Double acting hydraulic jar

Double acting hydraulic mechanism

Double acting jar

Double piston in-the-hole hydraulic hammer drill

Double-acting accelerator for use with hydraulic drilling jars

Down hole drills using spent driving fluid for flushing purposes

Down hole drills using spent driving fluid for flushing purposes

Down hole hammer

Down-hole hammer

Down-the-hole drill assembly

Down-the-hole drilling machine

Down-the-hole hammer and components for a down-the-hole...

Down-the-hole hammer and components for a down-the-hole...

Down-the-hole hammer drill having reverse circulation

Down-the-hole rock drill

Downhole jar apparatus for use in oil and gas wells

Downhole percussion tool

Drill bit assembly for fluid-operated percussion drill tools

Drill bit retainer for a down hole hammer assembly

Drill hammer assembly