pre-cutting machines.
Year: 1897

page_text: pre-cutting machines.
I, LUDWIG RUDOLF WINTERHOFF, of 1, Hermannstrasse, Remschied, Germany,
Machinist, do hereby declare the nature of this invention to be as follows:
My invention relates to file-cutting machines and has for its object, first, to
render the file bed self adjusting so as to accurately level the surface of the file
in the transverse direction for each stroke of the chisel and so ensure substantial
uniformity of depth of the cut and enable the slide on which the file is bedded
to be fed forward after each cut by mechanism acting directly thereon; secondly,
to enable the strength of blow of the chisel to be varied by hand or automatically
at each stroke according to the variation of the surface of the file in the longitu-
dinal direction,
The file-supporting slide may be said to float being supported with the least
possible friction in such manner that it is free to oscillate so as to adapt itself
to the variations in the transverse direction of the surface of the file, and for this
purpose the slide is made convexly cylindrical at the underside and is supported
in a correspondingly concave guide in the bed frame, in which it is fed along
after each cut of the chisel, by direct acting mechanism which leave it constantly
free to accommodate itself to the file as above mentioned, under the guidance
of a presser against which the surface of the file bears, across its whole width
so as to be thereby caused to constantly level itself along the line of cut.
The slide is fed by a leading screw mounted below the level of the concave
guide, and acting on the slide through a nut engaging with the slide in such
manner as not to interfere with the lateral oscillation thereof. For this purpose
and to enable the slide to be quickly disengaged and returned to the starting
point the nut is formed as a half nut on the end of an arm playing in a trans-
verse slot in the slide and pivoted to the latter at a point in its axis of oscillation
the pivot being eccentrically journalled in the slide so as by its partial rotation
to put the half nut in or out of engagement with the leading screw.
The reciprocating chisel carrier is operated by a spring compressed at each
stroke by the action of a conical snail cam adjustable longitudinally apon its
shaft by means of a hand or automatically operated screw so as to vary the effec-
tive radius of the cam and consequently the degree of compression of the spring
according to the strength of blow required, the adjustment when effected auto-
matically being under the control of a feeler bearing on the file so as to respond
to variations of its surface in the longitudinal direction, and acting through
suitable mechanism on the cam-adjusting screw. This feeler when used may
fulfil also the function of the guide by which the lateral levelling of the file
is effected.

page_text: Improvements in File-cutting Machines.
I, LUDWIG RUDOLF WINTERHOFF, of 1, Hermannstrasse, Remschied, Germany,
Machinist, 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 file-cutting machines and has for its object, first, to
render the file bed self-adjusting so as to ensure the surface of the file being accu-
rately levelled in the transverse direction for each stroke of the chisel, and conse-
quently ensure substantial uniformity of depth of the cut and enable the slide on
which the file is bedded to be fed forward after each cut by mechanism acting
directly thereon; secondly, to enable the strength of blow of the chisel to be
varied by hand or automatically at each stroke according to the variation of the
surface of the file in the longitudinal direction.
Reference is to be had to the accompanying drawings forming part of this
specification wherein Figures 1 and 2 are respectively a front and an end eleva-
tion (both partly sectional) of a file-cutting machine embodying my improve-
ments, the mechanism being adapted to enable the strength of blow of the chisel
to be varied by hand. Figures 3 and 4 are corresponding views of a similar
machine adapted to enable the strength of blow of the chisel to be varied auto-
matically. Figure 5 illustrates a modified form of cam.
The slide a on which the file A is bedded is supported with the least possible
friction in such manner that it may be said to "float," that is to say it is free to
oscillate laterally so as to adapt itself to the variations (in the transverse direc-
tion) of the surface of the file and permit of the latter being constantly levelled
along the line of cut. For this purpose the slide a is made convexly cylindrical
at the underside, and is supported in a correspondingly concave guide in the
bed frame of the machine and after each cut of the chisel is fed along in said
guide by a leading screw (not shewn) mounted below the level of the concave
guide, and acting on the slide in such manner as not to interfere with the lateral
oscillation thereof. Means may also be provided for enabling the nut and lead-
ing screw to be readily disengaged for the purpose of enabling the slide to be
quickly returned to the starting point.
The means whereby the file A is caused to present its surface parallel in the
direction of its width to the cutting edge of the chisel d, consists of a plunger c
sliding freely in a guide c¹ parallel to the direction of the blow of the chisel, the
plunger c (which is prevented from turning in its guide) carrying at its lower
extremity a feeler-blade e whose edge rests as indicated upon the surface of the
file A in a transverse direction and is adjustable to meet that surface close to, and
parallel with, the cutting edge of the chisel d. Contact between the blade e and
file A is maintained, and elastic pressure by the former upon the latter is ensured,
by means of either a spring or a weight facting through lever mechanism upon
the plunger cas indicated. The feeler-blade e is thus free to accommodate itself
to variations in the surface configuration of the file regarded longitudinally, but
being held rigidly in the transverse direction, compels the file, "floating" (with
its supporting slide a) on the guide 6 as already described, to accommodate itself
laterally to the blade e and so present its surface on the line of cut, truly 4
parallel to the cutting edge of the chisel d.
The chisel d delivers its blow under the impulse of a spring contained in a
casing g and bearing upon a piston attached to the upper end of the chisel carry-
ing ram h which works in guides as usual, the spring being compressed at each
stroke by the upward movement of the ram which is alternately lifted and let 5

page_text: fall by a revolving snail cam i engaged by an arm h¹ projecting from the ram h,
said arm being, if desired, provided with a friction roller h², as in Figures 3 and 4.
Variation in the degree of compression of the spring, so as to produce any
desired graduation in the strength of blow of the chisel d, is brought about by
so increasing or diminishing the effective radius of the snail-cam i as to cause a
corresponding increase or diminution in the height of lift of the ram h. To this
end the cam i is made tapering in the direction of its axis of rotation and is
mounted upon its shaft with a groove and feather connection so as to be longi-
tudinally adjustable in order to bring any portion of its length to act upon the
arm h¹. This longitudinal adjustment of cam i upon its shaft ; may be effected
either by hand. or automatically. In the former case (illustrated in
Figures 1 and 2) the fork k engaging with a peripheral groove in the boss
of the cam i, is mounted to move as one with the nut upon a leading screw
rotated at will by the operator, through the hand wheel 2. In the latter case
(illustrated in Figures 3 and 4) the fork k forms the extremity of one arm of a
lever m which is caused through suitable connecting mechanism, to vibrate in
accordance with, and in suitable proportion to, the rise and fall of the feeler-
blade e.
In the case however of flat files, or those whose longitudinal curvature
is but slight, it is generally advisable to connect the lever m not to the feeler
blade e as just described, but to a similar feeler making contact with a suitably
shaped templet or guide fixed to the slide a alongside of the file to be cut.
Figure 5 shews an end view of a double-faced cam by means of which two
blows of the chisel, instead of one, are given for each revolution of the cam shaft.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I claim
is:―
1. In a file-cutting machine a file-supporting bed having a convexly-cylin-
drical under surface supported in a concavely-cylindrical guide so as to float or
be free to rock laterally in the manner and for the purpose specified.
2. In a file-cutting machine a floating or laterally rocking file-supporting bed
adapted also to slide longitudinally as described, in combination with a feeler
adapted to press upon the file so as to constrain the surface to be cut to assume a
position parallel to the cutting edge of the chisel as described.
3. In a file-cutting machine a floating or laterally rocking file-supporting bed
adapted also to slide longitudinally as described, in combination with a feeler
pressed yieldingly upon the file so as to accommodate itself to variations of level
of the file surface in the longitudinal direction, but rigid in the transverse direc
tion of the file so as to govern the position of the file surface in the direction
of the line of cut as specified.
4. In a file-cutting machine the combination with the chisel-carrying ram, of
a snail-shaped cam made tapering in the direction of its length and mounted
adjustably with regard to the said ram so as by such adjustment to vary the
effective radius of the cam and the force of the blow substantially as specified.
5. In a file-cutting machine having a file-supporting bed adapted to float of
rock laterally under the control of a presser acting on the surface of the file, and
with a tapered cam of adjustably variable effective radius, of a feeler bearing upon
the file (or upon a guiding surface in relation thereto) and acting on the cam
adjustment mechanism so as to cause the strength of the blow to be varied in
accordance with the variation of level of the said surface substantially as specified.
Dated this 31st day of May 1898.
A. M. & WM. CLARK,
Chartered Patent Agents, 53, Chancery Lane, London.