E21D 23/00
Mine roof supports for step- by- step movement
Official title: Mine roof supports for step- by- step movement, e.g. in combination with provisions for shifting of conveyors, mining machines, or guides therefor ({transport of mine roof support units E21F13/008; } shifting of mine conveyors at the working face E21F13/08)
E21D23/00 (Mine roof supports for step- by- step movement) appears on 491 US grants and 140 published applications in this corpus.
Search patents in E21D- Granted patents
- 491
- Published applications
- 140
- Assignees
- 162
- Inventors
- 697
- Latest grant
- 18 Aug 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 22 | 0 |
| 1977 | 28 | 0 |
| 1978 | 41 | 0 |
| 1979 | 21 | 0 |
| 1980 | 29 | 0 |
| 1981 | 21 | 0 |
| 1982 | 19 | 0 |
| 1983 | 23 | 0 |
| 1984 | 22 | 0 |
| 1985 | 21 | 0 |
| 1986 | 18 | 0 |
| 1987 | 14 | 0 |
| 1988 | 15 | 0 |
| 1989 | 10 | 0 |
| 1990 | 14 | 0 |
| 1991 | 9 | 0 |
| 1992 | 9 | 0 |
| 1993 | 8 | 0 |
| 1994 | 2 | 0 |
| 1995 | 4 | 0 |
| 1996 | 2 | 0 |
| 1997 | 2 | 0 |
| 1998 | 2 | 0 |
| 1999 | 2 | 0 |
| 2000 | 1 | 0 |
| 2001 | 0 | 0 |
| 2002 | 4 | 2 |
| 2003 | 6 | 3 |
| 2004 | 1 | 5 |
| 2005 | 2 | 1 |
| 2006 | 2 | 12 |
| 2007 | 4 | 5 |
| 2008 | 9 | 2 |
| 2009 | 4 | 1 |
| 2010 | 2 | 4 |
| 2011 | 0 | 9 |
| 2012 | 1 | 9 |
| 2013 | 8 | 5 |
| 2014 | 7 | 9 |
| 2015 | 8 | 5 |
| 2016 | 8 | 6 |
| 2017 | 5 | 15 |
| 2018 | 7 | 8 |
| 2019 | 12 | 4 |
| 2020 | 11 | 8 |
| 2021 | 7 | 5 |
| 2022 | 5 | 5 |
| 2023 | 4 | 6 |
| 2024 | 5 | 5 |
| 2025 | 5 | 3 |
| 2026 | 5 | 3 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Subgroups
Granted patents
- E21D 23/04Structural features of the supporting construction215
- E21D 23/0004Along the working face149
- E21D 23/16Hydraulic or pneumatic features122
- E21D 23/12Control97
- E21D 23/08Advancing mechanisms80
- E21D 23/03Mine roof supports for step- by- step movement: having protective means36
- E21D 23/0086In galleries30
- E21D 23/006Provided with essential hydraulic devices14
All 12 subgroupsShow fewer
- E21D 23/0052Mine roof supports for step- by- step movement: with advancing shifting devices5
- E21D 23/0082Mine roof supports for step- by- step movement: specially adapted for vertical5
- E21D 23/0047Without essential shifting devices2
- E21D 23/0056Mine roof supports for step- by- step movement: with individual advancing shifting1
Recent patents
- System and method for controlling roof support18 Aug 2026US 12,709,982 B2Joy Global Underground Mining LLC
- Tunneling system28 Jul 2026US 12,692,790 B2Ccteg Taiyuan Research Institute
- Bolter miner and tunneling system31 Mar 2026US 12,590,540 B2Ccteg Taiyuan Research Institute
- Detection device and method for working surface, terminal, and storage medium24 Mar 2026US 12,584,410 B2Taiyuan University of Technology
- 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
- Underground mining system and method30 Jul 2026US 2026/0218612 A1
- Method for reliability assessment of shield tunnel structure based on joint safety reserve18 Jun 2026US 2026/0168380 A1Tongji University
- Integrated rapid excavation equipment for rock roadways and method thereof28 May 2026US 2026/0146533 A1China University of Mining and Technology
- Roof Support Unit for a Mining Machine22 May 2025US 2025/0163807 A1Caterpillar Inc.
- Asymmetric hydraulic supports for pseudo inclined mining in steeply dipping seam10 Apr 2025US 2025/0116192 A1Xi'an University of Science and Technology
Most cited
By later US patents
- Long range multiple point wireless control and monitoring system121US 4,968,978 AStolar, Inc. · 1990
- Long range multiple point wireless control and monitoring system86US 5,087,099 AStolar, Inc. · 1992
- Method of transmitting data from a drillhead57US 5,268,683 AStolar, Inc. · 1993
- Method of controlling the movement of a longwall excavation front, especially the face or breast of a coal seam29US 4,887,935 ABochumer Eisenhutte Heintzmann GmbH & Co. KG · 1989
- Method and a device for detecting the presence of personnel in underground mining28US 6,512,312 B1DBT Automation GmbH · 2003