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PCE
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DIFF Subgroup
E21D 5/11

with combinations of different materials, e.g. wood, metal, concrete (E21D5/01, E21D5/012, E21D5/016 take precedence)

Introduced: September 1968

Title

Titles differ between systems:

IPC: with combinations of different materials, e.g. wood, metal, concrete

CPC: with combinations of different materials, e.g. wood, metal, concrete (E21D5/01, E21D5/012, E21D5/016 take precedence)

Full Title

Full titles differ between systems:

IPC:

Lining shafts; Linings therefor > with combinations of different materials, e.g. wood, metal, concrete

CPC:

Lining shafts; Linings therefor (E21D11/00 takes precedence ) > with combinations of different materials, e.g. wood, metal, concrete (E21D5/01, E21D5/012, E21D5/016 take precedence)

No child classifications to compare. This is a leaf node in both 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