U.S. patent application number 10/289543 was filed with the patent office on 2003-05-22 for method and fabricating tools for earth boring.
This patent application is currently assigned to Varel International, Inc.. Invention is credited to Cazalas, Yves, Cazaux, Bernard H., Cuillier, Bruno, Dourfaye, Alfazazi, Gallego, Gilles J-P, Pontneau, Bernard.
Application Number | 20030094730 10/289543 |
Document ID | / |
Family ID | 26965693 |
Filed Date | 2003-05-22 |
United States Patent
Application |
20030094730 |
Kind Code |
A1 |
Dourfaye, Alfazazi ; et
al. |
May 22, 2003 |
Method and fabricating tools for earth boring
Abstract
A method for creating a rapid prototype mold for parts of an
earth boring tool for manufacture thereof comprises initially
optimizing the drill bit design and integrating this design into
CAD code. The CAD code is utilized to generate a prototype file in
a computer outputting command signals to a laser, and a laser
scanner to prototype a mold utilizing stereolithography, selective
laser sintering, or laminated object manufacturing, in addition to
other prototype techniques to manufacture earth boring tool
parts.
Inventors: |
Dourfaye, Alfazazi; (Paris,
FR) ; Cazaux, Bernard H.; (Tarbes, FR) ;
Gallego, Gilles J-P; (Ibos, FR) ; Pontneau,
Bernard; (Pau, FR) ; Cuillier, Bruno; (Pau,
FR) ; Cazalas, Yves; (Tarbes, FR) |
Correspondence
Address: |
BAKER BOTTS L.L.P.
2001 ROSS AVENUE
SUITE 600
DALLAS
TX
75201-2980
US
|
Assignee: |
Varel International, Inc.
|
Family ID: |
26965693 |
Appl. No.: |
10/289543 |
Filed: |
November 6, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60346493 |
Nov 16, 2001 |
|
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|
Current U.S.
Class: |
264/219 ; 164/6;
264/109 |
Current CPC
Class: |
E21B 10/55 20130101;
B33Y 80/00 20141201; B22F 2998/10 20130101; B29C 64/153 20170801;
B22F 2999/00 20130101; Y02P 10/25 20151101; B29C 64/106 20170801;
B29C 64/135 20170801; B22F 2998/10 20130101; B22F 3/004 20130101;
B22F 1/142 20220101; B22F 2999/00 20130101; B22F 5/007 20130101;
B22F 10/20 20210101; B22F 2998/10 20130101; B22F 1/142 20220101;
B22F 3/004 20130101; B22F 2999/00 20130101; B22F 5/007 20130101;
B22F 10/18 20210101; B22F 2999/00 20130101; B22F 5/007 20130101;
B22F 10/12 20210101; B22F 2999/00 20130101; B22F 5/007 20130101;
B22F 10/28 20210101 |
Class at
Publication: |
264/219 ;
264/109; 164/6 |
International
Class: |
B22C 001/00 |
Claims
What is claimed is:
1. A method for fabricating components of an earth boring tool,
comprising: (a) creating a CAD database comprising a design of a
component of the tool; (b) prototyping a mold of the design of the
tool component from the created CAD database; (c) preparing the
mold for casting the tool component; and (d) filling the prepared
mold with a material selected for the tool component.
2. A method of fabricating a component of an earth boring tool as
set forth in claim 1 further comprising: repeating (a) through (d)
for each component of a tool.
3. The method of fabricating a component of an earth boring tool as
set forth in claim 1 further comprising firing the filled mold in a
furnace to solidify the selected material of the tool
component.
4. The method of fabricating a component of an earth boring tool as
set forth in claim 1 wherein filling the prepared mold comprises
filling the prepared mold with a molten metal.
5. The method of fabricating a component of an earth boring tool as
set forth in claim 1 wherein filling the prepared mold comprises
filling the mold with a nonmetallic material.
6. The method of fabricating a component of an earth boring tool as
set forth in claim 1 wherein filling the prepared mold comprises
filling the mold with a matrix powder with a binder.
7. A method of fabricating a component of an earth boring tool,
comprising: (a) optimizing a design of a tool component by
operation of a computer program; (b) integrating the optimized
design of the tool component into a CAD database; (c) prototyping a
mold of the design of the tool component from the integrated CAD
database; (d) preparing the mold for casting the tool component;
and (e) filling the prepared mold with a material selected for the
tool component.
8. The method of fabricating a component of an earth boring tool as
set forth in claim 7 further comprising repeating (a) through (e)
for each component of an earth boring tool.
9. The method of fabricating a component of an earth boring tool as
set forth in claim 7 wherein optimizing the design comprises
optimizing both the mechanical and hydraulic design of a tool
component.
10. The method of fabricating a component of an earth boring tool
as set forth in claim 7 further comprising firing the filled mold
in a furnace to solidify the selected material of the drill bit
component.
11. The method of fabricating a component of an earth boring tool
as set forth in claim 10 further comprising breaking away the
prepared mold to recover the molded tool component.
12. The method of fabricating a component of an earth boring tool
as set forth in claim 7 wherein prototyping a mold comprises
prototyping the mold by stereolithography.
13. The method of fabricating a component of an earth boring tool
as set forth in claim 7 wherein prototyping a mold comprises
prototyping by selective laser sintering.
14. The method of fabricating a component of an earth boring tool
as set forth in claim 7 wherein prototyping a mold comprises
prototyping by laminated object manufacturing.
15. The method of fabricating a component of an earth boring tool
as set forth in claim 7 wherein prototyping a mold comprises
prototyping by fused deposition modeling.
16. A method for creating a mold for components of a drill bit for
fabrication thereof, comprising: optimizing the design of a
component of a drill bit by operation of a computer program;
integrating the optimized design of the drill bit component into a
CAD database; and prototyping a mold of the drill bit component to
be fabricated in accordance with the optimized design.
17. The method for creating a mold of components of a drill bit as
set forth in claim 16 wherein prototyping a mold comprises
prototyping a male mold of the drill bit component.
18. The method for creating a mold for components of a drill bit as
set forth in claim 16 further comprising covering the prototyped
mold supported on a burnable pattern with a slurry of a hardenable
refractory material.
19. The method for creating a mold for components of a drill bit as
set forth in claim 18 further comprising hardening the refractory
material to form a shell.
20. The method for creating a mold for components of a drill bit as
set forth in claim 19 further comprising burning out the burnable
pattern and the prototype mold leaving the shell.
21. The method for creating a mold for components of a drill bit as
set forth in claim 20 further comprising filling the shell with a
material selected for the drill bit component.
22. The method for creating a mold for components of a drill bit as
set forth in claim 21 further comprising breaking away the shell to
release the molded drill bit component.
23. The method for creating a mold for components of a drill bit as
set forth in claim 16 wherein prototyping a mold comprises
prototyping a female mold of a drill bit component.
24. The method for creating a mold for components of a drill bit as
set forth in claim 23 further comprising creating a male master
mold from the prototyped female mold.
25. The method for creating a mold for components of a drill bit as
set forth in claim 24 further comprising creating a destructible
female mold from the male master mold.
26. The method for creating a mold for components of a drill bit as
set forth in claim 25 further comprising filling the destructible
female mold with a material selected for the drill bit
component.
27. A method for fabricating a component of a drill bit for earth
boring, comprising: optimizing the design of a drill bit component
by operation of a computer program; integrating the optimized
design into a CAD database comprising a design of the component of
the drill bit; generating a prototype file on the drill bit
comprising the CAD database; prototyping a mold of the drill bit
component from the prototype file; preparing the mold for casting
the drill bit component; and filling the prepared mold with a
material selected for the drill bit component.
28. The method of fabricating a component of a drill bit as set
forth in claim 27 wherein prototyping a mold comprises prototyping
a male mold of the drill bit components.
29. The method of fabricating a component of a drill bit as set
forth in claim 27 further comprising covering the mold supported on
a burnable pattern with a slurry of hardenable refractory
material.
30. The method of fabricating a component of a drill bit as set
forth in claim 29 further comprising hardening the refractory
material to form a shell.
31. The method of fabricating a component of a drill bit as set
forth in claim 30 further comprising burning out the burnable
pattern and the prototype mold leaving the shell.
32. The method of fabricating a component of a drill bit as set
forth in claim 31 wherein filling the prepared mold comprises
filling the shell with a material selected for the drill bit
component.
33. The method of fabricating a component of a drill bit as set
forth in claim 32 wherein filling the prepared mold further
comprises breaking away the shell to uncover the molded bit body
component.
34. The method of fabricating a component of a drill bit as set
forth in claim 27 wherein prototyping a mold comprises prototyping
a female mold of the drill bit component.
35. The method of fabricating a component of a drill bit as set
forth in claim 34 further comprising creating a male master mold
from the prototype female mold.
36. The method of fabricating a component of a drill bit as set
forth in claim 35 further comprising creating a destructible female
mold from the male master mold.
37. The method of fabricating a component of a drill bit as set
forth in claim 36 wherein filling the prepared mold comprises
filling the destructible female mold with a material selected for
the drill bit component.
Description
BACKGROUND OF THE INVENTION
[0001] Heretofore, earth boring tools were fabricated by a process
that started with a design of parts for the tool and then
painstakingly produce a prototype of each part and assemble the
parts into the desired tool. All this involved considerable time,
effort and expense and oftentimes the process had to be repeated
before an acceptable earth boring tool was ready for
production.
[0002] A present basic process for manufacturing tools for earth
boring, for example a drill bit, is to machine a solid billet of
steel into the desired final form of the bit body after the design
of the bit has been approved. An improvement in this basic process
is to cast the body of the bit into a form approximating the final
body form. This permitted a substantial reduction in machining from
the basic process and improved the production of tools for earth
boring considering both the time factor and the cost factor. The
casting process for the fabrication of tools is complicated by the
addition of the metal casting step, but the overall savings in time
and costs over the basic process are more than offset.
[0003] To fabricate a bit from a casting, a mold is prepared by
machining a cavity in a cylinder of graphite, reproducing a
negative of the bit profile in the exact dimensions of the body of
the bit. Cutting elements are located and the fluid passageways are
traced in the interior of the mold. Cutting elements and nozzle
openings, plus fluid circulation channels, are prepared from a
material destructible after firing of the mold in a furnace. The
various elements utilized in producing a mold are subsequently
destroyed after the casting process thereby resulting in a bit body
having shaped cutting element receptacles in the head of the
bit.
[0004] Recently, techniques have been developed for generating
three-dimensional objects within a fluid medium which is
selectively cured by beams of radiation brought to focus at
prescribed intersection points within the three-dimensional volume
of the fluid medium. These techniques utilize a process known as
"stereolithography" as a method for making solid objects by
successfully generating thin layers of a curable material one on
top of the other in response to a programmed movable beam of light
directed to a surface or layer of the curable liquid. Each layer
formed in the curable liquid is a solid cross section of the object
at the surface of the curable liquid. The process of generating
layers in cross section of an object is continued until the entire
object is formed in the curable liquid.
[0005] Use of stereolithography has become known as a "rapid
prototyping process." The first industries to utilize the rapid
prototyping process were manufacturers of aircraft modular units
that specialized in the design and manufacture of interior
components for military and commercial aircraft. Major applications
now include rapid prototyping and product tooling in the
automotive, aerospace, medical, computer, electronic and consumer
product industries. A leader in the field of rapid prototyping is
3D Systems Inc. of San Gabriel, Calif. 3D Systems Inc. has numerous
U.S. patents directed to various inventions relating to rapid
prototyping utilizing stereolithography.
[0006] A recent improvement in rapid prototyping in the manufacture
of products is the utilization of a CAD system that when combined
with rapid prototyping substantially reduces the time and cost of
bringing new products to market, reference is made to U.S. Pat. No.
5,544,550 issued Aug. 13, 1996, U.S. Pat. No. 6,200,514 B1 issued
Mar. 13, 2001, U.S. Pat. No. 6,209,420 B1 issued Apr. 3, 2001, and
British Patent No. GB 2,296,673.
[0007] However, there continues to be a need in the design and
production of tools for earth boring that rapidly and reliably
moves from a design stage to a prototype stage and ultimately the
fabrication of tools while moving directly from computer designs to
production and fabrication of finished tools.
[0008] Engineers and production managers in the earth boring
industries have long investigated and searched for rapid, reliable,
economical and automatic means to facilitate manufacture of tools
for earth boring moving from a design stage to the prototype stage
and to the production and fabrication, while avoiding the
complicated painstaking procedures utilized in the basic machine
process and the casting process described above.
SUMMARY OF THE INVENTION
[0009] The present invention is a method of fabricating a tool for
earth boring comprising creating a CAD data base of parts for a
desired tool. Utilizing the CAD data base, a prototype of molds of
the tool parts is fabricated. The mold is then prepared for casting
of the tool part, for example, a drill bit body. The prepared mold
is filled with a material selected for the drill bit body and the
filled mold is then processed into a tool part.
[0010] More specifically, after optimizing the design of the tool
parts by operation of a computer program that designs both
mechanical and fluid flow specification, the computed results are
integrated into a CAD code. A rapid. prototyping file is generated
and depending on the type of tool part to be manufactured, the file
contains either a female geometry of the tool parts. The
corresponding mold is then manufactured utilizing a rapid
prototyping process such as stereolithography, fretted metal by
laser, or strata of paper cut by laser.
[0011] Further, in accordance with the present invention, there is
provided a method for fabricating a component of a drill bit for
earth boring comprising creating a CAD data base comprising a
design of the component of the drill bit and then prototyping a
mold of the design of the drill bit component from the created CAD
database. The prototype mold is prepared for casting utilizing
either a male mold or a female mold, the latter considered a
"master-mold." Following preparation of the mold for casting, the
mold is filled with a material selected for the drill bit component
and the filled mold is fired in a furnace to solidify the selected
material into a component of the drill bit. Following preparation
of the mold for casting, the mold is filled with a molten material
and the selected material is solidified into a component of the
drill bit.
[0012] In accordance with the present invention, various tools for
earth boring may be fabricated using the rapid prototyping method.
Complex forms are easily created by using a computer to generate
the program commands as a CAD file that sends the signals to the
fabrication system. Although the invention will be described with
reference to fabrication of a drill bit for earth boring, it also
finds utility in the fabrication of other tools for earth
boring.
[0013] A technical advantage of the present invention is the
fabrication of earth boring tools using an efficient fabrication
process that saves considerable time, effort and expense. The
present invention also has the technical advantage of readily
modifying a tool design for specialized application that results in
improved cutting features. The parts fabricated in accordance with
the present invention are readily machined to a final specification
for fabrication into a complete tool for earth boring.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] For a more complete understanding of the present invention
and the advantages thereof, reference is now made to the following
description, taken in connection with the accompanying
drawings:
[0015] FIG. 1 is a top view of a steel body drag bit fabricated in
accordance with the process of the present invention;
[0016] FIG. 2 is a side view of the drag bit of FIG. 1;
[0017] FIG. 3 is a pictorial illustration of a system for
performing the process of the present invention;
[0018] FIG. 4 is a top level flowchart of the process for
manufacturing a drill bit for earth boring utilizing rapid
prototyping of a mold for the drill bit body;
[0019] FIG. 5 is a flowchart of one embodiment of the process of
the present invention for fabrication of a tool bit utilizing rapid
prototyping of a female mold;
[0020] FIG. 6 is a flowchart of an alternate embodiment of the
process of the present invention for manufacturing a drill bit
utilizing rapid prototyping of a female mold;
[0021] FIG. 7 is a flowchart of an alternate embodiment of the
process of the present invention for manufacturing a drill bit
utilizing rapid prototyping of a female mold;
[0022] FIG. 8 is a pictorial illustration of selective laser
sintering for rapid prototyping of molds for drill bit fabrication
in accordance with the process of the present invention; and
[0023] FIG. 9 is a pictorial illustration of a paper cut by laser
process for rapid prototyping a mold for the fabrication of a drill
bit body in accordance with the present invention.
DETAILED DESCRIPTION OF THE DRAWINGS
[0024] Referring to FIGS. 1 and 2, there is shown a drill bit body
10 fabricated in accordance with the rapid prototyping process of
the present invention. As illustrated, the bit body 10 includes
cavities for fixed cutters and is conventionally referred to in the
industry as a drag bit. It should be understood that the process of
the present invention is not limited to drag bits but finds utility
for other drill bits for earth boring and in addition for the
fabrication of other tools for earth boring.
[0025] As best illustrated in FIG. 2, the drill bit 10 comprises a
bit body 12, a shank 14 and a threaded connection or pin 16 for
connecting the drill bit to a sub or as part of a drill string (not
shown) in a manner conventional for drilling in formations of the
earth.
[0026] The bit body 12 includes a central longitudinal bore (not
shown) as is conventional with drill bit construction as a passage
for drilling fluid to flow through the drill string into the bit
body and exit through nozzles (not shown) arranged in the operating
end face 20. Extending radially from essentially the center of the
operating end face 20 are circumferentially spaced blades 22 that
extend down the side of the bit body 12 to the shank 14. The end of
the blades 22 at the shank 14 function as gauge pads. The bit body
12 is formed in accordance with the process of the present
invention typically utilizing powdered metal tungsten carbide (a
matrix bit body) or a molten metal casting process.
[0027] As best illustrated in FIG. 1, formed in each of the blades
22 of the bit body 12 is a pattern of pockets 24 that receive
primary cutting elements as is conventional in drag bit assembly.
The pockets 24 along with the passage for drilling fluid are
fabricated during the process of the present invention for
fabricating the bit body 12.
[0028] Referring to FIG. 3, there is pictorially illustrated a
stereolithographic system for generating complex geometry three
dimensional drill bit parts by creating a cross-sectional pattern
of the drill bit geometry at a surface of a fluid medium capable of
physical state alteration in response to appropriate synergistic
stimulation. A programmed movable spot beam of light from a laser
30 passing through a laser scanner 32 impinges on a surface or
layer of curable liquid in a photopolymer vat 34. The laser scanner
32, the photopolymer vat 34 and a Z-axis elevator 36 along with
controlling computers 38, 40 and 42, comprise together a
stereolithography system for creating complex geometry drill bit
parts. The stereolithography system of FIG. 3 represents a
technique to quickly make complex geometry drill bit parts without
conventional tooling.
[0029] To create the complex drill bit parts, a computer program is
run in the computer 42 to optimize a bit design including both
mechanical components and fluid passageways. This design is
integrated into a computer aided design (CAD) code in a computer
40. A rapid prototyping file is generated from the CAD code in a
computer 40. Depending on the type of bit to be manufactured, the
rapid prototyping file contains either the female or the male
geometry of the drill bit parts. The computer 38 then provides
drive signals to the laser 30, the laser scanner 32, and the Z-axis
elevator 36.
[0030] The stereolithographic system of FIG. 3 has many advantages
over currently used apparatus for producing complex geometry drill
bit parts. The system as illustrated in FIG. 3 minimizes the need
for producing design layouts and drawings and tooling drawings and
tooling. A drill bit engineer works directly with the computer 42
and the stereolithographic equipment of FIG. 3 and when satisfied
with the design of a drill bit part as displayed on the monitor of
the computer 42, a mold for the part is fabricated in the
photopolymer vat 34 for an immediate analysis and examination. If
the design requires modification, such modification is easily
accomplished through the computer 42 and another mold for a
prototyping part is fabricated to verify the change in a desired
drill bit design. Inasmuch as earth boring tools require many parts
with interacting functions, the method of rapid prototyping as
described herein becomes even more useful because all of the part
designs may be quickly changed and made again so that the total
assembly may be examined, repeatedly if necessary. After the design
is complete, part production begins immediately, weeks and months
between design and production are avoided.
[0031] As mentioned, depending on the type of bit to be
manufactured, the rapid prototyping file in the computer 38
contains either a female or a male mold geometry of the drill bit
parts. If the rapid prototyping file contains a female mold design,
this female mold as created in the photopolymer vat 34 is
subsequently utilized to manufacture a male former or used directly
to manufacture the bit. In the case of the direct use of the female
mold, the female former is filled and cured in a furnace for a
matrix body bit or the female former is filled with a molten metal
material in the case of a steel body bit.
[0032] If the rapid prototyping file contains a male mold design,
the rapid prototyping male mold from the photopolymer vat 34 is
mounted on a burnable pattern and the mold along with the burnable
pattern is covered with a slurry of hardenable, refractory
material. The coated pattern is placed in a dryer to harden the
refractory material to form a ceramic shell and simultaneously burn
out the burnable pattern and the rapid prototype female mold. The
resulting female former, preferably of a ceramic material, is
either placed in a supporting bed and filled with a molten metallic
material, or a matrix powder with a binder. For a matrix body bit,
the filled female former is cured in a furnace to create the
desired drill bit part. For a steel body bit, the ceramic mold is
filled with a molten steel to create the desired drill bit part.
After the molten metal has cooled to solidification, the ceramic
male former is broken away to expose the drill bit part having the
desired complex form.
[0033] Also by way of example, the rapid prototyping female mold
from the photo multiplier vat 34 is filled with a molten metallic
material or with a matrix powder and a binder. For a matrix body
bit, the filled female mold is cured in a furnace to create the
desired drill bit part. For a steel body bit, the female mold is
filled with a molten steel to create the desired drill bit part. In
either application, either the matrix body bit or the steel body
bit, after the material has solidified the female mold is broken
away to expose the drill bit part having the desired complex
form.
[0034] Alternatively, when the rapid prototyping file contains a
design for a female mold, the mold created is utilized to
manufacture a male former called a "master-mold." This master-mold
is then utilized to manufacture a destructible sand shell. The sand
shell is filled with the desired matrix and binder material and
placed in a furnace for hardening. For a steel body bit, the shell
is filled with a molten metal and allowed to harden.
[0035] Referring to FIG. 4, there is illustrated a flow diagram of
the process for manufacturing a drill bit utilizing the rapid
prototyping of a mold as illustrated and described with reference
to FIG. 3. Initially, by use of the computer 42, a designer
optimizes the drill bit design in a design operation 44. The
optimized drill bit design from operation 44 is integrated into CAD
code in the computer 40 by operation 46. The CAD code is then
utilized to generate a prototype file in the computer 38 in
operation 48. Output signals from the computer 38 utilizing the
prototype file actuate the laser 30, the laser scanner 32 and the
Z-axis elevator 36 to rapid prototype a mold for a drill bit part
in operation 50. When the rapid prototyping mold from operation 50
meets the design specification for a drill bit, the mold is used in
a conventional process to manufacture the drill bit part during
operation 52. The various parts of a drill bit are then assembled
into a fabricated drill bit of the type illustrated in FIGS. 1 and
2.
[0036] Referring to FIG. 5, there is illustrated a flow chart of
the process for creating a female mold from the rapid prototyping
system as illustrated in FIG. 3. As discussed with reference to
FIG. 4, initially the drill bit design is optimized in a CAD system
during operation 54. Utilizing the rapid prototyping file in the
computer 38, a rapid prototyping female mold is created in the
polymer vat 34 during operation 56. Utilizing the female mold
during an operation 62, the rapid prototyping mold is filled with a
molten metallic material for a steel bit body or with matrix powder
and binder. For a matrix powder and binder bit body, the filled
female mold is placed in a furnace during operation 64 to melt the
binder and infiltrate the matrix powder. Following operation 64 for
a matrix bit or following operation 62 for a steel body bit, the
material is cooled in a operation 66 and the rapid prototyping
female mold is broken away to expose the drill bit part having the
desired complex design.
[0037] Referring to FIG. 6, there is illustrated a flow diagram for
fabricating drill bit parts utilizing the rapid prototyping of a
female mold. As previously explained, initially the drill bit
design is optimized in a CAD system during operation 108. Utilizing
the stereolithography system of FIG. 3 a supple female mold is
rapid prototyped during operation 110. It should be noted that
other rapid prototyping processes can also be used such as
selective laser sintering (SLS), fused deposition modeling (FDM),
laminated object manufacturing (LOM), ballistic particle
manufacturing (BPM), and 3D printing.
[0038] After removing the rapid prototype mold from the
photopolymer vat 34, the mold is filled with a resilient material
in an operation 112 to produce a male former. The resilient
material in the female mold is dried during an operation 114 to
produce a male former. During an operation 116, the male former is
coated with a hardenable and refractory material in an operation
116 and the male former is removed leaving a resulting shell
mold.
[0039] The shell resulting from the operation 116 is filled with a
molten metallic material or with a matrix powder and binder in an
operation 118. For the matrix powder and binder, the filled shell
is placed in a furnace to melt the binder and infiltrate the matrix
powder during an operation 120. For a steel body bit and for the
matrix body bit, the last operation to fabricate a drill bit part
is completed in an operation 122.
[0040] Referring to FIG. 7, there is illustrated a flow diagram for
fabricating drill bit part utilizing the rapid prototyping of a
female mold. Again, initially the drill bit design is optimized in
a CAD system during operation 68. Utilizing the stereolithography
system of FIG. 3, the female mold is rapid prototyped during
operation 70. After removing the rapid prototype mold from the
photopolymer vat 34, the mold is filled with a resilient material
to produce a male pattern (master-mold) of the bit design during
operation 72. The resilient material in the female mold is dried
during an operation 74 to produce the master male former. During an
operation 76 the male former is coated with a mix of sand and resin
during operation 76. The mix of sand and resin is dried in an
operation 78 to produce a shell by removing the rapid prototyping
mold.
[0041] Following the operation 78, the process for manufacturing
drill bit parts using a female mold is the same as illustrated and
described with reference to FIG. 5 utilizing the described mold.
The shell produced by the operation 78 is filled with a metallic
material (a steel body bit) or with matrix powder and a binder in
an operation 80. For the matrix powder and binder (a matrix body
bit), the filled shell is placed in a furnace to melt the binder
and infiltrate the matrix powder during an operation 82. For a
steel body bit and, for the matrix body bit, the last operation to
fabricate a drill bit part is completed in operation 84.
[0042] It will be appreciated that other forms of appropriate
synergistic stimulation for a curable medium are available in
addition to the stereolithography system of FIG. 3. Referring to
FIG. 8, there is pictorially illustrated a process for selective
laser sintering (SLS) to create a rapid prototype mold for parts of
a drill bit. The drill bit design for use with the process of FIG.
8 is optimized by the computers 38, 40 and 42 as illustrated in
FIG. 3 and described with reference to FIG. 4. The output of the
computer 38 actuates a CO2 laser 86, a laser scanner 88 and a
precision roller mechanism 90. A layer of powder 92, for example, a
resin (polystyrene polycarbonates), a metallic or a ceramic, is
deposited in a powder bed 94. The powder is supplied from a powder
cartridge (not shown) typically contained within the housing 96.
The powder can be selected from other ceramic materials, such as,
alumina, zircon oxides (AL.sub.2O.sub.3, SiO.sub.2, ZrO.sub.2),
carbides (SiC, B.sub.4C and others), nitrous (Si.sub.3N.sub.4, AlN,
BN), or gains of these materials coated with a binder.
[0043] The precision roller mechanism 90, comprising a linearly
extending feedhead is horizontally moved across and above the
powder bed to spread a thin layer of powdered selective laser
sintering (SLS) material across the build platform. Using data from
the computer 38 the CO2 laser 86 in conjunction with the laser
scanner 88 selectively draws a cross section of the drill bit part
on the layer of powder in the powder bed 94. As the laser beam is
drawn across the section, it selectively "sinters" (heats and
fuses) the powder creating a solid mass that represents one cross
section of the drill bit mold part. Only the heated grains of the
powder participate in the development of the cross section with the
grains of powder surrounding the part acting to support the
following layers of the part being created by rapid
prototyping.
[0044] The process for creating a rapid prototype part utilizing
the selective laser sintering (SLS) system of FIG. 8 repeats the
process of spreading the powder by means of a precision roller
mechanism 90 and sintering layer after layer of the powder 92 until
the complete object is created. Once the part is completed, it is
removed from the build chamber of the housing 96 and any loose
powder is blown away. The rapid prototype mold created by the
system of FIG. 8 is then utilized to manufacture drill bit parts
the same as the molds created by the system of FIG. 3. Either a
female mold or a male mold will be created and drill bit parts
fabricated in accordance with the description of FIGS. 4, 5, 6, and
7. The selective laser sintering (SLS) process represents a
remarkable evolution in the rapid prototyping of three-dimensional
objects.
[0045] Another process for creating a rapid prototyping mold for
drill bit parts is a paper cut by laser process. Referring to FIG.
9, there is pictorially illustrated a laminated object
manufacturing (LOM) process for the formation of three dimensional
objects. A laser 100 and a laser scanner 102 receive command
signals from the computer 38 as illustrated in FIG. 3. The process
of FIG. 9 utilizes the rapid prototyping file resident in the
computer 38 resulting from optimizing a drill bit design by means
of the computer 42 and the computer 40 of FIG. 3.
[0046] In accordance with the laminated object manufacturing (LOM)
process, the system of FIG. 9 deposits layers of "thermal-adhesive"
paper on a platen support 104 and these pieces of paper are cut by
the light beam emitting from the laser 100 in a pattern as
determined by positioning of the X-Y laser scanner 102. Each layer
of paper deposited on the platen 104 forms a cross section of the
three-dimensional object created by the laminated object
manufacturing (LOM) process. Upon completion of cutting of one
layer of paper, an additional layer is placed on the platen 104
from a supply roll 106. This process of cutting the deposited layer
of paper by means of the laser 100 as controlled by the X-Y laser
scanner 102 continues until a compact block of paper is supported
on the platen 104. As illustrated in FIG. 9, a three-dimensional
object, e.g., a mold for a drill bit part, is in the center of the
compact block of paper on the platen 104. It is therefore necessary
to clear the cutting surrounding the object to reveal the mold for
manufacture of drill bit parts.
[0047] The resulting mold from operation of the system of FIG. 9 is
either a female mold or a male mold as previously described. These
molds are utilized in accordance with the processes of FIGS. 4, 5,
6 and 7 to fabricate drill bit parts in accordance with an
optimized design. For a more complete description of the laminated
object manufacturing (LOM) process, reference is made to U.S. Pat.
No. 4,752,352, issued Jun. 21, 1998, and U.S. Pat. No. 5,015,312
issued May 14, 1991, and PCT publication WO 95/18009 published Jul.
6, 1995.
[0048] It will be understood from the foregoing that, although
particular embodiments of the invention have been illustrated and
described, various modifications can be made without the departing
from the invention as set forth in the appended claims.
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