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IPC Subgroup
E04D 3/35

Roofing slabs or stiff sheets comprising two or more layers, e.g. for insulation

Introduced: September 1968

Last revised: January 2006

Full Title

Roof covering by making use of flat or curved slabs or stiff sheets > Roofing slabs or stiff sheets comprising two or more layers, e.g. for insulation

Classification Context

Section:
FIXED CONSTRUCTIONS
Class:
BUILDING
Subclass:
ROOF COVERINGS; SKY-LIGHTS; GUTTERS; ROOF-WORKING TOOLS

Filing statistics

IPC E04D 3/35 belongs to the parent subclass E04D, which recorded 74,274 patent applications worldwide between 2013 and 2023. Annual filings grew from 4,251 in 2013 to 9,324 in 2023 (+119%). The most active applicants in class E04 are CHINA CONSTRUCTION EIGHTH ENGINEERING DIVISION (6,575 applications), ZHEJIANG YASHA DECORATION COMPANY (4,488 applications) and SGCC(STATE GRID CORPORATION OF CHINA) (4,427 applications).

Source: EPO PATSTAT, worldwide filings

Top Applicants

Top 10 applicants by patent filingsfor class E04, 2013–2023, worldwide · Source: EPO PATSTAT

  1. CHINA CONSTRUCTION EIGHTH ENGINEERING DIVISION 6,575
  2. ZHEJIANG YASHA DECORATION COMPANY 4,488
  3. SGCC(STATE GRID CORPORATION OF CHINA) 4,427
  4. CHINA CONSTRUCTION SECOND ENGINEERING BUREAU 4,352
  5. CHINA MCC17 GROUP COMPANY 3,122
  6. GOLD MANTIS FINE DECORATION TECHNOLOGY (SUZHOU) COMPANY 2,605
  7. SHENYANG JIANZHU UNIVERSITY 2,420
  8. CHINA CONSTRUCTION SEVENTH ENGINEERING DIVISION COMPANY 2,284
  9. CHINA CONSTRUCTION FIFTH ENGINEERING DIVISION CORPORATION 2,008
  10. CHINA CONSTRUCTION FIRST BUILDING (GROUP) CORPORATION 1,967