Abstract: A pressure compensation assembly for a drill bit having a cavity to receive the pressure compensation assembly, a mud port connected to the cavity, and a lubricant passageway connected to the cavity, is disclosed. The pressure compensation assembly includes a relief mechanism having a selected operating pressure. The pressure compensation assembly is movable from a first position to a second position within the cavity. The pressure compensation assembly may receive lubricant at a pressure exceeding the selected operating pressure to permit the flow of lubricant into the lubricant passageway while substantially preventing the release of lubricant into the mud port while in the first position. The pressure compensation assembly is operable to limit a pressure differential within the drill bit while in the second position.

Abstract: A pressure compensation assembly for a drill bit having a cavity to receive the pressure compensation assembly, a mud port connected to the cavity, and a lubricant passageway connected to the cavity, is disclosed. The pressure compensation assembly includes a relief mechanism having a selected operating pressure. The pressure compensation assembly is movable from a first position to a second position within the cavity. The pressure compensation assembly may receive lubricant at a pressure exceeding the selected operating pressure to permit the flow of lubricant into the lubricant passageway while substantially preventing the release of lubricant into the mud port while in the first position. The pressure compensation assembly is operable to limit a pressure differential within the drill bit while in the second position.

Abstract: An insert for an earth boring drill bit, such as a PDC rock bit or a roller cone rock bit, is provided. The insert includes a base integrally joined to a top section, the top section having a first flank that curves in a substantially helical manner about a longitudinal axis of the insert to join a crest.

Abstract: A rotary cone drill bit (20 and 120)is provided with inserts (70 and 90) and compacts (50 and 150) having contoured cutting portions (66, 166, 72 and 92). The rotary cone drill bit (22 and 122) includes a bit body (26 and 126) having at least one downwardly extending arm (28) terminating in a spindle (40). A cutter cone (30) with a gauge face surface (62) and a plurality of holes (64) formed therein, is rotatably mounted on each spindle (40). A compact (50 and 150) having a cutting portion (66 and 166) with a radius approximately equal to the desired radius for the resulting borehole (100) is press fit into each hole (64) in the gauge face surface (62). A number of inserts (70 and 90) are also installed in the exterior of each support arm (28). Inserts (70 and 90) have a contoured cutting surface with a radius approximately equal to the desired radius for the resulting borehole (100).