IMPROVEMENTS IN RASPS
Year: 1868

page_text: LETTERS PATENT to Stillman Boyd Allen, of Boston; of the State
of Massachusetts, of the United States of America, for the Inven-
tion of "IMPROVEMENTS IN RASPS." -A communication by Hiram
Nickerson, residing at Boston, in the State of Massachusetts.
Sealed the 17th October 1868, and dated the 18th May 1868.
PROVISIONAL SPECIFICATION left by the said Stillman Boyd Allen
at the Office of the Commissioners of Patents, with his Petition,.
on the 13th May 1868.
I, STILLMAN BOYD ALLEN, of Boston, of the State of Massachusetts,.
5 of the United States of America, do hereby declare the nature of the
said Invention for "AN IMPROVEMENT IN RASPS," to be as follows:-
Figures 1 and 3 of the accompanying Drawings exhibit the arrange--
ment of the rasp teeth constituting the Invention or improvement ;-
Figure 2 exhibits the common arrangement of such teeth..

page_text: The nature of the said Invention consists in a peculiar arrangement
of the teeth of the rasp whereby it is made to operate to much better
advantage than when made with teeth arranged in the usual manner
heretofore adopted and exhibited in the said Figure 2. In the ordinary
way of cutting the teeth of a rasp the tool or cutter is held at an
acute angle with the surface on which the tooth is to be raised, and it
is ranged in a direction lengthwise of the rasp so as to make the cut
in that direction, in which case the cutting front face of a tooth
usually stands at or very nearly at right angles with the opposite edges
of the blank.
rasp
In carrying out the improvements the teeth of each range are to
be cut so that their fronts or cutting faces shall be oblique or at acute
angles with the edges of the rasp, those of one range being made to
stand obliquely in one direction while those of the next range are made
to stand obliquely in the opposite direction, as shown in Figure 1. The
angles of obliquity of the cutting faces of the teeth I prefer to have
forty-five degrees or thereabouts with the edges of the rasp, the same
being as shown in Figure 1, in which the teeth of one range are repre-
sented at a, a, and those of the next range at b, b. The edges of the
rasp are shown at c, c.
With the improved or oblique arrangement of each tooth it is caused
when in use to cut with a drawing stroke, and to operate so much
better than the square tooth, or that arranged as shown in Figure 2
(viz., at right angles to the edges of the rasp) that a rasp made in
the improved manner will cut through a bar of wood in about one-
third the time that would be required to accomplish the same with
a square tooth rasp. An experiment made with one of the improved
rasps and another of the ordinary kind of the size demonstrated that
it required but thirty-seven movements of the improved rasp to ninety-
two of the common rasp to effect like cuts through a bar of wood.
The improved rasp works much more casily than the common rasp and
in other respects to better advantage. Its teeth do not choke but
readily clear themselves of the wood or raspings.
I claim a rasp having the teeth of each range of teeth disposed
obliquely to the edges of the rasp, and so that the cutting face of each
tooth shall have its obliquity arranged in a direction opposite to or

page_text: about at right angles with or obliquely to that of each of the teeth of
the next adjacent range, the whole being substantially as exhibited in
Figure 1 and as herein-before described.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Stillman Boyd Allen in the Great Seal Patent
Office on the 12th November 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, STILLMAN
BOYD ALLEN, of Boston, of the State of Massachusetts, of the United
States of America, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Thirteenth day of May, in the year of
our Lord One thousand eight hundred and sixty-eight, in the thirty-first
year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto me, the said Stillman Boyd Allen, Her special licence that
I, the said Stillman Boyd Allen, my executors, administrators, and
assigns, or such others as I, the said Stillman Boyd Allen, my executors,
administrators, and assigns, should at any time agree with, and no
others, from time to time and at all times thereafter during the term
therein expressed, should and lawfully might make, use, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "AN IMPROVEMENT IN
RASPS," (a communication), upon the condition (amongst others) that I,
tho said Stillman Boyd Allen, my executors or administrators, by an
instrument in writing under my, or their, or one of their hands and
seals, should particularly describe and ascertain the nature of the said
Invention, and in what manner the same was to be performed, and
cause the same to be filed in the Great Seal Patent Office within six
calendar months next immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said Stillman Boyd Allen, do hereby
declare the nature of the said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained in
and by the following statement, and represented in Figures 1 and 3 of
the accompanying Drawings, which exhibit the arrangement of the

page_text: rasp teeth constituting my Invention or improvement; Fig. 2 exhibits
the common arrangement of such teeth.
In the ordinary way of cutting the teeth of a rasp the tool or cutter
is held at an acute angle with the surface on which the tooth is to be
raised, and it is ranged in a direction lengthwise of the rasp so as to
make the cut in that direction, in which case the cutting front face
of a tooth usually stands at or very nearly at right angles with the
opposite edges of the rasp blank.
In carrying out my improvement the teeth of each range are to be
cut so that their fronts or cutting faces shall be oblique or at acute
angles with the edge of the rasp, those of one range being made to
stand obliquely in one direction, while those of the next range are
made to stand obliquely in the opposite direction, as shown in Fig. 1.
The angles of obliquity of the cutting faces of the teeth I prefer to
have forty-five degrees or thereabouts with the edges of the rasp, the
same being as shown in Fig. 1, in which the teeth of one range are
represented at a, a, and those of the next range at b, b. The edges
of the rasp are shown at c, c.
With my improved or oblique arrangement of each tooth it is caused
when in use to cut with a drawing stroke and to operate so much
better than the square tooth or that arranged as shown in Fig. 2 (viz.,
at right angles to the edges of the rasp) that a rasp made in my
improved manner will cut through a bar of wood in about one-third the
time that would be required to accomplish the same with a square
tooth rasp.
An experiment made with one of my improved rasps
and another of the ordinary kind of the size demonstrated that it
required but thirty-seven movements of my rasp to ninety-two of the
common rasp to effect like cuts through a bar of wood. My improved
rasp works much more easily than the common rasp, and in other
respects to better advantage. Its teeth do not choke but readily clear
themselves of the wood or raspings.
This Invention consists of an improved rasp or an arrangement of
the teeth thereof, whereby the teeth of each range are disposed
obliquely to the edges of the rasp, so that the cutting face of each
tooth shall have its obliquity arranged in a direction opposite to or
at about right angles with or obliquely to that of each of the teethi
of the next adjacent range; and I claim as my Invention a rasp formed

page_text: substantially in the manner herein set forth and illustrated in Figures
1 and 3 of the accompanying Sheet of Drawings.
In witness whereof, I, the said Stillman Boyd Allen, have here-
unto set my hand and scal, this Seventeenth day of August,
in the year of our Lord One thousand eight hundred and sixty-