US20100032216A1 - Earth boring cutter employing helical teeth - Google Patents
Earth boring cutter employing helical teeth Download PDFInfo
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- US20100032216A1 US20100032216A1 US12/189,011 US18901108A US2010032216A1 US 20100032216 A1 US20100032216 A1 US 20100032216A1 US 18901108 A US18901108 A US 18901108A US 2010032216 A1 US2010032216 A1 US 2010032216A1
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- curved
- cutter
- tooth
- teeth
- earth bit
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- 238000005520 cutting process Methods 0.000 claims abstract description 34
- 230000007423 decrease Effects 0.000 description 72
- 230000015572 biosynthetic process Effects 0.000 description 33
- 238000005755 formation reaction Methods 0.000 description 33
- 230000003247 decreasing effect Effects 0.000 description 12
- 238000005096 rolling process Methods 0.000 description 12
- 238000005553 drilling Methods 0.000 description 6
- 239000000463 material Substances 0.000 description 6
- 235000019738 Limestone Nutrition 0.000 description 3
- 239000006028 limestone Substances 0.000 description 3
- 229910052500 inorganic mineral Inorganic materials 0.000 description 1
- 239000011707 mineral Substances 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
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Classifications
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- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B10/00—Drill bits
- E21B10/08—Roller bits
- E21B10/16—Roller bits characterised by tooth form or arrangement
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T407/00—Cutters, for shaping
- Y10T407/19—Rotary cutting tool
- Y10T407/1952—Having peripherally spaced teeth
- Y10T407/1954—Axially tapering tool
Abstract
An earth bit includes an earth bit body and a lug and cutting cone carried by the earth bit body, wherein the cutting cone is rotatably mounted to the lug. A plurality of cutters are carried by the earth bit body, wherein the cutters include a cutter body and a plurality of curved teeth extending between opposed ends of the cutter body. The curved teeth are positioned so that one end of a tooth overlaps an opposed end of an adjacent tooth. The curved teeth of a first cutter extend in a direction around its corresponding cutter body and the curved teeth of a second cutter extend in an opposed direction around its corresponding cutter body.
Description
- 1. Field of the Invention
- This invention relates generally to cutters for earth bits.
- 2. Description of the Related Art
- An earth bit is commonly used to bore holes into a formation. Such holes may be bored for many different reasons, such as drilling for oil, minerals and geothermal steam. There are several different types of earth bits that are used to bore holes. One type is a rotary earth bit and, in a typical setup, it includes three earth bit cutting cones rotatably mounted to a corresponding lug. The lugs are mounted on an earth bit body and, as the earth bit body is rotated in the bore hole, the earth bit cutting cones rotate in response to contacting the formation.
- Another type of earth bit is a rolling cutter earth bit which typically includes a number of saddles carried by an earth bit body. A cutter is coupled with the earth bit body by rotatably mounting it to a saddle. Each cutter includes a number of teeth for boring into the formation. Examples of rolling cutter earth bits are disclosed in U.S. Pat. Nos. 3,444,939, 4,040,493, 4,161,225, 4,167,980, 4,393,949 and 5,456,328.
- Most of these rolling cutter earth bits include cutters which are designed to bore through hard or medium hard formations, instead of soft formations such as soft limestone and soft-to-medium shale. Further, most of these rolling cutter earth bits include cutters which generate smaller cuttings. These rolling cutter earth bits typically include cutters which experience a significant amount of tracking, wherein the teeth of one cutter will follow in the path of the teeth of another cutter. It is desirable to reduce the amount of tracking because tracking reduces the operating life of the cutters and undesirably reduces the drilling efficiency of the earth bit.
- Hence, there is a need for a rolling cutter earth bit for boring through soft formations, wherein the rolling cutter earth bit includes cutters which experience less tracking. Further, there is a need for a rolling cutter earth bit which includes cutters that generate larger cuttings when boring through soft formations.
- The present invention provides a cutter, which includes a cutter body having opposed openings, and a plurality of curved teeth extending around the outer periphery, and between opposed ends, of the cutter body. The curved teeth have a curved edge, and a curved leading face that curves as it extends between opposed ends of the cutter body.
- The cutter can include many other features. For example, in some embodiments, the curved teeth are positioned so that one end of a curved tooth overlaps the opposed end of an adjacent curved tooth.
- In some embodiments, the opposed ends of each curved tooth have different dimensions from each other. In some embodiments, the curved teeth include a curved leading face that curves as it extends between opposed ends of the cutter body. The plurality of curved teeth can include at least one curved tooth having first and second tooth portions spaced apart from each other. In some embodiments, the plurality of curved teeth includes first and second notched curved teeth. The notches of the first and second notched curved teeth can be offset from each other. In some embodiments, the plurality of curved teeth includes an unnotched curved tooth.
- The invention provides an earth bit, which includes an earth bit body and a first cutter rotatably mounted to the earth bit body with a first saddle. The first cutter includes a cutter body, and a first plurality of curved teeth extending in a direction around the outer periphery, and between opposed ends, of the cutter body. The curved teeth are positioned so that one end of a curved tooth overlaps an opposed end of an adjacent curved tooth.
- The earth bit can include many other features. For example, in some embodiments, the dimensions of a curved tooth at its end surface are smaller than the dimensions of the curved tooth at its opposed end surface. The curved teeth can include a curved edge and a curved face that curves as it extends away from the curved edge. In some embodiments, the first plurality of curved teeth includes at least one curved tooth having first and second tooth portions spaced apart from each other.
- In one embodiment, the earth bit further includes a second cutter rotatably mounted to the earth bit body with a second saddle. The second cutter includes a cutter body and a second plurality of curved teeth extending between opposed ends and in an opposed direction around the outer periphery of the cutter body. The curved teeth of the second cutter are positioned so that one end of a curved tooth overlaps the opposed end of an adjacent curved tooth. In some embodiments, the number of curved teeth of the first and second cutters are the same. The first and second saddles can be offset from each other.
- In some embodiments, the earth bit further includes a third cutter rotatably mounted to the earth bit body with a third saddle. The third cutter includes a cutter body and a third plurality of curved teeth extending between opposed ends and in the direction around the outer periphery of the cutter body. The curved teeth of the third cutter are positioned so that one end of a curved tooth overlaps the opposed end of an adjacent curved tooth. In this embodiment, the second cutter is positioned between the first and third cutters.
- The invention provides an earth bit, which includes an earth bit body, and a lug and cutting cone carried by the earth bit body, wherein the cutting cone is rotatably mounted to the lug. The earth bit includes a plurality of cutters carried by the earth bit body, wherein the cutters include a cutter body and a plurality of curved teeth extending between opposed ends of the cutter body. The curved teeth are positioned so that one end of a tooth overlaps an opposed end of an adjacent tooth. The curved teeth of a first cutter extend in a direction around its corresponding cutter body and the curved teeth of a second cutter extend in an opposed direction around its corresponding cutter body.
- The earth bit can include many other features. For example, in some embodiments, a tooth of the first cutter includes first and second tooth portions spaced apart from each other. In some embodiments, the dimensions of a curved tooth of the first cutter at its opposed end surfaces are different.
- In some embodiments, the earth bit includes a third cutter having teeth which extend in the same direction as the teeth of the first cutter, wherein the second cutter is positioned between the first and third cutters. In these embodiments, the second cutter is offset from the first and third cutters to reduce the amount of tracking experienced by the teeth of the cutters.
- Further features and advantages of the invention will be apparent to those skilled in the art from the following detailed description, taken together with the accompanying drawings.
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FIGS. 1 a, 1 b and 1 c are perspective, side and end views, respectively, of a cutter having a frusto-conical cutter body and straight teeth. -
FIG. 2 a is a perspective view of a cutter, in accordance with the invention, having unnotched curved teeth. -
FIGS. 2 b and 2 c are opposed end views of the cutter ofFIG. 2 a. -
FIG. 2 d is a close-up end view of the cutter ofFIG. 2 a. -
FIGS. 3 a and 3 b are perspective and side views, respectively, of a cutter, in accordance with the invention, having notched curved teeth. -
FIGS. 3 c and 3 d are opposed end views of the cutter ofFIG. 3 a. -
FIGS. 3 e and 3 f are close-up end and side views, respectively, of the cutter ofFIG. 3 a. -
FIGS. 4 a and 4 b are perspective and side views, respectively, of a cutter, in accordance with the invention, having notched curved teeth. -
FIGS. 4 c and 4 d are opposed end views of the cutter ofFIG. 4 a. -
FIGS. 4 e and 4 f are close-up end and side views, respectively, of the cutter ofFIG. 4 a. -
FIGS. 5 a and 5 b are bottom perspective and bottom views, respectively, of an embodiment of a rolling cutter earth bit, in accordance with the invention. -
FIGS. 6 a and 6 b are bottom perspective and bottom views, respectively, of another embodiment of a rolling cutter earth bit, in accordance with the invention. - The present invention provides a cutter, and an earth bit which employs the cutter, for boring through soft formations. The cutter, in accordance with the invention, includes teeth that generate large cuttings when boring through the soft formations. Further, the earth bit, in accordance with the invention, includes a plurality of such cutters positioned to reduce the amount of tracking experienced by the teeth of the cutters. The operating life of the cutters and the drilling efficiency of the earth bit both increase in response to reducing the amount of tracking experienced by the teeth. It should be noted that the cutters disclosed herein can be interchanged with other types of cutters, such as those used to bore through hard and medium hard formations (i.e. formations that are harder than soft limestone and soft-to-medium shale). Hence, the cutters of the earth bit are interchangeable so that the earth bit can be modified to improve its ability to bore through soft, medium hard and hard formations.
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FIG. 1 a is a perspective view of acutter 100 having a frusto-conical cutter body 101 and astraight tooth 103, andFIGS. 1 b and 1 c are side and end views, respectively, ofcutter 100. In this embodiment,cutter 100 includes acentral opening 102 which extends throughcutter body 101 and between opposed ends 106 a and 106 b.Cutter body 101 has a smaller outer diameter atend 106 a than atend 106 b. In this way,cutter body 101 has a frusto-conical shape. - In this embodiment,
central opening 102 has the same shape and dimension at ends 106 a and 106 b and is sized and shaped to receive a shaft (not shown), so thatcutter 100 can be rotatably mounted to an earth bit.Cutter 100 can be rotatably mounted to the earth bit in many different ways. In some embodiments, the earth bit includes a saddle and shaft, andcutter 100 is rotatably mounted to the saddle by extending the shaft throughcentral opening 102. The shaft extends through opposed ends ofcentral opening 102. More information regarding earth bits is provided withFIGS. 5 a and 5 b andFIGS. 6 a and 6 b. - In this embodiment,
straight tooth 103 extends along the outer periphery ofcutter body 101 and between opposed ends 106 a and 106 b. In general,cutter 100 can include any number of straight teeth, but it includes thirteen straight teeth here for illustrative purposes. In some embodiments, the number of teeth ofcutter 100 is in a range between about seven and nineteen because this number of teeth has been found to be useful when boring through soft formations, such as soft limestone and soft-to-medium shale. Further, this number of teeth is useful to generate cuttings of a desired size when boring through soft formations. Hence, the size of the cuttings can be controlled by controlling the number of teeth included withcutter 100. - In this embodiment,
straight tooth 103 includes aflat face 104 andstraight edge 105, whereinflat face 104 andstraight edge 105 do not curve between ends 106 a and 106 b. In this way,tooth 103 is a straight tooth with a flat face. The flatness and straightness offlat face 104 andstraight edge 105 can best be seen in the side and end views ofFIGS. 1 b and 1 c, respectively. It should be noted that the length ofstraight tooth 103 typically corresponds with the length ofstraight edge 105. Hence, the length ofstraight tooth 103 increases and decreases as the length ofstraight edge 105 increases and decreases, respectively. - In this embodiment,
straight tooth 103 includes opposedsurfaces 116 a (FIG. 1 a) and 116 b (FIG. 1 b) positioned proximate to ends 106 a and 106 b, respectively.Flat face 104 andstraight edge 105 do not curve betweensurfaces tooth 103 is a straight tooth with a flat face. Incutter 100,surfaces surfaces surface 116 a has the same area assurface 116 b. - In
FIG. 1 c, aradial line 109 extends radially and outwardly from acenter 108 ofcutter body 101.Straight edge 105 extends between opposed ends 106 a and 106 b so that it is perpendicular toradial line 109. Further,straight edge 105 extends betweenopposed surfaces radial line 109.Radial line 109 extends so that it bisects opposedsurfaces straight tooth 103.Radial line 109 bisects surface 116 a because the shape and area ofsurface 116 a is the same on opposed sides ofradial line 109. Further,radial line 109 bisectssurface 116 b because the shape and area ofsurface 116 b is the same on opposed sides ofradial line 109.Straight edge 105 bisectssurfaces radial line 109, andtooth 103 is a straight tooth. - It should be noted that
radial line 109 can be positioned, without changing its angle relative tocutter body 101 andcenter 108, at any location ofcutter body 101 betweensurfaces straight edge 105. For example,radial line 109 is shown as being proximate tosurfaces FIG. 1 a, wherein it intersectsstraight edge 105 proximate tosurfaces radial line 109 can intersectstraight edge 105 at any position betweensurfaces cutter body 101 andcenter 108. Hence, the same radial line (i.e. radial lines oriented at the same angle) extends through the intersection ofstraight edge 105 withopposed surfaces -
FIG. 2 a is a perspective view of acutter 110, in accordance with the invention, andFIGS. 2 b and 2 c are opposed end views ofcutter 110.Cutter 110 is similar tocutter 100 discussed above, and includescutter body 101 withcentral opening 102. However, in accordance with the invention,cutter 110 includes an unnotchedcurved tooth 113 which extends in adirection 107 a between opposed ends 106 a and 106 b and along the outer periphery ofcutter body 101.Direction 107 a is in a clockwise direction when looking towardsend 106 a (FIG. 2 b) anddirection 107 a is in a counterclockwise direction when looking towardsend 106 b (FIG. 2 c).Cutter 110 can include any number of unnotched curved teeth, but it includes thirteen unnotched curved teeth here for illustrative purposes. In some embodiments, the number of unnotched curved teeth ofcutter 110 is in a range between about seven and nineteen for reasons mentioned above. - In this embodiment, unnotched
curved tooth 113 includes acurved face 114 andcurved edge 115, whereincurved face 114 andcurved edge 115 curve between ends 106 a and 106 b. Further,curved face 114 curves as it extends away fromcurved edge 115. In this way,curved tooth 113 is a curved tooth with a curved face. Hence,curved tooth 113 is not a straight tooth with a flat face, liketooth 103 discussed above. The curvature ofcurved face 114 andcurved edge 115 can be seen inFIGS. 2 a, 2 b and 2 c. It should be noted thatcurved face 114 is a curved leading face because it engages the formation in response to the rotation ofcutter 110 indirection 107 a. - In this embodiment, unnotched
curved tooth 113 includes opposedsurfaces 116 a (FIG. 2 b) and 116 b (FIG. 2 c) positioned proximate to ends 106 a and 106 b, respectively.Curved face 114 andcurved edge 115 curve betweensurfaces tooth 113 is a curved tooth with a curved face. Incutter 110,surfaces surfaces cutter 110 are typically different from each other. For example, in one embodiment,surface 116 a is shaped like an equilateral triangle andsurface 116 b is not shaped like an equilateral triangle. In another embodiment,surface 116 a is shaped like an isosceles triangle andsurface 116 b is not shaped like an isosceles triangle. In one embodiment,surface 116 a is shaped like an equilateral triangle andsurface 116 b is shaped like an isosceles or scalene triangle. In another embodiment,surface 116 a is shaped like an isosceles triangle andsurface 116 b is shaped like an equilateral or scalene triangle. In this way, the shapes ofsurfaces cutter 110 are different from each other. It should be noted that, inFIGS. 2 b and 2 c, surfaces 116 a and 116 b are shaped like isosceles and scalene triangles, respectively. - The dimensions of
surfaces cutter 110 are typically different from each other. As mentioned above, the dimensions ofsurfaces surface 116 a has a smaller area thansurface 116 b. - In
FIG. 2 b and 2 c,radial lines center 108 ofcutter body 101, whereinradial lines Radial line 109 a extends so that it intersects the intersection ofcurved edge 115 and surface 116 a, andradial line 109 b extends so that it intersects the intersection ofcurved edge 115 andsurface 116 b.Radial line 109 a extends so that it bisectssurface 116 a (FIG. 2 b) because the shape and area ofsurface 116 a oftooth 113 is the same on opposed sides ofradial line 109 a.Radial line 109 abisects surface 116 a whensurface 116 a has a shape like an equilateral or isosceles triangle.Radial line 109 b extends so that it does not bisectsurface 116 b (FIG. 2 c) because the shape and area ofsurface 116 b oftooth 113 is not the same on opposed sides ofradial line 109 b.Radial line 109 b extends so that it does not bisectsurface 116 b when the shape ofsurface 116 b is not an equilateral or isosceles triangle.Radial line 109 b extends so that it does not bisectsurface 116 b when the shape ofsurface 116 b is a scalene triangle. Hence,surface 116 a is symmetrical withradial line 109 a andsurface 116 b is non-symmetrical withradial line 109 b. - In this embodiment,
curved edge 115 curves betweenradial lines Curved edge 115 is curved so thatradial lines FIGS. 2 b and 2 c. Angle θ1 is nonzero so that the same radial line does not extend through the intersections ofcurved edge 115 andopposed surfaces cutter 100. - Angle θ1 can have many different angular values. For example, in one embodiment, angle θ1 is less than about twenty degrees and, in another embodiment, angle θ1 is less than about fifteen degrees. In one particular embodiment, angle θ1 is between about two degrees and fifteen degrees. In another particular embodiment, angle θ1 is between about five degrees and twenty degrees.
- In general, the amount of curvature of
tooth 113 increases and decreases as the magnitude of angle θ1 increases and decreases, respectively. The amount of curvature ofcurved face 114 andcurved edge 115 increases and decreases as the magnitude of angle θ1 increases and decreases, respectively. Further, the amount of twist oftooth 113 increases and decreases as the magnitude of angle θ1 increases and decreases, respectively. As the amount of twist oftooth 113 increases and decreases, the amount of twist ofcurved face 114 andcurved edge 115 increases and decreases, respectively. In this way, the amount of curvature and twist oftooth 113 is adjustable in response to adjusting the magnitude of angle θ1. - In general, the length of unnotched
curved tooth 113 increases and decreases as the magnitude of angle θ1 increases and decreases, respectively. The length of unnotchedcurved tooth 113 typically corresponds with the length ofcurved edge 115. The length of unnotchedcurved tooth 113 increases and decreases as the length ofcurved edge 115 increases and decreases, respectively. Hence, the length ofcurved edge 115 increases and decreases as the magnitude of angle θ1 increases and decreases, respectively. - It should be noted that the curvature of unnotched
curved tooth 113, for a constant angle θ1, typically increases and decreases as the length ofcurved edge 115 decreases and increases, respectively. Further, the curvature of unnotchedcurved tooth 113, for a constant length ofcurved edge 115, typically increases and decreases as angle θ1 increases and decreases, respectively. -
FIG. 2 d is a close-up end view ofcutter 110 looking towardsend 106 a, as inFIG. 2 b. In accordance with the invention, the unnotched curved teeth ofcutter 110 overlap each other. The unnotched curved teeth ofcutter 110 can overlap each other in many different ways. As shown inFIG. 2 d,cutter 110 includes unnotchedcurved teeth Curved teeth curved tooth 113 discussed above.Curved tooth 113 a includescurved face 114 a andcurved edge 115 a, andcurved tooth 113 b includescurved face 114 b andcurved edge 115 b.Radial line 109 a extends betweencenter 108 ofcutter body 101 and the intersection ofsurface 116 a oftooth 113 a andcurved edge 115 a. Further,radial line 109 b extends betweencenter 108 ofcutter body 101 and the intersection ofsurface 116 b ofcurved tooth 113 a andcurved edge 115 a. Aradial line 109 c extends betweencenter 108 ofcutter body 101 and the intersection ofsurface 116 a oftooth 113 b andcurved edge 115 b. As mentioned above,radial lines radial lines radial lines radial line 109 b is proximate to end 106 b. - In accordance with the invention,
curved teeth curved teeth curved teeth curved edge portion 117 b ofcurved edge 115 b overlaps acurved edge portion 117 a ofcurved edge 115 a.Curved edge portions radial lines curved teeth curved edges cutter 110 includes unnotched curved teeth which overlap each other. - Angle θ1 is greater than angle θ2 so that a
curved surface portion 118 b ofcurved surface 114 b overlaps acurved surface portion 118 a ofcurved surface 114 a.Curved surface portions radial lines Curved surface portion 118 a is bounded betweenradial lines curved edge portion 117 a andsurface 116 b oftooth 113 a. Further,curved surface portion 118 b is bounded betweenradial lines curved edge portion 117 b and surface 116 a oftooth 113 b. Hence,curved teeth curved surfaces cutter 110 includes unnotched curved teeth which overlap each other. - The amount of overlap of
curved teeth curved surface 114 a. Further, the difference between angles θ1 and θ2 can be increased by increasing the curvature ofcurved edge 115 a. The difference between angles θ1 and θ2 can be decreased by decreasing the curvature ofcurved surface 114 a. Further, the difference between angles θ1 and θ2 can be decreased by decreasing the curvature ofcurved edge 115 a. In this way, the amount of overlap ofcurved teeth curved surface 114 a andcurved edge 115 a. - It should be noted that
curved teeth curved teeth cutter 110 provides an improved cutting efficiency whenteeth curved teeth cutter 110 provides an improved cutting efficiency when angle θ1 is between zero degrees and five degrees less than angle θ2. In some embodiments,cutter 110 provides an improved cutting efficiency when angle θ1 is between zero degrees and ten degrees less than angle θ2. In some embodiments,cutter 110 provides an improved cutting efficiency when angle θ1 is between zero degrees and fifteen degrees less than angle θ2. - In the embodiment of
FIG. 2 d,curved teeth curved edge 115 a andsurface 116 b ofcurved tooth 113 a leads the intersection ofcurved edge 115 b and surface 116 a ofcurved tooth 113 b in response torotating cutter body 101 indirection 107 a. In this way, the intersection ofcurved edge 115 a andsurface 116 b ofcurved tooth 113 a impacts the formation before the intersection ofcurved edge 115 b and surface 116 a ofcurved tooth 113 b in response torotating cutter body 101 indirection 107 a. Further,curved edge portion 117 a impacts the formation beforecurved edge portion 117 b, andcurved surface portion 118 a impacts the formation beforecurved surface portion 118 b. -
Cutter 110 provides many advantages. For example, the curved teeth ofcutter 110 overlap each other so thatcutter 110 is more stable in response tocutter body 101 rotating indirection 107 a.Cutter 110 is more stable in response tocutter body 101 rotating indirection 107 a because at least one curved tooth ofcutter 110 will always be in contact with the formation. In this way, the curved teeth will holdcutter body 101 to the formation so that it vibrates less. Further, the curved teeth ofcutter 110 will remain in contact with the formation for a longer amount of time than a straight tooth, such astooth 103. The curved teeth ofcutter 110 will remain in contact with the formation for a longer amount of time than a straight tooth because a curved tooth is generally longer than a straight tooth. Also, a curved tooth is longer than a straight tooth so that its number of impacts per revolution ofcutter body 101 is reduced. For example, a single curved tooth will experience one impact per revolution, but a straight tooth may experience multiple impacts per revolution. - Another advantage provided by
cutter 110 is that the curved teeth are not torqued upwardly in response to engaging the formation. It is known that straight teeth will be lifted up in response to engaging the formation, which causes them to experience an upwardly directed force that torques them. It is undesirable to torque the teeth of a cutter in this manner because they can fracture and become detached fromcutter body 101. - Another advantage provided by
cutter 110 is thatcurved teeth 113 each have a wider base which is blended intocutter body 101 for additional strength. The base of a curved tooth also facilitates the removal of cuttings from between adjacent curved teeth and reduces the likelihood of pack-off. A cutting is a portion of the formation that has been cut by the cutter. Pack-off occurs when a portion of the cutting is cut from the formation and becomes lodged between adjacent teeth. Pack-off will result in an effectively shortened tooth which will reduce the penetration rate of the tooth into the formation. -
FIG. 3 a is a perspective view of acutter 120, in accordance with the invention, andFIGS. 3 b and 3 c are end and side views, respectively, ofcutter 120.Cutter 120 is similar tocutter 110 discussed above, and includescutter body 101 withcentral opening 102. However, in accordance with the invention,cutter 120 includes a notchedcurved tooth 123 which extends indirection 107 a between opposed ends 106 a and 106 b and along the outer periphery ofcutter body 101.Cutter 120 can include any number of notched curved teeth, but it includes thirteen notched curved teeth here for reasons discussed above. In some embodiments, the number of notched curved teeth ofcutter 120 is in a range between about seven and nineteen. It should be noted that all the teeth included withcutter 120 can be notched curved teeth, or one or more of the teeth included withcutter 120 can be notched curved teeth. In this embodiment,cutter 120 includes one tooth (i.e. tooth 113) that is unnotched, and several curved teeth that are notched. - In accordance with the invention, notched
curved tooth 123 includes first andsecond tooth portions second tooth portions tooth 123 is a notched tooth and is not an unnotched tooth liketeeth Teeth second tooth portions cutter body 101 in the same direction as notchedcurved tooth 123. Hence, first andsecond tooth portions direction 107 a because notchedcurved tooth 123 extends indirection 107 a. - In this embodiment, notched
curved tooth 123 includescurved face 114 and curved edge 115 (FIG. 3 b), whereincurved face 114 andcurved edge 115 curve between ends 106 a and 106 b. In this way, notchedcurved tooth 123 is a curved tooth with a curved face. Hence, notchedcurved tooth 123 is not a straight tooth with a flat face liketooth 103 discussed above. The curvature ofcurved face 114 andcurved edge 115 can be seen inFIGS. 3 a, 3 b and 3 c. It should be noted thatcurved face 114 andcurved edge 115 extend through first andsecond tooth portions tooth portions curved face 114 andcurved edge 115. - In this embodiment, unnotched
curved tooth 123 includes opposedsurfaces 116 a (FIG. 3 c) and 116 b (FIG. 3 d) positioned proximate to ends 106 a and 106 b, respectively.Curved face 114 andcurved edge 115 curve betweensurfaces tooth 123 is a curved tooth with a curved face. Incutter 120,surfaces surfaces cutter 120 are typically different from each other. For example, in one embodiment,surface 116 a is shaped like an equilateral triangle andsurface 116 b is not shaped like an equilateral triangle. In another embodiment,surface 116 a is shaped like an isosceles triangle andsurface 116 b is not shaped like an isosceles triangle. In one embodiment,surface 116 a is shaped like an equilateral triangle andsurface 116 b is shaped like an isosceles or scalene triangle. In another embodiment,surface 116 a is shaped like an isosceles triangle andsurface 116 b is shaped like an equilateral or scalene triangle. In this way, the shapes ofsurfaces cutter 120 are different from each other. It should be noted that, inFIGS. 3 c and 3 d, surfaces 116 a and 116 b are shaped like isosceles and scalene triangles, respectively. - The dimensions of
surfaces cutter 120 are typically different from each other. As mentioned above, the dimensions ofsurfaces surface 116 a has a smaller area thansurface 116 b. - It should be noted that
surfaces second tooth portions FIGS. 3 a, 3 c and 3 d,first tooth portion 126 includes asurface 116 c which is opposed to surface 116 a, andsecond tooth portion 127 includes asurface 116 d which is opposed to surface 116 b. Hence,first tooth portion 126 extends betweensurfaces second tooth portion 127 extends betweensurfaces surfaces Curved face 114 andcurved edge 115 offirst tooth portion 126 extend betweensurfaces curved face 114 andcurved edge 115 ofsecond tooth portion 127 extend betweensurfaces - It should be noted that, in this embodiment, surfaces 116 c and 116 d have different dimensions. The dimensions of
surfaces surfaces surface 116 c has a smaller area thansurface 116 d. In other embodiments, surfaces 116 c and 116 d have the same dimensions whereinsurfaces - It should also be noted that, in this embodiment, surfaces 116 c and 116 d can have the same or different shapes. The shapes of
surfaces surfaces - In
FIGS. 3 c and 3 d,radial lines center 108 ofcutter body 101, whereinradial lines Radial line 109 a extends so that it intersects the intersection ofcurved edge 115 and surface 116 a, andradial line 109 b extends so that it intersects the intersection ofcurved edge 115 andsurface 116 b.Radial line 109 a extends so that it bisectssurface 116 a (FIG. 3 c) because the shape and area ofsurface 116 a oftooth 123 is the same on opposed sides ofradial line 109 a.Radial line 109 b extends so that it does not bisectsurface 116 b (FIG. 3 d) because the shape and area ofsurface 116 b oftooth 123 is not the same on opposed sides ofradial line 109 b. Hence,surface 116 a is symmetrical withradial line 109 a andsurface 116 b is non-symmetrical withradial line 109 b. - In this embodiment, curved edge 115 (
FIG. 3 b) oftooth portions radial lines Curved edge 115 is curved so thatradial lines FIGS. 3 c and 3 d. Angle θ1 is nonzero so that the same radial line does not extend through the intersections ofcurved edge 115 andopposed surfaces cutter 100. - Angle θ1 can have many different angular values, such as those mentioned in more detail above with
cutter 110. In general, the amount of curvature oftooth 123 increases and decreases as the magnitude of angle θ1 increases and decreases, respectively. The amount of curvature ofcurved face 114 andcurved edge 115 increases and decreases as the magnitude of angle θ1 increases and decreases, respectively. Further, the amount of twist oftooth 123 increases and decreases as the magnitude of angle θ1 increases and decreases, respectively. As the amount of twist oftooth 123 increases and decreases, the amount of twist ofcurved face 114 andcurved edge 115 increases and decreases, respectively. In this way, the amount of curvature and twist oftooth 123 is adjustable in response to adjusting the magnitude of angle θ1. - The amount of curvature of first and
second tooth portions curved face 114 andcurved edge 115 of first andsecond tooth portions second tooth portions second tooth portions curved face 114 andcurved edge 115 increases and decreases, respectively. In this way, the amount of curvature and twist of first andsecond tooth portions - In general, the length of notched
curved tooth 123 increases and decreases as the magnitude of angle θ1 increases and decreases, respectively. The length of notchedcurved tooth 123 typically corresponds with the length ofcurved edge 115. The length of notchedcurved tooth 123 increases and decreases as the length ofcurved edge 115 increases and decreases, respectively. Hence, the length ofcurved edge 115 increases and decreases as the magnitude of angle θ1 increases and decreases, respectively. - It should be noted that the curvature of notched
curved tooth 123, for a constant angle θ1, typically increases and decreases as the length ofcurved edge 115 decreases and increases, respectively. Further, the curvature of notchedcurved tooth 123, for a constant length ofcurved edge 115, typically increases and decreases as angle θ1 increases and decreases, respectively. -
FIG. 3 e is a close-up end view ofcutter 120 looking towardsend 106 a, as inFIG. 3 b. In accordance with the invention, the curved teeth ofcutter 120 overlap each other. It should be noted that the notched and unnotched curved teeth ofcutter 120 generally overlap each other. The curved teeth ofcutter 120 can overlap each other in many different ways. As shown inFIG. 3 e,cutter 120 includes notchedcurved teeth curved tooth 123 b is positioned between notchedcurved teeth Curved teeth curved tooth 123 discussed above. -
Curved tooth 123 a includes first andsecond tooth portions curved face 114 a andcurved edge 115 a.Curved face 114 a andcurved edge 115 a extend throughtooth portions Curved tooth 123 b includes first andsecond tooth portions curved face 114 b andcurved edge 115 b.Curved face 114 b andcurved edge 115 b extend throughtooth portions Curved tooth 123 c includes first andsecond tooth portions 126 c and 127 c with a curved face 114 c andcurved edge 115 c. Curved face 114 c andcurved edge 115 c extend throughtooth portions 126 c and 127 c. -
Radial line 109 a extends betweencenter 108 ofcutter body 101 and the intersection ofsurface 116 a oftooth 123 b andcurved edge 115 b. Further,radial line 109 b extends betweencenter 108 ofcutter body 101 and the intersection ofsurface 116 b ofcurved tooth 123 b andcurved edge 115 b. Aradial line 109 c extends betweencenter 108 ofcutter body 101 and the intersection ofsurface 116 a oftooth 123 c andcurved edge 115 c. As mentioned above,radial lines radial lines radial lines radial line 109 b is proximate to end 106 b. - In accordance with the invention, notched
curved teeth curved teeth curved teeth curved edge portion 117 c ofcurved edge 115 c overlaps curvededge portion 117 b ofcurved edge 115 b.Curved edge portions radial lines curved teeth curved edges cutter 120 includes unnotched curved teeth which overlap each other. - Angle θ1 is greater than angle θ2 so that a
curved surface portion 118 c of curved surface 114 c overlapscurved surface portion 118 b ofcurved surface 114 b.Curved surface portions radial lines Curved surface portion 118 b is bounded betweenradial lines curved edge portion 117 b andsurface 116 b oftooth 123 b. Further,curved surface portion 118 c is bounded betweenradial lines curved edge portion 117 c andsurface 116 c of tooth 113 c. Hence,curved teeth curved surfaces 114 b and 114 c overlap each other. In this way,cutter 120 includes notched curved teeth which overlap each other. - The amount of overlap of
curved teeth curved surface 114 b oftooth portion 127 b. Further, the difference between angles θ1 and θ2 can be increased by increasing the curvature ofcurved edge 115 b oftooth portion 127 b. The difference between angles θ1 and θ2 can be decreased by decreasing the curvature ofcurved surface 114 b oftooth portion 127 b. Further, the difference between angles θ1 and θ2 can be decreased by decreasing the curvature ofcurved edge 115 b oftooth portion 127 b. In this way, the amount of overlap ofcurved teeth curved surface 114 b andcurved edge 115 b oftooth portion 127 b. - It should be noted that
curved teeth curved teeth cutter 120 provides an improved cutting efficiency whenteeth curved teeth cutter 120 provides an improved cutting efficiency when angle θ1 is between zero degrees and five degrees less than angle θ2. In some embodiments,cutter 120 provides an improved cutting efficiency when angle θ1 is between zero degrees and ten degrees less than angle θ2. In some embodiments,cutter 120 provides an improved cutting efficiency when angle θ1 is between zero degrees and fifteen degrees less than angle θ2. - In the embodiment of
FIG. 3 e,curved teeth curved edge 115 b andsurface 116 b ofcurved tooth 123 b leads the intersection ofcurved edge 115 c and surface 116 a ofcurved tooth 123 c in response torotating cutter body 101 indirection 107 a. In this way, the intersection ofcurved edge 115 b andsurface 116 b ofcurved tooth 123 b impacts the formation before the intersection ofcurved edge 115 c and surface 116 a ofcurved tooth 123 c in response torotating cutter body 101 indirection 107 a. -
FIG. 3 f is a close-up side view ofcutter 120, as seen inFIG. 3 b. In accordance with the invention, the notches of each adjacent notched curved tooth are offset from each other. The notches of each adjacent notched curved tooth can be offset from each other in many different ways. For example, the notches of each adjacent curved tooth can be staggered relative to each other. When the notches of adjacent curved teeth are staggered relative to each other, they are a different distance away fromend 106 a. Further, when the notches of adjacent curved teeth are staggered relative to each other, they are a different distance fromend 106 b. - For example, in this embodiment,
cutter 120 includes notchedcurved teeth curved tooth 123 c is positioned between notchedcurved teeth curved teeth notches Notches end 106 b, wherein distance D1 is less than distance D2 and distance D2 is less than distance D3. In this way,notches end 106 b so that they are staggered relative to each other. - It should be noted that distances D1, D2 and D3 can correspond to many different distances between
end 106 b andcorresponding notches end 106 b and the intersection ofsurface 116 d andcurved edge 115 a oftooth portion 127 a oftooth 123 a. Distance D2 is the distance betweenend 106 b and the intersection ofsurface 116 d andcurved edge 115 b oftooth portion 127 b oftooth 123 b. Further, distance D3 is the distance betweenend 106 b and the intersection ofsurface 116 d andcurved edge 115 c oftooth portion 127 c oftooth 123 c. It should be noted that three different notch positions for the staggered notches are shown in this example for illustrative purposes. However,cutter 120 generally includes two or more different notch positions for the staggered notches. -
Cutter 120 provides many advantages, such as those mentioned above withcutter 110. For example, the curved teeth ofcutter 120 overlap each other so thatcutter 120 is more stable in response tocutter body 101 rotating indirection 107 a. Another advantage provided bycutter 120 is that the notches allow material from the cuttings to flow therethrough, which reduces the likelihood of pack-off and increases the drilling efficiency. In general, the drilling efficiency increases whencutter 120 cuts through more material per rotation. Further, the notches are staggered relative to each other, which facilitates the removal of material from between adjacent teeth and reduces the amount of pack-off. -
FIG. 4 a is a perspective view of acutter 130, in accordance with the invention, andFIGS. 4 b and 4 c are end and side views, respectively, ofcutter 130.Cutter 130 is similar tocutters cutter body 101 withcentral opening 102. However, in accordance with the invention,cutter 130 includes a notchedcurved tooth 133 which extends in adirection 107 b between opposed ends 106 a and 106 b and along the outer periphery ofcutter body 101.Direction 107 b is opposed todirection 107 a. Hence,direction 107 b is clockwise ifdirection 107 a is counterclockwise, anddirection 107 b is counterclockwise ifdirection 107 a is clockwise. -
Cutter 130 can include any number of notched curved teeth, but it includes thirteen notched curved teeth here for reasons discussed above. In some embodiments, the number of notched curved teeth ofcutter 130 is in a range between about seven and nineteen. It should be noted that all the teeth included withcutter 130 can be notched curved teeth, or one or more of the teeth included withcutter 130 can be notched curved teeth. In this embodiment,cutter 130 includes one tooth (i.e. tooth 113) that is unnotched, and several curved teeth that are notched. - In accordance with the invention, notched
curved tooth 133 includes first andsecond tooth portions notch 138 positioned between them. In this way, first andsecond tooth portions notch 138. Hence,tooth 133 is a notched tooth and is not an unnotched tooth liketeeth Teeth second tooth portions notch 138, extend aroundcutter body 101 in the same direction as notchedcurved tooth 133. Hence, first andsecond tooth portions direction 107 b because notchedcurved tooth 133 extends indirection 107 b. - In this embodiment, notched
curved tooth 133 includescurved face 114 and curved edge 115 (FIG. 4 b), whereincurved face 114 andcurved edge 115 curve between ends 106 a and 106 b. In this way, notchedcurved tooth 133 is a curved tooth with a curved face. Hence, notchedcurved tooth 133 is not a straight tooth with a flat face, liketooth 103 discussed above. The curvature ofcurved face 114 andcurved edge 115 can be seen inFIGS. 4 a, 4 b and 4 c. It should be noted thatcurved face 114 andcurved edge 115 extend through first andsecond tooth portions tooth portions curved face 114 andcurved edge 115. - In this embodiment, unnotched
curved tooth 133 includes opposedsurfaces 116 a (FIG. 4 c) and 116 b (FIG. 4 d) positioned proximate to ends 106 a and 106 b, respectively.Curved face 114 andcurved edge 115 curve betweensurfaces tooth 133 is a curved tooth with a curved face. Incutter 130,surfaces surfaces cutter 130 are typically different from each other. For example, in one embodiment,surface 116 a is shaped like an equilateral triangle andsurface 116 b is not shaped like an equilateral triangle. In another embodiment,surface 116 a is shaped like an isosceles triangle andsurface 116 b is not shaped like an isosceles triangle. In one embodiment,surface 116 a is shaped like an equilateral triangle andsurface 116 b is shaped like an isosceles or scalene triangle. In another embodiment,surface 116 a is shaped like an isosceles triangle andsurface 116 b is shaped like an equilateral or scalene triangle. In this way, the shapes ofsurfaces cutter 130 are different from each other. It should be noted that, inFIGS. 4 c and 4 d, surfaces 116 a and 116 b are shaped like isosceles and scalene triangles, respectively. - The dimensions of
surfaces cutter 130 are typically different from each other. As mentioned above, the dimensions ofsurfaces surface 116 a has a smaller area thansurface 116 b. - It should be noted that
surfaces second tooth portions FIGS. 4 a, 4 c and 4 d, first tooth portion 146 includessurface 116 c which is opposed to surface 116 a, andsecond tooth portion 137 includessurface 116 d which is opposed to surface 116 b. Hence,first tooth portion 136 extends betweensurfaces second tooth portion 137 extends betweensurfaces notch 138 extends betweensurfaces Curved face 114 andcurved edge 115 offirst tooth portion 136 extend betweensurfaces curved face 114 andcurved edge 115 ofsecond tooth portion 137 extend betweensurfaces - It should be noted that, in this embodiment, surfaces 116 c and 116 d have different dimensions. The dimensions of
surfaces surfaces surface 116 c has a smaller area thansurface 116 d. In other embodiments, surfaces 116 c and 116 d have the same dimensions whereinsurfaces - It should also be noted that, in this embodiment, surfaces 116 c and 116 d can have the same or different shapes. The shapes of
surfaces surfaces - In
FIGS. 4 c and 4 d,radial lines center 108 ofcutter body 101, whereinradial lines Radial line 109 a extends so that it intersects the intersection ofcurved edge 115 and surface 116 a, andradial line 109 b extends so that it intersects the intersection ofcurved edge 115 andsurface 116 b.Radial line 109 a extends so that it bisectssurface 116 a (FIG. 4 c) because the shape and area ofsurface 116 a oftooth 123 is the same on opposed sides ofradial line 109 a.Radial line 109 b extends so that it does not bisectsurface 116 b (FIG. 4 d) because the shape and area ofsurface 116 b oftooth 123 is not the same on opposed sides ofradial line 109 b. Hence,surface 116 a is symmetrical withradial line 109 a andsurface 116 b is non-symmetrical withradial line 109 b. - In this embodiment, curved edge 115 (
FIG. 4 b) oftooth portions radial lines Curved edge 115 is curved so thatradial lines FIGS. 4 c and 4 d. Angle θ1 is nonzero so that the same radial line does not extend through the intersections ofcurved edge 115 andopposed surfaces cutter 100. Angle θ1 can have many different angular values. In general, the amount of curvature oftooth 133 increases and decreases as the magnitude of angle θ1 increases and decreases, respectively. The amount of curvature ofcurved face 114 andcurved edge 115 increases and decreases as the magnitude of angle θ1 increases and decreases, respectively. Further, the amount of twist oftooth 133 increases and decreases as the magnitude of angle θ1 increases and decreases, respectively. As the amount of twist oftooth 133 increases and decreases, the amount of twist ofcurved face 114 andcurved edge 115 increases and decreases, respectively. In this way, the amount of curvature and twist oftooth 133 is adjustable in response to adjusting the magnitude of angle θ1. - The amount of curvature of first and
second tooth portions curved face 114 andcurved edge 115 of first andsecond tooth portions second tooth portions second tooth portions curved face 114 andcurved edge 115 increases and decreases, respectively. In this way, the amount of curvature and twist of first andsecond tooth portions - In general, the length of notched
curved tooth 133 increases and decreases as the magnitude of angle θ1 increases and decreases, respectively. The length of notchedcurved tooth 133 typically corresponds with the length ofcurved edge 115. The length of notchedcurved tooth 133 increases and decreases as the length ofcurved edge 115 increases and decreases, respectively. Hence, the length ofcurved edge 115 increases and decreases as the magnitude of angle θ1 increases and decreases, respectively. - It should be noted that the curvature of notched
curved tooth 133, for a constant angle θ1, typically increases and decreases as the length ofcurved edge 115 decreases and increases, respectively. Further, the curvature of notchedcurved tooth 133, for a constant length ofcurved edge 115, typically increases and decreases as angle θ1 increases and decreases, respectively. -
FIG. 4 e is a close-up end view ofcutter 130 looking towardsend 106 a, as inFIG. 4 b. In accordance with the invention, the curved teeth ofcutter 130 overlap each other. It should be noted that the notched and unnotched curved teeth ofcutter 130 generally overlap each other. The curved teeth ofcutter 130 can overlap each other in many different ways. As shown inFIG. 4 e,cutter 130 includes notchedcurved teeth Curved teeth curved tooth 133 discussed above. -
Curved tooth 133 a includes first andsecond tooth portions curved face 114 a andcurved edge 115 a.Curved face 114 a andcurved edge 115 a extend throughtooth portions Curved tooth 133 b includes first andsecond tooth portions curved face 114 b andcurved edge 115 b.Curved face 114 b andcurved edge 115 b extend throughtooth portions -
Radial line 109 a extends betweencenter 108 ofcutter body 101 and the intersection ofsurface 116 a oftooth 133 a andcurved edge 115 a. Further,radial line 109 b extends betweencenter 108 ofcutter body 101 and the intersection ofsurface 116 b ofcurved tooth 133 a andcurved edge 115 a.Radial line 109 c extends betweencenter 108 ofcutter body 101 and the intersection ofsurface 116 a oftooth 133 b andcurved edge 115 b. As mentioned above,radial lines radial lines radial lines radial line 109 b is proximate to end 106 b. - In accordance with the invention, notched
curved teeth curved teeth curved teeth curved edge portion 117 b ofcurved edge 115 b overlaps acurved edge portion 117 a ofcurved edge 115 a.Curved edge portions radial lines curved teeth curved edges cutter 130 includes unnotched curved teeth which overlap each other. - Angle θ1 is greater than angle θ2 so that
curved surface portion 118 b ofcurved surface 114 b overlapscurved surface portion 118 a ofcurved surface 114 a.Curved surface portions radial lines Curved surface portion 118 a is bounded betweenradial lines curved edge portion 117 a andsurface 116 b oftooth 133 a. Further,curved surface portion 118 b is bounded betweenradial lines curved edge portion 117 b and surface 116 a oftooth 113 b. Hence,curved teeth curved surfaces cutter 130 includes notched curved teeth which overlap each other. - The amount of overlap of
curved teeth curved surface 114 a oftooth portion 137 a. Further, the difference between angles θ1 and θ2 can be increased by increasing the curvature ofcurved edge 115 a oftooth portion 137 a. The difference between angles θ1 and θ2 can be decreased by decreasing the curvature ofcurved surface 114 a oftooth portion 137 a. Further, the difference between angles θ1 and θ2 can be decreased by decreasing the curvature ofcurved edge 115 a oftooth portion 137 a. In this way, the amount of overlap ofcurved teeth curved surface 114 a andcurved edge 115 a oftooth portion 137 a. - It should be noted that
curved teeth curved teeth cutter 130 provides an improved cutting efficiency whenteeth curved teeth cutter 130 provides an improved cutting efficiency when angle θ1 is between zero degrees and five degrees less than angle θ2. In some embodiments,cutter 130 provides an improved cutting efficiency when angle θ1 is between zero degrees and ten degrees less than angle θ2. In some embodiments,cutter 130 provides an improved cutting efficiency when angle θ1 is between zero degrees and fifteen degrees less than angle θ2. - In the embodiment of
FIG. 4 e,curved teeth curved edge 115 a andsurface 116 b ofcurved tooth 133 a leads the intersection ofcurved edge 115 b and surface 116 a ofcurved tooth 133 b in response torotating cutter body 101 indirection 107 b. In this way, the intersection ofcurved edge 115 a andsurface 116 b ofcurved tooth 133 a impacts the formation before the intersection ofcurved edge 115 b and surface 116 a ofcurved tooth 133 b in response torotating cutter body 101 indirection 107 b. -
FIG. 4 f is a close-up side view ofcutter 130, as seen inFIG. 4 b. In accordance with the invention, the notches of each adjacent notched curved tooth are offset from each other. The notches of each adjacent notched curved tooth can be offset from each other in many different ways. For example, the notches of each adjacent curved tooth can be staggered relative to each other. When the notches of adjacent curved teeth are staggered relative to each other, they are a different distance away fromend 106 a. Further, when the notches of adjacent curved teeth are staggered relative to each other, they are a different distance fromend 106 b. - For example, in this embodiment,
cutter 130 includes notchedcurved teeth curved tooth 133 c is positioned between notchedcurved teeth curved teeth notches Notches end 106 b, wherein distance D1 is less than distance D2 and distance D2 is less than distance D3. In this way,notches end 106 b so that they are staggered relative to each other. - It should be noted that distances D1, D2 and D3 can correspond to many different distances between
end 106 b andcorresponding notches end 106 b and the intersection ofsurface 116 d andcurved edge 115 a oftooth portion 137 a oftooth 133 a. Distance D2 is the distance betweenend 106 b and the intersection ofsurface 116 d andcurved edge 115 b oftooth portion 137 b oftooth 133 b. Further, distance D3 is the distance betweenend 106 b and the intersection ofsurface 116 d andcurved edge 115 c oftooth portion 137 c oftooth 133 c. It should be noted that three different notch positions for the staggered notches are shown in this example for illustrative purposes. However,cutter 130 generally includes two or more different notch positions for the staggered notches. -
Cutter 130 provides many advantages, such as those mentioned above withcutters cutter 130 overlap each other so thatcutter 130 is more stable in response tocutter body 101 rotating indirection 107 a. Another advantage provided bycutter 130 is that the notches allow material from the cuttings to flow therethrough, which reduces the likelihood of pack-off and increases the drilling efficiency. Further, the notches are staggered relative to each other, which facilitates the removal of material from between adjacent teeth and reduces the amount of pack-off. Another advantage provided bycutter 120 is that the notches allow material from the cuttings to flow therethrough, which reduces the likelihood of pack-off -
FIGS. 5 a and 5 b are bottom perspective and bottom views, respectively, of anearth bit 150, in accordance with the invention, which can carry the cutters discussed above. In this embodiment,earth bit 150 is embodied as a rolling cutter earth bit and includes anearth bit body 151 which carries saddles 152, 153, 154, 155 and 156.Earth bit 150 includescutters cutter 120 is rotatably mounted tosaddles cutter 130 is rotatably mounted tosaddles Cutters Saddles FIG. 5 b) ofearth bit body 151. The longitudinal axis ofsaddle 152 is indicated inFIGS. 5 a and 5 b and denoted asaxis 169, whereinaxis 169 extends throughcenter 158. It should be noted that the cutter rotatably mounted to saddle 152 rotates aboutaxis 169. - The amount of tracking experienced by the cutters of an earth bit is typically reduced by including cutters having different numbers of teeth. However, in accordance with the invention, the cutters of
earth bit 150 experience less tracking, even when they have the same number of teeth. The cutters ofearth bit 150 can experience less tracking even when they have the same number of teeth in many different ways. - In accordance with the invention, the saddles of
earth bit 150 are positioned relative to each other to reduce the amount of tracking experienced by the teeth of the cutters ofearth bit 150. The saddles ofearth bit 150 can be positioned relative to each other in many different ways to reduce the amount of tracking experienced by the teeth of the cutters ofearth bit 150. As best seen inFIG. 5 b, the saddles are offset so that they are positioned at various distances fromcenter 158 ofearth bit body 151. - For example, in this embodiment, saddles 153 and 155 are positioned closer to
center 158 thansaddles saddles center 158, wherein the radial distance corresponds with the radius of areference circle 157. Further, saddles 152, 154 and 156 are positioned a radial distance fromcenter 158, wherein the radial distance corresponds with the radius of areference circle 159. The radius ofreference circle 157 is less than the radius ofreference circle 159 so that saddles 153 and 155 are closer to center 158 thansaddles center 158 thansaddles reference circle 157 is less than the radius ofreference circle 159 so that the cutters rotatably mounted to saddles 153 and 155 are closer to center 158 than the cutters rotatably mounted tosaddles center 158 than the cutters rotatably mounted tosaddles - In accordance with the invention, the types of cutters rotatably mounted in the saddles of
earth bit 150 are selected to reduce the amount of tracking experienced by their teeth. The types of cutters rotatably mounted in the saddles ofearth bit 150 can be selected in many different ways to reduce the amount of tracking experienced by their teeth. In this embodiment,saddle 153 is positioned betweensaddles cutter 130 is rotatably mounted withsaddles cutter 120 is rotatably mounted withsaddle 153. In this way,cutter 120 is positioned between twocutters 130.Cutter 120 includes teeth that curve indirection 107 a andcutter 130 includes teeth that curve indirection 107 b. Hence, the amount of tracking experienced by the teeth of the cutters rotatably mounted tosaddles direction 107 a) between two cutters with teeth curving in an opposed direction (i.e.direction 107 b). It should be noted that the amount of tracking experienced by the two cutters is reduced even when they both include the same or a different number of teeth. - In some embodiments,
cutter 130 is rotatably mounted to saddle 153 andcutter 130 is rotatably mounted tosaddles saddles direction 107 b) between two cutters with teeth curving in an opposed direction (i.e.direction 107 a). - Hence, in accordance with the invention,
cutters earth bit 150 can each have the same number of teeth and still experience less tracking. In this particular embodiment,cutters earth bit 150 each have thirteen teeth. However, as mentioned above,cutters cutters cutter 120 includes eleven teeth ifcutter 130 includes eleven teeth andcutter 120 includes fourteen teeth ifcutter 130 includes fourteen teeth. - It should be noted that the cutters of
earth bit 150 are interchangeable and replaceable with the cutters discussed herein. Hence, any ofcutters saddles earth bit 150 depends on many different factors, such as the hardness of the formation it is desired to bore through. For example,cutter 100 and/orcutter 110 are typically selected when it is desired to bore through a hard or medium hard formation. Further,cutter 120 and/orcutter 130 are typically selected when it is desired to bore through a soft formation. In this way, the cutters ofearth bit 100 are interchangeable and can be chosen in response to the type of formation it is desired to bore through. -
FIGS. 6 a and 6 b are bottom perspective and bottom views, respectively, of anearth bit 160, in accordance with the invention, which can carry the cutters discussed above. In this embodiment,earth bit 160 is embodied as a rolling cutter earth bit and includesearth bit body 151 which carries saddles 152, 153, 154, 155 and 156, which are discussed above.Earth bit 160 includescutters cutter 120 is rotatably mounted tosaddles cutter 130 is rotatably mounted tosaddles Cutters Saddles FIG. 6 b) ofearth bit body 151. The longitudinal axis ofsaddle 152 is indicated inFIGS. 6 a and 6 b and denoted asaxis 169, whereinaxis 169 extends throughcenter 158. It should be noted that the cutter rotatably mounted to saddle 152 rotates aboutaxis 169. - As mentioned above, the amount of tracking experienced by the cutters of an earth bit is typically reduced by including cutters having different numbers of teeth. However, in accordance with the invention, the cutters of
earth bit 160 experience less tracking, even when they have the same number of teeth. The cutters ofearth bit 160 can experience less tracking even when they have the same number of teeth in many different ways, such as those discussed above withearth bit 150. - In accordance with the invention, the saddles of
earth bit 160 are positioned relative to each other to reduce the amount of tracking experienced by the teeth of the cutters ofearth bit 150. The saddles ofearth bit 160 can be positioned relative to each other in many different ways to reduce the amount of tracking experienced by the teeth of the cutters ofearth bit 160. As best seen inFIG. 6 b, the saddles are offset so that they are positioned at various distances fromcenter 158 ofearth bit body 151. More information about offsetting saddles of an earth bit is provided above withFIGS. 5 a and 5 b. - In this embodiment, the amount of tracking experienced by the teeth of the cutters of
earth bit 100 is reduced by includes a cuttingcone 161 rotatably mounted to alug 162, whereinlug 162 is carried byearth bit body 151.Lug 162 and cuttingcone 161 are positioned betweensaddles cutters saddles lug 162 and cuttingcone 161 are positioned betweencutters cutters saddles - While particular embodiments of the invention have been shown and described, numerous variations and alternate embodiments will occur to those skilled in the art. Accordingly, it is intended that the invention be limited only in terms of the appended claims.
Claims (20)
1. A cutter, comprising:
a cutter body having opposed openings; and
a plurality of curved teeth extending around the outer periphery of the cutter body and between opposed ends, wherein the curved teeth have a curved edge, and a curved leading face that curves as it extends between opposed ends of the cutter body.
2. The cutter of claim 1 , wherein the curved teeth are positioned so that an end of a curved tooth overlaps an opposed end of an adjacent curved tooth.
3. The cutter of claim 1 , wherein opposed ends of each curved tooth have different dimensions.
4. The cutter of claim 1 , wherein the plurality of curved teeth includes at least one curved tooth having first and second tooth portions spaced apart from each other.
5. The cutter of claim 1 , wherein the plurality of curved teeth includes first and second notched curved teeth.
6. The cutter of claim 5 , wherein the notches of the first and second notched curved teeth are offset from each other.
7. The cutter of claim 5 , wherein the plurality of curved teeth includes an unnotched curved tooth.
8. An earth bit, comprising:
an earth bit body; and
a first cutter rotatably mounted to the earth bit body with a first saddle, the first cutter including a cutter body and a first plurality of curved teeth extending in a direction around the outer periphery of the cutter body and between opposed ends, the curved teeth being positioned so that one end of a curved tooth overlaps an opposed end of an adjacent curved tooth.
9. The cutter of claim 8 , wherein the dimensions of a curved tooth at its end surface are smaller than the dimensions of the curved tooth at its opposed end surface.
10. The cutter of claim 8 , wherein the curved teeth include a curved edge, and a curved face that curves as it extends away from the curved edge.
11. The cutter of claim 8 , wherein the first plurality of curved teeth includes at least one curved tooth having first and second tooth portions spaced apart from each other.
12. The earth bit of claim 8 , further including a second cutter rotatably mounted to the earth bit body with a second saddle, the second cutter including
a cutter body; and
a second plurality of curved teeth extending between opposed ends and in an opposed direction around the outer periphery of the cutter body, the curved teeth being positioned so that one end of a curved tooth overlaps the opposed end of an adjacent curved tooth.
13. The earth bit of claim 12 , wherein the number of curved teeth of the first and second cutters are the same.
14. The earth bit of claim 12 , wherein the first and second saddles are offset from each other.
15. The earth bit of claim 12 , further including a third cutter rotatably mounted to the earth bit body with a third saddle, the third cutter including
a cutter body; and
a third plurality of curved teeth extending between opposed ends and in the direction around the outer periphery of the cutter body, the curved teeth being positioned so that one end of a curved tooth overlaps the opposed end of an adjacent curved tooth;
wherein the second cutter is positioned between the first and third cutters.
16. An earth bit, comprising:
an earth bit body;
a lug and cutting cone carried by the earth bit body, the cutting cone being rotatably mounted to the lug; and
a plurality of cutters carried by the earth bit body, wherein the cutters include a cutter body and a plurality of curved teeth extending between opposed ends of the cutter body, the curved teeth being positioned so that one end of a tooth overlaps an opposed end of an adjacent tooth;
wherein the curved teeth of a first cutter extend in a direction around its corresponding cutter body and the curved teeth of a second cutter extend in an opposed direction around its corresponding cutter body.
17. The earth bit of claim 16 , wherein a tooth of the first cutter includes first and second tooth portions spaced apart from each other.
18. The cutter of claim 16 , wherein the dimensions of a curved tooth of the first cutter at its opposed end surfaces are different from each other.
19. The cutter of claim 16 , further including a third cutter having teeth which extend in the same direction as the teeth of the first cutter, the second cutter being positioned between the first and third cutters.
20. The cutter of claim 19 , wherein the second cutter is offset from the first and third cutters.
Priority Applications (6)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US12/189,011 US20100032216A1 (en) | 2008-08-08 | 2008-08-08 | Earth boring cutter employing helical teeth |
PCT/US2009/053119 WO2010017460A1 (en) | 2008-08-08 | 2009-08-07 | Earth boring cutter employing helical teeth |
CA2733563A CA2733563A1 (en) | 2008-08-08 | 2009-08-07 | Earth boring cutter employing helical teeth |
AU2009279463A AU2009279463A1 (en) | 2008-08-08 | 2009-08-07 | Earth boring cutter employing helical teeth |
MX2011001538A MX2011001538A (en) | 2008-08-08 | 2009-08-07 | Earth boring cutter employing helical teeth. |
BRPI0917134A BRPI0917134A2 (en) | 2008-08-08 | 2009-08-07 | cutter and soil drill. |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US12/189,011 US20100032216A1 (en) | 2008-08-08 | 2008-08-08 | Earth boring cutter employing helical teeth |
Publications (1)
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US20100032216A1 true US20100032216A1 (en) | 2010-02-11 |
Family
ID=41212185
Family Applications (1)
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US12/189,011 Abandoned US20100032216A1 (en) | 2008-08-08 | 2008-08-08 | Earth boring cutter employing helical teeth |
Country Status (6)
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US (1) | US20100032216A1 (en) |
AU (1) | AU2009279463A1 (en) |
BR (1) | BRPI0917134A2 (en) |
CA (1) | CA2733563A1 (en) |
MX (1) | MX2011001538A (en) |
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Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US11607737B2 (en) * | 2019-09-16 | 2023-03-21 | Guehring Kg | Milling tool |
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US839837A (en) * | 1906-04-02 | 1907-01-01 | Taylor Iron & Steel Company | Drill-bit for wells. |
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US4167980A (en) * | 1978-04-12 | 1979-09-18 | Dresser Industries, Inc. | Rock boring cutter with replaceable cutting element |
US4320808A (en) * | 1980-06-24 | 1982-03-23 | Garrett Wylie P | Rotary drill bit |
US4359114A (en) * | 1980-12-10 | 1982-11-16 | Robbins Machine, Inc. | Raise drill bit inboard cutter assembly |
US4393949A (en) * | 1980-12-29 | 1983-07-19 | Peterson Associates, Ltd. | Rock boring apparatus |
US5456328A (en) * | 1994-01-07 | 1995-10-10 | Dresser Industries, Inc. | Drill bit with improved rolling cutter tooth pattern |
US7059431B2 (en) * | 2000-03-01 | 2006-06-13 | Armines | Self-penetrating drilling method and thrust-generating tool for implementing same |
US20080149396A1 (en) * | 2005-01-27 | 2008-06-26 | George Fyfe | Roller Reamer |
-
2008
- 2008-08-08 US US12/189,011 patent/US20100032216A1/en not_active Abandoned
-
2009
- 2009-08-07 AU AU2009279463A patent/AU2009279463A1/en not_active Abandoned
- 2009-08-07 MX MX2011001538A patent/MX2011001538A/en unknown
- 2009-08-07 CA CA2733563A patent/CA2733563A1/en not_active Abandoned
- 2009-08-07 BR BRPI0917134A patent/BRPI0917134A2/en not_active IP Right Cessation
- 2009-08-07 WO PCT/US2009/053119 patent/WO2010017460A1/en active Application Filing
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USRE19339E (en) * | 1934-10-09 | Well reamer | ||
US839837A (en) * | 1906-04-02 | 1907-01-01 | Taylor Iron & Steel Company | Drill-bit for wells. |
US1010143A (en) * | 1909-03-11 | 1911-11-28 | Howard R Hughes | Roller-drill. |
US1238407A (en) * | 1916-11-01 | 1917-08-28 | Hughes Tool Co | Rotary boring-drill. |
US1494274A (en) * | 1921-08-02 | 1924-05-13 | James G Morgan | Expansion coal cutter |
US1816549A (en) * | 1928-08-30 | 1931-07-28 | Starkey William Carleton | Drill for wells |
US1885085A (en) * | 1930-11-26 | 1932-10-25 | William F Dalzen | Rock drill |
US2025260A (en) * | 1934-10-26 | 1935-12-24 | John A Zublin | Cutter for drill bits |
US2177332A (en) * | 1937-10-01 | 1939-10-24 | Chicago Pneumatic Tool Co | Roller cutter organization for earth boring drills |
US2230569A (en) * | 1939-12-20 | 1941-02-04 | Globe Oil Tools Co | Roller cutter |
US2528300A (en) * | 1945-06-30 | 1950-10-31 | Charles F Degner | Cutting implement |
US2634955A (en) * | 1950-05-15 | 1953-04-14 | Jeners S Johnson | Rotary drill |
US2663546A (en) * | 1951-02-09 | 1953-12-22 | Archer W Kammerer | Rotary drill bit and cutter |
US2886293A (en) * | 1955-01-10 | 1959-05-12 | Charles J Carr | Directional well bore roller bit |
US3401759A (en) * | 1966-10-12 | 1968-09-17 | Hughes Tool Co | Heel pack rock bit |
US3444939A (en) * | 1967-12-11 | 1969-05-20 | Karl Gunther Bechem | Cutting roller in particular roller-type enlarging bits |
US3775819A (en) * | 1972-12-14 | 1973-12-04 | Weldon Tool Co | Rotating cutting tool |
US4106578A (en) * | 1976-05-04 | 1978-08-15 | Leaman Rex Beyer | Percussion drill bit |
US4040493A (en) * | 1976-05-13 | 1977-08-09 | Dresser Industries, Inc. | Rock boring cutter with thread-on replaceable cutting element |
US4161225A (en) * | 1977-12-07 | 1979-07-17 | Dresser Industries, Inc. | Skewed inserts for an earth boring cutter |
US4167980A (en) * | 1978-04-12 | 1979-09-18 | Dresser Industries, Inc. | Rock boring cutter with replaceable cutting element |
US4320808A (en) * | 1980-06-24 | 1982-03-23 | Garrett Wylie P | Rotary drill bit |
US4359114A (en) * | 1980-12-10 | 1982-11-16 | Robbins Machine, Inc. | Raise drill bit inboard cutter assembly |
US4393949A (en) * | 1980-12-29 | 1983-07-19 | Peterson Associates, Ltd. | Rock boring apparatus |
US5456328A (en) * | 1994-01-07 | 1995-10-10 | Dresser Industries, Inc. | Drill bit with improved rolling cutter tooth pattern |
US7059431B2 (en) * | 2000-03-01 | 2006-06-13 | Armines | Self-penetrating drilling method and thrust-generating tool for implementing same |
US20080149396A1 (en) * | 2005-01-27 | 2008-06-26 | George Fyfe | Roller Reamer |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US11607737B2 (en) * | 2019-09-16 | 2023-03-21 | Guehring Kg | Milling tool |
Also Published As
Publication number | Publication date |
---|---|
AU2009279463A1 (en) | 2010-02-11 |
CA2733563A1 (en) | 2010-02-11 |
BRPI0917134A2 (en) | 2015-11-10 |
MX2011001538A (en) | 2011-05-02 |
WO2010017460A1 (en) | 2010-02-11 |
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Legal Events
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Owner name: ATLAS COPCO SECOROC LLC,TEXAS Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:OSBORNE, ANDREW J., JR.;REEL/FRAME:023077/0019 Effective date: 20090803 |
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STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |