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 preventing separation of a down-hole motor from a

Articulated coupling for use with a downhole drilling apparatus

Bearing assemblies, and bearing apparatuses and motor...

Bearing assemblies, and bearing apparatuses and motor...

Bearing system for a downhole motor

Bearing system for a downhole motor

Bottom hole motor for driving rock-breaking tool

Bottom-hole multistart screw motor

Circulation sub for in-hole hydraulic motors

Core drilling tool for boreholes in rock

Device for producing boreholes in coal or the like

Device for producing boreholes in coal or the like

Direct bit drive for deep drilling tools

Direct drive for deep-well drilling

Down hole drilling motor with pressure balanced bearing seals