Activated earth drill

Air-operated drilling machine or rotary-percussive action

Annular air-hammer apparatus for drilling holes

Annular drilling hammer

Apparatus and method for a hydraulic diaphragm downhole mud...

Apparatus and process for drilling underground arcuate paths uti

Apparatus for applying pressure to fluid seals

Apparatus for drilling a curved borehole

Apparatus for drilling a curved borehole

Apparatus for drilling oil and gas wells and a torque arrestor a

Apparatus for preventing separation of a down-hole motor from a

Apparatus for producing an upwardly directed drill hole

Apparatus for propulsion in elongated cavities

Apparatus for reducing hydro-static pressure at the drill bit

Apparatus for the removal of spoil when making trenches of great

Apparatus for transporting equipment through a conduit

Articulated coupling for use with a downhole drilling apparatus

Articulated tool for drilling oil, gas geothermal wells

Bearing assemblies, and bearing apparatuses and motor...

Bearing assemblies, and bearing apparatuses and motor...