E21D 23/0021
Comprising two walking elements
Official title: {comprising two walking elements}
E21D23/0021 (Comprising two walking elements) appears on 6 US grants and 1 published applications in this corpus.
Search patents in E21D- Granted patents
- 6
- Published applications
- 1
- Assignees
- 6
- Inventors
- 19
- Latest grant
- 13 Jan 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1978 | 1 | 0 |
| 1979 | 1 | 0 |
| 1980 | 0 | 0 |
| 1981 | 0 | 0 |
| 1982 | 3 | 0 |
| 1983 | 0 | 0 |
| 1984 | 0 | 0 |
| 1985 | 0 | 0 |
| 1986 | 0 | 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 | 0 | 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 | 0 |
| 2018 | 0 | 0 |
| 2019 | 0 | 0 |
| 2020 | 0 | 0 |
| 2021 | 0 | 0 |
| 2022 | 0 | 0 |
| 2023 | 0 | 0 |
| 2024 | 0 | 0 |
| 2025 | 0 | 1 |
| 2026 | 1 | 0 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Recent patents
- Asymmetric hydraulic supports for pseudo inclined mining in steeply dipping seam13 Jan 2026US 12,523,151 B2XI'AN UNIVERSITY OF SCIENCE AND TECHNOLOGY Xi'an, China
- Continuous sliding support gantry for a large passage9 Nov 1982US 4,358,224 ACharbonnages de France
- Sliding supporting gallery7 Sep 1982US 4,348,138 ACharbonnages de France
- Mine roof support19 Jan 1982US 4,311,417 AFletcher Sutcliffe Wild Limited
- Walking mine roof support20 Feb 1979US 4,140,430 ABochumer Eisenhutte Heintzmann GmbH & Co. KG
Most cited
By later US patents
- Sliding supporting gallery6US 4,348,138 ACharbonnages de France · 1982
- Walking mine roof support4US 4,140,430 ABochumer Eisenhutte Heintzmann GmbH & Co. KG · 1979
- Mine roof support4US 4,311,417 AFletcher Sutcliffe Wild Limited · 1982
- Continuous sliding support gantry for a large passage2US 4,358,224 ACharbonnages de France · 1982
- Guiding arrangement for underground excavating systems1US 4,065,931 ABochumer Eisenhutte Heintzmann GmbH & Co. KG · 1978