RELATING TO HEADS FOR LEAD PENCILS, INK ERASERS, AND OTHER ARTICLES OF LIKE. CHARACTER
Year: 1861

page_text: LETTERS PATENT to Levi Lincoln Tower, of the State of Massachusetts,
of the United States of America, for the Invention "RELATING TO
HEADS FOR LEAD PENCILS, INK ERASERS, AND OTHER ARTICLES OF LIKE.
CHARACTER." A communication from Francis Pickard Hale, Jr., residing
in Boston, of the State aforesaid.
COMPLETE SPECIFICATION filed by the said Levi Lincoln Tower at the
Office of the Commissioners of Patents, with his Petition and Declaration,.
on the 20th March 1861, pursuant to the 9th Section of the Patent Law.
Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, BE IT.
KNOWN, that I, LEVI LINCOLN TOWER, of the State of Massachusetts, of the
United States of America, am in possession of an Invention "RELATING
TO HEADS FOR LEAD PENCILS, INK ERASERS, AND OTHER ARTICLES OF LIKE
CHARACTER," communicated to me by Francis Pickard Hale, jun'., a person
resident in Boston, of the State aforesaid, and I do hereby declare that the
nature of the said Invention; and the manner in which the same is to be
performed, are fully described in the following Specification and illustrated
in the accompanying Drawings, of which Figure 1 denotes a central and
longitudinal section of one of one of my improved heads. Figure 2 exhibits a
central and longitudinal section of the head as slightly modified in form.

page_text: Figures 3 and 4 are side elevations of pencils having one of such heads applied
to them. Figures 5 and 6 represent central and vertical sections of the moulds
used for forming the heads of the shapes shown in the Drawings. Figures 7,
8, and 9 respectively represent vertical sections of the three parts of the mould
as detached.
The nature of the said Invention consists, first, in an improved head
composed of india-rubber or india-rubber and powdered emery, such head to
be applied to a lead pencil or other article of like character, for the purpose
of enabling a person to erase from paper any pencil or other erasable mark
be may desire to remove from such paper. It further consists in an improve-
ment in moulds for forming. such heads.
In carrying out the said Invention for the production of a head for érasing
pencil marks, I cut, by means of a die from a strip or block of india-rubber,
a piece of suitable size to form the head; such piece is next put into the
mould, next the mould with the rubber is subjected for a few moments to
the action of both heat and pressure (in a press heated either with steam
or any other suitable means), which gives the head its desired form. Should
I desire to produce a head for erasing ink marks from paper, I add to
90 parts of the rubber about 10 parts by weight of powdered emery or its
equivalent, and then mould the head as before described.
The mould O is composed of three plates of metal o, p, q; o being the
cap plate; p, the middle plate; and 2, the core plate; the plates being confined
together by means of studs s, s, extending from the upper and lower plate
into corresponding holes made in the middle one, as seen in the Drawings.
I usually make the head of the form as shown in Figure 1, as such form
not only gives the pencil or article to which it is attached a neater appearance,
but is very convenient, as it can be used on all sides with equal effect, and
when properly constructed will last a long time without being used up. The
head shown in Figure 2, although not so pleasing in form as that shown in
Figure 1, is of great advantage to the draughtsman, as it enables him by
reason of its pointed end to reach a single point or remove a line from his.
drawing without erasing other lines or marks in the immediate vicinity of
the erasure to be made. The head A has a socket formed in its lower end,
such socket extending axially about two-thirds the length of the head, as
seen in the Drawings, the diameter of such socket being about one-half of
the diameter of the lower end of the head which is intended to be very
nearly the diameter of a common lead pencil, such as Faber's for instance.
In applying my, improved head to a lead pencil, I usually chamfer down
one end of the pencil (in manner as shown in the Drawing) to a diameter

page_text: a little greater than the diameter of the socket, leaving the upper part of the
chamfered portion slightly larger in transverse section than the lower part,
in order to hold such head more firmly to the pencil when it may be drawn
upon it. A head made and applied to a pencil as above explained and
represented in the Drawings constitutes an article of great practical utility
and value to accountants, draughtsmen, and others having occasion to use a
pencil.
I claim the above-described improved manufacture or head A; as composed
of either caoutchouc alone or caoutchouc and powdered emery (or its
equivalent) combined, the said head to be applied to a lead pencil or other
article of like character, substantially as shown, and for the purpose set
forth.
I also claim the above-described improvement in moulds for moulding such
heads.
In witness whereof, I have hereunto set my hand and seal, this 1st day
of March 1861.
LEVI LINCOLN TOWER. (L.S.)