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DIFF Main Group
E21D 5/00

Lining shafts; Linings therefor (E21D11/00 takes precedence )

Introduced: September 1968

Title

Titles differ between systems:

IPC: Lining shafts; Linings therefor

CPC: Lining shafts; Linings therefor (E21D11/00 takes precedence )

Full Title

Full titles differ between systems:

IPC:

Lining shafts; Linings therefor

CPC:

Lining shafts; Linings therefor (E21D11/00 takes precedence )

IPC and CPC are identically structured here. All 8 subcodes exist in both systems.

4 shared codes have differing titles between IPC and CPC.

Child Classifications

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  • E21D 5/01 using prefabricated lining lowered into a hole filled with liquid or viscous mass IPC+CPC Available in IPC and CPC
  • E21D 5/012 Use of fluid-tight or anti-friction material on outside of, or between, lining layers IPC+CPC Available in IPC and CPC
  • E21D 5/016 Bearer curbs IPC+CPC Available in IPC and CPC
  • E21D 5/02 with wood (E21D5/01, E21D5/012, E21D5/016 take precedence) IPC+CPC Available in IPC and CPC
  • E21D 5/04 with brick, concrete, stone, or similar building materials (E21D5/01, E21D5/012, E21D5/016 take precedence) IPC+CPC Available in IPC and CPC
  • E21D 5/11 with combinations of different materials, e.g. wood, metal, concrete (E21D5/01, E21D5/012, E21D5/016 take precedence) IPC+CPC Available in IPC and CPC
  • E21D 5/12 Accessories for making shaft linings, e.g. suspended cradles, shutterings 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