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IPC Subgroup
E21C 27/2

Mineral freed by means not involving slitting

Introduced: September 1968

Last revised: January 2006

Full Title

Machines which completely free the mineral from the seam > Mineral freed by means not involving slitting

Classification Context

Section:
FIXED CONSTRUCTIONS
Class:
EARTH OR ROCK DRILLING; MINING
Subclass:
MINING OR QUARRYING

7 direct subcodes

Child Classifications

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  • E21C 27/22 by rotary drills with breaking-down means, e.g. wedge-shaped drills
  • E21C 27/24 by milling means acting on the full working face
  • E21C 27/26 by closely adjacent cutter chains acting on the full working face
  • E21C 27/28 by percussive drills with breaking-down means, e.g. wedge-shaped tools
  • E21C 27/3 by jaws, buckets, or scoops that scoop-out the mineral
  • E21C 27/46 by percussed planing means

Top Applicants

Top 10 applicants by patent filingsfor 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