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DIFF Subgroup
F28F 1/42

the means being both outside and inside the tubular element

Introduced: September 1968

Full Title

Full titles differ between systems:

IPC:

Tubular elements; Assemblies of tubular elements > Tubular elements or assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses > the means being both outside and inside the tubular element

CPC:

Tubular elements; Assemblies of tubular elements (specially adapted for movement F28F5/00) > Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses (crimped or corrugated elements F28F1/06, F28F1/08) > the means being both outside and inside the tubular element

CPC subdivides this area 4x more granularly than IPC with 3 additional codes.

3 codes are CPC-only extensions.

Note: 1 CPC extensions are marked as secondary classification only.

Child Classifications

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Top Applicants

Top Applicants (IPC)

Class F28,2013–2023, worldwide · Source: EPO PATSTAT

  1. VALEO SYSTEMES THERMIQUES FR 1,902
  2. MITSUBISHI ELECTRIC CORPORATION JP 1,327
  3. GREE ELECTRIC APPLIANCES 1,152
  4. MAHLE INTERNATIONAL DE 999
  5. ALFA LAVAL SE 960
  6. HANON SYSTEMS KR 917
  7. DENSO CORPORATION 905
  8. DENSO CORPORATION JP 802
  9. CHINESE ACADEMY OF SCIENCES 787
  10. XIAN THERMAL POWER RESEARCH INSTITUTE COMPANY 762

Top Applicants (CPC)

Class F28,2013–2023, worldwide · Source: EPO PATSTAT

  1. VALEO SYSTEMES THERMIQUES FR 1,945
  2. MITSUBISHI ELECTRIC CORPORATION JP 1,518
  3. MAHLE INTERNATIONAL DE 1,120
  4. ALFA LAVAL SE 1,085
  5. HANON SYSTEMS KR 939
  6. DENSO CORPORATION JP 900
  7. LG ELECTRONICS KR 861
  8. HAMILTON SUNDSTRAND US 795
  9. DAIKIN INDUSTRIES JP 608
  10. DENSO CORPORATION 537