Improvements in File Cutting Machines
Year: 1898

page_text: Date of Application, 19th Sept., 1898-Accepted, 22nd Oct., 1898
COMPLETE SPECIFICATION.
Improvements in File Cutting Machines,
I, DANIEL CORNTHWAITE, of No. 4, Hartington Road, Millhouses, near Sheffield,
Manager, do hereby declare the nature of this invention and in what manner the
same is to be performed, to be particularly described and ascertained in and by
the following statement: -
My invention relates to machines for cutting files of the class having a spindle
or slide for carrying the chisel and which are actuated by a cam, a spring being
also used to acelerate the blow. Such machines as at present constructed are
not reliable for cutting tapered or half-round files in consequence of requiring
alteration and adjustment by hand while the work is in progress to suit the
varying surface.
The object of my improvement is to so construct such machines that by means
of a suitably shaped templet the necessary adjustment will be effected automatic-
ally as the work proceeds.
This object I attain as follows:-Instead of, as is now usual, fixing the driving
shaft with its cam and appurtenances in the main framing of machine, I use
such main framing for carrying the bed and file carrier slides and on the upper
end of framing I fit a separate headstock in which are fitted both the cam shaft
and the chisel slide, so that all the parts in this head move together vertically
as required above the file as it travels along under the cutting chisel as a result
of the application of aforesaid templet.
This will be more readily understood by reference to the accompanying draw-
ings wherein Fig. 1, is a front elevation of machine. Fig. 2 a plan view of same,
sundry unimportant parts being omitted. Fig. 3, is a sectional end elevation
as on line, y, of Fig. 2. Like letters or numerals indicate like parts in all the
figures.
These drawings illustrate a convenient type of machine, although my improved
sliding head may be adapted readily to several other types. I may also here
premise that in order to show the relative positions and uses of various parts, some
well known parts will be described. I only refer to them as examples, other
equivalent parts may be used in connexion with my sliding headstock according
to individual preferences or to meet other requirements.
A, is the main framing of machine and carries in front a bed B, having therein
a semi-circular groove in which slides the file carrier C', said carrier is swivel
jointed to a draw plate D, actuated by the grip exerted through a pair of feed
rolls E, E, which receive their motion from the main driving shaft S, by means
of suitable pulleys G, G¹, with a tension pulley between, the grip of feed rolls is
obtained by mounting the upper roll El, in lever bearings H, H', to which are
applied weights or strong springs I, said levers may be elevated to release plate D,
by means of a weighted lever J, operated by a treadle not shown, said lever also
carries an adjustable presser K, to retain file blank L, in position during the
cutting operation, thus by one motion of the treadle the lever J, is raised lifting

page_text: the presser K, while the other end is depressed so that its angular face comes
into contact with a stud fixed in a slotted lever M, and so partially rotates a pair
of lifting cams N, which carry short rods or props in contact with levers H,
which being also raised relieve the pressure upon the plate 1), and permit of the
several parts being slipped back by hand and set for à fresh start.
When preferred the feed motion may be given to the file carrier by means of
a screw suitably driven and having a sliding nut box formed to receive the
swivel joint.
At the upper part of the main framing A, I form slides or working faces P,
to which I fit a vertically moveable headstock O, having bearings to carry the
main shaft S, with a tripping cam T, operating a lever U, jointed to a vertical
slide V, moving independently in bearings in the main framing, said slide being
supported upon a lever W, the fulcrum being in Q projecting from and moving
with headstock O, preliminary adjustment being effected by means of a screw
and wheel X, attached to bed B. To the front part of headstock O, is fitted a
swivelling frame Y, which contains the reciprocating spindle Z, which carries
the cutting chisel 1, at its lower end, the fall of spindle is accelerated by the aid
of a rubber spring 2, regulated by hand wheel 3, the whole of the operating parts
being thus self-contained and capable of moving together uniformly with the
headstock according to the rise or fall of the guide pulley, 4, in the toe piece 5,
rigidly fixed under headstock 0, the said pulley 4, resting upon a templet 6, of
proper shape to correspond to the contour of the file to be cut, said templet is borne
upon one or more rollers 7, fitted in the bed and is connected to the file carrier C,
or to draw plate D), so as to move endways in unison with movement of the file
blank.
To impart the requisite inertia or steadiness during the cutting process, tension
is applied to headstock by means of adjustable springs 8, or their equivalents:
when once a properly shaped templet has been fitted and the several parts have
been adjusted any number of similar files may be cut without further regulation,
as uniformity of cut will follow automatically.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is:
In a file cutting machine the construction and addition thereto of a sliding
headpiece containing or carrying all the parts actuating the cutting chisel
operating in combination with a templet and connections to enable all such
working parts to be moved together automatically to compensate for variations
in the contour of the file blank during the cutting operation, substantially as
herein described.