E21D 11/20
Special cross- sections
Official title: Special cross- sections, e.g. corrugated {(for props E21D15/502; for caps E21D17/01)}
E21D11/20 (Special cross- sections) appears on 11 US grants and 6 published applications in this corpus.
Search patents in E21D- Granted patents
- 11
- Published applications
- 6
- Assignees
- 10
- Inventors
- 26
- Latest grant
- 19 May 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 1 | 0 |
| 1977 | 1 | 0 |
| 1978 | 1 | 0 |
| 1979 | 0 | 0 |
| 1980 | 1 | 0 |
| 1981 | 0 | 0 |
| 1982 | 0 | 0 |
| 1983 | 0 | 0 |
| 1984 | 2 | 0 |
| 1985 | 0 | 0 |
| 1986 | 1 | 0 |
| 1987 | 0 | 0 |
| 1988 | 0 | 0 |
| 1989 | 0 | 0 |
| 1990 | 0 | 0 |
| 1991 | 0 | 0 |
| 1992 | 0 | 0 |
| 1993 | 0 | 0 |
| 1994 | 0 | 0 |
| 1995 | 0 | 0 |
| 1996 | 0 | 0 |
| 1997 | 0 | 0 |
| 1998 | 0 | 0 |
| 1999 | 0 | 0 |
| 2000 | 0 | 0 |
| 2001 | 0 | 0 |
| 2002 | 0 | 0 |
| 2003 | 0 | 0 |
| 2004 | 0 | 0 |
| 2005 | 0 | 0 |
| 2006 | 0 | 0 |
| 2007 | 1 | 0 |
| 2008 | 0 | 0 |
| 2009 | 0 | 0 |
| 2010 | 0 | 0 |
| 2011 | 0 | 0 |
| 2012 | 0 | 0 |
| 2013 | 0 | 0 |
| 2014 | 0 | 0 |
| 2015 | 0 | 0 |
| 2016 | 0 | 0 |
| 2017 | 0 | 1 |
| 2018 | 0 | 0 |
| 2019 | 0 | 0 |
| 2020 | 0 | 0 |
| 2021 | 0 | 2 |
| 2022 | 1 | 1 |
| 2023 | 0 | 0 |
| 2024 | 0 | 1 |
| 2025 | 1 | 1 |
| 2026 | 1 | 0 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Recent patents
- Pipe rehabilitation method19 May 2026US 12,631,281 B2Shonan Gosei-Jushi-Seisakusho K. K.
- Structural plates and methods of constructing arch-shaped structures using structural plates11 Mar 2025US 12,247,390 B2Ail International Inc.
- Adjustable lattice girder8 Feb 2022US 11,242,750 B2FCI Holdings Delaware, Inc.
- Reinforcement of arch type structure with beveled/skewed ends15 May 2007US 7,217,064 B1
- Peripherally flexible prop arch for mining tracks, tunnels or the like23 Dec 1986US 4,630,973 ABochumer Eisenhuette Heintzmann GmbH & Co.
- Structural plates and methods of constructing arch-shaped structures using structural plates10 Jul 2025US 2025/0223774 A1Ail International Inc.
- Pipe rehabilitation method18 Jul 2024US 2024/0240740 A1Shonan Gosei-Jushi-Seisakusho K. K.
- Structural plates and methods of constructing arch-shaped structures using structural plates1 Dec 2022US 2022/0381023 A1Ail International Inc.
- Tube segment for evacuated tube transport system23 Sep 2021US 2021/0291880 A1Tata Steel Nederland Technology B.V.
- Adjustable Lattice Girder27 May 2021US 2021/0156251 A1FCI Holdings Delaware, Inc.
Most cited
By later US patents
- Reinforcement of arch type structure with beveled/skewed ends11US 7,217,064 B12007
- Continuous gallery construction, in particular for underground mine tunnels7US 4,439,065 A1984
- Wall element for an underground gallery7US 4,465,404 ABochumer Eisenhuette Heintzmann GmbH & Co. · 1984
- Voussoir for a lining, and method for constructing the lining5US 3,946,567 APont-A-Mousson S. A. · 1976
- Wall supporting arrangement, especially for supporting mine gallery walls5US 4,187,037 ARudolf Seiz · 1980