IMPROVEMENTS IN MACHINERY FOR CUTTING FILES
Year: 1865

page_text: PROVISIONAL SPECIFICATION left by George Tomlinson Bousfield at the
Office of the Commissioners of Patents, with his Petition, on the 8th:
December 1865.-A communication from abroad by Aaron Chambers,
residing at North Providence, in the County of Providence, and State of
Rhode Island, in the United States of America.
I, GEORGE TOMLINSON BOUSFIELD, of Loughborough Park, Brixton, in the
County of Surrey, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN MACHINERY FOR CUTTING FILES," to be as follows:-
This Invention has for its object improvements in machinery for cutting
files. In certain machines, which have been heretofore in use for cutting
files, the graver or cutting chisel used to cut the file is fixed in a carraige that.
has a reciprocating movement vertically to produce the repeated cuts upon the
file blank, and the file blanks to be cut are held in a kind of bed beneath
the graver or chisel, and this bed is made capable of moving in a number of
ways to present the surface of the file blanks of different kinds properly to the
graver or chisel for the same to be cut. These movements of the bed may be
mentioned as a rocking or tipping movement on trunnions at each side of the
bed near the middle of the same, by which the plane of the file blank on the bed
is set at an angle with the line of movement of the said graver or chisel to obtain
the requisite inclination of cut thereon; a swinging movement from side to
side on a central pin by which the angle of the cut across the face of the file
is obtained in either direction; a sliding movement endwise of the bed that is
graduated and intermittent for feeding the file blank beneath the graver or
chisel to produce the successive cuts; and a rolling or oscillating movement to
_
:

page_text: present the rounded surface of a half-round file (so called) so as to make the
successive rows of cuts thereon. Of the several movements above specified,
the rocking or tipping movement of the bed by which the file is placed at an
angle with the cutting chisel to obtain the proper cut or tooth, and the oscil-
lating or rolling movement of the bed by which the rounded surface of a file
is properly presented to the cutting chisel, are in some respects imperfect and
ineffectual for the full and complete performance of the work intended. The
imperfection, with reference to the rocking or tipping motion, being that no
provision is made for presenting at the proper angle the thinner tapering end
of the file blank to the cutter, so that the cuts may be formed at the same
relative inclination with this portion of the surface of the file blank, as the
same are formed on the remaining portion of the surface towards the shank
or tang, the result being that the cutter meets the file blank at a more obtuse
angle at or near the point of the file, and in consequence makes an in-
sufficient and imperfect tooth or cut. The imperfection, with reference to the
rolling or oscillating motion of the bed, is that no provision is made for the
variation of the contour or outline of the file's shape in cutting up to or
approaching the edges of a.half-round file or other rounded file surface,, so that
the tooth and cut shall be uniform and complete along the entire edge, and on
the surface of the file approaching the edges of the rounded surface. And
the object of the Invention in this case is to so qualify and control the said
rocking or tipping movement and the rolling or oscillating movements as to
place the file blank in the requisite position with respect to the cutting chisel
as the cutting proceeds, as the nature of the surface which is being cut shall
require to form a uniform and complete cutting toothed edge or surface, that
is to say:
The Invention consists in giving to the rocking or tipping bed above
mentioned a gradual tipping movement from the most acute angle with
respect to the cutting chisel which may be required to form the tooth properly
at the point of the file blank to the more obtuse angle at which the said bed
rests, and is held whilst the chisel is cutting over the belly and towards the
shank of the file, in order to form the teeth at the same relative angle with
the surface on the point and tapering portion of the blank, as upon the
remaining portion of the same. The means of obtaining such gradual tipping
of the bed may be varied, but it is conveniently accomplished by means of
cams or excentrics or templates acting on the bed progressively according to
the contour of the file blank placed on the bed.
And the Invention also consists in so controlling the rolling or oscillating
movement of the bed by means of self-adjusting mechanism for adjusting and

page_text: determining the position of the bed, as the cutting progresses, as to adapt the
cutting action of the chisel to the nature and general contour of file blank
which is being operated upon, and so produce the requisite depth and incli-
nation of cut uniformly on all parts of rounded surfaces of files, for which
purposes the file blank on the bed, or a pattern or template, thereof, or a cam
action is employed to govern or control the position of the bed, so that each
cut of the chisel or cutter is governed by the position of the part of the file
blank which is next to be cut.