IPC Main Group
E21C 35/00 Details of, or accessories for, machines for slitting or completely freeing the mineral from the seam, not provided for in groups , or
Introduced: September 1968
Last revised: January 2006
Classification Context
- Section:
- FIXED CONSTRUCTIONS
- Class:
- EARTH OR ROCK DRILLING; MINING
- Subclass:
- MINING OR QUARRYING
8 direct subcodes
Child Classifications
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- E21C 35/02 Locking equipment for slewable parts
- E21C 35/04 Safety devices
- E21C 35/06 Equipment for positioning the whole machine in relation to its sub-structure
- E21C 35/08 Guiding the machine
- E21C 35/18 Mining picks; Holders therefor
- E21C 35/2 General features of equipment for removal of chippings, e.g. for loading on conveyor
- E21C 35/22 Equipment for preventing the formation of, or for removal of, dust
- E21C 35/24 Remote control specially adapted for machines for slitting or completely freeing the mineral
Top Applicants
Top 10 applicants by patent filingsfor 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