E21D 23/18 of advancing mechanisms
Introduced: September 1968
Full Title
Full titles differ between systems:
Mine roof supports for step-by-step movement, e.g. in combination with provisions for shifting of conveyors, mining machines or guides therefor > Hydraulic or pneumatic features, e.g. circuits, arrangement or adaptation of valves, setting or retracting devices > of advancing mechanisms
Mine roof supports for step- by- step movement, e.g. in combination with provisions for shifting of conveyors, mining machines, or guides therefor ( shifting of mine conveyors at the working face E21F13/08) > Hydraulic or pneumatic features, e.g. circuits, arrangement or adaptation of valves, setting or retracting devices > of advancing mechanisms
IPC and CPC are identically structured here. All 3 subcodes exist in both systems.
Child Classifications
Navigate with arrow keys, Enter to open
- E21D 23/24 the advancing mechanisms being separate from the supporting construction 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