Abstract: An improved leading end assembly for a HDD percussion boring system comprises a sonde housing, a percussion hammer and a tilted-face slant bit. The sonde housing body comprises a bent engagement feature and a shoe aspect that creates an asymmetrical cross section of the sonde housing. The percussion hammer is connected to the sonde housing via the bent engagement feature which is configured to position the percussion hammer on an angle relative to a longitudinal axis of the sonde housing. The tilted-face slant bit comprises a front face facet that defines a plane that is tilted relative to a plane that is perpendicular to a longitudinal axis of the bit shaft. Advantageously, embodiments of the solution do not include a bent sub component. Rather, the shoe aspect, the bent engagement feature and the front face facet collectively form an effective bend angle (as opposed to a single, abrupt bend angle imposed by a bent sub in prior art solutions).

Abstract: A bidirectional cluster hammer reamer (“BCHR”) for use in a horizontal direction drilling system comprises a plurality of percussive hammers and bits arranged around a central drive rod. The central drive rod is translatable between a forward most position and a rear most position. The central drive rod is translated to the forward most position when the BCHR is being pulled through a previously drilled pilot channel. The central drive rod is translated to the rear most position when a reverse feed force is applied to the BCHR. When in the rear most position, the central drive rod cooperates with an air distribution assembly at the rear of the BCHR to expel a portion of a pressurized fluid to the exterior of the BCHR for clearing accreted debris.

Abstract: Disclosed is a hammer reamer comprising cutting wheels, a product-pulling feature, and a hammer component operable to deliver a percussive cycle of an internal piston component. Notably, an internal impact surface within the head of the hammer reamer is positioned relative to the piston component in the hammer consistent with a “sweet spot” position of a drill bit used in a pilot boring configuration. Unlike a slidably engaged drill bit, however, the internal impact surface in the hammer reamer is fixed in place so that the impact surface remains in the “sweet spot” of the piston stroke range. In this way, even though the hammer reamer is being pulled back through a bore while the drill string is being retracted, the hammer component may continue to deliver percussive blows to the hammer reamer head to introduce a vibratory force that contributes to the efficiency of the reaming process.

Abstract: A bidirectional cluster hammer reamer (“BCHR”) for use in a horizontal direction drilling system comprises a plurality of percussive hammers and bits arranged around a central drive rod. The central drive rod is translatable between a forward most position and a rear most position. The central drive rod is translated to the forward most position when the BCHR is being pulled through a previously drilled pilot channel. The central drive rod is translated to the rear most position when a reverse feed force is applied to the BCHR. When in the rear most position, the central drive rod cooperates with an air distribution assembly at the rear of the BCHR to expel a portion of a pressurized fluid to the exterior of the BCHR for clearing accreted debris.

Abstract: Disclosed is a hammer reamer comprising cutting wheels, a product-pulling feature, and a hammer component operable to deliver a percussive cycle of an internal piston component. Notably, an internal impact surface within the head of the hammer reamer is positioned relative to the piston component in the hammer consistent with a “sweet spot” position of a drill bit used in a pilot boring configuration. Unlike a slidably engaged drill bit, however, the internal impact surface in the hammer reamer is fixed in place so that the impact surface remains in the “sweet spot” of the piston stroke range. In this way, even though the hammer reamer is being pulled back through a bore while the drill string is being retracted, the hammer component may continue to deliver percussive blows to the hammer reamer head to introduce a vibratory force that contributes to the efficiency of the reaming process.

Abstract: Disclosed is a hammer reamer that comprises similar features to prior art reamers such as cutting wheels and a product-pulling feature. An exemplary hammer reamer, however, also includes a hammer component operable to deliver a percussive cycle of an internal piston component. Notably, an internal impact surface within the head of the hammer reamer is positioned relative to the piston component in the hammer consistent with a “sweet spot” position of a drill bit used in a pilot boring configuration. Unlike a slidably engaged drill bit, however, the internal impact surface in the hammer reamer is fixed in place so that the impact surface remains in the “sweet spot” of the piston stroke range. In this way, even though the hammer reamer is being pulled back through a bore while the drill string is being retracted, the hammer component may continue to deliver percussive blows to the hammer reamer head to introduce a vibratory force that contributes to the efficiency of the reaming process.

Abstract: An improved leading end assembly for a HDD percussion boring system comprises a sonde housing, a percussion hammer and a tilted-face slant bit. The sonde housing body comprises a bent engagement feature and a shoe aspect that creates an asymmetrical cross section of the sonde housing. The percussion hammer is connected to the sonde housing via the bent engagement feature which is configured to position the percussion hammer on an angle relative to a longitudinal axis of the sonde housing. The tilted-face slant bit comprises a front face facet that defines a plane that is tilted relative to a plane that is perpendicular to a longitudinal axis of the bit shaft. Advantageously, embodiments of the solution do not include a bent sub component. Rather, the shoe aspect, the bent engagement feature and the front face facet collectively form an effective bend angle (as opposed to a single, abrupt bend angle imposed by a bent sub in prior art solutions).