Abstract: The present invention addresses this need in the art by providing a cutter insert comprising a plug section and a cutter pedestal. The cutter insert in preferably formed of tungsten carbide, except for two exterior surfaces covered with PDC. The plug section may be circular or oval in cross section perpendicular to the axis of the insert. The plug section and the pedestal each defines a shoulder which is coated with a PDC layer. In this way, two cutting surfaces are applied to the formation, enhancing the cutting ability of the insert.

Abstract: The present invention addresses this need in the art by providing a cutter insert comprising a plug section and a cutter pedestal. The cutter insert is preferably formed of tungsten carbide, except for two exterior surfaces covered with PDC. The plug section may be circular or oval in cross section perpendicular to the axis of the insert. The plug section and the pedestal each defines a shoulder which is coated with a PDC layer. In this way, two cutting surfaces are applied to the formation, enhancing the cutting ability of the insert.

Abstract: A modular kerfing rock drilling bit (10) is presented. Drill bit (10) comprises a bit body (12) having a connection (14) for attachment to a drill string member. A base portion (16) below the connection (14) has an outer portion (18) and a bottom (20). Slots (22) are formed in the base portion (16). A cutter assembly (100) comprises a leg (110) insertable into the slot (22) of the bit body (16). A journal (126) extends angularly downward and inward from the leg (110) for bearing support of a cone (180) rotatably mounted on the journal (126). A plurality of cutters (182) extend outward from the surface of the cone (180). A kerfing segment (140) extends downward from the leg (110) beyond the cone (180). A plurality of kerf cutters (142) are attached to the bottom of the kerfing segment (140).

Abstract: The present invention addresses this need in the art by providing a cutter insert comprising a plug section and a cutter pedestal. The cutter insert is preferably formed of tungsten carbide, except for two exterior surfaces covered with PDC. The plug section may be circular or oval in cross section perpendicular to the axis of the insert. The plug section and the pedestal each defines a shoulder which is coated with a PDC layer. In this way, two cutting surfaces are applied to the formation, enhancing the cutting ability of the insert.