CA2072302C - Rock drill bit and method of making same - Google Patents
Rock drill bit and method of making sameInfo
- Publication number
- CA2072302C CA2072302C CA002072302A CA2072302A CA2072302C CA 2072302 C CA2072302 C CA 2072302C CA 002072302 A CA002072302 A CA 002072302A CA 2072302 A CA2072302 A CA 2072302A CA 2072302 C CA2072302 C CA 2072302C
- Authority
- CA
- Canada
- Prior art keywords
- shank
- head
- tip
- recess
- cutter
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
- 239000011435 rock Substances 0.000 title claims abstract description 17
- 238000004519 manufacturing process Methods 0.000 title claims description 7
- 238000005520 cutting process Methods 0.000 claims abstract description 13
- 238000001816 cooling Methods 0.000 claims abstract description 5
- 238000000034 method Methods 0.000 claims description 22
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 12
- 229910000831 Steel Inorganic materials 0.000 claims description 9
- 239000010959 steel Substances 0.000 claims description 9
- 239000012530 fluid Substances 0.000 claims description 7
- 229910052757 nitrogen Inorganic materials 0.000 claims description 6
- 239000007788 liquid Substances 0.000 claims description 5
- 230000006698 induction Effects 0.000 claims description 4
- 238000012544 monitoring process Methods 0.000 claims description 3
- 241000277275 Oncorhynchus mykiss Species 0.000 claims 2
- 238000010438 heat treatment Methods 0.000 claims 2
- 238000007654 immersion Methods 0.000 claims 1
- 239000000314 lubricant Substances 0.000 claims 1
- 239000000463 material Substances 0.000 description 7
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 6
- 229910052759 nickel Inorganic materials 0.000 description 3
- 229910000851 Alloy steel Inorganic materials 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 229910000617 Mangalloy Inorganic materials 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 230000008602 contraction Effects 0.000 description 1
- 238000005553 drilling Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000001788 irregular Effects 0.000 description 1
- 238000003754 machining Methods 0.000 description 1
- 238000005498 polishing Methods 0.000 description 1
- 238000009877 rendering Methods 0.000 description 1
- 238000005482 strain hardening Methods 0.000 description 1
- UONOETXJSWQNOL-UHFFFAOYSA-N tungsten carbide Chemical compound [W+]#[C-] UONOETXJSWQNOL-UHFFFAOYSA-N 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23P—METAL-WORKING NOT OTHERWISE PROVIDED FOR; COMBINED OPERATIONS; UNIVERSAL MACHINE TOOLS
- B23P11/00—Connecting or disconnecting metal parts or objects by metal-working techniques not otherwise provided for
- B23P11/02—Connecting or disconnecting metal parts or objects by metal-working techniques not otherwise provided for by first expanding and then shrinking or vice versa, e.g. by using pressure fluids; by making force fits
- B23P11/025—Connecting or disconnecting metal parts or objects by metal-working techniques not otherwise provided for by first expanding and then shrinking or vice versa, e.g. by using pressure fluids; by making force fits by using heat or cold
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B10/00—Drill bits
- E21B10/62—Drill bits characterised by parts, e.g. cutting elements, which are detachable or adjustable
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B17/00—Drilling rods or pipes; Flexible drill strings; Kellies; Drill collars; Sucker rods; Cables; Casings; Tubings
- E21B17/02—Couplings; joints
- E21B17/04—Couplings; joints between rod or the like and bit or between rod and rod or the like
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/49826—Assembling or joining
- Y10T29/49863—Assembling or joining with prestressing of part
- Y10T29/49865—Assembling or joining with prestressing of part by temperature differential [e.g., shrink fit]
Abstract
A rock drill bit having a shank and a replaceable cutting head, comprising steps of producing a shank having a tip with an outer surface having a given shape, producing a head having a working face at one end and a recess at the other end with a cross-section corresponding in shape to that of the shank tip, and having a size .15% less than that of the shank tip, cooling the shank in a cryogenic gas at ambient pressure to reduce its size, installing the head on the shank tip, and permitting the components to return to ambient temperature, to establish a shrink fit between the head and the shank.
Description
207230~2 This invention relates generally to rock drills and more particularly to a rock drill bit. The invention is also directed to a method of securing a removable head on the shank of a bit.
All rock drill bits comprise two parts --a head and a shank--which may or may not be integral. The function of the head is to break rock and to direct bits of broken rock away from the work face. Typically, tungsten carbide buttons or chisels permanently inserted into the working face of the head perform the breaking function. The head material must be tough and wear-resistant to withstand continual hammering and the abrasive effects of broken rock. Suitable head materials include through-hardening tool steels such as A2, A8 and D2; through-hardening alloy steel containing at least 1.8% nickel; work-hardening steels such as Hadfield steel, or case-hardening steels containing .15% to .25%
carbon and at least 1.8% nickel. These materials have preferred characteristics, but other materials may be used instead. The shank's function is primarily to transfer percussive energy from a hammer to the head of the bit. The bit is also rotated in use, so some:torque may be developed as well. Suitable materials for the shank may contain 1.8% or more nickel.
If the head and the shank of a bit can be made separately, then the best material for each may be selected, based on technical and economic requirements. Furthermore, the diameter of stock material used to make each component may be selected for that component alone, reducing scrap and costs. It remains to join the head to the shank in a way that retains the head with enough force so that it does not come off the shank in use, while permitting the head to be removed without damaging either part, particularly the shank. This of course rules out welding and other permanent bonding methods. If the components are designed for a press fit, the resulting union is not reliable under the hammering the bit takes in use. Furthermore, heavy press fits would damage the surfaces of the components, possibly rendering the shank unsuitable for re-use.
~, 20723~2 .
We have found that shrink fitting is a particularly suitable method of assembly, particularly when the parts have non-uniform cross-sections, and have developed methods for assembling and disassembling drill bit components having a .15% interference fit.
An object of this invention is to produce rock drill bits having improved life and performance.
Another object is to lower manufacturing costs for drill bits, by reducing required inventories, and by simplifying bit assembly.
A related object is to reduce the consumption of resources, by minimizing waste during manufacture, and by reducing the frequency of shank disposal.
These and other objects are met by a method of making a rock drill bit having a shank and a replaceable cutting head, comprising steps of producing a shank having a tip with an outer surface, producing a head having a working face at one end and a recess at the other end with a cross-section corresponding in shape to that of said shank tip, and having a size in the range of .012% - .38%
less than that of said shank tip, cooling said shank in liquid nitrogen or other cryogenic fluid to reduce its size, installing said heàd on said shank tip, and permitting the components to return to ambient temperature, to establish a shrink fit between the head and the shank.
In the accompanying drawings;
Figure 1 is an exploded elevational view, in partial section, of a drill bit embodying the invention, showing the two components of the bit relatively positioned for assembly;
Figure 2 is a view corresponding to Figure 1, showing the parts assembled;
Figure 3 is an enlarged sectional view thereof, taken along a plane 3-3 perpendicular to the axis of the bit;
Figures 4-7 show non-circular shapes of alternative forms of the invention; and, Figure 8 is a diagrammatic view, in partial section, of a device for disassembling the bit.
As shown in Figure 1, a rock drill bit embodying the invention comprises a generally cylindrical steel shank 10 having a tip 12 terminating at a cutter end face 14 perpendicular to the axis 16 of the shank. The side surfaces 18 of the shank tip are preferably perpendicular to this end face within fourteen seconds that is, substantially free of taper. Alternately, however, the tip could have a slight reverse taper (i.e., slightly larger at its end), to better retain the cutter head. The tip, whose diameter is shown slightly greater than that of the rest of the shank to facilitate machining and polishing operations, preferably has a surface finish in the range of 30 to 50 microinches. A through bore 20 extends along the axis from the cutter end face 14 to the driving end face 22 (Fig. 8); this bore passes drilling fluids normally, as also receives liquid nitrogen during the disassembly procedure discussed further below.
A cutter head 30 to be installed on the shank tip includes a generally cylindrical body 32 substantially larger in diameter than the shank. The cutting face 34 of the head has conventional hardened cutting elements 36 installed in its surface, near the periphery 38 thereof. The cutter face depicted has plural holes 40 (at least one such hole is required) which pass through the body, converging toward the tool axis. The holes terminate at a 2~72302 recess 42 formed in the rear of the head. The recess has a shape like that of the shank tip, and has a preferred surface finish in the 30 to 50 microinch range. The side 44 of the recess are preferably perpendicular to its bottom surface 46, within fourteen seconds, to insure full contact with the shank when assembled. The depth of the recess is selected based on the strength requirements of the union; obviously, a deeper recess produces a stronger joint.
To maximize strength, the bottom of the recess is radiused or chamfered, and the tip is correspondingly radiused or chamfered to avoid interference at the corners.
The recess and the shank tip may both be cylindrical, that is circular in cross-section; however, to provide additional security against relative rotation between the parts, it is preferred that the cross-section by non-circular. Non-circularity can be in the form of a keyway or dowelway 48, shown in Figure 3, or both parts can have oval or polygonal cross-sections, as shown in Figures 4-7.
The shank is .012% to .38% bigger in cross-sectional size than the recess into which it fits, so that there is substantial interference. By "size" we mean diameter, where the cross-sectional shape is substantially circular, or width where the shape is poly~onal or irregular. An interference fit of .15% may render it impossible to press the components together, particularly since the cutter elements are subject to damage, as it is desired to re-use at least the shanks. Therefore, the parts are preferably assembled by shrink fitting. One way of achieving a shrink fit is to immerse the shank, for a period of time, in liquid nitrogen, which boils at -321F.
At -300F, the linear coefficient of expansion of steel is .0000054; thus cooling it from room temperature to below 300F
produces a shrinkage of .2%, well more than the .15%
interference. Once cooled, the shank can be inserted quickly into, and bottomed in, the recess. When the parts have returned to ambient temperature, they are firmly united, without having been subjected to any mechanical force application that could have produced visible damage or unseen cracks.
The tool is then placed in service. When the cutter elements have become worn, the bit is removed from service, and returned for renewing. There is no need to dispose of the entire bit, because the wear on the shank is significantly less than that on the head, on the order to two to three times less. Therefore, the shank can be re-used once or twice; however, it is necessary first to remove the worn cutter head. Attempting to pull the components apart mechanically is apt to damage the shank so that it cannot be reused. Therefore, a differential thermal shrinkage process is used to disassemble the parts. This process is somewhat more difficult, since the components are in intimate thermal contact.
However, we have found a way to achieve sufficient differential thermal contraction to permit the parts to be pulled apart with at most a light press. In practicing this method, the bit is placed in a fixture 50 (Figure 8) with the cutter head 30 down. A seal 52 is then inserted in the bottom of the through hole, and iiquid nitrogen 54 is poured into the hole. As the shank cools, its temperature is monitored, at a point just adjacent the cutter head.
When the temperature of the shank at that point has fallen to below -100F, or preferably further, the cutter head is rapidly heated by an electric induction device 56. A suitable unit is an induction furnace produced by Westinghouse, under model no. MFC-2, which has its own sensor for monitoring the temperature of the shank. Sufficient thermal differential is achieved to permit the parts to be easily pulled apart by hydraulic cylinders 58.
It will be appreciated by those of skill in this art that in the assembly procedure, it would be possible to heat the head, rather than cooling the shank, to achieve the requisite temperature differential, and such a variation is intended to be embraced by the invention.
It will be appreciated that a cryogenic fluid other than liquid nitrogen could be used with this invention; hence the claims, that follow use the generic term.
All rock drill bits comprise two parts --a head and a shank--which may or may not be integral. The function of the head is to break rock and to direct bits of broken rock away from the work face. Typically, tungsten carbide buttons or chisels permanently inserted into the working face of the head perform the breaking function. The head material must be tough and wear-resistant to withstand continual hammering and the abrasive effects of broken rock. Suitable head materials include through-hardening tool steels such as A2, A8 and D2; through-hardening alloy steel containing at least 1.8% nickel; work-hardening steels such as Hadfield steel, or case-hardening steels containing .15% to .25%
carbon and at least 1.8% nickel. These materials have preferred characteristics, but other materials may be used instead. The shank's function is primarily to transfer percussive energy from a hammer to the head of the bit. The bit is also rotated in use, so some:torque may be developed as well. Suitable materials for the shank may contain 1.8% or more nickel.
If the head and the shank of a bit can be made separately, then the best material for each may be selected, based on technical and economic requirements. Furthermore, the diameter of stock material used to make each component may be selected for that component alone, reducing scrap and costs. It remains to join the head to the shank in a way that retains the head with enough force so that it does not come off the shank in use, while permitting the head to be removed without damaging either part, particularly the shank. This of course rules out welding and other permanent bonding methods. If the components are designed for a press fit, the resulting union is not reliable under the hammering the bit takes in use. Furthermore, heavy press fits would damage the surfaces of the components, possibly rendering the shank unsuitable for re-use.
~, 20723~2 .
We have found that shrink fitting is a particularly suitable method of assembly, particularly when the parts have non-uniform cross-sections, and have developed methods for assembling and disassembling drill bit components having a .15% interference fit.
An object of this invention is to produce rock drill bits having improved life and performance.
Another object is to lower manufacturing costs for drill bits, by reducing required inventories, and by simplifying bit assembly.
A related object is to reduce the consumption of resources, by minimizing waste during manufacture, and by reducing the frequency of shank disposal.
These and other objects are met by a method of making a rock drill bit having a shank and a replaceable cutting head, comprising steps of producing a shank having a tip with an outer surface, producing a head having a working face at one end and a recess at the other end with a cross-section corresponding in shape to that of said shank tip, and having a size in the range of .012% - .38%
less than that of said shank tip, cooling said shank in liquid nitrogen or other cryogenic fluid to reduce its size, installing said heàd on said shank tip, and permitting the components to return to ambient temperature, to establish a shrink fit between the head and the shank.
In the accompanying drawings;
Figure 1 is an exploded elevational view, in partial section, of a drill bit embodying the invention, showing the two components of the bit relatively positioned for assembly;
Figure 2 is a view corresponding to Figure 1, showing the parts assembled;
Figure 3 is an enlarged sectional view thereof, taken along a plane 3-3 perpendicular to the axis of the bit;
Figures 4-7 show non-circular shapes of alternative forms of the invention; and, Figure 8 is a diagrammatic view, in partial section, of a device for disassembling the bit.
As shown in Figure 1, a rock drill bit embodying the invention comprises a generally cylindrical steel shank 10 having a tip 12 terminating at a cutter end face 14 perpendicular to the axis 16 of the shank. The side surfaces 18 of the shank tip are preferably perpendicular to this end face within fourteen seconds that is, substantially free of taper. Alternately, however, the tip could have a slight reverse taper (i.e., slightly larger at its end), to better retain the cutter head. The tip, whose diameter is shown slightly greater than that of the rest of the shank to facilitate machining and polishing operations, preferably has a surface finish in the range of 30 to 50 microinches. A through bore 20 extends along the axis from the cutter end face 14 to the driving end face 22 (Fig. 8); this bore passes drilling fluids normally, as also receives liquid nitrogen during the disassembly procedure discussed further below.
A cutter head 30 to be installed on the shank tip includes a generally cylindrical body 32 substantially larger in diameter than the shank. The cutting face 34 of the head has conventional hardened cutting elements 36 installed in its surface, near the periphery 38 thereof. The cutter face depicted has plural holes 40 (at least one such hole is required) which pass through the body, converging toward the tool axis. The holes terminate at a 2~72302 recess 42 formed in the rear of the head. The recess has a shape like that of the shank tip, and has a preferred surface finish in the 30 to 50 microinch range. The side 44 of the recess are preferably perpendicular to its bottom surface 46, within fourteen seconds, to insure full contact with the shank when assembled. The depth of the recess is selected based on the strength requirements of the union; obviously, a deeper recess produces a stronger joint.
To maximize strength, the bottom of the recess is radiused or chamfered, and the tip is correspondingly radiused or chamfered to avoid interference at the corners.
The recess and the shank tip may both be cylindrical, that is circular in cross-section; however, to provide additional security against relative rotation between the parts, it is preferred that the cross-section by non-circular. Non-circularity can be in the form of a keyway or dowelway 48, shown in Figure 3, or both parts can have oval or polygonal cross-sections, as shown in Figures 4-7.
The shank is .012% to .38% bigger in cross-sectional size than the recess into which it fits, so that there is substantial interference. By "size" we mean diameter, where the cross-sectional shape is substantially circular, or width where the shape is poly~onal or irregular. An interference fit of .15% may render it impossible to press the components together, particularly since the cutter elements are subject to damage, as it is desired to re-use at least the shanks. Therefore, the parts are preferably assembled by shrink fitting. One way of achieving a shrink fit is to immerse the shank, for a period of time, in liquid nitrogen, which boils at -321F.
At -300F, the linear coefficient of expansion of steel is .0000054; thus cooling it from room temperature to below 300F
produces a shrinkage of .2%, well more than the .15%
interference. Once cooled, the shank can be inserted quickly into, and bottomed in, the recess. When the parts have returned to ambient temperature, they are firmly united, without having been subjected to any mechanical force application that could have produced visible damage or unseen cracks.
The tool is then placed in service. When the cutter elements have become worn, the bit is removed from service, and returned for renewing. There is no need to dispose of the entire bit, because the wear on the shank is significantly less than that on the head, on the order to two to three times less. Therefore, the shank can be re-used once or twice; however, it is necessary first to remove the worn cutter head. Attempting to pull the components apart mechanically is apt to damage the shank so that it cannot be reused. Therefore, a differential thermal shrinkage process is used to disassemble the parts. This process is somewhat more difficult, since the components are in intimate thermal contact.
However, we have found a way to achieve sufficient differential thermal contraction to permit the parts to be pulled apart with at most a light press. In practicing this method, the bit is placed in a fixture 50 (Figure 8) with the cutter head 30 down. A seal 52 is then inserted in the bottom of the through hole, and iiquid nitrogen 54 is poured into the hole. As the shank cools, its temperature is monitored, at a point just adjacent the cutter head.
When the temperature of the shank at that point has fallen to below -100F, or preferably further, the cutter head is rapidly heated by an electric induction device 56. A suitable unit is an induction furnace produced by Westinghouse, under model no. MFC-2, which has its own sensor for monitoring the temperature of the shank. Sufficient thermal differential is achieved to permit the parts to be easily pulled apart by hydraulic cylinders 58.
It will be appreciated by those of skill in this art that in the assembly procedure, it would be possible to heat the head, rather than cooling the shank, to achieve the requisite temperature differential, and such a variation is intended to be embraced by the invention.
It will be appreciated that a cryogenic fluid other than liquid nitrogen could be used with this invention; hence the claims, that follow use the generic term.
Claims (19)
1. A method of making a rock drill bit having a shank and a replaceable cutting head, comprising steps of producing a steel shank having a tip with an outer surface having a predetermined cross-sectional shape, producing a steel head having a working face at one end and a recess at the other end with a cross-section corresponding in shape to that of said shank tip, and having a size at least in the range of .012% to .38% less than that of said shank tip when the components are at the same temperature, cooling said shank with a cryogenic fluid to reduce its size to less than that of said recess, installing said head on said shank tip, and permitting the components to return to ambient temperature, to establish a shrink fit between the head and the shank.
2. The method of claim 1, wherein the shank tip outer surface, and the inner surface of the head recess, each have a surface finish in the range of 30 to 50 microinches.
3. The invention of claim 1, wherein the shank tip and head recess have corresponding non-circular cross sectional shapes.
4. The invention of claim 1, wherein the shank tip and head recess are both free of surface lubricants during assembly.
5. The invention of claim 1, wherein the size of said recess is .15% less than that of said shank tip before the components are assembled.
6. A rock drill bit, having a shank and a replaceable cutting head, produced by the method of claim 1.
7. A method of disassembling a rock drill bit having a hollow shank and separate head which has been shrunk fit onto the shank, comprising steps of securing the shank in a fixture, filling the shank with a cryogenic fluid to reduce its size, monitoring the temperature of the shank adjacent the head, when said temperature is reduced to -100°F, heating the head rapidly with an electric induction coil to expand the head, and then pulling the head off of the shank.
8. A method of making a rock drill bit having as components a shank and a replaceable cutting head, comprising steps of producing a steel shank having a tip with an outer surface of a predetermined cross-sectional shape, producing a steel head having a working face at one end and a recess at the other end with a cross-sectional corresponding in shape to that of said shank tip, and having a size at least .15%
less than that of said shank tip.
changing the temperature of at least one of said components, to make the temperature of the shank sufficiently less than that of the head that the shank tip fits freely within said recess, installing said head on said shank tip, and permitting the components to return to ambient temperature, to establish a shrink fit between the head and the shank.
less than that of said shank tip.
changing the temperature of at least one of said components, to make the temperature of the shank sufficiently less than that of the head that the shank tip fits freely within said recess, installing said head on said shank tip, and permitting the components to return to ambient temperature, to establish a shrink fit between the head and the shank.
9. A method of making a rock drill bit having a shank and a replaceable cutting head, comprising steps of:
producing a steel shank for transferring percussive energy from a hammer to the cutting head, said shank having a driving end face and a shank tip having a cutter end face, a through bore extending through an axis of the shank between said driving end face and said cutter end face, said tip having side walls substantially perpendicular to said cutter end face, said tip having predetermined cross-sectional shape and diameter;
producing a cutter head having a cutter face impregnated with hardened cutting elements, said cutter head having a recess opposite said cutter face, a through hole from said cutter face to said recess, said recess having a cross-sectional shape corresponding to the cross-sectional shape of said shank tip and having a diameter in the range of 0.012% to 0.38% less than the diameter of said shank tip when at substantially equal temperature with the shank tip;
developing a temperature difference between the cutter head and the shank tip such that the shank tip has a diameter less than that of said recess;
inserting said shank tip within said recess; and, equalizing temperatures of the cutter head and the shank tip to establish a secure attachment of the cutter head on the steel shank.
producing a steel shank for transferring percussive energy from a hammer to the cutting head, said shank having a driving end face and a shank tip having a cutter end face, a through bore extending through an axis of the shank between said driving end face and said cutter end face, said tip having side walls substantially perpendicular to said cutter end face, said tip having predetermined cross-sectional shape and diameter;
producing a cutter head having a cutter face impregnated with hardened cutting elements, said cutter head having a recess opposite said cutter face, a through hole from said cutter face to said recess, said recess having a cross-sectional shape corresponding to the cross-sectional shape of said shank tip and having a diameter in the range of 0.012% to 0.38% less than the diameter of said shank tip when at substantially equal temperature with the shank tip;
developing a temperature difference between the cutter head and the shank tip such that the shank tip has a diameter less than that of said recess;
inserting said shank tip within said recess; and, equalizing temperatures of the cutter head and the shank tip to establish a secure attachment of the cutter head on the steel shank.
10. The method of claim 9, wherein the temperature difference is developed by cooling the shank tip.
11. The method of claim 9 wherein the shank tip has an outer surface and said recess has an inner surface, each of said shank tip outer surface and recess inner surface having finishes in the range of 30 to 50 microinches.
12. The method of claim 9 wherein the at-rest diameter of said recess is 0.15% less than the diameter of said shank tip when the cutting head and shank tip are at the same temperature.
13. the method of claim 9, wherein the at-rest diameter of said recess is 0.15% less than the diameter of said shank tip when the cutting head and shank tip are at the same temperature.
14. A rock drill bit, having a shank and a replaceable cutting head, produced by the method of claim 9.
15. The method of claim 10 wherein the shank tip is cooled by immersion in liquid nitrogen.
16. The method of claim 10 wherein the shank tip is cooled to at least -320°F.
17. The method of claim 10 further comprising the steps of:
securing the shank in a fixture;
filling the shank with a cryogenic fluid to reduce its size;
monitoring the temperature of the shank tip;
heating the cutter head rapidly by using an electric induction coil to expand the cutter head when the monitored temperature of the shank tip is reduced to at least -100°F;
pulling the cutter head from the shank tip.
securing the shank in a fixture;
filling the shank with a cryogenic fluid to reduce its size;
monitoring the temperature of the shank tip;
heating the cutter head rapidly by using an electric induction coil to expand the cutter head when the monitored temperature of the shank tip is reduced to at least -100°F;
pulling the cutter head from the shank tip.
18. The method of claim 17 further comprising the step of placing a seal within the shank bore substantially at the cutter end face to seal the bore from the through hole of the cutter head to prevent cryogenic fluid from entering the cutter head.
19. The method of claim 17 wherein the cutter head is pulled from the shank tip using hydraulic cylinders.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US07/721,767 US5150636A (en) | 1991-06-28 | 1991-06-28 | Rock drill bit and method of making same |
| US721,767 | 1991-06-28 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2072302A1 CA2072302A1 (en) | 1992-12-29 |
| CA2072302C true CA2072302C (en) | 1995-05-09 |
Family
ID=24899230
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002072302A Expired - Fee Related CA2072302C (en) | 1991-06-28 | 1992-06-25 | Rock drill bit and method of making same |
Country Status (10)
| Country | Link |
|---|---|
| US (1) | US5150636A (en) |
| JP (1) | JPH0711857A (en) |
| CN (1) | CN1027768C (en) |
| AU (1) | AU655474B2 (en) |
| BR (1) | BR9202493A (en) |
| CA (1) | CA2072302C (en) |
| DE (1) | DE4220846A1 (en) |
| MX (1) | MX9203650A (en) |
| SE (1) | SE9201947L (en) |
| ZA (1) | ZA924698B (en) |
Families Citing this family (58)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SE506207C2 (en) * | 1992-01-22 | 1997-11-24 | Sandvik Ab | Lower Drill |
| US5560440A (en) * | 1993-02-12 | 1996-10-01 | Baker Hughes Incorporated | Bit for subterranean drilling fabricated from separately-formed major components |
| US5441121A (en) * | 1993-12-22 | 1995-08-15 | Baker Hughes, Inc. | Earth boring drill bit with shell supporting an external drilling surface |
| US6230822B1 (en) * | 1995-02-16 | 2001-05-15 | Baker Hughes Incorporated | Method and apparatus for monitoring and recording of the operating condition of a downhole drill bit during drilling operations |
| US5687792A (en) * | 1995-09-27 | 1997-11-18 | Baker Hughes Incorporated | Drill pipe float valve and method of manufacture |
| US5974877A (en) * | 1996-05-01 | 1999-11-02 | Food Engineering Corporation | Sight window assembly and method of forming same |
| CN1059850C (en) * | 1997-04-09 | 2000-12-27 | 郑安明 | Method for precision hot-forging mine drill bit |
| US5975816A (en) * | 1997-07-09 | 1999-11-02 | Cook; Harold D. | Harmonic dampener for rotary tool holder |
| WO1999002297A1 (en) * | 1997-07-09 | 1999-01-21 | Cook Harold D | Machine tool extension and method of forming the same |
| CA2233433C (en) * | 1998-03-27 | 2007-07-31 | Mold-Masters Limited | Injection molding cylindrical manifold insert and method |
| US6220117B1 (en) | 1998-08-18 | 2001-04-24 | Baker Hughes Incorporated | Methods of high temperature infiltration of drill bits and infiltrating binder |
| EP1144797B1 (en) | 1998-11-23 | 2005-07-27 | Oy Atlas Copco Rotex Ab | A method for mounting a casing shoe on a drilling apparatus |
| US6161309A (en) * | 1999-04-28 | 2000-12-19 | Cook; Harold D. | Heat shrink tool holder cooler |
| US6234729B1 (en) | 1999-04-28 | 2001-05-22 | Harold D. Cook | Shrink fit shoulder interface |
| US6109842A (en) * | 1999-08-03 | 2000-08-29 | Cook; Harold D. | Tool holder with harmonic dampening drive mechanism |
| DE19936008B4 (en) * | 1999-08-04 | 2014-01-09 | Krohne Ag | Method for attaching a metal body to a measuring tube of a Coriolis mass flowmeter |
| CA2323270A1 (en) * | 1999-10-15 | 2001-04-15 | William A. Koegler | Paper drill bit |
| SE9904752A (en) * | 1999-12-22 | 2000-01-24 | Sandvik Ab | Toolholder and insert arrangement with a shrink fit coupling |
| SE516524C2 (en) * | 2000-05-18 | 2002-01-22 | Sandvik Ab | Utilities Connection |
| SE516501C2 (en) | 2000-05-18 | 2002-01-22 | Sandvik Ab | Utilities Connection |
| US6766870B2 (en) * | 2002-08-21 | 2004-07-27 | Baker Hughes Incorporated | Mechanically shaped hardfacing cutting/wear structures |
| GB2400146B (en) * | 2003-03-31 | 2005-03-02 | Minebea Co Ltd | A method of swaging a spherical bearing |
| US7077608B2 (en) * | 2004-04-22 | 2006-07-18 | Parlec, Inc. | System for mounting a machine tool in a holder |
| US7472764B2 (en) * | 2005-03-25 | 2009-01-06 | Baker Hughes Incorporated | Rotary drill bit shank, rotary drill bits so equipped, and methods of manufacture |
| US7419017B2 (en) * | 2005-06-10 | 2008-09-02 | Keystone Drill Services, Inc. | Multi-sectional percussive drill bit assembly |
| US7776256B2 (en) * | 2005-11-10 | 2010-08-17 | Baker Huges Incorporated | Earth-boring rotary drill bits and methods of manufacturing earth-boring rotary drill bits having particle-matrix composite bit bodies |
| US7703555B2 (en) | 2005-09-09 | 2010-04-27 | Baker Hughes Incorporated | Drilling tools having hardfacing with nickel-based matrix materials and hard particles |
| US7597159B2 (en) | 2005-09-09 | 2009-10-06 | Baker Hughes Incorporated | Drill bits and drilling tools including abrasive wear-resistant materials |
| US7997359B2 (en) | 2005-09-09 | 2011-08-16 | Baker Hughes Incorporated | Abrasive wear-resistant hardfacing materials, drill bits and drilling tools including abrasive wear-resistant hardfacing materials |
| US8002052B2 (en) * | 2005-09-09 | 2011-08-23 | Baker Hughes Incorporated | Particle-matrix composite drill bits with hardfacing |
| US7784567B2 (en) * | 2005-11-10 | 2010-08-31 | Baker Hughes Incorporated | Earth-boring rotary drill bits including bit bodies comprising reinforced titanium or titanium-based alloy matrix materials, and methods for forming such bits |
| US7913779B2 (en) | 2005-11-10 | 2011-03-29 | Baker Hughes Incorporated | Earth-boring rotary drill bits including bit bodies having boron carbide particles in aluminum or aluminum-based alloy matrix materials, and methods for forming such bits |
| US7807099B2 (en) * | 2005-11-10 | 2010-10-05 | Baker Hughes Incorporated | Method for forming earth-boring tools comprising silicon carbide composite materials |
| US8770324B2 (en) * | 2008-06-10 | 2014-07-08 | Baker Hughes Incorporated | Earth-boring tools including sinterbonded components and partially formed tools configured to be sinterbonded |
| US7802495B2 (en) | 2005-11-10 | 2010-09-28 | Baker Hughes Incorporated | Methods of forming earth-boring rotary drill bits |
| US7395883B2 (en) * | 2005-12-15 | 2008-07-08 | Rockmore International, Inc. | Keyed connection for drill bit |
| DE102006000081A1 (en) * | 2006-02-20 | 2007-08-23 | Hilti Ag | rock drill |
| EP2066864A1 (en) | 2006-08-30 | 2009-06-10 | Baker Hughes Incorporated | Methods for applying wear-resistant material to exterior surfaces of earth-boring tools and resulting structures |
| US7775287B2 (en) | 2006-12-12 | 2010-08-17 | Baker Hughes Incorporated | Methods of attaching a shank to a body of an earth-boring drilling tool, and tools formed by such methods |
| US7841259B2 (en) | 2006-12-27 | 2010-11-30 | Baker Hughes Incorporated | Methods of forming bit bodies |
| US20090155010A1 (en) * | 2007-12-17 | 2009-06-18 | Cook Harold D | Tool holder dampening system |
| JP4398497B2 (en) * | 2007-10-12 | 2010-01-13 | 株式会社丸和技研 | Waste melting furnace slag outlet opening bit |
| US20090308662A1 (en) * | 2008-06-11 | 2009-12-17 | Lyons Nicholas J | Method of selectively adapting material properties across a rock bit cone |
| US8261632B2 (en) | 2008-07-09 | 2012-09-11 | Baker Hughes Incorporated | Methods of forming earth-boring drill bits |
| US20120145464A1 (en) * | 2009-08-05 | 2012-06-14 | Gien Bernard L | Bit assembly for a down-the-hole hammer drill |
| DE102009049451B3 (en) * | 2009-10-14 | 2011-03-03 | Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. | Clamping element for shrink tensioning of bodies of drilling tool, has circular joint element that is arranged between base body and closed tension ring and is fixed to both base and tensioning ring |
| US9028009B2 (en) | 2010-01-20 | 2015-05-12 | Element Six Gmbh | Pick tool and method for making same |
| GB201000869D0 (en) * | 2010-01-20 | 2010-03-10 | Element Six Holding Gmbh | Superhard pick tool and method for making same |
| US20130243541A1 (en) * | 2012-03-14 | 2013-09-19 | Techniks, Inc. | Combined thermal fit and rotational locking machine tool assembly |
| EP2900408A2 (en) | 2012-09-28 | 2015-08-05 | Element Six GmbH | Pick tool having a super-hard planar strike surface |
| US9970238B2 (en) | 2013-07-26 | 2018-05-15 | Oy Atlas Copco Rotex Ab | Method in putting together of a down-the-hole drilling apparatus and a down-the-hole drilling apparatus |
| US9487927B1 (en) | 2014-01-13 | 2016-11-08 | Michael Stebbins | Impact tool |
| CN105201411A (en) * | 2015-10-19 | 2015-12-30 | 无锡市永亿精密铸造有限公司 | Drill bit containing graphite cone |
| US10113424B2 (en) | 2016-01-13 | 2018-10-30 | Caterpillar Paving Products Inc. | Milling tool holder |
| US10167720B2 (en) | 2016-01-13 | 2019-01-01 | Caterpillar Paving Products Inc. | Milling tool holder |
| US10184336B2 (en) | 2016-01-13 | 2019-01-22 | Caterpillar Paving Products Inc. | Milling tool holder |
| CN108907297A (en) * | 2018-07-18 | 2018-11-30 | 佛山市蓝瑞欧特信息服务有限公司 | A kind of cold and hot drill bit |
| US11053741B1 (en) | 2020-06-05 | 2021-07-06 | Weatherford Technology Holdings, Llc | Sidetrack assembly with replacement mill head for open hole whipstock |
Family Cites Families (25)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA906381A (en) * | 1972-08-01 | B. Kast Howard | Interference fits by heat treatment | |
| US1426637A (en) * | 1921-11-21 | 1922-08-22 | Arthur L Hawkesworth | Drill |
| US1692966A (en) * | 1927-09-13 | 1928-11-27 | Treiber Diesel Engine Corp | Method of uniting metal objects |
| US1955728A (en) * | 1932-04-09 | 1934-04-24 | Colony Man Corp | Chilling method and tool for expansion fits |
| US2535320A (en) * | 1944-04-07 | 1950-12-26 | Chicago Pneumatic Tool Co | Tool joint |
| US2479698A (en) * | 1944-08-26 | 1949-08-23 | Weatherhead Co | Rock drill |
| US2757906A (en) * | 1949-05-05 | 1956-08-07 | Atlas Copco Ab | Means for drilling in rock or the like |
| US2620686A (en) * | 1949-07-30 | 1952-12-09 | Reed Roller Bit Co | Method of mounting a cutter upon earth boring bits |
| US2757007A (en) * | 1953-05-29 | 1956-07-31 | Delaware Tool Steel Corp | Shank and bushing assembly for pneumatic tools |
| US3213951A (en) * | 1963-05-16 | 1965-10-26 | Edwin G Eeles | Rock drill with socket having a curved surface |
| GB1111593A (en) * | 1964-09-25 | 1968-05-01 | Nat Res Dev | Improvements in or relating to the securing of sleeves in cylinder bores |
| US3304816A (en) * | 1965-04-07 | 1967-02-21 | Louis C Galorneau | Detachable drill tip and coupling means |
| US3655244A (en) * | 1970-07-30 | 1972-04-11 | Int Tool Sales | Impact driven tool with replaceable cutting point |
| US4019590A (en) * | 1975-03-03 | 1977-04-26 | Carmet Company | Method of roof drilling |
| US4157122A (en) * | 1977-06-22 | 1979-06-05 | Morris William A | Rotary earth boring drill and method of assembly thereof |
| US4190125A (en) * | 1977-11-09 | 1980-02-26 | Fansteel Inc. | Drill bit and steel combination for improved fluid flow |
| US4361196A (en) * | 1980-07-11 | 1982-11-30 | Carmet Company | Roof bit coupling |
| US4406336A (en) * | 1981-02-09 | 1983-09-27 | Olsen John K | Drilling bit |
| US4405074A (en) * | 1981-08-31 | 1983-09-20 | Kulicke And Soffa Industries Inc. | Composite bonding tool and method of making same |
| US4427082A (en) * | 1982-02-08 | 1984-01-24 | Gte Laboratories, Inc. | Mining drill |
| US4462148A (en) * | 1982-03-18 | 1984-07-31 | Dana Corporation | Method of axial retention of gear on shaft |
| US4631973A (en) * | 1983-03-09 | 1986-12-30 | Dana Corporation | Axial retention of gear on shaft |
| US4632195A (en) * | 1985-06-03 | 1986-12-30 | Fansteel Inc. | Roof drill system |
| SE457623B (en) * | 1987-04-21 | 1989-01-16 | Sandvik Ab | TOOL CONNECTION |
| US4783893A (en) * | 1987-09-04 | 1988-11-15 | Robert Farino | Method of removing a head from a golf club |
-
1991
- 1991-06-28 US US07/721,767 patent/US5150636A/en not_active Expired - Fee Related
-
1992
- 1992-06-24 SE SE9201947A patent/SE9201947L/en not_active Application Discontinuation
- 1992-06-24 AU AU18625/92A patent/AU655474B2/en not_active Ceased
- 1992-06-25 DE DE4220846A patent/DE4220846A1/en not_active Withdrawn
- 1992-06-25 ZA ZA924698A patent/ZA924698B/en unknown
- 1992-06-25 CA CA002072302A patent/CA2072302C/en not_active Expired - Fee Related
- 1992-06-26 MX MX9203650A patent/MX9203650A/en unknown
- 1992-06-27 CN CN92108830A patent/CN1027768C/en not_active Expired - Fee Related
- 1992-06-29 JP JP4192746A patent/JPH0711857A/en active Pending
- 1992-07-07 BR BR929202493A patent/BR9202493A/en not_active Application Discontinuation
Also Published As
| Publication number | Publication date |
|---|---|
| ZA924698B (en) | 1993-08-09 |
| BR9202493A (en) | 1993-02-09 |
| US5150636A (en) | 1992-09-29 |
| SE9201947L (en) | 1992-12-29 |
| CN1074267A (en) | 1993-07-14 |
| CA2072302A1 (en) | 1992-12-29 |
| MX9203650A (en) | 1993-12-01 |
| JPH0711857A (en) | 1995-01-13 |
| CN1027768C (en) | 1995-03-01 |
| AU1862592A (en) | 1993-01-07 |
| DE4220846A1 (en) | 1993-01-14 |
| AU655474B2 (en) | 1994-12-22 |
| SE9201947D0 (en) | 1992-06-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA2072302C (en) | Rock drill bit and method of making same | |
| US5423719A (en) | Abrasive tools | |
| US5251964A (en) | Cutting bit mount having carbide inserts and method for mounting the same | |
| US4277869A (en) | Stabilizer | |
| EP1163424B1 (en) | Cutting tool holder assembly | |
| US3807804A (en) | Impacting tool with tungsten carbide insert tip | |
| EP1232320B1 (en) | A method for the manufacturing of a drill bit for percussive rock drilling and a rock drill bit and buttons therefor | |
| US4817852A (en) | Method of replacing drill bit heads | |
| US20090184564A1 (en) | Pcd percussion drill bit | |
| CA2247842A1 (en) | Shank adapter | |
| CA2259090A1 (en) | Rock drill | |
| WO2001049460A1 (en) | Composite tool and method of manufacture | |
| US6095266A (en) | Drill rod and method for its manufacturer | |
| EP0200476B1 (en) | Improvements in or relating to rotary drill bits | |
| KR20210094084A (en) | Tool assembly for friction stir welding | |
| HU221837B1 (en) | Tool and method for the manufacture of it | |
| EP1010486B1 (en) | Interference fit type cutting tool | |
| US5588497A (en) | Mounting drill buttons | |
| US5569002A (en) | Hollow annular drill bit with hollow cylindrical carrier member | |
| US20010029634A1 (en) | Tool for setting drop-in anchors | |
| US5746281A (en) | Method for mounting hard metal buttons in a drill bit | |
| US3852874A (en) | Method of inserting buttons in a drilling head | |
| JP5360532B2 (en) | Carbide tool and manufacturing method thereof | |
| US5988301A (en) | Drill rod and method for its manufacture | |
| WO2001083934A2 (en) | Method for the manufacturing of a cone cutter for rotary drilling by crushing, a rotary cone drill bit, a cone cutter and crushing elements therefore |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| MKLA | Lapsed |