Skip to content
Search Classifications
Search for IPC and CPC classification codes or keywords
DIFF Subgroup
F15B 21/04

Special measures taken in connection with the properties of the fluid

Introduced: September 1968

Full Title

Common features of fluid actuator systems; Fluid-pressure actuator systems or details thereof, not covered by any other group of this subclass > Special measures taken in connection with the properties of the fluid

IPC and CPC are identically structured here. All 6 subcodes exist in both systems.

IPC defines codes here since 2019.

Child Classifications

Navigate with arrow keys, Enter to open

  • F15B 21/041 Removal or measurement of solid or liquid contamination, e.g. filtering since 2019 IPC+CPC Available in IPC and CPC
  • F15B 21/044 Removal or measurement of undissolved gas, e.g. de-aeration, venting or bleeding since 2019 IPC+CPC Available in IPC and CPC
  • F15B 21/045 Compensating for variations in viscosity or temperature since 2019 IPC+CPC Available in IPC and CPC
  • F15B 21/047 Preventing foaming, churning or cavitation since 2019 IPC+CPC Available in IPC and CPC
  • F15B 21/048 Arrangements for compressed air preparation, e.g. comprising air driers, air condensers, filters, lubricators or pressure regulators since 2019 IPC+CPC Available in IPC and CPC

Top Applicants

Top Applicants (IPC)

Class F15,2013–2023, worldwide · Source: EPO PATSTAT

  1. ROBERT BOSCH DE 1,079
  2. SCHAEFFLER TECHNOLOGIES & COMPANY DE 980
  3. SMC CORPORATION JP 737
  4. HITACHI CONSTRUCTION MACHINERY COMPANY JP 674
  5. KYB CORPORATION JP 525
  6. CATERPILLAR US 461
  7. FESTO & COMPANY DE 451
  8. ZHEJIANG UNIVERSITY 448
  9. HITACHI CONSTRUCTION MACHINERY COMPANY 442
  10. XUZHOU HEAVY MACHINERY COMPANY 404

Top Applicants (CPC)

Class F15,2013–2023, worldwide · Source: EPO PATSTAT

  1. ROBERT BOSCH DE 1,281
  2. SMC CORPORATION JP 865
  3. HITACHI CONSTRUCTION MACHINERY COMPANY JP 814
  4. KYB CORPORATION JP 584
  5. SCHAEFFLER TECHNOLOGIES & COMPANY DE 536
  6. CATERPILLAR US 532
  7. FESTO & COMPANY DE 486
  8. JOHN DEERE US 419
  9. KAWASAKI HEAVY IND JP 368
  10. HAMILTON SUNDSTRAND US 368