E21D 23/26
Hydraulic or pneumatic control
E21D23/26 (Hydraulic or pneumatic control) appears on 50 US grants and 20 published applications in this corpus.
Search patents in E21D- Granted patents
- 50
- Published applications
- 20
- Assignees
- 28
- Inventors
- 66
- Latest grant
- 4 Nov 2025
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 1 | 0 |
| 1977 | 1 | 0 |
| 1978 | 1 | 0 |
| 1979 | 5 | 0 |
| 1980 | 2 | 0 |
| 1981 | 2 | 0 |
| 1982 | 2 | 0 |
| 1983 | 3 | 0 |
| 1984 | 2 | 0 |
| 1985 | 1 | 0 |
| 1986 | 4 | 0 |
| 1987 | 4 | 0 |
| 1988 | 0 | 0 |
| 1989 | 0 | 0 |
| 1990 | 1 | 0 |
| 1991 | 0 | 0 |
| 1992 | 0 | 0 |
| 1993 | 0 | 0 |
| 1994 | 0 | 0 |
| 1995 | 1 | 0 |
| 1996 | 0 | 0 |
| 1997 | 0 | 0 |
| 1998 | 0 | 0 |
| 1999 | 0 | 0 |
| 2000 | 1 | 0 |
| 2001 | 0 | 0 |
| 2002 | 1 | 0 |
| 2003 | 1 | 1 |
| 2004 | 0 | 1 |
| 2005 | 0 | 1 |
| 2006 | 1 | 2 |
| 2007 | 0 | 1 |
| 2008 | 2 | 0 |
| 2009 | 1 | 0 |
| 2010 | 0 | 0 |
| 2011 | 0 | 0 |
| 2012 | 0 | 2 |
| 2013 | 0 | 1 |
| 2014 | 2 | 1 |
| 2015 | 1 | 1 |
| 2016 | 2 | 2 |
| 2017 | 0 | 0 |
| 2018 | 1 | 0 |
| 2019 | 1 | 0 |
| 2020 | 1 | 3 |
| 2021 | 2 | 1 |
| 2022 | 2 | 1 |
| 2023 | 0 | 0 |
| 2024 | 0 | 0 |
| 2025 | 1 | 1 |
| 2026 | 0 | 1 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Recent patents
- External fluid bar for fluid driven cylinder4 Nov 2025US 12,460,546 B1
- Magnetically controlled material-based magnetorheological pilot operated safety valve for hydraulic support, and applications of the same25 Oct 2022US 11,480,263 B2Shandong University of Science and Technology
- Hydraulic shield support system and pressure intensifier26 Jul 2022US 11,396,894 B2Caterpillar Global Mining Europe GmbH
- High stress impact detection for a longwall shearer23 Nov 2021US 11,180,992 B2Joy Global Underground Mining LLC
- Automated support of a gate entry for underground full extraction mining12 Jan 2021US 10,890,068 B2
- Underground mining system and method30 Jul 2026US 2026/0218612 A1
- Roof Support Unit for a Mining Machine22 May 2025US 2025/0163807 A1Caterpillar Inc.
- Magnetically controlled material-based magnetorheological pilot operated safety valve for hydraulic support, and applications of the same24 Mar 2022US 2022/0090697 A1Shandong University of Science and Technology
- High stress impact detection for a longwall shearer19 Aug 2021US 2021/0254462 A1Joy Global Underground Mining LLC
- Hydraulic shield support system and pressure intensifier31 Dec 2020US 2020/0408226 A1Caterpillar Global Mining Europe GmbH
Most cited
By later US patents
- Multi-core hydraulic duct27US 4,149,567 AGewerkschaft Eisenhutte Westfalia · 1979
- Method and device for monitoring the load on hydraulic powered shield supports for underground mining18US 6,056,481 ADBT Automation GmbH · 2000
- Control system for longwall face alignment16US 6,481,802 B1Tiefenbach Bergbautechnik GmbH · 2002
- Hydraulic coupling device13US 4,247,135 AGewerkschaft Eisenhutte Westfalia · 1981
- Control unit for an electro-hydraulic roof support control arrangement12US 4,378,027 AGewerkschaft Eisenhutte Westfalia · 1983