IPC Subgroup
E21B 1/04 Devices for reversing the movement of the rod or cable at the surface
Introduced: September 1968
Last revised: January 2006
Full Title
Percussion drilling > Surface drives for drop hammers, e.g. with a cable > Devices for reversing the movement of the rod or cable at the surface
Classification Context
- Section:
- FIXED CONSTRUCTIONS
- Class:
- EARTH OR ROCK DRILLING; MINING
- Subclass:
- EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS