IMPROVEMENTS IN MACHINERY FOR ROLLING AND CUTTING FILES AND RASPS
Year: 1863

page_text: LETTERS PATENT to Francis Preston, of the City of Manchester, Engineer,
for the Invention of "IMPROVEMENTS IN MACHINERY FOR ROLLING AND
CUTTING FILES AND RASPS."
Sealed the 15th March 1864, and dated the 29th September 1863.
PROVISIONAL SPECIFICATION left by the said Francis Preston at the
Office of the Commissioners of Patents, with his Petition, on the 29th
September 1863.
I, FRANCIS PRESTON, of the City of Manchester, Engineer, do hereby declare
the nature of the said Invention for "IMPROVEMENTS IN MACHINERY FOR ROLLING
AND CUTTING FILES AND RASPS," to be as follows:-
My improvements in machinery for rolling the blanks of files and rasps
consist in making the dies which fit upon the roller in segments, which are
held upon the roller by means of washers and nuts or set screws.
The first part of my improvements in machinery for cutting files and rasps
consists in applying a taper cam or cone cam to lift the ram or tail of the
hammer, whereby a different weight of blow is given to the chisel when
cutting taper files or rasps; but when cutting files or rasps which do not
require a varying blow the cam continues lifting in one place. The mode of
varying the weight of the blow may be attained by using an intermediate lever
between the cam and the ram and elevating or depressing the fulcrum of the
lever when in motion, or the same may be accomplished by shortening or
lengthening the intermediate lever when in motion, so as to be acted upon at
the various diameters of the cam.
Another part of my Invention consists in having a spring or springs acting
upon the ram or slides, either directly or attached to a small roller pressing

page_text: upon
the ram to keep the ram firm against the slides so as to cause the chisel
to strike at equal distances upon the file or rasp.
Another part of my Invention consists in making a hole lengthways through
the ram or chisel holder, and at the top side of the ram is placed a screw and
lock nut which binds on the top of the chisel so as to allow the chisel to be
raised or lowered according to the length of chisel required. This arrange-
ment may be modified by placing washers on the top side of the chisel between
the screw and the chisel, or washers may be placed on the chisel shank
between the ram and the bottom part of the chisel.
Also my improvements consist in applying a worm and wheel or segment of
a wheel attached to the bed for bringing it to the face of the chisel or into the
required position.
And, lastly, my improvements consist in moving the bed by means of a
worm and wheel and making the worm of an irregular pitch, so as to allow
the bed to be stationary or nearly stationary, as required, during the time the
file or rasp is receiving the cut.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Francis Preston in the Great Seal Patent Office on the
26th March 1864.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FRANCIS
PRESTON, of the City of Manchester, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-ninth day of September, in the year of our
Lord One thousand eight hundred and sixty-three, in the twenty-seventh
year of Her reign, did, for Herself, Her heirs and successors, give and grant
unto me, the said Francis Preston, Her special license that I, the said
Francis Preston, my executors, administrators, and assigns, or such others as
I, the said Francis Preston, 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 "IMPROVE-
MENTS IN MACHINERY FOR ROLLING AND CUTTING FILES AND RASPS," upon the
condition (amongst others) that I, the said Francis Preston, 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,

page_text: and cause the same to be filed in the Great Seal Patent Office within six
calendar months next and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Francis Preston, do hereby declare
the nature of my said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement (that is to say) :-
The nature of my improvements in machinery for rolling the blanks of files
and rasps consists in making the dies in segments, which are held upon a
roller by means of washers and nuts or set screws.
My improvements in machinery for cutting files and rasps consist, first, in
certain combinations of machinery for varying the force of the blow in cutting
taper files or rasps.
Secondly, in the application of a spring or springs acting upon the ram to
keep it firm against the slides and still allow it to yield when the chisel is
cutting.
Thirdly, in making a hole lengthways through the ram or chisel holder,
through which passes a rod with regulating nuts; this rod is set according to
the length of the chisel employed. This arrangement may be modified by
placing washers on the top side of the chisel between the screw and the chisel,
or washers may be placed on the chisel shank between the ram and the bottom
part of the chisel.
Fourthly, in applying a worm and wheel or segment of a wheel to the bed
for bringing it to the face of the chisel, or into the required position.
And, lastly, in moving the bed by means of a worm and wheel; the word
having an irregular thread to allow the bed to be stationary. or nearly
stationary, when the file or rasp is receiving the cut.
And in order that my Invention may be fully understood I will proceed to
describe the accompanying Sheet of Drawings.
Figures 1 and 2 represent my improvements in machinery for rolling the
blanks of files and rasps. a is the axle of a roller supported in side standards;
to the axle a is fixed the spur pinion a', which is moved round alternately in
opposite directions by the rack d' fixed to. the slide d, as described in the
Specification of former Letters Patent granted to me on the First of February
One thousand eight hundred and fifty-six, Number 274. To the axle a is
keyed the bush b, on which the segment c is secured by the nut a3 and
washer a³; the segment c is tapered at one edge and shouldered at the other,
the taper and shoulder fitting in recesses in the bush 6 and washer a³, conse-
quently, when the nut a is tightened up the segment is securely held, and
when the nut is removed. it is easy to change the segment for one, with

page_text: different shaped grooves; the segment shewn in the Drawing is for rolling
half-round files. To the slide d is fixed an adjustable plate d which is pro-
vided with two grooves, the one corresponding to the groove in the segment c
is for rolling the file blank on edge, and the other is for rolling the blank
when flat. In working the machine the file blank is placed alternately in
each groove.
Figures 3 and 4 are two views of a file-cutting machine to which my
improvements are applied. is the foundation plate; f, the standard; 9, the
bed plate; h, the bed; i, the driving shaft; and j, the ram to which the
chisel k is attached; these and all the other parts requisite to complete the
machine which are not shewn in the Drawing, and not particularly referred to
hereafter, are made in the usual manner; is a taper or conical cam, shewn
full size in Figures 5 and 6, for lifting the ramj or the tail of the lever, as
will be described hereafter; this cam is connected to the shaft i by a key and
groove, and it is moved to and fro by means of the screw m, one end of which
is connected to the cam by a key, and the other end has a thread fitting in
the hand wheel m', the boss of which forms a nut. To the screw m is fixed a
boss m³, the key for holding this boss passes into a slot in the bracket m³ to
prevent the screw from turning with the hand wheel. At the smaller end of
the cam is a parallel portion which acts on the bowl of the ram j when a
light uniform blow is required, but when it is requisite to vary the weight of
the blow in cutting taper files the cam is moved gradually by turning the hand
wheel m¹ further under the bowl of the ram j, thus increasing, when the cam
revolves, the compression of the spring coiled round the head projecting
from the ram j and the lift of the ram. It is evident that in cutting parallel
files the position of the cam when set to give the desired force of blow remains
unaltered.
The mode of varying the weight and force of the blow may be modified, as
shewn in Figure 7. In this arrangement the cam l acts upon the intermediate
lever z hinged to the fulcrum ¹, the other end of the lever z is connected to
the ram by the regulating screw 23. The fulcrum 2' may be stationary, and
the cam traversed along its shaft i, as above described, or the variation in
the force of the blow may be produced by altering the position of the fulcrum z¹
so as to increase or diminish the lengths of the two arms of the lever; in this
latter case the cam / would remain stationary on the shaft i. To the lower
end of the ram j, which works up and down as usual in V-grooves in the
standard f, is connected one end of the link n, the other end of which is jointed
to a regulating screw n passing through the spring o fixed to the standard;
this spring always holds the ram against one side of the V-grooves of the slide,

page_text: in which it moves and causes the chisel to act at equal distances on the file;
the spring also allows the chisel to yield according to the bevel of the cutting
edge when the blow is given, thus obtaining the same result as in hand-cut
files; or instead of a drawing spring at the back of the ram, as shewn, a
pressing spring with a bowl or small roller may be applied to the front of the
ram. The head of the ram j is guided by the screwed bush f¹ in the upper
part of the standard f; this head and the ramj are bored out lengthwise
for the rod p to pass through. The lower end of this rod bears upon the end
of the shank of the chisel k, and the upper end is screwed and fits in a screw
cut in the upper end of the head 3; by turning this screw round and securing
it by the lock nut shewn, the end of the rod p is kept at all times against the
end of the chisel, the length of which is gradually reduced by sharpening.
The above arrangement for compensating for the varying length of the chisel
may be modified by placing washers on the top side of the chisel between the
end of the rod p and the chisel, or washers may be placed on the shank of the
chisel between the lower end of the ram and the bottom part of the chisel.
To the bed h supporting the file or rasp to be cut, which is made partly
cylindrical, as usual, is fixed the toothed segment », in which gears the worm s,
the axle of which is supported in bearings fixed to the slide or cradle g of the
bed h. By turning round the worms the bed h is moved so as to bring the
edge or face of the file in line with the face of the chisel k, or into any other
required position. The slide of the bed his moved to and fro along the foun-
dation plate e by the screw u, as usual, but instead of driving the screw by a
catch and ratchet wheel, as now customary, I fix to the end of the screw u
the toothed wheel v, in which gears the worm w; this worm has an irregular
thread, that is to say, some parts of the thread are at right angles or nearly
so to the axis, and others are diagonal; by this means, when the worm is
turned round by the strap or chain x and pulleys ¹ and w', or in any other
convenient manner, the bed h may be stationary, or nearly so, when the file or
rasp is receiving its cut, and it will be moved the requisite distance for cutting
the next tooth while the chisel is ascending and descending.
In witness whereof, I, the said Francis Preston, have hereunto set my
hand and seal, the Twenty-fourth day of March, One thousand eight
hundred and sixty-four.