Improvements in the Manufacture of Writing Pencils.
Year: 1893

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COMPLETE SPECIFICATION.
Improvements in the Manufacture of Writing Pencils.
A communication by the Firm of MAHLA & BRAUN, of No. 8, Aussere Sulzbacher-
strasse, Nuremberg, in the Empire of Germany, Manufacturers.
I, WILLIAM PHILLIPS THOMPSON, F.C.S., M.I.M.E., of the Agency for
Foreign Patent Solicitors, 6, Lord Street, Liverpool, and 6, Bank Street,
Manchester, both in the County of Lancaster, and 323, High Holborn, in, the
County of Middlesex, Civil Engineer, 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:-
Wood covered pencils have hitherto been constructed by inserting the bar or
stick or supply of lead, coloured chalk, slate, or the like in one half of the casing,
which has been previously suitably grooved, and then gluing the other half of the
casing thereon.
The casing therefore consists of two parts in pencils constructed in this manner.
The method of making cased pencils which has been hereinbefore briefly
described is in practice both somewhat inconvenient and expensive.
Further, unless very great care be exercised in the manufacture of the pencils,
the drawback becomes apparent in this method of manufacture that the lead or
other insertion is not entirely enclosed by the casing, or connected with the same;
the result of this is that breakages (splintering) and so called slipping of the
insertion frequently take place.
By this invention, the insertion (lead) is held in a casing made in one piece, which
is formed by, pressure from a plastic mass and which serves as a substitute for the
wood' casing.
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In making this kind of pencils two courses may be adopted.
According to one method, the lead or other .bar which-is-employed as the
insertion may have the plastic mass directly pressed round it, and in this manner
a cased pencil may be produced, or by another method hollow tubes may be pressed
out of the substance of the shape of the cases, and the leads may be then inserted
therein.
In the first case, the separate leads are conveyed by means of a tube to the head
of a press, which is connected with a press containing a ductile or plastic substance
of suitable composition. On emerging from the above named tube, the leads are
then encased by the material emerging from the press cylinder under high pressure
(preferably hydraulic) and are carried away with this material. The material is
forced through an outer mouthpiece of preferably circular section and passes out of
the press in the form of a rod encasing one of the bars of lead, coloured chalk,
5 etcetera, which form the insertion. The rods or sticks formed in this manner are
cut off in suitable lengths, dried, and, if desired, polished or varnished and are then
ready for use.
By the above described method of coating or encasing, in consequence of the
high pressure exerted, an absolutely firm thorough connection of the insertion with
0 the casing along its entire length is obtained and that naturally without the use of
glue or other like adhesive substance, and thus the above named breakage or
slipping of the insertions is prevented.
In the second method mentioned, the improved process is modified by a spike of
the thickness of the insertion being inserted in the outer mouthpiece of the press
5 head in place of the supply tube and the mass being then forced through this
mouthpiece in the form of an endless tube.
The tubes produced in this manner are cut into pieces of a suitable length, and
the leads are inserted in the hollow parts of the same as long as the tubes remain

page_text: moist. By the contraction of the material which takes place on drying, the
inserted lead is tightly enclosed along its entire length and is consequently
thoroughly and reliably secured in its casing. The further treatment of the
pencils or rods formed in this way is the same as in the previous case. For forming
the case in one piece which is pressed on or hollow moulded, a substance is employed
which, when pressed and dried, that is to say when in a completed condition, equally
exhibits the most advantageous properties of wood for this object, and more
particularly the capability of allowing the pencil to be easily sharpened. Such
substances for instance are artificial wood (powdered wood mixed with some
suitable adhesive substance) celluloid, cellulose and like, suitably prepared.
Pencils of any desired shape, circular, angular, ribbed, etcetera, may be produced
in the manner hereinbefore described by making use of mouthpieces of suitable
section.
In addition to the already stated advantages as regards the improved connection
between lead and casing, this improved process excels all the methods of manufacture
hitherto employed from the circumstance that, owing to all intermediate work being
dispensed with, the cost of production of the pencils is very considerably reduced,
and in this direction also this improved process constitutes an important technical
advance in the manufacture of writing pencils.
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-
A process for making cased writing pencils with a casing in one piece
characterised by the bars of lead or the like, which form the insertion of the
above named pencils, being either directly encased with a plastic mass, or inserted
in tubes formed by pressure from such substance, and secured therein by the shrinkage
which takes place on the substance drying.
Dated this 31st day of October 1893.
WM. P. THOMPSON & Co.,
Agents for the Applicant.