Lining predominantly with metal

Introduced: September 1968

Full Title

Full titles differ between systems:

IPC:

Lining tunnels, galleries or other underground cavities, e.g. large underground chambers; Linings therefor; Making such linings , e.g. by assembling > Lining predominantly with metal

CPC:

Lining tunnels, galleries or other underground cavities, e.g. large underground chambers; Linings therefor; Making such linings in situ, e.g. by assembling (E21D15/00 - E21D23/00 take precedence; specially for shafts E21D5/00; ; lining pressure water galleries, linings therefor E02B9/06) > Lining predominantly with metal

IPC and CPC are identically structured here. All 6 subcodes exist in both systems.

3 shared codes have differing titles between IPC and CPC.

Child Classifications

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E21D 11/15 Plate linings; Laggings, i.e. linings designed for holding back formation material or for transmitting the load to main supporting members (insulation E21D11/38) since 1974 +3 CPC IPC+CPC Available in IPC and CPC
E21D 11/18 Arch members +2 CPC IPC+CPC Available in IPC and CPC
E21D 11/28 Longitudinal struts IPC+CPC Available in IPC and CPC
E21D 11/30 Bases for lower arch members (for props E21D15/54) IPC+CPC Available in IPC and CPC
E21D 11/34 Joints between vertical props and horizontal top bars (end caps forming part of the props E21D15/54 ) IPC+CPC Available in IPC and CPC
E21D 11/36 Linings or supports specially shaped for tunnels or galleries of irregular cross-section since 1974 +3 CPC IPC+CPC Available in IPC and CPC

Top Applicants

Top Applicants (IPC)

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

Top Applicants (CPC)

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

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