IPC Main Group
E21F 15/00 Methods or devices for placing filling-up materials in underground workings
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
Filing statistics
IPC E21F 15/00 belongs to the parent subclass E21F, which recorded 72,973 patent applications worldwide between 2013 and 2023. Annual filings grew from 3,134 in 2013 to 11,338 in 2023 (+262%). The most active applicants in class E21 are HALLIBURTON ENERGY SERVICES GROUP (26,607 applications), PETROCHINA COMPANY (14,382 applications) and SINOPEC (CHINA PETROCHEMICAL CORPORATION) (10,137 applications).
Source: EPO PATSTAT, worldwide filings
Related Keywords
FILLING UP in minesSTOWAGE in mines [= filling-up]
3 direct subcodes
Child Classifications
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- E21F 15/02 Supporting means, e.g. shuttering, for filling-up materials
- E21F 15/06 Filling-up mechanically
- E21F 15/08 Filling-up hydraulically or pneumatically
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