Improvements in Pencils or Crayons.
Year: 1891

page_text: Date of Application, 26th May, 1891-Accepted, 18th July, 1891
COMPLETE SPECIFICATION.
[Communicated from abroad by AMERICAN LEAD PENCIL COMPANY, of 21 and
23, Mercer Street, and 50, Howard Street, New York City, New York,
United States of America.]
Improvements in Pencils or Crayons.
I, OLIVER IMRAY, of 28 Southampton Buildings, Chancery Lane in the County
of London, Fellow of the Institute of Patent Agents, 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 its object to provide new and useful flexible lead pencils,
slate pencils, and crayons, which are far stronger and tougher than any heretofore
made, and to such end it consists essentially, in a pencil or crayon composed of a
body-material such as plumbago or graphite or soapstone, or chalk, or china clay,
or blue or red or other coloring matter, in conjunction with a pyroxyline compound
and a non-volatile or essential oil.
In carrying my invention into effect, I mix by trituration or otherwise a quantity
of graphite or soapstone or plumbago and a quantity of nitro-cellulose or other
pyroxyline compound. The proportion of graphite or plumbago may vary from
fifty to one hundred and fifty (150) per cent. or more of the amount of pyroxyline
used according to the quality of pencil desired; or, instead of, plumbago, ivory or
lamp black or other dark pigment may be employed and the proportions of the
same may vary according to the intensity of the pigment used." To still further
intensify the color of the pencil, may be used, in addition to the pigment colors,
aniline colors such as nigrosine or the like.
In order to exemplify the working of the invention, I mix about as follows:-
To 100 parts in weight of dry pyroxyline pulp, I add 125 parts of graphite
75 parts camphor, and about 75 parts of alcohol.
This mixture is then manipulated on rolls as is well known in the arts, and then
pressed into blocks and cut into sheets, which are subdivided as may be desired,
or the rolled material may be placed into a stuffing machine and the material stuffed
into such shape as it may be needed. I have found that the above gives a pencil
of a good average marking quality.
In order to produce a pencil of a greater intensity of color, I increase the
proportion of graphite and add thereto a certain amount of lamp black or other
coloring matter. In this way I produce a very tough pencil which is totally free
from grit.
may use
I further have found that the mark of the pencil may be made more permanent
by an addition of oil to the aforesaid compound and for this purpose
castor or camphor or cedar oil, or other oil or glycerine, or stearine may be
employed. For example, 20 per cent. of cedar oil added to the ingredients afore-
said will make a pencil of excellent quality. Colored pigments may be employed
to produce various colored crayons or pencils in combination with pyroxyline, and
manipulated in the same manner as the before mentioned graphite compound.
The material, prepared as described, is formed into pencil sticks which may be
enclosed in wooden, paper or other sheaths, or the sticks can be used in holders
such as are adapted for ordinary movable leads or crayons.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
:-
1. A pencil or crayon consisting of an abrading body material, and a pyroxyline
compound, substantially as described.

page_text: 2. A pencil or crayon consisting of an abrading body material, a pyroxyline
compound and an oil or other substance, substantially as described.
3. A pencil or crayon consisting of an abrading body material, a pyroxyline
compound, and a coloring matter, substantially as described.
4. A pencil or crayon consisting of an abrading body material, a pyroxyline
compound, an oil and a coloring matter, substantially as described.
Dated this 26th day of May 1891.
ABEL & IMRAY,
Agents for the Applicant.