composed of a large number of exceedingly fine fibers
lying parallel to each other, and having a minimum of foreign or extraneous
matters. In the manipulations of such attendant upon their conversion into carbons,
it often happens that one or more of the ultimate or unitary fibers or fibrillae
composing what is known as the fiber becomes ruptured or injured. This rupture
is usually invisible to the eye, but when the finished carbon is put to use, an arc is
apt to form thereat, which increasing finally destroys the carbon. The object of
this part of the Invention is to furnish a method of and means for treatment of the
carbons, so as to greatly reduce or practically eliminate such danger. The carbons
used are preferably constructed with enlarged ends for clamping, small holes being
constructed in the enlarged ends for the reception of the clamping screws.
fibers so constructed and carbonized are hung in a suitable frame by means of pins
passing through the screw holes referred to. The frame is placed in a flask capable
of sustaining a high degree of heat (for which purpose nickel is the best adapted),
and a stream of vapor from a carbon compound passed therethrough while the
flask and its contents are subjected to an intense heat. The carbon vapor is one
which will be decomposed by high heat, the result being that there is a deposition
of carbon upon the carbonized fibers, filling any breaks and uniting the disjoined
ends of any ultimate or unitary fibers which have been ruptured or injured.
The
Figure 3 represents partly in clevation and partly in section an apparatus for
this purpose, while Figure 4 is a view of the frame or rack detached from Figure 3.
C, C, C, are carbons made with enlarged ends, in which aro screw holes through
which are passed the pins p, p, by which the carbons are suspended in a rack or
frame F made of suitable side pieces f, f, supported on legs l, l.

page_text: On any suitable base B is placed the piece T which forms the bottom of a flask,
whose other portion is the cover or case H, within which is placed the frame F
loaded with carbons, as seen in Figure 3.
In a water tank T¹ is a reservoir R filled with a carbon compound capable of
vaporization. From R a pipe D provided with a stop cock leads to the interior of
the flask H.
The tank T¹ may be heated in any suitable manner; as shown, a faucet F admits
hot water therein, which causes the vaporization of the liquid in R, while F may
be used to admit cold water for lessening or entirely checking the production of
vapor..
Vapor is caused to pass through D into H, the surplus burning at o. At the
same time the flask and its contents are heated in any suitable furnace, the heat
causing a decomposition of the carbon vapor, and a consequent deposition of carbon
upon the carbonized fibers.
By this arrangement the vapor has free access to all parts of the carbonized
fibers, so that the carbon may be deposited upon the entire surface.
Another method by means of which carbon may be deposited upon a weak or
defective point to build it up, so that its resistance will be the same as that of the
rest of the filament, is as follows:―
The carbon is, heated by focussing on the defective point the rays from an
external source of heat, such as the sun or a voltaic arc lamp, while at the same
time a carbon vapor from heated naphthaline crystals, or other carbon compound
which is solid at ordinary temperatures, and which are placed in a glass bulb
connected by a tube with a lamp, is forced into the globe which contains the carbon
filament, and from which the air has been exhausted. The vapor will deposit carbon
upon the heated point, which will then become a part of the carbon filament.
Figure 5 of the Drawings is a view in section of an appropriate apparatus for
this purpose.
A is the incandescing electric lamp containing the carbon filament B, which has
been found defective at the point a. C is the mercury drop for forming the
vacuum in the lamp.
D is a glass bulb connected with the lamp by the tube b. It contains, crystals
of naphthaline or other carbon compound of a similar nature, and it may be heated
by means of the lamp E. F is a voltaic arc lamp, the rays from which, by means
of the reflectors c and d, may be focussed upon the defective point a of the
carbon B.
Heat being applied to the bulb which contains the carbon compound, it is
volatilized, and the vapor passes through the tube b into the lamp, where it deposits
an amount of carbon on the heated point of the filament. The rest of the vapor is
then removed by means of the mercury drop.
It is obvious that sources of heat other than that described, including the rays of
the sun, may be used.
If desired, a small amount of naphthaline crystals may be placed in the bottom
of the enclosing globe of the lamp, which will, when the lamp is in use, become
heated and volatilize gradually, and continuously supplying the waste of carbon due
to the process known as electrical carrying.
The lamp is scaled off at a, and is then ready for use.
The body of the carbon being a mere filament or threadlike body, it is necessary
that it be provided with ends greatly enlarged in order to afford a good electrical
contact at the clamps in which they are secured. With some material, such as
paper, wool, bamboo, etc., it is possible to make these enlarged ends integral with, and
a part of, the carbon itself, by suitably shaping the material prior to carbonization.
Other fibers, however, such as monkey bast, are simple filaments, and the enlarged
ends have to be built upon them. The object of another portion of this Invention
is to furnish a method and means for making the necessary enlarged ends, and to
that end it consists as follows:-A carbon is so attached to electrical conductors
that a current shall be passed only through the portion or portions which it is

page_text: desired to enlarge. It is then placed in a glass globe or receiver, having a small
opening in its top. Connected with the globe are means for generating and passing
into the globe a stream of hydro carbon vapor capable of decomposition under
high heat. In the electrical circuit are placed resistances by which is regulated the
pressure of the current passing through the carbon. A shunt is arranged with a
galvanometer and resistances, so that the amount of current passing through the
carbon may be regulated. The vapor is allowed to pass through the globe until all
the air therein is displaced, the excess of vapor being burnt at the opening in the top
of the globe. The circuit being closed, the portions of the carbon through which it
passes are heated thereby to incandescence, decomposing the vapor contiguous
thereto, with the result that the carbon therefrom is deposited upon the heated
portions of the conductor. The process is kept up until the portions referred to are
sufficiently enlarged.
In Figure 6 of the Drawings is shown an arrangement of means well calculated
to carry into effect the Invention, although the Invention is not limited to the
employment of the precise means therein illustrated. His the glass globe or holder
having an aperture o in its top, while the bottom thereof is sealed by the stopple S,
through which passes the support of the carbon C.
The carbon C is secured in temporary clamps B, a, a, of which a is connected to
conductor 1, and a¹ to conductor 2 of a circuit of any suitable source of electricity,
while the clamp B connects both limbs of the carbon; so that the circuit is via 1, a,
B, a', 2. The distance between B, a, and a¹ is equal to the portion of the carbon
which it is desired to enlarge.
V is a water reservoir in which is a tank T for containing a carbon compound
capable of vaporization under moderate heat. From it a pipe p leads to and
communicates with H.
P is a sten pipe having a branch pipe p¹ leading into V, and another leading into
the jacket Jaround p.
Steam being admitted thereto heats the water in V, causing the vaporization of
the compound in T, while the steam in jacket J heats 2 to a degree preventing
condensation therein.
R is an adjustable resistance placed in one branch of the circuit, so that the
electro-motive force or pressure of the current passing from a to B, and from B
to a, may be regulated.
G is a galvanometer and R' an adjustable resistance in a derived circuit to 1, 2,
forming a shunt to the carbon, so that the amount of current passing thereto may
be indicated and regulated.
The parts being in position, the vapor from T passes through H, the surplus
burning at o and preventing access of air to the interior, the circuit is closed at K,
whereupon the carbon between a and B and B and a¹ is heated, decomposing the
vapor and causing a deposition of carbon upon the heated portions. This deposition
is symmetrical and uniform, and is allowed to proceed until the portions are
sufficiently built up to afford good clamping surfaces.
Instead of a separate tank for the carbon compound, a small reservoir may be
made directly attached to and communicating with the globe or receiver H, and a
piece of solid carbon compound, such as solid naphtaline, placed in such small
attached reservoir.
Heat being applied thereto, carbon vapor passes into the globe and over and
around the carbon under treatment with the same result as in the other
construction.
Instead of the carbons being heated by the passage of a current, they may be
heated by concentrating upon the portions desired to be enlarged the rays from a
voltaic arc lamp, the sun, or any other suitable source of heat, by means of a lens or
lenses properly arranged, the arrangements for surrounding the carbon during the
process with carbon vapor remaining the same.
This modification may be reduced to practice by the use of the portion D of
Figure 1 with the part H of Figure 6.

page_text: In such case the carbon upon which it is desired to build up the enlarged ends
would be placed in H of Fig. 6, and carbon vapor passed therethrough, while
the rays of the lamp in D, Figure 1, or of other exterior source of heat would be
concentrated thereupon.
"
Still another means of increasing the size and electrical conductivity of the ends
of the carbon in order to give more bearing surface to the clamps and secure perfect
contact at the clamping electrodes, is as follows:-An iron flask has a tightly
fitting cover and is divided by a partition into two unequal parts. A number of
the carbon filaments are placed in the flask, the larger portion of each being in one
compartment, while the ends project through slits in the partition into the other.
The flask is then heated, after which carbon vapor is passed through the com-
partment containing the ends, and carbon is deposited thereon increasing their
size.
This is illustrated in Figure 7 of the Drawings, in which B is an iron flask or
mold having a cover A which fits tightly thereon. The flask is divided by the
partition g into two compartments c and d.
A number of carbon loops are placed in the flask as shown, the larger part
of each being in the compartment c, while the ends pass through slits in the
partition and project into the compartment d.
The cover is then placed on the flask and the whole is heated to a high
temperature in any suitable manner, after which, and while the carbons are still
very hot, the carbon vapor is forced into the pipe f and passes across the com-
partment & and out of the pipe e. During its passage across the ends of the
heated carbons it will be decomposed and will deposit other carbon thereon,
which will become a part thereof; thus enlarging the ends without increasing
the size of the rest of the loop, unless it is desired that this should be done, in
which case an aperture of the proper size may be left in the partition to allow a
portion of the vapor to pass through into the other compartment.
Another method of ensuring more perfect electrical conductivity at the clamps
consists in plating the enlarged ends of the carbon with a suitable metal.
A galvano-plastic cell containing a solution of the metal is used, having a support
for the carbon so arranged that it may be suspended with one or both ends
submerged in the liquid. An electrical circuit passes through the liquid of which
the ends of the carbon form the cathode, a suitable anode being placed in the
circuit. Figures 8 and 9 of the Drawings illustrate this.
In both Figures, A is an electro-depositing cell containing a suitable solution
of the desired salt, say nickel; 1, 2, are the conducting wires, 1 leading to the
anode B, while 2 connects with the carbon C which forms the cathode.
In Figure 8, D is a post upon an armn d of which is supported a saddle E on
which the carbon C is supported, so that both ends may be plated at once.
A number may be suspended from the saddle and plated simultaneously.
In Figure 9, a clamp F is shown in which one enlarged end of the carbon is
secured, the other dipping into the plating solution.
If desired to lessen the resistance in the circuit, it is evident that clamps may
be used, taking upon the carbons just above the solution, so that the most of the
resistance of the not to be plated portion of the carbons is cut out of the circuit.
As the plating takes in all the minute inequalities which may exist upon the
surface of the enlarged ends, it is in the best possible contact therewith, owing to
the tension of deposited metals, and a very perfect contact can be made between
the clamps and the metal coating, while at the same time the plating preserves the
enlarged ends from injury due to the clamps being pressed forcibly thereon. After
the incandescing conductors are carbonized it is found sometimes that they vary
in resistance, and it is therefore necessary to reduce the resistance of some in order
that they may all be alike. The larger the carbon or the greater its mass the lower
the resistance, and consequently the way to reduce the resistance is to increase
either the size of the carbons, or their mass, or both. To do this I first test the
resistance of various carbons when cold and find those in which it is lowest; the

page_text: others must be reduced to nearly the same point. This is done by heating them
while they are exposed to a carbon compound in a gaseous state, which will be
decomposed by the heat, and will deposit other carbon on the carbon filaments
until their size is increased and their resistance diminished to the proper point.
Figures 10, 11, and 12, illustrate this Invention; Figure 10 being a perspective
view of the apparatus; Figure 11, a plan or top view; and Figure 12, a
perspective view of a portion of the mold or flask in which the carbons are placed.
A is a flask or mold made of nickel, platinum, or carbon (the last being deemed
preferable because it can be made of paper, and carbonized into the proper shape),
having a tightly fitting cover B, a portion of which in the Drawing is broken
away to afford a view of the carbons a. The mold is supported on pillars C, D, E,
which rest on a suitable base F.
G, H, are pipes, through one of which vapor is admitted to the carbons a, and is
removed from the other.
The carbons being placed in the mold as shown, an electric current is passed
through the wires 1, 2, the pillars C, D, and the mold A, heating the inold, and
consequently the carbons, to a very high temperature. The carbon vapor is then
allowed to enter the pipe, and circulating around through the mold deposits carbon
on the heated filaments until their resistance becomes sufficiently reduced.
The time necessary for the operation may be determined by experiment, carbons
originally of high resistance requiring a longer time than those of greater
conductivity. Afterward the cover is taken off, and the carbons removed, when
the mold may be used again for other carbons.
It is not essential that the gas should be passed through the mold, as shown, by
means of pipes, but instead crystals of naphthaline or other carbon compound of
similar nature may be placed in the mold, and when it is heated they will vaporize
and deposit their carbon upon the filaments; or the cover B may be dispensed with,
and the mold placed in a receptacle filled with the vapor, the carbon of which will
be deposited upon the filaments when they are heated.
What is claimed is,-
First. The improved method herein described of forming carbon in definite shape,
consisting in depositing the carbon upon a metallic blank, and then removing the
inetallic portion, substantially as described.
Second. The method of forming carbon articles of a definite desired shape,
consisting in cutting or shaping the articles from paper, and then carbonizing the
shaped paper, substantially as herein set forth.
Third. The method of removing hydrogen from carbons, consisting in passing a
stream of chlorine or equivalent gas through the flask containing the carbons heated
to a bigh temperature, substantially as set forth.
Fourth. The method of treating carbon conductors for electric lamps herein
described, consisting in enclosing the conductor in a glass case or globe, exhausting
the air therefrom, heating the conductor by an electric current, and then hermetically
sealing the glass case or globe, substantially as set forth.
Fifth. The method of treating carbon conductors for electric lamps herein
described, consisting in enclosing the conductor in a glass case or globe, exhausting
the air therefrom, heating the conductor by an electric current to a higher degree
than that at which it is intended to ordinarily raise the conductor in use, and then
hermetically sealing the glass case or globe, substantially as set forth.
Sixth. The within described method of removing the occluded gases or vapors
from the incandescent conductors of an electric lamp, consisting in heating the same
in vacuum in the presence of a material which will absorb the gases or vapors
thereby eliminated, substantially as set forth.
Seventh. The within described method of removing occluded gases or vapors from
the enlarged ends and clamps of the incandescent conductor of an electric lamp,
consisting in heating such parts by external heat focussed or centred thereon in
the presence of a material which will absorb the gases or vapors thereby eliminated,
substantially as set forth,

page_text: Eigth. The combination of an incandescing electric lamp, means for producing a
vacuum within its enclosing globe, means for concentrating external heat upon the
incandescent conductor, and means for absorbing any gases or vapors given off by
the incandescent conductor, substantially as set forth.
Ninth. The method of treating carbonized conductors for incandescent electric
lamps, as herein described, consisting in subjecting the shaped carbonized conductors
to the action of high heat and a carbon vapor in a closed flask, wherein the vapor,
has free access to every portion of the carbonized conductors, substantially as set
forth.
Tenth. The within described process of building up or strengthening a defective
point in a incandescing conductor for electric lamps, consisting in heating that
point to a high temperature by concentrating thereon the heat from an external
source, and at the same time allowing a carbon vapor to enter the globe, and deposit
additional carbon on the heated point, substantially as set forth.
Eleventh. The combination with the carbon filament and its enclosing globe of a
chamber containing a solid carbon compound volatilizable at low heat, and means
for concentrating or focussing a high degree of heat upon any portion of the
filament, substantially as set forth.
Twelfth. An electric lamp, consisting essentially of a carbon filament, enclosing
globe, and conducting wires, provided with a solid carbon compound volatilizable
at low heat, substantially as set forth.
Thirteenth. The method herein described of forming enlarged ends upon carbon
conductors, consisting in forming an electrical circuit only through the portion
desired to be enlarged, thereby heating the same in a vessel, through which flows a
stream of vapor from a carbon compound, substantially as set forth.
Fourteenth. The combination of a receiving globe or chamber, means for passing
therethrough a stream of vapor from a carbon compound, and means for forming an
electrical circuit through any desired portion or portions of a carbon conductor
within said globe or chamber, substantially as set forth.
Fifteenth. The within described process of enlarging and increasing the electrical
conductivity of the clampod ends of the incandescing conductors of electric lamps,
which consist in passing over these ends a current of hydro-carbon vapor, while
they are at a high temperature, and separated from the rest of the carbon."
Sixteenth. A flask or mold divided by a partition into two parts, one of which is
provided with inlet and outlet pipes for the passage of hydro-carbon vapor,
substantially as and for the purpose described.
Seventeenth. A carbon for the incandescing conductor of an electric lamp, having
plated ends for clamping, substantially as set forth.
Eighteenth. The hollow mold or flask of an interior shape corresponding to the
carbons to be treated, and provided with means for passing therethrough a stream
of vapor, substantially as set forth.
Nineteenth. The combination with a hollow mold or flask for holding carbons to
be treated as described, of circuit connections for holding the mold or flask by
electrical incandescence, substantially as set forth.
.
In witness whereof, I, the said Peter Jensen, have hereunto set my hand and
seal, this Thirtieth day of July, A.D. 1881.
PETER JENSEN. (L.S.)