Abstract: An earth-boring bit has a bit body and at least one cantilevered bearing shaft depending inwardly and downwardly from the bit body. A cutter is mounted for rotation on the bearing shaft and includes a gage surface and an adjacent cutter backface. The cutter has negative offset with respect to the axis and direction of rotation of the bit. A plurality of cutting elements are arranged on the cutter including a plurality of gage cutting elements on the gage surface of the cutter. At least one of the gage cutting elements projects beyond the gage surface and defines a cutting surface facing the backface of the cutter for engaging the sidewall of the borehole being drilled as the gage cutting element moves up the sidewall.

Abstract: A roller cone rock bit (10) is provided that has improved cutter cone gauge face surface compacts. The roller cone rock bit (10) includes a bit body (12) having at least one downwardly extending arm (28) terminating in a spindle (30). A cutter cone (20) has a gauge face surface (24) and has a plurality of holes (45) formed in the gauge face surface (24). Each hole (45) in the plurality of holes has an axis (52) oriented at an acute angle with respect to the gauge face surface (24). A bearing assembly (32, 34 and 36) is disposed between the spindle (30) and the cutter cone (20) for rotary load-bearing engagement. A plurality of compacts (22) are disposed in the plurality of holes (45). Each compact (22) is oriented at an acute angle with respect to the gauge face surface (24) according to the axis (52) of each hole (45).

Abstract: A rotary cone drill bit for forming a borehole having a bit body with an upper end portion adapted for connection to a drill string. The drill bit rotates around a central axis of the body. A number of support arms are preferably extend from the bit body. The support arms may either be formed as an integral part of the bit body or attached to the exterior of the bit body in pockets sized to receive the associated support arm. Each support arm has a lower portion with an inside surface and a spindle connected thereto and an outer shirttail surface. Each spindle projects generally downwardly and inwardly with respect to its associated support arm. A number of cutter cone assemblies equal to the number of support arms are mounted respectively on the spindles. A throat relief area is provided on the lower portion of each support arm adjacent to the associated spindle to increase fluid flow between the support arm and the respective cutter cone assembly.

Abstract: A rotary cone drill bit for forming a borehole having a bit body with an upper end portion adapted for connection to a drill string. A number of support arms extend from the bit body. Each support arm has an exterior surface. A number of cutter cone assemblies equal to the number of support arms are mounted respectively on the support arms and project generally downwardly and inwardly with respect to an associated support arm. A ramp is formed on the exterior surface of the support arm and is inclined at an angle from a leading edge of the support arm toward a trailing edge of the support arm such that the ramp directs cuttings upward in the borehole.

Abstract: A method to back ream a borehole drilled with a roller cone drill bit is taught. Protruding hard metal cutting inserts are affixed on the upper outside diameter tapered shoulder of each of the bit legs. If the borehole closes to a smaller diameter than the bit gage diameter or loose rock rubble packs around the upper portion of the bit, the protruding cutting inserts fixed on the upper leg tapered shoulder portion back ream the borehole by lifting and rotating the bit.

Abstract: A rolling cone drill bit is disclosed having gage inserts which are installed so as to create a relief angle between the outer surface of each insert and the sidewall of the borehole. Each gage insert only engages the sidewall at a leading edge of the outer surface of the insert.

Abstract: An earth-boring bit has a cutter provided with hard gage inserts that protrude from the gage surface of the cutter to engage the side of the borehole for holding gage. The gage insert has a substantially flat, polygonal face, the sides of the polygonal face defining at least a pair of sharp cutting edges and at least a pair of cutting surfaces that define a negative rake angle with respect to the sidewall of the borehole that is being sheared by the gage insert. The face, cutting edge, and cutting surface of the gage insert are formed of a super-hard and abrasion-resistant material such as polycrystalline diamond or cubic boron nitride. The body of the insert is formed of a hard, fracture-tough material such as cemented tungsten carbide. The improved gage inserts are secured into sockets in the gage surface of the rolling cone cutter by interference fit.

Abstract: Method for casing a hole drilled in a formation having an enlarged section located below a previously cased section. The method includes running casing into the enlarged section wherein the casing is of slightly smaller diameter than that present in the previously cased section, pumping cement into the annulus formed between the outer surface of the casing and the enlarged section of the formation, providing a valve arrangement in the casing to permit circulation of the cement between the annulus and an inner portion of the casing, securing the casing in position within the hole and hanging and packing off in the last casing string. Finally, the previously cased string is latched and sealed to the last casing string.

Abstract: A cutter of an earth-boring bit is provided with hard gage inserts that protrude from the gage surface of the cutter to engage the side of the borehole for holding gage. The gage insert has a substantially flat face with sharp cutting edges formed thereon and has cutting surfaces that define a negative rake angle with respect to the sidewall of the borehole that is being sheared by the gage insert. The face, cutting edge, and cutting surface of the gage insert are formed of a super-hard and abrasion-resistant material such as polycrystalline diamond or cubic boron nitride. The body of the insert is formed of a hard, fracture-tough material such as cemented tungsten carbide. The improved gage inserts are secured into sockets in the gage surface of the rolling cone cutter by interference fit. The improved gage inserts provide an actively cutting gage surface that engages the sidewall of the borehole to promote shearing removal of the sidewall material.

Abstract: An improved rotary rock bit having a circumferential row of wear resistant inserts protruding from the gage surface of each rolling cone cutter. The inserts are designed to efficiently break and remove earth formations. Adequate clearance is provided around the gage inserts for chip formation, chip removal, and insert cooling. These rows of inserts provide reaming action to maintain borehole gage diameter after the primary gage cutting structure has worn or failed.

Abstract: A device for drilling deep holes in the ground has at least two axial drill bits and an equal number of plates each having three shafts axially interconnecting the plates. Two of the shafts are rigidly attached to both plates and the third shaft is pivotably attached to both plates. The two rigid shafts are separable from the upper plate by pulling a locking pin separating a telescopic head of each shaft from the plate. At the separation, the shafts are telescopically shortened by springs and the drilling liquid is automatically shut off to the worn-out drill bit and opened to the new drill bit. The remaining third shaft eccentrically interconnects the plates, whereby the lower worn-out drill bit, at rotation, wears a semicircular evacuation pocket in the wall of the hole. The third shaft is successively pivoted outwards until it forms an angle of e.g. 80.degree. with the axis of the hole. An axle pin having rectangular cross-section retains the upper end of the third shaft via a sleeve with a slit.

Abstract: A drilling tool for use in drilling operations for providing shock absorption capability and lateral support to the rotary drill string. The telescoping axial load shock absorber is positioned immediately adjacent at least one lateral support provided by a reamer or stabilizer. The stabilizer preferably employs a removable fixed blade secured to the tool by an undercut groove. The roller cutter for a reamer is also mounted in a preferred unique manner with the mounting blocks secured in a recess having an undercut retainer portion in the event of bolting failure. The mounting's brackets may be formed integral of the tool body or attached by welding or the like. A preferred form of mounting a blade on a stabilizer tool is also disclosed.

Abstract: A rotary drill bit comprising a cutter bit (10) having a plurality of mutually displaced rows (12-17) of cutting means (11) extending in the circumferential direction of the cutter bit (10). The included cone angle (.alpha.) of the cutter bit (10) is larger than 90.degree. and adapted to the mutual positioning of the cutting means (11) on the cutter bit (10) in such a way that it is ensured that repetition of the pattern of the cutting means is avoided.

Abstract: In a borer head for drilling boreholes in rock structures and including a drive shaft connected to a drive of a drilling machine, a central shaft coupled to the drive shaft, and a tool holder with cutters driven by a planetary gearing connected to the central shaft, supporting elements, engageable with a cylindrical wall of the borehole being drilled, are provided. The supporting elements are operatively connected to the central shaft and also to the tool holder so that the tool holder is driven into a slow rotation about the central shaft.

Abstract: The present invention relates to a drill bit incorporating one or more rotary cutters. The rotary cutters are supported for rotation by a bearing assembly including ball bearings running in races in the rotary cutter and drill bit body. The bearing assembly further includes an annular bushing. A sealing assembly including an O-ring seal is provided to seal lubricant within the bearing assembly and prevent external contaminants from entering the bearing assembly. A corrosive environment has been found to increase the occurrence of stress fractures in the areas above the juncture of cutter supporting structure and the bit body. It has been found that a sacrificial anode partitioned about the surfaces of the juncture renders the surfaces cathodic and resist stress fracture.

Abstract: A rotary bit having a pair of semi-spheres rotating about a shaft extending from a center tongue. The semi-spheres include a plurality of cutters arranged in a predetermined fashion to maximize cutting efficiency. The semi-spheres may be disposed slightly off-center from the bit's axis of symmetry to bias the bit in a particular direction.

Abstract: A roller cutter for a rotary drill bit comprising a conical roller cutter body of metal, and a plurality of cutting elements secured to the outer surface of the roller cutter body primarily by welding and being substantially free of mechanical interconnection to the roller cutter body. Each cutting element is an elongate member having a base portion at one end thereof engageable with the roller cutter body and a tip portion at the other end thereof engageable with the formation to be drilled for drilling the formation.

Abstract: A drill bit assembly for a rotary drill having a source of fluid under pressure and three bearing mounted rotary cutting cones for drilling into relatively hard material comprises an elongated housing with a first end adapted for engagement with the drill and a second end including the cutting cones or tools for engagement with the material to be drilled. A plenum chamber is provided within the housing for receiving pressurized fluid and for dividing the pressurized fluid into three portions. A first portion of the pressurized fluid is directed downwardly for impringement upon the material being drilled to pick up and remove dust and cuttings from the vicinity of the cutting cones. A second flow of the pressurized fluid is directed upwardly to remove the dust and cutting cones from the drill hole. The third flow of fluid is directed through the cutting cone bearings to cool the bearings during the drilling operation.

Abstract: An earth boring bit has features to reduce stress concentration. The earth boring bit is of the type having three bit legs, each bit leg having a depending bearing pin for rotatably carrying a cutter. An annular fillet is formed at the junction of the bearing pin and the bit leg for receiving a seal ring. To relieve stress above the fillet and on the inside surface of the bit leg, a depression is formed. The depression is formed in the inside surface of the bit leg with a lower edge commencing at the top of the fillet. The depression is curved in vertical cross-section and is located behind the backface of the cutter.

Abstract: Drilling bits are disclosed which are particularly efficient drilling devices when used in soft plastic underground formations which normally are difficult or impossible to drill with conventional drilling bits. The bits of this invention are characterized by having relief openings formed in the individual cutting elements to provide extrusion of the soft formation face into removable chips.

Abstract: Each bucket includes a ground engaging leading portion characterized by roller cutter means alternating with scoop teeth transversely across the bucket. The scoop teeth on alternate buckets follow the path of roller cutter means on intermediate buckets. The scoop teeth on intermediate buckets follow the path of roller cutter means on alternate buckets.

Abstract: The present invention provides a rotary rock bit with a heat pipe for conducting heat from the bit's bearings. The rotary rock bit includes a bit body with a connection for connecting the bit body to a rotary drill string. At least one arm extends from the bit body and a rotatable cutter is mounted on said arm. Bearing means are located between the rotatable cutter and the arm for promoting rotation of the cutter. A heat pipe is positioned in the bit body and the heat pipe extends into the arm. The heat pipe includes an evaporator section located near the bearings and a condenser section located near the external surface of the bit.