Abstract: There is disclosed herein drilling apparatus, in particular for use in the field of oil prospecting, comprising: a first tubular member (1, 2, 3); a second tubular member (6, 7, 8, 9) mounted at least partly within the first tubular member so as to be reciprocally free in rotation with respect to the first tubular member about an axis (5); and a drill bit (4) operatively connected to one of the first or second tubular members so as to be rotated in response to the one tubular member being turned in order to effect drilling, characterised in that: the drilling apparatus further comprises a restoring member (18, 36) for applying a forces between the first tubular member and the second tubular member at least in respective first axial directions in response to relative displacement of the first tubular member and the second tubular member in the respective opposite axial directions. Also provided are a tubular assembly and a method of assembling tubular members.

Abstract: A rotating cone drill bit includes a plurality of mud nozzles extending from the bit body, which are thermally fitted by controlling the temperature differential of 300° F.-900° F. depending on the corresponding materials of the elements to be fitted, the amount of fit desired, and the diameters of the elements to be fitted and which provide substantially obstruction-free mud paths toward the wellbore bottom. The bit has a plurality of reduced diameter cutter assemblies, each having a journal projecting from a corresponding leg. The journal has at least two cylindrical bearing surfaces and an annular groove formed therebetween and a spindle. An annular retention segment is rotatably mounted in the groove. The retention segment has an outer radial surface engaging a portion of one of the bearing surfaces of the cone, and an energy beam welding area fusing substantially the entire engaging surfaces of the retention segment and the cone.

Abstract: The present disclosure relates to a microtunnelling apparatus including a cutting apparatus adapted to be rotated by a drill shaft defining a central axis of rotation that extends along a length of the drill shaft. The cutting apparatus includes a front cutting rotor having a hub defining a shaft receiver that extends at least partially through the hub in a direction extending from a back side toward a front cutting side of the front cutting rotor. The shaft receiver is configured to receive the drill shaft. The drill shaft and the shaft receiver cooperate to define a torque transmitting mechanical interface for allowing torque to be transferred between the drill shaft and the front cutting rotor such that the drill shaft can be used to rotate the front cutting rotor about the central axis of rotation. The front cutting rotor also includes a plurality of cutting bars that project at least partially radially outwardly from the hub.

Abstract: An improved hole opener assembly for horizontal drilling is disclosed that is less prone to failure as a result of cone arm break out or pocket side wall fracture. The interface between the cone arm and the pocket employs a key and slot configuration with a tighter fit than between the arm and the pocket to reduce the stress on the pocket side wall during drilling.

Abstract: A roller cone bit having a sealed lubricant reservoir between a roller cone and a head section. A journal sleeve is included on the head section that circumscribes the journal bearing surface of the head section. The sleeve can axially pivot on the head section, but does not rotate thereon. The reservoir is formed into a journal bearing surface of the head section body and may be sealed by placing a seal around its periphery that extends between the journal bearing surface and journal sleeve. Sealing the reservoir results in a hydrostatic condition therein and substantially equalized pressures.

Abstract: An earth bit includes a cone rotatably mounted to a shaft with a hub unit and thrust roller bearings. The hub unit is moveable between mounted and unmounted positions on the shaft, as a single unit, in a repeatable manner. The hub unit includes a pair of roller bearings positioned between inner and outer races. The outer race includes a recess extending around its outer periphery. A sealing structure is slidingly engaged with the recess to provide a seal between the cone and shaft.

Abstract: A rotary mine drilling bit for making blast holes having a connection at one end of the body for attachment to a drill string and the second end of the body having a plurality of longitudinally extending slots. A thrust shoulder is provided between the ends of the body and longitudinally extending supporting legs are positioned in each of the slots and are releasably connected to the body. One end of the supporting legs are positioned the adjacent the shoulders for receiving longitudinal thrust and for avoiding thrust on the connecting means. A roller bit is connected to the end of each supporting leg.

Abstract: A method for manufacturing drill bits in segments, using a single key which is nowhere concave in its axial profile to position all three segments together for welding; and drill bits so made.

Abstract: A rotary cone drill bit for forming a borehole having a bit body with an upper portion adapted for connection to a drill string. A number of support arms extending from the bit body with each support arm having an exterior surface with an opening extending therethrough. A number of cutter cone assemblies equal to the number of support arms with each cutter cone assembly rotatably mounted on a respective spindle projecting generally downwardly and inwardly from each support arm. A ball retainer passageway extending from the opening in the exterior surface of each support arm to allow installing ball bearings through the opening and the ball retainer passageway to rotatably mount each cutter cone assembly on its respective spindle. A ball race formed in the exterior of each spindle between a first outside diameter portion and a second outside diameter portion. The ball retainer passageway intersecting the ball race.

Abstract: Small diameter rotary drill bits using rolling disc cutters. Novel small diameter rotary drill bits with detachable pedestal mounted rolling disc cutters are provided. The bit body has a plurality of longitudinal edge mounting slots located at preselected angularly spaced apart locations. Preferably, the slots each have an upper protective ledge and downwardly extending sidewalls. A set of peripheral pedestal mounts each having a mounting portion sized and shaped to fit into a preselected mounting slot are provided and each is detachably mounted in its preselected mounting slot. In one embodiment, the longitudinally extending slots further comprise a wedge shaped edge portion, and the pedestal mounts have a complimentary angularly shaped portion, so that when the pedestal mount is brought into a close fitting relationship with the longitudinal slot, the pedestal mount and the longitudinal slot are tightly and securely interfitting.

Abstract: A method and apparatus are provided for use in fabricating rotary cone drill bits from multiple drill bit segments. Each drill bit segment (40) preferably includes a first portion (50) with mating surfaces (61, 62) designed to be aligned with mating surfaces (61, 62) of other drill bit segments (40) and a second portion (80) which includes a support arm (90) with a cutter cone assembly (100) rotatably mounted thereon. A recess (70) having a generally spherical surface is formed within the first portion (50) of each drill bit segment (40) such that when the respective drill bit segments (40) are aligned with each other, the spherical recesses (70) cooperate with each other to define a generally spherical cavity. A ball (72) is disposed within the resulting spherical cavity when the drill bit segments are joined with each other to form the bit body (42) for the resulting rotary cone drill bit (20).

Abstract: A mounting for cutter wheels on rotary rock drill bits includes a spindle with two annular axial load bearing surfaces, one of which interfaces in a rotational relationship with a cylindrical segmented bushing affixed to the inside surface of a cavity in the cutter wheel and the other of which interfaces through a top hat bushing flange in a rotational relationship with an annular end bearing surface in the cavity of the cutting wheel. A compressive silver coating on the cylindrical bushing before it is split, leaving uncoated edges for precise registration and bit onto a cylindrical race surface machined into the spindle, provides lubrication in addition to compressing under load to distribute axial loading forces from the cutter wheel in proportion to the two axial load bearing surfaces on the spindle.

Abstract: A boring head is provided for use in mounting to a drill pipe of a drilling rig for enlarging a pilot bore in horizontal boring operations. The boring head has an axial member positioned along a central axis of the boring head for connecting the boring head to the drill pipe of the drilling rig. A plurality of internally tapered longitudinal pockets around the periphery of the axial member each receive an externally tapered body mounting an independently rotatable cutter bit which rotates about a rolling axis inclined at an angle in the range between ten and eighty degrees with respect to the central axis of the boring head. The tapered body is drawn into the tapered pocket by a threaded retainer and forced into the pocket when boring by the force of the boring head against the bore face.

Abstract: A modular drill bit mounts legs within recesses in a body which are parallel to the central axis of the body using threaded studs with tapered outer portions, in conjunction with an attached pin having recesses therein receiving the upper ends of the legs. The lower ends of the legs terminate in spindles of open face configuration rotatably receiving cones thereon for rotation via a arrangement of bushings, roller bearings and thrust bearings, and a plurality of seals which slide and therefore rotate relative to both the leg spindle and the cone with the help of pressure compensating apparatus. A bushing disposed in the cone-leg spindle interface has oil-lubricated rubber rods disposed in apertures therein to prevent lock-up on an adjacent bearing surface. The cone is held in the leg spindle by a lock nut forming one end of a race for receiving rollers of a roller bearing, in conjunction with a ring-nut secured to an extended portion of the cone protecting the leg from wear and damage.

Abstract: A drill bit for use in drilling a well bore in accordance with this invention comprises a main drill body adapted to be rotated about a substantially vertically disposed axis of rotation and having therein a duct extending longitudinally along such axis, for supplying a drill fluid under pressure to the well bore. Three generally circular, rotatable cutting discs are mounted on the outside of the main drill body at equally spaced locations, with the cutting discs each having cutting elements disposed in a ring-shaped array. Each of the cutting discs has an axis of rotation disposed at an acute angle to the vertical centerline about which the main drill body rotates. Importantly, the axis of rotation of each cutting disc is slightly offset from the centerline of the main drill body, thus to cause the cutting discs to be positioned to be particularly effective and aggressive in cutting the well bore.

Abstract: An earth boring bit having an improved two piece bearing and seal assembly containing a cantilevered bearing lug that is threaded to receive a mating bearing sleeve, the lug having a transverse shoulder intersected by a mouth on the sleeve to define a bearing shaft upon which is supported a rotatable cutter. A lubrication system includes a hydrostatic pressure compensator and seal means, the transverse shoulder being positioned inwardly of the seal means toward an inner end region of the lug to avoid exposure of the transverse shoulder of the lug and the mouth of the bearing sleeve to ambient drilling fluid. The seal means is a rigid face seal assembly which includes a rigid, sealing ring and a resilient energizer ring.

Abstract: An earth boring bit having a cantilevered bearing shaft and a compensator system to equalize the pressure of the lubricant with the hydrostatic pressure of the drilling fluid surrounding the bit. A rigid face seal assembly, positioned between the cutter and bearing shaft of the bit, moves axially in response to, and to compensate for, dynamic pressure changes in the lubricant adjacent the seal. The positioning and sizing of resilient energizer rings in relationship to the geometries of the mating grooves between the cutter and shaft and the rigid sealing rings of the face seal assembly minimize axial seal movement relative to cutter and shaft during drilling to enhance seal life. A threaded bearing lug receives an internally threaded bearing sleeve. The journal bearing surface is approximately midway between the shaft seal groove, a portion of which is on its bearing sleeve and another portion on the cutter seal groove.

Abstract: A rotary drill for drilling a well in the surface of the earth the drill comprising a drill bit including an upper portion for connection to a drill string, duct means for carrying fluid to extract detritus and clear the bottom of the well and receiving means; a solid cutting head comprising a conical head portion and a stem portion, the conical head portion including holes therein and cutting elements inserted in the holes, the stem portion being received in the receiving means of the drill bit, wherein the stem and the receiving means include holding means for rotatably holding the cutting head in the drill bit; bearing means between the drill bit and the conical head; and a lubrication system interconnected between the drill bit and the cutting head.