Described herein are multi-tool boring systems and methods of operating such systems for tunnel boring and/or underground pipe installation. A multi-tool boring system is specially configured for fast installation and replacement of various tools, such as a pneumatic rammer and a hydraulic drive, enabling different operating modes of the system, e.g., pilot tube installation, auger boring, pipe ramming, pilot pullback boring, static pipe bursting, and non-contact boring. In some examples, a multi-tool boring system comprises a track assembly, a jacking frame slidably supported on the track assembly, and an impact plate assembly, which is attached to the jacking frame and comprises an impact plate and shock absorbers between the impact plate and the jacking frame. The impact plate comprises an impact plate opening configured to engage and support a pneumatic rammer. The rammer can be replaced with a hydraulic drive with a shaft protruding through the opening.

A fluid pressure driven, high frequency percussion hammer for drilling in hard formations is presented. The hammer piston (20) of the percussion hammer has a relatively large and longitudinally extending bore (41) that provides minimal flow resistance for a drilling fluid flowing through the bore (41) during the return stroke of the hammer piston (20). The bore (41) is closeable in the upstream direction by a valve plug (23) that follows the hammer piston (20) during the stroke. The valve plug (23) is controlled by a relatively long and slender valve stem (49) that is mechanically able to stop the valve plug (23) by approximately 75% of the full stroke length of the hammer piston (20) and separates the plug (23) from a seat ring (40). Thus the bore (41) opens up such that the bore fluid can flow there trough, and the inherent tension spring properties of the valve stem (49) returns the valve plug (23) so rapid that it will be good through flow during return of the hammer piston (20).

Described herein are multi-tool boring systems and methods of operating such systems for tunnel boring and/or underground pipe installation. A multi-tool boring system is specially configured for fast installation and replacement of various tools, such as a pneumatic rammer and a hydraulic drive, enabling different operating modes of the system, e.g., pilot tube installation, auger boring, pipe ramming, pilot pullback boring, static pipe bursting, and non-contact boring. In some examples, a multi-tool boring system comprises a track assembly, a jacking frame slidably supported on the track assembly, and an impact plate assembly, which is attached to the jacking frame and comprises an impact plate and shock absorbers between the impact plate and the jacking frame. The impact plate comprises an impact plate opening configured to engage and support a pneumatic rammer. The rammer can be replaced with a hydraulic drive with a shaft protruding through the opening.

Described herein are multi-tool boring systems and methods of operating such systems for tunnel boring and/or underground pipe installation. A multi-tool boring system is specially configured for fast installation and replacement of various tools, such as a pneumatic rammer and a hydraulic drive, enabling different operating modes of the system, e.g., pilot tube installation, auger boring, pipe ramming, pilot pullback boring, static pipe bursting, and non-contact boring. In some examples, a multi-tool boring system comprises a track assembly, a jacking frame slidably supported on the track assembly, and an impact plate assembly, which is attached to the jacking frame and comprises an impact plate and shock absorbers between the impact plate and the jacking frame. The impact plate comprises an impact plate opening configured to engage and support a pneumatic rammer. The rammer can be replaced with a hydraulic drive with a shaft protruding through the opening.

A method and a mandrel for forming a cavity at a target location. The mandrel may include a main drilling shaft, a plurality of T-shaped elements, a hollow-cylindrical-shaped element, and a plurality of parallelepiped-shaped stiffener plates. The main drilling shaft may include a hammer insertion part positioned at a first end of the main drilling shaft, a bore head positioned at a second end of the main drilling shaft, and a medium part positioned between the hammer insertion part and the bore head. The plurality of T-shaped elements may be mounted adjacently around the medium part in a way such that forming a closed octagonal from a top-view of the mandrel. A first size of a first cross-section at a first location from a top-view of the plurality of T-shaped elements around the medium part may be larger than a second size of a second cross-section at a second location from the top-view.

A downhole sensing device deployment control apparatus (10) includes means to control speed of the sensing device progressing within a borehole associated with a drilling operation. A mechanical, electrically powered and/or hydro-dynamic drag/damping means/device (12) can be provided as part of the control apparatus to control speed of deployment down the borehole. The drag device (12) can have a plurality of wheels or rollers to contact an internal bore of an inner pipe of a drill string. Rotation control means (24), (26) can be provided to control an amount of rotation and/or direction of rotation of the wheels or rollers relative to travel of the sensing device within the borehole. Valving (60) can be provided. A two stage (dual) flow/pressure control valve (100) can be provided. A sensing device (release 216) and downhole position latch (202) can be provided. The sensing device can be pumped into the borehole, such as by compressed air.

Herein a bolt (2) comprising an elongated body (4) with a central axis (C) is described. The elongated body (4) is in a first end (6) provided with a first thread (8) and in a second end (10) with a second thread (12). An intermediate part (14) of the elongated body (4) is provided with a collar (16). The collar (16) is provided with at least one first flat surface (18), which first flat surface (18) extends substantially in parallel with the central axis (C). Further, a rock drill comprising housing parts held together by at least one bolt (2) is described.

A pipe section for coupling to one or more pipe sections in order to form an elongate tubular. The pipe section has an optical fiber extending along a longitudinal axis of the pipe section and a waveguide disposed near one end of the pipe section and is in optical communication with the optical fiber to guide light in a plane substantially perpendicular to the longitudinal axis.

A force stacking assembly for use with an earth boring system that includes a series of actuators that each generate a force, and that are arranged to create a combined force that is cumulative of all of the actuators. The actuators include members that react in response to an applied stimulus, such as from an electrical current or magnetic field. The members are arranged in series in a hollow housing, planar bulkheads are transversely mounted in the housing. Each of the members have an end axially abutting a corresponding bulkhead. Ends of each member distal from it corresponding bulkhead couple to a ram member, that in turn couples to a drill bit. Energizing the members causes each to exert a force against the ram member, which is transferred to the bit.

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.