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CPC Subclass Not Allocatable
E21F

SAFETY DEVICES, TRANSPORT, FILLING-UP, RESCUE, VENTILATION, OR DRAINING IN OR OF MINES OR TUNNELS

Description

E21F covers safety and operational infrastructure systems specific to underground mining and tunneling environments. This subclass encompasses devices and methods for worker protection, personnel rescue, material transport, mine ventilation systems, water drainage, and mine filling operations. The classification addresses the unique hazards of subsurface work, including gas accumulation, flooding, equipment movement, and emergency evacuation requirements. Adjacent classes E21C (drilling and boring) and E21D (mining) focus on extraction methods, whereas E21F emphasizes the support systems and safety infrastructure necessary for safe mining and tunnel operations.

10 direct subcodes

Child Classifications

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  • E21F 11/00 Rescue devices or other safety devices, e.g. safety chambers or escape ways (breathing aids for curative purposes A61H31/00; respiratory apparatus A62B7/00; breathing apparatus for accidentally buried persons A62B33/00)
  • E21F 3/00 Cooling or drying of air (air-conditioning rooms or spaces in general F24F)
  • E21F 7/00 Methods or devices for drawing- off gases with or without subsequent use of the gas for any purpose
  • E21F 9/00 Devices preventing sparking of machines or apparatus (preventing sparking of electric machines or apparatus H01K, H02K)

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