IPC Subgroup
E21D 1/06 with shaft-boring cutters
Introduced: September 1968
Last revised: January 2006
Full Title
Sinking shafts > mechanically > with shaft-boring cutters
Classification Context
- Section:
- FIXED CONSTRUCTIONS
- Class:
- EARTH OR ROCK DRILLING; MINING
- Subclass:
- SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS