IMPROVEMENTS IN MACHINERY FOR CUTTING FILES
Year: 1865

page_text: PROVISIONAL SPECIFICATION left by William Clark at the Office
of the Commissioners of Patents, with his Petition, on the 6th July
1865. A communication from abroad by William Van Anden, of Pough
Keepsie, Duchess County, State of New York, United States of America.
I, WILLIAM CLARK, of 53, Chancery Lane, in the County of Middlesex,
Engineer and Patent Agent, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN MACHINERY FOR CUTTING FILES," to be as
follows:-
Fig. 1 is a right-hand side view of the machine; Fig. 2 is an end view of
the same; Fig. 3 is a left-hand side view of the same; Fig. 4 is a plan
view of the same; Fig. 5 is a plan view of the table or fixed bed of the
machine; Fig. 6 is a plan view of the movable bed on which the file blank
is secured to be cut; Fig. 7 is a detached sectional view of the chisel holder;
Fig. 8 is a detached view of the hammer and cam and ratchet wheel move-
ment for operating the same; Fig. 9 is a detached side view of the cam for
operating the hammer.
A is a cast-iron frame; on its upper surface is formed a bed or
table B, having a groove C cut in it lengthways; into this groove fits a
tongue a, on the lower side a movable bed D, on the upper surface of which
is secured the file blank. F is the file tang holder, having hooks g' on
its upper back edge, so as to hold the file blank down upon the bed while

page_text: h acts as a binding lever against its edge to hold it against a stud or pin h³
in the face of the bed to prevent any side motion in the tile blank while under
the action of the chisel. His a vertical guide post at the back end of
the machine frame. In the guide way of this post a triangular-shaped feed
gate I works, having on its longest side a tongue ; this engages into a
recess formed in the back end of the bed D, so that as the gate is worked
up or down in the guide way by means of the female screw J at the back
edge of it engaging into the vertical screw K, the bed D is fed up or forward
under the chisel as required to form each cut or tooth. This is effected by
means of a saw or ratchet wheel L secured upon the head of the screw K
rotated by a worm M on the main driving shaft N. To throw the female
screw J attached to the gate into gear with the male screw K a foot lever
secured to the side of the frame A, and is raised for that purpose, and when
the file has been cut is depressed, when. the screws are disconnected and the
weight of the gate causes it to drop down, and thus readjusts the bed D for
placing a new file blank on it. To cause the feed motion of the bed and
file blank to intermit whilst the hammer is making two blows to cut each tooth,
the worm M. on the shaft N is divided into two parts so as to cause the feed
of the file blank to intermit while passing the space between the two parts of
the worm, long enough for the hammer to make two blows before this chisel
is raised from the cut in the blank. P, P, are pawls on the main driving shaft N.
These pawls, as the shaft rotates, operate a ratchet wheel Q running loosely
on the hammer shaft or axis R. At the side of the wheel Q is a tension
spring S, having one end secured to the axis R, and at its opposite side a
detent pin S³, which by its adjustment acts agnir st a pin S³ in the axis R to
hold the ratchet wheel when it reacts after the file has been cut so as to
preserve a uniformity of starting point in the force of the hammer in cutting
the tooth in the file blank, while the increasing force of the hammer is
regulated by the pawls winding up the spring on the ratchet wheel one tooth
at each succeeding blow of the hammer till the pawls come to the blanking
plates on the ratchet wheel, at which point the pawls cease to act, and the
force of the blow of the hammer is kept at its maximum point till the file has
been cut.
It will be obvious that this precise arrangement of the tension spring
and detents on the ratchet wheel Q may be modified in various ways to
accomplish the effect of graduating and regulating the force required to cut
the teeth in the file blank from its point, where it is quite thin and narrow;
and at its middle or shank, where it is much broader, a tension spring or
springs may be secured to the ratchet wheel and the machine frame, and

page_text: by means of the proper adjustinent accomplish the same effects I have
described, and therefore, should circumstances require it, may so arrange the
working of the ratchet wheel to regulate the force of the blows of the hammer.
T is an intercepting bar secured to the end of a lever to working at the side
of the frame A. The object of this arrangement is to lift the pawls from off'
the ratchet wheel Q and intercept the action of the hammer after the file bas
been cut, and whilst the bed D is being restored to its original position, and
the new file blank is being adjusted thereon preparatory for the new cutting
to be made. T is the hammer, secured on an axis R, and having a toe t³
attached thereto. Upon this toe a cam wheel T (secured on the main
driving shaft N) operates to elevate the hammer to make the blow on the
chisel. This cam is made with two objective points on one half its circum-
ference. The object of this is to cause the hammer to repeat its blow during
the intermit of the feed of the file blank, in consequence of the divided thread
of the worm M not rotating the feed ratchet wheel whilst passing the blank
space between the two parts of the worm, and thus make a more perfect
tooth in the file, and at the same time avoid the great risk of breaking the edge
of the chisel, if the necessary force to cut the tooth was concentrated in one
blow. For some kinds of files, however, one blow may be used only, in such
cases I remove the cam T and substitute another with only one objective
point on it. U is the chisel stock secured to an axis u² arranged on the upper
part of the frame of the machine in suitable bearings for such purposes. In
the outer or front end of it is secured the chisel X by means of a packing of
india-rubber V at each side of it, and held in place by means of a binding
screw W. The object of this mode of securing the chisel is to obtain an easy
and certain adaptability in the chisel to find its own level on the surface of
the file blank should there be the least inequality of thickness in it. Y is a
lever arranged on the hammer axis frame, and operated by a cam Z on the
main driving shaft, for the purpose of depressing the chisel just in advance of
the blow of the hammer, so that it may hold the file blank down, and at
the same time be at a state of rest when the hammer strikes the head of the
chisel.