Improvements in and connected with Carbons for Electrio Lamps or for other purposes.
Year: 1894

page_text: Date of Application, 27th Sept., 1894-Accepted, 27th Oct., 1894
Improvements in and connected with Carbons for Electrio Lamps or
for other purposes.
I, EDWARD GOODRICH ACHESON, of Monongahela City, in the County of
Washington, and State of Pennsylvania, United States of America, Electrician,
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:—
My invention relates to carbons, and more especially to that class of carbons
which are adapted' for use in connection with the electric current, such as the points.
or rods for are lighting, the filaments for incandescent lighting, and other forms,
and it has for its object to produce an improved illuminating body which may be so
used, and which shall have the properties among others, of prolonged life and
greater efficiency, producing a greater light value for the electric energy utilised,
and to these ends my invention consists in a carbon or filament composed essentially.
of carbon, having associated with it and forming a part thereof, a certain proportion
of carbide of silicon.
.LIF
It is well known that many efforts have been made to improve the quality of
illuminating carbons, for the purpose of lengthening the life of the filaments, rods
or points, and also that many efforts have been made to produce a combination of
carbon with other substances for the purpose of producing more light for the
electrical energy consumed, and for this purpose many and various combinations of
materials have been made, both in the mass of the filament, rod or point, or in the
coating of the mass.
Without reciting all the efforts which have been made in this direction with
greater or less success, it has been one of the principal objects of my present
invention to produce an illuminating carbon containing a material having an
excessively high fusing point and equally difficult of oxidation, and at the same
time living a high luminescent value, as exhibited in the production of a greater
number of light-waves at a given temperature than the substances heretofore used,
these combined characteristics resulting in the production of an arc free from
vapors which have been produced in nearly or all former efforts, and also in the
production of an arc free from objectionable colors.
With these general statements of the objects and purposes of my invention, I.
will now proceed to describe the embodiment thereof and the manner in which my
invention is carried out, and it will be understood that while I have described what
may be considered as 'a preferable embodiment of my invention, I do not limit
myself to the preciso conditions or proportions herein set forth, as they may be
varied by those skilled in the art in accordance with the particular purposes for
which the carbons are intended, and the conditions under which they are to be
utilized.
In carrying out my invention I take preferably pure carbon, and preferably
reduce it to a finely pulverized condition, and also take carbide of silicon in a
similar condition, and thoroughly mix .the two together, and these may be united
by any appropriate or well known binding. material, such for instance, as tar.
While the proportions may be varied considerably, according to the purposes for
which the carbons are intended, a mixture of ninety per cent. of carbon and ten
per cent. of carbide of silicon, in the conditions above indicated produces efficient
and satisfactory results. When the carbons are to be used as rods, points, or other
forms, in an electric are, this mixture may be treated or manipulated in any of the

page_text: well known ways, by compression, baking, coating, etc., which need not be fully
set forth.
For some particular purposes, it will be found advisable to use a cored carbon
rod or point, the core being formed of substances other than carbon, and where
such form is desirable, as well as to get the full and complete effect of the
illuminating qualities of the carbide of silicon more distinctly separated from that
of the carbon, the ordinary cored carbon rod or point is used and the central space
is filled with the carbide of silicon, either alone or with a suitable binding agent.
In the use of the carbide of silicon in connection with the carbon of the
filaments for incandescent lighting, the carbide of silicon is intermingled with the
portions of the carbon at the surface and extending inward for any desired depth,
and it is intermingled and fixed in any suitable way, as for instance, the carbide of
silicon in a very fine powder or dust is mixed with and suspended in the oil used in
the well known oil bath, for the treatment and building up of the carbons, and in
the process of depositing the carbon from the oil bath onto the filament, the fine.
particles of carbide of silicon, being about and in contact with the filament, become
fixed to the filament simultaneously with the deposit of carbon and become a part.
of the filament, the amount of carbide of silicon tixed in the carbon being governed,
among other things, by the amount suspended in the oil. Other ways of combining
the carbide of silicon with the filament, of course, may be utilised, according to
the specific results intended to be produced.
Carbide of silicon is a product which was I believe first produced by myself,
and which has been formed at a temperature approximately that of the electric
arc, and which is, as a result, free from all volatile matters and as the result of
having already existed at these high temperatures is eminently fitted for the light-
giving body. It has also been demonstrated that it resists. oxidation to a greater
extent than any other known material, having resisted such chemical action when
highly heated and exposed to a stream of oxygen gas.
Associated with these two essential qualifications of infusibility and non-
oxidizability is a third equally valuable one, of luminescence, it producing a greater.
number of light-waves for the electrical energy consumed than those illuminating
bodies heretoforo used.
While carbide of silicon has the essential characteristics of an illuminating body.
as above stated, it is in itself deficient in the electrical conductivity necessary to
rods or points of are lights, and for that reason it is associated with carbon in their
formation.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manuer the same is to be performed, I.declare that what I
claim is :-
L
:
1. An illuminating body for electric lamps, comprising carbon associated with
carbide of silicon, substantially as described.
2. A carbon rod, point or filament for electric lamps or other purposes comprising
carbide of silicon as an illuminating body, associated with a body of relatively
high electrical conductivity, as carbon, substantially as described.
3. A carbon rod or point for electrio lamps or other purposes comprising an
outer body of carbon and a core of carbide of silicou, substantially as described.
1
•
PHILIP M. JUSTICE,
55 & 56, Chancery Lane, London, Chartered Patent Agent,
For the Applicant.