IMPROVEMENTS IN MACHINERY FOR CUTTING FILES, OR THE FORMATION OF THE TEETH THEREOF
Year: 1864

page_text: LETTERS PATENT to Elisha Olney Potter, of the State of Rhode Island,
of the United States of America, for the Invention of "IMPROVEMENTS IN
MACHINERY FOR CUTTING FILES, OR THE FORMATION OF THE TEETH THEREOF."
COMPLETE SPECIFICATION filed by the said Elisha Olney Potter at the
Office of the Commissioners of Patents, with his Petition and Declara-
tion, on the 10th September 1864, pursuant to the 9th Section of the
Patent Law Amendment Act, 1852.
⚫ TO ALL TO WHOM THESE PRESENTS SHALL COME, BE IT KNOWN
that I, ELISHA OLNEY POTTER, of the State of Rhode Island, of the United
States of America, have made a new and useful Invention for "IMPROVEMENTS
IN MACHINERY FOR CUTTING FILES, OR THE FORMATION OF THE TEETH THEREOF," and
Lido hereby declare that the nature of my said Invention, and the manner in
which such Invention is to be performed, or in other words, its construction
and mode of operation, are herein-after fully explained, reference being had to
the accompanying Drawings, making part of my Specification.
..Of. the said Drawings, Figure 1 is a top view, Figure 2 a front elevation,

page_text: Figure 8 a rear elevation, and Figure 4 a vertical and transverse section of
my said Invention or improved machine for the formation of the teeth of files.
In carrying out my Invention, I combine with machinery for making in the
file blank the cuts or indentations necessary to the formation of teeth, a me-
chanism for varying tho inclination of the cutter or the position of the filo
blank, so as to maintain such cutter at the same or the necessary angle with
the curved surface of the file blank during the process of making the teeth
thereon, whatever may be the position of the cutter over the blank.
The faces of files as usually made are more or less curved, or are partly
straight and partly curved. These curves usually vary the range or extent of
movement of the cutter of a file-making machine while the file blank may bo
in the act of being cut thereby, the motion of the cutter being the greatest
where the file has the smallest transverse section, in which caso the momentum
of the cutter or its power to indent the blank is the greatest whero it should
be the least.
In my improved machine is comprehended a peculiar mechanism for vary-
ing the pressure or active power of the spring by which the blow of the cutter
is obtained; such mechanism for such purpose being herein-after explained.
In such machine there will also be found tho cutter stock combined with
the cutter carriage by means of a rotary supporter so arranged that its axis of
motion shall be on or about on a level with the upper surface of the bed, and
in or about in a straight line with the cutting edge of the cutter when resting
on the file blank; the object of such arrangement being to enable the cutter
when on the blank to always be for all practical purposes in prolongation of the
axis of motion of the rotary supporter, in order that any rotative movement of
the rotary supporter may not improperly vary the distance between any two
adjacent indentations of the cutter.
There is also in the said improved machine, and combined with the stationary
bed and the mechanism for moving the cutter along longitudinally of a file
blank, a mechanism for varying the feed of the cutter as occasion may require.
For supporting the file blank I make uso of a rocker bed in connection with the
stationary bed; this rocker bed is a common appendage of file-cutting ma-
chines, and therefore is not of my Invention; it is represented in the Drawings
at (a) as sustained within and by the stationary bed A, and so as to be capable
of freely turning transversely on its longitudinal axis, which is on a level with
the upper surface of the stationary bed, the file blank (6) being supported in
and by such rocker bed.
The stationary bed A is sustained by or makes part of the frame B of the
machine, and has in rear of it, and duly supported by parallel guides c, c, a

page_text: movable cutter carriage C, which supports a driving shaft d, whose axis is
arranged on or approximately on a level with the upper surface of the stationary.
bed, and so as to be as near as possible on a level with the top surface of
a file blank when supported by the rocker bed. The carriage C has combined
with it and the cutter stock or carrier E a rotary supporter F, which turns on.
the shaft d as a centre, and against the front face of the carriage C, and serves
also to support in suitable guides or a projection the cutter carrier E. A
cam or wiper f, fixed on the shaft d, serves to elevate the cutter carrier, such
carrier being depressed by means of a spring G, which has one end connected
with the carrier. The other end of the spring is supported by a lever g,
which turns on a fulcrum h, projecting from an adjustable slide i, fastened to
the rotary supporter F by a clamp screw k. A pitman l is jointed at its lower
end to the lever g, and has its upper end resting against the lower edge of a
stationary bar m, which is fixed to the frame B. The lower edge of the bar
m is curved or shaped so as to permit the pitman to either rise or fall more
or less as circumstances may require, while the cutter may be moving over the
file lengthwise, the same being for varying the pressure or active power of the
spring G in such manner or in such degree as to cause the cutter to enter
the file blank a like depth throughout its entire length and however the width
of the blank may vary. The resistance of the file blank to the penetrative
power of the cutter must be the greatest where the blank is the widest, and
the least where it is the narrowest, and were it not for the lever G, the pitman
, and the bar m, formed as described, the indentations made in the blank by
the cutter would not have a like depth throughout the surface of the blank,
but would be the deepost where the file is the narrowest. I would here.
remark that the lever g may be dispensed with, and the pitman / be made to:
rest directly on the spring G; also that besides the said spring G there may be.
one or more springs disposed in the rotary supporter F, and so as to press down
ward the cutter carrier, the object of such auxiliary spring or springs being
to relieve the spring G. The power of the auxiliary spring or springs should
not or should be only sufficient to produce the minimum indentation of the file
blank by the chisel or cutter, the balance of the indentation being effected by
the aid of the spring G. With such auxiliary spring or springs the spring G
will only perform the operation of varying or increasing the depth of the
indentations. The form of the lower edge of the bar m is to be such, with
respect to that of the file to be cut, as to produce such a variation of the force
of the blows of the cutter as may cause them to produce the required depth of.
cut however the width of the blank may change.

page_text: I am aware that it is not new to combine with a movable bed and a cutter
stationary relative to such bed, except in baving up-and-down movements over
the bed, a mechanism for producing a change in the effective power of the
spring for depressing the cutter, the same being shown in Letters Patent
No. 8199 of United States Patents, and therefore I lay no claim to such, my
Invention having reference to the arrangement of such mechanism with the
frame of the machine, a stationary bed, and a movable cutter carriage.
Furthermore, over the said cutter carriage, and secured to the frame B by
clamp screws n, n, passing through slots o, o, there is a plate H, within which
there is a long curved slot p, which receives a central joint pin 9 of a pair of
toggles or progressive levers I, K, one of which is jointed to the carriago C
(as shown at r), while the other is jointed to the rotary supporter F, as shown
ats in Figure 2, the stationary part t of the joints being slotted and affixed
to the supporter F by a clamp screw . During the movement of the carriage
C, so as to cause the cutter to pass along the file blank, the slot p, acting on
the toggles, will vary their angle of separation from one another, so as to rotate
the supporter Fin a manner to vary the angle of inclination of the chisel to
the stationary bed, the variation being such as to cause the chisel to make the.
same or the necessary angle with the surface of the file on whatever part of
such surface it may be cutting. It will be evident that the form of the slot p
may be varied, so as to vary the inclination of the cutter in such manner as
may be desirable while it may be passing along the file.
I would remark that instead of applying directly to the cutter mechanism
as described for varying its inclination with the bed in manner and for the
purpose set forth, the said bed may have such a mechanism, or its equivalent,
applied to it so as to tip it more or less longitudinally while the cutter may be
advancing along the file, the object of the tipping of the bed being to maintain
the cutter at the proper or uniform inclination with that surface of the file
blank which tho cutter may be in the act of indenting.
This latter modification of the machino would be an equivalent for my In-
vention, and I mention it merely to show one of the modes in which I have
contemplated the application of such part of my Invention, viz., that part by
which the inclination of the cutter is varied relatively. to the bed for the pur-
pose of producing uniformity in the slant or the desirable slant of the teeth
made in the file.
'
Figure 8 exhibits a front view of a somewhat different mechanism for turn-
ing the rotary supporter F; it consists simply of a slider a', which slides. ver-
tically between parallel guides b³, b³, attached to the carriage C, and embracos

page_text: a lip c, made on the lower edge of a cam bar d, extending from the framo B.
There is a diagonal or inclined slot in the slider, which receives a pin or stud
projecting from the rotary supporter F.
The next part of my machine to be described is that for moving the cutter
carriage. A screw or worm L, fixed on a shaft u, whose boxes are supported
in brackets v, v, extending from the carriage, engages with a rack M; which
rests, on a rail N of the frame B. The worm is revolved by means of a pawk
v³, supported by a rocker arm w, and working into a. ratchet , fixed on the
shaft of the worm. The rocker arm turns on the shaft u, and is vibrated
up and down by means of an eccentric y, fixed on the driving shaft, and con-
nected with the arm by, a yoke's and a rod a¹, the whole being as shown in
Figures 3, 4, and 5, the latter Figure representing the ratchet and its opera-
tive mechanism in side view. The rack being supported, by the rail N of the
frame B, it follows that when the worm may be, in revolution the cutter
carriage C will be moved along with respect to the bed or the file blank. The
mechanism for varying the feed of the cutter, so as to cause it to make the
teeth finer in some parts of the blank than they may be in others, as occasion
may require, may be thus explained. The rack M, instead of being firmly
fastened to the rail N, is so applied thereto as to be capable of being slid or
moved endwise thereon, and there extends down from the front side of the rack
a wedge or triangular plate 6', the same being as represented in Figure 6,
which is a front view of the rack and its plate 6'. A trapezoidal plate c¹ is
placed between the plate 6' and a vertical plate or bar d³, fixed to the rail N,
the whole being as shown in Figure 6. From the plate c³ two pins or studs
e, e', project and embrace a shaper or curved bar f', which is formed as shown
in Figure 7, and is fixed to the rear surface of the cutter carriage. During
the advance movement of the cutter carriage occasioned by means of the
'action of the worm upon the rack, the operation of the shaper f¹ on the plate
cwill be such as to move such plate vertically, and, thereby cause the rack
to be moved more or less longitudinally, so as to produce a variation of the feed
of the carriage. If the feed of the cutter is to be lessened, the rack is to be
moved in the direction opposite to that by which it is moved by the worm. In
tbis way the feed of the cutter will be varied by the action of the shaper f
the plates b, c, and the. movable rack M operating in combination with the
worm.
.:
I am aware that in the file-cutting machine of Nicholson, patented April
5th, 1864, and described in Letters Patent No. 42,216 of United States Patents,
a movable bed has had a mechanism applied to it for varying the feed motion
of the bed, for the purpose of causing the cutter to cut finer or coarser teeth

page_text: as might be desirable; therefore, I do not claim such, as my improvement
for varying the feed consists in a new mechanism and its arrangement
with the machine frame and a movable cutter carringe operating with a
stationary bed.
What I do claim as my Invention is as follows:-
I claim my improved file tooth cutting machine as made with the stationary
bed (A), the movable cutter carriage C, the rotary cutter stock supporter F,
and tho sliding cutter or the stock thereof, arranged and combined substan-
tially in manner and with operative mechanism to operato as specified.
I also claim the combination of machinery for making the cuts or indenta-
tions in the file blank with mechanism for varying tho inclination of the cutter
relatively to the bed, so as to maintain such cutter at the same or approximately
the same angle with the varying surface of the file blank during the process of
making the teeth thereon.
I also claim the arrangement of the lever 9, the pitman I, and the bar m, with
the frame B, the spring G, the cutter carriage C, or its rotary supporter F,
such lever, pitman, and bar being mechanism for varying the pressure or active
power of the spring by which the blow of the cutter is obtained.
I also claim the mechanism or combination for varying the feed of the cutter
as occasion may require, such combination consisting of the shaper (f), the
plates b', c', bar d', and the studs e', e', the whole being applied together and
to the movable rack M and tho cuttor carriage substantially as and so as to
operate as described.
I also claim the combination, not only of a stationary bed and a mechanism
for moving the cutter longitudinally over the file blank, but a mechanism sub-
stantially as described, or its equivalent, for varying the feed of the cutter as
occasion may require.
I also claim the mechanism or combination for so varying the inclination of
the cutter relatively to the bed as to maintain such cutter at the samo or
approximately the same angle with the varying surface of the file blank during
the process of making the teeth thereof, such combination consisting of the
slotted plate (H), the toggles (I, K.) and the rotary supporter (F), or their
mechanical equivalents, they being combined together and with the frame B
and the cutter carriage substantially in manner and so as to operate as
specified.
I also claim the combination of one or more auxiliary springs with the spring
G and the supporter F, such springs being arranged as and for the purpose
specified.
I also claim the mechanism as shown in Figure 8, such being for the pur-

page_text: pose of so varying the inclination of the cutter relatively to the bed as to
maintain such cutter at the same or approximately the same angle with the
varying surface of the file blank during the process of making the teeth thereof,
the said mechanism consisting of the slotted slider (a³), the guides (63, 63,) the
cam bar (d), and the stud or pin projecting from the supporter F and into
the slot of the slider.
In witness whereof, I, the said Elisha Olney Potter, have hereunto
sot my hand and seal this Twelfth day of August 1864.
ELISHA OLNEY POTTER. (L.S.)