U.S. patent application number 10/495321 was filed with the patent office on 2005-04-21 for cutting tool for breaking mineral and artificial materials.
Invention is credited to Levankovsky, Igor Anatolievich.
Application Number | 20050082899 10/495321 |
Document ID | / |
Family ID | 20254204 |
Filed Date | 2005-04-21 |
United States Patent
Application |
20050082899 |
Kind Code |
A1 |
Levankovsky, Igor
Anatolievich |
April 21, 2005 |
Cutting tool for breaking mineral and artificial materials
Abstract
The invention relates to the mining industry, in particular to a
cutting tool for breaking mineral and artificial materials. The
inventive tool comprises a working head provided with a hard-alloy
insert on one end thereof and a three-part stem on the other end. A
clamping sleeve made of elastic material is arranged on the second
part of the stem and provided with a slopping element in order to
prevent said sleeve from the displacement thereof longitudinally
with respect to the stem A protective element provided with a
through hole, in which the first part of the stem can be
accommodated, is disposed at a distance ranging from 0.6 to 0.85 of
the length of the clamping sleeve with respect to the end of said
sleeve oriented towards the working head along the longitudinal
symmetrical axis of the tool, the diameter of the first part of the
stem is larger than the diameter of the third part thereof. Said
invention makes it possible to improve the operating reliability of
the tool by reducing the deformation of the clamping sleeve by the
protective element by shaping said clamping sleeve in such a way
that it is conical.
Inventors: |
Levankovsky, Igor Anatolievich;
(Moscow, RU) |
Correspondence
Address: |
Merchant & Gould
Intellectual Property Law Firm
3200 Ids Center
80 South Eighth Street
Minneapolis
MN
55402-2215
US
|
Family ID: |
20254204 |
Appl. No.: |
10/495321 |
Filed: |
May 11, 2004 |
PCT Filed: |
October 31, 2002 |
PCT NO: |
PCT/RU02/00476 |
Current U.S.
Class: |
299/107 ;
299/104 |
Current CPC
Class: |
E21C 35/197
20130101 |
Class at
Publication: |
299/107 ;
299/104 |
International
Class: |
E21C 025/10 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 12, 2001 |
RU |
2001130335 |
Claims
1. A cutting tool for breaking mineral and artificial materials,
adapted for installation with the possibility for free rotation in
a channel of a support secured on an actuator, the tool having the
form of a body of revolution with a longitudinal axis of symmetry
and comprising a working head, an insert made of a hard-alloy
material and secured to one end of the working head, a stem
connected to the other end of the working head and comprising a
first part arranged on one end of the stem from the side of the
working head, a second part adjacent the first part and having a
diameter less than the diameter of the first part, and a third part
adjacent the second part, positioned on the other end of the stem
and having a diameter that is not less than the diameter of the
second part, a split clamping sleeve made of an elastic material,
arranged on at least the second part of the stem and having a
stopping element serving to fix it against movement along the
longitudinal axis of symmetry of the tool relative to the stem, a
protective element having a through axial hole with a diameter
exceeding the diameter of the first part of the stem and mounted on
the clamping sleeve with the possibility for axial movement along
the sleeve for positioning it on the first part of the stem during
the installation of the cutting tool in the channel of the support,
characterized in that the protective element is disposed at a
distance ranging from 0.6 to 0.85 of the length of the clamping
sleeve with respect to the end of the sleeve oriented towards the
working head along the longitudinal axis of symmetry of the tool,
wherein the diameter of the first part of the stem is greater than
the diameter of the third part thereof.
2. The tool according to claim 1, characterized in that the
diameter of the through hole in the protective element exceeds the
diameter of the channel of the support.
3. The tool according to claim 1, characterized in that the
protective element is made in the form of a flat washer.
4. The tool according to claim 1, characterized in that the
protective element is made in the form of a washer having a
U-shaped form in cross section.
5. The tool according to claim 1, characterized in that the
protective element is made in the form of a disk spring washer.
6. The tool according to claim 3, characterized in that the washer
is provided with an annular projection positioned along a through
axial hole of the washer, facing the third part of the stem and
adapted for arrangement in a corresponding input aperture of the
channel of the support of the tool.
7. The tool according to claim 1, characterized in that the
clamping sleeve is arranged on the second and third parts of the
stem, and its length along the longitudinal axis of symmetry of the
tool exceeds the sum length of the second and third parts of the
stem along that axis.
8. The tool according to claim 7, characterized in that the
stopping element is made in the form of at least one projection
positioned on an inner surface of the clamping sleeve, while the
second part of the stem has an annular recess for the arrangement
of that projection.
9. The tool according to claim 8, characterized in that the
stopping element is made in the form of three projections uniformly
positioned along the circumference of the cross section of the
inner surface of the clamping sleeve, the center of which is
positioned on the longitudinal axis of symmetry of the tool.
10. The tool according to claim 8, characterized in that the
projection on the clamping sleeve is made in the form of a figured
tongue.
11. The tool according to claim 1, characterized in that the length
of the clamping sleeve along the longitudinal axis of symmetry of
the tool is less than the length of the second part of the stem
along that axis.
12. The tool according to claim 11, characterized in that the
stopping element is an end surface of the clamping sleeve, which
surface faces the third part of the stem.
13. The tool according to claim 1, characterized in that the two
surfaces of the clamping sleeve that are formed when it is split
are positioned parallel to the longitudinal axis of symmetry of the
tool.
14. The tool according to claim 1, characterized in that the two
surfaces of the clamping sleeve that are formed when it is split
are positioned inclined to a plane passing through the longitudinal
axis of symmetry of the tool.
15. The tool according to claim 14, characterized in that it has
equal angles of inclination of the two surfaces that are formed
when the sleeve is split, relative to the plane passing through the
longitudinal axis of symmetry of the tool.
16. The tool according to claim 1, characterized in that the insert
comprises a base secured on the working head, an intermediate part
adjacent the base and formed by a body of revolution with an outer
side surface of concave shape, and a head part adjacent the
intermediate part and formed by a body of revolution with an outer
side surface of convex shape, smoothly matching the outer side
surface of the intermediate part.
17. The tool according to claim 16, characterized in that the
length of the intermediate part of the insert along the
longitudinal axis of symmetry of the tool does not exceed the
length of the head part of the insert along that axis.
18. The tool according to claim 16, characterized in that the
length of the head part of the insert along the longitudinal axis
of the tool does not exceed the length of the intermediate part of
the insert along that axis.
Description
FIELD OF THE INVENTION
[0001] The instant invention relates to the mining industry, in
particular to a cutting tool for breaking mineral and artificial
materials, and may be used in the effectors of mining and boring
machines during the mining of mineral deposits and the formation of
excavations in the earth, and also in actuators of road-building
machines during the building and repair of roads.
BACKGROUND ART
[0002] A cutting tool for breaking mineral and artificial materials
is known that is adapted for being mounted with the possibility for
free rotation in a channel of a support secured on an actuator, the
tool having the form of a body of revolution with a longitudinal
axis of symmetry. The tool comprises a working head, an insert made
of a hard-alloy material and secured to one end of the working
head, and a stem connected to the other end of the working head.
The stem comprises a first part arranged on one end of the stem
from the side of the working head, a second part adjacent the first
part and having a diameter less than the diameter of the first
part, and a third part adjacent the second part, positioned on the
other end of the stem and having a diameter that is not less than
the diameter of the second part. A split clamping sleeve of
cylindrical form is arranged on the second part of the stem and has
a stopping element serving to fix it from movements along the
longitudinal axis of symmetry of the tool relative to the stem. A
protective element has a through axial hole and is mounted on the
clamping sleeve (see, for example, laid-open German application No.
19630642, class E21 C 35/18, published 5 Feb. 1998).
[0003] In the known tool, in order to arrange the stem in the axial
channel of the support, the clamping sleeve is deformed by applying
an impact load to the tool in the axial direction. A drawback of
this technical solution is the large labor expenditure of the work
in respect to mounting the tool in the channel of the support,
which is due to the necessity of providing deformation of the
clamping sleeve in constrained conditions, in particular during the
replacement directly on the actuator of a tool that has become
inoperative. Furthermore, the aforesaid dynamic action on the
clamping sleeve during the mounting of the tool may result in a
change of its geometrical shape, which may result in disturbance of
the conditions for free rotation of the stem in the channel of the
support during operation.
[0004] A cutting tool for breaking mineral and artificial materials
is also known that is adapted for being mounted with the
possibility for free rotation in a channel of a support secured on
an actuator, the tool having the form of a body of revolution with
a longitudinal axis of symmetry. The tool comprises a working head,
an insert made of a hard-alloy material and secured to one end of
the working head, and a stem connected to the other end of the
working head. The stem comprises a first part arranged on one end
of the stem from the side of the working head, a second part
adjacent the first part and having a diameter less than the
diameter of the first part, and a third part adjacent the second
part, positioned on the other end of the stem and having a diameter
that is not less than the diameter of the second part. A split
clamping sleeve of cylindrical form is made of an elastic material,
is arranged on the second part of the stem and has a stopping
element serving to fix it from movement along the longitudinal axis
of symmetry of the tool relative to the stem. A protective element
has a through axial hole with a diameter exceeding the diameter of
the first part of the stem, and is mounted on the clamping sleeve
with the possibility for axial movement along the sleeve for
positioning it on the first part of the stem during the
installation of the cutting tool in the support (see, for example,
laid-open German application No. 19720635, class E21C 35/18,
published 19 Nov. 1998).
[0005] This tool partially removes the drawbacks of the earlier
described tool, since it eliminates the necessity for dynamic
action on the clamping sleeve during the mounting of the tool. In
this tool the clamping sleeve is deformed to a size ensuring its
free passage into the axial channel of the support by putting a
protective element on the sleeve. In such a condition the tool is
inserted into the channel of the support and then the protective
element is moved onto the first part of the stem, thus freeing the
clamping sleeve. The clamping sleeve under the action of the
elastic force expands in the channel of the support and fixes the
fool in the latter.
[0006] A drawback of this technical solution is the necessity for
relatively strong deformation of the clamping sleeve in order to
obtain a diameter less than the diameter of the channel in the
support. After such compression, residual deformations appear in
the clamping sleeve, which after removal of the protective element
may result in that the clamping sleeve will not reliably hold the
stem in the channel of the support to a sufficient degree.
Preliminary compression during the mounting of the tool and
subsequent expansion of the clamping sleeve may result in a
disturbance of its geometrical shape and, consequently, disturbance
of the free rotation of the stem in the channel of the support in
the process of operation.
[0007] The object of the instant invention is to create a cutting
tool for breaking mineral and artificial materials, the
construction of which would ensure reliable fixation of the tool in
the channel of a support while simultaneously providing convenience
in mounting under operation conditions.
SUMMARY OF THE INVENTION
[0008] This object is achieved in that a cutting tool for breaking
mineral and artificial materials, adapted for installation with the
possibility for free rotation in a channel of a support secured on
an actuator, the tool having the form of a body of revolution with
a longitudinal axis of symmetry and comprising a working head, an
insert made of a hard-alloy material and secured to one end of the
working head, a stem connected to the other end of the working head
and comprising a first part arranged on one end of the stem from
the side of the working head, a second part adjacent the first part
and having a diameter less than the diameter of the first part, and
a third part adjacent the second part, positioned on the other end
of the stem and having a diameter that is not less than the
diameter of the second part, a split clamping sleeve made of an
elastic material, arranged on at least the second part of the stem
and having a stopping element serving to fix it against movement
along the longitudinal axis of symmetry of the tool relative to the
stem, a protective element having a through axial hole with a
diameter exceeding the diameter of the first part of the stem and
mounted on the clamping sleeve with the possibility for axial
movement along the sleeve for positioning it on the first part of
the stem during the installation of the cutting tool in the channel
of the support. In accordance with the invention the protective
element is disposed at a distance ranging from 0.6 to 0.85 of the
length of the clamping sleeve with respect to the end of the sleeve
oriented towards the working head along the longitudinal axis of
symmetry of the tool, wherein the diameter of the first part of the
stem is greater than the diameter of the third part thereof.
[0009] The aforesaid construction of the tool provides for a
conical shape of the clamping sleeve inserted into the support,
which ensures a reduction of the laboriousness of mounting under
operating conditions with a simultaneous reduction of the degree of
deformation of the clamping sleeve by the protective element, as a
result of which the reliability of both parts of the tool and
fixation of the stem in the support is enhanced.
[0010] The diameter of the through hole in the protective element
may exceed the diameter of the channel of the support.
[0011] In that case the diameter of the clamping sleeve prior to
insertion of the tool into the channel of the support is greater
than the diameter of the channel of the support. Such a structural
solution is related to the fact that during lengthy storage of the
tools, a clamping sleeve made of an elastic material (for example,
spring steel) and being in a compressed state "tires" and after
removal of the protective element may not assume the necessary
geometrical parameters. In that case the reliability of fixation of
the cutting tool in the channel of the support is impermissibly
reduced. The proposed construction increases the reliability of
fixation of the tool in the support.
[0012] The protective element may be made in the form of a flat
washer. With such a variant of structural embodiment of the
protective element, the abrasive wear of tool units during
operation is reduced, which improves the conditions for free
rotation of the stem in the channel of the support.
[0013] The protective element may be made in the form of a washer
having a U-shaped form in cross section. With such a variant of
structural embodiment of the protective element, additional
protection of the support and parts of the tool against eroded
material is provided.
[0014] The protective element may be made in the form of a disk
spring washer. With such a variant of structural embodiment of the
protective element, a reduction of the dynamic loads on parts of
the tool is ensured and this results in enhancement of the
operation reliability of the tool.
[0015] The washer may be provided with an annular projection
positioned along the through axial hole of the washer, facing the
third part of the stem and adapted for arrangement in a
corresponding input aperture of the channel of the support, which
makes it possible to ensure better centering of the stem relative
to the clamping sleeve and the channel of the support, and,
consequently, improve the conditions for rotation of the stem in
that channel.
[0016] The clamping sleeve may be arranged on the second and third
parts of the stem, and its length along the longitudinal axis of
symmetry of the tool may exceed the sum length of the second and
third parts of the stem along that axis, which ensures an
additional reduction of the laboriousness of mounting the tool in
the channel of the support while simultaneously reducing wear of
the channel of the support.
[0017] The stopping element may be made in the form of at least one
projection positioned on the inner surface of the clamping sleeve,
while the second part of the stem may have an annular recess for
the arrangement of that projection. With such a variant of the
structural embodiment, the reliability of the connection of the
stem to the clamping sleeve increases.
[0018] The stopping element may be made in the form of three
projections, uniformly positioned along the circumference of the
cross section of the inner surface of the clamping sleeve, the
center of which is positioned on the longitudinal axis of symmetry
of the tool, which ensures enhancement of the conditions of free
rotation of the stem in the channel of the support as a result of
centering of the stem relative to the clamping sleeve.
[0019] The projection on the clamping sleeve may be made in the
form of a figured tongue, which makes it possible to reduce the
laboriousness of making the tool.
[0020] The length of the clamping sleeve along the longitudinal
axis of symmetry of the tool may be less than the length of the
second part of the stem along that axis, which ensures an
additional reduction of laboriousness of mounting the tool in the
support.
[0021] The stopping element may be an end surface of the clamping
sleeve, which surface faces the third part of the stem, this making
it possible to simplify the construction of the tool.
[0022] The two surfaces of the clamping sleeve that are formed when
it is split may be positioned parallel to the longitudinal axis of
symmetry of the tool. Such a variant of embodiment makes it
possible to improve the exit of broken material from the annular
channel formed by the inner surface of the clamping sleeve and the
outer surface of the stem, which improves the conditions for free
rotation of the stem in the channel of the support.
[0023] The two surfaces of the clamping sleeve that are formed when
it is split may be positioned inclined to the plane passing through
the longitudinal axis of symmetry of the tool. This also makes it
possible to additionally improve the exit of broken material from
the annular channel formed by the inner surface of the clamping
sleeve and the outer surface of the stem, and consequently improve
the conditions for free rotation of the stem in the channel of the
support.
[0024] The tool my have equal angles of inclination of the two
surfaces, formed when the sleeve is split, relative to the plane
passing through the longitudinal axis of symmetry of the tool. This
makes it possible to somewhat reduce the laboriousness of making
the tool.
[0025] Each surface, formed during the split of the clamping
sleeve, may be made helical. This makes it possible to improve the
exit of broken material from the annular channel formed by the
inner surface of the clamping sleeve and the outer surface of the
stem, which improves the conditions for free rotation of the stem
in the channel of the support.
[0026] The insert may comprise a base secured on the working head,
an intermediate part adjacent the base and formed by a body of
revolution with an outer side surface of concave shape, and a head
part adjacent the intermediate part and formed by a body of
revolution with an outer side surface of convex shape, smoothly
matching the outer side surface of the intermediate part. With such
a variant of structural embodiment of the insert, the conditions
for free rotation of the stem in the channel of the support are
additionally enhanced and simultaneously stability of the level of
the load on the parts of the tool are maintained for the whole
period of operation of the latter, which makes it possible to
increase the operational reliability of the tool.
[0027] The length of the intermediate part of the insert along the
longitudinal axis of symmetry of the tool may not exceed the length
of the head part of the insert along that axis.
[0028] The length of the head part of the insert along the
longitudinal axis of symmetry of the tool may not exceed the length
of the intermediate part of the insert along that axis.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] FIG. 1 shows a first variant of embodiment of a cutting tool
for breaking mineral and artificial materials, in accordance with
the invention.
[0030] FIG. 2--a second variant of embodiment of the tool, in
accordance with the invention.
[0031] FIG. 3--a third variant of embodiment of the tool, in
accordance with the invention.
[0032] FIG. 4--a fourth variant of embodiment of the tool, in
accordance with the invention.
[0033] FIG. 5--a fifth variant of embodiment of the tool, in
accordance with the invention.
[0034] FIG. 6--a clamping sleeve of the tool.
[0035] FIG. 7--a perspective view of another variant of embodiment
of the clamping sleeve.
[0036] FIG. 8--a view along the arrow A in FIG. 6.
[0037] FIG. 9--a protective element of the tool.
[0038] FIG. 10--an insert of the working head of the tool.
[0039] FIG. 11--front view with a section cut of the tool mounted
in the support.
[0040] FIG. 12--front view with a section cut of the tool mounted
in the support in another variant of embodiment.
DETAILED DESCRIPTION OF THE PREFERABLE VARIANTS OF EMBODIMENT OF
THE INVENTION
[0041] The cutting tool for breaking mineral and artificial
materials has the form of a body of revolution with a longitudinal
axis of symmetry and comprises a working head 1 (FIGS. 1-5), which
may have any geometrical shape, preferably the form of a body of
revolution. An insert 3 made of a hard-alloy material is secured on
one end 2 of the working head 1. Preferably, the insert 3 has the
shape of a body of revolution and may be secured on the working
head 1 with the aid of any known undetachable or detachable
connection, preferably, with the aid of soldering.
[0042] A stem 4 has the form of a body of revolution and may be
made as an integer whole with the working head 1 or connected to
another end 5 of the head 1 with the aid of a detachable or
undetachable connection. The stem 4 comprises a first part 6,
positioned at one end of the stem 4 from the side of the working
head 1, a second part 7, adjacent part 6, and a third part 8,
adjacent part 7 and positioned on the other end of the stem 4. The
diameter of part 6 is greater than the diameter of part 7 or part
8.
[0043] A cut clamping sleeve 9 of cylindrical form, made from an
elastic material, for example, steel, is arranged on at least part
7 (FIG. 3).
[0044] The sleeve 9 has a stopping element 10 serving to fix it
from movement along the longitudinal axis of symmetry of the tool
relative to the stem 4.
[0045] A protective element 11 with a through axial hole 12 (FIG.
9) is mounted on the clamping sleeve 9 with the possibility for
axial movement. The protective element 11 serves to reduce the wear
of the facing each other surfaces of respectively the stem 4 and
support 13 of the cutting tool (FIGS. 11, 12), and also to prevent
the ingress of the broken material (slack) into annular channel 14
formed by the inner surface of the clamping sleeve 9 and the side
surface of the stem 4. The diameter D of the through axial hole 12
in the protective element 11 exceeds the diameter d of the first
part 6 of the stem 4, that is the condition: D>d, is fulfilled.
The protective element 11 is positioned at a distance K, which is
not less than 0.6 and not more than 0.85 the length M of the
clamping sleeve 9 along longitudinal axis 15 of symmetry of the
tool relative to end 16 of the clamping sleeve 9, which faces the
working head 1, that is the condition: 0.6 M<K<0.85 M, is
fulfilled. Wherein, base point 17, to which the value of the
distance K is determined, is taken to be the point of the beginning
of contact of the protective element 11 with the clamping sleeve 9
from the side of the working head 1. The values of the range of
geometrical ratios between the parts of the tool, which are
indicated above, have been obtained in an empirical manner. In the
case where the geometrical ratios extend beyond the upper limit of
the indicated range, an arbitrary sliding of the protective element
11 from the clamping sleeve 9 may occur during transportation of
the tool or when it is being mounted in the support 13. In the case
where the geometrical ratios extend beyond the lower limit of the
indicated range, the clamping sleeve 9 will not acquire a conical
shape which is the optimum shape for mounting the tool in the
support 13. The diameter d of the first part 6 of the stem 4
exceeds the diameter C of its third part 8, i.e., the condition:
C<d, is fulfilled. Fulfillment of this condition makes it
possible to give the clamping sleeve 9 the shape of a truncated
cone during the mounting of the tool in the support 13. In the case
where the condition indicated above between the diameters of the
first part 6 and the third part 8 of the stem 4 is not fulfilled,
its part 8 will prevent the formation of a conical shape of the
clamping sleeve 9 during the mounting of the tool in the support
13.
[0046] The protective element 11 may have any geometrical shape,
mainly the form of a body of revolution, and additionally provides
deformation of the clamping sleeve 9, thus ensuring that the latter
takes on the predetermined geometrical shape during the mounting of
the tool in the support 13. The most advisable variant is that
variant of the structural embodiment of the protective element 11
wherein it is made in the form of a flat washer (FIG. 2), i.e., the
face surfaces of the washer are planes. In the case of such a
variant of structural embodiment of the protective element 11 it is
preferable that it be made with an annular projection 18 (FIGS. 3,
11) positioned along the through axial hole 12 of the protective
element 11, facing the third part 8 of the stem 4 and adapted for
arrangement in a corresponding input hole 19 of channel 20 of the
support 13 (FIGS. 11, 12). The projection 18 and corresponding hole
19 may have any geometrical shape.
[0047] The protective element 11 may be made in the form of a
washer having a U-shaped form in cross section (FIG. 12). In that
case it is most advisable that this washer be made with an annular
axial projection 18 positioned along the hole of the washer and
facing the third part 8 of the stem 4 for arrangement in a
corresponding input hole 19 of channel 20 of the support 13.
[0048] The protective element 11 may be made in the form of a disk
spring washer (FIG. 9). In that case it is most advisable that this
washer also be made with the annular projection 18 described above
for arrangement in input hole 19 of channel 20 of the support
13.
[0049] It is preferable that the diameter of the through hole 12 of
the protective element 11 exceed the diameter of the channel 20 of
the support 13, as is shown in FIGS. 11, 12. Such a construction
increases the reliability of securing the tool in the support.
[0050] In accordance with one of the variants of structural
embodiment of the device, the clamping sleeve 9 is arranged on the
second part 7 and third part 8 of the stem 4 and its length M along
the longitudinal axis 15 of symmetry of the tool exceeds the sum of
the length L of the second part 7 of the stem 4 and the length S of
the third part 8 of the stem 4 along the same axis 15, that is the
condition: M>L+S, is fulfilled. This ratio of the geometrical
parameters of the parts of the tool determines that the end of the
clamping sleeve 9 extends beyond the end face of the stem 4 (FIGS.
1, 2, 11). With such a variant of structural embodiment of the
clamping sleeve 9 its stopping element 10 may be made in the form
of at least one projection positioned on the inner surface of the
clamping sleeve 9, and the stem 4 has a recess 21 for the
accommodation of that projection (FIGS. 1, 2, 4, 11). The
projection forming the stopping element 10 on the clamping sleeve 9
may be made in the form of a separate part, secured on the clamping
sleeve 9 with the aid of a detachable or undetachable connection,
or be made by pressing a section of the clamping sleeve 9 inwards,
i.e., may be made as one whole with the clamping sleeve 9. Most
advisable is execution of the stopping element 10 in the form of
three projections (FIGS. 6, 8), which are positioned uniformly
along the circumference of the cross section of the inner surface
of the clamping sleeve 9, the center of which lies on the
longitudinal axis 15 of symmetry of the tool. The projection on the
clamping sleeve 9 that forms the stopping element 10 may be made in
the form of a figured tongue (FIG. 6). The figured tongue may be
obtained by making a U-shaped through slot on the side surface of
the clamping sleeve 9. Then the section of the clamping sleeve,
which is limited by the aforesaid U-shaped through slot, is bent
back into the inner cavity of the clamping sleeve 9.
[0051] In accordance with another variant of structural embodiment
of the device, the length M of the clamping sleeve 9 along the
longitudinal axis 15 of symmetry of the tool may be less than the
length L of the second part 7 of the stem 4 (FIGS. 3, 12), i.e.,
the condition: M<L , is fulfilled. The indicated ratio of the
geometrical parameters of the parts of the tool determine that the
clamping sleeve 9 may be positioned within the limits of the second
part 7 of the stem 4. With such a variant of structural embodiment
of the clamping sleeve 9, the end face surface 22 may be its
stopping element 10 (FIGS. 7, 12).
[0052] The split clamping sleeve 9 has surfaces 23, 24, formed when
it is split. During a split of the sleeve 9 an additional channel
25 is formed for the passage of the broken material (slack). The
configuration of the additional channel 25 for passage of the
broken products may be of any form. It is preferable that the
surfaces 23, 24, formed during the split of the clamping sleeve 9,
be positioned parallel to the longitudinal axis 15 of symmetry of
the tool. Thus, in FIGS. 1,3, a clamping sleeve 9 is shown, the
surfaces 23, 24 of which are positioned parallel to the
longitudinal axis 15 of symmetry of the device. One of the variants
of structural embodiment of the clamping sleeve 9 provides for the
surfaces 23, 24, formed during the split of the clamping sleeve 9,
being positioned inclined to the plane passing through the
longitudinal axis 15 of symmetry of the tool (FIGS. 2, 6). Wherein,
the angles of inclination of the surfaces 23, 24 relative to the
aforesaid plane may be equal. In accordance with another variant of
structural embodiment of the clamping sleeve, each surface 23, 24,
formed during the split of the clamping sleeve 9, may have the
shape of a helical surface.
[0053] The insert 3 of hard-alloy material may comprise a head part
26, a base 27 secured to the working head 1, and an intermediate
part 28 positioned between the head part 26 and base 27 (FIG. 10).
The intermediate part 28 of the insert 2 is formed by a body of
revolution with an outer side surface of concave shape. Wherein,
the head part 26 of the insert is formed by a body of revolution
with an outer side surface of convex shape. The side surface of the
head part 26 of the insert 3 smoothly conjugates with the side
surface of its intermediate part 28. In accordance with one of the
variants of structural embodiment of the tool, the length E of the
intermediate part 28 of the insert 3 along the longitudinal axis 15
of symmetry of the tool should not exceed the length F of the head
part 26 of the insert 3 along that same axis 15, i.e., the
condition: E<F , is fulfilled. In accordance with another
variant, the length F of the head part 26 of the insert 3 along the
longitudinal axis 15 of symmetry of the tool should not exceed the
length E of the intermediate part 28 of the insert 3 along that
same axis 15, i.e., the condition: F<E , should be
fulfilled.
[0054] The cutting tool for breaking mineral and artificial
materials operates in the following manner.
[0055] At first the tool is mounted in the channel 20 of the
support 13, which is secured on an actuator (not shown in the
drawings). In order to do this, the clamping sleeve 9 is mounted on
the stem 4. Then the clamping sleeve 9 is pressed to a diameter
less than the diameter D of the protective element 11. The
protective element 11 is put on the clamping sleeve 9, arranging it
at a certain distance K from the end 16 of the clamping sleeve 9
that faces the working head 1. After the protective element
occupies the indicated position, the clamping sleeve 9 is freed,
and it expands under the action of elastic force. The protective
element 11 prevents further expansion of the clamping sleeve 9, and
it, as a result of application of off-center force created by the
protective element 11, takes on the form of a truncated cone, the
peak of which is oriented towards the third part 8 of the stem 4.
Wherein, the protective element 11 holds the clamping sleeve 9 in a
compressed state, ensuring a predetermined form of the clamping
sleeve 9 during the mounting of the tool. Further, the tool is
inserted into the channel 20 of the support 13 until there is
interaction between the protective element 11 and the end of the
support 13. Wherein, it should be noted that giving the clamping
sleeve 9 the shape of a truncated cone ensures its free entrance
into the channel 20 of the support 13. Then an axial force is
applied to the working head 1, under the action of which the
protective element 11, abutting against the end of the support 13,
moves in an axial direction along the clamping sleeve 9 in the
direction toward the working head 1, while the stem 4 together with
the clamping sleeve 9 enters the channel 20 of the support 13. The
aforesaid introduction of the stem 4 into the channel 20 will
continue until the protective element 11 completely moves to the
first part 6 of the stem 4. When the protective element 11 moves to
part 6 of the stem 4, it frees the clamping sleeve 9, which under
the action of elastic force expands and is pressed against the
walls of the channel 20 of the support 13. Thus, the clamping
sleeve 9 is fixed relative to the support 13. Movement of the stem
4 along the longitudinal axis 15 of symmetry of the tool relative
to the clamping sleeve 9 according to one of the variants of
structural embodiment of the tool (FIGS. 1, 2, 11) is hindered by
the stopping element 10, made in the form of at least one
projection, which after the tool is mounted turns out to be placed
in the recess 21 of the stem 4. According to another variant of the
structural embodiment of the tool (FIGS. 3, 12), the indicated
movement of the stem 4 relative to the clamping sleeve 9 is
prevented by the stopping element 10, i.e., the end surface 22 of
the clamping sleeve 9, which after the tool is mounted interacts
with the third part 8 of the stem 4.
[0056] During movement of the actuator on which the support 13 is
secured with the aid of a detachable or undetachable connection,
the working head 1 with the insert 3 of hard-alloy material enters
into interaction with the broken material. As a result of action of
external forces appearing in the process of interaction of the
working head 1 and the insert 3 with the material being broken, the
stem 4 freely turns about the longitudinal axis 15 of symmetry of
the tool in the channel 20 of the support 13, thus ensuring uniform
wear of the parts of the tool interacting with the material being
broken. The protective element 11 protects the support 13 from
interaction with the material being broken, promotes free rotation
of the tool in the channel 20 of the support 13 and reduces the
wear of the working head 1 and the support 13. After wear of the
insert 3 or the working head 1 or after they have broken, the
defective tool is replaced by a new tool, the mounting of which is
carried out in the manner described above. It should be noted that
during lengthy storage of the tool in a warehouse, residual
deformation of the clamping sleeve 9 may appear, i.e., the clamping
sleeve 9, taking the shape of a truncated cone under the effect of
the protective element 11, partially maintains that shape and after
the tool is positioned in the channel 20 of the support 13. Even in
that case, the reliability of securing the tool in the support is
maintained, since the most loaded end of the clamping sleeve 9,
facing the working head 1, remains virtually undeformed during
storage.
* * * * *