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PCE
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DIFF Subgroup
E21C 41/16

Methods of underground mining (winning machines therefor E21C25/00 - E21C39/00); Layouts therefor

Introduced: January 1990

Title

Titles differ between systems:

IPC: Methods of underground mining; Layouts therefor

CPC: Methods of underground mining (winning machines therefor E21C25/00 - E21C39/00); Layouts therefor

Full Title

Full titles differ between systems:

IPC:

Methods of underground or surface mining; Layouts therefor > Methods of underground mining; Layouts therefor

CPC:

Methods of underground or surface mining (E21C45/00 takes precedence); Layouts therefor (for peat E21C49/00) > Methods of underground mining (winning machines therefor E21C25/00 - E21C39/00); Layouts therefor

IPC and CPC are identically structured here. All 4 subcodes exist in both systems.

IPC defines codes here since 1990.

Child Classifications

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  • E21C 41/18 for brown or hard coal since 1990 IPC+CPC Available in IPC and CPC
  • E21C 41/20 for rock salt or potash salt since 1990 IPC+CPC Available in IPC and CPC
  • E21C 41/22 for ores, e.g. mining placers since 1990 IPC+CPC Available in IPC and CPC
  • E21C 41/24 for oil-bearing deposits since 1990 IPC+CPC Available in IPC and CPC

Top Applicants

Top Applicants (IPC)

Class E21,2013–2023, worldwide · Source: EPO PATSTAT

  1. HALLIBURTON ENERGY SERVICES GROUP US 26,607
  2. PETROCHINA COMPANY 14,382
  3. SINOPEC (CHINA PETROCHEMICAL CORPORATION) 10,137
  4. CNPC (CHINA NATIONAL PETROLEUM CORPORATION) 6,517
  5. BAKER HUGHES US 6,269
  6. SCHLUMBERGER TECHNOLOGY US 5,929
  7. SAUDI ARABIAN OIL COMPANY SA 5,880
  8. SOUTHWEST PETROLEUM UNIVERSITY 4,477
  9. CHINA UNIVERSITY OF MINING AND TECHNOLOGY 4,357
  10. SCHLUMBERGER TECHNOLOGY NL 4,219

Top Applicants (CPC)

Class E21,2013–2023, worldwide · Source: EPO PATSTAT

  1. HALLIBURTON ENERGY SERVICES GROUP US 27,652
  2. SAUDI ARABIAN OIL COMPANY SA 7,755
  3. PETROCHINA COMPANY 7,025
  4. BAKER HUGHES US 6,589
  5. SCHLUMBERGER TECHNOLOGY US 6,151
  6. SINOPEC (CHINA PETROCHEMICAL CORPORATION) 4,443
  7. SCHLUMBERGER TECHNOLOGY NL 4,255
  8. CNPC (CHINA NATIONAL PETROLEUM CORPORATION) 3,991
  9. SERVICES PETROLIERS SCHLUMBERGER FR 3,300
  10. SCHLUMBERGER CANADA CA 3,086