IMPROVEMENTS IN ELECTRIC LAMPS, AND IN THE MANUFACTURE OF CARBONS FOR THE SAME, . AND IN APPARATUS EMPLOYED IN SUCH MANUFACTURE
Year: 1881

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields, in the
County of Middlesex, Gentleman, for an Invention of "IMPROVEMENTS IN
ELECTRIC LAMPS, AND IN THE MANUFACTURE OF CARBONS FOR THE SAME,
. AND IN APPARATUS EMPLOYED IN SUCH MANUFACTURE." A communication
from abroad by Jean Baptiste Java Mignon and Stanislas Henri Rouart,
both of Paris, in the Republic of France.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson at the
Office of the Commissioners of Patents on the 5th August 1881.
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN ELECTRIC LAMPS, AND IN THE MANUFACTURE
OF CARBONS FOR THE SAME, AND IN APPARATUS EMPLOYED IN SUCH MANU-
FACTURE" A communication from abroad by Jean Baptiste Java Mignon and
Stanislas Henri Rouart, both of Paris, in the Republic of France.
This Invention relates to improvements in the manufacture and mode of
employing carbons or candles for electric lamps as hereinafter described.
In carrying out this Invention, carbons for electric lamps are constructed with a
core or wick as next hereinafter described. It has been observed that by making
the carbons hollow and filling them up either with another and smaller carbon of
different composition, or with a substance differing from that of which the carbon
proper is composed, introduced by any suitable means, a more steady and
regular light is obtained than that produced by the employment of solid carbons.
It has been found by experience that the same results and the same advantages
are obtained with solid carbons composed of pasty materials of different descriptions
moulded by being forced simultaneously through a suitably arranged moulding
orifice, and subsequently submitted to the operations usually employed to impart
the requisite qualities of homogeneity and density, and to ensure the brilliancy of
the light emitted.

page_text: The improved apparatus employed for this purpose consists of an internal mould
supported in position in the interior of a larger mould by means of suitable webs.
An annular or hollow ram works in the annular space between the external
surface of the inner mould and the internal surface of the outer mould, and a solid
ram works in the interior of the inner mould. The inner mould is contracted at
its lower extremity where it terminates within the outer mould in a small central
tube or orifice corresponding to the diameter of the core. The outer mould is also
contracted at its lower extremity and terminates in a contracted tube or orifice
concentric with but extending lower than the orifice of the inner mould and
corresponding to the external diameter of the carbon. The capacity of the moulds
is so calculated that the quantity of materials expelled through the respective
moulding orifices corresponds to the size of the carbons which it is desired to
produce.
On the descent of the rams the material issuing from the contracted orifice of
the inner mould is surrounded by the material expelled at the same time from the
larger and outer mould, and which in passing through the contracted orifice of the
latter is compressed around the material issuing from the inner mould and adheres
thereto by the time the carbon is compressed to its final dimensions, that is to say,
shortly before it issues from the tube of the outer mould.
A similar result may be obtained by employing a modification of the apparatus
as next hereinafter described. According to this modification the apparatus is
composed of a mould provided with a suitablo ram and terminating in a contracted
passage at its lower extremity. A chamber, also provided with a ram, is arranged
at the side of this mould and also terminates in a contracted passage communi-
cating with a tube so arranged as to discharge its contents in the centre of the
contracted passage of the mould hereinbefore described.
The material employed for the outer part of the carbon is placed in the mould,
and the material for forming the inner part or core is placed in the chamber at the
side. On the descent of the rams the materials are then expelled from the chamber
and from the mould under the same conditions as in the apparatus firstly
hereinbefore described. By arranging the chamber containing the materials
for the core at the side, as in the apparatus secondly hereinbefore described, the
advantage is obtained of enabling two independent rams to be employed, so
as to allow of the relative proportions of the material expelled from the mould
and from the chamber to be adjusted by regulating the relative speed of the
said rains.
The carbons may be made hollow and contain a column of air in lieu of the
wicks or cores hereinbefore described. These carbons may be obtained by the
employment of means similar to those employed in the manufacture of drain pipes,
and it is necessary that they should be perfectly dense and uniform in texture,
and be protected from atmospheric influence as hereinafter described.
Carbons thus prepared are found to yield results analagous, and in certain
respects superior to those obtained by the employment of carbons with solid
cores.
By means of this arrangement it is rendered possible to employ for the
production of the electric light very powerful sources of electricity which it has
not been heretofore possible to utilize, as the carbons beretofore employed would
in such case have required to be of such dimension as would be inadmissible
in practice. It is evident that the central orifice in the carbons may vary in size
according to the nature and dimensions of the carbons and the purposes to which
they are to be applied.
In order to preserve the carbons from contact with the air, it has been found
desirable in practice to cover the carbons employed in electric lighting with some
perfectly insulating material for various reasons, videlicet:-First. Whatever theory
is adopted respecting the distribution of the electricity on the interior of the
carbons, it appears certain according to numerous scientific experiments that it
manifests itself at the surface of bodies. Second. Waste of electricity ensues from

page_text: contact with the air, and this waste increases in proportion as the tension is
increased, and also with an increase of temperature, a condition which is carried to
extremes in the production of the electric light. Third. An insulating coating
certainly retards the oxidisation, that is to say, the combustion of the carbon.
For these reasons it is evident that a suitable and effectual insulator will have the
effect of preventing waste of electricity, that is to say, will increase the lighting
power, and will also increase the durability of the carbons. These two facts are
of the greatest importance, but the idea of covering the carbons is not new.
The means heretofore adopted with this object have yielded very incomplete
results, inasmuch as they failed to protect the exterior sufficiently to prevent the
formation of ash, and consequently to effectively retard the wear of the carbon.
According to this Invention, the desired result, that is to say, a really effective
coating impermeable to the air is obtained by covering the carbons with a vitreous
coating applied by means of an elevated temperature similar to the enamel
employed for covering porcelain and china. This coating may consist of any of
the coatings employed in these arts.
The colour may be varied by employing metallic oxides, which also serve in case
of need to improve the conducting power.
Excellent results are also obtained by enclosing the carbon in a tube of
extremely thin glass sealed to the former with any adhesive and insulating
substance.
The following advantages are also obtained by the employment of the enamelled
carbons, videlicet:-By means of these carbons it is rendered possible to make
electric candles composed of two concentric carbons, one being hollow and the other
solid, each one being enamelled and insulated from the other by a layer of air, or
simply by the enamel alone. Each of these carbons, which are of a size calculated
according to the work, is connected with the poles of a suitable generator of
electricity.
The enamelled carbons may also be employed in case it is required to arrange
two carbons in a vertical position parallel to one another or at an angle, such
carbons being of rectangular, circular, semicircular, or any other suitable shape.
It has been found that by arranging concave or convex cups or troughs of glass,
enamelled or otherwise, upon regulators at a suitable distance above and below
the point of ignition of the carbons, a remarkable increase in the light is obtained
by a peculiar incandescent effect.
It is evident that the cups must be supported at such a distance from the focus
as not to be liable to melt, and be so arranged as to remain in the required
relative position and adjust themselves to the motion of the carbons.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Henry Johnson in the Great Seal Patent Office on the 4th
February 1882.
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN ELECTRIC LAMPS, AND IN THE MANUFACTURE
OF CARBONS FOR THE SAME, AND IN APPARATUS EMPLOYED IN SUCH MANU-
FACTURE." A communication from abroad by Jean Baptiste Java Mignon and
Stanislas Henri Rouart, both of Paris, in the Republic of France.
This Invention relates to electric lamps and to the manufacture and employment
of carbons and candles for the same as hereinafter described.
And in order that the said Invention may be fully understood, I shall now
proceed more particularly to describe the same, and for that purpose shall refer to
the several Figures on the annexed Sheet of Drawings, the same letters of reference
indicating corresponding parts in all the Figures.
According to this Invention carbons for electric lamps are constructed with a
core or wick as hereinafter described. It has been found that by making the
carbons hollow and filling them up either with another and smaller carbon of
different composition or with a substance differing from that of which the carbon
proper is composed, a more steady and regular light is obtained than that produced
by the employment of solid carbons. Carbons of this description are generally
known as carbons with wicks or cores.
According to this Invention these carbons are manufactured by forcing pasty or
plastic materials of different descriptions simultaneously through suitably arranged
moulding orifices, the carbons so produced having, when finished, the requisite
homogeneity and density.
Figure 1 of the accompanying Drawings represents in vertical section an
apparatus constructed according to this Invention for carrying out this moulding
of the compound carbons. The said apparatus consists of an internal mould m
supported in position in the interior of a larger mould M by means of webs a. An
annular or hollow ring like ram B attached to a block or head A, works in the
annular space between the external surface of the inner mould m and the internal
surface of the outer mould M, and a solid ram C, also attached to the block A,
works in the interior of the said inner mould m. The said mould m is contracted
at its lower extremity, where it terminates, within the outer mould M in a small
central tube or orificet of a diameter corresponding to the diameter of the core of
the compound carbon to be produced. The outer mould M is also contracted at its
lower extremity and terminates in a contracted tube or orifice T, concentric with
but extending lower than the orifice t of the inner mould m, and corresponding in
diameter with the external diameter of the carbon to be produced. The capacity
of the moulds is so calculated that the quantity of materials expelled through the
respective moulding orifices t and T will correspond with and be sufficient for the
size of the carbons to be produced by the apparatus.
The material to form the outer part of the carbon or candle is placed in the
outer mould M, and the material to form the inner core is placed in the inner
mould m, both of these materials being in a plastic condition.
On the rams B and C being forced into the said moulds, the said materials are
forced respectively through the orifices T and t, the material issuing from the
contracted orifice t of the inner mould m being surrounded by the material
expelled at the same time from the outer mould M, which material in passing
through the contracted orifice T of the said mould is compressed around the
material issuing from the inner mould t, and is thereby caused to adhere thereto

page_text: by the time the carbon is compressed to its final dimensions, that is to say, shortly
before it issues from the tube T of the outer mould M.
Figure 2 of the accompanying Drawing represents a modified form of the
apparatus for producing the same results, wherein the rams for the two mould's
are separate. The mould M is provided with a ram P, the said mould terminating
at its lower part in a contracted passage or tube T. A chamber or mould m
provided with a ram p is situated at the side of this mould M, and also
terminates in a contracted passage communicating with a tube t, so arranged as to
discharge its contents in the centre of the contracted passage or tube T. The
tube t is represented in the Drawing as being a continuation of the lining of the
mould m.
The material employed for the outer part of the carbon is placed in the mould M,
and the material for forming the inner part or core is placed in the chamber or
mould m at the side. On the descent of the rams P, p, the materials are expelled
from the moulds M and m, through the passages T and t respectively under the
same conditions as in the apparatus illustrated in Figure 1.
By arranging the chamber containing the materials. for the core at the side, as
in the apparatus illustrated in Figure 2, the advantage is obtained of enabling two
independent rams to be employed so as to allow of the relative proportions of the
material expelled from the inould and from the chamber to be adjusted by
regulating the relative speeds of the said rams.
:
According to another part of this Invention the carbons are made hollow, and
contain a column of air in lieu of solid wicks or cores. They may be made by the
employment of means similar to those employed in the manufacture of drain pipes.
To secure good results it is necessary that they be perfectly dense and uniforin in
texture, and that they be protected from atmospheric influences, as hereinafter
described. Hollow carbons manufactured according to this Invention, with air
circulating in their interior, are found to yield results analogous and in certain
respects superior to those obtained by the employment of carbons with solid cores
or wicks. This is of great importance, as it enables hollow carbons of any shape
or description to be employed in the condition in which they leave the mould
without the addition of any other materials. Hence results considerable economy
and perfection in obtaining the products. By means of this arrangement it is
rendered possible to employ for the production of the electric light very powerful
sources of electricity, which it has not been heretofore possible to utilise, as the
solid carbons heretofore employed would in such case have required to be of such
dimensions as would be inadmissible in practice. It is evident that the central
orifice in the carbons may vary in size, according to the nature and dimensions of
the carbons and the purposes to which they are to be applied.
In order to preserve the carbons from atmospheric influences they are covered
with some perfectly insulating material. Whatever theory is adopted respecting
the distribution of the electricity on the interior of the carbons, it appears certain,
according to numerous scientific experiments, that it manifests itself at the surface
of bodies. Waste of electricity ensues from contact with the air, and this waste
increases in proportion as the tension is increased, and also with an increase
of temperature, a condition which is carried to extremes in the production of the
electric light. An insulating coating retards the oxidisation, that is to say, the
combustion of the carbon. By providing the carbons with a suitable and effectual
insulator, waste of electricity will be prevented, that is to say, the lighting power
and the durability of the carbons will be increased. Various means have been
proposed for covering the carbons, but they have hitherto yielded very incomplete
results, inasmuch as they failed to protect the surface sufficiently to prevent the
formation of ash, and consequently to effectually retard the wear of the carbon.
According to this Invention the desired result, that is to say, a really effective
coating impermeable to the air, is obtained by covering the carbons with a vitreous
coating similar to the enamel employed for covering porcelain and china, which the
carbons consequently resemble in appearance. This coating may consist of any

page_text: of the coatings employed in the manufacture of pottery, and is applied to the
carbons by means of an elevated temperature in a manner similar to that in which
enamel is applied to china, porcelain, and the like. The colour may be varied by
employing metallic oxides, which also serve in case of need to improve the con-
ducting power. Excellent results are also obtained by enclosing the carbon in a
tube of extremely thin glass sealed to the carbon with any adhesive and insulating
substance.
'
By means of these carbons it is rendered possible to make electric candles
composed of two concentric carbons, one being hollow and the other solid, each one
being enamelled and insulated from the other by a layer of air, or simply by the
enamel alone. Each of these carbons, which are of a size calculated according to
the work, is connected with the poles of a suitable generator of electricity. These
enamelled carbons may also be employed in case it is required to arrange two
carbons in a vertical position parallel to one another, or at an angle, such carbons
being of rectangular, circular, semicircular, or any other suitable shape.
The Invention relates further to an improvement in electric lamps, consisting in
arranging.concave or convex cups or troughs of glass, obscured or the like, or not,
upon regulators at a suitable distance above and below the point of ignition of the
carbons, a remarkable increase in the light is obtained by a peculiar incandescent
effect. It is evident that the cups must be supported at such a distance from the
are as not to be liable to melt, and be so arranged as to preserve the required
relative position.
Having now described and particularly ascertained the nature of the said
Invention, and the manner in which the same is or may be used or carried into
effect, I would observe in conclusion that what I consider to be novel and original
and therefore claim as the Invention secured to me by the hereinbefore in part
recited Letters Patent is,-
.
First. The manufacture for electric lamps of carbons with a core or wick by
moulding them at one operation, substantially as hereinbefore described.
Second. The apparatus or compound mould for making carbons with a wick or
core, the said apparatus or moulds being constructed or arranged substantially as
herein before described and illustrated in Figures 1 and 2 of the accompanying
Drawings.
Third. The hollow carbons with an air core, as hereinbefore set forth, for the
purpose of obtaining the same results as are obtained by the employment of the
ordinary carbons heretofore employed for electric lighting, and made with cores or
wicks, substantially as hereinbefore described.
Fourth. Preserving carbons for electric lighting from contact with the air by
coating them with enamel, substantially as hereinbefore described.
Fifth. The employment of vitrified or enamelled carbons in the manufacture of
candles for electric lamps, and composed of carbons arranged concentrically one
within the other, and separated by a layer of air or by the enamel coating only, or
in any other arrangement in which the carbons being placed vertically, obliquely,
or horizontally require to be insulated with regard to each other, substantially as
herein before described.
Sixth. The employment in electric lamps (for the purpose of augmenting the
light) of glass cups, substantially as hereinbefore described.
In witness whereof, I, the said John Henry Johnson, have to this my Speci-
fication set my hand and seal, the Third day of February, One thousand