Systems and methods for installing pipe underground are disclosed. The system includes a pneumatic rammer configured to provide a percussive force to a section of pipe. The system also includes a main jacking frame coupled to the pneumatic rammer, the main jacking frame including a surface for contacting the section of pipe. The system also includes one or more hydraulic jacks coupled to the main jacking frame and configured to provide a hydraulic force to the section of pipe. The system also includes a set of tracks coupled to the main jacking frame, the set of tracks permitting the main jacking frame to slide in a longitudinal direction. An independently displaceable soil-clearing system can be included to clear dirt coming inside the pipe during the installation and add extra jacking force as needed.

A valve of a hydraulically striking device having a housing, the housing comprising a moving member being seated inside the housing to move in a reciprocating manner by means of a hydraulic fluid. The moving member has an inner space, the valve has a return space and a pressure space provided, in the axial direction, at a distance from one another on the inner surface of the housing facing the moving member, wherein the rest of the inner surface of the housing in the same axial positions of the return space and the pressure space forms guide surfaces that are concentric with the moving member and against the moving member for centering the moving member.

The present invention relates to a method for determining state of at least one joint of a drill string of a drill rig, the drill rig including a percussion device for inducing shock waves into the drill string, and a sensor for sensing stress waves in the drill string caused by impacts of the percussive device, the method comprising, when a stress wave is induced into the drill string by the percussive device: determining a representation of the incident stress wave caused by the percussive device; determining a representation of a reflected wave representing a reflection of the incident stress; estimating a stiffness of the at least one joint by estimating a force exerted on the at least one joint by the incident wave.

The present invention relates to a method for determining state of at least one joint of a drill string of a drill rig, the drill rig including a percussion device for inducing shock waves into the drill string, and a sensor for sensing stress waves in the drill string caused by impacts of the percussive device, the method comprising, when a stress wave is induced into the drill string by the percussive device: determining a representation of the incident stress wave caused by the percussive device; determining a representation of a reflected wave representing a reflection of the incident stress; estimating a stiffness of the at least one joint by estimating a force exerted on the at least one joint by the incident wave.

Damping device for a percussion device of a hydraulic rock drilling machine (1) with a striking direction (R), including a damping piston (5) for action in an axial direction against a tool, wherein the damping piston (5) exhibits a first piston portion (6), which is received in a first damping chamber (7) and a second piston portion (8), which is received in a second damping chamber (9). In operation, in a normal striking position of said percussion device, the damping piston (5) is set against a fixed stop (19) against movements in the striking direction. A damping slot (10) is established between the first (7) and the second (9) damping chamber in all axial positions of the damping pistons, and the first damping chamber (7) is pressurized with a hydraulic pressure. The invention also concerns a percussion device and a rock drilling machine.

Damping device for a percussion device of a hydraulic rock drilling machine (1) with a striking direction (R), including a damping piston (5) for action in an axial direction against a tool, wherein the damping piston (5) exhibits a first piston portion (6), which is received in a first damping chamber (7) and a second piston portion (8), which is received in a second damping chamber (9). In operation, in a normal striking position of said percussion device, the damping piston (5) is set against a fixed stop (19) against movements in the striking direction. A damping slot (10) is established between the first (7) and the second (9) damping chamber in all axial positions of the damping pistons, and the first damping chamber (7) is pressurized with a hydraulic pressure. The invention also concerns a percussion device and a rock drilling machine.

A motor assembly is disclosed that includes a vane motor coupled to an output shaft by a drive section. The drive section includes hammers that engage the output shaft to provide improved torque.

A drilling system includes a control system that monitors operating parameters so as to protect the drilling machine from damage and increases drilling operation efficiency. A method of using a hydraulic system of a percussive drill as a sensing system includes sensing a drill bit blow-out event by measuring changes in the operating hydraulic fluid pressure in the hydraulic system used to operate the percussive drill.

Systems and methods for installing pipe underground are disclosed. The system includes a pneumatic rammer configured to provide a percussive force to a section of pipe. The system also includes a main jacking frame coupled to the pneumatic rammer, the main jacking frame including a surface for contacting the section of pipe. The system also includes one or more hydraulic jacks coupled to the main jacking frame and configured to provide a hydraulic force to the section of pipe. The system also includes a set of tracks coupled to the main jacking frame, the set of tracks permitting the main jacking frame to slide in a longitudinal direction. An independently displaceable soil-clearing system can be included to clear dirt coming inside the pipe during the installation and add extra jacking force as needed.

A hydraulic hammering device is capable of sufficiently transmitting blow energy to bedrock while further strengthening cushioning action and suppressing damage to equipment. The device includes a pushing piston disposed behind a transmission member and having a smaller propulsive force than that of a main body, a damping piston positioned behind the pushing piston to slide reciprocally forwards and backwards and having a greater propulsive force than that of the main body, a direction-restrictor in a high-pressure circuit between pushing and damping chambers, to which hydraulic fluid is supplied for providing the pistons with propulsive forces, and a fluid supply source. The direction-restrictor restricts an outflow from the chambers side to the fluid supply source side while allowing fluid inflow from the fluid supply source side to the chambers and the pushing chamber sides. A throttle in a drain circuit discharges leaked fluid from a sliding contact location to a tank.