A fluid pulse apparatus for down hole drilling having a turbine assembly actuated by a flow of drilling fluid. The apparatus has a narrowed fluid flow section that cooperates with a piston that moves between an open a fluid flow restricting position. The apparatus has a turbine assembly that rotates in response to a flow of drilling fluid. The turbine apparatus has upper and lower cam followers that cooperate with fixed cam surface such that rotation of the turbine assembly and cam action between the cam followers and the fixed cam surface causes the turbine assembly to reciprocate axially. The piston is fixed to either of the upper or the lower turbine surface such that as the turbine assembly reciprocates axially, the piston moves between the open and the flow restricting positions to create a pulsed fluid flow.

A down the hole rock drilling machine and a method of drilling rock. The drilling machine comprises a casing (15) inside which is a control sleeve (20). A reciprocating piston (19) is arranged to move inside the control sleeve and control feeding and discharging of working chambers (20, 21). Between the control sleeve and an inner surface of the casing are all the fluid passages (28, 29, 30, 31) needed for fluid routing. The piston opens and closes transverse openings and controls the work cycle.

A down the hole rock drilling machine and a method of drilling rock. The drilling machine comprises a casing (15) inside which is a control sleeve (20). A reciprocating piston (19) is arranged to move inside the control sleeve and control feeding and discharging of working chambers (20, 21). Between the control sleeve and an inner surface of the casing are all the fluid passages (28, 29, 30, 31) needed for fluid routing. The piston opens and closes transverse openings and controls the work cycle.

A method for maintaining a penetration rate of a drilling operation, where the drilling operation is carried out by a drilling rig having a hammer drill apparatus. A reference penetration rate for the hammer drill bit is chosen. A starting depth of cut is computed from the reference penetration rate, the measured hammer frequency, and the drill bit parameters. The system measures the actual penetration rate of the drill bit and computes an actual depth of cut. From the actual depth of cut a target bit rotation speed is computed. The target rotation speed is compared to the actual rotation speed, and the rotation speed is adjusted up or down to set the bit rotation speed at a value that will maintain the target rotation speed, notwithstanding changes in hammer frequency or ground conditions.

A method for maintaining a penetration rate of a drilling operation, where the drilling operation is carried out by a drilling rig having a hammer drill apparatus. A reference penetration rate for the hammer drill bit is chosen. A starting depth of cut is computed from the reference penetration rate, the measured hammer frequency, and the drill bit parameters. The system measures the actual penetration rate of the drill bit and computes an actual depth of cut. From the actual depth of cut a target bit rotation speed is computed. The target rotation speed is compared to the actual rotation speed, and the rotation speed is adjusted up or down to set the bit rotation speed at a value that will maintain the target rotation speed, notwithstanding changes in hammer frequency or ground conditions.

A down-the-hole drill hammer is provided that includes a housing, a drill bit proximate a distal end of the housing, and a roller bearing assembly. The roller bearing assembly circumscribes the drill bit. The roller bearing assembly includes a race and a plurality of rollers. The plurality of rollers are operatively engaged with the race.

A down-the-hole drill hammer is provided that includes a housing, a drill bit proximate a distal end of the housing, and a roller bearing assembly. The roller bearing assembly circumscribes the drill bit. The roller bearing assembly includes a race and a plurality of rollers. The plurality of rollers are operatively engaged with the race.

A hydraulic percussion device comprising a piston mounted for reciprocal motion within a cylinder to impact a percussion bit and a control valve to control reciprocation of the piston. A valve pilot line is arranged to switch the control valve based on the position of the piston within the cylinder, wherein the valve pilot line is alternately connected, by the reciprocal movement of the piston, to high and low pressure lines (P, T) via an undercut in the piston. The undercut is located at a portion of the piston having a diameter less than the maximum sealing diameter of the piston.

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).

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).