METHOD FOR CIRCULAR GRINDING DURING PRODUCTION OF TOOLS MADE
OF HARD METAL AND CIRCULAR GRINDING MACHINE FOR GRINDING
CYLINDRICAL STARTING BODIES DURING THE PRODUCTION OF TOOLS MADE
OF HARD METAL
The invention relates to a method for circular grinding during the production of
tools made of hard metal on a circular grinding machine that has a workpiece
spindle head and a tailstock, whereby work commences using a round rod
comprising a starting material.
According to the prior art known from commercial practice, as a rule work
commences starting with round rods made of sintered hard metal. These rods
then have a grinding overmeasure for the shaft region and are cut to the
necessary tool length, or the starting bodies are brought to the required shaft
dimension for their entire length using so-called centerless grinding and are then
cut into lengths. From the bar pieces that were cut into lengths individually, the
tool is then produced from the whole by grinding. For this, the hard metal tools
are received during grinding between hollow center punches, tips, or in a chuck.
Grinding occurs either using the conventional grinding method or using the
rough grinding method by means of diamond grinding wheels. In any
case multiple instances of re-chucking are required because first the individual
bar pieces are produced by grinding and cutting into lengths, where necessary in
the reverse sequence as well, and then in subsequent grinding processes that
take place on other machines the tool contours are ground and cutting,
gradation, spiral cutting, and the like occur.

The known methods in accordance with the prior art work satisfactorily, however
they entail the risk of errors in the trueness of the run. These errors are related
primarily to multiple instances of re-chucking. Even if work is performed with
great attention to precision, such errors in the trueness of the run cannot always
be avoided. They are entirely and unpleasantly noticeable on the finished tool.
This is particularly true of high-speed processing, for instance in aircraft
construction. In this case, cutting tools are used that work at speeds of 30,000
to 60,000 rpms When processing the light metal parts that are widely used in
aircraft construction, even the smallest error in the trueness of the run on the
tool is disturbingly noticeable.
The object of the invention is therefore to improve the method known from the
prior art such that errors in the trueness of the run are avoided with certainty
and at comparable production costs.
This object is achieved in accordance with the following method steps:
a) Gripping the round rod, whose length is a multiple of the length of a
single tool, in a chuck of the workpiece spindle head that when the chuck
is

released enables axial displacement of the round rod, whereby an end region of
the round rod that projects out of the workpiece spindle head faces the tailstock;
b) Grinding at least one steady rest on the end region of the round
rod that projects from the workpiece spindle head and placing the steady on the
steady rest;
c) Grinding a first end-face taper on the end face of the round rod
that faces the tailstock;
d) Secure-clamping fitting of the first end-face taper with a hollow
center punch that is located on a sleeve of the tailstock;
e) Circular grinding of the end region of the round rod that projects
from the workpiece spindle head over approximately the entire length that
corresponds to the individual tool up to its circular-ground final contour;
f) Cutting off the thus finish-ground individual tool from the round
rod;
g) Releasing the chuck of the workpiece spindle head, which to this
point has remained clamped, moving the round rod in the workpiece spindle
head in the direction of the tailstock, and then loading the chuck, whereby an
additional end region of the round rod, which end region is to be processed,
projects from the workpiece spindle head.
According to the inventive method, thus "work is performed on the
running rod". For this, the round rod that comprises sintered hard metal and

that can fot instance have a length of 300 to 400 mm, is gradually moved
through the chuck of the workpiece spindle head and securely clamped each
time a specific end region of the round rod that approximately corresponds in
length to the tool to be produced projects from the workpiece spindle head and
faces the tailstock. The special feature of the inventive method is that the
projecting end region, even while it is joined to the rest of the round rod, is
ground down to its circular-ground final contour.. The circular-ground final
contour of the hard metal tool to be produced is that contour of the finished tool
that is to be produced by circular grinding. Then cutting, spiral cutting, and the
like are performed on the tool in subsequent methods. Since the end region
projecting from the workpiece spindle head can have a considerable length
depending on the tool, it is necessary to grip it at its free end, which is another
reason a very precise contour is required. Therefore in the inventive method
initially at least one steady rest is ground onto the free projecting end region.
Then, if the end region is supported by means of the at least one steady rest on
one or a plurality of steadies, a first end-face taper can be ground with the
required precision onto the end face of the round rod, that is, of its end region,
that faces the tailstock. The end-face taper is then fitted in a securely clamped
manner with a hollow center punch on a sleeve of the tailstock. The end region
is now again gripped at its two ends without it having been necessary to release
the first clamping in the workpiece spindle head. Circular grinding can again

be performed with the required precision on the already described
circular-ground final contour.
Then the thus finish-ground individual tool is cut off from the round rod;
the chuck of the workpiece spindle head, which to this point has remained
clamped, is released, and the round rod is moved forward a bit in the released
chuck in the direction of the tailstock, whereby another end region of the round
rod that is to be processed projects from the workpiece spindle head.
In the present context, the description of a "thus finish-ground individual
tool" is somewhat different from fmish-grinding in the sense of finish-cut as
opposed to rough-tinned. Nor does it mean that the hard metal tool to be
produced must now be ready for use. On the contrary, here the term
finish-ground merely means that the resulting hard metal tool is as finish-ground
in its first clamping as is the object of the circular grinding, that is, just to its
desired circular-ground final contour.
The advantages of the inventive method are comprised above all in that
multiple clamping is avoided. Thus re-chucking errors are avoided, and the
result is the best circular trueness of the run results and shape and position
tolerances relative to the shaft and cut part Despite higher acquisition costs for
the circular grinding machine, the costs for the individual workpiece are
reduced because the resulting tool is processed in a single machine from
unmachined part to rough-finished part or even finished pan. Furthermore,

through-times are reduced, and it is possible to react very rapidly to an order
for a specific hard metal tool because the desired end regions can be cut off of
the round rod in different lengths. Thus, finally, the stored inventory of
semi-finished products can be reduced because production is flexible and rapid.
One advantageous furthet development of the inventive method is
comprised in that during circular grinding of the end region of the round rod
that projects from the workpiece spindle head, the steady is retracted from the
steady rest. The steady acts primarily to grind with the greatest possible
precision the clamped end of the end region of the round rod that projects from
the workpiece spindle head and that faces the tailstock. On the other hand, the
grinding of the workpiece contour can occur without additional support from
steadies, This simplifies processing, and it is possible to attain with nothing
further a perfect surface of the circular-ground final contour.
In the case of high demands in terms of precision, even for thin round
rods, two steady rests can be ground axially spaced from one another on the end
region of the round rod In many cases, that is, with shorter hard metal tools,
only one steady rest will be adequate, however.
Another advantageous embodiment of the inventive method is comprised
in that the end region of the round rod that projects from the workpiece spindle
head is separated from the remaining round rod after circular grinding in that

with a single grinding wheel first with the round rod rotating a second end-face
taper is ground on the end face of the thus finished tool that feces the workpiece
spindle head and then after the grinding wheel has been retracted and amlly
displaced relative to the round rod a separating cut leaving only a central
connecting band is applied and finally after the rotational movement of the
round rod has ceased the separation process is concluded by grinding off the
connecting band.
Using this approach, the projecting end region of the round rod remains
joined to the rest of the round rod until the last possible moment, namely, via
the central connecting band. Thus two-sided clamping of the end region
without repeated re-chucking is possible until the very end, and processing
accuracy is further enhanced without additional complexity. Furthermore,
giinding can proceed on the rotating round rod for as long as possible, which is
advantageous for the thermal stress on the resulting tool.
When the finish-ground individual tool has been finally cut off, the
tailstock and/or the sleeve are then retracted from the resulting finished tool,
and it is held by a clamping unit. Once the separating process has concluded,
the clamping unit can remove the thus finished tool from the machine and
deposit it, further enhancing the efficiency of the method..
The known circular grinding techniques can be used for the most
important process of circular grinding in accordance with method step e) in

claim 1 Thus the circular grinding can occur for producing the tool contour
with a nanow grinding wheel in the rough grinding method and/or with a wide
grinding wheel in a pendulum grinding method
The inventive method can be performed both in a nearly manual
procedure and in a highly automated design. In the latter case, care must be
taken above all that the last rod piece to be processed is not gripped in the
chuck of the workpiece spindle head with an axial extension that is not long
enough. If this happens errors occur thar are due to poor trueness of the run as
a result of the gripping length being too short. Incomplete chucking can lead to
damage of the machine or even accidents if the proper care is not exercised. In
order to prevent this, in accordance with another embodiment of the inventive
method it is provided that the rest of the length of the round rod that remains
available for moving the round rod through the chuck of the workpiece spindle
head is checked at least during every chucking process and when it does not
meet a certain minimum remaining length a signal is given and/or the circular
grinding machine is stopped.
In this manner the greatest possible safety is provided for the method.
The invention also relates to a circular grinding machine for grinding
cylindrical starting bodies during the production of tools made of hard metal, in
particular for performing the method in accordance with any of claims 1
through 7

In accordance with claim 8, such an inventive machine is provided with
a machine bed, with a grinding table that can travel on the machine bed and on
which are arranged a workpiece spindle head and a tailstock, with a chuck on
the workpiece spindle head that enables a round rod acting as a starting material
to be moved through and chucked in different axial positions, with at least one
steady arranged in the region between the workpiece spindle head and the
tailstock and with a gripping unit ananged in the same region, whereby an end
region of the round rod that has been moved through the chuck of the workpiece
spindle head and securely clamped can additionally be held selectively by the
tailstock and/or the steady and/or the gripping unit, and with at least one
grinding spindle head with one or a plurality of grinding spindles and that can
be used to position one or a plurality of different grinding wheels at the round
rod.
Thus, in the inventive machine in accordance with claim 8 a number of
features cooperate such that the described advantages of the method can be
attained. In addition to the chuck of the workpiece spindle head, which permits
the round rod comprising hard metal to be moved through and gradually
clamped, the numerous devices for supporting the projecting end region of the
round rod are also necessary, that is, the tailstock, the one or a plurality of
steadies, and selectively also the gripping unit. The cooperation of all of these

individual parts is necessary in the prescribed sense so that the hard metal tools
can be produced economically and yet with great precision.
Fundamentally it is possible with the inventive circular grinding rnachine
to make due with a single grinding wheel if it is caused to engage the round rod
in an inclined position.
In this manner the end-face taper can be applied to the two ends of the
resulting tool, while when the grinding wheel and round rod are set parallel,
circular grinding can be performed to the desired final contour, However, it is
preferred when in accordance with one embodiment of the inventive circular
giinding machine a grinding spindle head is provided that carries two grinding
spindles and that can be pivoted about a pivot axis that is oriented perpendicular
to a plane in which lies the common axis for workpiece spindle head, round
rod, and tailstock.
In this manner two different giinding spindles can be brought into the
working position rapidly, each of these giinding spindles being able to cany a
plurality of grinding wheels.
Particularly preferred is the arrangement of a multiple giinding wheel in
which two or more giinding wheels of differing diameter, differing width,
and/or differing exterior contour are located immediately adjacent to one
another on a common driven axis.

In this manner a very specific grinding wheel that is specially embodied
for a specific procedure is employed without interference from the grinding
wheel located immediately adjacent thereto. For instance, of two adjacent
individual wheels, the one can be embodied for circular grinding in the rough
grinding method while the other, with a spherical grinding contour, grinds an
end-face taper in the optimum manner..
When there is a demand for greater numbers of these multiple grinding
wheels, it can also be advantageous that the different grinding wheels are
combined into a common grinding body. There is then an adapted shaped
grinding body for which only a single carrier body is required.
The inventive circular grinding machine can be advantageously provided
with CNC control, which then largely automates the entire grinding procedure.
Given the problems described in the foregoing because of which it is
necessary especially in a highly automated procedure to automatically monitor
the grinding procedure, in accordance with another advantageous embodiment,
allocated to the chuck of the workpiece spindle head is a sensor that checks the
remaining length of the round rod that is available for moving the round rod
through the chuck, at least during every chucking procedure, and when a
minimum lemarnmg length is not met provides a signal and/or stops the circular
grinding machine.

In such an embodiment a situation is avoided with certainty in which the
last remaining piece of a round tod that does not have a clamping length that is
long enough is ground, which can easily result in errors or even accidents.
In addition, in the inventive circular grinding machine, a tailstock with a
sleeve carrying a hollow center punch is used in an advantageous manner. A
hollow center punch is particularly well suited for centering the end-face taper
of a cylindrical part and securely receiving it.
The inventive method and the inventive circular grinding machine are
not only particularly well suited for grinding hard metal tools, but also for all
workpieces with similarly borne contours and problems.
The invention is explained in greater detail in the following using the
exemplary embodiments depicted in the figures. The following is illustrated in
the figures:
Fig. 1 is a view from above of a grinding machine for performing the
inventive method;
Fig 2 depicts the details of the grinding machine in accordance with
Fig. 1 during grinding of steady rests;
Fig. 3 is an illustration corresponding to Fig 2 depicting the grinding of
an end-face taper on the round rod;
Fig.. 4 illustrates all of the options for gripping the end region of the
round rod that projects from the workpiece spindle head.

Fig. 5 in addition illustrates the gripping unit that is employed when
separating the end region firom the round rod;
Figures 5a, 5b, and 5c illustrate the sequence of the separation
procedure after circular grinding of the resulting tool;
Fig. 6 schematically depicts the transition to circular grinding of the
following end region on the round rod;
Fig. 7 illustrates two different hard metal tools in the condition of their
circular-ground final contour.
Fig. 1 is the simplified view from above of a grinding machine for
performing the inventive method. The machine bed is labeled with the number
1, and in the front region a grinding table 2 is placed on it. The grinding table
2 can travel in the direction of the axis Z by means of a CNC control. Placed
on the grinding table 2 on the left-hand side is a workpiece spindle head 3 that
receives a chuck 4 that is driven rotationally by means of an electromotor (not
shown). The chuck 4 can be seen at the front of the workpiece spindle head 3..
It is used to grip the workpiece, in this case the round rod 6. The chuck 4 is
embodied such that the round rod 6 can be moved through the chuck and
securely clamped in the desired axial positions by means of the clamping jaws 5
(Figure 2). Positioned opposite the workpiece spindle head 3 on the grinding
table 2 is a tailstock 7 that receives a sleeve 8 that can travel in the axial
direction. The arrow 9 indicates the sleeve movement. The exterior end of the

sleeve 8 that faces the workpiece spindle head 3 is embodied as a hollow center
punch 10 and receives the end of the round rod that is ground to an end-face
taper.
Two steadies are labeled 11 and 12 and they can be positioned for
providing additional support at the end region of the round rod 6. The arrows
13 and 14 in Figure 2 indicate the direction of movement of the steadies 11 and
12.
The round rod 6, the workpiece spindle head 3, the chuck 4, the sleeve
8, and the tailstock 7 form a common center axis 15 that can also be called a
common functional axis,
Also in Fig. 1 there is a grinding spindle head 16 that carries a first
gtinding spindle 17 and a second grinding spindle 18. The first grinding
spindle 17 is fitted with a first grinding wheel 20 and the second grinding
spindle 18 is fitted with a second grinding wheel 21, The grinding spindle head
16 can be pivoted about a first pivot axis 19 that is oriented perpendicular to a
plane in which lies the common axis 15 of the workpiece spindle head 3, round
rod 6, and tailstock 7. As can be seen with nothing further from the illustration
in accordance with Fig. 1, the first grinding wheel 20 or the second grinding
wheel 21 can be selectively moved into the working position by pivoting the
grinding spindle head 16 about the pivot axis 19. Moreover, the grinding
spindle head 16 can also travel linearly in the direction of the X axis. The

travel in the direction of the X axis is also CNC-controlled The grinding
spindles 17 and 18 contain integrated electromotors that drive the grinding
wheels 20, 21 rotationally.
Additional details of the circular grinding machine illustrated in Fig. 1
are found in Figs. 2 through 4..
Thus in Fig. 2 the clamping jaws 5 of the chuck 4 can be seen that
clamp the round rod 6 for the grinding procedure. As stated, the round rod 6
can be moved through the chuck 4 and securely clamped in a selectable axial
position. When this happens, an end region 23 of the round rod 6 projects out
of the chuck 4 and the workpiece spindle head 3. The length of the end region
23 is approximately equal to the length of the hard metal tool to be produced
plus a certain clamping and processing length (see Fig. 5)..
Fig. 5 also schematically illustrates a gripping unit 22 whose clamping
parts 24 and 25 can grip and hold the end region 23 of the round rod from the
outside. The arrows 26, 27 indicate the movement of the clamping parts 24, 25.
Fig. 2 illustrates how the first grinding spindle 17 of the grinding
spindle head 16 travels into the working position. The first grinding wheel 20 is
illustrated enlarged. It has a base body 28 with a larger axial extension and a
narrow region 29 projecting radially therefrom, The narrow region 29 carries
the grinding coating 30 that has a cylindrical contour. The grinding wheel 20 is

for instance embodied as a diamond grinding wheel with a grinding coating that
is approx,. 5 mm high.
In contrast, in Fig. 3 the second grinding spindle 18 with the second
grinding wheel 21 is in the working position. The second grinding wheel 22
has a first individual wheel and a second individual wheel 32. The second
grinding wheel can be embodied as a multiple grinding wheel. However, the
two individual wheels 31 and 32 can also be called parts of a common grinding
body with a single base body.. The grinding coatings of the two individual
wheels 31 and 32 are labeled 33 and 34. The two individual wheels 31 and 32
have a different axial thickness and are both fitted with conical grinding
surfaces that have opposing inclines,,
In accordance with the illustration in Fig. 5, as well, the second grinding
spindle 18 with the second grinding wheel 21 is employed.
The other machine parts that are illustrated in Figs. 2 through 5 have the
previously mentioned reference numbers and are therefore not detailed
individually.
The grinding procedure to be performed on the grinding machine in
accordance with Figures 1 through 6 occurs in the following manner:
The starting material is the previously mentioned round rod 6 made of a
sintered hard metal. Such a round rod, which can have for instance a length of
300 to 400 mm, is moved through the chuck 4 of the workpiece spindle head 3

until an end region 23 (Fig. 2) of the desired length projects from the chuck 4.
In this position the clamping jaws 5 are moved against the round rod 6 so that
the latter is securely clamped.
Then the first grinding spindle 17 of the grinding spindle head 16 is
brought into the working position, Thus a first steady rest 35 is ground into the
end region 23 of the round rod 6 by means of the first grinding wheel 20 that is
located on the first grinding spindle 17 and that is rotatingly driven. Then the
first steady 11 is moved in the direction of the arrow 13 against the Hist steady
rest 35 so that the end region 23 is securely supported during furthet grinding
procedures.
When necessary, a second steady rest 36 or additional steady rests can
be ground into the end region 23 of the round rod 6. The second steady 12 is
provided for this, for instance. During this, the steady rest 36, which is
arranged closer to the chuck 4, is then ground first and then the steady rest 35 is
ground.
In accordance with the illustration in accordance with Fig. 3, both
steadies 11 and 12 are placed against the associated steady rests 35, 36. The
end region 23 is thus securely supported. Now the second grinding spindle 18
with the second grinding wheel 21 is brought into the working position, Its first
individual wheel 31 then grinds a first end-face taper 37 into the end face of the
round rod 6, that is, its end region 23, that faces the tailstock 7. The first

end-face taper 37 is dimensioned such that it fits into the hollow center punch
10 of the sleeve 8 that is displaceably arranged in the direction of the arrow 9 in
the tailstock 7.
Fig. 4 illustrates the condition in which the free end of the end region 23
with the first end-face tapei 37 is securely gripped in the hollow center punch
10 Located in the working position again is the first grinding spindle 17 of the
grinding spindle head 16, which is again positioned in the direction of the X
axis at the end region 23 CNC controlled. At the same time, the grinding table
2 travels CNC-conttolled in the direction of the Z axis. In this manner nearly
the entire length of the end region 23 is circular ground in the rough-grinding
procedure by means of the first grinding wheel 20. This means that this length
is ground in a single procedure of the grinding wheel 20 on the end region 23.
However, it is also possible to use a wider grinding wheel and to perform the
procedure in the pendulum grinding method. In this case, there are then a
plurality of radial positioning movements, and the longitudinal movement must
be repeated multiple times until grinding overmeasure 38 is carried off and the
desired surface condition of the end region 23 has been attained.
Fig, 4 illustrates a condition in which the steadies 11 and 12 are also
positioned against the end region 23 during this part of the procedure.
However, this is by no means required. The use of the steadies 11 and 12 is
primarily unavoidable when the first end-face taper 37 is being ground. In the

following procedures, work can also be performed in that the steadies ate then
retracted.
The procedure of circular grinding illustrated in Fig, 4 is by no means
limited solely to obtaining a continuously cylindrical contour of the desired
surface quality. On the contrary, in this method step the entire circular-ground
final contour of the resulting finished hard metal tool should be attained. That
is, depending on the final contour of the tool, partial regions can already be
ground out with cylindrical, tapered, or spherical contours in this stage of the
method in which the end region 23 is still situated on the round rod. All
contours that can be obtained by circular grinding are conceivable. This can
also occur in that a set of grinding wheels with different contours are employed.
This is not illustrated in Fig. 4, however
Figure 7 illustrates examples of such circular-ground final contours.
The end region 23 of the round rod 6 and thus the resulting hard metal
tool ate therefore thus finish ground. The term "finish grinding" here does not
mean finish grinding in the sense of smoothing as opposed to roughing, but
rather the most final stage that can be attained for the resulting tool by circular
grinding. Then cutting, spiral cutting, and the like must be performed in
separate methods. First, however, it is necessary to separate the thus
finish-ground tool from the round rod 6.

The procedure is explained using Figures 5 and 5 a through 5c. The
final region 23 of the round iod 6 is first still clamped at both ends, as
illustrated in Figure 4. One or a plurality of steadies can be positioned at the
end region 23; however, this is not required. Deviating from the illustration in
accordance with Figure 4, the second grinding spindle 18 is brought into the
working position in that the grinding spindle head 16 is pivoted about the pivot
axis 19. Now the second individual wheel 32 of the second grinding wheel 21,
which is a multiple grinding wheel and which has a larger diameter than the
first individual wheel 31, is employed. The rotating second individual wheel 32
is then positioned against the also rotating end region 23 of the round rod 6.
This first positioning procedure is then interrupted as soon as the second
individual wheel 32 has ground the second end-face taper 39 (Figure 5a).
Then the second grinding wheel 21 is retracted from the end region 23
of the round rod 6.. The round rod 6 and the second individual wheel 32 are
mutually offset axially relative to one another The offset is approximately the
thickness of the second individual wheel 32. Then the individual wheel 32 is
again positioned against the end region 23 of the round rod 6 and this time
effects a separating cut 40. The procedure is continued until the connection
between the remaining residual length of the round rod 6 and its end region 23
comprises only a narrow connecting band 41. Until this point the end region 23
of the round rod 6 was clamped at its two ends and driven to rotate (Figure 5b).

Then the rotational drive of the workpiece spindle head is stopped, and
the tailstock 7 with the sleeve 8 is retracted from the clamping position. The
end region 23 of the round rod 6 with the first end-face taper 37 is now free and
is enclosed and securely held by the clamping parts 24, 25 of the gripping unit
22 Further positioning of the second individual wheel 32 then continues the
separating process and the connecting band 41 is also ground off (Figure 5c).
The tool, which is finished in terms of circular grinding, is now separated from
the remainder of the round rod 6 and thus finished. The resulting hard metal
tool is held in the gripping unit 22 and is removed from the machine and
deposited by it (see Figure 5).
Then the round rod is again moved out of the chuck 4 a bit so that the
next end region 23 can be processed (Figure 6)..
Figure 7 illustrates two different hard metal tools in one stage as can be
attained with the inventive method and the inventive circular grinding machine.
The second end-face taper can be seen on the illustrated, thus finish-ground
tools at their one end. The original cylindrical contour of the round rod 6 i$
illustrated with the dashed lines, so that it can be seen how the desired
circulat-ground final contour was obtained solely by circular' grinding. The
figure makes it possible to see clearly that graduated cylindrical, tapered, or
spherical contours can be obtained with nothing further. The special aspect of
this is comprised in mat these numerous shapes were created, whereby at least

at the one end a single clamping of the round rod forming the starting material
was sufficient..
It should be remarked that the performance of the method is not limited
to the measures depicted in Figs. 1 through 5. It is even possible to make do
with a single grinding wheel for all of the procedures when it is possible to
position this grinding wheel in an inclined position against the round rod.
LIST OF REFERENCE NUMBERS
1 Machine bed
2 Grinding table
3 Workpiece spindle head
4 Chuck
5 Clamping jaws
6 Workpiece
7 Tailstock
8 Sleeve

9 Arrow (sleeve movement)
10 Hollow center punch
11 First steady
12 Second steady
13 Arrow (positioning movement of steady 11)
14 Anow (positioning movement of steady 12)

15 Common axis (functional axis)
16 Grinding spindle head
17 First grinding spindle
18 Second grinding spindle
19 Pivot axis of the grinding spindle head
20 First grinding wheel
21 Second grinding wheel
22 Gripping unit
23 End legion of 6
24 Clamping par t o f 2 2
25 Clamping part of 22
26 Airow
27 Airow
28 Base body
29 Narrow region
30 Grinding coating
31 First individual wheel
32 Second individual wheel
33 Grinding coating of 31
34 Grinding coating of 32
35 First steady rest

F-8756 Identifier: Erwin JUNKER
36 Second steady rest
37 First end-face taper
38 Grinding overmeasure
39 Second end-face taper
40 Separating cut
41 Connecting band

We Claim
1. Method for circular grinding during the production of toots made of hard
metal on a circular grinding machine that has a workpiece spindle,head
and a tailstock, whereby work commences using a round rod comprising a
starting material, characterized by the following method steps:
a) Gripping said round rod (6), whose length is a multiple of the
length of a single tool, in a chuck (4) of said workpiece spindle
head (3) that when said chuck (4) is released enables axial
displacement of said round rod (6), whereby an end region (23) of
said round rod (6) that projects out of said workpiece spindle head
(3) faces said tailstock (7);
b) Grinding at least one steady rest (35,36) on said end region (23) of
said round rod (6) that projects from said workpiece spindle head
(3) and placing the steady (11,12) on said steady rest (35,36);
c) Grinding a first end-face taper (37) on said end face of said round
rod (6) that faces said tailstock (7);
d) Secure-clamping fitting of said first end-face taper (37) with a
hollow center punch (10) that is located on a sleeve (8) of said
tailstock (7);
e) Circular grinding of said end region (23) of said round rod (6) that
projects from said workpiece spindle head (3) over a length that
corresponds to about the overall length of the individual tool up to
its circular-ground Final contour;
f) Cutting off the thus finish-ground individual tool from said round
rod (6);

g) Releasing said chuck (4) of said workpiece spindle head (3), which
to this point has remained clamped, moving said round rod (6) in
said workpiece spindle head (3) in the direction of said tailstock
(7), and then loading said chuck (4), whereby an additional end
region of said round rod (6), which end region is to be processed,
projects from said workpiece spindle head (3).
2. Method as claimed in claim 1, wherein during circular grinding of said end
region (23) of said round rod (6) that projects from said workpiece spindle
head (3), said steady (11,12) is retracted from said steady rest (35,36).
3. Method as claimed in claim 1 or 2, wherein two steady rests (35,36) are
ground axially spaced from one another on said end region (23) of said
round rod (6).
4. Method as claimed in any of claims 1 through 3, wherein said end region
(23) of said round rod (6) that projects from said workpiece spindle head
(3) is separated from the remaining round rod (6) after circular grinding in
that with a single grinding wheel (21) first with said round rod (6) rotating
a second end-face taper (39) is ground on the end face of the thus
finished tool that faces said workpiece spindle head (3) and then after
said grinding wheel (21) has been retracted and axially displaced relative
to said round rod (6) a separating cut (40) leaving only a central
connecting band (41) is applied and finally after the rotational movement
of said round rod (6) has ceased the separation process is concluded by
grinding off said connecting band (41).

5. Method as claimed in any of the preceding claims, wherein while the
finish-ground individual tool is cut off said tailstock (7) and/or said sleeve
(8) are retracted from the resulting finished tool, and it is held by a
clamping unit (22).
6. Method as claimed in any of the preceding claims, wherein the circular
grinding occurs for producing the tool contour with a narrow grinding
wheel in the rough grinding method and/or with a wide grinding wheel in
a pendulum grinding method.
7. Method as claimed in any of the preceding claims, wherein the rest of the
length of said round rod (6) that remains available for moving said round
rod (6) through said chuck (4) of said workpiece spindle head (3) is
checked at least during every chucking process and when it does not meet
a certain minimum remaining length a signal is given and/or said circular
grinding machine is stopped.
8. Circular grinding machine for grinding cylindrical starting bodies during the
production of tools made of hard metal, in particular for performing the
method in accordance with any of claims 1 through 7, with a machine bed
(1), with a grinding table (2) that can travel on said machine bed (1) and
on which are arranged a workpiece head (3) and a tailstock (7), with a
chuck (4) on said workpiece spindle heed (3) that enables a round rod (6)
acting as a starting material to be moved through and chucked in different
axial positions, with at least one steady (11,12) arranged in the region
between said workpiece spindle head (3) and said tailstock (7) and with a
gripping unit (22) arranged in the same region, whereby an end region

(23) of said round rod (6) that has been moved through said chuck (4) of
said workpiece spindle head (3) and securely clamped can additionally be
held selectively by said tailstock (7) and/or said steady (11,12) and/or said
gripping unit (22), and said gripping unit (22) is embodied such that it can
remove from the machine and deposit the thus finished tool that is no longer
rotating, and with at least one grinding spindle head (16) with one or a
plurality of grinding spindles (17,18) that can be used to position one or a
plurality of different grinding wheels (20,21) at the round rod (6).
9. Circular grinding machine as claimed in claim 8, comprising

a grinding spindle head (16) that carries two grinding spindles (17,18)
and that can be pivoted about a pivot axis (19) that is oriented
perpendicular to a plane in which lies the common axis (15) for
workpiece spindle head (3), round rod (6), and tailstock (7).
10. Circular grinding machine as claimed in with claim 8 or 9, comprising the
arrangement of a multiple grinding wheel (21) in which two or more individual
grinding wheels (31,32) of differing diameter, differing width, and/or differing
exterior contour are located immediately adjacent to one another on a common
driven axis.
11. Circular grinding machine as claimed in claim 10, wherein said individual
grinding wheels are combined into a common grinding body.
12. Circular grinding machine as claimed in any of the preceding claims, wherein
said machine is provided with a CNC control.

13. Circular grinding machine as claimed in any of the preceding claims, wherein
allocated to said chuck (4) of said workpiece spindle head (3) is a sensor that
checks the remaining length of said round rod (6) that is available for moving
said round rod (6) through said chuck (I), at least during every chucking
procedure, and when a minimum remaining length is not met provides a signal
and/or stops said circular grinding machine.
14. Circular grinding machine as claimed in any of the preceding claims, wherein
said tailstock (7) has a sleeve (8) carrying a hollow center punch (10).

Method for circular grinding during the production of tools made of hard metal
on a circular grinding machine that has a workpiece spindle head and a tallstock,
whereby work commences using a round tod comprising a starting material,
characterized by the following method steps:
a) Gripping said round rod (6), whose length is a multiple of the
length of a single tool, in a chuck (4) of said workpiece spindle
head (3) that when said chuck (4) is released enables axial
displacement of said round rod (6), whereby an end region (23) of
said round rod (6) that projects out of said workpiece spindle head
(3) faces said tailstock (7);
b) Grinding at least one steady rest (35,36) on said end region (23) of
said round rod (6) that projects from said workpiece spindle head
(3) and placing the steady (11,12) on said steady rest (35,36);
c) Grinding a first end-face taper (37) on said end face of said round
rod (6) that faces said tailstock (7);
d) Secure-clamping fitting of said first end-face taper (37) with a
hollow center punch (10) that is located on a sleeve (8) of said
tailstock (7);
e) Circular grinding of said end region (23) of said round rod (6) that
projects from said workpiece spindle head (3) over a length that
corresponds to about the overall length of the individual tool up to
its circular-ground final contour;
f) Cutting off the thus finish-ground individual tool from said round
rod (6);

g) Releasing said chuck (4) of said workpiece spindle head (3), which

to this point has remained clamped, moving said round rod (6) in
said workpiece spindle head (3) in the direction of said tailstock
(7), and then loading said chuck (4), whereby an additional end
region of said round rod (6), which end region is to be processed,
projects from said workpiece spindle head (3).