IPC Subgroup
E21D 15/52 Extensible units located above or below standard props
Introduced: September 1968
Last revised: January 2006
Full Title
Props; Chocks > Component parts or details of props > Extensible units located above or below standard props
Classification Context
- Section:
- FIXED CONSTRUCTIONS
- Class:
- EARTH OR ROCK DRILLING; MINING
- Subclass:
- SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS