IPC Main Group
E21F 13/00 Transport specially adapted to underground conditions
Introduced: September 1968
Last revised: January 2006
Classification Context
- Section:
- FIXED CONSTRUCTIONS
- Class:
- EARTH OR ROCK DRILLING; MINING
- Subclass:
- SAFETY DEVICES, TRANSPORT, FILLING-UP, RESCUE, VENTILATION, OR DRAINAGE IN OR OF MINES OR TUNNELS
Related Keywords
ANCHORING of mining conveyersRAILWAY(S),RAILROAD(S) adapted to use in minesTRANSPORT in mines
5 direct subcodes
Child Classifications
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- E21F 13/02 in galleries
- E21F 13/04 in gravity inclines; in staple or inclined shafts
- E21F 13/06 at or adjacent to the working face
- E21F 13/08 Shifting conveyors or other transport devices from one location at the working face to another
- E21F 13/1 Anchorings for conveyors
Top Applicants
Top 10 applicants by patent filingsfor class E21, 2013–2023, worldwide · Source: EPO PATSTAT
- HALLIBURTON ENERGY SERVICES GROUP US 26,607
- PETROCHINA COMPANY 14,382
- SINOPEC (CHINA PETROCHEMICAL CORPORATION) 10,137
- CNPC (CHINA NATIONAL PETROLEUM CORPORATION) 6,517
- BAKER HUGHES US 6,269
- SCHLUMBERGER TECHNOLOGY US 5,929
- SAUDI ARABIAN OIL COMPANY SA 5,880
- SOUTHWEST PETROLEUM UNIVERSITY 4,477
- CHINA UNIVERSITY OF MINING AND TECHNOLOGY 4,357
- SCHLUMBERGER TECHNOLOGY NL 4,219