MACHINERY FOR CUTTING THE TEETH OF FILES "
Year: 1882

page_text: PROVISIONAL SPECIFICATION left by the said Paul Ewens at the Office
of the Commissioners of Patents on the 19th May 1882.
PAUL EWENS of Cheltenham in the County of Gloucester
MACHINERY FOR CUTTING THE TEETH OF FILES
"
"IMPROVEMENTS IN
For
In the Specification to Letters Patent granted to W R Lake on the 15th January
1878 No 181 for an invention communicated to him from abroad is described
machinery for cutting the teeth of files. My Invention relates to improvements in
such machinery whereby I am enabled to facilitate its action and render it more
efficient. Instead of fixing the tool. box which contains the cutting chisel and the
appliances for moving it so that the chisel strikes the file blank always at one
fixed angle, I provide means of varying the inclination so that the angle can be
Ι
suited to different sizes and characters of the teeth struck up by the chisel.
this purpose I mount the tool box carrying the chisel and its driving appliances so
that it can be turned partly round on the main shaft as an axis, providing flanges
or cheeks with suitable setting screws or nuts so as to hold the tool box in the
attitude to which it is turned, the direction of the chisel being thus adjustable as
desired within a certain range. The force of the blow of the chisel is determined
by the strain of the spring which works it. In order to vary the strength of blow
during the cutting of a file, as is required when striking the comparatively narrow
teeth at the front angle of the file, I connect a clamp box attached to the spring
and provided with an adjusting screw to the link of an eccentric which is turned
partly round step by step by ratchet and pawl or equivalent mechanism during a
number of the first blows of the chisel, thereby more and more straining the spring
as the teeth become wider across the front angle until they attain their full width,
whereupon the farther straining of the spring ceases. For securing the blanks to
be cut firmly on the advancing bed, I provide two rollers one bearing on the blank
in front of the chisel and one behind it. These rollers are mounted on the ends of
levers which are caused to strain the rollers down by wedges inserted under their
arms. In order to remove the hinder roller out of the way when the cutting of
the blank approaches completion I cause the wedge, which gives the pressure to the
hinder roller to be automatically withdrawn, and thereupon the lever which carries
the roller being counterweighted rises lifting the roller out of the way.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Paul Ewens in the Great Seal Patent Office on the 17th November
1882.
PAUL EWENS of Cheltenham in the County of Gloucester IMPROVEMENTS IN
MACHINERY FOR CUTTING THE TEETH OF FILES
In the specification of Letters Patent granted to W. R. Lake on the fifteenth day
of January 1878 No 181, for an invention communicated to him from abroad is
described machinery for cutting the teeth of files. My invention relates to
improvements in such machinery whereby I am enabled to facilitate its action and
render it more efficient. Instead of fixing the tool-box which contains the cutting
chisel and appliances for moving it so that the chisel strikes the file blank always
at one fixed angle, I provide means of varying the inclination so that the angle
can be suited to different sizes and characters of the teeth struck up by the chisel
For this purpose, I mount the tool box, carrying the chisel and its driving
appliances so that it can be turned partly round on the main shaft as an axis,
providing Hanges or cheeks with suitable setting screws or nuts so as to hold the
tool-box in the attitude to which it is turned, the direction of the chisel being thus
adjustable as desired within a certain range,
Fig 1 of the accompanying drawings is a side view and Fig 2 a front view of
the tool box thus arranged A is the tool-box which is free to turn round the
shaft C as far as is permitted by the screwpins E in the slots of the cheeks D
attached to the tool box. The chisel B can thus have its inclination varied as
indicated at B'.
The force of the blow of the chisel is determined by the strain of the spring
which works it. In order to vary the strength of blow during the cutting of a
file, as is required when striking the comparatively narrow teeth at the front angle
of the file, I connect a clamp box attached to the spring and provided with an
adjusting screw to the link of an eccentric, which is turned partly round step by
step by ratchet & pawl or other equivalent mechanism during a number of the first
blows of the chisel, thereby more and more straining the spring as the teeth become
wider across the front angle until they attain their full width, whereupon the
farther straining of the spring ceases The clamp box F for the springs S which is
partly seen in figs: 1 and 2 is shewn more fully in side view at Fig 3 and in front
view at Fig 4 with the means above described of automatically varying the force
of the blow given by the recoil of the springs S. For this purpose the clamp box F
provided with an adjusting screw f is linked to the eccentric G on a spindle on
which is fixed the ratchet segment I. As this segment is turned tooth by tooth
the eccentric G turning with it draws down the spring box F and thus puts
increased strain upon the springs S. For securing the blanks to be cut firmly on
the advancing bed, I provide two rollers, one bearing on the blank in front of the
chisel and one behind it. Thèse rollers are mounted on the ends of levers which
are caused to strain the rollers down by wedges or springs inserted under their
arms. In order to remove the hinder roller out of the way when the cutting of
the blank approaches completion, I cause the wedge or spring which gives the
pressure to the binder roller to be automatically withdrawn and thereupon the
lever which carries the roller being acted on by a counterweight or spring rises
lifting the roller out of the way This arrangement is shewn by the side view
fig: 5, and transverse section fig: 6, Q being the bed of the machine on which
is held the file blank K that is cut. H is one of the rollers above mentioned which
is pressed firmly down on the blank by the insertion of the wedge spring O under

page_text: the end of the lever on which the roller H is mounted.
For the purpose of
releasing the blank K, the wedge spring O is withdrawn by turning the screw P,
and thereupon a spring h causes the lever and roller H to spring up.
As convenient means for more securely holding the blank on the bed I provide
as shewn in the plan fig: 7. two serrated clamps J J pivotted so that they can
accomodate themselves to the tang of the file K. The pin L of one of these clamps
is made eccentric, so that, on its being turned the one way or the other by a
lever M the clamps are made to grip or to release the tang. The pin L can be
prevented from turning by a lock nut having a handle N.
Having thus described the nature of my invention and in what manner the same
is to be performed, I would have it understood that I make no general claim to
machinery for cutting the teeth of files such as is described in the Specification
No. 181 of 1878 above referred to nor to any parts of such machinery, except those
to which the improvements herein before set forth specially relate, that is to say ;
I claim:-
First Mounting the tool box to turn on the shaft so that the inclination of the
chisel can be varied as herein described with reference to Figs: 1 and 2
Second-Connecting the spring box with an eccentric worked by a ratchet as
and for the purposes herein set forth with reference to figs: 3 and 4
Third Securing the file blank to the bed by rollers actuated as herein described
with reference to figs: 5 and 6
In Witness whereof, I the said Paul Ewens, have hereunto set my hand and
seal this sixteenth day of November, in the year of our Lord, one thousand,
eight hundred and eighty two
PAUL EWENS (L.M.)