Abstract: A rock bit for blast hole drilling includes: a bit body having a coupling formed at an upper end thereof, a plurality of lower legs, a dome formed between the legs, and a bore formed through the coupling and the dome; a plurality of skirts, each skirt covering a gap formed between adjacent legs and each skirt mounted to edges of adjacent legs; a plurality of roller cones, each rotary cone rotatably mounted to a respective bearing shaft of a respective leg; a row of gage cutters mounted to each roller cone; a row of inner cutters mounted to each roller cone; one or more nose cutters mounted to each roller cone; and a center jet secured in the bore. Each cutter is an insert.

Abstract: A rock bit for blast hole drilling includes: a bit body having a coupling formed at an upper end thereof, a plurality of lower legs, a dome formed between the legs, and a bore formed through the coupling and the dome; a plurality of skirts, each skirt covering a gap formed between adjacent legs and each skirt mounted to edges of adjacent legs; a plurality of roller cones, each rotary cone rotatably mounted to a respective bearing shaft of a respective leg; a row of gage cutters mounted to each roller cone; a row of inner cutters mounted to each roller cone; one or more nose cutters mounted to each roller cone; and a center jet secured in the bore. Each cutter is an insert.

Abstract: A choke assembly for controlling air flow into a piston of a percussion tool for downhole drilling includes a choke and a choke adapter. The choke comprises a choke body and a choke opening in the choke body for fluid to flow therethrough. The choke further includes one or more arm slots formed into the choke body between an inner wall of the choke body and an outer wall of the choke body. The one or more arm slots are designed to receive one or more arms of a choke change tool. The choke adapter has an adapter opening extending through the choke adapter. The choke is sized to fit in the adapter opening. The choke is removable from the choke adapter after the choke is inserted into the adapter opening.

Abstract: A rotary cone drill bit includes: a body, a leg depending from the body, a bearing shaft extending from the leg and a cone mounted to the bearing shaft. The leg includes a leading transitional surface. A bottom surface of a hard material plate is attached to a substantially conforming surface of the leg in a position where the hard material plate is disposed on a floor surface formed in or by the leading transitional surface of the leg.

Abstract: An earth boring drill bit having an alternate path to allow cuttings to be ejected or evacuated from the drill bit and up the bore hole is disclosed. The evacuation hole of the present disclosure allows larger sized cuttings to evacuate from the bit without having to be continually ground by rolling cone cutters until the cuttings are small enough to follow a path around the edge of the shirttail of the bit and up the borehole. A cuttings restrictor is disposed at the inlet of the evacuation hole. The cuttings restrictor ensures that only cuttings that are sized to move completely through the evacuation hole and exit the drill bit are allowed to enter the evacuation hole.

Abstract: A choke assembly for controlling air flow into a piston of a percussion tool for downhole drilling includes a choke and a choke adapter. The choke comprises a choke body and a choke opening in the choke body for fluid to flow therethrough. The choke further includes one or more arm slots formed into the choke body between an inner wall of the choke body and an outer wall of the choke body. The one or more arm slots are designed to receive one or more arms of a choke change tool. The choke adapter has an adapter opening extending through the choke adapter. The choke is sized to fit in the adapter opening. The choke is removable from the choke adapter after the choke is inserted into the adapter opening.

Abstract: In an embodiment, a rotary cone drill bit comprises: a body, a leg depending from the body, a bearing shaft extending from the leg and a cone mounted to the bearing shaft. The leg includes a leading transitional surface. A bottom surface of a hard material plate is attached to a substantially conforming surface of the leg in a position where the hard material plate is disposed on a floor surface formed in or by the leading transitional surface of the leg.

Abstract: An earth boring drill bit having an alternate path to allow cuttings to be ejected or evacuated from the drill bit and up the bore hole is disclosed. The evacuation hole of the present disclosure allows larger sized cuttings to evacuate from the bit without having to be continually ground by rolling cone cutters until the cuttings are small enough to follow a path around the edge of the shirttail of the bit and up the borehole. A cuttings restrictor is disposed at the inlet of the evacuation hole. The cuttings restrictor ensures that only cuttings that are sized to move completely through the evacuation hole and exit the drill bit are allowed to enter the evacuation hole.

Abstract: A rolling cone cutter for a roller cone earth-boring bit has a generally conical body. The generally conical body defines a plurality of lands and grooves. Each land supports a circumferential row of primary cutter elements. At least one of the plurality of lands has a land sidewall. The land sidewall defines a boundary of an adjacent groove. A plurality of protective inserts are disposed within the land sidewall. The protective inserts may reduce erosion of the land sidewall. One or more protective inserts may be disposed between a pair of primary cutters.