Abstract: A hybrid drill bit having at least two rolling cutters, each rotatable around an axis of rotation, at least one of the rolling cutters having a high pin angle, and at least one fixed blade. The pin angle can encompass pin angles above 39 degrees to less than 393 degrees. The drill bit can allow the rolling cutters to engage a shoulder portion and/or gage portion of the bit profile and assist the fixed blade(s) in these areas. The at least two rolling cutters can be disposed at different pin angles.

Abstract: A rock drilling bit having PDC radial bearings has journal and cone bearing surfaces with increased contact area to increase load support. The radius of curvature of the bearing pin journal and cone bearing surfaces are matched or conformed on the bearing pressure side. The conformal journal surfaces may be formed on the main journal bearing, the pilot pin radial bearing, or both surfaces. In addition, diamond inlays may be located on the bearing surfaces of the cone, the bearing pin, or both components.

Abstract: An apparatus for retaining a roller cone on a bearing pin of a drill bit body that includes a drill bit body; a bearing pin coupled to the drill bit body; a retention member coupled to the bearing pin; a roller cone coupled to the retention member; and a torque transfer member coupled to the retention member and the roller cone adapted to selectively transfer torque between the retention member and the roller cone.

Abstract: An earth-boring bit comprising a bit body is configured at its upper end for connection into a drillstring. A fixed blade depends axially downwardly from the bit body. An axially extending slot is formed in the bit body adjacent the fixed blade. A bit leg is received and retained in the slot by engagement between the slot and correspondingly shaped bit leg, wherein the bit leg cannot be removed from the slot except by axial movement relative to the bit body. A rolling cutter is secured to the bit leg at its lower extent. A fastener secures the bit leg against movement relative to the bit body and extends through oblong apertures in the bit leg and into the bit body, wherein the bit leg can be moved axially relative to the bit body to adjust the projection of the rolling cutter relative to the fixed blade.

Abstract: A rock drilling bit having PDC radial bearings has journal and cone bearing surfaces with increased contact area to increase load support. The radius of curvature of the bearing pin journal and cone bearing surfaces are matched or conformed on the bearing pressure side. The conformal journal surfaces may be formed on the main journal bearing, the pilot pin radial bearing, or both surfaces. In addition, diamond inlays may be located on the bearing surfaces of the cone, the bearing pin, or both components.

Abstract: An earth boring bit formed from an alloy comprising a low carbon content and high molybdenum content is disclosed herein. The molybdenum content is greater than about 0.8% to about 1.15% by weight of the alloy. The carbon content may range up to about 0.16% by weight of the alloy. The alloy may further comprise alloy further comprises manganese, phosphorus, sulfur, silicon, nickel, chromium, copper, aluminum, vanadium, and calcium; with the balance being iron. The alloy experiences a relatively flattened hardenability curve and low martinsite formation.

Abstract: A rock drilling bit having PDC radial bearings has journal and cone bearing surfaces with increased contact area to increase load support. The radius of curvature of the bearing pin journal and cone bearing surfaces are matched or conformed on the bearing pressure side. The conformal journal surfaces may be formed on the main journal bearing, the pilot pin radial bearing, or both surfaces. In addition, diamond inlays may be located on the bearing surfaces of the cone, the bearing pin, or both components.

Abstract: A hybrid drill bit having both roller cones and fixed blades is disclosed, and a method of drilling. The cutting elements on the fixed blades form a continuous cutting profile from the perimeter of the bit body to the axial center. The roller cone cutting elements overlap with the fixed cutting elements in the nose and shoulder sections of the cutting profile between the axial center and the perimeter. The roller cone cutting elements crush and pre- or partially fracture formation in the confined and highly stressed nose and shoulder sections.

Abstract: A hybrid drill bit having both roller cones and fixed blades is disclosed. The cutting elements on the fixed blades form a continuous cutting profile from the perimeter of the bit body to the axial center. The roller cone cutting elements overlap with the fixed cutting elements in the nose and shoulder sections of the cutting profile between the axial center and the perimeter. The roller cone cutting elements crush and pre-fracture formation in the weak and highly stressed nose and shoulder sections.

Abstract: A bit body is configured at its upper extent for connection into a drillstring. At least one fixed blade extends downwardly from the bit body, and has a radially outermost gage surface. A plurality of fixed cutting elements is secured to the fixed blade, preferably in a row at its rotationally leading edge. At least one bit leg is secured to the bit body and a rolling cutter is mounted for rotation on the bit leg. At least one stabilizer pad is disposed between the bit leg and the fixed blade, the stabilizer pad extending radially outward to substantially the gage surface. The radially outermost gage surface of each blade can extend axially downward parallel to the bit axis or angled (non-parallel), spirally or helically, relative to the bit axis.

Abstract: An earth-boring bit comprising a bit body configured at its upper extent for connection into a drillstring. A selected number of fixed blades extend downward from the bit body and a selected number of rolling cutters are mounted for rotation on the bit body. A plurality of rolling-cutter cutting elements are arranged on each rolling cutter and a plurality of fixed-blade cutting elements are arranged on each fixed blade. The selected number of fixed blades exceeds the selected number of rolling cutters by at least one.

Abstract: The invention disclosed and taught herein is directed to an improved hybrid drill bit having at least two rolling cutters, each rotatable around an axis of rotation, at least one of the rolling cutters having a high pin angle, and at least one fixed blade. The increase in the pin angle can encompass pin angles above 39 degrees to less than 393 degrees. In at least one embodiment, the improved drill bit expands the capabilities of a hybrid bit to allow the rolling cutters to engage a shoulder portion and/or gage portion of the bit profile and assist the fixed blade(s) in these areas.

Abstract: The invention disclosed and taught herein is directed to an improved hybrid drill bit and associated elements having at least two rolling cutters, each rotatable around separate spindles on the bit, and at least one fixed blade. The improved drill bit expands the pilot pin to journal diameter ratio within the body of the rolling cutter, but within the confines of the allowable space of the rolling cutter.

Abstract: A high aspect ratio seal is provided for large roller cone drill bit having a diameter of greater than about 12¼ inches wherein the contact width is narrowed, relative to the width of the seal, to provide a desired contact width.

Abstract: An apparatus and method for retaining a roller cone on a bearing pin of a drillbit body.

Abstract: An earth-boring bit comprising a bit body configured at its upper extent for connection into a drillstring. A selected number of fixed blades extend downward from the bit body and a selected number of rolling cutters are mounted for rotation on the bit body. A plurality of rolling-cutter cutting elements are arranged on each rolling cutter and a plurality of fixed-blade cutting elements are arranged on each fixed blade. The selected number of fixed blades exceeds the selected number of rolling cutters by at least one.

Abstract: An earth boring bit has three cones, each cone being mounted for rotation about a cone axis while the bit rotates about a bit axis. An outer row and an adjacent row of cutting elements are integrally formed on each of the cones. Each of the cutting elements of the adjacent row on each of the cones has a crest extending perpendicular to a direction of rotation of the cone. Annular spaces are located between the outer row and the adjacent row on each of the cones. The annular space on one cone has a width that is less than the annular spaces on the other cones. The width of the narrowest annular space is greater than the width of the crests of the adjacent row.

Abstract: A rock drilling bit having PDC radial bearings has journal and cone bearing surfaces with increased contact area to increase load support. The radius of curvature of the bearing pin journal and cone bearing surfaces are matched or conformed on the bearing pressure side. The conformal journal surfaces may be formed on the main journal bearing, the pilot pin radial bearing, or both surfaces. In addition, diamond inlays may be located on the bearing surfaces of the cone, the bearing pin, or both components.

Abstract: An earth-boring bit comprising a bit body is cofigured at its upper end for connection into a drillstring. A fixed blade depends axially downwardly from the bit body. An axially extending slot is formed in the bit body adjacent the fixed blade. A bit leg is received and retained in the slot by engagement between the slot and correspondingly shaped bit leg, wherein the bit leg cannot be removed from the slot except by axial movement relative to the bit body. A rolling cutter is secured to the bit leg at its lower extent. A fastener secures the bit leg against movement relative to the bit body and extends through oblong apertures in the bit leg and into the bit body, wherein the bit leg can be moved axially relative to the bit body to adjust the projection of the rolling cutter relative to the fixed blade. The slot defines a pair of generally opposed sides connected by a third side, the generally opposed sides being inclined toward one another to define a dovetail that corresponds with the shape of the bit leg.

Abstract: A hybrid earth-boring bit comprising a bit body having a central axis, at least one, preferably three fixed blades, depending downwardly from the bit body, each fixed blade having a leading edge, and at least one rolling cutter, preferably three rolling cutters, mounted for rotation on the bit body. A rolling cutter is located between two fixed blades.