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CPC Subgroup
E21C 27/20

Mineral freed by means not involving slitting

Full Title

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

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 27/30 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 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