Improvements in Machines for Sharpening the Cutting-Tools of Rotary Cutters.
Year: 1899

page_text: PROVISIONAL SPECIFICATION..
Improvements in Machines for Sharpening the Cutting-Tools of
Rotary Cutters.
I, EMIL ALFRED WAHLSTRÖM, of 3, Marien Strasse, Cannstatt, in the Kingdom
of Württemberg, German Empire, Engineer, do hereby declare the nature of this
invention to be as follows:-
-
When working with rotary cutters consisting of a number of fixed cutting tools
great inconvenience has resulted from the fact, that the tools could not be re-
sharpened without being first removed. Therefore the tools had to be taken out
separately, and sharpened. This process was not practicable, because in re-fixing
the cutting tools it was impossible to replace them accurately enough to obtain
a uniform working of all the tools. The result was that the working surface of
the, cutter was not uniform and that exact work could never be obtained.
When however this method was employed and the cutting tools replaced with a
certain amount of care, it needed so much time that under certain circumstances
a new tool could have been made during the time, on another machine.
These conditions proved so much the more unfortunate, as it is impossible to
obtain a more correct and rapid working than with rotary cutters, when the
cutting tools are accurately adjusted. By means of my arrangement the cutting
tools can be sharpened without being taken out of the rotary cutter. The latter.
may remain in the working machine, and my sharpening device may
be attached in a suitable manner to the frame of the working machine or the
whole rotary cutter may be introduced into a sharpening machine of special con-
struction. The latter arrangement is illustrated in the annexed drawing.
A characteristic feature of my invention is that I sharpen the cutting tools
by means of the surface of a rotating sharpening disc, which, besides a rotating
movement, is also provided with an oscillating movement around an axis, to
and from which and the cutting tools to be sharpened the sharpening surface
of the disc can be moved.
In sharpening with the surface of the disc a straight surface is formed on the
cutting tool, whilst a round surface can be sharpened when the disc is also
caused to oscillate.
The diameter of the sharpened round surface of a cutting tool depends upon
the distance of the surface of the sharpening disc from the axis of oscillation.
In my machine I arrange the sharpening disc in such a way, that it can be
moved parallel to its working or sharpening surface, i.e. transversely, to the
axis of rotation. This is preferably done during the sharpening process, so that
the working surface not only remains uniform, but also a uniform sharpening
of the cutting tools is assured.
My invention will be more fully understood with reference to the accompany-
ing drawing, in which similar letters denote similar parts throughout the dif-
ferent views, and in which;
T

page_text: Figure 2 an end elevation of the same,
Figure 3 a plan view,
Figure 4 a perspective view of a sharpened cutting-tool,
Figure 5 is an end elevation of the whole machine,
Figure 6 a plan of the whole machine,.
Figure 7 a plan of the driving mechanism.
.
A compound slide rest B is fixed upon the support or base A. This slide rest B
carries a device C by means of which the rotary cutter is kept in position. The
sharpening-device proper (Figures 1-3) is formed by a rotating sharpening-
disc b capable of oscillation in the plane of its axis. The disc b is movable in
all directions. It is attached upon a spindle w carrying a driving roller. This
driving roller runs between bearings f supported by the arms of a fork g. The
fork 9 is adapted to slide upon a shaft and can be fixed in any position by
means of the clamping screws s. The shaft o is provided at its free extremity
with a handle 2 and is at right angles to the main-shaft h. This shaft h is
rotatably journaled in the bearing and can be moved along its longitudinal
direction by means of a handle p¹. The bearing i can turn around a vertical
shaft. The latter can be raised and lowered in known manner by means of
teeth and a toothed wheel 2 (Figure 5) and fixed in any position by means
of the clamping socket 23.
It is evident that the source of power might be of any suitable kind. In the
example represented in the drawing an electro-motor c is used to drive the disc r.
An endless band runs from the disc r over the disc 3-to-the disc, from there
down again to the discover the disc and back to r¹. The discs and r
are secured to-the-body of the machine in a frame g, whilst the disc is fixed
to an arm q of the vertical shaft-2.-The disc is connected with a smaller
disc see Fig. 3 and rotates round the shaft. The movements of the discr
are transmitted by the disc and the endless cord to the guide rollers and-
and consequently to the roller setting in motion the sharpening disc b.
The working of my machine is as follows:
After the rotary cutter with all its cutting tools has-been_secured upon the
carrier C, the sharpening device (Figures 1-3) is adjusted in height in such a.
manner, that the cutting tools can be sharpened one after the other. Therefore
it is necessary that the movement of the rotary cutter be arrested while each tool
is being sharpened. For this purpose I have fixed to the carrier C a stop n
which takes into holes in the cutter thereby preventing the further rotation of
the same.
The disc b can be accurately adjusted. The distance between the front face m
of the disc b and the centre line of the shaft h forms the radius of the sweep
described by the said front face of the sharpening disc around each of the cutting
tools.
To execute this circular movement the shaft o is turned round the shaft h by
means of the handle p. Evidently the shaft h forms the axis of rotation. This
oscillating movement can be determined at one or at both sides by means of
suitable stops. In Figure 3 the stop t bears against the stop of the bearing i.
A uniform wear of the disc b is attained by the longitudinal movement of the
shajft h.
In sharpening the straight surface 1 of the cutting tool (Fig. 4) the sharpen-
ing disc is moved forwards and backwards parallel to the shaft h (in the line k).
The same is done when sharpening the round surface.
Figure 4 illustrates a cutting tool and it is easy to understand that the straight
surface 1 is sharpened when the disc b does not oscillate round the shaft h while
by swinging the disc b round the shaft h, the round surface 2 of the knife will
be sharpened. The angle of the straight surface 1 in respect to the centre line
of the cutting tool is determined by the stops tt, but as the position of these
stops can be varied at will, (not represented in the drawing) it will be evident
that this angle also can vary. A proper adjustment of the rotary cutter can be

page_text: effected by the slide rest B which is fixed upon the support or base A, and is
provided with a swivelling piece.
In the construction represented in the drawings it is assumed that the rotary
cutter a is employed with a special sharpening machine. Evidently the rotary
cutter may remain in the working machine, and the sharpening device, as repre-
sented in Figures 1-3 can be temporarily fixed to such machine in a suitable
manner.
Improvements in Machines for Sharpening the Cutting-Tools of
Rotary Cutters.
I, EMIL ALFRED WAHLSTRÖM, of 3, Marienstrasse, Cannstatt, in the Kingdom
of Württemberg, German Empire, Engineer, 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:.
-
When working with rotary cutters consisting of a number of fixed cutting tools
great inconvenience has resulted from the fact, that the tools could not be re-
sharpened without being first removed. Therefore the tools had to be taken out
separately and sharpened. This process was not practicable, because in re-fixing
the cutter tools it was impossible to replace them accurately enough to obtain.
a uniform working of all the tools. The result was that the working surface of
the cutter was not uniform and that exact work could never be obtained.
When however this method was employed and the cutting tools replaced with a
certain amount of care, it needed so much time that under certain circumstances:
a new tool could have been made during the time on another machine.
These conditions proved so much the more unfortunate, as it is impossible to
obtain a more correct and rapid working than with rotary, cutters, when the
cutting tools are accurately adjusted. By means of my arrangement the cutting
tools can be sharpened without being taken out of the rotary cutter. The latter
may remain in the working machine, and my sharpening device may
be attached in a suitable manner to the frame of the working machine or the.
whole rotary cutter may be introduced into a sharpening machine of special con-
struction. The latter arrangement has been illustrated in the drawings, filed.
with the Provisional Application.
A characteristic feature of my invention is that I sharpen the cutting tools.
by means of the surface of a rotating sharpening disc, which, besides a rotating
movement is also provided with an oscillating movement around an axis, to.
and from which and the cutting tools to be sharpened the sharpening surface
of the disc can be moved.
In sharpening with the surface of the disc a straight surface is formed on the:
cutting tool, whilst a round surface can be sharpened when the disc is also
caused to oscillate.
The diameter of the sharpened round surface of a cutting tool depends upon
the distance of the surface of the sharpening disc from the axis of oscillation.
In my machine I arrange the sharpening disc in such a way, that it can be
moved parallel to its working or sharpening surface, i.e., transversely, to the
axis of rotation. This is preferably done during the sharpening process, so that

page_text: now only reform, but also a uniform sharpening
of the cutting tools is assured.
My invention will be more fully understood with reference to the drawing,
filed with the Provisional Specification and in which similar letters denote
similar parts throughout the different views, and in which;
Fig. 1 shows a side-view of my sharpening-device,
Fig. 2 an end elevation of the same,
Fig. 3 a plan view,
Fig. 4 a perspective view of a sharpened cutting-tool,
Fig. 5 is an end elevation of the whole machine,
Fig. 6 a plan of the whole machine,
Fig. 7 a plan of the driving mechanism.
A compound slide rest B is fixed upon the support or base A. This slide rest B
carries a device C by means of which the rotary cutter is kept in position. The
sharpening-device proper (Figs. 1-3) is formed by a rotating sharpening-
disc b capable of oscillation in the plane of its axis. The disc b is movable in
all directions. It is attached upon a spindle w carrying a driving roller: This
driving roller runs between bearings supported by the arms of a fork g. The
fork is adapted to slide upon a shaft o and can be fixed in any position by
means of the clamping screws 8. The shaft o is provided at its free extremity
with a handle and is at right angles to the main-shaft. This shaft is
rotatably journaled in the bearing and-can be moved along its longitudinal
direction by means of a handle p The bearing i can turn around a vertical.
shaft z. The latter can be raised and lowered in. known manner by means of
teeth-and-a-toothed wheel 2 (Fig. 5) and fixed in any position by means
of the clamping socket
any suitable kind. In the
is used to drive the disc r¹.
to the disc r, from there
It is evident that the source of power might be of
example represented in the drawing an electro-motor e
An-endless band runs from the dise rover the disc
down again to the discover the-disc-and back to . The discs 2 and
are secured to the body of the machine in a frame whilst the disc is fixed
to an arm of the vertical shaft z. The disc is connected with a smaller
disc (see Fig. 3) and rotates round the shaft h. The movements of the disc r
are transmitted by the disc and the endless cord to the guide rollers
and consequently to the roller setting in motion the sharpening disc b.
The working of my machine is as follows:
and
After the rotary cutter with all its cutting tools has been secured upon the
carrier C, the sharpening device (Figs. 1-3) is adjusted in height in such a
manner, that the cutting tools can be sharpened one after the other. Therefore
it is necessary that the movement of the rotary cutter be arrested while each tool
is being sharpened. For this purpose I have fixed to the carrier C a stop n
which takes into holes in the cutter thereby preventing the further rotation of
the same
The disc b can be accurately adjusted. The distance between the front face m
of the disc b and the centre line of the shaft forms the radius of the sweep
described by the said front face of the sharpening disc around each of the cutting
tools'
To execute this circular movement the shaft o is turned round the shaft by
means of the handle p. Evidently the shaft h forms the axis of rotation. This
oscillating movement can be determined at one or at both sides by means of
suitable stops. In Fig. 3 the stop t bears against the stop of the bearing i.
A uniform wear of the disc b is attained by the longitudinal movement of the
shaft h.
In sharpening the straight surface 1 of the cutting tool (Fig. 4) the sharpen-
ing disc is moved forwards and backwards parallel to the shaft (in the line kl).
The same is done when sharpening the round surface."
Fig. 4 illustrates a cutting tool and it is easy to understand that the straight

page_text: surface 1 is sharpened when the disc b does not oscillate round the shaft h, and
that while swinging the disc round the shaft h, the round surface 2 of the
knife will be sharpened. The angle of the straight surface 1 in respect to
the centre line of the cutting tool is determined by the stops tt, but as the posi-
tion of these stops can be varied at will, (not represented in the drawing) it will
be evident that this angle also can vary. A proper adjustment of the rotary
cutter can be effected by the slide rest B which is fixed upon the support or
base A.
In the construction represented in the drawings it is assumed that the rotary
cutter a is employed with a special sharpening machine. Evidently the rotary
cutter may remain in the machine in which it is being used, and the sharpening
device, as represented in Figs. 1-3 can be temporarily fixed to such machine
in a suitable manner.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is:-
1. In a machine for sharpening the cutting tools of cutters, the combination of
a device holding the tools to be sharpened, with a rotatable sharpening disc,
capable of swinging round an axis parallel to its working surface, for the purpose
and substantially as described.
2. In a machine for sharpening the cutting tools of cutters, the combination
of a rotatable sharpening-disc b fixed upon the arms of a movable fork g, with
a shaft h rotatably fixed in a bearing i, a rod z supporting said bearing i, driv-
ing rollers effecting the rotation of the sharpening disc and means to swing the
disc b with the fork g round the axis of the shaft h, for the purpose and
substantially as described.
3. In a machine for sharpening the cutting tools of cutters, the combination of
a movable shaft h rotatably fixed in a bearing with a shaft o rigidly connected
to the shaft h rectangularly to the same, a fork 9, adapted to slide upon the
shaft o, screws s fixing the fork g to said shaft o, a shaft w rotating in bear-
ings supported by the arms of the fork, a sharpening disc m fixed to the
extremity of the shaft w and means to give motion to the sharpening disc, sub-
stantially as described.
Dated this and dan er
1000
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.