US20090057030A1

US20090057030A1 - Mining claw bit

Info

Publication number: US20090057030A1
Application number: US12/193,463
Authority: US
Inventors: Roger Didericksen; S. Ravi Teja; Irrinki Rangayya Naidu
Original assignee: Sandvik Mining and Construction Oy
Current assignee: Sandvik Intellectual Property AB
Priority date: 2007-09-05
Filing date: 2008-08-18
Publication date: 2009-03-05
Also published as: ZA200807648B; CA2639311A1; AU2008207696B2; AU2008207696A1

Abstract

A mining bit includes a bit body having a central axis, the bit body having a forward portion with faceted surfaces and a rearward attachment portion. The mining bit further includes a plurality of wings extending from the faceted surfaces of the bit body and arranged about a central hub. A plurality of cutting elements are disposed on distal ends of the wings.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This Application claims the priority of a provisional application under 35 U.S.C. §119(e), namely U.S. Patent Application Ser. No. 60/970,146 filed on Sep. 5, 2007, which is incorporated by reference in its entirety herein.

BACKGROUND

1. Field of the Disclosure
Embodiments disclosed herein relate generally to equipment used in the mining industry. More particularly, embodiments disclosed herein relate to mining claw bits.
2. Background Art
Relatively large rotary drills may commonly be used in the mining industry for the drilling of holes in ore beds and strata. Large earth boring machines capable of drilling to depths of 500 feet or more may be used in a process which involves mapping out a drill pattern, drilling a blast hole, and filling the blast hole with explosives. Blasts may consist of 200 to 300 holes, each hole containing up to one ton of explosives. Various types of drill bits have been developed and used in the process, including drag bits, claw bits, and conical roller-cone bits. Drill bits may use steel conical cutting element or teeth with extremely hard tungsten carbide tips secured into sockets in the forward or working ends of the cutters.
For the drill bit to drill through a formation, sufficient rotational moment and axial force must be applied to the bit to cause the cutting elements to cut into and/or crush formation as the bit is rotated. Axial force applied to the bit is typically referred to as the weight on bit (“WOB”). Additionally, the portion of the weight of drilling tool assembly supported by a suspending mechanism of rig is typically referred to as the hook load. Additionally, rotational moment can be provided by BHA components such as positive displacement motor or down hole turbines. Rotational moment applied to the drilling tool assembly by the drill rig (usually by a rotary table or a top drive) to turn the drilling tool assembly is referred to as the rotary torque. The speed at which the drilling rig rotates drilling tool assembly, typically measured in revolutions per minute (“RPM”), is referred to as the rotary speed.
The speed and economy with which a wellbore is drilled, as well as the quality of the hole drilled, depend on a number of factors. These factors include, among others, the mechanical properties of the rocks which are drilled, the diameter and type of the drill bit used, the flow rate of the drilling fluid, and the rotary speed and axial force applied to the drill bit. It is generally the case that for any particular mechanical property of a formation, a drill bit's rate of penetration (“ROP”) corresponds to the amount of axial force on and the rotary speed of the drill bit. The rate at which the drill bit wears out is generally related to the ROP. Various methods have been developed to optimize various drilling parameters to achieve various desirable results.
U.S. Pat. No. 5,735,360, assigned to Engstrom, discloses a rotary mining bit suitable for use in the drilling of blasting holes in the mining industry. The bit comprises a central hollow body with a plurality of wings extending outwardly therefrom, with each wing having a leading edge with a plurality of cutting tooth sockets disposed therealong and each of the sockets having a cutting tooth affixed therein.
During drilling operations, various formations may be encountered which require more robust bits because of harder material. Further, due to the harder formations, the rate of penetration, or ROP, of the drill bit may decrease. Also contributing to decreased ROP may be an inability to remove cuttings from a borehole as needed. Lack of cutting removal may be due to insufficient cleaning from flow nozzles because of improper nozzle size or placement on the drill bit.
Accordingly, there exists a need for a mining bit having increased structural rigidity while still allowing for easy manufacturability. Further, a person skilled in the art may appreciate a mining bit providing an improved rate of penetration (ROP) during drilling operations and more efficient cutting removal.

SUMMARY OF THE DISCLOSURE

In one aspect, embodiments disclosed herein relate to a mining bit comprising a bit body having a central axis, the bit body comprising a forward portion having faceted surfaces and a rearward attachment portion. The mining bit further includes a plurality of wings extending from the faceted surfaces of the bit body and arranged about a central hub and a plurality of cutting elements disposed on distal ends of the wings.
In another aspect, embodiments disclosed herein relate to a mining bit comprising a bit body having a central axis, the bit body comprising a forward portion having faceted surfaces and a rearward attachment portion. The mining bit further includes a plurality of curved wings extending from the faceted surfaces of the bit body and arranged about a central hub forward the forward portion of the bit body and a plurality of cutting elements disposed on distal ends of the wings.
In another aspect, embodiments disclosed herein relate to a mining bit comprising a bit body having a central axis, the bit body comprising a forward portion having faceted surfaces and a rearward attachment portion. The mining bit further includes a plurality of slanted wings extending from the faceted surfaces of the bit body and arranged about a central hub forward the forward portion of the bit body and a plurality of cutting elements disposed on distal ends of the wings.
In another aspect, embodiments disclosed herein relate to a mining bit comprising a bit body having a central axis, the bit body comprising a forward portion having faceted surfaces and a rearward attachment portion The mining bit further includes a plurality of offset wings extending from the faceted surfaces of the bit body and arranged about a central hub forward the forward portion of the bit body and a plurality of cutting elements disposed on distal ends of the wings.
In another aspect, embodiments disclosed herein relate to a mining bit comprising a bit body having a central axis, the bit body comprising a conical forward portion and a rearward attachment portion. The mining bit further includes a plurality of wings extending from the conical portion of the bit body and arranged about a central hub and a plurality of cutting element receptacles configured to removeably receive cutting elements disposed therein.
In another aspect, embodiments disclosed herein relate to a method of assembling a mining bit, the method comprising providing a bit body having a central axis and comprising faceted surfaces on a forward section, attaching a plurality of wings to the faceted surfaces of the bit body and to a central hub, positioning the central hub forward of the forward section of the bit body, and disposing cutting elements onto distal ends of the wings.
Other aspects and advantages of the invention will be apparent from the following description and the appended claims.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1A is a side view of a mining bit with flat blades in accordance with embodiments of the present disclosure.

FIG. 1B is an end view of the mining bit with flat blades in accordance with embodiments of the present disclosure.

FIG. 1C is an end view of a central hub of the mining bit in accordance with embodiments of the present disclosure.

FIG. 1D is a side view of a mining bit having a non-faceted forward section in accordance with embodiments of the present disclosure.

FIG. 1E is an end view of a mining bit having a non-faceted forward section in accordance with embodiments of the present disclosure.

FIG. 1F is a side view of a mining bit having slots in wings in accordance with embodiments of the present disclosure.

FIG. 1G is a side view of a mining bit having slots in wings in accordance with embodiments of the present disclosure.

FIG. 2A is a side view of a mining bit with offset flat blades in accordance with embodiments of the present disclosure.

FIG. 2B is an end view of the mining bit with offset flat blades in accordance with embodiments of the present disclosure.

FIG. 3A is a side view of a mining bit with offset, slanted flat blades in accordance with embodiments of the present disclosure.

FIG. 3B is an end view of the mining bit with offset, slanted flat blades in accordance with embodiments of the present disclosure.

FIG. 4A is a side view of a mining bit with curved offset blades in accordance with embodiments of the present disclosure.

FIG. 4B is an end view of the mining bit with curved offset blades in accordance with embodiments of the present disclosure.

FIG. 5A is a side view of a mining bit with variable spaced wings in accordance with embodiments of the present disclosure.

FIG. 5B is an end view of the mining bit with variable spaced wings in accordance with embodiments of the present disclosure.

FIG. 6A is an end view of a mining bit with five wings in accordance with embodiments of the present disclosure.

FIG. 6B is an end view of a mining bit with three wings in accordance with embodiments of the present disclosure.

FIG. 7A is a side view of a mining bit including radial nozzles in accordance with embodiments of the present disclosure.

FIG. 7B is an end view of a mining bit including radial nozzles in accordance with embodiments of the present disclosure.

FIG. 7C is a section view of a mining bit including radial nozzles in accordance with embodiments of the present disclosure.

FIG. 8A is a side view of a mining bit including radial and center nozzle in accordance with embodiments of the present disclosure.

FIG. 8B is an end view of a mining bit including radial and center nozzle in accordance with embodiments of the present disclosure.

FIG. 8C is a section view of a mining bit including radial and center nozzle in accordance with embodiments of the present disclosure.

DETAILED DESCRIPTION

In one aspect, embodiments disclosed herein relate to equipment used in the mining industry. More particularly, embodiments disclosed herein relate to mining claw bits.
The present disclosure comprises various embodiments of a rotary mining bit, which may be used for the drilling of blast holes in mineral deposits for the placement of explosive therein. The bit may be adapted for use in relatively soft formations as well as in harder mineral deposits. While the present bit is particularly adapted for the drilling in the mining industry, it may also be adaptable for the drilling of holes for gas, oil, and water wells, as well as for the drilling of other holes for various other purposes.
FIG. 1A shows a mining bit 100 in accordance with embodiments of the present disclosure. Mining bit 100 includes a bit body 102 having a central axis 103, and further includes a non-conical, polygonal, or faceted forward section 104 and a rearward attachment section 106 for connection with a drill stem (not shown). A person skilled in the art will understand various methods to secure attachment section 106 of mining bit 100 to the drill stem (not shown) including threading and welding. Referring to FIG. 1D and 1E, in certain embodiments, mining bit 100 may comprise a bit body 102 having a conical, or non-faceted, forward section 104.
Further, mining bit 100 comprises wings 108 extending from bit body 102. Leading edges 116 of wings 108 may be defined as the distal edge of wings 108 or the face of wing 108 which is facing in a downhole direction of mining bit 100. Leading edges 116 of wings 108 may be angled with respect to a plane normal to central axis 103. The angle may vary depending on rate of penetration (ROP), cutting removal efficiency, etc. desired, of which would be known to one skilled in the art. Further, leading edge 116 of wings 108 may be parallel with respect to a plane normal to central axis 103.
Still further, receptacle mounts 109 may be disposed on leading edges 116 of wings 108 and configured to releasably receive cutting element receptacles 110, and cutting elements, or picks, 112 disposed in cutting element receptacles 110. Cutting element receptacles 110 may be attached to leading edge 116 of wings 108 by methods including welding, brazing, fasteners, or the like known to those skilled in the art. Cutting elements 112 may include mining picks, polycrystalline diamond compact cutters, tungsten carbide inserts or other cutters known to those skilled in the art. Embodiments disclosed herein may use picks for drilling operations in the mining industry.
Referring to FIG. 1F, in certain embodiments, receptacle mounts may be omitted and slots 118 may be machined or drilled directly into wings 108. Cutting elements (not shown) may then be inserted into slots 118 and retained by methods known to those skilled in the art including, threading, welding, or press fitting. Still further, referring to FIG. 1G, in certain embodiments cutting element receptacles 110 containing picks 112 may be disposed in slots milled directly into wings 108. Still further, in certain embodiments, cutting element receptacles 110 may be formed as an integral part of wings 108.
Referring back to FIG. 1A, mining bit 100 may include a central hub 114 at which wings 108 adjoin. Central hub 114 may have a cylindrical or conical outer profile, or may have a non-conical or faceted outer profile for which to attach wings 108. A person having ordinary skill in the art will understand methods in which to attach the wings to bit body 102 and central hub 114 including, but not limited to, welding, brazing, and fasteners. Referring to FIG. 1C, an end view of a working or forward end 104 of mining bit 100 is shown at which mining bit 100 may comprise a central hub 114 having a solid body with no center hole therethrough. In alternate embodiments, mining bit 100 may comprise a central hub 114 having a center hole, or through hole, in which a center nozzle or center pick may be installed.
In certain embodiments, central hub 114 may be centered about central axis 103 of bit body 102 so that mining bit 100 may be configured to drill substantially straight. In still further embodiments, central hub 114 may be offset from central axis 103 of bit body 102 thereby providing a possibility of angled or directional drilling with mining bit 100. Further, central hub 114 may be forward of forward section 104 of bit body 102 when mining bit 100 is assembled, and, therefore, may not be in contact with bit body 102.
Now, referring to FIG. 1B, an end view of the rearward or attachment end 106 of mining bit 100 is shown in accordance with embodiments disclosed herein. As shown, wings 108 may be spaced evenly 90 degrees apart from each other about a circumference of bit body 102. Further, two wings 108 may be parallel and centered with a vertical plane 109 and the remaining two wings 108 parallel and centered with a horizontal plane 111. Mining bit 100 further includes air passages 114 which run through bit body 102 to flush debris from the hole as material is broken up at the working end of the hole being drilled by mining bit 100. It should be understood that air passages 114 may vary in the number run through bit body 102, the diameter of air passages 114, and the direction in which they are run. Further, air passages 114 may be configured in various cross-sectional area shapes, including, but not limited to, circular, square, triangular or other shapes known to a person skilled in the art.
Referring back to FIG. 1A, picks 112 disposed in cutting element receptacles 110 on wings 108 may vary in size and shape as will be understood by a person skilled in the art. Picks 112 may be of a hardened material suitable for downhole holing drilling operations including, but not limited to, polycrystalline diamond compact cutters or steel cutters with tungsten carbide tips. Further, it will be understood by a person skilled in the art that varying numbers of picks 112 may be used with mining bit 100. Still further, picks 112 may be spaced in various configurations along leading edge 116 of wings 108, for example, evenly or unevenly spaced.
Further, as shown in FIG. 1A, mining bit 100 includes flat wings 108 with coplanar surfaces, or rectangular cross-sections, and that are also centered with the central axis 103 of bit body 102. In alternate embodiments, wings 108 may comprise flat non-coplanar surfaces resulting in a trapezoidal cross-sectional area with a larger base and flat surfaces tapering to a thinner outer cross-sectional area extending radially outwards. Further, various configurations of attaching wings 108 to bit body 102 may be used on mining bit 100 as described in the following embodiments.
Referring to FIG. 2A, a side view of a mining bit 200 is shown in accordance with certain embodiments of the present disclosure. Mining bit 200 comprises flat wings 208 disposed on a bit body 202 that may be offset a distance 205 from a central axis 203. In selected embodiments, offset distance 205 may be varied between about 0.050 inches to about 1.5 inches, as will be known to a person having ordinary skill in the art. FIG. 2B is an end view of a forward or working end of mining bit 200 which shows wings 208 spaced 90 degrees apart with two wings 208 parallel and offset with a vertical plane 209 and the remaining two wings parallel and offset with a horizontal plane 211. Further, in certain embodiments, wings 208 may be offset a distance 205 as mentioned above and slanted (not shown) at a radial angle with respect to vertical plane 209 and horizontal plane 211 rather than parallel. Further, a person having ordinary skill in the art will appreciate that the radial angle (not shown) of wings 208 may be varied.
Now referring to FIG. 3A and FIG. 3B, a mining bit 300 is shown in accordance with certain embodiments of the present disclosure. Mining bit 300 comprises flat wings 308 offset a distance (not shown) from central axis 303 and slanted at a longitudinal angle 307 from central axis 303 and slanted at a radial angle 315 (FIG. 3B) from vertical plane 309 and horizontal plane 311. In selected embodiments, the longitudinal angle 307 may be varied from about 1 degree to about 40 degrees, and radial angle 315 of wings 308 may be varied from about 1 degree to about 30 degrees, as will be known to a person having ordinary skill in the art. Further, in selected embodiments, the offset distance (not shown) may vary from about 0.050 inches to about 4 inches. Certain embodiments may form a mining bit 300 having straight wings offset a distance from central axis 303 and slanted at a longitudinal angle 307 from central axis 303, but no radial slant angle. Further, in alternate embodiments of the present disclosure, a mining bit 300 may be formed having straight wings 308 offset a distance 305 from central axis 303 and slanted at a radial angle 315 from vertical plane 309 and horizontal plane 311, but no longitudinal slant angle. Still further, certain embodiments may form a mining bit 300 having straight wings slanted at a longitudinal angle 307 from central axis 303 and slanted at a radial angle 315 from vertical plane 309 and horizontal plane 311, but no offset. A person of ordinary skill in the art will appreciate the various combinations and/or permutations that may be used in configuring the wings on the bit body.
Referring now to FIG. 4A, a mining bit 400 is shown in accordance with still further embodiments of the present disclosure. Mining bit 400 comprises curved wings 408 disposed on a bit body 402 that may be offset a distance 405 from a central axis 403. As mentioned previously, distance from central axis 403 may be varied as will be known to a person skilled in the art. FIG. 4B is an end view of a working or forward end of mining bit 400 showing curved wings 408 in relation to a vertical plane 409 and a horizontal plane 411. In certain embodiments (not shown), curved wings 408 may be offset a distance from central axis 403 and slanted at a radial angle from a vertical plane 409 and a horizontal plane 411.
Now referring to FIG. 5A, a side view of a mining bit 500 is shown in accordance with embodiments of the present disclosure. Mining bit 500 comprises wings 508 disposed on bit body 502 that may be unevenly or variably spaced about a central axis 503 of bit body 502. Referring to FIG. 5B an end view of a working or forward end of mining bit 500 with variable spacing between wings 508 is shown in accordance with embodiments of the present disclosure. As shown, angles 520, 522, and 524 may all differ from each other to provide the variable spacing. In one example, angle 520 may be 100 degrees, angle 522 may be 75 degrees, and angle 524 may be 105 degrees, of which will be understood by a person skilled in the art.
Embodiments disclosed herein may not be limited to a mining bit having four wings disposed on the bit body. Referring to FIG. 6A and 6B, a mining bit 600 having varying numbers of wings are shown in accordance with embodiments disclosed herein. Shown in FIG. 6A is an end view of a working or forward end of mining bit 600 shown with five wings 608 disposed on a bit body 602. Now referring to FIG. 6B, an end view of mining bit 600 with three wings 608 disposed on bit body 602 is shown. Further, in certain embodiments (not shown), mining bit may comprise two wings oriented 180 degrees apart from each other. A person having ordinary skill in the art will understand the various options concerning the number of wings used on the mining bit. Desired rate of penetration, overall bit weight, and the hole size to be drilled may be a few of the determining factors in deciding the number of wings to use. Further, combinations and/or permutations previously discussed involved with attachment and configurations of wings may be used with mining bits regardless of the number of wings attached to the bit body.
Referring to FIG. 7A, a side view of a mining bit 700 configured for radial nozzles is shown in accordance with embodiments disclosed herein. Mining bit 700 comprises a plurality of radial nozzle receptacles 720 disposed in nozzle bosses 722 arranged about a central axis 703 of mining bit 700. Nozzle bosses 722 may be formed as an integral part of a bit body 702, or may be attached to bit body 702. Further, nozzle bosses 722 may have carbide protection inserts 724 mounted on an outer gage pad surface 726. As shown, nozzle bosses 722 may be arranged in an alternating configuration with wings 708 mounted on bit body 702. FIG. 7B is an end view of mining bit 700 in accordance with embodiments disclosed herein showing the alternating configuration of radial nozzle receptacles 720 and wings 708 about central axis 703 of mining bit 700.
Referring now to FIG. 7C, a section side view of mining bit 700 configured for radial nozzles is shown in accordance with embodiments disclosed herein. As shown, a center air passage 730 extends through bit body 702 to connect with multiple radial air passages 732. Radial air passages 732 may extend from center air passage 730 to intersect nozzle boss air passages 723. Air passages in mining bit 700 may have a circular cross-sectional area or other geometry known to those skilled in the art. Further, air passages may have inner diameter surfaces which provide flow characteristics which will be understood by persons skilled in the art. Further, nozzles (not shown) may be inserted into radial nozzle receptacles 720 by methods known to those skilled in the art, including, but not limited to, threading, groove and pin retainer, and press fit. Nozzles may be adjustable and angled to direct flow to desired locations of mining bit 700. Still further, nozzles, which are well known in the art, may vary in size or shape to adjust the fluid or airflow through them. In certain embodiments, fluid or airflow may be directed through radial nozzle receptacles 720 without nozzles inserted in them.
Referring now to FIG. 8A, a side view of a mining bit 800 configured for radial nozzles and a center nozzle is shown in accordance with embodiments of the present disclosure. Mining bit 800 comprises a plurality of radial nozzle receptacles 820 arranged about a central axis 803 of mining bit 800, and further comprises a center nozzle receptacle 840. Center nozzle receptacle 840 may be configured to be centered about central axis 803, or alternatively, may be off-centered from central axis 803. Center nozzle receptacle 840 may be formed integrally with a bit body 802 of mining bit 800, or may be attached using methods known to those skilled in the art. Radial nozzle receptacles 820 may be configured as described previously and shown in FIG. 7A-7C. Referring to FIG. 8B, an end view of mining bit 800 is shown in accordance with embodiments of the present disclosure. Mining bit 800 is shown with radial nozzle receptacles 820 and center nozzle receptacle 840 arranged about central axis 803 of mining bit 800.
Now referring to FIG. 8C, a section side view of mining bit 800 configured for radial nozzle receptacles 820 and central nozzle receptacle 840 is shown in accordance with embodiments of the present disclosure. A center air passage 830 may extend through bit body 802 to connect with multiple radial air passages 832. Radial air passages 832 may extend from center air passage 830 to intersect nozzle boss air passages 823. Center air passage 830 may comprise a divergent section 842 which terminates at center nozzle receptacle 840. As previously mentioned, nozzles (not shown) may be inserted into radial nozzle receptacles 820 and center nozzle receptacle 840 by methods known to those skilled in the art, including, but not limited to, threading, groove and pin retainer, and press fit. Nozzles may be adjustable and angled to direct flow to desired locations of the mining bit 800. Still further, nozzles may vary in size or shape to adjust the fluid or airflow through them. In certain embodiments, fluid or airflow may be directed through radial nozzle receptacles 820 and center nozzle receptacle 840 without nozzles inserted in them.
Advantageously, embodiments of the present disclosure may provide for a mining bit that is substantially easier to manufacture, and in particular, easier to attach the wings to the bit body. The faceted forward section of the bit body may provide easier placement of the wings on the bit body by providing faceted surfaces on which to attach the wings. For example, it may require less time to fit and weld the wings to the faceted surfaces as opposed to fitting the wings to conform to a conical or otherwise rounded surface and then attach the wings. Reducing manufacturing time and labor costs will be appreciated by those skilled in the art. The faceted bit body may also provide for easier placement of nozzles used to remove cuttings from the cutters.
Further, embodiments of the present disclosure may advantageously provide for a mining bit having multiple air passages through the center of the bit body. In selected embodiments, the air passages may provide a more directed air flow which may clean a bottom of a hole being drilled better by removing more cutting material and thereby increasing the efficiency of cutting removal. The air passages may cause a cross flow pattern to occur which may further increase the efficiency of cuttings removal from the hole. Also, multiple air passages may provide the ability to adjust air flow parameters as a whole through the bit body or individually per each wing. Multiple, adjustable, replaceable air passages and nozzles may be provided in certain embodiments which may allow for faster replacement. Further, nozzle sizes may be adjusted without removing the mining bit from a drill string. Adjustable features of the nozzles may include positioning in the wings so as to vary a flow direction from the nozzles, lengths of the nozzles, diameter of the nozzles, or other parameters known to a person skilled in the art.
Still further, embodiments of the present disclosure may advantageously provide for a mining bit with added structural strength. In certain embodiments, the wings may comprise non-coplanar surfaces, or have a trapezoidal cross-sectional area with a thicker base which tapers radially outward to a thinner cross-sectional area. Wings having the non-coplanar surfaces may add rigidity at the base of the wings where they are attached to the bit body, thereby increasing the overall strength against shearing and other forces experienced during operations downhole. Further, non-coplanar wings may provide improved removal of cuttings from the hole, acting similar to curved wings. Certain embodiments having curved wings, or “spiral” wings, may also provide better removal of cuttings from the hole by allowing for an easier path for the cuttings to exit. Further, curved wings may provide structural rigidity for various loading experienced downhole, for example, torque loading. Still further, flat wings slanted at a longitudinal angle from the center axis of the bit body may provide many advantages of curved wings along with reduced cost of manufacturing. The flat, slanted wings may further provide torque offsetting and spiral effect.
Advantageously, embodiments of the present disclosure may further provide for a mining bit with the ability to dampen vibrations which may occur during drilling operations. A mining bit with a variable spacing of the wings, as previously described, may change the natural frequency of the drilling string and mining bit and result in and adjustment and/or reduction of vibrations experienced downhole. A reduction of vibrations downhole may provide an increased rate of penetration (ROP) for the mining bit which may lead to reduced drilling time and drilling costs.
Additionally, wings offset a distance from the central axis of the bit body may provide an increased rate of penetration (ROP) of the mining bit. Offset wings may provide a better cutting action as well as an improved efficiency and speed of a removal of the cuttings from the hole bottom. Offset wings may further allow cutters to be positioned closer to the center of the bit, thereby providing the ability to leave more room if desired between cutters spaced along a leading edge of the wings.
Advantageously, embodiments of the present disclosure may provide for a mining bit in which picks may be variably positioned on the leading edges of the wings. For example, moving the picks radially inward on the wings toward the central axis of the bit body may provide improved bit balancing or bit loading. A person having ordinary skill in the art will appreciate the ability to manipulate downhole bit conditions which may reduce vibrations and improve ROP as previously mentioned. Bit balancing may further be improved by varying a diameter of the picks. For example, the diameter of the picks positioned closer to the center of the bit body may be reduced to allow for more to be attached on the blade, or to have less cutting occur near the center of the bit, or to provide for more weight to be concentrated on outer picks of the mining bit.
Further, certain embodiments of the present disclosure may advantageously provide for a mining bit with wings having added rigidity. Referring back to FIG. 1C, wings 108 may be attached to an outer circumference of central hub 114 so that wings 108 may not be in contact with one another. This configuration may provide for increased rigidity of the wings as they may be solidly held together by central hub 114. Further, wings 108 attached to central hub 114 may allow for easier manufacturing of mining bit 100 because of less complicated fitting requirements and weld joints. It will be understood by a person having ordinary skill in the art that wings may be attached to central hub by methods other than welding, including brazing, fasteners, etc.
Still further, certain embodiments of the present disclosure may provide for a mining bit with a solid central hub not having a center hole drilled thru. The solid central hub may provide increased rigidity of the attached wings. In alternate embodiments of the present disclosure, the mining bit may comprise a hollow central hub having a center hole drilled thru. The center hole of the hollow hub may allow for a center nozzle to be installed in the center of the wings. The center nozzle may improve the efficiency of cutting removal from the borehole by removing cuttings from a center portion of the mining bit.
While the present disclosure has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments may be devised which do not depart from the scope of the disclosure as described herein. Accordingly, the scope of the disclosure should be limited only by the attached claims.

Claims

1. A mining bit, comprising:

a bit body having a central axis, the bit body comprising a forward portion having faceted surfaces and a rearward attachment portion;

a plurality of wings extending from the faceted surfaces of the bit body and arranged about a central hub;

a plurality of cutting elements disposed on distal ends of the wings.

2. The mining bit of claim 1, further comprising cutting element receptacles to removeably receive the cutting elements.

3. The bit of claim 1, wherein the rearward attachment portion of the bit body is configured to attach to a drill stem.

4. The bit of claim 1, wherein the wings comprise non-coplanar surfaces.

5. The bit of claim 4, wherein the wings comprise a trapezoidal cross-sectional area with a larger base and flat surfaces tapering to a thinner outer cross-sectional area extending radially outwards.

6. The bit of claim 1, wherein the wings comprise coplanar surfaces.

7. The bit of claim 1, wherein the wings are positioned parallel and centered with the central axis of the bit body.

8. The bit of claim 1, wherein the wings are positioned offset and parallel with the central axis of the bit body.

9. The bit of claim 1, wherein the wings are positioned offset and slanted at a longitudinal angle from the central axis of the bit body.

10. The bit of claim 1, wherein the wings are positioned slanted at a longitudinal angle from the central axis of the bit body.

11. The bit of claim 1, wherein the wings are positioned slanted at a radial angle from the central axis of the bit body.

12. The bit of claim 1, wherein the wings are positioned slanted at a longitudinal and radial angle from the central axis of the bit body.

13. The bit of claim 1, wherein the wings are curved.

14. The bit of claim 1, wherein the wings are curved and offset from the central axis of the bit body.

15. The bit of claim 1, wherein the wings are variably spaced around the central axis of the bit body.

16. The bit of claim 1, wherein the central hub is solid.

17. The bit of claim 1, wherein the central hub comprises a through hole.

18. The bit of claim 1, further comprising air passages through the bit body.

19. The bit of claim 1, further comprising removable radial and center nozzles.

20. The bit of claim 19, wherein the air passages are in communication with removable radial and center nozzles.

21. The bit of claim 20, wherein the radial nozzle and center nozzles are adjustable.

22. The bit of claim 1, wherein the cutting elements are spaced evenly along a distal end of the wings.

23. The bit of claim 1, wherein the cutting elements vary in diameter.

24. The bit of claim 1, wherein the central hub is centered about the central axis of the bit body.

25. The bit of claim 1, wherein the central hub is offset from the central axis of the bit body.

26. The bit of claim 1, wherein the central hub comprises a cylindrical outer surface.

27. The bit of claim 1, wherein the central hub comprises a faceted outer surface.

28. The bit of claim 1, further comprising slots milled in the wings to receive cutting element receptacles and cutting elements.

29. The bit of claim 1, further comprising cutting element receptacles formed and drilled in the wings to receive cutting elements.

30. The bit of claim 1, wherein the cutting element receptacles are attached directly to the wings without milling.

31. The bit of claim 1, wherein the central hub is positioned forward the forward portion of the bit body.

32. A method of assembling a mining bit, the method comprising:

providing a bit body having a central axis and comprising faceted surfaces on a forward section;

attaching a plurality of wings to the faceted surfaces of the bit body and to a central hub, positioning the central hub forward of the forward section of the bit body;

disposing cutting elements on distal ends of the wings.

33. The method of claim 32, wherein cutting elements are removeably disposed in cutting element receptacles attached to the wings.

34. The method of claim 32, wherein the wings are attached offset from the central axis of the bit body.

35. The method of claim 32, wherein the wings are attached slanted at a longitudinal angle from the central axis of the bit body.

36. The method of claim 32, wherein the wings are curved.

37. A mining bit, comprising:

a bit body having a central axis, the bit body comprising a conical forward portion and a rearward attachment portion;

a plurality of wings extending from the conical portion of the bit body and arranged about a central hub;

a plurality of cutting elements disposed on distal ends of the wings.

38. The mining bit of claim 37, further comprising cutting element receptacles to removeably receive the cutting elements.

39. The bit of claim 37, wherein the rearward attachment portion of the bit body is configured to attach to a drill stem.

40. The bit of claim 37, wherein the wings comprise non-coplanar surfaces.

41. The bit of claim 40, wherein the wings comprise a trapezoidal cross-sectional area with a larger base and flat surfaces tapering to a thinner outer cross-sectional area extending radially outwards

42. The bit of claim 37, wherein the wings comprise coplanar surfaces.

43. The bit of claim 37, wherein the wings are positioned parallel and centered with the central axis of the bit body.

44. The bit of claim 37, wherein the wings are positioned offset and parallel with the central axis of the bit body.

45. The bit of claim 37, wherein the wings are positioned offset and slanted at a longitudinal angle from the central axis of the bit body.

46. The bit of claim 37, wherein the wings are positioned slanted at a longitudinal angle from the central axis of the bit body.

47. The bit of claim 37, wherein the wings are positioned slanted at a radial angle from the central axis of the bit body.

48. The bit of claim 37, wherein the wings are positioned slanted at a longitudinal and radial angle from the central axis of the bit body.

49. The bit of claim 37, wherein the wings are curved.

50. The bit of claim 37, wherein the wings are curved and offset from the central axis of the bit body.

51. The bit of claim 37, wherein the wings are variably spaced around the central axis of the bit body.

52. The bit of claim 37, wherein the central hub is solid.

53. The bit of claim 37, wherein the central hub comprises a through hole.

54. The bit of claim 37, further comprising air passages through the bit body.

55. The bit of claim 37, further comprising removable radial and center nozzles.

56. The bit of claim 55, wherein the air passages are in communication with removable radial and center nozzles.

57. The bit of claim 56, wherein the radial nozzle and center nozzles are adjustable.

58. The bit of claim 37, wherein the cutting elements are spaced evenly along a distal end of the wings.

59. The bit of claim 37, wherein the cutting elements vary in diameter.

60. The bit of claim 37, wherein the central hub is centered about the central axis of the bit body.

61. The bit of claim 37, wherein the central hub is offset from the central axis of the bit body.

62. The bit of claim 37, wherein the central hub comprises a cylindrical outer surface.

63. The bit of claim 37, wherein the central hub comprises a faceted outer surface.

64. The bit of claim 37, further comprising slots milled in the wings to receive cutting element receptacles and cutting elements.

65. The bit of claim 37, further comprising cutting element receptacles formed and drilled in the wings to receive cutting elements.

66. The bit of claim 37, wherein the cutting element receptacles are attached directly to the wings without milling.

67. The bit of claim 37, wherein the central hub is positioned forward the forward portion of the bit body.