U.S. patent application number 09/727026 was filed with the patent office on 2001-04-12 for cutting tools for drilling concrete, aggregate, masonry or the like materials.
This patent application is currently assigned to Black and Decker Inc.. Invention is credited to Anjanappa, Muniswamappa, Bludis, Thomas Trevor, Crosby, Stephen R., Koehler, Udo, Timmons, Russell M., Williams, John D..
Application Number | 20010000223 09/727026 |
Document ID | / |
Family ID | 26998363 |
Filed Date | 2001-04-12 |
United States Patent
Application |
20010000223 |
Kind Code |
A1 |
Anjanappa, Muniswamappa ; et
al. |
April 12, 2001 |
Cutting tools for drilling concrete, aggregate, masonry or the like
materials
Abstract
A cutting tool (500) has a longitudinally extending shaft
portion (588) with a chucking part (509) and a cutting head (506).
A pressed powder cutting insert (518) with a cutting edge (520) is
on the cutting head (506). The cutting edge (520) includes at least
one cutting portion. A rake surface (524) is formed adjacent to at
least one of the cutting portions (520) with the rake face (524)
being at a rake angle from about 0.degree. to 10.degree.. A
clearance face (526) is formed adjacent to the at least one cutting
portion opposite the rake face (524). The clearance face (526) is
at a clearance angle from about 10.degree. to 50.degree.. An edge
radius (540) between the rake face (524) and the clearance face
(526) is at a radius of from about 0.0015 to about 0.004 inch. The
edge radius 540 is formed during pressing of the powder to form the
insert, thus, enabling the insert to be directly braised into the
cutting head (506).
Inventors: |
Anjanappa, Muniswamappa;
(Ellicott City, MD) ; Crosby, Stephen R.; (White
Hall, MD) ; Timmons, Russell M.; (Lutherville,
MD) ; Williams, John D.; (Champaign, IL) ;
Bludis, Thomas Trevor; (Baltimore, MD) ; Koehler,
Udo; (York, PA) |
Correspondence
Address: |
Harness, Dickey & Pierce, P.L.C.
P.O. Box 828
Bloomfield Hills
MI
48303
US
|
Assignee: |
Black and Decker Inc.
|
Family ID: |
26998363 |
Appl. No.: |
09/727026 |
Filed: |
November 30, 2000 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09727026 |
Nov 30, 2000 |
|
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|
08845524 |
Apr 25, 1997 |
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|
08845524 |
Apr 25, 1997 |
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|
08513586 |
Aug 10, 1995 |
|
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08513586 |
Aug 10, 1995 |
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08354349 |
Dec 12, 1994 |
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Current U.S.
Class: |
408/230 ;
408/144 |
Current CPC
Class: |
B23B 2251/50 20130101;
B23B 2251/04 20130101; Y10T 408/78 20150115; B23B 2251/48 20130101;
Y10T 408/9097 20150115; B23B 31/005 20130101; E21B 10/445 20130101;
B21K 5/02 20130101; B23B 51/02 20130101; B23B 2251/18 20130101;
B23B 2240/08 20130101; E21B 10/46 20130101; B23B 2231/0264
20130101; B23B 2226/75 20130101; B23B 2251/14 20130101 |
Class at
Publication: |
408/230 ;
408/144 |
International
Class: |
B23B 051/02 |
Claims
Claims:
1. A cutting tool for boring concrete or the like material
comprising: a longitudinally extending shank portion defining a
longitudinal axis having two ends; a chucking part provided at one
end of the shank portion; a cutting head provided at the other end
of said shank portion, a pressed powder cutting insert in said
cutting head, a cutting edge on said cutting insert, said cutting
edge having at least one cutting edge portion, a rake face, formed
during said pressing of said powder, adjacent said cutting edge,
said rake face being at a rake angle from about 0.degree. to about
10.degree..
2. The cutting tool according to claim 1, wherein at least two
cutting edge portions each include a rake surface.
3. The cutting tool according to claim 1, wherein said rake face
angle is preferably about 5.degree..
4. The cutting tool according to claim 1, wherein said rake face
angle is positive.
5. A cutting tool for boring concrete or the like material
comprising: a longitudinally extending shank portion defining a
longitudinal axis and having two ends; a chucking part provided at
one end of the shank portion; a cutting head provided at the other
end of said shank portion, a pressed powder cutting insert on said
cutting head, a cutting edge on said cutting insert, said cutting
edge including at least one cutting edge portion, a rake face
formed adjacent said at least one cutting portion, a clearance face
formed adjacent said at least one cutting portion opposing said
rake face, said rake face and clearance face formed during pressing
of the powder, and an edge radius between said rake face and
clearance face, said edge radius having a radius of about 0.0015 to
0.004 inch.
6. The cutting tool according to claim 11, including at least two
cutting edge portions, both cutting edge portions include a rake
surface.
7. The cutting tool according to claim 5, wherein said clearance
face is at an angle of about 30.degree. to about 40.degree..
8. The cutting tool according to claim 5, wherein said edge radius
is preferably from about 0.002 to about 0.003.
9. The cutting tool according to claim 5, wherein an egress face is
adjacent said rake face.
10. The cutting tool according to claim 9, wherein said egress face
is at an angle of about 80.degree. to about 100.degree..
11. The cutting tool according to claim 10, wherein said egress
face is at an angle of about 90.degree..
12. A cutting tool for concrete, aggregate or the like material
comprising: a longitudinally extending shank portion defining a
longitudinal axis and having two ends; a chucking part provided at
one end of the shank portion; a cutting head provided at the other
end of said shank portion, a pressed powder cutting insert in said
cutting head, a cutting edge formed on said cutting insert, said
cutting edge having at least one cutting edge portion, a rake
surface formed adjacent said cutting edge during pressing of the
powder, said rake surface being at a positive rake angle.
13. A method of boring a hole in concrete, aggregate or the like
material comprising: providing a cutting tool including a
longitudinally extending shank portion defining a longitudinal axis
and having two ends, a chucking part provided at one end of the
shank portion, a cutting head provided at the other end of said
shank portion, a pressed powder cutting insert in said cutting
head, a cutting edge on said cutting insert, said cutting edge
having at least one cutting edge portion, a rake surface formed
adjacent said cutting edge portion, said rake face being at a rake
angle from about 0.degree. to about 10.degree.; contacting said
cutting edge with the material; rotating said cutting tool to cut
said material; and forming a hole in said material.
14. The method of claim 13, including applying a force along said
longitudinal axis of said cutting tool.
15. The method of claim 14, wherein said force is constant.
16. The method of claim 14, wherein said force is sequentially
repetitious to impact the material to chisel the material.
17. A method of boring a hole in concrete, aggregate or the like
material comprising: providing a cutting tool including a
longitudinally extending shank portion defining a longitudinal axis
and having two ends, a chucking part provided at one end of the
shank portion, a cutting head provided at the other end of said
shank portion, a pressed powder cutting insert in said cutting
head, a cutting edge on said cutting insert, said cutting edge
having at least one cutting edge portion, a rake surface formed
adjacent said cutting edge portion, said rake face being at a rake
angle from about 0.degree. to about 10.degree.; contacting said
cutting edge with the material; impacting said cutting tool to
chisel said material; and forming a hole in said material.
18. The method of claim 17, including rotating said cutting tool to
cut the material.
19. A method of boring a hole in concrete, aggregate or the like
material comprising: providing a cutting tool including a
longitudinally extending shank portion defining a longitudinal axis
and having two ends, a chucking part provided at one end of the
shank portion, a cutting head provided at the other end of said
shank portion, a pressed powder cutting insert in said cutting
head, a cutting edge on said cutting insert, said cutting edge
including at least one cutting edge portion, a rake surface formed
adjacent said at least one cutting portion, a clearance face formed
adjacent said at least one cutting portion opposing said rake face,
and an edge radius between said rake face and clearance face, said
edge radius of from about 0.0015 to 0.004 inch; contacting said
cutting edge with the material; rotating said cutting tool to cut
said material; and forming a hole in said material.
20. The method of claim 19, including applying a force along said
longitudinal axis of said cutting tool.
21. The method of claim 20, wherein said force is constant.
22. The method of claim 21, wherein said force is sequentially
repetitious to impact the material to chisel the material.
23. A method of boring a hole in concrete, aggregate or the like
material comprising: providing a cutting tool including a
longitudinally extending shank portion defining a longitudinal axis
and having two ends, a chucking part provided at one end of the
shank portion, a cutting head provided at the other end of said
shank portion, a pressed powder cutting insert in said cutting
head, a cutting edge on said cutting insert, said cutting edge
including at least one cutting edge portion, a rake surface formed
adjacent said at least one cutting portion, a clearance face formed
adjacent said at least one cutting portion opposing said rake face,
and an edge radius between said rake face and clearance face, said
edge radius having a radius of from about 0.0015 to 0.004 inch;
contacting said cutting edge with the material; impacting said
cutting tool to chisel said material; and forming a hole in said
material.
24. The method of claim 23, including rotating said cutting tool to
cut the material.
25. A method of forming an insert comprising: providing a mold with
an insert cavity defining a longitudinal axis and having an opening
along the longitudinal axis; adding powder material into the mold;
compressing the material in the direction of the longitudinal axis;
forming the insert with a positive rake face.
26. The method of forming an insert according to claim 25 further
comprising a V-shaped punch compressing said powder material.
27. The method of forming an insert according to claim 25 and
forming a land on a face of said insert, said land being at an
acute angle and counter clockwise with respect to an axis of the
insert.
28. The method of forming an insert according to claim 25, wherein
said insert has a desired rake face, clearance face and edge
radius.
29. The method of forming an insert according to claim 25 and
ejecting the insert from the mold.
Description
1. This application is a continuation-in-part of U.S. patent
application Ser. No. 08/354,349, filed Dec. 12, 1994, entitled
CUTTING TOOLS FOR DRILLING CONCRETE, AGGREGATE, MASONRY OR THE LIKE
MATERIALS, the specification and drawings of which are expressly
incorporated by reference.
BACKGROUND OF THE INVENTION
2. The present invention relates to cutting tools or drill bits,
and more particularly, to cutting tools which are used in
hammering, percussive, or rotary boring or drilling applications in
concrete, aggregate, masonry or the like material.
3. When drilling concrete, aggregate or the like materials,
generally three different types of cutting tools or bits are used.
These bits can be defined as hammer bits, percussive bits, and
rotary masonry bits. In a true hammer bit, the bit is placed into a
driver which includes a hammer which is sequentially and
repetitiously moved toward and away from the bit. This hammering
action hammers the bit. While the bit is being hammered, the bit
continues to either passively or actively rotate. Thus, this type
of cutting would be synonymous with using a chisel and hitting it
with a hammer. Also, the driver may include a rotational feature
where the bit is hammered and actively rotated.
4. In percussive drilling, the drive includes a chuck which is
associated with stepping cam surfaces on gears which are rotated
and, at the same time, moved up and down within the driver. Thus,
the entire chuck mechanism rotates and moves up and down during the
cutting process.
5. A rotary masonry bit is positioned into a driver which provides
only a rotary movement. Thus, the rotary masonry bit does not move
up and down and just rotates to cut at the concrete or
aggregate.
6. Cutting tools in these three fields require different parameters
for each type of application. In hammer and percussive bits, which
utilize a chiseling action, the tip cutting angle, which provides
tip strength, debris elimination and a cutting or rake face are a
primary concern. Likewise, in rotary masonry drilling, which uses
purely rotary movement, the cutting or rake face, debris clean out
and cutting angle are also of primary importance. However, all of
these elements are interrelated to provide an optimum cutting tool
or drill bit to drill concrete, aggregate and the like
materials.
7. Existing hammer and percussive cutting tools ordinarily include
carbide insert tips with cutting edges which have large obtuse
included angles as well as a negative rake face at large acute
angles. Thus, the tip has been utilized to chisel and rotate to
drill or bore into the concrete material. The rotary masonry bits
ordinarily use a rake face on the bit so that when it is rotated,
it will bore through the concrete material.
8. Further, when the carbide tips are formed, the carbide powder is
laterally pressed into a mold to form the tip. This tip is inserted
directly and welded or brazed onto a tool shank. Thus, this is the
art accepted way to form current design tools or bits.
SUMMARY OF THE INVENTION
9. Accordingly, it is an object of the present invention to provide
the art with a cutting tool or bit which will reduce the time to
drill holes into concrete, aggregate or the like material and
improve the quality of the hole. The present invention has an
improved cutting tip with a rake face which is slightly negative,
zero or positive. The tip cutting angle, which is the angle between
the rake face and clearance face, is smaller than current designs
to provide better chiseling action. Also, the insert can be formed
from pressed powder and maintain the desired tip cutting angle. The
debris recess of the present invention rapidly ejects debris from
the tip into the helical flutes. A rake face on the cutting tools
increases cutting action during rotation of the cutting tools in
the hole.
10. Also, in accordance with one aspect of the present invention,
the formed carbide tip is worked, contrary to conventional
teaching, to increase performance of the tip in drilling concrete,
aggregate, masonry or the like material. The term "works" means the
tip is ground or otherwise to sharpen or form a sharpened cutting
edge on the tool. In another aspect, it has been found that the
insert can be pressed powdered metal and still maintain the desired
tip cutting angle. Further, in a ball head design tool, the present
invention has a larger egress space. Egress space is defined as the
open volume through which debris may pass on its way from being
created to the flute of the bit to enable faster removal of
debris.
11. In accordance with a second aspect of the invention, a cutting
tool comprises a longitudinally extending shank portion which
defines a longitudinal axis and two ends. One end has a chucking
part and the other end has a cutting head. A cutting edge is on the
cutting head and includes at least one cutting portion. A rake
surface is formed adjacent to at least one of the cutting portions.
Also, a clearance face is formed adjacent to the at least one
cutting portion opposite the rake face. An edge radius is formed
between the rake face and the clearance face and has a radius from
about 0.0005 to 0.001 inch. Likewise, a method of boring a hole in
concrete, aggregate or the like material is disclosed using the
above cutting tool. The cutting edge of the cutting tool is placed
in contact with the concrete, aggregate or the like material. The
cutting tool is rotated to bore the material. Due to the boring, a
hole is formed in the material. Alternately, instead of rotating
the tool, the tool may be impacted to chisel away the material to
form the hole. Optionally both boring and impacting may be
conducted simultaneously.
12. In accordance with a third aspect of the invention, a cutting
tool includes a longitudinally extending shank with a chucking end
and a cutting head. A cutting edge is formed in the cutting head
with at least one cutting edge portion. A rake surface is formed
adjacent to at least one of the cutting portions with the rake face
at an angle of from about -10.degree. to 10.degree.. A method for
boring a hole in concrete, aggregate or the like material is
disclosed using the above cutting tool. The cutting edge of the
cutting tool is placed in contact with the material. The cutting
tool is rotated to bore the material. Due to the boring, a hole is
formed in the material. Alternatively, instead of rotating the
tool, the tool may be impacted to chisel away the material to form
the hole. Optionally both boring and impacting may be conducted
simultaneously.
13. In accordance with a fourth aspect of the invention, a cutting
tool includes a shank portion with a chucking end and a cutting
head. The head includes a cutting edge with at least one cutting
edge portion. A rake surface is formed adjacent to at least one
cutting edge portion. Additionally, a clearance surface, is formed
adjacent to the at least one cutting portion opposite the rake
face. One or both the rake surface and clearance surface are worked
to form a sharpened edge radius. A method of boring a hole in
concrete, aggregate or the like material is disclosed using the
cutting tool. The cutting edge of the cutting tool is placed in
contact with the material. The cutting tool is rotated to bore the
material. Due to the boring, a hole is formed in the material.
Alternatively, instead of rotating the tool, the tool may be
impacted to chisel away the material to form the hole. Optionally
both boring and impacting may be conducted simultaneously.
14. In accordance with a fifth aspect of the invention, a cutting
tool comprises a longitudinal shank with a chucking part at one end
and a cutting head at the other end. The cutting head includes a
cutting edge with at least one cutting edge portion. A rake surface
is formed adjacent to the at least one of the cutting edge portion.
A primary egress surface is formed immediately adjacent the rake
surface such that the rake surface, and primary egress surface
define a new egress path. A method for boring a hole in concrete
aggregate or the like material is disclosed using the above cutting
tool. The cutting edge of the cutting tool is placed in contact
with the material. The cutting tool is rotated to bore the
material. Due to the boring, a hole is formed in the material.
Alternatively, instead of rotating the tool, the tool may be
impacted to chisel away the material to form the hole. Optionally
both boring and impacting may be conducted simultaneously.
15. In accordance with a sixth aspect of the invention, a cutting
tool comprises a longitudinally extending shank with a chucking
part at one end and a cutting head at the other end. The cutting
head includes a cutting edge with at least one cutting edge
portion. A rake surface is formed adjacent to the at least one
cutting edge portion. The rake surface includes a worked portion
which extends from the cutting edge portion to define a length of
relief. The depth of the length of relief is a ratio to tool
diameter of about 0.10 to 0.32 inches per inch diameter of the
tool. A method for boring a hole into concrete, aggregate or the
like material is disclosed using the above cutting tool. The
cutting edge of the cutting tool is placed in contact with the
aggregate. The cutting tool is rotated to bore the material. Due to
the boring, a hole is formed in the material. Alternatively,
instead of rotating the tool, the tool may be impacted to chisel
away the material to form the hole. Optionally both boring and
impacting may be conducted simultaneously.
16. In accordance with a seventh aspect of the invention, a cutting
tool comprises a longitudinally extending shank portion which
defines a longitudinal axis and two ends. One end has a chucking
part and the other end has a cutting head. A press powdered metal
cutting insert is secured on the cutting head. A cutting edge is on
the cutting insert and includes at least one cutting portion. A
rake surface is formed, during pressing of the powder, adjacent to
at least one of the cutting portions. Also, a clearance face is
formed adjacent to the at least one cutting portion opposite the
rake face. An edge radius is formed between the rake face and the
clearance face and has a radius of from about 0.0015 to 0.004 inch.
Likewise, a method of boring a hole in concrete aggregate or the
like material is disclosed using the above cutting tool. The
cutting edge of the cutting tool is placed in contact with the
concrete aggregate or the like material. The cutting tool is
rotated to bore the material. Due to the boring, a hole is formed
in the material. Alternatively, instead of rotating the tool, the
tool may be impacted to chisel away the material to form the hole.
Optionally, both boring and impacting may be conducted
simultaneously.
17. In accordance with an eighth aspect of the invention, a cutting
tool includes a longitudinally extending shank with a chucking end
and a cutting head. A cutting insert is secured in the cutting
head. A cutting edge is formed in the cutting insert with at least
one cutting edge portion. A rake surface is formed, during the
powder pressing process, adjacent to at least one of the cutting
edge portions with the rake face at an angle from 0.degree. to
about 10.degree.. A method for boring a hole in concrete, aggregate
or the like materials disclosed using the above cutting tool. The
cutting edge of the cutting tool is placed in contact with the
material. The cutting tool is rotated to bore the material. Due to
the boring, a hole is formed in the material. Alternatively,
instead of rotating the tool, the tool may be impacted to chisel
away the material to form the hole. Optionally, both boring and
impacting may be conducted simultaneously.
18. In accordance with a ninth aspect of the invention, an insert
is formed by a press powdered metal operation. A mold is provided
with an insert cavity which defines a longitudinal axis and has an
opening along the longitudinal axis. Powdered metal material is
added into the mold. The powdered metal material is compressed in
the direction of the longitudinal axis to form the insert. The
method forms inserts like that described in the seventh and eight
aspects. The method includes a V-shaped punch to compress the
powdered metal material. Also during compressing of the insert, a
land is formed on the face of the insert. The land is at an acute
angle and counter clockwise with respect to the axis of the insert.
The land and the rake face may be joined in a radius.
19. Additional objects and advantages of the invention will be
apparent from the detailed description of the preferred embodiment,
the appended claims and the accompanying drawings, or may be
learned by practice of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
20. The accompanying drawings, which are incorporated in and
constitute a part of the specification, illustrate two embodiments
of the present invention and together, with the description, serve
to explain the principles of the invention. In the drawings, the
same reference numeral indicates the same parts.
21. FIG. 1 is a perspective view of a prior art cutting tool.
22. FIG. 2 is a side plan view of the cutting tool of FIG. 1.
23. FIG. 3 is a side plan view, rotated 90.degree., of the cutting
tool of FIG. 1.
24. FIG. 4 is a top plan view of the cutting tool of FIG. 1.
25. FIG. 5 is an auxiliary view along the cutting edge of the
cutting tool of FIG. 2 illustrating the rake surface.
26. FIG. 6 is a perspective view of another prior art cutting
tool.
27. FIG. 7 is a side plan view of the cutting tool of FIG. 6.
28. FIG. 8 is a side plan view, rotated 90.degree., of the cutting
tool of FIG. 6.
29. FIG. 9 is a top plan view of the cutting tool of FIG. 6.
30. FIG. 10 is an auxiliary view along the cutting edge of the
cutting tool of FIG. 7 illustrating the rake surface.
31. FIG. 11 is an enlarged side plan view of a cutting radius of
FIGS. 5 and 10 in circle 11.
32. FIG. 12 is a perspective view of a cutting tool in accordance
with the present invention.
33. FIG. 13 is a side plan view of the cutting tool of FIG. 12.
34. FIG. 14 is a side plan view, rotated 90.degree., of the cutting
tool of FIG. 12.
35. FIG. 15 is a top plan view of the cutting tool of FIG. 12.
36. FIG. 16 is an auxiliary view along the cutting edge of the
cutting tool of FIG. 12 illustrating the rake surface.
37. FIG. 17 is a perspective view of an alternate embodiment of the
present invention.
38. FIG. 18 is a side plan view of the cutting tool of FIG. 17.
39. FIG. 19 is a side plan view, rotated 90.degree., of the cutting
tool of FIG. 17.
40. FIG. 20 is a top plan view of the cutting tool of FIG. 17.
41. FIG. 21 is an auxiliary view along the cutting edge of the
cutting tool of FIG. 17 illustrating the rake surface.
42. FIG. 22 is an enlarged view of the edge radius of FIGS. 16 and
21 within circle 22.
43. FIG. 23 is a side plan view, partially in section, of the
cutting tool of FIG. 12 rotating within a material.
44. FIG. 24 is a view like FIG. 23 with the cutting tool impacting
or chiseling the material.
45. FIG. 25 is a partial cross section of a side plan view of the
cutting tool of FIG. 17 in the material during rotary boring.
46. FIG. 26 is a figure like that of FIG. 25 with the cutting tool
impacting or chiseling the material.
47. FIG. 27 is a figure like that of FIG. 25 with the cutting tool
rotating and impacting or chiseling the material.
48. FIG. 28 is an auxiliary view along the cutting edge of a
cutting tool of an alternate embodiment illustrating an arcuate
first egress surface and area.
49. FIG. 29 is a side plan view of another embodiment of a cutting
tool with a 180.degree. included angle.
50. FIG. 30 is a side plan view like FIG. 29 rotated
90.degree..
51. FIG. 31 is a perspective view of an alternate embodiment of the
present invention.
52. FIG. 32 is a side plan view of the cutting tool of FIG. 31.
53. FIG. 33 is a side plan view, rotated 90.degree., of the cutting
tool of FIG. 31.
54. FIG. 34 is an auxiliary view along the cutting edge of the
cutting tool of FIG. 31 illustrating the rake surface.
55. FIG. 35 is a top plan view of the cutting tool of FIG. 31.
56. FIG. 36 is an enlarged view of the edge radius of FIG. 34.
57. FIG. 37 is an enlarged auxiliary view like that of FIG. 34.
58. FIG. 38 is a plan view of an insert in accordance with the
present invention.
59. FIG. 39 is a schematic elevation view of a mold in accordance
with the invention.
60. FIG. 40 is a section view along line 40-40 of FIG. 39.
61. FIG. 41 is a section view along line 41-41 of FIG. 39.
DESCRIPTION OF PRIOR ART DRAWINGS
62. Turning to FIGS. 1 through 11, two prior art cutting tools are
illustrated. FIGS. 1 through 5 illustrate a ball head single flute
cutting tool, while FIGS. 6 through 10 illustrate a double helix
cutting tool. FIG. 11 illustrates the edge radius of both the
cutting tools.
63. The ball head single helix cutting tool is designated with the
reference numeral 100 and the double helix reference tool is
designated with the reference numeral 102. The single flute cutting
tool 100 has a chucking end 104 for a hammer driver and a ball
cutting head 106. The shank 108 has the single helix 110 defining a
flute 112. The flute 112 ends at the cutting head 106 at a debris
channel 114. Also, an additional debris channel 116 is on the
opposing side of the head, which dumps directly into the flute 112,
as seen in FIG. 3.
64. The cutting head 106 includes an insert 118, which includes a
cutting edge 120, either brazed or welded or the like into a slot
122 in the cutting head 106. The insert is formed by placing
powdered carbide into a mold and compressing it. The insert is
directly welded or brazed as described.
65. The cutting edge 120 is defined by rake faces 124, edge radius
125, and clearance faces 126. Ordinarily, first egress faces 128
are directly adjacent to the rake faces and egress area 129 forms
the remainder of the egress portion. The egress area 129 may be on
the same angle as the rake faces 124. The rake angle is negative
and is about -30.degree. to about -40.degree.. The egress faces 128
lead into the debris channel 114, 116. The rake faces 124 have a
substantial negative rake angle with the exception of some
percussive bits which are at 00. The edge radius 125, as can best
be seen in FIG. 11, is between the rake faces 124 and clearance
faces 126 and, as can be seen, is relatively dull and is on the
order of 0.004 to 0.008 inch as measured on some prior art
examples. However, in rotary only bits, while these bits may have
0.degree. rake angles, the edge radius is in the mentioned range.
Also, the rake face 124 and clearance face 126 define a cutting
angle between the two surfaces. The cutting angle is important for
chiseling action and is about 45.degree. to 110.degree.. Thus, with
the negative rake angle and the dull edge radius, the cutting tool
100, 102, as it rotates, glides inside the hole, synonymous to
spreading butter with a knife, smoothing away debris within the
hole. This requires substantial force to initiate cutting of the
hole in the concrete, aggregate or the like material.
66. In the double helix cutting tool 102, the chucking end 104' is
different from that of the single flute cutting tool 100 to
illustrate a rotary or percussive type chucking end. The tool
includes helixes 111 and 113 as well as flutes 115 and 117. As the
flutes end at the cutting head 106, the debris channels 114 and 116
are formed at the end of each of the flutes.
67. The cutting tip insert 118 is the same as that previously
described and the rake faces 124, cutting edge 120, clearance
surfaces 126 and first egress surface 128' and egress area 129' are
identified with the same numbers. However, the egress area 129' is
different than that in the single flute design. Here, the egress
area is parallel to the rake face. Also, the debris channels 114',
116' are substantially identical.
68. Both of these cutting tools illustrate a cutting tip having a
large obtuse included angle between the two cutting edges on the
order of 120.degree. to 130.degree.. Also, the egress angle,
ordinarily about 30.degree. to 35.degree., defining the plane of
the egress area is relatively shallow. Likewise, the clearance
angle, ordinarily about 20.degree. to 30.degree., which defines the
plane of the clearance surface is also shallow. Also a cutting
angle, between the rake face and clearance face, is ordinarily
about 90 to 110.
69. When defining angle measurement, the angles are true angles.
True angles are taken by defining a plane parallel to the center
line of the tool and through the cutting edge in an auxiliary view
with the cutting edge as a point. See FIGS. 5, 10, 16, 21. The rake
angle, designated by a, is the angle measured from the defined
plane to the rake face. The clearance angle, designated by CA, is
the complement of the angle measured from the defined plane to the
clearance face. The cutting angle, designated by .beta., is the
angle between the clearance face and rake face. The cutting angle
.beta. is equal to .alpha.+(90-CA). The egress angle, designated by
.lambda., is the angle from the defined plane to the egress face.
Positive rake angles are defined by clockwise rotation from a point
on the defined plane at the cutting edge to the rake face, when
viewed along the cutting edge from the outside diameter of the bit.
Negative rake angles are defined by counterclockwise rotation from
a point on the defined plane at the cutting edge to the rake face,
when viewed along the cutting edge from the outside diameter of the
bit.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
70. Turning to FIGS. 12 through 26, embodiments of the present
invention are shown. FIGS. 12 through 16 illustrate a single helix
design, designated with the reference numeral 200, and FIGS. 17
through 21 illustrate a double helix design, designated with the
reference numeral 300, respectively.
71. The single helix cutting tool 200 includes a chucking end 204,
in this particular case illustrated as a spline for a hammer
driver, however, a percussive and/or a cylindrical rotary end or
other attachment and drive means could be used. A cutting head 206
is at the other end of the cutting tool 200 and a shank 208 is
between the two ends. The helix 210 defines a flute 212. The flute
212 ends at the cutting head 206 into a debris channel or recess
214. Likewise, a second debris channel or recess 216 is cut into
the cutting head 206 opposing the recess 214.
72. The cutting head 206 includes an insert 218 which includes
cutting edge 220, rake faces 224, and clearance faces 226.
Likewise, egress faces 228 are immediately adjacent the rake faces
224.
73. The insert 218 has an overall pentagonal shape of a house with
the cutting edge 220 defining the roof, sides 230 and 232, and a
base 234 which is substantially perpendicular to the two parallel
sides 230 and 232. Also, the cutting edge could be along a straight
line to provide a rectangular insert, as seen in FIG. 29 and 30.
Here corresponding reference numerals are increased by 200. Thus,
the cutting tool is designated with the reference numeral 400. The
insert 218 is brazed, welded or the like into the slot 222 in the
cutting head 206. The insert 218 is generally manufactured from a
carbide material, such as carbide or tungsten carbide, however,
ceramics, ceramic composites, diamond dust, metal ceramic
composites or a unitary homogeneous or a deposit of layers could be
used. Also, the entire cutting tool could be manufactured from such
material or a portion thereof, including the head 206 manufactured
from such a material, eliminating the insert 218.
74. The cutting edges 220 are defined by rake faces 224, edge
radius 240 and the clearance faces 226. The cutting edges 220
include a primary cutting edge 236 and a secondary cutting edge
238. The primary cutting edge 236 is on an acute angle with respect
to the longitudinal axis 242, while the secondary cutting edge 238
is substantially perpendicular to the longitudinal axis 242.
75. The cutting edges 220 include edge radius 240 between the rake
faces 224 and clearance faces 226 (see FIG. 22). The edge radius
240 defines the sharpness of the cutting tool. An edge radius 240
of the present invention is generally between 0.0003 to 0.004 and
preferably between 0.0005 to 0.001. Having a desired edge radius
240 provides a desired sharpness to enable the cutting tool to cut
through the concrete, aggregate or the like material during
rotation of the cutting tool. The edge radius is formed by working,
such as by grinding or the like, the clearance face and the rake
face.
76. The two cutting edges 220 form a tip or point 221 between them.
The included angle (IA) between the two cutting edges 220 is from
about 90.degree. to 180.degree. and preferably about 100 to
160.
77. The cutting edges 220 are offset from the longitudinal axis 242
of the cutting tool 200. The rake faces 224 are worked or ground
into the insert and define rake angles .alpha. as defined above.
Generally, the rake angle .alpha. is between 10.degree. to
-10.degree., preferably at about 0.degree. for the primary cutting
edge portion 236. The rake angle is between -50.degree. to
-20.degree. preferably -40.degree. for the secondary cutting edge
portion 238. Thus, the worked rake surfaces are substantially
parallel to the longitudinal axis 242.
78. The rake faces 224 are formed by working, such as grinding or
the like, into both sides of the insert 218 and extend a desired
distance from the cutting edge 220. The distance or depth which the
rake faces 224, which are worked or ground into the insert, extend
from the cutting edge is known as the length of relief. The depth
of the length of relief is measured from the cutting edge 220 along
the longitudinal axis 242 to a first egress surface 244. The length
of relief of the rake faces 224 has a depth of about 0.08 to about
0.25 inch for a 3/4 inch diameter bit. Preferably, the depth is
from about 0.15 to about 0.25 inch. The length of relief can be
defined as a ratio with respect to the diameter of the tool. Thus,
the length of relief ratio is about 0.10 to about 0.32 inches per
inch diameter of the tool.
79. The first egress surface 244 angles from the terminus or end of
the length of relief. The first egress surface 244 is generally
angled with respect to the rake face 224, providing an overall
stepped cutting head, as seen in FIGS. 16 and 21. The angle of the
first egress surface 244 is from about 30.degree. to 90.degree. and
preferably 55.degree. to 60.degree. and may be continuous with and
at the same angle as the egress area 228.
80. The clearance surface 226, which includes a portion of the
insert 218 and the cutting head 206 define a clearance angle CA.
The clearance angle CA is defined as mentioned above. This
clearance angle is from about 10.degree. to about 50.degree. and
preferably about 20.degree. to 40.degree. for hammer and percussive
tools and 30.degree. to 50.degree. for rotary only tools.
81. A cutting angle .beta., as defined above, is defined between
the clearance face 226 and rake face 224. The cutting angle .beta.
is from about 30.degree. to 90.degree. and preferably from about
40.degree. to 60.degree. for the primary cutting edge portion. The
cutting angle for the secondary cutting edge portion varies from
60.degree. to 120.degree. preferably from 80.degree. to
100.degree.. These cutting angles define a primary cutting edge
portion which enhances cutting action, while the cutting angle
defined for the secondary cutting edge portion enhances the
chiseling action of the cutting tool.
82. The egress area 228 defines an egress angle .lambda. which is
measured as mentioned above. The egress area 228 is adjacent to the
first egress surface 244. The angle is at least 0.degree. and
preferably from about 30.degree. to 60.degree. for hammer and
percussive tools and at about -20.degree. to 90.degree. for rotary
only tools, preferably about -20.degree. to 20.degree. for hammer
and percussive tools and 45.degree. to 105.degree. for rotary only
tools. Also, the first egress surface 244' and egress area 228' may
be arcuate as seen in FIG. 28. Here they are shown on the same arc,
however, they could be on different arcs. This egress angle and
surface enhance the transport of debris from the tool tip into the
flute 212 of the shank 208. Thus, by providing a desired egress
angle, choking is prohibited at the cutting head 206. As seen in
FIGS. 12 through 16, a larger volume of material is removed from
the ball head enabling better debris removal.
83. Turning to FIGS. 17 to 21, the double helix embodiment of the
present invention is shown. The cutting tool 300 includes a chuck
end 304 which is a rotary or percussive type of cutting tool end.
Also, the helixes 307 and 309 and flutes 310 and 312 are different
from those previously described. The helixes 310 and 312 end at the
cutting head 306, thus enabling the debris recesses 314 and 316 to
include a larger volume of debris. The remaining portions of the
cutting head 306 are designated with reference numerals increased
by a hundred and the description is the same as in the first
embodiment since these elements are the same. The difference in the
head 306 in the egress area 328 and clearance surface 326 is due to
a reduced amount of material present in the double helix design
than is present in the single helix design. Otherwise, the angle
parameters previously described are the same with the double helix
design as they are with the single helix design.
84. Turning to FIGS. 23 through 27, the cutting tools of the
present invention are illustrated in concrete, aggregate or the
like material, boring a hole. When the terms concrete, aggregate or
the like material are used, the cutting tools may be used to bore,
but are not limited to, cap block, brick, stone, ceramic materials,
concrete, aggregate, black top, rock, cement, masonry or the like
materials. In drilling a hole using rotary only motion, the bit of
the present invention contacts the concrete, aggregate or the like
material. The cutting tool may be rotated only where the rake face
of the cutting tool cuts and bores a hole into the material.
Alternatively, the cutting tool contacts the concrete, aggregate or
the like material and impacts or chisels the material to form a
hole. Further, the cutting tool may contact the material and
impacting and rotating movement utilized together to bore a hole as
seen in FIG. 27. Generally, the impacting is sequential and
repetitious so that a constant repeating force is applied onto the
cutting tool. Also, when the cutting tool is purely rotational, a
constant force may be applied to the driver.
85. FIGS. 31 through 37 illustrate a double helix embodiment of the
present invention. Cutting tool 500 includes a chuck end 504 which
is a rotary or percussive type of cutting tool end. Also, the
helixes 507 and 509 and the flutes 510 and 512 are like those
previously described with respect to FIGS. 17 through 21. The
helixes 510 and 512 end at the cutting head 506, thus enabling the
debris recesses 514 and 516 to include a larger volume of
debris.
86. The cutting head 506 includes an insert 518 which includes
cutting edges 520, rake faces 524 and clearance faces 526.
Likewise, egress faces 528 are immediately adjacent the rake face
524.
87. The insert 518 has an overall pentagonal shape of a house with
the cutting edge 520 defining the roof, sides 530 and 532, and a
base 534, which is substantially perpendicular to the two parallel
sides 530 and 532. Also the cutting edges 520 could be along a
straight line to provide a rectangular insert as seen in FIGS. 29
and 30.
88. The insert 518 is braised, welded or the like into the slot 522
on the cutting head 506. The insert 518 is generally manufactured
from a carbide material such as a cobalt carbide mixture however,
ceramic, ceramic composites, diamond dust, metal ceramic composites
or a unitary homogeneous or a deposit of layers could be used.
89. Cutting edges 520 are defined by rake faces 524, edge radii 540
and clearance faces 526. The cutting edges 520 include a primary
cutting edge 536 and a secondary cutting edge 538. The primary
cutting edge 536 is on an acute angle with respect to a
longitudinal axis 542, while the secondary cutting edge 538 is
substantially perpendicular to the longitudinal axis 542. The
cutting edges 520 include edge radius 540 between the rake faces
524 and clearance faces 526 as seen in FIG. 36.
90. The edge radius 540 defines a sharpness of the cutting tool. An
edge radius 540 of the present invention is between 0.0015 to 0.004
and preferably between 0.002 to 0.003. Having a desired edge radius
540 provides a desired sharpness to enable the cutting tool to cut
through the concrete, aggregate or the like material during
rotation of the cutting tool. The edge radius as mentioned above is
formed during the powder pressing operation.
91. The included angle between the two cutting edges is like those
previously described. Also, the rake face angle .alpha. is between
10.degree. and 0.degree. preferably at about 5.degree.. However,
these angles are formed during the pressing operation. Also, the
angles of the primary and secondary cutting edge are similar to
those described above. The clearance angle CA as well as the
cutting angle .beta. are the same as those described above.
92. In this embodiment, a first egress surface is eliminated and an
egress area 528 is defined by an egress angle .lambda. which is
measured as mentioned above. The egress area 528 is adjacent to the
rake face 524. The angle is between 80.degree. and 100.degree. and
is preferably about 90.degree..
93. For a better understanding of molding the insert, refer to
FIGS. 38 through 41.
94. The insert 518 is illustrated with a clearance face 526, rake
faces 524 and a trailing face 525. The land 533 is formed between
the clearance face 524 and the trailing face 525. The width (X) of
the rake face 524, at the bottom of the insert, along the base 534
is wider than the width (Y) of the trailing face 525 such that an
angle B is formed along the land 533 with respect to the central
axis 559. The line extending from the land 533 is on an angle which
is counter clockwise away from the central axis. This angle enables
the insert to be removed from the mold.
95. Turning to FIG. 39, a mold and punch is illustrated. A V-shaped
punch 560 forms the roof of the insert 518 and an ejector pin 562,
in the mold 564, ejects the insert after it has been molded.
Powdered metal is poured into the mold 564 and the punch 560 is
inserted compressing the powder metal within the mold 564. Upon
compressing the powdered metal, as seen in FIG. 40, at the bottom
of the mold 564, the portion 568 of the mold 564 forming the rake
face 524 extends inward from the portion 570 of the mold 564 that
forms the trailing face 525. At the top of the mold 564, the width
of the molds are substantially the same as seen in FIG. 41. Thus,
when the insert 518 is ejected from the mold 564, since the bottom
portion of the rake face 524 is in an area as it exits the mold
which is wider than the rake face base portion of the insert 518,
the insert 518 is easily ejected from the mold 564. However, if the
angle B was clockwise with respect to the central axis 559, the
land would be formed in the opposite direction and the insert would
be jammed within the mold since the bottom of the insert would be
wider than the width of the top of the mold.
96. By having the punch 560 move axially with respect to the
insert, the desired rake faces 524 and clearance faces 526 as well
as the edge radii 540 are formed on the insert 518. The above
identified insert 518 forming is contrary to conventional molding
of positive rake carbide inserts, which moves a punch laterally or
perpendicular to the axis of the insert, to form the insert.
97. To manufacture a cutting tool in accordance with the invention,
ordinarily the tool would be made in methods consistent with those
in the art. To provide a tip with surfaces like those disclosed,
ordinarily the rake surfaces, egress surfaces and clearance
surfaces would be ground or formed by other conventional means into
the cutting tool to form the desired surfaces with desired
angles.
98. While the above detailed description describes the preferred
embodiment of the present invention, the invention is susceptible
to modification, variation, and alteration without deviating from
the scope and fair meaning of the subjoined claims.
* * * * *