Abstract: An underreamer drill hammer comprising a canister including a housing having an outer diameter, a proximal end configured for attachment to a drill string, and a percussive drill hammer housed within the housing, the percussive drill hammer having a drill bit movable between a radially retracted position and a radially extended position. The drill bit can rotate and is designed in a manner that the drill bit head cams, pivots, or swings out to a larger cutting diameter when the system is rotated in a first direction. The system is rotated in a second direction to retract the bit heads. The bits are retracted to remove the canister from the casing or to drill a smaller diameter hole through rock.

Abstract: An underreamer drill hammer comprising a canister including a housing having an outer diameter, a proximal end configured for attachment to a drill string, and a percussive drill hammer housed within the housing, the percussive drill hammer having a drill bit movable between a radially retracted position and a radially extended position. The drill bit can rotate and is designed in a manner that the drill bit head cams, pivots, or swings out to a larger cutting diameter when the system is rotated in a first direction. The system is rotated in a second direction to retract the bit heads. The bits are retracted to remove the canister from the casing or to drill a smaller diameter hole through rock.

Abstract: A down-the-hole hammer comprising a housing and a drill bit disposed about a distal end of the housing. The drill bit includes a head, a shank extending from the head, the shank including a bore having a plurality of ribs, and an exhaust tube configured to be coupled to the shank, the exhaust tube including a plurality of ribs for engaging the counterbore of the shank.

Abstract: A down-the-hole drill hammer comprising a housing, a backhead connected to the housing, an accumulator housed within the housing and downstream the backhead, and a piston reciprocally mounted within the housing. The accumulator includes an accumulator housing, a liner within the accumulator housing, and a flexible diaphragm circumscribing the liner and within the accumulator housing.

Abstract: A down-the-hole drill hammer comprising a casing having externally threaded distal end, and a chuck having internal threads threadedly connectable to the distal end of the casing. The down-the-hole drill hammer further comprising a drill bit having a head and a shank extending proximally from the head, and a bit retaining ring between the casing and the chuck for releasably retaining the drill bit.

Abstract: A down-the-hole drill hammer including a drill bit about a distal end of the hammer and a piston for percussively contacting the drill bit. The drill hammer further includes a valve assembly for supplying and exhausting drive fluid to and from the piston, the valve assembly having a valve housing in fluid communication with drive fluid supply ports, drive ports and exhaust ports, and a control valve movable within the valve housing and in fluid communication with the valve housing. The drill hammer further includes a piston follower valve unconnected to the piston movable within the control valve for controlling positioning of the control valve and pressures applied to the piston via the drive ports and exhaust ports.

Abstract: A flow diversion sub for a down-the-hole drill comprising a housing assembly that includes a housing body, a cap extending from the housing body, and a drive shaft having an upper central blind hole and a lower central blind hole spaced from the upper central blind hole, wherein the drive shaft is received within the housing assembly. In operation, one of the housing assembly and drive shaft moves between a first position and a second position relative to the other of the housing assembly and drive shaft. In the first position the upper central blind hole is in fluid communication with the lower central blind hole, and in the second position the upper central blind hole is blocked from being in fluid communication with the lower central blind hole.

Abstract: A down-the-hole drill hammer is provided that includes a housing, a drill bit proximate a distal end of the housing, and a roller bearing assembly. The roller bearing assembly circumscribes the drill bit. The roller bearing assembly includes a race and a plurality of rollers. The plurality of rollers are operatively engaged with the race.

Abstract: A down-the-hole drill hammer for optimizing air consumption. The down-the-hole drill hammer includes a housing, a backhead connected to the housing, and a pressure control check valve assembly mounted within the housing. The pressure control check valve assembly includes a first check valve and a second check valve. The first check valve controls a flow of working fluid through the backhead. The second check valve is mounted to the first check valve and controls a flow of working fluid through the first check valve.

Abstract: A flow diversion sub for a down-the-hole drill comprising a housing assembly that includes a housing body, a cap extending from the housing body, and a drive shaft having an upper central blind hole and a lower central blind hole spaced from the upper central blind hole, wherein the drive shaft is received within the housing assembly. In operation, one of the housing assembly and drive shaft moves between a first position and a second position relative to the other of the housing assembly and drive shaft. In the first position the upper central blind hole is in fluid communication with the lower central blind hole, and in the second position the upper central blind hole is blocked from being in fluid communication with the lower central blind hole.

Abstract: A down-the-hole drill hammer is provided that includes a housing, a drill bit, a piston, a roller ramp clutch and a coupler. The DHD is configured to have a bit-piston-clutch-casing torque circuit which concurrently rotates the piston and drill bit. The drill bit is positioned proximate a distal end of the housing. The piston is configured to reciprocally move within the housing along an axial direction. The piston includes a helical spline and an axial spline on a surface of the piston. The roller ramp clutch circumscribes and engages the piston. The coupler circumscribes and engages the piston and drill bit.

Abstract: A down-the-hole drill hammer is provided that includes a housing, a drill bit proximate a distal end of the housing, and a roller bearing assembly. The roller bearing assembly circumscribes the drill bit. The roller bearing assembly includes a race and a plurality of rollers. The plurality of rollers are operatively engaged with the race.

Abstract: A non-rotational drill bit for a down-the-hole drill hammer is provided that includes a head and a shank extending from the head. The head includes a plurality of axisymmetric cutting members about its working face. The drill bit also includes a porting system that includes a central through hole, an air inlet port, an exhaust outlet port and a central exhaust port for exhausting air from an interior of the drill hammer and for clearing drilling debris from the face of the drill bit.

Abstract: A drill bit for a down-the-hole drill hammer is provided that includes a head and a shank extending from the head. The head includes a plurality of non-concentrically or spirally arranged cutting members about its working face. The non-concentric or spiral arrangement of the cutting members in the drill bit and their overlapping cutting paths during rotation of the drill bit reduces the presence of concentric grooves or valleys being cut into the earthen terrain impacted by the bit thereby resulting in more complete cutting coverage.

Abstract: A down-the-hole drill hammer is provided that includes a housing, a drill bit, a piston, a roller ramp clutch and a coupler. The DHD is configured to have a bit-piston-clutch-casing torque circuit which concurrently rotates the piston and drill bit. The drill bit is positioned proximate a distal end of the housing. The piston is configured to reciprocally move within the housing along an axial direction. The piston includes a helical spline and an axial spline on a surface of the piston. The roller ramp clutch circumscribes and engages the piston. The coupler circumscribes and engages the piston and drill bit.

Abstract: A drill bit for a down-the-hole drill hammer is provided that includes a head and a shank extending from the head. The head includes a plurality of non-concentrically or spirally arranged cutting members about its working face. The non-concentric or spiral arrangement of the cutting members in the drill bit and their overlapping cutting paths during rotation of the drill bit reduces the presence of concentric grooves or valleys being cut into the earthen terrain impacted by the bit thereby resulting in more complete cutting coverage.

Abstract: A down-the-hole drill hammer is provided that includes a housing, a piston mounted within the housing, a drill bit mounted below the housing, and a drive coupling operatively engaged with the housing and drill bit. The drive coupling can be configured with a plurality of lugs circumferentially disposed about the drill bit and coupled with the casing for providing rotation thereof. Alternatively, the drive coupling can be configured with segmented lugs configured to circumscribe the drill bit, or as a cylindrical chuck formed out of arch-shaped chuck segments which radially assemble onto the shank of the drill bit.

Abstract: A down-the-hole drill hammer for optimizing air consumption. The down-the-hole drill hammer includes a housing, a backhead connected to the housing, and a pressure control check valve assembly mounted within the housing. The pressure control check valve assembly includes a first check valve and a second check valve. The first check valve controls a flow of working fluid through the backhead. The second check valve is mounted to the first check valve and controls a flow of working fluid through the first check valve.