IPC Main Group
E21F 17/00 Methods or devices for use in mines or tunnels, not covered elsewhere
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
power-supply in MINE(S)PIPE(S) networks in mines
5 direct subcodes
Child Classifications
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- E21F 17/02 Suspension devices for tubes or the like, e.g. for ventilating ducts
- E21F 17/04 Distributing means for power supply
- E21F 17/103 Dams, e.g. for ventilation
- E21F 17/16 Modification of mine passages or chambers for storage purposes, especially for liquids or gases
- E21F 17/18 Special adaptations of signalling or alarm devices
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