IPC Subgroup
E04C 5/1 Ducts
Introduced: September 1968
Last revised: January 2006
Full Title
Reinforcing elements, e.g. for concrete; Auxiliary elements therefor > Members specially adapted to be used in prestressed constructions > Ducts
Classification Context
- Section:
- FIXED CONSTRUCTIONS
- Class:
- BUILDING
- Subclass:
- STRUCTURAL ELEMENTS; BUILDING MATERIALS
Related Keywords
DUCTS for reinforcing elements in building
Top Applicants
Top 10 applicants by patent filingsfor class E04, 2013–2023, worldwide · Source: EPO PATSTAT
- CHINA CONSTRUCTION EIGHTH ENGINEERING DIVISION 6,575
- ZHEJIANG YASHA DECORATION COMPANY 4,488
- SGCC(STATE GRID CORPORATION OF CHINA) 4,427
- CHINA CONSTRUCTION SECOND ENGINEERING BUREAU 4,352
- CHINA MCC17 GROUP COMPANY 3,122
- GOLD MANTIS FINE DECORATION TECHNOLOGY (SUZHOU) COMPANY 2,605
- SHENYANG JIANZHU UNIVERSITY 2,420
- CHINA CONSTRUCTION SEVENTH ENGINEERING DIVISION COMPANY 2,284
- CHINA CONSTRUCTION FIFTH ENGINEERING DIVISION CORPORATION 2,008
- CHINA CONSTRUCTION FIRST BUILDING (GROUP) CORPORATION 1,967