The hydraulic rotary-percussive hammer drill includes a body; a shank; a striking piston configured to hit the shank; a stop piston configured to position the shank in a predetermined balanced position, the body and the stop piston delimiting a first control chamber permanently connected to a high-pressure fluid feed-in conduit and configured to urge the stop piston forwards, and a second control chamber configured to urge the stop piston forwards. The hydraulic rotary-percussive hammer drill comprises a fluidic communication channel opening into the second control chamber, configured to supply the second control chamber with high-pressure fluid and provided with a calibrated orifice.

The hydraulic rotary-percussive hammer drill includes a body; a shank; a striking piston configured to hit the shank; a stop piston configured to position the shank in a predetermined balanced position, the body and the stop piston delimiting a first control chamber permanently connected to a high-pressure fluid feed-in conduit and configured to urge the stop piston forwards, and a second control chamber configured to urge the stop piston forwards. The hydraulic rotary-percussive hammer drill comprises a fluidic communication channel opening into the second control chamber, configured to supply the second control chamber with high-pressure fluid and provided with a calibrated orifice.

The hydraulic rotary-percussive hammer drill includes a fluid injection portion including a fluid feed-in inlet and an annular inner groove fluidly connected to the fluid feed-in inlet; a shank including a fluid injection conduit fluidly connected to the annular inner groove; front and rear main sealing gaskets disposed on either side of the annular inner groove and configured to cooperate with a first shank portion of the shank; a rear backup sealing gasket located at the rear of the rear main sealing gasket and configured to cooperate with a second shank portion of the shank; a leakage passage defined between the shank and the fluid injection portion; pressure drop generation means configured to generate pressure drops in the leakage passage when a leakage flow flows in the leakage passage.

Cutters for a downhole drill bit can be formed by providing a catalyst-free synthesized polycrystalline diamond (PCD) having a cross-sectional dimension of at least 8 millimeters; providing a substrate comprising tungsten carbide; and attaching the synthesized PCD to the substrate comprising tungsten carbide to form a PDC cutter.

Cutters for a downhole drill bit can be formed by providing a catalyst-free synthesized polycrystalline diamond (PCD) having a cross-sectional dimension of at least 8 millimeters; providing a substrate comprising tungsten carbide; and attaching the synthesized PCD to the substrate comprising tungsten carbide to form a PDC cutter.

A percussion drilling device for drilling in earth includes at least one housing section for a main piston, and a ring insert arranged in the housing section in front of the main piston so that the ring insert transmits at least part of the energy of the main piston onto the housing. The ring insert is attached to the housing by a shrink-fit connection.

A percussion drilling device for drilling in earth includes at least one housing section for a main piston, and a ring insert arranged in the housing section in front of the main piston so that the ring insert transmits at least part of the energy of the main piston onto the housing. The ring insert is attached to the housing by a shrink-fit connection.

A hydraulic hammer assembly is provided. The hydraulic hammer assembly includes a housing and a piston is arranged for reciprocating movement along a longitudinal axis within the housing. A head disposed along the longitudinal axis on an end of the housing and defines a chamber for holding a pressurized gas. The hydraulic hammer assembly further includes a locking mechanism to lock the head on the housing. The locking mechanism includes at least one first flange extending radially from the end of the housing and at least one second flange extending radially from the head, wherein the head is retained on the housing by blocking axial movement of the second flange against the first flange when in a locked position.

A percussion piston for a rock drill machine having a pilot cylinder, a distributor and a pressure medium includes a control edge configurable to cause a change in the position of the distributor in a direction parallel to the axial direction of the percussion piston as the percussion piston moves in the impact direction (A) in relation to the pilot cylinder. The control edge of the percussion piston includes at least one notch provided on the outer periphery of the control edge and arranged to cause a start of a state change for the distributor before the control edge of the percussion piston passes by a corresponding control edge provided on the distributor or pilot cylinder.

A breakout wrench assembly for a drill rig includes two support shafts. Each of the two support shafts is configured to extend in a direction relative to a drill pipe on a drill rig. The breakout wrench assembly also includes a carrier coupled to the two support shafts. The carrier is movable linearly along the two support shafts. The breakout wrench assembly also includes a breakout wrench pivotally coupled to the carrier or to one of the two support shafts. The breakout wrench includes a first end coupled to the carrier or to one of the two support shafts, and a second, opposite end configured to engage the drill pipe.