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 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 seal assembly (34) for a roller cutter drill bit (10). Seal assembly (34) has an elastomeric resilient O-ring 44 adjacent one sealing surface and a dynamic elastomeric O-ring (46) adjacent another sealing surface. A rigid carrier (52) is mounted between the O-rings (44, 46) which are unsecured to their associated sealing surfaces. A key (54) on carrier (52) limits rotation of the carrier (52) and static O-ring (46) relative to the associated sealing surface (38).

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 roller cutter drill bit comprises a body having a journal, a roller cutter, bearing means for rotatively mounting a roller cutter on the journal and a part of said bearing means including a hard, tough metal bushing with a lubricant metal coated thereon, and positioned between the sleeve and the journal and between the sleeve and the roller cutter to prevent galling.

Abstract: A roller cutter drill bit with a body having a journal, a roller cutter, bearing means for rotatively mounting the roller cutter on the journal and a part of said bearing means including a maraging steel sleeve with a lubricant between the sleeve and the journal and between the sleeve and the roller cutter to prevent galling.

Abstract: A drill bit having a roller cutter supported by ball bearings and a ball retainer retained in position both axially and rotationally within the ball loading hole by a plug which is mechanically wedged into secured and sealed position within the outer end of the ball loading hole.

Abstract: A drill bit having a body with a shaft thereon, a roller cutter, an annular thrust bearing, means for connecting said roller cutter to the thrust bearing, means for retaining said thrust bearing on the shaft, and a lubrication system containing the thrust bearing and the retaining means with the lubrication system seal positioned between the outer edge of the roller cutter and the base of the shaft.