U.S. patent application number 14/918124 was filed with the patent office on 2016-09-22 for tool for machining workpieces.
The applicant listed for this patent is Kennametal Inc.. Invention is credited to Norbert DENKS, Sebastian FOETTINGER, Markus HEINLOTH, Jochen KURZ, F.H. Erich LILL, Guenter SPONSEL.
Application Number | 20160271709 14/918124 |
Document ID | / |
Family ID | 55637818 |
Filed Date | 2016-09-22 |
United States Patent
Application |
20160271709 |
Kind Code |
A9 |
DENKS; Norbert ; et
al. |
September 22, 2016 |
TOOL FOR MACHINING WORKPIECES
Abstract
A tool (2) for machining workpieces, comprising a carrier (4)
rotating in an axial direction (A) during operation, and further
comprising multiple cutting segments (6), which are fastened to the
carrier (4) in a radial direction (R), characterized in that at
least one hydraulic clamping unit (21) is attached to the carrier
(4) for clamping at least one of the cutting segments (6) to the
carrier (4).
Inventors: |
DENKS; Norbert; (Wlndsbach,
DE) ; FOETTINGER; Sebastian; (Gunzenhausen, DE)
; HEINLOTH; Markus; (Postbauer-Heng, DE) ; KURZ;
Jochen; (Markgroningen, DE) ; LILL; F.H. Erich;
(Schwaig, DE) ; SPONSEL; Guenter; (Steinsfeld,
DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Kennametal Inc. |
Latrobe |
PA |
US |
|
|
Prior
Publication: |
|
Document Identifier |
Publication Date |
|
US 20160107250 A1 |
April 21, 2016 |
|
|
Family ID: |
55637818 |
Appl. No.: |
14/918124 |
Filed: |
October 20, 2015 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B23D 2043/063 20130101;
B23D 43/06 20130101; B23C 5/2234 20130101; B23C 2270/025
20130101 |
International
Class: |
B23D 43/06 20060101
B23D043/06 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 15, 2014 |
DE |
1020142209331 |
Claims
1. A tool (2) for machining workpieces, comprising a carrier (4)
rotating in an axial direction (A) during operation, and further
comprising multiple cutting segments (6), which are fastened to the
carrier (4) in a radial direction (R), characterized in that at
least one hydraulic clamping unit (21) is attached to the carrier
(4) for clamping at least one of the cutting segments (6) to the
carrier (4).
2. The tool (2) according to the preceding claim, characterized in
that the cutting segments (4) can be reversibly fixed, by clamping,
to the carrier (4) jointly by means of a clamping ring (12).
3. The tool (2) according to claim 1, characterized in that the
carrier (4) and the clamping ring (12) are spaced apart from one
another in the axial direction (A) and form a clamping groove (14)
in which the cutting segments (6) are seated.
4. The tool (2) according to claim 2, characterized in that the
clamping ring (12) can be displaced in the axial direction (A)
relative to the carrier (4) for this purpose by means of the
hydraulic clamping unit (21).
5. The tool (2) according to claim 2, characterized in that each of
the cutting segments (6) has a segment base (8), which is seated in
the clamping groove (14), and at least one of the parts, selected
from the parts that are the carrier (4) and clamping ring (12), has
a circumferential collar (22), which tapers the clamping groove
(14) on a radially external section and surrounds the segment base
(8).
6. The tool (2) according to claim 5, characterized in that the
collar (22) has an oblique gripping surface (26) which points
inwardly with respect to the clamping groove (14) and engages an
outwardly pointing, oblique shoulder surface (28) of the segment
base (8).
7. The tool (2) according to claim 2, characterized in that a
transformation element (16), which is designed to transform a
radial movement generated by the hydraulic clamping unit (21) into
an axial movement of the clamping ring (12), is arranged on the
carrier (4).
8. The tool (2) according to claim 7, characterized in that the
transformation element has a clamping wedge (16), which can be
displaced in the radial direction (R) by means of the hydraulic
clamping unit (21) and, with a wedge surface (18), engages a wedge
bearing surface (20) of the clamping ring (12) so as to axially
displace the same.
9. The tool (2) according to claim 2, characterized by a pull-out
limiter (36), which specifies a maximum axial pull-out (A.sub.max)
of the clamping ring (12) during detachment of the cutting segments
(6).
10. The tool (2) according to claim 1, characterized by a clamping
element (30), which is used to generate hydraulic pressure by means
of the hydraulic clamping unit (21) and, for this purpose, can be
toggled between a clamping position and a release position, so as
to clamp and release the cutting segments (6).
11. The tool (2) according to claim 10, characterized by multiple
hydraulic clamping units (21), which can be actuated jointly by
means of the clamping element (30).
12. The tool (2) according to claim 10, characterized in that the
clamping element (30) is formed as a rotating annulus, which can be
toggled between the clamping position and the release position by a
rotation.
13. The tool (2) according to claim 10, characterized in that in
order to toggle between the clamping position and the release
position, at least one eccentric actuating element (34) is attached
on the clamping element (30) so as to actuate the hydraulic
clamping unit (21) when toggling into the clamping position.
14. The tool (2) according to claim 1, characterized in that at
least one slot nut (38) is fastened to the carrier (4) for each of
the cutting segments (6) so as to position the cutting segments (6)
in the circumferential direction (U).
15. The tool (2) according to claim 1, characterized in that the
hydraulic clamping unit (21) is a self-contained assembly, which is
mounted to the carrier (4).
Description
RELATED APPLICATION DATA
[0001] The present application claims priority pursuant to 35
U.S.C. .sctn. 119(a) to German Patent Application Number
1020142209331 filed Oct. 21, 2014 which is incorporated herein by
reference in its entirety.
FIELD
[0002] The invention relates to a tool for machining workpieces,
comprising a carrier rotating in an axial direction during
operation, and further comprising multiple cutting segments, which
are fastened to the carrier in the radial direction.
BACKGROUND
[0003] Such a tool is known from EP 2 136 951 B1 and is used, for
example, for turning-turn broaching when manufacturing crankshafts.
The cutting segments of the tool are fastened to the carrier by
means of multiple bolts. A number of cassettes are, in turn,
attached at each cutting segment to accommodate the inserts. The
bolts engage the carrier radially in order to fasten each of the
cutting segments to the carrier. In addition, it is possible to
secure the cutting segments in the axial direction at clamping
points.
SUMMARY
[0004] The object of the invention is to improve, and in particlar
to simplify, the fastening and replacement of cutting segments on
the tool.
[0005] The object is achieved according to the invention by a tool
having the features according to claim 1. Advantageous embodiments,
refinements, and variants are the subject matter of the dependent
claims.
[0006] The tool is designed for machining workpieces and
particularly suitable for turning-turn broaching, for example for
manufacturing crankshafts. The tool is in particular a rotating
tool and has a carrier, which rotates in an axial direction during
operation. The carrier thus has a rotational axis. In addition, it
is possible to attach the tool to a machine tool by means of the
carrier. Furthermore, the tool has multiple cutting segments, each
of which is fastened to the carrier in the radial direction and
around the same in a circumferential direction with respect to the
axial direction. In doing so, the radial direction is understood to
be each direction that is perpendicular to the axial direction. The
cutting segments are formed, for example, as a single piece and
provided with suitable cutting edges. Preferably, the cutting
segments are designed in multiple pieces such that a number of
cutting elements, particularly inserts, can be mounted on one
cutting segment. To this end, a particular cutting segment has
suitable mounts in which the cutting elements can be fastened. The
mounts in this case are designed as insert seats integrated into
the carrier or else as separate cassettes, which can be fastened,
in turn, to the carrier.
[0007] In addition, there is at least one hydraulic clamping unit
attached to the carrier in order to clamp at least one of the
cutting segments to the carrier. To this end, the hydraulic
clamping unit in particular includes a hydraulic fluid, which is
used to actuate the clamping unit so as to generate hydraulic
pressure. The hydraulic pressure, in turn, is translated into
clamping force, which is used to hydraulically-mechanically clamp
the at least one cutting segment to the carrier.
[0008] The advantages achieved with the invention are in particular
that especially secure and robust locking of the cutting segments
can be achieved by means of the hydraulic clamping unit in a
particularly simple manner and with merely low complexity.
[0009] The fixing, by clamping, is advantageously not separate for
each of the cutting segments but occurs instead jointly by means of
a clamping ring. Thus, in a preferred embodiment, the cutting
segments can be reversibly fixed to the carrier, by clamping,
jointly by means of a clamping ring. Compared to separate clamping
of each cutting segment, this makes the handling of the tool
significantly simpler. In doing so, a clamping force is exerted
onto multiple, or particularly all, of the cutting segments by the
clamping ring during clamping. In addition, the clamping is
advantageously reversible, wherein it is possible to simultaneously
release all by means of the clamping ring of the cutting segments
that are fixed, by clamping, by the clamping ring. The clamping
ring in particular extends in a circumferential direction in the
axial direction of the tool, similarly to the carrier. The ring can
in particular be rotated in the axial direction concentrically with
respect to the rotational axis of the carrier.
[0010] Expediently, the carrier and the clamping ring are spaced
apart from one another in the axial direction and form a clamping
groove in which the cutting segments are seated. During fixing by
clamping, the cutting segments are held positively in the clamping
groove in the axial direction by the carrier and by the clamping
ring. In addition, the cutting segments are clamped into the
clamping groove due to a clamping force acting in the axial
direction.
[0011] In a suitable refinement, the clamping ring can be displaced
in the axial direction relative to the carrier by means of the
hydraulic clamping unit. In this way, it is advantageously possible
to press the respective cutting segment against the carrier in the
axial direction, i.e. to generate a clamping force in the axial
direction, that is [to generate] an axial force and thus clamp the
cutting segment to the carrier in the axial direction. This will in
particular also prevent slippage of the cutting segment in the
axial direction during operation. The distance between the clamping
ring and the carrier in the axial direction can be set, in
particular by means of the hydraulic clamping unit. By displacing
the clamping ring, it is then possible to either fix, by clamping,
or release the cutting segments.
[0012] Each of the cutting segments preferably has a segment base,
which is seated in the clamping groove. At least one of the parts,
selected from the parts that are the carrier and clamping ring, has
a circumferential collar, which tapers the clamping groove on a
radially external section and surrounds the segment base. In this
manner, form locking also advantageously occurs in the radial
direction, and the cutting segments are reliably secured against
being moved during operation in the radial direction, for example
due to centrifugal forces. The clamping groove in particular also
forms an annular chamber, having an access slot which is located
externally in the radial direction and from which the respective
cutting segments protrude. The respective segment base of the
cutting segment is seated in the clamping groove and engages the
collar. A circumferential collar is formed at least either on the
carrier or on the clamping ring. In a preferred variant, a collar
is arranged both on the carrier and on the clamping ring. In the
latter case, the segment base is then in particular surrounded by
the collar on both sides and held in the clamping groove in an
especially stable manner.
[0013] In a cross-section that is longitudinal with respect to the
axial direction, the sections of the carrier and of the clamping
ring which are spaced apart from one another in the axial direction
each form an extension or else an arm extending in the radial
direction, to the respective end of which located externally in the
radial direction the collar is attached.
[0014] In an advantageous refinement, the collar has an oblique
gripping surface, which points inwardly with respect to the
clamping groove and engages an outwardly pointing, oblique shoulder
surface of the segment base. As a result of this embodiment, it is
advantageously possible to translate the axial movement of the
clamping ring during the displacement in the axial direction into a
radial movement of the cutting segments. In doing so, the gripping
surface and the shoulder surface cooperate in particular in the
manner of a bevel gear. The clamping force generated when clamping
the clamping ring in the axial direction, which is also referred to
as the axial force, is at least partially converted into a radial
force acting radially inward by way of the oblique arrangement of
the gripping and shoulder surfaces. In this manner, the segment
base and the corresponding cutting segment are pulled toward the
center of the tool. An oblique surface, here and hereinafter, is
understood to mean in particular that the corresponding surface is
inclined with respect to the axial direction. In particular, the
gripping surface of the collar is formed in the shape of a
truncated cone sheath. The shoulder surface of the segment base is
preferably formed complementary thereto and in the manner of a
segment of a truncated cone sheath.
[0015] So as to axially displace the clamping ring, a
transformation element is expediently arranged on the carrier,
which converts a radial movement generated by the clamping unit
into an axial movement of the clamping ring. The hydraulic clamping
unit thus preferably generates an actuating movement of a component
in the radial direction, or at least not in the axial direction,
which is converted into the desired axial movement of the clamping
ring by means of the transformation element. This enables a compact
design, since the carrier of such a tool is typically disk-shaped
having only a small expansion in the axial direction. The radial
expansion is typically a multiple of the expansion in the axial
direction.
[0016] In a preferred embodiment, the transformation element is
formed as a clamping wedge, which can be displaced in the radial
direction by means of the hydraulic clamping unit. The clamping
wedge has a wedge surface, by means of which said clamping wedge
engages a wedge bearing surface of the clamping ring, particularly
during clamping. The wedge surface and the wedge bearing surface
have an oblique design, so that, as previously described in
connection with the collar and the segment base, a radial force
acting on the clamping wedge in the radial direction can be
converted into an axial force acting in the axial direction. This
force is then used to displace the clamping ring.
[0017] When the cutting segments are being clamped, the radial
force acting on the clamping wedge is in particular directed to the
outside in the radial direction. In doing so, the clamping wedge is
acted on by hydraulic pressure generated by the hydraulic clamping
unit. In general, a pressure ram movable in a cavity is in
particular arranged in the hydraulic clamping unit. The pressure
ram is fixedly connected to the transformation element, in
particular to the clamping part, and can be moved, which is to say
can be displaced, by way of the hydraulic fluid present in the
clamping unit. Since the tool typically has a significantly larger
expansion in the radial direction than in the axial direction, a
significantly larger stroke is possible, and thus a particularly
suitable clamping force can be generated, when displacing the
clamping wedge in the radial direction.
[0018] So as to release the cutting segments, the hydraulic
pressure is removed from the transformation element, in particular
the clamping wedge, by means of the hydraulic clamping unit, so
that the element, or the wedge, can be moved back into the opposite
direction. In particular, the transformation element, in particular
the clamping wedge, can be moved toward the inside in the radial
direction during the release and is pulled or pressed toward the
center of the tool, for example, by means of a return spring.
[0019] So as to prevent the clamping ring from falling off the
tool, particularly in the release position of the clamping element,
an pull-out limiter is attached to the tool. This pull-out limiter
specifies a maximum axial pull-out of the tension disk during
release of the cutting segments. Measured in the axial direction,
this axial pull-out is selected in particular at least large enough
such that a respective cutting segment can be removed from the
clamping groove in the radial direction in the release position.
Furthermore, the pull-out limiter suitably has an oblique contact
surface facing the clamping ring, which is designed in particular
similarly to the clamping surface of the clamping wedge and which
rests against the wedge bearing surface of the clamping ring at
maximum pull-out. In order to implement particularly effective
pull-out protection, the pull-out limiter is expediently designed
in the shape of a ring.
[0020] So as to generate hydraulic pressure by means of a hydraulic
clamping unit, the tool preferably has a clamping element. The
hydraulic clamping unit actuates said clamping element in order to
clamp the cutting segment. To this end, the clamping element can be
toggled between a clamping position and a release position so as to
clamp and release the cutting segments. In doing so, a number of
pressure pistons in the clamping unit are pressed in by means of
the clamping element such that they initially reduce the cavity
filled with the hydraulic fluid and, in this manner, the pressure
pistons is driven out of the cavity.
[0021] In a suitable variant, the tool comprises multiple hydraulic
clamping units, which can be jointly actuated by means of the
clamping element, whereby, in turn, the handling and operation of
the tool are significantly simplified. Preferably, at least one
hydraulic clamping unit is attached to the carrier for each cutting
segment, and all these hydraulic clamping units are jointly
actuated by means of the clamping element, such that clamping of
all cutting segments is possible in an especially simple manner.
Likewise, the clamping is reversible by releasing the clamping
element, and thus all cutting segments can be released
simultaneously.
[0022] In a further suitable embodiment, the clamping element is
designed as a rotating annulus, which can be toggled between the
clamping position and the release position through rotation. The
rotating annulus is rotatably mounted on the carrier. In
particular, it can be rotated around the rotational axis and thus
in the axial direction. Rotating into the clamping position then
results in clamping of the cutting segments to the carrier, while
rotating into the release position correspondingly results in
release of the cutting segments. The rotating annulus is in
particular designed as a ring and extends in the circumferential
direction in the axial direction of the tool, similarly to the
clamping ring. The rotation in order to toggle between the clamping
position and the release position takes place accordingly in the
circumferential direction in the axial direction. For rotation, the
rotating annulus is in particular accessible in the axial direction
and is, for example, operated manually or by means of a suitable
accessory.
[0023] In order to toggle between the clamping position and the
release position, preferably at least one eccentric actuating
element is attached to the clamping element. Said actuating element
is used to actuate the hydraulic clamping unit when toggling into
the clamping position. When using multiple hydraulic clamping
units, an eccentric actuating element is attached to the clamping
element particularly for each of these clamping units. Especially
in the case of a clamping element designed as a rotating annulus,
during rotation of the same a translational motion of the eccentric
actuating element in the circumferential direction, and thus a
relative movement with respect to the hydraulic clamping unit, take
place, so that the clamping unit is actuated in the aforementioned
manner. During rotation of the rotating annulus, i.e. during
rotation relative to the hydraulic clamping unit, the eccentric
actuating element then acts upon the pressure pistons of the
clamping unit. The eccentric actuating element may also be designed
as a bulge or recess extending in the radial direction, for example
one comprising protuberances. For example, the eccentric actuating
element is integrally molded to the rotating annulus as a
wedge-shaped step and attached to the rotating annulus pointing to
the outside in the radial direction.
[0024] So as to attach the cutting segments, they are initially
arranged in the release position distributed around the periphery
of the carrier. In order to achieve, in particular, suitable
positioning and distribution in the circumferential direction, at
least one slot nut is fastened to the carrier for each of the
cutting segments. Said slot nut is, for example, fixedly screwed to
the carrier and forms a bearing contour for the corresponding
cutting segment. Expediently, the respective cutting segment has a
recess that is adapted to the slot nut, in which the slot nut is
positively seated when positioned correctly.
[0025] So as to enable particularly simple replacement of the
hydraulic clamping unit in the event the same should become damaged
or fail, the clamping unit is designed as a self-contained
assembly, which is mounted to the carrier. The design of the
self-contained assembly additionally advantageously ensures that no
hydraulic fluid inadvertently leaks from the clamping unit and
contaminates the tool.
[0026] In an especially advantageous variant, one or more of the
aforementioned aspects are combined with an embodiment of a tool,
as it is described in application DE 10 2014 106 516.6 of the
applicant, which is unpublished as of the time of application. A
tool for turning-turn broaching of workpieces is likewise described
therein, comprising a carrier to which multiple cutting segments
comprising hydraulic clamping units can be fastened. A clamping
bolt is described therein as a clamping element, which actuates the
hydraulic clamping unit. The clamping bolt in this case presses
against one or more pressure pistons of the hydraulic clamping
unit. This actuating mechanism described in DE 10 2014 106 516.6
for the hydraulic clamping unit by means of the clamping bolt is
combined with the aforementioned clamping by means of the clamping
ring according to a first variant.
[0027] Furthermore, DE 10 2014 106 516.6 describes tension bolts
for clamping the cutting segments in the radial direction, which
engage the cutting segments and which clamp the cutting segments
against the carrier in the radial direction when the hydraulic
clamping unit is actuated. According to a second variant, said
clamping mechanism having the tension bolts is combined with the
joint actuation of multiple hydraulic clamping units described
herein by means of a shared clamping element, particularly by means
of a rotating annulus. Reference is made in this regard to the
disclosure of DE 10 2014 106 516.6, which is hereby also included
in the present application.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] An exemplary embodiment of the invention is described in
greater detail hereafter based on a drawing. The following is shown
schematically:
[0029] FIG. 1 shows a tool in a side sectional view;
[0030] FIG. 2 shows a detail of the view according to FIG. 1;
and
[0031] FIG. 3 shows the tool according to FIG. 1 in a front
view.
DETAILED DESCRIPTION
[0032] FIGS. 1 and 2 show the longitudinal sectional view along an
axial direction A of a tool 2, comprising a radially extending
carrier 4, that is in the radial direction R, which is
annular-shaped here and can be fastened to a machine tool, which is
not shown in greater detail. Multiple cutting segments 6 are
fastened on the outside of the carrier 4 in the radial direction R.
They are used in particular for accommodating the inserts, which
are not shown in more detail here. FIG. 2 shows an enlarged detail
of FIG. 1, which is identified there by a dotted rectangle. FIG. 3
shows the tool 2 in a front view. The tool 2 is a turning-turn
broaching tool, which rotates around a rotational axis in the axial
direction A during operation. The entire tool 2 is preferably
designed in the manner of a disk. The expansion thereof in the
radial direction R is a multiple, for example at least 5 times the
expansion in the axial direction A.
[0033] The cutting segments 6 each have a segment base 8 on the
interior in the radial direction R, comprising two shoulders 10
here, which are arranged on opposing sides of the respective
cutting segment 6 in the axial direction A. For fixing, by
clamping, the cutting segment 6, the tool 2 comprises a clamping
ring 12, which extends in a circumferential direction U in the
axial direction A, just as the carrier 4. FIGS. 1 and 2 show the
clamping ring 12 in the clamping position. The segment base 8 is
clamped in a clamping groove 14, which is formed by the clamping
ring 12 and the carrier 4. The clamping ring 12 and the carrier 4
have extensions 15 pointing toward the outside in the radial
direction R, which are spaced apart from one another by a distance
A1.
[0034] The clamping ring 12 exerts an axial force K1, which is also
referred to as the clamping force, in the axial direction A, which
is used to hold the cutting segments 6. This axial force K1 is
generated, in particular, by a clamping wedge 16, which can be
displaced in the radial direction R. To this end, said clamping
wedge 16 has a wedge surface 18, which is obliquely inclined with
respect to the axial direction A and presses against a wedge
bearing surface 20 of the clamping ring 12. For direct generation
of the axial force K1, a number of hydraulic clamping units 21 are
attached to the carrier 4. They can be used to generate a radial
force K2 acting outwardly in the radial direction R by way of
hydraulic fluid, which is not shown in more detail here, with
radial force K2 being usable to displace the clamping wedge 16 in
the radial direction R. Said radial force K2 is then at least
partially converted into the axial force K1 as a result of the
cooperation between the wedge surface 16 and the wedge bearing
surface 18.
[0035] In the exemplary embodiment shown here, the radial
extensions 15 of the clamping ring 12 and of the carrier 4 each
transition into a collar 22, which tapers the clamping groove 14
toward the exterior in the radial direction R and, in this manner,
forms an access slot 24 on the periphery of the tool, which can be
used to access the clamping groove 14. In addition, the collars
each comprise a gripping surface 26 pointing toward the clamping
groove 14 and surround the segment base 8 such that said gripping
surfaces 26 rest against outwardly pointing shoulder surfaces 28 of
the shoulders 10 of the cutting segment 6. Similarly to the
aforementioned translation of the radial force K2 into the axial
force K1, a partial translation of the axial force K1 into an
inwardly directed radial force K3 in the radial direction R occurs
in this manner. This results, in particular, in inward pulling of
the cutting segment 6. It is particularly apparent from FIG. 2 that
the respective collars 22 of the extensions 15 surround the segment
base 8 in the manner of tongs and, in doing so, clamp the base in
the axial direction A as well as in the radial direction R.
[0036] So as to bring the clamping wedge 16 into the clamping
position, the tool 2 comprises a clamping element 30, which is
designed as a rotating annulus here, which is used to actuate the
hydraulic clamping unit 21. To this end, the clamping element 30
has an eccentric actuating element 34 in the exemplary embodiment
shown here, which is implemented as a step here. Said step is
pushed into the clamping unit 21 during rotation such that a number
of pressure pistons, which are not shown in more detail, are
operated in order to displace hydraulic fluid present in the
hydraulic clamping unit 21, whereby, in turn, a pressure piston,
which is likewise not shown here, is driven out, which ultimately
pushes the clamping wedge 16 outward.
[0037] For release, the clamping element 30 is transferred into a
release position, whereby the hydraulic pressure on the clamping
wedge 16 is reduced, and the same can be displaced inwardly in the
radial direction R. The clamping wedge 16 is automatically pushed
back, for example, by means of a return spring, which is not shown
in more detail here. Due to the pushed-back clamping wedge 16, it
is then possible to enlarge the distance A1 between the clamping
ring 12 and the carrier 4 such that the cutting segments 6 can be
removed from the clamping groove 14. So as to prevent the clamping
ring 12 from falling off the tool 2 while doing so, a pull-out
protection device 36 is arranged additionally in the axial
direction A with respect to the carrier 4, the pull-out protection
device being designed in the shape of a ring here and preventing
displacement of the clamping ring 12 beyond a maximum distance
A.sub.max. This distance is suitably at least the sum of the
distance A1 and the width of the shoulders 10 in the axial
direction A.
[0038] So as to position the cutting segments 6 correctly in the
circumferential direction U with respect to the carrier 4 during
insertion, slot nuts 38 are additionally screwed onto the carrier
4, onto which a respective cutting segment 6 can be placed,
particularly in the radial direction R. A suitable recess, in which
the slot nut 38 is seated when positioned correctly, is introduced
for this purpose into the cutting segment 6 in a manner that is not
shown in more detail here.
* * * * *