Abstract
A polycrystalline diamond drill bit for percussion drilling, in small hole high silica ground. The bit is made having a bit body, and a series of inserts locating in the bit body, and the bits are made using a double chisel design, or a modified double chisel design. The inserts are either chiseled shaped inserts, or the inserts are a combination of chisel shaped inserts and conical inserts, and are set into the bit body at very specific angles, in order to attain slicing of the earth when percussion drilling is performed. The inserts have specific lengths to cut clearance for the bit body. The cutting angle and the radius of the tip of each insert in addition to the diameter of the inserts, provide for use of a machine thrust pressure and machine torque pressure at low ranges when the PCD bits are used in percussion drilling.
Claims
1. A percussion drill bit, said drill bit formed having a body, the body capable of being secured with a drill shaft in preparation for a percussion drilling operation, the body having a center axis and a cutting face, the cutting face having a frontal face, and a beveled face extending outwardly radially therefrom, the body and the cutting face being integrally formed; said drill bit formed of a double chisel design or modified double chisel design configuration; said drill bit capable of operating at a machine torque pressure of less than 20 Bar, and a machine thrust pressure of less than 20 Bar; said frontal face and said beveled face having a series of openings provided therein, and inserts being pressed fitted within said openings in preparation for usage of the drill bit in said percussion drilling operation, each of said inserts having a tip comprising a polycrystalline diamond coating; select of said inserts being of a conical design, and others of said inserts being of a chisel design; the chisel design inserts being arranged at an angle between about 0 to about 45 within the drill bit to provide for a plowing or slicing action of the drill bits when cutting of the earth during a percussion drilling operation; said drill bit body having a gauged diameter of between about 1 inches to 8 inches in diameter; and each insert having a gripping portion of a diameter between about 0.300 to 0.520, each insert having a grip length of between about 0.300 and 0.600, and each tip of each insert having a length of between about 0.200 to 0.360 in their location within the percussion drill bit in preparation for a drilling operation.
2. The percussion drill bit of claim 1 wherein said chisel inserts are arranged at approximately 15 off the perpendicular to the arc of rotation of the drill bit during its usage in percussion drilling.
3. The percussion drill bit of claim 1 wherein said inserts are arranged at approximately 30 off of the perpendicular to the arc of rotation of the drill bit during the performance of a drilling.
4. The percussion drill bit of claim 1 wherein the drill bit operating range for machine torque pressure is between about 8 to 15 Bar, and the machine thrust pressure setting for drill bit operation is set between about 12 and 20 Bar during a drilling operation.
5. The percussion drill bit of claim 4 wherein the drill bit operation for optimal percussion drilling provides a machine torque pressure setting at 12 Bar, and the machine thrust pressure setting at 15 Bar.
6. The percussion drill bit of claim 1 wherein the drill bit is formed of a double chisel design, and the bit body has a gauge diameter between about 1 to 2.
7. The percussion drill bit of claim 1 wherein said drill bit is formed of a modified double chisel design, and said drill bit body has a gauge diameter of between about 2 to 3.
8. The percussion drill bit of claim 6 wherein the drill bit of double chisel design comprises four PCD inserts provided upon the beveled face, and two PCD inserts fitted within the frontal face.
9. The percussion drill bit of claim 6 wherein the drill bit of double chisel design comprises four PCD inserts provided upon the beveled face, and at least one PCD insert fitted within the frontal face.
10. The percussion drill bit of claim 7 wherein said drill bits of a modified double chisel design comprising between four to six PCD inserts mounted in the beveled face, and from two to four PCD inserts mounted within the frontal face.
11. The percussion drill bit of claim 8 wherein the first and second sets of PCD inserts each comprising at least three PCD inserts.
12. The percussion drill bit of claim 10 wherein the first and second sets of PCD inserts each comprise at least four PCD inserts.
13. The percussion drill bit of claim 1 wherein the polycrystalline diamond coating of each tip of each conical and chisel insert is 0.010-0.030 thick.
14. The percussion drill bit of claim 19 wherein the radius of the center axis of the drill bit for each PCD insert provided within the frontal face is as set forth in the following chart. TABLE-US-00009 Drill Bit Size No of face Inserts Distance from C/L 1-1 1 1 2 3/16- 5/16 2 2 - 7/16 2 2 - 7/16 2 3 - 7/16- 3.0 4 -- 13/16-1.0 3
15. The percussion drill bit of claim 1 wherein each insert provided within the drill bit body having dimensions within ranges as set forth as follows: TABLE-US-00010 Range Claimed for Inserts Range Dimensions OAL of Insert .500-.650 Diameter of Insert .3000-.4200 Tip Length .200-.260 Tip Angle 15.00-35.00 Tip Radius .100 R-.145 R Grip Length .290-.420
16. The percussion drill bit of claim 1 wherein each insert provided within the drill bit body having dimensions within ranges as set forth as follows: TABLE-US-00011 Range Claimed for Inserts Range Dimensions OAL of Insert .600-.785 Diameter of Insert .3900-.4900 Tip Length .250-.350 Tip Angle 15.00-35.00 Tip Radius .120 R-.155 R Grip Length .300-.450
17. The percussion drill bit of claim 1 wherein each insert provided within the drill bit body having dimensions within the ranges as set forth as follows: TABLE-US-00012 Range Claimed for Inserts Range Dimensions OAL of Insert .625-.785 Diameter of Insert .4800-.5200 Tip Length .260-.335 Tip Angle 25.00-40.00 Tip Radius .135 R-.170 R Grip Length .330-.500
18. The percussion drill bit of claim 1 wherein each PCD chisel insert provided within the drill bit body having dimensions within the ranges as set forth as follows: TABLE-US-00013 Preferred Ranges Claimed for PCD Chisel Inserts PCD Insert Diameter range .300 to .750 PCD Insert grip length .300 to .600 PCD Insert tip length .250 to .360 PCD Tip radius on Chisel Inserts .04 to .135 PCD Tip length in a range of .225 to .375 PCD Coating thickness on Tip of inserts .010 to .035
19. A percussion drill bit, said drill bit formed having a body, the body capable of being secured with a drill shaft in preparation for a percussion drilling operation, the body having a cutting face, the body and the cutting face being integrally formed; the drill bit formed of a double chisel design or modified double chisel design configuration; said drill bit capable of operating at a machine torque pressure of less than 20 Bar, and a machine thrust pressure of less than 20 Bar; said frontal face of the drill bit having a series of openings provided therein, and PCD inserts being pressed fitted within said openings in preparation for usage of the drill bit in said drilling operation, there being at least two PCD inserts provided within the frontal face of the drill bit; each of said PCD inserts having a tip comprising a polycrystalline diamond coating; said inserts being arranged at a cutting angle of between about 0 to 45 off of the arc of rotation of the drill bit during performance of a drilling operation; each PCD insert provided in the cutting face of the drill bit positioned at a select radius from the center axis of said bit body; said drill bit body having a gauged diameter between about 1 to 3; each of the inserts being of a polycrystalline chisel design; and each insert having a gripping portion of a diameter between about 0.300 to 0.520, each insert having a grip length of between about 0.290 and 0.550, and each tip of each insert having a length of between about 0.200 and 0.320, and a conical surface at the tip of its formed chisel for each insert.
20. The percussion drill bit of claim 19 wherein the frontal face of the percussion drill bit is contoured into an outer beveled design, each beveled portion extending outwardly from the center of the drill bit, and having at least one chisel insert provided therein.
21. A percussion drill bit, said drill bit formed having a body, the body capable of being secured with a drill shaft in preparation for a percussion drilling operation, the body having a center axis and a cutting face, said cutting face having a front face and a beveled face outwardly of the frontal face, the body and the cutting face being integrally formed; said drill bit having a series of PCD inserts provided upon its frontal face, select of said PCD inserts being of a chisel design, and said PCD inserts having a tip, and the tip having a coating of polycrystalline diamond; said drill bit capable of operating at a machine torque pressure of 20 Bar or less, and a machine thrust pressure of 20 Bar or less; said chisel design inserts being arranged at a angle between about 0 to about 45 within the drill bit to provide for one of a plowing or slicing action of the drill bit when cutting of the earth during a percussion drilling operation; said drill bit body having a diameter between about 1 inches to 8 inches in diameter; and said percussion drill bit provided for drilling into hard rock and high silica ground during performance of a percussion drilling operation.
22. The percussion drill bit of claim 21, wherein all of said inserts are of a PCD chisel design.
23. The percussion drill bit of claim 21, wherein select of said inserts are of a PCD conical design.
24. The percussion drill bit of claim 21, wherein the inserts provided upon the frontal face of the drill bit function to drill the pilot hole within the earth during a percussion drilling operation, and the inserts provided upon the outer beveled portion of the drill bit are provided for furnishing a reaming of the drilled hole during performance of a percussion drilling operation, and wherein said inserts provided upon front face of the bit extending more forwardly than the inserts provided upon the beveled portion of the drill bit.
25. The percussion drill bit of claim 21, wherein said PCD chisel inserts have the following range of dimensions: TABLE-US-00014 PCD Insert diameter range .300 to .750 PCD Insert grip length .300 to .600 PCD Insert tip length .250 to .360 PCD Tip radius on Chisel Inserts .04 to .135 PCD Tip length in a range of .225 to .375 PCD Coating thickness on Tip of inserts .010 to .035 and said chisel inserts provided for one of plowing and slicing of the earth during the performance of a percussion drilling operation.
26. The percussion drill bit of claim 21, wherein the PCD conical inserts have the following range of dimensions: TABLE-US-00015 PCD Insert diameter range .300 to .750 PCD Insert grip length .300 to .600 PCD Insert tip length .250 to .360 PCD Tip radius on Conical Inserts .115 to .170 PCD Tip length in a range of .225 to .400 PCD Coating thickness on Tip of inserts .010 to .035
27. The percussion drill bit of claim 21, wherein the drill bits perform at low machine thrust pressures of 1.0 Bar to 20 Bar, and low machine torque pressures of 8 Bar to 20 Bar, and are used in combination with PCD chisel inserts and PCD conical inserts installed into the drill bit to maximize its percussion drilling performance.
28. The percussion drill bit of claim 21, wherein each drill bit at its smallest size is in the size range of approximately 1 and inches to 1 and inches in diameter.
29. The percussion drill bit of claim 21, wherein select of said PCD chisel inserts are linear aligned upon the cutting face of the drill bit, and other of said PCD inserts being linearly aligned at an offset angle from the linear alignment for the first set of chisel inserts when installed in the percussion drill bit.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0073] In referring to the drawings,
[0074] FIG. 1a through FIG. 1d shows, respectively, a side view, front view, and top view for the multi angle chisel design for a PCD insert;
[0075] FIG. 1e shows a side view of the insert, disclosing specific dimensions to its various angles upon its cutting tip;
[0076] FIG. 1f provides a transverse sectional view taken through the chisel bit along lines f-f of FIG. 1e;
[0077] FIG. 2a shows a top view of the application of a pair of PCD chisel inserts applied in a negative slicing angle within a percussion drill bit;
[0078] FIG. 2b provides a top view of the application of a pair of PCD chisel inserts into a percussion drill bit and arranged at a 0 angle to provide a plowing type of cutting of earth during usage.
[0079] FIG. 2c provides a top view of a pair of PCD inserts applied to a percussion drill bit and arranged at a positive slicing angle of approximately 10 when used in percussion drilling;
[0080] FIG. 2d provides a front view of a percussion drill bit having a pair of the PCD chisel inserts arranged along the double taper of the top of the shown drill bit;
[0081] FIG. 3 provides a top view of a drill bit incorporating a plurality of PCD chisel inserts primarily arranged in the plowing mode, with a single skewed insert provided for functioning in a slicing mode during percussion drilling;
[0082] FIG. 4a shows a percussion drill bit incorporating a series of PCD conical inserts;
[0083] FIG. 4b shows a top view of a percussion drill bit incorporating a series of PCD chisel type inserts;
[0084] FIG. 4c provides a side view of the percussion drill bit disclosed in FIG. 4b;
[0085] FIG. 5 provided a top view of a percussion drill bit having a frontal flat face and an integral beveled face incorporating a series of the PCD conical type inserts;
[0086] FIG. 6 is a top view of a percussion drill bit incorporating a series of the PCD chisel type inserts, select of most of said inserts being incorporated within the bit and arranged in a slicing mode;
[0087] FIG. 7 is a top plan view of a percussion drill bit having a frontal flat face and an integral beveled face extending outwardly therefrom, and incorporating a series of PCD chisel inserts primarily arranged for providing the slicing mode for percussion drilling;
[0088] FIG. 8 provides a top view of a percussion drill bit having a frontal flat face and an integral beveled face extending outwardly therefrom, and incorporating a series of combinations of PCD chisel inserts and PCD conical type inserts in its design;
[0089] FIG. 9, as previously reviewed, is a partial side view of a bit body showing its various parameters;
[0090] FIG. 10 provides a side view of an insert, of the polycrystalline diamond and conical design, for application to the front surface or cutting face of the bit body, as of FIGS. 5 and 8;
[0091] FIG. 11 shows a complete side view of a bit body disclosing its cutting face at one end, having both a frontal flat face and beveled face extending outwardly therefrom, and showing at least one of the discharged ports for the application of cleaning fluid, or water, used to flush out the drilled hole during percussion drilling;
[0092] FIG. 12a provides a top view of a conical insert for a percussion drill bit;
[0093] FIG. 12b shows a side view, partially cut away, of a conical insert having a polycrystalline diamond coating provided upon its upper surface; and
[0094] FIG. 13 shows a further side view, and the various dimensions, for the complete polycrystalline conical insert for a percussion drill bit, as used in this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0095] This invention provides an advancement to the art of percussion drilling, and adds to the concept of utilizing polycrystalline diamond percussion drill bits, where the various inserts are coated with a layer of PCD, in order to provide a far more durable cutting face for the bit, when it is used in percussion drilling within very hard soil, such as hard rock, or high silica ground. More specifically, this invention includes the application of inserts, into percussion drill bits, of a chisel type of design, which are polycrystalline diamond coated, and can be used in combination with PCD carbide conical tips, or a plurality of the chisel type of inserts, when applied to the drill bit, that can be used independently. In any event, in the use of the chisel type PCD inserts, whether alone, or in combination with the conical PCD drill bits, the percussion drilling operation is far more efficient, much more durable for long lasting life of the bits, and in addition, can be operated at much lower torque and thrust pressures, than when the standard type of carbide inserts are used in drill bits, for related drilling operations.
[0096] More specifically, in referring to FIGS. 1a through 1d, a chisel type of PCD insert 20, can be seen. The insert includes the gripping portion 21, in its lower segment, and has an upper contoured tip 22 which, as can be seen in FIG. 1b, has a pair of inclined surfaces, one as shown at 23, as noted in FIG. 1c. There are a pair of such inclined surfaces, as at 23 and 24, which incline upwardly, towards an upper widened vertex, as can be noted at 25, and which generally extends from side to side across the top of the insert, as seen in FIG. 1c. At the bottom 26 of the gripping portion 21, there is a slight bevel or radius, as noted, and this is to facilitate the insertion of the inserts into the drill bit, when the bit is being assembled, for use for a drilling operation. The various parameters for the PCD chisel and conical insert, when used in the form of a chisel insert, as at 20, in the preferred embodiments, can have the following range of dimensions:
TABLE-US-00007 Insert Parameters for PCD Conical and Chisel Type Percussion Drill Bit Applications PCD Insert diameter range .300 to .750 PCD Insert grip length .300 to .600 PCD Insert tip length .250 to .360 PCD Tip radius range Conical Inserts .125 to .170 PCD Tip radius range Chisel Inserts .04 to .135 PCD tip length in a range of .225 to .375 PCD Coating thickness on Tip of Inserts. .010 to .035
[0097] A typical example of the dimensions for the specifically applied chisel form of insert, can be seen in FIGS. 1e and 1f. As can be noted, it includes its base portion 21, its top portion 22, and it is this top portion that is coated with the polycrystalline diamond material, and generally the coating thickness is to that range as previously explained, approximately 0.010 to 0.035, in its application. And, in this embodiment, the top edge 25 extends transversely across the width of the insert, and it may have slightly inclined side edges, as at 27 and 28, in order to eliminate any sharpened edges that may possibly wear quicker during usage of the drill bit in which these chisel inserts locate, for percussion drilling usage.
[0098] In the application of these PCD chisel inserts, within drill bits, their primary usage can be noted in FIGS. 2a through 2d. As noted, as in FIG. 2a, the drill bit 29 contains a pair of PCD chisel inserts, as noted at 30 and 31. In this particular instance, the upper ridge or vertex of the inserts, as at 25, are arranged on an angle with respect to the radial dimension of the insert, and in this instance, the radial dimension would be the perpendicular radius to the outer arc of rotation of the drill bit, and as noted, the chisel inserts are arranged at a negative slicing angle of approximately 10, off the radius, as shown. This means when the drill bit is rotated in the clockwise direction, the slicing of the earth due to the percussion impacting of the drill bit into the earth will generally force the debris towards the outer edge of the bit, as can be understood.
[0099] On the other hand, as can be seen in FIG. 2c, the chisel inserts are arranged, in this embodiment, in a positive 10 angle, off of the radius of the bit, and therefore furnishes a positive slicing action into the earth, when the drill bit is impacted and rotated in the clockwise direction, during a percussion drilling operation, and therefor, the chisel upper surface 25 has a tendency to not only ground into the hard rock, but as it does so, urges any debris inwardly, when the drill bit is continued in its rotation in that clockwise direction, during percussion drilling operations.
[0100] This is all distinguish from the use of the chisel inserts, as noted in FIG. 2b, the upper edges of the chisel inserts are arranged along the radius of the drill bit 29 as can be seen. Thus, there is 0 angle between the installed chisel inserts, within the bit body, and thus, the chisel inserts simply plow the surface of the ground being drilled, does not have a tendency to achieve any slicing of the earth, or its movement, other than simply through a plowing action when the bit body is still rotated in its clockwise direction.
[0101] FIG. 2d shows an example of the bit body 32 of one design, where the upper surface of the bit body is formed of approximately three surfaces, a center flat surface 33 and a pair of integral inclined surfaces 34 and 35 and into which the chisel type of inserts 30 and 31 are inserted and installed within the drill bit 32.
[0102] Once again, all of these various chisel inserts, regardless to what angle they are applied within their drill bit body, are coated, upon their tip length, as previously summarized at 6, with the polycrystalline diamond composition, to add to the hardness of the drill bit, through its usage of PCD inserts, of the types as previously described, whether they be of the chisel type, or the conical form of insert.
[0103] An example of the application of the chisel form of PCD inserts to the drill bits, can be noted in FIG. 3. This is an example of an array of chisel type inserts applied to the frontal surface 36 of the shown drill bit. As noted, a series of the inserts that locate along the outer perimeter of the drill bit can be seen at 37 through 40. As noted, these particular inserts are arranged at approximately a perpendicular angle to the arc of rotation of the bit, and pairs of them, as 37 and 39, and 38 and 40, are arranged linearly, as noted at 41 and 42, and the inserts are arranged in a plowing mode, rather than slicing mode, when used in a drilling operation. The plowing mode means that the upper transverse edge, one as shown at 43, is arranged 90 from the direction of rotation of the drill bit, during its application and usage. Thus, the edge of the insert does not slice the hardened ground, but rather, impacts it due to the percussion drilling, and then simply plows the debris forwardly, in order to achieve further cutting of the rock, in its pushing forwardly, during the rotation of the drill bit. It has been found that the PCD chisel insert, when they angled at about a 30 angle, apart from the vertical, as noted, or approximately at that perpendicular angle with respect to the arc of rotation, and thus are further arranged approximately 60 apart from each other, as noted, from the direction of rotation.
[0104] As can further be noted, an additional PCD chisel insert 44 is provided, and it is arranged at an angle of approximately 15, from the perpendicular, in order to reduce the torque pressure on the insert and have the insert cutting action in a slicing type of mode, for drilling.
[0105] FIG. 4a shows another embodiment for a PCD drill bit 45, in this particular instance, being 5 inserts located strategically around the surface of the bit, both on its frontal flat face 46, and its beveled peripheral edges, as at 47, and includes the PCD conical type of insert design, as noted at 48. There is an additional conical insert 49 provided upon the frontal flat face of the drill bit, while the remaining conical inserts locate upon its beveled edges. There is also at least one fluid flush hole 50 through which the cleansing fluid, such as water under pressure, discharges into the vicinity of the face of the drill bit, during a percussion drilling operation, in order to remove the fractured debris, in the manner as previously explained.
[0106] It might be summarized, once again, at this time, that the various types of PCD conical inserts provided within the frontal face of the drill bit, in practical application, may have the following range of dimensions, in their structure.
TABLE-US-00008 Insert Parameters for PCD Conical and Chisel Type Percussion Drill Bit Applications PCD Insert Diameter range .300 to .750 PCD Insert grip length .300 to .600 PCD Insert tip length .250 to .360 PCD Tip radius Range Conical Inserts .125 to .170 PCD Tip radius Range Chisel Inserts .04 to .135 PCD tip length in a range of .225 to .375 PCD Coating thickness on Tip of Inserts .010 to .035
[0107] FIG. 4b shows a related type of percussion drill bit 51, but in this particular instance, it contains a plurality of the chisel type PCD inserts, as noted at 52. These inserts are generally arranged and provided along the outer beveled surface 53, and generally are set in the plowing mode, since the angle of their upper cutting edges, as at 54, are generally arranged at the perpendicular to the arc of rotation of the drill bit, during usage, and are a further arranged in alignment with the radius from the center of the drill bit, as can be noted. There is a further chisel PCD insert 55 that is provided within the upper flattened face 56 of the drill bit, and this particular insert, and its upper transverse cutting edge 57 will be arranged at various angles with respect to the perpendicular to the arc of rotation of the bit, in order to place this particular insert into a plowing mode. Hence, it has been found desirable to arrange this particular insert, at an angular disposition with respect to said perpendicular, between about 0, which would be in a plowing mode, and up to approximately 45, which would furnish the ultimate slicing mode for this particular insert, when applied within the percussion drill bit, during a drilling operation. The aperture 58, once again, is provided for delivering cleansing fluid such as water under pressure, to the face of the drill bit, during a percussion drilling operation.
[0108] FIG. 4c shows a side view of the chisel PCD inserts, such as 52, provided within the beveled outer surface of the drill bit, and the insert 55 that is provided extending from the frontal flat face 56, of the shown bit body 59.
[0109] It might be stated at this time that the usage of the various inserts in the drill bits, such as shown in FIGS. 4a, and subsequently in FIGS. 5 and 6, all have select either conical or chisel type of inserts provided upon the frontal flat face of the shown drill bits. And, there are also either conical or chisel inserts that are provided upon the outer beveled surfaces of the front face of the drill bits, as can be noted. In effect, when these types of bits, with their shown inserts, are applied, at these angular installations, those inserts provided upon the upper flat face of the bit function in a drilling action to initiate the cutting of the pilot hole at the center of the drilled hole, and then the outer inserts applied to the beveled surfaces of the bits function to ream the rock, into a refined drilled hole, during usage of these PCD percussion drill bits. It is believed this occurs because the inserts in the frontal flat face of the drill bits are actually higher or extend further upwardly from the inserts provided upon the beveled faces, and therefore, one does function a means for drilling the pilot hole, while the outer gauge inserts function for reaming the rock to the piloted center cut.
[0110] FIG. 5 show the application of a series of PCD conical inserts 60 and 61 applied to the beveled portion 62 of the drill bit, and also to the frontal flat face 63, respectively. It is to be noted that the conical inserts generally have slightly different dimensions from the center point 64 of the shown bit, in order to lesson tracking of the cutting achieved by the various inserts, during a percussion drilling operation.
[0111] FIG. 6 provides a top view of the percussion drill bit 64 having a series of PCD chisel inserts 65 and 66 provided, respectively, upon the outer beveled surface 67 and the frontal flat face 68 of the shown drill bit, as previously reviewed. As can be noted, the transverse upper cutting edges, as at 69, are slightly angulated, at a small degree, off of the perpendicular from the arc of rotation of the drill bit, in order to initiate the functioning of the insert into a slight slicing mode, particular with respect to those inserts 65 provided upon the outer beveled surface. But, the transverse upper cutting edges 70 of those inserts applied to the frontal flat face 68 of the bit are arranged at much greater angles, approximately 30, as shown, in order to provide full slicing through the application of the bit when impacting upon the hardened earth, during performance of a percussion drilling operation.
[0112] FIG. 7 shows the usage of a plurality of the PCD chisel type inserts, as at 71, applied to the outer beveled surface 72 of the drill bit 73. And, most of these inserts, and more specifically their upper transverse cutting edges 74, are arranged in a slicing mode, being offset a few degrees from the perpendicular to the arc of rotation of the drill bit, during its usage. As can be seen, most of these upper edges, as noted at 75, are arranged a few degrees, approximately 10, off of the perpendicular to the arc of rotation of the bit, during usage. In this manner, these inserts function in a slight slicing mode when impacting the hardened earth during a percussion drilling operation. They push the debris outwardly of the shown bit. As can also be seen, for the flat frontal face 76 for the drill bit, the PCD chisel type inserts 77, are located within the bit body, at various locations, and at more significant angles from the perpendicular to the arc of rotation, of the drill bit, when used. For example, it can be seen that the transverse upper cutting edge 78 for one of the inserts 77 is at an approximate 30 angle from the perpendicular to the arc of rotation, as are the transverse cutting edges 79 and 80 for the shown inserts, which are clearly deployed in the surface of the drill bit in the slicing mode of usage. And, as can be noted, there are just no vertical planes of symmetry that pass through the central axis of the bit body, with respect to each of these applied PCD chisel type inserts, particularly those that are arranged within the frontal flat face 76, of the shown drill bit. Furthermore, as can be noted, many of the inserts 77 installed within the flat face 76 of the drill bit are at a different radii from the center 81 of the bit body, and therefore, avoids tracking of any of these inserts relative to the other during performance of a percussion drilling operation. In other words, each insert does its own slicing of the ground, independently of the other inserts, in order to greatly enhance the efficiency of the drilling operation, when performed. In addition, in order to maximize flushing of any cuttings from the drilled earth, there are a series of apertures 82 for delivering water under pressure to the front surface of the drill bit, during a percussion drilling operation.
[0113] FIG. 8 discloses a percussion drill bit 83 where a combination of PCD chisel type inserts, as at 84, are used in combination with a series of PCD conical inserts 85, as can be noted. This type of drill bit, containing this many inserts, is generally structured in the four inch through 8 inch percussion type, and down the hole hammer drill bit, such as 83, as noted. Any combination of the conical and chisel designed PCD inserts are employed, and it is believed that this is the first time that such a combination has been structured. A similar type of relationship of a combination of chisel type inserts 86, and a series of PCD conical type inserts 87 are also applied to the frontal flat face 88 of the shown drill bit. You should note that most if not all of the transverse cutting edges 89 are arranged in a slicing mode, generally between slightly more than 0, and up to 45, with respect to the perpendicular from the arc of rotation of the drill bit, when employed. This provides that slicing type of cutting of the harden earth, during usage of the percussion drill bit, when performing a drilling operation. You should also note that many of the various inserts, whether of the PCD chisel type, or the PCD conical type, are arranged at differing distances along the radii from the center of the drill bit, in order to, once again, avoid tracking of one bit in its cutting function from overlapping the operations of another insert, during percussion drilling. And, the water apertures 90 are provided for flushing of the debris during a drilling function. The asymmetrical design of the location of the various applied inserts, with respect to the center axis of the bit, is provided, in order to enhance the efficiency of the drilling operation. A drill bit, of this design, is designed to drill fast, and clear the hole of cuttings, than has heretofore been designed.
[0114] Variations or modifications to the subject matter of this invention may occur to those skilled in the art upon review of the disclosure as provided herein. Such changes or variations, if within the spirit of this invention, are intended to be encompassed within the scope of any claims issuing in this patent. The description of the invention as set forth herein, and its depicted in the drawings, are primarily set forth for illustrative purposes only.
