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DIFF Main Group
E21D 9/00

Tunnels or galleries, with or without linings; Methods or apparatus for making thereof (E02D29/045, E02D29/063 take precedence; linings per se E21D11/00); Layout of tunnels or galleries

Introduced: September 1968

Title

Titles differ between systems:

IPC: Tunnels or galleries, with or without linings; Methods or apparatus for making thereof; Layout of tunnels or galleries

CPC: Tunnels or galleries, with or without linings; Methods or apparatus for making thereof (E02D29/045, E02D29/063 take precedence; linings per se E21D11/00); Layout of tunnels or galleries

Full Title

Full titles differ between systems:

IPC:

Tunnels or galleries, with or without linings; Methods or apparatus for making thereof; Layout of tunnels or galleries

CPC:

Tunnels or galleries, with or without linings; Methods or apparatus for making thereof (E02D29/045, E02D29/063 take precedence; linings per se E21D11/00); Layout of tunnels or galleries

Of 13 combined children, 7 exist in both systems.

6 codes are CPC-only extensions.

2 shared codes have differing titles between IPC and CPC.

Child Classifications

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  • E21D 9/005 CPC only CPC only
  • E21D 9/006 CPC only CPC only
  • E21D 9/008 CPC only CPC only
  • E21D 9/01 Methods or apparatus for enlarging or restoring the cross-section of tunnels, e.g. by restoring the floor to its original level since 2000 IPC+CPC Available in IPC and CPC
  • E21D 9/02 Driving inclined tunnels or galleries IPC+CPC Available in IPC and CPC
  • E21D 9/03 CPC only CPC only
  • E21D 9/04 Driving tunnels or galleries through loose materials; Apparatus therefor not otherwise provided for IPC+CPC Available in IPC and CPC
  • E21D 9/14 Layout of tunnels or galleries; Constructional features of tunnels or galleries, not otherwise provided for, e.g. portals, day-light attenuation at tunnel openings since 1980 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