Abstract: A drill bit having a bit body, at least one roller cone attached to the bit body and able to rotate with respect to the bit body, and a plurality of cutting elements disposed on the at least one roller cone is disclosed. At least one of the plurality of cutting elements includes a first area defining a trailing edge, a second area proximate the first area defining a main wear surface, and a third area proximate the second area and defining a leading edge relief zone. Further, an insert for a drill bit having a contact portion adapted to contact an earth formation, the contact portion including a first area defining a relieved trailing edge, a second area defining a main wear surface, and a third area proximate the second area and defining a leading edge relief zone.

Abstract: A shaped insert that includes a top portion, and a grip length, wherein the grip length is modified to have a non-uniform cross sectional area is disclosed. In another case, a shaped insert includes a top portion, and a grip length, wherein the grip length is modified such that the insert is non-cylindrical. In another case, a shaped insert includes a top portion, and a grip length, wherein the grip length is coated in a non-uniform manner.

Abstract: Methods and apparatus for maintaining lubrication of rolling cone cutters mounted on journal pins. Embodiments comprise a rotating cone disposed on a journal pin and forming a journal gap there between. A cylindrical journal sleeve is disposed in the journal gap. The journal sleeve has a longitudinal gap forming opposing end portions, which are continuously contoured. A lubrication port is disposed in the journal pin and in fluid communication with a lubrication supply. The lubrication port has an outlet located in a recess in the journal gap. Each end of the recess comprises a transitioning surface extending between the bottom of the recess and the outer surface of the journal pin to prevent sharp transitions. In certain embodiments, the journal pin may comprise two or more lubrication ports, each located in a recess with transitioning surfaces.

Abstract: A drill bit that includes a bit body, at least one roller cone attached to the bit body and able to rotate with respect to the bit body, a plurality of cutting elements disposed on the at least one roller cone, and a barrel axis is disclosed. At least one of the plurality of cutting elements includes a first area defining a secondary wear surface, wherein the first area is formed as a convex surface on the trailing edge, a second area proximate the first area defining a main wear surface, wherein the second area is formed as a convex curved surface having a radius of curvature substantially equal to a radius of a borehole, and a third area defining a spherical cutting surface. Further, at least one of the plurality of cutting elements includes a non-spherical transition zone disposed between the third area and the first and second areas, wherein the barrel axis intersects the transition zone.

Abstract: A drill bit that includes a bit body, at least one roller cone attached to the bit body and able to rotate with respect to the bit body, and a plurality of cutting elements disposed on the at least one roller cone is disclosed. At least one of the plurality of cutting elements includes a first area defining a trailing edge, and a second area proximate the first area defining a main wear surface.. Further, an insert for a drill bit that includes a contact portion adapted to contact an earth formation, the contact portion including a first area defining a relieved trailing edge, and a second area defining a main wear surface, wherein a surface of the second area is a curved surface having a radius of curvature substantially equal to a radius of a borehole is also disclosed.

Abstract: A rotary drill bit for boring a bore hole in an earthen formation includes a bit body having a pin end, a cutting end and a longitudinal axis and including at least two legs extending from the cutting end. Each of the legs includes a leading side surface, a trailing side surface, and a shoulder, and each of the legs further includes a bearing and a cutter cone rotatably supported on the bearing. The bit body further including a fluid flow system that includes a flowway in the pin end. The flowway is in fluid communication with at least one exit port in the cutting end. The bit body further includes a neck between the shoulders and the pin end and a hard, wear-resistant material on at least a portion of the neck.