A system and method of fabricating a percussion tool that includes one or more surfaces modified using the ferritic nitrocarburization process. The percussion tool includes a piston positioned in sliding contact within a casing. The piston includes an inner wall and an outer wall, where the inner wall defines a passageway extending longitudinally therethrough. The outer wall is positioned in close fitting relationship with an internal surface of the casing. One or more surfaces of at least one of the casing's internal surface and/or the piston's outer wall are modified using the ferritic nitrocarburization process.

A circular cylindrical striker member 2 for a drilling machine adapted to transfer kinetic energy to an impulse receiving member 4. The striker member has a diameter d.sub.max, and includes a side surface 12 and an impulse surface (6). The striker member is adapted to transfer the kinetic energy to the impulse receiving member by a ring shaped active surface of the impulse surface, wherein the ring shaped active surface is concentric with regard to the cross section of the striker member, has a diameter d.sub.a, where d.sub.a<d.sub.max, and has a width w.sub.a that during the contact moment with the impulse receiving part is less than 0.2 d.sub.max.

A circular cylindrical striker member 2 for a drilling machine adapted to transfer kinetic energy to an impulse receiving member 4. The striker member has a diameter d.sub.max, and includes a side surface 12 and an impulse surface (6). The striker member is adapted to transfer the kinetic energy to the impulse receiving member by a ring shaped active surface of the impulse surface, wherein the ring shaped active surface is concentric with regard to the cross section of the striker member, has a diameter d.sub.a, where d.sub.a<d.sub.max, and has a width w.sub.a that during the contact moment with the impulse receiving part is less than 0.2 d.sub.max.

A rotary drill and a double-layer drilling rod mechanism are disclosed. A connecting rod (2) is provided in the rotary connecting sleeve (9), and the rotary connecting sleeve (9) is connected with the double-layer drilling rod mechanism (11). An impact drilling string (25) located by a guide bearing bush (26) is arranged in the outer rotary drilling pipe (28) of the double-layer drilling rod mechanism (11); a latch (24) for connecting the connecting rod (2) is arranged at the top of the inner impact drilling string (25); and an impact head (12) connected with the impact drilling string (25) is arranged in the drilling bit connecting sleeve (29). The drilling bit (13) below the impact head (12) is connected with the drilling bit connecting sleeve (29) by a front connector (30).

A rotary drill and a double-layer drilling rod mechanism are disclosed. A connecting rod (2) is provided in the rotary connecting sleeve (9), and the rotary connecting sleeve (9) is connected with the double-layer drilling rod mechanism (11). An impact drilling string (25) located by a guide bearing bush (26) is arranged in the outer rotary drilling pipe (28) of the double-layer drilling rod mechanism (11); a latch (24) for connecting the connecting rod (2) is arranged at the top of the inner impact drilling string (25); and an impact head (12) connected with the impact drilling string (25) is arranged in the drilling bit connecting sleeve (29). The drilling bit (13) below the impact head (12) is connected with the drilling bit connecting sleeve (29) by a front connector (30).

A hydraulic impact hammer having a hammer housing and a hydraulic piston. The hammer housing has means for attaching a hydraulic rotator converter which has a hydraulic rotator for rotating a drill bit for drilling holes on a surface while the drill bit receives pounding action from the piston. The drill bit has surface portions dimensioned to mate with bushing assembles and a cutout region to loosely engage with the locking mechanism in the hammer housing. After the holes are drilled, the converter is released from the hammer housing so as to allow a hammer tool with a larger diameter to be used for pounding over the holes. The hammer tool also has surface portions dimensioned to mate with the bushing assembles and a cutout region to engage with the locking mechanism so that the hammer tool can receive pounding action from the piston for pounding over the holes.

A rock drilling rig includes a drilling unit that is provided with hydraulically operated actuators, such as an impact device, a rotation device and a feed device. The impact device and the rotation device are connected to dedicated hydraulic circuits provided with dedicated supply and discharge lines and are controlled by means of dedicated control valves being on the a carrier of the rock drilling rig. The feed device is connected to a distributed hydraulic system, wherein several actuators are connected to a common hydraulic circuit (CHC) provided with one common supply line and one common discharge line and are controlled by several distributed valves. The distributed valve of the feed device is located at the drilling unit.

A rock drilling rig includes a drilling unit that is provided with hydraulically operated actuators, such as an impact device, a rotation device and a feed device. The impact device and the rotation device are connected to dedicated hydraulic circuits provided with dedicated supply and discharge lines and are controlled by means of dedicated control valves being on the a carrier of the rock drilling rig. The feed device is connected to a distributed hydraulic system, wherein several actuators are connected to a common hydraulic circuit (CHC) provided with one common supply line and one common discharge line and are controlled by several distributed valves. The distributed valve of the feed device is located at the drilling unit.

A system and method of fabricating a percussion tool that includes one or more surfaces modified using the ferritic nitrocarburization process. The percussion tool includes a piston positioned in sliding contact within a casing. The piston includes an inner wall and an outer wall, where the inner wall defines a passageway extending longitudinally therethrough. The outer wall is positioned in close fitting relationship with an internal surface of the casing. One or more surfaces of at least one of the casing's internal surface and/or the piston's outer wall are modified using the ferritic nitrocarburization process.

A system and method of fabricating a percussion tool that includes one or more surfaces modified using the ferritic nitrocarburization process. The percussion tool includes a piston positioned in sliding contact within a casing. The piston includes an inner wall and an outer wall, where the inner wall defines a passageway extending longitudinally therethrough. The outer wall is positioned in close fitting relationship with an internal surface of the casing. One or more surfaces of at least one of the casing's internal surface and/or the piston's outer wall are modified using the ferritic nitrocarburization process.