IPC Main Group
E21F 5/00 Means or methods for preventing, binding, depositing or removing dust; Preventing explosions or fires
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
compositions for laying DUST in minessafety devices in MINE(S)
6 direct subcodes
Child Classifications
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- E21F 5/02 by wetting or spraying
- E21F 5/08 Rock dusting; Depositing other protective substances
- E21F 5/14 Fluid barriers or rock dusters made to work by, or at the same time as, shots or explosions
- E21F 5/16 Layers of hygroscopic or other salts deposited on floors, walls, or the like, for binding dust; Deposition of such layers
- E21F 5/18 Impregnating walls, or the like, with liquids for binding dust
- E21F 5/2 Drawing-off or depositing dust
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