Abstract: This invention discloses a rolling cone drilling bit having a plurality of cutters which have inserted therein hard metal cutting elements preferably formed of tungsten carbide alloy; and in which bit the rolling cone cutters are located in such a manner that their rotational axes are greatly offset from the rotational axis of the drill bit. In addition, a fluid jetting system is provided in the invention that directs a pressurized fluid spray across the main cutting inserts and against the formation face so that when the drill bit is used in its most advantageous areas, such as the soft, medium-soft and plastic formations, the jetting system prevents "balling up" of the cutters and greatly increases the drilling efficiency of the bit.

Abstract: This invention discloses a rolling cone drilling bit comprising a plurality of conical roller cutters having hard metal cutting elements thereon and being so positioned relative to each other that their rotational axes are offset from the rotational axis of the drill bit, and a drilling fluid nozzle system for directing a pressurized fluid stream across certain of the cutting elements and thereafter against the formation generally at the bottom of the well bore so that when the drill bit is used in its most advantageous areas, such as the soft, medium-soft and plastic formations, the nozzle system prevents "balling up" of the cutters and greatly increases the drilling efficiency of the bit.

Abstract: A nozzle system for a rotary drill bit comprising a plurality of elongate nozzle members detachably secured in drilling fluid exit bores in a drill bit body, each nozzle member having passaging therein, the lower portion of which is angled relative to the longitudinal axis of the nozzle member, and a projection and recess arrangement for holding each nozzle member in its bore in a predetermined angular position for directing the drilling fluid to flow in a stream along a line at a predetermined angle and in a predetermined position relative to an adjacent roller cutter of the drill bit for improved cleaning of the cutting elements and the formation.

Abstract: A rotary drill bit comprising a bit body adapted to be secured to a drill string and to receive drilling fluid under pressure therefrom, the body having a plurality of nozzles for exit of the drilling fluid, and a plurality of depending legs at its lower end. The bit further includes a plurality of roller cutters, one for each leg, each cutter comprising a generally conical cutter body rotatably mounted on the respective leg, and a plurality of cutting elements thereon. The cutter body at its conical surface is formed of a material resistant to erosion by high drilling fluid which may impinge it.

Abstract: A powder metallurgy composite material comprising grains of a relatively hard material and a binder for binding the grains together, the binder being metastable and transformable at ambient temperature by the application of mechanical force from an initial state in which the major phase of the binder is austentic to a second state in which the major phase of the binder is martensitic, whereby the binder, while undergoing this transformation, absorbs mechanical energy applied to the composite material for increasing its fracture toughness and resistance to fatigue crack nucleation and propagation. Also disclosed is a method of heat-treating the composite materials to improve their transformation-toughening characteristics. A heat-treatable composite material having such improved transformation-toughening properties is also disclosed.

Abstract: A rotary drill bit comprising a bit body having a plurality of drag cutting elements mounted on the bottom thereof. Each cutting element has a portion projecting down below the bit body and forward generally in the direction of rotation of the bit. This portion presents a leading face and a trailing face which converge at an acute angle to form a cutting edge. Each element is positioned on the bit body such that its leading and trailing faces present a positive rake angle and back clearance, respectively, to the surface of the well bore formation for improved cutting action. The bit body has an exit port at the bottom thereof for flow of drilling fluid under pressure, and sets of first and second generally parallel ridges defining watercourses extending from the exit port to the periphery of the bit. The cutting elements are mounted on the second or trailing ridge, and extend toward but stop short of the first or leading ridge.

Abstract: A drill bit comprising a bit body detachably secured to a drill string having a chamber therein to receive drilling fluid at a first pressure from the drill string, a nozzle for exit of the drilling fluid to the space between the bit body and the well bore at a second pressure lower than the first, and a depending leg; a roller cutter; a bearing assembly for rotatably mounting the roller cutter on the leg; a lubrication system in the bit body comprising a reservoir of lubricant, passaging for flow of lubricant from the reservoir to the bearing assembly, a seal member for blocking flow of lubricant out of the bit, an expansible chamber for pressurizing the lubricant to a third pressure greater than the second but less than the first, and a biased diaphragm for pressure compensation secured in a recess in the bit body in fluid communication at one side thereof with the lubricant and at the other side thereof with the drilling fluid in the space between the bit body and the well bore; and a sensor for sensing a

Abstract: A nozzle assembly for an earth boring drill bit of the type adapted to receive drilling fluid under pressure and having a nozzle bore in the bottom thereof positioned closely adjacent the well bore bottom when the bit is in engagement therewith with the bore having inner and outer portions. The nozzle assembly comprises a generally cylindrical nozzle member of abrasion and erosion resistant material, selected from a plurality of such members, each being of the same outer diameter but having passaging therein of different cross-sectional area. The nozzle member is adapted to be fitted in the inner portion of the nozzle bore in sealing relationship therewith for forming a first seal for the nozzle assembly. The nozzle assembly further comprises a locknut, separate from the nozzle member, for detachably securing the nozzle member in the nozzle bore, formed at least in part of an abrasion and erosion resistant material.

Abstract: A rotary drill bit comprising a bit body having a chamber therein adapted to receive drilling fluid under pressure, a plurality of nozzles in communication with the chamber for exit of the drilling fluid, and a plurality of depending legs at its lower end, each having a bearing journal. The bit further includes a plurality of roller cutters, one for each leg, each cutter comprising a generally conical cutter body rotatably mounted on the bearing journal of the respective leg, and a plurality of cutting elements thereon. Each nozzle has an orifice in a position below the top of an adjacent roller cutter but above the central axis of the respective bearing journal at its inner end with respect to the bit body.

Abstract: A friction bearing assembly for a roller cutter drill bit, comprising a first bearing member of cylindrical configuration and a second bearing member having an opening of generally circular section therein receiving the first member for enabling relative rotation of the members. A bushing is fitted between the bearing members, the bushing being of annular configuration and having an inner and an outer diameter so related to the diameter of the first bearing member and the diameter of the opening in the second bearing member as to enable the bushing to rotate relative to both members. The bushing is of width substantially greater than its thickness, and comprises a plurality of relatively thin, narrow elongate metal members, each metal member being of generally circular configuration and constituting a ring.

Abstract: A bit breaker adapted to be fitted in the Kelly drive of a drill rig for detachably securing a rotary drill bit to the Kelly drive to enable the latter to rotate the bit relative to a drill string having an internally threaded lower end portion in one direction to effect a threaded connection between the threaded pin of the bit and the string, and in the other direction to disconnect the bit from the string. The bit breaker comprises a bottom engageable by the bottom of a drill bit for supporting the bit, a top having an opening therein through which the bit may be lowered into engagement with the bottom of the bit breaker and may be raised to remove the drill bit from the bit breaker, and a stop member for selectively securing the bit in fixed annular position in the said opening in the bit breaker.

Abstract: A seal assembly for a rotary drill bit of the type comprising a bearing journal constituting a first bearing member, and roller cutter having a blind end bore therein, constituting a second bearing member, receiving the journal and an annular recess at the open end of the bore, the annular recess and journal defining an annular cavity in the bit. The seal assembly is positioned in the cavity for holding lubricant in the bit and comprises a ring of relatively rigid material movable with respect to the journal and the roller cutter in the longitudinal axial direction thereof and having a sealing face. An elastomeric seal member sealingly engages the movable ring and one of the bearing members and biases the ring to a position in which the sealing face of the ring is in sealing engagement.

Abstract: A valve system is disclosed for use in the lubrication passages of a rolling cutter drill bit, which valve assembly utilizes one or more reed valves to maintain flow of lubricant in a desirable direction.

Abstract: A rotary drill bit comprising a bit body having at least one depending leg at its lower end and at least one roller cutter rotatably mounted on the leg. The roller cutter comprises a frustoconical roller cutter body and a plurality of cutting elements projecting from the cutter body to tips adapted to bear on the bottom of the well bore, with the tips defining, upon rotation of the bit, a first cutting surface of the bit extending over substantially the entire area of the bottom of the well bore. At least one drag cutter extends down from the bit body and comprises a support and a plurality of drag cutting elements on the support, each having a lower cutting edge.

Abstract: A nozzle retention system is disclosed which serves to retain a jet nozzle in a drilling bit and also align the nozzle with respect to the bit cutters, said system utilizing a deformable pin and interacting channels in the nozzle and the bit nozzle bore.

Abstract: An oil well drilling bit is disclosed of the type utilizing hard metal inserts in the rolling cutters wherein each row of inserts on each cutter is located thereon in a sinusoidal or varying pattern rather than the strictly circumferential pattern of the prior art.

Abstract: A method of making a rolling cutter drill bit involving the steps of forming a body member having an upper portion adapted to be threaded and passaging therein, forming at least one arcuate recess in the lower end of the body member, providing a lug assembly comprising a lug member having a bearing journal carrying a rolling cutter and an arcuate surface adapted to be received in the recess, and securing the lug assembly in the recess with the arcuate surface of the lug member in engagement with the arcuate recess. A drill bit made according to the foregoing method is also disclosed.

Abstract: A rolling cutter rock drilling bit is disclosed which features an internal lubricant pump utilizing an internal elastomeric member moving across a grooved rigid surface to circulate lubricant in the bit bearings as a result of the shear forces on the lubricant created when the elastomer moves across the grooves.

Abstract: A method is disclosed for forming roller cutters and also for forming cutting teeth for rolling cutter bits, including cutter inserts, cutter teeth formed in place, or formed separately and welded in place, etc., by powder metallurgy as a densified powder metallurgical composite of at least two varying phases, the composite having a substantially continuous mechanical property gradient therethrough. The gradient is from one region having hardness or wear resistant properties to another region having toughness properties. The method comprises:providing a first powder mixture comprising a major proportion by volume of a powdered refractory compound and a minor proportion by volume of a powdered binder metal or alloy. Providing a second powder comprising a powdered binder metal or alloy or a mixture comprising a powdered refractory material and a powdered binder metal or alloy, present in a lesser proportion by volume than in the first powder.

Abstract: A lubrication system is disclosed for a rolling cutter drill bit, which system utilizes solid or semi-solid sticks of lubricants located in internal channels and continuously biased against rotating surfaces in the bit.