CA2312100A1 - Grinding cup for drill bits - Google Patents
Grinding cup for drill bits Download PDFInfo
- Publication number
- CA2312100A1 CA2312100A1 CA 2312100 CA2312100A CA2312100A1 CA 2312100 A1 CA2312100 A1 CA 2312100A1 CA 2312100 CA2312100 CA 2312100 CA 2312100 A CA2312100 A CA 2312100A CA 2312100 A1 CA2312100 A1 CA 2312100A1
- Authority
- CA
- Canada
- Prior art keywords
- grinding
- grinding cup
- cup
- drive shaft
- cavity
- 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.)
- Abandoned
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B24—GRINDING; POLISHING
- B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
- B24B3/00—Sharpening cutting edges, e.g. of tools; Accessories therefor, e.g. for holding the tools
- B24B3/24—Sharpening cutting edges, e.g. of tools; Accessories therefor, e.g. for holding the tools of drills
- B24B3/33—Sharpening cutting edges, e.g. of tools; Accessories therefor, e.g. for holding the tools of drills of drills for stone
Abstract
A grinding cup for detachable connection to a draft shaft of a grinding machine for grinding buttons on drill bits comprises top and bottom surfaces, and a lower grinding section having a centrally disposed recess formed in the bottom surface of the grinding cup and having the desired profile for the button to be ground; wherein the periphery of the lower grinding section comprises a series of reinforcing ribs extending longitudinally towards the top surface; and wherein the peripheral edge of the bottom surface is bevelled to facilitate, during grinding, the removal of cutting fluid and steel from the face of the bit around the button through the spaces between the ribs; and comprising an upper body section having a centrally disposed cavity formed in the top surface of the grinding cup, said cavity being shaped and sized to permit the drive shaft of the grinding machine to fit snuggly within the cavity without retaining means. The cavity may further comprise a non-metal liner adapted to receive the drive shaft and to absorb vibrations generated between the drive shaft and the grinding cup during grinding operations.
Description
v s GRINDING CUP FOR DRILL BITS
Background to the Invention This invention relates to grinding cups used to refurbish or reprofile drill bits.
In particular, the grinding cup is for use in association with hammer bits which are typically tungsten-carbide bits driven by a rotary tool powered by pneumatic or hydraulic means, intended for drilling rock.
It is commonly known to use non-circular, solid drive shafts which fit into tools with corresponding non-circular openings in order to create rotary motion for the operation of various tools and bits. Typically, in the field of grinding cups used to refurbish hammer bits, a steel drive shaft contacts a steel, or steel-diamond matrix, grinding cup in order to transmit motion from the drive shaft to the grinding cup.
Grinding cups have a leading surface which is recessed and profiled to match the ideal profile of the multiple tungsten-carbide buttons located on the face of a drill bit. Such buttons may be hemispherical, parabolic or conical (bullet-shaped) in profile. When a rotating grinding cup is placed over such buttons, the grinding action generated by the grinding cup reprofiles the buttons from a somewhat flattened or distorted shape to a more ideal, rounded shape.
Problems can arise during reprofiling of drill bits as a result of this direct contact between two hard surfaces, namely the drive shaft and the grinding cup to which the drive shaft imparts rotary motion. In order to make the grinding cup fit easily onto a drive shaft, some clearance must be left between the drive shaft and the grinding cup. In operation, vibration between the two parts results. This can create r discomfort or potential injury to the worker holding the pneumatically or hydraulically driven tool. Moreover, the vibration may damage the surfaces of both the drive shaft and the grinding cup. Since this vibration and hard contact tends to generate heat, and cause the metal parts to expand to some degree, the parts may lock when heated unless sufficient clearance is provided. As discussed above, however, the more the clearance, the greater the vibration problem. In some cases, the profile of the drive shaft or of the grinding cup in contact therewith can be distorted and/or stripped as a result of the clearance and vibration problem.
In addition, when pressure is applied by the operator in the direction of the drill bit being reprofiled, the stress on the forward edge, or crown, of the grinding cup can be significant. On occasion, the crown of a grinding cup can chip around its periphery. Moreover, when the forward end of the grinding cup contacts the surface of a drill bit, the escape of steel shavings created by the cutting action of the grinding cup, and of the coolant fluid typically used to facilitate the cutting action and keep the grinding cup and work piece cool during operation, can be impeded.
Typically, as set out above, one or more passageways is provided from the grinding tool through the grinding cup for flow of cutting fluid to the drill bit face to assist in the grinding operation. In some prior grinding cups, the opening to allow escape of this coolant fluid from the grinding cup to the working surface is centrally disposed in the front end of the grinding cup. When a circular opening is located centrally in the grinding cup, the grinding cup may create an undesired bump or nipple on the leading surface of the drill bit button being ground.
Background to the Invention This invention relates to grinding cups used to refurbish or reprofile drill bits.
In particular, the grinding cup is for use in association with hammer bits which are typically tungsten-carbide bits driven by a rotary tool powered by pneumatic or hydraulic means, intended for drilling rock.
It is commonly known to use non-circular, solid drive shafts which fit into tools with corresponding non-circular openings in order to create rotary motion for the operation of various tools and bits. Typically, in the field of grinding cups used to refurbish hammer bits, a steel drive shaft contacts a steel, or steel-diamond matrix, grinding cup in order to transmit motion from the drive shaft to the grinding cup.
Grinding cups have a leading surface which is recessed and profiled to match the ideal profile of the multiple tungsten-carbide buttons located on the face of a drill bit. Such buttons may be hemispherical, parabolic or conical (bullet-shaped) in profile. When a rotating grinding cup is placed over such buttons, the grinding action generated by the grinding cup reprofiles the buttons from a somewhat flattened or distorted shape to a more ideal, rounded shape.
Problems can arise during reprofiling of drill bits as a result of this direct contact between two hard surfaces, namely the drive shaft and the grinding cup to which the drive shaft imparts rotary motion. In order to make the grinding cup fit easily onto a drive shaft, some clearance must be left between the drive shaft and the grinding cup. In operation, vibration between the two parts results. This can create r discomfort or potential injury to the worker holding the pneumatically or hydraulically driven tool. Moreover, the vibration may damage the surfaces of both the drive shaft and the grinding cup. Since this vibration and hard contact tends to generate heat, and cause the metal parts to expand to some degree, the parts may lock when heated unless sufficient clearance is provided. As discussed above, however, the more the clearance, the greater the vibration problem. In some cases, the profile of the drive shaft or of the grinding cup in contact therewith can be distorted and/or stripped as a result of the clearance and vibration problem.
In addition, when pressure is applied by the operator in the direction of the drill bit being reprofiled, the stress on the forward edge, or crown, of the grinding cup can be significant. On occasion, the crown of a grinding cup can chip around its periphery. Moreover, when the forward end of the grinding cup contacts the surface of a drill bit, the escape of steel shavings created by the cutting action of the grinding cup, and of the coolant fluid typically used to facilitate the cutting action and keep the grinding cup and work piece cool during operation, can be impeded.
Typically, as set out above, one or more passageways is provided from the grinding tool through the grinding cup for flow of cutting fluid to the drill bit face to assist in the grinding operation. In some prior grinding cups, the opening to allow escape of this coolant fluid from the grinding cup to the working surface is centrally disposed in the front end of the grinding cup. When a circular opening is located centrally in the grinding cup, the grinding cup may create an undesired bump or nipple on the leading surface of the drill bit button being ground.
Summary of the Invention Accordingly, it would be an advantage to provide a grinding cup with means for reducing the vibration between the grinding cup and the drive shaft of the grinding tool. In addition, it would be an advantage to provide means for strengthening the periphery of the forward crown end of the grinding cup to prevent peripheral chipping. In addition, it would be an advantage to provide means to permit steel shavings and coolant to escape from the forward end of the grinding cup more easily and to permit a wider cut of steel around the button of the drill bit being profiled.
Moreover, it would be an advantage to provide a grinding cup which is conformed so as to prevent the formation of bumps or nipples on the leading end of the drill bit buttons being ground.
The instant invention overcomes these problems in the prior art.
In a major aspect of the invention, a grinding cup for detachable connection to a drive shaft of a grinding machine for grinding buttons on drill bits comprises top and bottom surfaces, and a lower grinding section having a centrally disposed recess formed in the bottom surface of the grinding cup, and having the desired profile for the button to be ground, wherein the periphery of the lower grinding section comprises a series of reinforcing ribs extending longitudinally towards the bottom surface thereof, and wherein the peripheral edge of the bottom surface is bevelled to facilitate during grinding the removal of cutting fluid and steel from the face of the bit around the button, through the spaces between the ribs, said grinding cup further comprising an upper body section having a centrally disposed cavity formed in the top surface of the grinding cup, said cavity being shaped and sized to permit the drive shaft of the grinding machine to fit snugly within the cavity without retaining means.
In further aspects of the invention, the cavity further comprises a non-metal liner adapted to receive the drive shaft and to absorb vibrations generated between the drive shaft and the grinding cup during grinding operations.
In further aspects of the invention:
(a) The non-metal liner comprises artificial rubber, a thermoplastic material, or a carbon-based composite material;
(b) A single passageway connects the top and bottom surfaces of the grinding cup to permit a coolant to be provided to the surface of the button during grinding;
(c) The centrally disposed recess in the bottom surface of the grinding cup comprises multiple slots radiating from the centre of the surface, but not joining at said centre;
(d) The multiple slots comprise three slots each disposed at an angle of 60° to the adjacent slots;
(e) The grinding cup comprises a material capable of grinding tungsten-carbide button bits;
-$-(f) The grinding cup comprises a steel and diamond matrix.
Further aspects of the invention will become apparent from the following description of an illustrative embodiment of the invention.
$
Brief Description of the Drawings An illustrative embodiment of the invention is shown in the following drawings in which:
Figure 1 A is a perspective view of the grinding cup illustrating the cavity in the upper end of the cup;
Figure 1 B is a plan, elevation view of the grinding cup of the invention;
Figure 1 C is a perspective view of the grinding cup illustrating the recess in the lower 1$ end of the cup;
Figure 2A is a plan, cross-sectional, elevation view of a first embodiment of the grinding cup illustrating the vibration damping liner;
Figure 2B is a plan, cross-sectional, elevation view of a first embodiment of the vibration damping liner;
Figure 2C is a lower, end view of the grinding cup illustrating a first embodiment of the vibration damping liner;
Figure 3A is a plan, cross-sectional, elevation view of a second embodiment of the grinding cup illustrating the vibration damping liner;
Figure 3B is a plan, cross-sectional, elevation view of a second embodiment of the vibration damping liner;
Figure 3C is a lower, end view of the grinding cup illustrating a second embodiment of the vibration damping liner;
Figure 4A is a plan, cross-sectional, elevation view of a third embodiment of the grinding cup illustrating the vibration damping liner;
Figure 4B is a plan, cross-sectional, elevation view of a third embodiment of the vibration damping liner;
Figure 4C is a lower, end view of the grinding cup illustrating a third embodiment of the vibration damping liner;
Figure SA is a plan, cross-sectional, elevation view of a fourth embodiment of the grinding cup illustrating the vibration damping liner;
Figure SB is a plan, cross-sectional, elevation view of a fourth embodiment of the vibration damping liner;
Figure SC is a lower, end view of the grinding cup illustrating a fourth embodiment of the vibration damping liner;
Figure 6 is an upper, end view of the grinding cup illustrating the ribs and slots.
Detailed Description of the Invention Refernng to Figures 1 A, 1 B and 1 C, a grinding cup 1 having an upper end 3 and a lower end 5 comprises a hard material. Typically, the grinding cup, or at least the grinding portion thereof, comprises steel or a steel - diamond matrix.
Running longitudinally and located adjacent the lower end 5 of the grinding cup, are a series of ribs 7 lying around the perimeter of lower end S. The leading edge 9 of the lower end 5 is bevelled towards said perimeter and the upper end 3 of the grinding cup 1 to assist in removal of cutting fluid and cuttings from the drill bit button being reprofiled. The ribs 7 extend substantially to the leading edge of lower end 5. These _7_ ribs provide reinforcement to the leading edge of lower end 5 and prevent chipping of the grinding cup in this area. The spaces between the ribs 7 also provide areas where cutting fluid and cuttings may more easily pass. Moreover, the ribs widen the cutting area around each drill bit button, thus clearing away burrs which can develop at the base of such buttons using conventional grinding cups. This leads to cleaner button profiles.
Refernng to Figure 6, the leading lower end 5 of grinding cup 1 is illustrated in end view. Ribs 7 are spaced evenly around the perimeter of the crown 11 and extend at least to the leading end of bevelled surface 9. A series of slots 13 radiating from the centre of the grinding cup 1, but not joining at the centre, provide grinding and cutting action as the grinding cup rotates about the button being reproflled.
Cutting fluid flows through these slots to assist in keeping the work piece cool.
Since the slots do not join at the centre, and thus there is no opening at the centre of the grinding cup, no bump or nipple is formed at the centre of the button.
Refernng to Figure 2A, the grinding cup 1 typically comprises steel. The crown 11 maybe comprised of steel or a steel diamond matrix. A recessed opening in the lower end of the grinding cup provides a grinding surface 15 which is profiled to conform to the shape and size of the drill bit button being reprofiled. The recess may be concave, parabolic or conical (bullet-shaped) depending on the shape of the drill bit buttons to be reprofiled.
A channel 17 running along the longitudinal axis of the grinding cup conducts drilling fluid or coolant from a coolant source (not shown) to the button being reprofiled. Such coolant supplies are well-known in the art.
-$_ At the upper end 3 of the grinding cup is an opening or cavity 19 profiled slightly larger than the corresponding profile of the drive shaft 20 of the rotary tool to be inserted into the grinding cup in order to impart rotary motion to the grinding cup. Only that portion of the drive shaft which fits into the cavity is illustrated.
S
Figure 2B illustrates a non-metal liner 21 adapted to be snug-fit and, optionally, fixed with some adhesive or vulcanized, into cavity 19 located in the upper end of grinding cup 1. The exterior wall 23 of said liner contacts the surfaces of the grinding cup 1 adjacent the upper end 3 which define the cavity 19. The inner surface 25 of the liner is sized and profiled to fit snugly around the drive shaft 20 of the grinding tool. These features are also illustrated in Figure 2C, an end view of the upper end of the grinding cup.
Three alternative embodiments of the grinding cup with different non-metal liners are illustrated respectively in Figures 3A, 3B and 3C, Figures 4A, 4B
and 4C, and Figures SA, SB and SC. The liner may extend only partially into the cavity as illustrated in Figures 3A, 3B, 4A and 4B. It may extend the full length of the cavity as illustrated in Figures 2A, 2B, SA and SB. In Figures SA and SB, the liner extends beyond the longitudinal internal walls of cavity 19, but does not block channel 17;
thus, cooling fluid can flow in all cases.
When the drive shaft is placed into contact with the liner 21, vibrations which occur when a hard metal drive shaft contacts a hard metal grinding cup are dramatically reduced. The liner may be comprised of artificial rubber, thermoplastic materials, or carbon based composite materials. These materials tend to provide significant durability while absorbing vibrations from the grinding tool. In this way, damage to the grinding cup and potential stripping of the profile of cavity 19 at the upper end of the grinding cup where the grinding cup contacts the drive shaft, or of the drive shaft itself, can be prevented.
Apart from preventing stripping of the grinding cup or the drive shaft, the vibration-damping liner provides quieter running and may contribute to fewer work-related injuries caused by vibration of the grinding tool.
Although an illustrative embodiment of the invention has been described, modifications of the structure will be apparent to those skilled in the art without departing from the spirit and scope of the invention.
Moreover, it would be an advantage to provide a grinding cup which is conformed so as to prevent the formation of bumps or nipples on the leading end of the drill bit buttons being ground.
The instant invention overcomes these problems in the prior art.
In a major aspect of the invention, a grinding cup for detachable connection to a drive shaft of a grinding machine for grinding buttons on drill bits comprises top and bottom surfaces, and a lower grinding section having a centrally disposed recess formed in the bottom surface of the grinding cup, and having the desired profile for the button to be ground, wherein the periphery of the lower grinding section comprises a series of reinforcing ribs extending longitudinally towards the bottom surface thereof, and wherein the peripheral edge of the bottom surface is bevelled to facilitate during grinding the removal of cutting fluid and steel from the face of the bit around the button, through the spaces between the ribs, said grinding cup further comprising an upper body section having a centrally disposed cavity formed in the top surface of the grinding cup, said cavity being shaped and sized to permit the drive shaft of the grinding machine to fit snugly within the cavity without retaining means.
In further aspects of the invention, the cavity further comprises a non-metal liner adapted to receive the drive shaft and to absorb vibrations generated between the drive shaft and the grinding cup during grinding operations.
In further aspects of the invention:
(a) The non-metal liner comprises artificial rubber, a thermoplastic material, or a carbon-based composite material;
(b) A single passageway connects the top and bottom surfaces of the grinding cup to permit a coolant to be provided to the surface of the button during grinding;
(c) The centrally disposed recess in the bottom surface of the grinding cup comprises multiple slots radiating from the centre of the surface, but not joining at said centre;
(d) The multiple slots comprise three slots each disposed at an angle of 60° to the adjacent slots;
(e) The grinding cup comprises a material capable of grinding tungsten-carbide button bits;
-$-(f) The grinding cup comprises a steel and diamond matrix.
Further aspects of the invention will become apparent from the following description of an illustrative embodiment of the invention.
$
Brief Description of the Drawings An illustrative embodiment of the invention is shown in the following drawings in which:
Figure 1 A is a perspective view of the grinding cup illustrating the cavity in the upper end of the cup;
Figure 1 B is a plan, elevation view of the grinding cup of the invention;
Figure 1 C is a perspective view of the grinding cup illustrating the recess in the lower 1$ end of the cup;
Figure 2A is a plan, cross-sectional, elevation view of a first embodiment of the grinding cup illustrating the vibration damping liner;
Figure 2B is a plan, cross-sectional, elevation view of a first embodiment of the vibration damping liner;
Figure 2C is a lower, end view of the grinding cup illustrating a first embodiment of the vibration damping liner;
Figure 3A is a plan, cross-sectional, elevation view of a second embodiment of the grinding cup illustrating the vibration damping liner;
Figure 3B is a plan, cross-sectional, elevation view of a second embodiment of the vibration damping liner;
Figure 3C is a lower, end view of the grinding cup illustrating a second embodiment of the vibration damping liner;
Figure 4A is a plan, cross-sectional, elevation view of a third embodiment of the grinding cup illustrating the vibration damping liner;
Figure 4B is a plan, cross-sectional, elevation view of a third embodiment of the vibration damping liner;
Figure 4C is a lower, end view of the grinding cup illustrating a third embodiment of the vibration damping liner;
Figure SA is a plan, cross-sectional, elevation view of a fourth embodiment of the grinding cup illustrating the vibration damping liner;
Figure SB is a plan, cross-sectional, elevation view of a fourth embodiment of the vibration damping liner;
Figure SC is a lower, end view of the grinding cup illustrating a fourth embodiment of the vibration damping liner;
Figure 6 is an upper, end view of the grinding cup illustrating the ribs and slots.
Detailed Description of the Invention Refernng to Figures 1 A, 1 B and 1 C, a grinding cup 1 having an upper end 3 and a lower end 5 comprises a hard material. Typically, the grinding cup, or at least the grinding portion thereof, comprises steel or a steel - diamond matrix.
Running longitudinally and located adjacent the lower end 5 of the grinding cup, are a series of ribs 7 lying around the perimeter of lower end S. The leading edge 9 of the lower end 5 is bevelled towards said perimeter and the upper end 3 of the grinding cup 1 to assist in removal of cutting fluid and cuttings from the drill bit button being reprofiled. The ribs 7 extend substantially to the leading edge of lower end 5. These _7_ ribs provide reinforcement to the leading edge of lower end 5 and prevent chipping of the grinding cup in this area. The spaces between the ribs 7 also provide areas where cutting fluid and cuttings may more easily pass. Moreover, the ribs widen the cutting area around each drill bit button, thus clearing away burrs which can develop at the base of such buttons using conventional grinding cups. This leads to cleaner button profiles.
Refernng to Figure 6, the leading lower end 5 of grinding cup 1 is illustrated in end view. Ribs 7 are spaced evenly around the perimeter of the crown 11 and extend at least to the leading end of bevelled surface 9. A series of slots 13 radiating from the centre of the grinding cup 1, but not joining at the centre, provide grinding and cutting action as the grinding cup rotates about the button being reproflled.
Cutting fluid flows through these slots to assist in keeping the work piece cool.
Since the slots do not join at the centre, and thus there is no opening at the centre of the grinding cup, no bump or nipple is formed at the centre of the button.
Refernng to Figure 2A, the grinding cup 1 typically comprises steel. The crown 11 maybe comprised of steel or a steel diamond matrix. A recessed opening in the lower end of the grinding cup provides a grinding surface 15 which is profiled to conform to the shape and size of the drill bit button being reprofiled. The recess may be concave, parabolic or conical (bullet-shaped) depending on the shape of the drill bit buttons to be reprofiled.
A channel 17 running along the longitudinal axis of the grinding cup conducts drilling fluid or coolant from a coolant source (not shown) to the button being reprofiled. Such coolant supplies are well-known in the art.
-$_ At the upper end 3 of the grinding cup is an opening or cavity 19 profiled slightly larger than the corresponding profile of the drive shaft 20 of the rotary tool to be inserted into the grinding cup in order to impart rotary motion to the grinding cup. Only that portion of the drive shaft which fits into the cavity is illustrated.
S
Figure 2B illustrates a non-metal liner 21 adapted to be snug-fit and, optionally, fixed with some adhesive or vulcanized, into cavity 19 located in the upper end of grinding cup 1. The exterior wall 23 of said liner contacts the surfaces of the grinding cup 1 adjacent the upper end 3 which define the cavity 19. The inner surface 25 of the liner is sized and profiled to fit snugly around the drive shaft 20 of the grinding tool. These features are also illustrated in Figure 2C, an end view of the upper end of the grinding cup.
Three alternative embodiments of the grinding cup with different non-metal liners are illustrated respectively in Figures 3A, 3B and 3C, Figures 4A, 4B
and 4C, and Figures SA, SB and SC. The liner may extend only partially into the cavity as illustrated in Figures 3A, 3B, 4A and 4B. It may extend the full length of the cavity as illustrated in Figures 2A, 2B, SA and SB. In Figures SA and SB, the liner extends beyond the longitudinal internal walls of cavity 19, but does not block channel 17;
thus, cooling fluid can flow in all cases.
When the drive shaft is placed into contact with the liner 21, vibrations which occur when a hard metal drive shaft contacts a hard metal grinding cup are dramatically reduced. The liner may be comprised of artificial rubber, thermoplastic materials, or carbon based composite materials. These materials tend to provide significant durability while absorbing vibrations from the grinding tool. In this way, damage to the grinding cup and potential stripping of the profile of cavity 19 at the upper end of the grinding cup where the grinding cup contacts the drive shaft, or of the drive shaft itself, can be prevented.
Apart from preventing stripping of the grinding cup or the drive shaft, the vibration-damping liner provides quieter running and may contribute to fewer work-related injuries caused by vibration of the grinding tool.
Although an illustrative embodiment of the invention has been described, modifications of the structure will be apparent to those skilled in the art without departing from the spirit and scope of the invention.
Claims (20)
1. A grinding cup for detachable connection to a drive shaft of a grinding machine for grinding buttons on drill bits comprises top and bottom surfaces, and a lower grinding section having a centrally disposed recess formed in the bottom surface of the grinding cup and having the desired profile for the button to be ground;
wherein the periphery of the lower grinding section comprises a series of reinforcing ribs extending longitudinally from the distal end thereof towards the top surface;
and wherein the peripheral edge of the bottom surface is bevelled to facilitate, during grinding, the removal of cutting fluid and steel from the face of the bit around the button through the spaces between the ribs; and comprising an upper body section having a centrally disposed cavity formed in the top surface of the grinding cup, said cavity being shaped and sized to permit the drive shaft of the grinding machine to fit snugly within the cavity without retaining means.
wherein the periphery of the lower grinding section comprises a series of reinforcing ribs extending longitudinally from the distal end thereof towards the top surface;
and wherein the peripheral edge of the bottom surface is bevelled to facilitate, during grinding, the removal of cutting fluid and steel from the face of the bit around the button through the spaces between the ribs; and comprising an upper body section having a centrally disposed cavity formed in the top surface of the grinding cup, said cavity being shaped and sized to permit the drive shaft of the grinding machine to fit snugly within the cavity without retaining means.
2. The grinding cup of claim 1, wherein said cavity further comprises a non-metal liner adapted to receive said drive shaft and to absorb vibrations generated between the drive shaft and the grinding cup during grinding operations.
3. The grinding cup of claim 2, wherein the non-metal liner comprises artificial rubber.
4. The grinding cup of claim 2, wherein the non-metal liner comprises a thermoplastic material.
5. The grinding cup of claim 2, wherein the non-metal liner comprises a carbon-based composite material.
6. The grinding cup of claim 1, wherein a single passageway connects the top and bottom surfaces of the grinding cup to permit a coolant to be provided to the surface of the button during grinding.
7. The grinding cup of claim 6, wherein the centrally disposed recess in the bottom surface of the grinding cup comprises multiple slots radiating from the centre of said surface, but not joining at said centre.
8. The grinding cup of claim 7, comprising three slots each disposed at an angle of 60° to the adjacent slots.
9. The grinding cup of claim 1, wherein the grinding cup comprises a material capable of grinding tungsten carbide button bits.
10. The grinding cup of claim 1, wherein the grinding cup comprises a steel and diamond matrix.
11. A grinding cup for detachable connection to a drive shaft of a grinding machine for grinding buttons on drill bits, said grinding cup having top and bottom surfaces, and comprising a lower grinding section having a centrally disposed recess formed in the bottom surface of said grinding cup and having the desired profile for the button to be ground; and further comprising an upper body section having a centrally disposed cavity formed in the top surface of the grinding cup, said cavity being shaped and sized to permit the drive shaft of the grinding machine to fit snugly within the cavity without any retaining means; said cavity further comprising a non-metal liner adapted to receive said drive shaft and to absorb vibrations generated between the drive shaft and the grinding cup during grinding operations.
12. The grinding cup of claim 11, wherein the non-metal liner comprises artificial rubber.
13. The grinding cup of claim 11, wherein the non-metal liner comprises thermoplastic material.
14. The grinding cup of claim 11, wherein the non-metal liner comprises a carbon-based composite material.
15. The grinding cup of claim 11, wherein a single passageway connects the top and bottom surfaces of the grinding cup to permit a coolant to be provided to the surface of the button during grinding.
16. The grinding cup of claim 11, wherein the centrally disposed recess in the bottom surface of the grinding cup comprises multiple slots radiating from the centre of said surface, but not joining at said centre.
17. The grinding cup of claim 16, comprising three slots each disposed at an angle of 60° to the adjacent slots.
18. The grinding cup of claim 11, wherein the grinding cup comprises a material capable of grinding tungsten carbide button bits.
19. The grinding cup of claim 11, wherein the grinding cup comprises a steel and diamond matrix.
20. The grinding cup of claim 11, wherein the periphery of the lower grinding section comprises a series of reinforcing ribs extending longitudinally to the bottom surface, and wherein the peripheral edge of the bottom surface is bevelled to facilitate, during grinding, the removal of cutting fluid and steel from the face of the bit around the button, through the spaces between the ribs adjacent the bottom surface.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2312100 CA2312100A1 (en) | 2000-06-22 | 2000-06-22 | Grinding cup for drill bits |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2312100 CA2312100A1 (en) | 2000-06-22 | 2000-06-22 | Grinding cup for drill bits |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2312100A1 true CA2312100A1 (en) | 2001-12-22 |
Family
ID=4166537
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2312100 Abandoned CA2312100A1 (en) | 2000-06-22 | 2000-06-22 | Grinding cup for drill bits |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2312100A1 (en) |
-
2000
- 2000-06-22 CA CA 2312100 patent/CA2312100A1/en not_active Abandoned
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA2576681C (en) | Rock drill bit | |
| CA2585564C (en) | Rock drill bit | |
| CN105014127B (en) | The method of rotary cutter especially drill bit and the such rotary cutter of manufacture | |
| KR100372609B1 (en) | Grinding Cup | |
| US3955635A (en) | Percussion drill bit | |
| JPH07329049A (en) | Rock drill | |
| JPH06297318A (en) | Cutter and cutting/boring device | |
| US4915182A (en) | Cutter elements for hollow drill bit | |
| JPH11291236A (en) | Drill tool | |
| US6835114B2 (en) | Grinding tool for buttons of a rock drill bit | |
| RU2179106C2 (en) | Grinding head and holder | |
| AU2001254560A1 (en) | Grinding tool for buttons of a rock drill bit | |
| MXPA97005952A (en) | Tripuration vessel and retene device | |
| CA2312100A1 (en) | Grinding cup for drill bits | |
| AU2004222834B2 (en) | Rotary hammerdrill bit | |
| JPH0634082Y2 (en) | Drill bit for drilling tool | |
| JP3799032B2 (en) | Drill | |
| JP3382748B2 (en) | Diamond drill bit for dry drilling | |
| JP2001232578A (en) | Drilling and/or chiseling tool | |
| CN209754102U (en) | U drill that can fix a position | |
| KR102652633B1 (en) | Cutting tool for face cutting apparatus | |
| US20240025080A1 (en) | Tool for a mobile machine tool | |
| AU711663B2 (en) | Grinding cup and holder device | |
| CA2404156C (en) | Grinding tool for buttons of a rock drill bit | |
| JP2967031B2 (en) | Diamond core bits for dry drilling |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| FZDE | Dead |