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.

A flushing system in a drill bit is disclosed. The drill bit includes a body that defines the flushing system. The flushing system includes an inlet to facilitate supply of pressurized fluids into the bore hole. A cutting surface of the drill bit is provided with a main opening that defines a main passageway in communication with the inlet. A peripheral surface of the drill bit is provided with a secondary opening that defines a secondary passageway in communication with the inlet. The secondary passageway is disposed at an angle from a horizontal reference plane. The horizontal reference plane is defined between the inlet and the origin of the main passageway and is perpendicular to a central longitudinal axis of the body of the drill bit. An origin of the secondary passageway is at a distance from the origin of main passageway.

The present invention relates to a drilling device. The device comprises at least one drill rod, the or each drill rod having a first cylindrical wall defining an elongate chamber for receiving a working fluid to form a fluid column, the length of the fluid column being equal to a total length of the elongate chambers of the or each drill rod. The device also comprises a displacement excitation device arranged at a proximal end of the fluid column and configured to excite the fluid column to cause the working fluid in the fluid column to oscillate, wherein the excitation device is configured to excite the fluid column at an excitation frequency at or within 10% of a natural frequency of the fluid column determined based on the fluid column having a fixed boundary condition at a proximal end thereof. The device further comprises a tool piston moveably mounted at a distal end of the fluid column and a drilling tool connected to the tool piston such that the oscillation of the working fluid in the fluid column imparts an oscillating force to the drilling tool.

The invention relates to a rotary drilling tool and to a method for producing a borehole in the ground, having a base body, a removal device which has at least one hammer unit which comprises a hammer element driven in axially reversing manner, and a discharge line for discharging removed ground material and drilling suspension. According to the invention it is provided that a pumping device is arranged on the base body along the discharge line, and that the pumping device is configured for pumping off the removed ground material with drilling suspension through the discharge line.

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 ground drilling device with a drivetrain for rotating a drill string, wherein at least one section of the drivetrain is configured to form a channel between a force transmission element of the drivetrain and the drill string, wherein the channel projects through the force transmission element and the force transmission element may be driven radially in the drivetrain.

The invention relates to a rotary drilling tool and to a method for producing a borehole in the ground, having a base body, a removal device which has at least one hammer unit which comprises a hammer element driven in axially reversing manner, and a discharge line for discharging removed ground material and drilling suspension. According to the invention it is provided that a pumping device is arranged on the base body along the discharge line, and that the pumping device is configured for pumping off the removed ground material with drilling suspension through the discharge line.

Provided is a method for controlling a resonance enhanced rotary drill comprising a drilling module and a control system for controlling one or more drilling parameters of the drilling module, which method comprises: (a) employing one or more initial characteristics of the material being drilled, and/or one or more initial drilling parameters to control the drilling module; (b) measuring one or more current drilling parameters to obtain one or more measured drilling parameters; (c) employing the one or more measured drilling parameters as an input in the control system, in order to obtain an output from the control system, which output comprises one or more calculated characteristics of the material being drilled; (d) employing the one or more calculated characteristics of the material being drilled, and/or the one or more measured drilling parameters, as an input in the control system, in order to obtain an output from the control system, which output comprises one or more calculated drilling parameters; (e) optionally applying the one or more calculated drilling parameters to the drilling module; (f) optionally repeating steps (b), (c) (d) and (e).

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.