Improvements in the Manufacture of Carbons for Electric Arc Lamps.
Year: 1891

page_text: Date of Application, 15th July, 1891
Complete Specification Left, 7th Apr., 1892-Accepted, 15th July, 1892
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Carbons for Electric
Arc Lamps.
A communication from THE RHEINISCHE FABRIK FÜR ELEKTRISCHE BOGEN-
LICHTKOHLE:,,W. GRÜDELBACH, of Dinslaken, Germany.
I, WILLIAM LLOYD W18E of No. 46 Lincoln's Inn Fields, in the County of
London, Consulting Engineer and Patent Agent, do hereby declare the nature of
this invention to be as follows :,..
This invention has for object to produce a carbon rod which will afford, under
the action of the electric arc, an extremely steady light of great illuminating power,
will burn for a long period, and will be consumed uniformly without formation of
slag, and with the production of but very little asb.
Many methods have been devised for the production of impregnated carbons for
giving a steady light the most important consisting in making the carbon tubular
and then filling the interior with a liquid or pasty mixture of finely divided carbon
and certain substances employed in its preparation, such mixture being forced under
pressure into the aperture and thence into the pores of the rod.
Carbons produced by this method however have, like cored carbons made
according to other somewhat similar methods, the serious disadvantage that the
substances employed for the impregnation penetrate the entire carbon rod, or the
greater portion of it, and, during burning, form slag.
Besides this disadvantage, such rods have the further drawback that the core is
not sufficiently firm, but is extremely porous this being caused mainly by the
intense drying of the rod after the core has been inserted. Furthermore when
such a rod is in use, gases collect in the recesses in the core, and in escaping have
an injurious influence on the arc light as respects its steady burning.
According to this invention these disadvantages are obviated and there is
provided a carbon having a thoroughly dense and firm core, whilst the carbon
proper is made of the finest graphite-containing carbon without impregnation with
the substances formerly employed for the purpose of obtaining steady burning.
For this purpose 'hollow rods, that is to say, rods formed with a core hole are
made by pressing, and are then baked, after which the substance employed for the
core is charged into the core hole, a second baking being unnecessary.
The charging of the core is effected. by means of a machine having a plunger
capable of pressing the dry mixture of finely pulverized carbon and the substances
serving for its preparation into the core hole the form of the plunger in cross
section being such that when moving in the core hole, air therein can escape easily
und quickly past the plunger.
The choice of the dry substances to be mixed with the carbon depends on the
particular use for which the carbon is intended.
The carbons produced in this mauner have an extremely firm and uniform
core.
..
:
The core hole is preferably of circular form in cross section, but may be.
polygonal.
Dated this 15th day of July 1891.
TTAVA WIL
W. LLOYD WISE,
Per F. J. Brougham.

page_text: COMPLETE SPECIFICATION.
Improvements in the Manufacture of Carbons for Electrio
Arc Lamps..
"
A communication from THE RHEINISCHE FABRIK FÜR ELEKTRISCHE BOGEN-
LICHTKOHLE: W. GRÜDELBACH, of' Dinslaken, Germany.
1, WILLIAM LLOYD WISE of No. 46' Lincoln's Inn Fields, in the County of
London, Consulting Engineer and Chartered Patent Agent, 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 has for object to produce a carbon rod which will afford; under
the action of the electric arc, an extremely steady light of great illuminating power,
will burn for a long period, and will be consumed uniformly without formation of
slag, and with the production of but very little ash.
Many methods have been devised for the production of impregnated carbons for
giving a steady light, the most, important consisting in making the carbon tubular'
and then filling the interior with a liquid or pasty mixture of finely divided carbon
and certain substances employed in its preparation, such mixture being forced under
pressure into the aperture and thence into the pores of, the rod.
Carbons produced by this, method however have, like cored carbons made
according to other somewhat similar methods, the serious disadvantage that the!
substances employed for the impregnation penetrate the entire carbon rod, or the
greater portion of it, and, during burning, form slag.
Besides this disadvantage, such rods have the further drawback that the core is
not sufficiently firm, but is extremely porous, this being caused mainly by the
intense drying of the rod after the core has been inserted. Furthermore-wlien
such a rod is in use, gases collect in the recesses in the core, and in escaping: have
an injurious influence on the electric arc as respects its steady burning.
Now this invention has for, object to obviate these disadvantages for which
purpose: the carbon is provided with a thoroughly dense and firm core, whilst the
carbon proper is made of the finest graphite-containing carbon without impregna-
tion with the substances (formerly employed for the purpose of obtaining steady
burning.
For this purpose hollow rods, that is to say, rods formed with a core 'hole are
made by pressing, and are then baked, after which the substance. employed for the
core is charged into the core hole, a second baking being unnecessary.
•
The charging of the core is effected by any suitable means, such as a machine
constructed with an plunger capable of pressing or stamping the dry mixture of
finely pulverized carbon and the substance or substances used therewith to form the
desired core into the core hole, the form of the plunger in cross-section being such
that when moving downward.in.the core hole; air therein can escape easily and
quickly past tho plunger. For this purpose the plunger may conveniently be of
fluted or serrated form externally.
The choice of the dry substance or substances to be mixed with the finely
pulverized carbon will depend on the particular use for which the carbon rod-is.
intended:
Carbons produced in the manner described have an extremely firm and uniform
core.
The core hole is preferably of circular form in cross section, but may be
polygonal:
1
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
The hereinbefore described improvements in the manufacture of carbon rods for

page_text: electric aro lamps according to which the rods are each formed by pressure with a
core hole and then baked, after which a dry mixture of finely pulverized carbon
and other substance or substances to form the desired core is charged into the core
hole and formed by stamping into a dense and firm core whereby a second baking:
of the rod is rendered unnecessary as set forth.
Dated this 7th day of April 1892.
W. LLOYD WISE,
Per F. J. Brougham,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicant..