IMPROVEMENTS IN THE MANUFACTURE OF CARBONS' TO BE EMPLOYED FOR THE PRODUCTION OF ELECTRIC LIGHT
Year: 1881

page_text: LETTERS PATENT to Charles James Allport, of 161, Queen Victoria Street, in
the City of London, E.C., and Robert Punshon, of 16, Saint Michael's Place,
Brighton, in the County of Sussex, for an Invention of "IMPROVEMENTS IN
THE MANUFACTURE OF CARBONS' TO BE EMPLOYED FOR THE PRODUCTION
OF ELECTRIC LIGHT."
PROVISIONAL SPECIFICATION left by the said Charles James Allport and
Robert Punshon at the Office of the Commissioners of Patents on the 5th
November 1881.
CHARLES JAMES ALLPORT, of 161, Queen Victoria Street, in the City of London,
E.C., and ROBERT PUNSHON, of 16, Saint Michael's Place, Brighton, in the County
of Sussex. "IMPROVEMENTS IN THE MANUFACTURE OF 'CARBONS' TO BE
EMPLOYED FOR THE PRODUCTION OF ELECTRIC LIGHT."
The object of our Invention is to produce an improved form of carbon suitable
for incandescent electric lamps, made by a film or covering of carbon on an asbestos
cord or thread. Our method of making the carbon is to take a thread or cord of
fibrous asbestos and soak it in a saturated solution of pure sugar, by preference a
saturated solution made from the crystals of pure cane-sugar, and then thoroughly
dry the asbestos thread or cord so as to deposit a film or coating of pure sugar
upon it. This process of soaking may be continued till a film or coating of sugar
is deposited on the asbestos thread or cord of the thickness required. When dry,
we dip the sugar-coated asbestos thread or cord in naptha, benzole, or other
suitable hydro-carbon, and immediately set it on fire, thereby carbonizing the
sugar, and this process may be repeated if necessary until the film or coating of
sugar is completely converted into pure carbon; or the film or coating of sugar may
be carbonized in any other suitable manner. This Invention will produce a
resistance necessary for the production of an incandescent electric light, and may
be used in any form of incandescent electric lamp.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Charles James Allport and Robert Punshon in the Great Seal
Patent Office on the 5th May 1882.
CHARLES JAMES ALLPORT, of 161, Queen Victoria Street, in the City of London,
E.C., and ROBERT PUNSHON, of 16, St. Michael's Place, Brighton, in the County of
Sussex. "IMPROVEMENTS IN THE MANUFACTURE OF CARBONS TO BE EMPLOYED
FOR THE PRODUCTION OF ELECTRIC LIGHT."
The object of our Invention is to produce an improved carbon or loop for electric
lamps, and mainly incandescent lamps.
The Invention consists in the manufacture of the said carbon or loop by
depositing or securing on an asbestos cord or thread a film, covering, or coating of
carbon.
In carrying our Invention into practice we immerse, dip, or soak a cord or
thread of asbestos in a saturated solution of crystalizable sugar-cane, sugar being
preferred, or in melted or liquid sugar, or in inverted or uncrystalizable sugar,
such as treacle. The sugar filin covering or coating on the cord or thread of
-asbestos_is_then_carbonized by dipping the coated cord or thread into liquid
naptha, benzole, or other suitable hydrocarbon,-and-thereafter_setting fire to the
dipped carbon or loop, or by being subjected to the action of flames or heated
gases, or other suitable means.
In order to obtain a sufficiently thick film covering or coating of carbon on the
asbestos cord or thread, the said cord or thread is several times dipped, soaked, or
immersed in liquified sugar, and the said film, covering, or coating is dried or
carbonized after each immersion, or is carbonized after a sufficient deposit has been
obtained by repeated immersions.
The cord or thread forming the base of the carbon or loop is preferably bent into
the desired form before carbonization. Pressure in dies or otherwise may be used
to consolidate and harden the coating or film.
When asbestos is used in carbons for the are light it must be so disposed that it
will serve as a binding agent and aid in preserving large pieces from breaking off.
Having now described and particularized our said Invention in such manner
that others will be able to carry our improvements into effect, we claim,-
Carbons or loops for incandescent lamps of fibrous asbestos coated with carbon,
substantially as herein set forth.
In witness whereof, we, the said Charles James Allport and Robert Punshon,
have hereunto set our hands and seals, this Fifth day of May, in the year
of our Lord One thousand eight hundred and eighty two.
CHARLES J. ALLPORT. (L.S.)
ROBERT PUNSHON.
(L,S.)