An Improved Manufacture of Writing Pencils.
Year: 1893

page_text: Date of Application, 18th Dec., 1893
Complete Specification Left, 10th Sept., 1894-Accepted, 13th Oct., 1894
PROVISIONAL SPECIFICATION.
[Communicated from abroad by ADAM CHARLES GIRARD and ERNEST AUGUSTE
GEORGES STREET, both of 12 and 33, Rue de Lorraine, Levallois-Perret,
near Paris, in the Republic of France.]
An Improved Manufacture of Writing Pencils.
I, HENRY HARRIS LAKE, of the Firm of Haseltine Lake & Co., Patent
Agents, 45 Southampton Buildings, in the County of Middlesex, do hereby declare
the nature of this invention to be as follows:-
Our invention relates to an improved manufacture of writing pencils and has
for its object the production of writing pencils or crayons from carbon.
We take powdered carbon of any variety, for example lamp-black, or retort
carbon, and transform the same into graphite of varying degrees of hardness by
submitting it to temperatures reaching approximately to those at which carbon
softens, welds, melts or volatilizes.
The carbon can be transformed into graphite either before or after being formed
into the shape which the pencil or crayon is to have when finished. When we
desire to transform the carbon before it has been moulded or shaped into definite
form, we submit it in a powdered condition to the temperatures indicated
above, that is to say, temperatures at which carbon welds, softens, melts or
volatilizes. Under this treatment the powdered carbon changes its nature and
properties, and is transformed into graphite having all the characteristics of
plumbago or powdered natural graphite.
In carrying our invention into practice we may employ for obtaining the
requisite temperature, the electric furnace which is described in the Provisional
Specification No. 13340 filed 8th July 1893. In this furnace the heat is produced
through the agency of two electric arcs in series or by the aid of several groups
of two such arcs in series and if carbon powder is used it is passed through a carbon
tube which preferably serves as an electrode common to all the electric arcs.
is obvious that other forms of carbon may be used, carbon powder being adopted as
an example.
It
The artificial graphite thus obtained is mixed with precipitated chalk or other
suitable material in proportions which vary with the hardness it is desired to secure
in the finished pencils. We now moisten the mass with linseed oil or other suitable
agglutinant and then mould or draw the resulting paste through a draw-plate so
as to form it to the shape we wish the pencils or the crayons to possess. Or the
form may be obtained by pressing or moulding.
These leads may then be placed in the ordinary wooden sheaths if required.
Another mode of operation which we may employ for the production of pencils
or crayons of artificial graphite is as follows, that is to say, we mix the carbon in
a more or less powdered state with a suitable agglutinant such as tar, and we
mould or draw the paste thus formed through a draw plate to obtain the desired
shape in the finished pencil.
The rods or sticks thus made are baked in suitable chambers or ovens to distil,
or free them from, the greater part or the whole of the hydrocarbons or other
materials contained in the agglutinant. We obtain in this manner rods.or sticks
which consist of what we will call metallic carbon to distinguish it from
amorphous or graphitic carbon.

page_text: In order to transform these rods or sticks from the aforesaid metallic carbon
state to the graphitic carbon state it is necessary to subject them to the herein-
before mentioned very high temperatures, which may be done in the electric
furnace described in the Provisional Specification hereinbefore referred to, or
otherwise. In this furnace the rods or sticks are subjected to the heat produced
from an electric arc or arcs and are thereby raised to such temperatures that they
are wholly or partially transformed into graphite.
The transformation is more or less complete according to the length of time
during which the carbon is subjected to the action of the heat produced from an
electric arc or arcs and according to the intensity of the electric current which is
passed through the apparatus.
We can by this means obtain pencils or crayons which are of any desired degree
of hardness. Thus for example with a rod of metallic carbon 8 millimetres in
diameter a current of 25 amperes gives an- extremely hard crayon or pencil, a
current of 50 amperes gives a softer crayon, and a current of 100 amperes an
extremely soft crayon. The only limit to the degree of softness is the degree of
solidity which is required in practice for the crayon or pencil. The leads or crayons
thus obtained can be supplied as such or they may be placed in wooden sheaths
according to the usual practice with ordinary leads.
When we supply the leads without wooden or other sheaths we may according
to our invention cover such leads or crayons with a metallic deposit of copper,
nickel or the like by electrolysis or other suitable method, so as to avoid soiling
the fingers or other surfaces with which they may come in contact. We sometimes
with the same object in view coat the said lead or crayons, with varnish, enamel
or the like, or with a suitable oil in which case we subsequently rub and polish
them. The light, greasy film which remains on the crayon after such treatment
prevents to a certain extent the blackening of the fingers or other surfaces.
Dated this 18th day of December 1893.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.
.
COMPLETE SPECIFICATION.
An Improved Manufacture of Writing Pencils.
I, HENRY HARRIS LAKE, of the Firm of Haseltine, Lake & Co., Patent Agents,
45 Southampton Buildings, in the County of Middlesex, 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 relates to an improved manufacture of writing pencils and has
for its object the production of writing pencils or crayons from carbon.
I take powdered carbon of any variety, for example lamp-black, or retort carbon,
and transform the same into graphite of varying degrees of hardness by submitting
it to temperatures reaching approximately to those at which carbon softens, welds,
melts or volatilizes.
The carbon can be transformed into graphite either before or after being formed
into the shape which the pencil or crayon is to have when finished. When I desire
to transform the carbon before it has been moulded or shaped into definite form,
I submit it in a powdered condition to the temperatures indicated above, that is to
say, temperatures at which carbon welds, softens, melts or volatilizes. Under this
treatment the powdered carbon changes its nature and properties, and is transformed
into graphite having all the characteristics of plumbago or powdered natural
graphite.
In carrying my invention into practice I, according to one method, employ for
obtaining the requisite temperature, the electric furnace which is described in the

page_text: Specification of prior Letters Patent No. 133 40 dated 8th July 1893. In this
furnace the heat is produced through the agency of two electric arcs in series, or
by the aid of several groups of two such arcs in series, and if carbon powder is
used it is passed through a carbon tube which preferably serves as an electrode
common to all the electric arcs. It is obvious that other forms of carbon may be
used, carbon powder being adopted as an example.
The artificial graphite thus obtained is mixed with precipitated chalk or other
suitable material in proportions which vary with the hardness it is desired to secure
in the finished pencils. I now moisten the mass with linseed oil or other suitable
agglutinant and then mould or draw the resulting paste through a draw-plate so as
to form it to the shape I wish the pencils or the crayons to possess. Or the form
may be obtained by pressing or moulding.
These leads may then be placed in the ordinary wooden sheaths if required.
Another mode of operation which I sometimes employ for the production of
pencils or crayons of artificial graphite is as follows, that is to say, I mix the
carbon in a more or less powdered state with a suitable agglutinant such as tar,
and I mould or draw the paste thus formed through a draw plate to obtain the
desired shape in the finished pencil.
The rods or sticks thus made are baked in suitable chambers or ovens to distil,
or free them from, the greater part or the whole of the hydrocarbons or other
materials contained in the agglutinant. I obtain in this manner rods or sticks
which consist of what I will call metallic carbon to distinguish it from amorphous
or graphitic carbon.
In order to transform these rods or sticks from the aforesaid metallic carbon
state to the graphitic carbon state it is necessary to subject them to the herein before
mentioned very high temperatures, which may be done in the electric furnace
described in the Specification hereinbefore referred to, or otherwise. In this
furnace the rods or sticks are subjected to the heat produced from an electric arc
or arcs and are thereby raised to such temperatures that they are wholly or partially
transformed into graphite.
The transforniation is more or less complete according to the length of time
during which the carbon is subjected to the action of the heat produced from an
electric arc or arcs and according to the intensity of the electric current which is
passed through the apparatus.
I can by this means obtain pencils or crayons which are of any desired degree
of hardness. Thus for example with a rod of metallic carbon 8 millimetres in
diameter a current of 25 amperes gives an extremely hard crayon or pencil, a
current of 50 amperes gives a softer crayon, and a current of 100 amperes an
extremely soft crayon. The only limit to the degree of softness is the degree of
solidity which is required in practice for the crayon or pencil. The leads or
crayons thus obtained can be supplied as such or they may be placed in wooden
sheaths according to the usual practice with ordinary leads.
I
When I supply the leads without wooden or other sheaths I may according to
this invention cover such leads or crayons with a metallic deposit of copper, nickel
or the like by electrolysis or other suitable method, so as to avoid soiling the
fingers or the paper or other surfaces with which they may come in contact.
sometimes with the same object in view coat the said lead or crayons, with varnish,
enamel or the like, or with a suitable oil, in which case I subsequently rub aal
polish them. The light, greasy filin which remains on the pencil or crayon after
such treatment prevents to a certain extent the blackening of the fingers or paper
or other surfaces when the pencil or crayon is in use.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, as communicated to me by
my foreign correspondents, I declare that what I claim is :-
1. The method herein described of manufacturing writing pencils or crayon,
which consists in heating carbon by means of an electric furnace or otherwise to

page_text: the temperature herein indicated to convert the same into graphite, then mixing
with the graphite a suitable agglutinant, and subsequently drawing, pressing, or
otherwise forming the same to the shape which the pencil is to have when finished.
2. In the manufacture of writing pencils or crayons, mixing, with the artificial
graphite produced as herein described, powdered chalk, or other suitable substance,
prior to adding the agglutinant, for the purpose specified.
3. The modified process or method of manufacture herein described which
consists in mixing tar or other suitable agglutinant with the carbon, and then
moulding drawing or otherwise shaping the pencils from such mixture and baking
the same and then transforming the carbon into graphite.
4. In the manufacture of writing pencils and crayons, protecting the surface of
the pencils by a copper or other inetallic coating deposited by electrolysis or
otherwise, substantially as described.
5. In the manufacture of writing pencils, and crayons, protecting the surface of
the pencils by varnish enamel or the like, or with a suitable oil which latter is
rubbed in and the surface then polished, substantially as described.
6. Writing pencils manufactured according to the methods or processes herein
described.
Dated this 10th d... S
1004
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.