The present invention relates to a fluid-operated percussion drill tool comprising an outer wear sleeve comprising a substantially cylindrical wall and having inner and outer surfaces. The tool also comprises a percussion bit having a head portion and a bit retaining portion and located at a forward end of the outer wear sleeve. The tool further comprises a sliding piston mounted for reciprocating movement within the outer wear sleeve to strike the percussion bit. The tool also includes a drive ring having a substantially cylindrical wall and comprising connection means adapted for connecting the drive ring to a drive means of the fluid-operated percussion drill tool. At least one flushing channel provides a fluid path to the cutting face of the bit for a flushing medium. A first portion of the at least one flushing channel extends longitudinally within the wall of the wear sleeve, a second portion of the at least one flushing channel extends longitudinally within the wall of the drive ring and a third portion of the at least one flushing channel extends through the head portion of the percussion bit to the cutting face of the bit.

The present invention relates to a fluid-operated percussion drill tool comprising an outer wear sleeve comprising a substantially cylindrical wall and having inner and outer surfaces. The tool also comprises a percussion bit having a head portion and a bit retaining portion and located at a forward end of the outer wear sleeve. The tool further comprises a sliding piston mounted for reciprocating movement within the outer wear sleeve to strike the percussion bit. The tool also includes a drive ring having a substantially cylindrical wall and comprising connection means adapted for connecting the drive ring to a drive means of the fluid-operated percussion drill tool. At least one flushing channel provides a fluid path to the cutting face of the bit for a flushing medium. A first portion of the at least one flushing channel extends longitudinally within the wall of the wear sleeve, a second portion of the at least one flushing channel extends longitudinally within the wall of the drive ring and a third portion of the at least one flushing channel extends through the head portion of the percussion bit to the cutting face of the bit.

The present invention is directed to a dynamic seal tube for use in pressurized fluid-driven down hole hammer drills. The dynamic seal tube is a tube that slides within the bore of the piston and the anvil portion of the drill bit and co-operatively acts to release different volumes of pressurized fluid from the lower chamber when the piston is in different predetermined positions.

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.

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.

A down-the-hole hammer includes a barrel having a longitudinal axis and defining a proximal chamber and a distal chamber, a piston slidable within the barrel between the proximal chamber and the distal chamber, and a flow control valve including a valve member slidable within the barrel along the longitudinal axis to control airflow through the piston. In a first position of the valve member, the valve member allows air flow from a proximal end of the barrel through the piston and into the distal chamber. In a second position of the valve member, the valve member allows air flow around the valve member and into the proximal chamber.

A down-the-hole hammer includes a barrel having a longitudinal axis and defining a proximal chamber and a distal chamber, a piston slidable within the barrel between the proximal chamber and the distal chamber, and a flow control valve including a valve member slidable within the barrel along the longitudinal axis to control airflow through the piston. In a first position of the valve member, the valve member allows air flow from a proximal end of the barrel through the piston and into the distal chamber. In a second position of the valve member, the valve member allows air flow around the valve member and into the proximal chamber.

A down-the-hole hammer includes a barrel having a longitudinal axis and defining a middle chamber and a bottom chamber, a piston defining a top chamber and slidable within the barrel between the middle chamber and the bottom chamber, a control tube having a distal port, and an air distributor having a first distal port and a second distal port. The control tube is indexable between a plurality of rotational positions to adjust which of the first distal port and the second distal port of the air distributor is aligned with the distal port of the control tube.

A down-the-hole hammer includes a barrel having a longitudinal axis and defining a proximal chamber and a distal chamber, a piston slidable within the barrel between the proximal chamber and the distal chamber, and a flow control valve including a valve member slidable within the barrel along the longitudinal axis to control airflow through the piston. In a first position of the valve member, the valve member allows air flow from a proximal end of the barrel through the piston and into the distal chamber. In a second position of the valve member, the valve member allows air flow around the valve member and into the proximal chamber.

A down-the-hole hammer includes a barrel having a longitudinal axis and defining a proximal chamber and a distal chamber, a piston slidable within the barrel between the proximal chamber and the distal chamber, and a flow control valve including a valve member slidable within the barrel along the longitudinal axis to control airflow through the piston. In a first position of the valve member, the valve member allows air flow from a proximal end of the barrel through the piston and into the distal chamber. In a second position of the valve member, the valve member allows air flow around the valve member and into the proximal chamber.