E21D 15/51
Specially adapted to hydraulic, pneumatic, or hydraulic-pneumatic props
Official title: specially adapted to hydraulic, pneumatic, or hydraulic-pneumatic props, e.g. arrangements of relief valves {(not used, see subgroups and E21D15/44)}
E21D15/51 (Specially adapted to hydraulic, pneumatic, or hydraulic-pneumatic props) appears on 21 US grants and 7 published applications in this corpus.
Search patents in E21D- Granted patents
- 21
- Published applications
- 7
- Assignees
- 24
- Inventors
- 47
- Latest grant
- 13 Apr 2021
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1978 | 2 | 0 |
| 1979 | 1 | 0 |
| 1980 | 0 | 0 |
| 1981 | 3 | 0 |
| 1982 | 0 | 0 |
| 1983 | 0 | 0 |
| 1984 | 0 | 0 |
| 1985 | 1 | 0 |
| 1986 | 2 | 0 |
| 1987 | 1 | 0 |
| 1988 | 0 | 0 |
| 1989 | 0 | 0 |
| 1990 | 0 | 0 |
| 1991 | 0 | 0 |
| 1992 | 1 | 0 |
| 1993 | 0 | 0 |
| 1994 | 1 | 0 |
| 1995 | 2 | 0 |
| 1996 | 0 | 0 |
| 1997 | 2 | 0 |
| 1998 | 0 | 0 |
| 1999 | 1 | 0 |
| 2000 | 1 | 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 | 1 |
| 2010 | 0 | 0 |
| 2011 | 0 | 0 |
| 2012 | 0 | 0 |
| 2013 | 0 | 0 |
| 2014 | 0 | 2 |
| 2015 | 0 | 1 |
| 2016 | 0 | 0 |
| 2017 | 0 | 1 |
| 2018 | 0 | 0 |
| 2019 | 1 | 0 |
| 2020 | 1 | 0 |
| 2021 | 1 | 1 |
| 2022 | 0 | 0 |
| 2023 | 0 | 0 |
| 2024 | 0 | 0 |
| 2025 | 0 | 1 |
By publication year. Applications have been published since 2001.
Subgroups
Granted patents
Recent patents
- Hydraulic support monitoring support pose in real time based on inertia measurement unit and detection method thereof13 Apr 2021US 10,975,695 B2China University of Mining and Technology
- Hydraulic support unit and hydraulic support for anti-rock burst roadway15 Sep 2020US 10,774,642 B1Beijing Chengtian Hengye Coal Mine Equipment Co. Ltd.
- Sleeve holder for a hydraulic cylinder20 Aug 2019US 10,385,888 B2Caterpillar Global Mining Europe GmbH
- Hydraulically trippable check valve for underground mine support hydraulics13 Jun 2000US 6,073,654 ADBT Deutsche Bergbau-Technik GmbH
- Valves14 Sep 1999US 5,950,673 AJoy MM Delaware, Inc.
- Support prop27 Mar 2025US 2025/0101869 A1Msp Mine Support Products (Pty) Ltd
- Hydraulic support monitoring support pose in real time based on inertia measurement unit and detection method thereof14 Jan 2021US 2021/0010373 A1China University of Mining and Technology
- Sleeve holder for a hydraulic cylinder20 Apr 2017US 2017/0108016 A1Caterpillar Global Mining Europe GmbH
- Valve24 Sep 2015US 2015/0267822 A1Mine Support Products (Pty) Ltd
- Support prop13 Mar 2014US 2014/0072374 A1Elbroc Mining Products (Pty) Ltd
Most cited
By later US patents
- Water-based industrial fluids54US 4,257,902 ASinger & Hersch Industrial Development (Pty.) Ltd. · 1981
- Pressure-limiting valve23US 4,660,595 AHermann Hemscheidt Maschinenfabrik GmbH & Co. · 1987
- Pressure relief valve16US 4,091,838 ADowty Mining Equipment Limited · 1978
- Excess pressure valve particularly for a fluid pressure operated telescopic supporting element employed in underground mining11US 4,274,435 AThyssen Industrie AG · 1981
- Valve units for use in hydraulic control systems of mining equipment11US 5,159,872 AGewerkschaft Eisenhutte Westfalia · 1992