IMPROVEMENTS IN MACHINERY FOR CUTTING FILES
Year: 1850

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
EDWARD NEWTON, of the Office for Patents, 66, Chancery Lanc, in the County
of Middlesex, Civil Engineer, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Twenty-third day of July, in the fourteenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said William Edward Newton, Her especial license, full power, sole privilege
and authority, that I, the said William Edward Newton, my exors, admors
and assigns, and such others as I, the said William Edward Newton, my exors,
adiñors, or assigns, should at any time agree with, and no others, from time.
to time and at all times during the term of years therein mentioned, should
and lawfully might make, use, 'exercise, and vend, within England, Wales.
and the Town of Berwick-upon-Tweed, and in all Her Majesty's Colonies
and Plantations abroad, and in the Islands of Jersey, Guernsey, Alderney;
Sark, and Man, an Invention of "IMPROVEMENTS IN MACHINERY FOR CUTTING
FILES," being a communication from abroad; in which said Letters Patent is
contained a proviso, obliging me, the said William Edward Newton, by an
instrument in writing under my hand and seal, particularly to describe and
ascertain the nature of the said Invention, and in what manner the same
is to be performed, and to cause the same to be enrolled in Her Majesty's
High Court of Chancery within six calendar months next and immediately

page_text: after the date of the said in part recited Letters Patent, as in and by the same,
reference being thereunto had, will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
William Edward Newton, do hereby declare that the nature of the said
Invention, and the manner in which the same is to be performed, is particu-
larly described and ascertained in and by the following description thereof,
reference being bad to the Drawings hereunto annexed, and to the letters and
figures marked thereon (that is to say) :—
This Invention of improvements in machinery for cutting files is thus
described by my foreign correspondent, reference being had to the accom-
panying Drawings, making part of this Specification. Fig. 1 is a side clevation
of a machine constructed according to these improvements; Fig. 2 is a front
clevation; Fig. 8, a horizontal section taken at the line A, a, of Fig. 1; Fig. 4,
a vertical section taken at the linc B, 6, of Fig. 3; Fig. 5, a rear end view of
the carriage with the file holder; Fig. 6, a cross section of the carriage; Fig. 7,
a vertical section of the feed motion; Fig. 8, a longitudinal and vertical section
of the file bed for cutting the edges of files; Fig. 9, a cross section of the same;
and Figs. 10, a longitudinal and cross section of a modification of the carriage.
The same letters indicate like parts in all the Figures. Files are usually made
of a form presenting four faces, which are more or less curved, and slightly
swelling from the handle towards the middle, and decreasing in a more sudden
curve towards the point. These curves, as the file passes under the cutter,
necessarily vary the range of its motion in cutting, the motion being greatest
where the file is thinnest and narrowest, so that the force of the blow is greatest
where it should be the least, hence the teeth will be cut deeper towards the
point than at or towards the middle. Again, the two ranges of teeth cross
each other at given angles to the axis of the file, and the motion of the cutter
must be diagonal to the general plane of the face of the file to make the
teeth pointing towards the nip or point of the file. These peculiarities in the
form of the body and the teeth present serious practical difficulties. If the
cutting edge be made as it should be, (viz.,) at right angles to the plane of its
motion, it will be in the right position to cut one range of teeth; when the
cutting edge is reversed, it will then, by reason of its obliquity, be oblique to
the face of the file and only touch it at one edge, hence such an arrangement
is impracticable. If the cutting edge be made diagonal to the plane of its
motion, and reversed for the second range of teeth, then the plane of motion
of the cutter will be diagonal, and the force of the blow will be greatest on one
side in cutting one range of teeth, and greatest on the other in cutting tho
other range, the result of which must necessarily be an imperfect file. And,

page_text: finally, the curve of the face and the line of the ranges of teeth being diagonal
to the axes of the file, slightly varies the relations of the cutting edge to the
plane of the face to be cut as the file moves under the cutter from the face to
the handle, and from this it must follow that if the edge of the cutter and the
face of the file be not made to shift as the file passes under the cutter, the cuts
will vary, and the teeth produced be uneven.
The above practical difficulties will be in part or wholly obviated by the
present improvements, which consist, first, in shifting the line of motion of the
feeding carriage or the plane of the file to be cut for the cutting of the second
range of teeth on each face, so that while the cutter retains the same position,.
the feeding motion of the carriage in cutting the first range of teeth shall be
in a line diagonal to the face of the cutter, and in cutting the second range of
teeth the said motion shall be in a line the reverse of the angle of the first,
whereby the power applied for cutting the teeth will exert an equal force over
the entire breadth of the file; second, in connecting the cutter or chisel, or
the stock thereof, with the slide, by which the power for cutting the teeth is.
applied by means of a joint, the axis of which shall be at right angles, or
nearly so, with the face of the cutter, whereby the cutting edge is rendered
self-adapting to the slight variations of the face of the file as it passes under
the operation of the cutter, by reason of the curved face of the file and the
diagonal lines of the teeth, and also to any slight inequality in the texture of
the metal to be cut; and, third, in regulating the force of the cut, according to
the surface of the metal to be cut, by increasing or diminishing the tension of
a spring or the leverage of a weight which acts on a slide to operate the cutter
by means of a plane on the carriage, so formed as to give the required variation.
to the force applied.
In the accompanying Drawings, a, a, represents the bed frame of the ma-
chine, to which is properly secured the upper framework b. The top of the
bed frame a is formed with two ways or guide rails c, c, on which runs a
carriage d, provided at one end with a rocking piece c, that slides vertically in
a recess in the carriage. This rocking piece has on its under side a semi-
circular groove, which is threaded to fit the threads of a feed screw f, hung in
journals between the two ways or rails c, c; and on the outer end of the shaft
of the screw fa ratchet wheel g is mounted, and is operated by a click or
pall h, connected by means of a stud or adjustable pin i to an arm j, mounted
on a rocking shaft k, as seen best in Fig. 2. This rocking shaft k has another
arm 1 (Fig. 3), to which is jointed the lower end of a vertical rod m, that slides.
in a tube n, surrounded by a helical spring o. All these parts are shewn more
clearly in the detached view, Fig. 7. The spring o rests at its lower end on a

page_text: collar, and at its upper end bears against a pin p, that projects from the rod m
and which slides in slots in the tube, so that the tension of the said spring
shall always tend to force up the rod, and thus draw back the click or p 11 h,
which at every revolution of the main shaft q is pushed forward to turn the
ratchet 9 the required distance, according to the length of leverage of the con-
nection of the pall with the arm of the rocking shaft. This motion is effected
by means of a cam r on the main shaft, as this cam r, by the rotation of the
main shaft, is made to act on the upper end of the rod m, properly formed for
that purpose. In this way, at each rotation of the main shaft, the carriage is
moved forward the distance required for the cutting of a tooth. At the end of
the feeding motion the carriage is moved back by the attendant, who for this
purpose must first disengage the block e, which is secured by a screw passing
through a slot to the middle of a short lever r¹, connected with a hand lever
which runs to the front end of the carriage so as to be within reach of the
attendant. The bed of the carriage is properly formed and lined with lead, to
receive the piece of metal to be cut or formed into a file, the heel or stem of
which is secured by passing it through a slot in a piece s, and there secured by
a temper screw, the said piece being free to turn by being mounted in journals
in two bracket pieces t, t, that project, as seen best in Fig. 3, from a plate 2,
connected with the end of the carriage by two screws v, v, that pass through
elongated holes, to admit of adjustment to the bed of the carriage. When
cutting the edges of files, the bed should be made as represented in Figs. &
and 9, with moveable pieces w, w, which can be shifted according to the form
and size of files to be cut, and thus form a solid and firm bed.
The cutter or chisel (Figs. 2 and 4) is formed with a stem, fitted and
secured by a temper screw y in the socket of the lower half of a stock z,
which is jointed to the upper half by a screw bolt a¹. The two halves of this
stock are put togother in the manner of the well-known rule joint, so that
the chisel or cutter shall have sufficient lateral play to adapt itself to the
varying plane of the surface of the file. The upper end of the stock is fitted
by a stem in a socket at the lower end of a heavy block of metal b', called a
slide, and is there secured by a temper screw c¹. The slide b¹ is a quadran-
gular prism of the requisite weight, and slides in two cross bars d', d', of
the frame, each of which are made in two parts, and are connected together
by screw bolts e, el, so that they may be adjusted to the slide. The position
of the slide is in a plane perpendicular to the transverse plane of the bed
frame, and inclines back from a line perpendicular to the longitudinal plane
of the bed frame, so as to give the inclined cut required to make the teeth of
the file sharp towards the point of the file. At about the middle of its length

page_text: the slide is provided with a strap f, which is properly secured to it, and
has two trunnions g¹, g', on opposite sides, which play in the slots of two
arms h', h, of a rocking shaft i, which has its bearings in the upper frame b,
and is provided with another arm, which at its outer end carries a roller k'.
This roller k is forced down by means of the cam on the main shaft and
by that means made to lift the slide with its cutter or chisel. The cam l^,
which operates the slide, has a greater sweep than the cam r, and begins to
lift the cutter before the cam r begins to operate the feed motion; but so soon
as the feed motion is completed the cam liberates the rocking shaft, and
thereby permits the slide and chisel to descend and cut a tooth on the blank
or file. As the rocking shaft is operated so as to lift the slide, a projecting
piece m (Fig. 4) is brought in contact with a spring n', attached to another
rocking shaft o¹, from which projects an arm p', provided with a set screw q',
the point of which comes in contact with and is arrested by an arm s¹, of
another rocking shaft t¹ (Fig. 4), which has another arm ', that carries a
roller v. This roller runs on a plane w', attached to and carried by the
carriage d, and after the arm p' of the rocking shaft o' has been arrested the
continned upward motion of the slide gives tension to the spring n³, and the
recoil thereof aids in forcing down the slide to make the cut, hence the
point at which the rocking shaft o' is arrested will determine the force with
which the blow will be struck. The general force of the blows for various
kinds of files is regulated by the set screw q¹, but the variation of this force
for any one file is regulated by the plane w', on which the roller v¹ runs, the
lower the plane the less tension the spring will receive, and hence the less
will be the force of the blow, and vice versa. In this way the form of the
plane w can be modified to suit the form of file to be cut, so that the force of
the blow for cutting the teeth may be proportioned to the varying breadth
of the file, and also to the varying distance of the surface of the file from the
highest point of elevation of the cutting edge.
The line of the cutting edge of the cutter or chisel is directly across the
frame, and the line of motion of the carriage is (as represented by the red
line x....x in Fig. 3) at the same angle to the line of the cutting edge of
the chisel as the axis of the file is to the first range of teeth. After one range
of teeth has been cut on the two faces of the file, it is to be transferred to
another machine, similar to the one above described, except that the line of
motion of the carriage relatively to the line of the cutting edge of the chisel
is reversed, so that the second range of teeth may cross the first. It is not,
however, absolutely necessary that two machines should be employed, as all
the ranges of teeth can be cut on one and the same machine by shifting the

page_text: carriage. For this purpose the ways on which the carriage runs should be
on a second frame, connected with the bed frame by a swivel just under the
chisel or cutter, and the hand or pall h can in that case be made in two parts
to slide on each other, or there may be two hands or palls, one to work the
ratchet wheel for the feed. motion when the carriage is in the position repre-
sented in the Drawings for cutting the first range of teeth, and the second to
act on the said ratchet wheel when the position of the carriage is shifted to cut
the second range of teeth. In the manufacture of files, however, on an
extensive scale, it will be found more economical to cut the first and second
ranges of teeth for each face on separate machines. Instead of reversing the
line of motion of the carriage relatively to the line of the cutting edge for
the two ranges of teeth, so that the force of the blow may be fair and equal
from edge to edge of the file, the same end may be accomplished on essen-
tially the same principle by retaining the same line of motion for the carriage
and reversing the cutter or chisel that is turning it, so that during the cutting of
one range of teeth, its cutting edge shall be diagonal to the line of motion of
the carriage, and during the cutting of the second range the diagonal shall be
reversed; and to adapt the face of the file to the cutting edge in that state of
things, the bed must be inclined transversely, first in one direction and then
in the other, because the line of motion of the cutter being inclined when the
cutter is reversed from the one side to the other, by reason of the obliquity of
the line of motion, the edge will be inclined first in one and then in the
reversed direction from the transverse plane of the face of the file. To effect
this, the carriage may be made in two parts, one above the other, the upper
part being connected with the lower by means of a longitudinal axis, on which
it shall rock, to give the requisite inclination in opposite directions. I prefer,
however, the mode of application above described and represented, as it has
been tried and found to answer satisfactorily.
Having now described the Invention as communicated to me by my foreign
correspondent, I wish it to be understood that under the above in part recited
Letters Patent I claim the method above described (or any mere modification
thereof) of adapting the face of the file to be cut to the cutting edge of the
chisel or cutter, so that an equal force may be applied to the whole breadth
of the file by shifting the file relatively to the cutting edge, substantially as
described. I also claim connecting the chisel with the slide by which it is
operated by means of a joint, so as to give the cutting edge the requisite angle,
and render it self-adapting to the varying texture of the metal to be cut, and
to the varying planes presented by the face of the file (as it passes under the
cutter), by reason of its curved form and the obliquity of the cuts required;

page_text: and, finally, I claim regulating the tension of the spring, or the equivalent
thereof, so as to determine the force of the blow, by causing the plane on the
carriage to act on the said spring or its equivalent, whereby the force of the
blows can be adapted to the form of the file, as described.
In witness whereof, I, the said William Edward Newton, have hereunto
set my hand and seal, this Twenty-third day of January, in the year
of our Lord One thousand eight hundred and fifty-one.