An Improvement in File-cutting Machinery.
Year: 1890

page_text: Date of Application, 22nd Oct., 1890-Accepted, 22nd Nov., 1890
COMPLETE SPECIFICATION.
An Improvement in File-cutting Machinery..
We, JOSEPH FISCHER and THEODOR FISCHER, both of I Bankgasse 2, Vienna,
Austria, Merchants, 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:-
'
Our invention has mainly reference to the construction of file cutting machine
described in an application for Letters Patent filed by us on 5th August 1890,
No. 12,253. In the Specification to the said application was described the use of
guide rails on which a lever was made to slide which controlled the mechanism that
moved the rests carrying the files, such lever, in sliding along the guides, being made
to control the mechanism so that, the cuts were effected closer together at the point of
the file than at the other part.
Files cut by band are generally preferred to machine-cut files on account of a certain
irregularity in the cuts that occur in hand cut files, which prevent the formation of
grooves in filing, while with machine cut files, the cuts being perfectly regular, straight
rows of file-teeth are produced, which cause lines or grooves to be formed in the
work.
:
Our present invention has for its object, to enable the machine described in our
above, named application. to cut files in such a manner that the cuts will have an
irregular appearance, similar to that of files. cut by hand, the files produced in this
manner being even more effective in their action than those cut by hand.
For this purpose, instead of constructing the before mentioned guide rails with a
perfectly straight surface, as described in our said Specification, we form the surface
with irregular projections or undulations, so that as the before mentioned lever with
its roller passes over the said irregular surface, it effects an irregular motion of the
toothed segments upon which it acts, and these in turn effect an irregular action of
the feed motion of the slide, whereby an irregular cut of the file is effected.
The greater the number of irregularities that the guide rail has, the more irregular
will be the cut.
The accompanying drawing shews so much of the machine described in our said
application as is necessary to explain our said improvement.
Fig. 1 shews a part side view of the machine shewing the sliding rests D D for the
files, together with the operating mechanism ;
Fig. 2 shews a cross section of the rests, and
Fig. 3 a longitudinal section through the same.
The rests D D are carried by and slide upon rest-standards C along which they are
moved with a step-by-step motion by the screw spindles u, rotated intermittently
through toothed gearing from an excentric on the driving shaft of the machine, as
described in our said former application, the motion of the screw spindle being
imparted to the rests D by the nuts x, to which are attached toothed racks a gearing
with a pinion r on the spindle of a toothed segment R. With this segment gears a
second segment S connected to a lever S2 having a roller S¹ that bears upon the
surface of the guide rail P. This rail is not formed with a straight surface, as described
in our former Specification, but has a number of projections or undulations p as above
described, the action of which is that, as the rests D are made by the screw spindle to
travel with a step-by-step motion along the rest-standards while being acted upon by
the file cutters in the manner described in our former application, the lever S³ in being
alternately raised and lowered in an irregular manner in passing over the undulations p
as it is carried along with the rests D, is made to actuate the nut a through the
gearing RS, r and rack a in such manner as to produce at irregular intervals a relative
motion between the nut and the rest D alternately in opposite directions, and this

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relative motion will cause the forward motion of the rests D to be somewhat retarded
and accelerated at irregular intervals, which has the effect of making the cuts more or
less irregular, in a similar manner to the cuts produced by hand.
This irregularity of the cuts will prevent any formation of straight. rows of file teeth
such as occur in ordinary machine cut. files, and which, as before stated, produce
grooves or lines in the work.
The other parts of the machine are of precisely the same construction as described in
our former application, and need therefore not be further referred to.
The form and number of the irregularities or undulations p, p, may be varied in any
desired manner.
It will be evident that our said invention is equally applicable to all file cutting
machines in which the rest carrying the files is actuated by means of a screw spindle
and nut.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
In a machine for cutting files wherein the rest carrying the file is fed forward by a
screw spindle actuating a nut controlled by a lever such as S2, the use of a guide rail
such as P for the lever S², which guide rail has projections or undulations formed
along its acting surface whereby an irregular forward motion of the file blanks under
the cutters is produced, for the purpose of preventing the formation of straight rows of
file teeth, substantially as described.
Dated this 22nd day of October 1890.
ABEL & IMRAY,
Agents for the Applicants.