Abstract: A fixed-cutter drill bit for boring through earth has a body made predominately of high strength steel with thin erosion and abrasion resistant surfaces integrally formed in the steel in areas likely to encounter abrasive or erosive conditions. The drill bit may be formed by a rapid solid state densification (RSSDPM) process. The drill bit combines the high strength of conventional steel bits with design freedom and hardness equal to or greater than conventional matrix bits. Due to the manner in which the hard particles, such as tungsten carbide, are integrally held in a steel matrix, aggressive fluid hydraulics may be employed with the drill bit without unduly limiting the performance of the drill bit.

Abstract: A rotary drill bit (10) has three roller cutters (20A, 20B and 29C) mounted thereon for rotation with a plurality of cutting elements (26) arranged in concentric annular rows (28A, 28B, 28C, 28D) thereon. A high velocity drilling fluid is discharged from nozzle orifices (40, 42, 52) and the orifices are sized and positioned so that more hydraulic energy is directed against the cutting elements (26) in the gage row (28D) than against the cutting elements (26) in the remaining rows (28A, 28B, 28C). The drilling fluid impinges the cutting elements (26) on the leading side of the roller cutters (20A, 20B, 20C) immediately prior to engagement of the cutting elements (26) with the bore hole bottom (30) and then sequentially strikes the bore hole bottom formation at or closely adjacent the juncture (35) of the horizontal bottom portion (32) with the vertical side portion (34).

Abstract: A rotary drill bit (10) having a plurality of roller cutters (20) with rows (32A, 32B, 32C, 32D) of cutting inserts (34,36,38,40) mounted within sockets (35,46) on the frusto-conical cutter body (30). The cutting inserts 34,36,38,40) have cutting surfaces formed with a wear-resistant material with certain cutting inserts (36,38) being formed of a wear-resistant material having a hardness higher than the hardness of the wear-resistant material on the remaining inserts (34,40) in each row. The hard cutting inserts (36,38) are positioned in each row in a predetermined pattern intermingled in a generally uniformly spaced pattern with the softer cutting inserts (34,40) and comprising generally between 20% and 50% of the total number of cutting inserts in a particular row.

Abstract: A drag type drill bit (10) having a plurality of solid block-like holders (30, 32, 34) secured to and projecting from the bit body (12), each holder (30) having a plurality of cutting elements (36) thereon defining spaced cutting edges 54. Each cutting element (36) has a planar cutting face (46) and a cutting edge (54) extending along the cutting face (46) with the cutting face (46) extending in a generally radial direction with respect to the axis of rotation of the bit (10). The holders (30, 32, 34) are arranged in a plurality of rows extending outwardly from adjacent the axis of rotation of the drill bit (10) and the holders (30, 32, 34) in each row are staggered rearwardly with respect to the direction of rotation.

Abstract: A triple cone drill bit (10, 10A) comprising a plurality of conical roller cutters (16, 16A) 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 (10, 10A), and a drilling fluid nozzle system for directing a pressurized fluid stream (76, 76A) 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 (10, 10A) 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. In one embodiment (FIGS. 15-20) the drill bit body (12A) has vertically extending recessed portions (21A) formed at the junctures (19A) of the lugs (15A) to provide flow passageways for the upward flow of drilling fluid and entrained cuttings.

Abstract: A drag type rotary bit (10) having a plurality of arcuate blades (24A-24E) each having a row of cutting elements (36A-36G) thereon. The cutting elements (36A-36G) are arranged on the arcuate blades (24A-24E) with around one-half of the length of the arcuate blades (24A-24B) being positioned adjacent the outer periphery (20) of the bit body (12) to provide a relatively long length mounting area or the cutting elements (36D-36G) at the gage (20). Deep grooves (26) are provided adjacent each of the blades (24A-24E) and provide a relatively large passage for the outwardly flow of drilling fluid and entrained cuttings.

Abstract: A drag type rotary bit (10) having polycrystaline diamond compact (PDC) cutting elements arranged in a plurality of rows extending from the center of the bit body (12) to the outer peripheral surface (20) thereof. A fluid discharge nozzle (38A-38F) is provided for each row of cutting elements (36A-36G) and has a fluid discharge stream (62) directed downwardly against the bore hole bottom (66) and opposite the direction of rotation of the bit (10) ahead of the associated row of cutting elements (36A-36G) for flowing against the cutting faces (53) of the cutting elements (36A-36G) after impingement of the bore hole bottom (66).

Abstract: A tri-cone drill bit (10, 10A) comprising a plurality of conical roller cutters (16, 16A) 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 (10, 10A), and a drilling fluid nozzle system for directing a pressurized fluid stream (76, 76A) 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 (10, 10A) 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. In one embodiment (FIGS. 15-20) the drill bit body (12A) has vertically extending recessed portions (21A) formed at the junctures (19A) of the lugs (15A) to provide flow passageways for the upward flow of drilling fluid and entrained cuttings.

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 dynamic seal is disclosed for sealing between a rotating cutter and a drill bit journal in an underground formation drilling bit, which seal utilizes a static elastomeric seal ring abutting a metal seal ring having a dynamic sealing face.