E21C 41/28
For brown or hard coal
Official title: for brown or hard coal
E21C41/28 (For brown or hard coal) appears on 21 US grants and 10 published applications in this corpus.
Search patents in E21C- Granted patents
- 21
- Published applications
- 10
- Assignees
- 12
- Inventors
- 40
- Latest grant
- 31 Dec 2024
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1977 | 1 | 0 |
| 1978 | 1 | 0 |
| 1979 | 2 | 0 |
| 1980 | 3 | 0 |
| 1981 | 2 | 0 |
| 1982 | 0 | 0 |
| 1983 | 1 | 0 |
| 1984 | 1 | 0 |
| 1985 | 0 | 0 |
| 1986 | 0 | 0 |
| 1987 | 0 | 0 |
| 1988 | 0 | 0 |
| 1989 | 0 | 0 |
| 1990 | 0 | 0 |
| 1991 | 1 | 0 |
| 1992 | 0 | 0 |
| 1993 | 0 | 0 |
| 1994 | 0 | 0 |
| 1995 | 0 | 0 |
| 1996 | 0 | 0 |
| 1997 | 0 | 0 |
| 1998 | 1 | 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 | 1 |
| 2017 | 1 | 1 |
| 2018 | 0 | 0 |
| 2019 | 0 | 1 |
| 2020 | 2 | 1 |
| 2021 | 0 | 2 |
| 2022 | 1 | 1 |
| 2023 | 2 | 2 |
| 2024 | 2 | 0 |
| 2025 | 0 | 0 |
| 2026 | 0 | 1 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Recent patents
- Method for slope geological disaster treatment and mineral resource recovery31 Dec 2024US 12,180,834 B2China University of Mining and Technology
- Dendritic reverse underground mining method for thin coal seam at end slope of strip mine28 May 2024US 11,994,027 B2China University of Mining and Technology
- Underground mining method for unexploited coal in boundary open-pit mine21 Nov 2023US 11,821,314 B2China Energy Group Xinjiang Energy Company Ltd
- Blasting technique17 Jan 2023US 11,555,681 B2Orica International Pte Ltd
- Method for radially mining open-pit end slope pressed coal5 Jul 2022US 11,377,952 B2China University of Mining and Technology
- Safe mining method for water-rich gently inclined coal seam3 Sep 2026US 2026/0258725 A1China University of Mining and Technology
- Underground mining method for unexploited coal in boundary open-pit mine27 Jul 2023US 2023/0235667 A1China Energy Group Xinjiang Energy Company Ltd
- Method for slope geological disaster treatment and mineral resource recovery2 Feb 2023US 2023/0030467 A1China University of Mining and Technology
- Dendritic reverse underground mining method for thin coal seam at end slope of strip mine4 Aug 2022US 2022/0243590 A1China University of Mining and Technology
- Method for radially mining open-pit end slope pressed coal19 Aug 2021US 2021/0254465 A1China University of Mining and Technology
Most cited
By later US patents
- Mining machine having rectangular thrust transmitting conveyor column27US 4,014,574 ABrowning & Bushman · 1977
- Method and apparatus for deep mining using chain driven in fixed direction17US 4,232,904 A1980
- Method of mining a mineral deposit seam15US 5,033,795 AThe United States of America as represented by the Secretary of the Interior · 1991
- Mining apparatus13US 4,160,566 AKerr-McGee Corporation · 1979
- Wall-to-wall surface mining process13US 5,782,539 A1998