E21D 21/00
Anchoring-bolts for roof, floor in galleries or longwall working, or shaft-lining protection
Official title: Anchoring-bolts for roof, floor {in galleries or longwall working}, or shaft-lining protection ({ground anchors E02D5/80; anchorings for building constructions E04B1/41, E21D21/00}; dowels or other devices fastened in walls or the like by inserting them in holes made therein for that purpose F16B13/00 {; bolts with visible load G01L1/00})
E21D21/00 (Anchoring-bolts for roof, floor in galleries or longwall working, or shaft-lining protection) appears on 773 US grants and 535 published applications in this corpus.
Search patents in E21D- Granted patents
- 773
- Published applications
- 535
- Assignees
- 336
- Inventors
- 1,144
- Latest grant
- 18 Aug 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 9 | 0 |
| 1977 | 12 | 0 |
| 1978 | 12 | 0 |
| 1979 | 13 | 0 |
| 1980 | 8 | 0 |
| 1981 | 28 | 0 |
| 1982 | 23 | 0 |
| 1983 | 18 | 0 |
| 1984 | 20 | 0 |
| 1985 | 28 | 0 |
| 1986 | 17 | 0 |
| 1987 | 26 | 0 |
| 1988 | 11 | 0 |
| 1989 | 12 | 0 |
| 1990 | 14 | 0 |
| 1991 | 17 | 0 |
| 1992 | 11 | 0 |
| 1993 | 16 | 0 |
| 1994 | 17 | 0 |
| 1995 | 17 | 0 |
| 1996 | 13 | 0 |
| 1997 | 14 | 0 |
| 1998 | 20 | 0 |
| 1999 | 13 | 0 |
| 2000 | 9 | 0 |
| 2001 | 9 | 7 |
| 2002 | 11 | 13 |
| 2003 | 14 | 12 |
| 2004 | 10 | 19 |
| 2005 | 9 | 18 |
| 2006 | 19 | 16 |
| 2007 | 4 | 22 |
| 2008 | 13 | 18 |
| 2009 | 8 | 25 |
| 2010 | 11 | 27 |
| 2011 | 18 | 30 |
| 2012 | 17 | 27 |
| 2013 | 13 | 22 |
| 2014 | 25 | 25 |
| 2015 | 15 | 31 |
| 2016 | 14 | 15 |
| 2017 | 12 | 15 |
| 2018 | 14 | 31 |
| 2019 | 24 | 20 |
| 2020 | 23 | 31 |
| 2021 | 17 | 21 |
| 2022 | 19 | 16 |
| 2023 | 12 | 25 |
| 2024 | 16 | 22 |
| 2025 | 16 | 13 |
| 2026 | 12 | 14 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Subgroups
Granted patents
- E21D 21/0026Anchoring-bolts for roof, floor in galleries or longwall working, or shaft-lining protection452
- E21D 21/008Anchoring or tensioning means287
- E21D 21/0093Accessories108
- E21D 21/0086Bearing plates84
- E21D 21/0006Anchoring-bolts for roof, floor in galleries or longwall working, or shaft-lining protection59
- E21D 21/02Anchoring-bolts for roof, floor in galleries or longwall working, or shaft-lining protection52
- E21D 21/0013Protection against corrosion13
- E21D 21/002Anchoring-bolts for roof, floor in galleries or longwall working, or shaft-lining protection3
Recent patents
- Drilling and bolting tool18 Aug 2026US 12,709,981 B2Joy Global Underground Mining LLC
- Deformable anchor cable28 Jul 2026US 12,692,791 B2Fuzhou University
- Tunnel constraint anchor cable and method for improving stability of initial support structure14 Jul 2026US 12,680,451 B2Chang An University
- Autonomous roof bolter with sensor and related methods16 Jun 2026US 12,655,761 B2J.H. Fletcher & Co.
- Active control method and device for large deformation of deep thin-bedded surrounding rock9 Jun 2026US 12,650,076 B2Huaneng Lancang River Hydropower Inc.
- Dynamic rock bolt assembly8 Oct 2026US 2026/0309029 A1Geomechanical Services and Innovations Inc.
- Bolter24 Sep 2026US 2026/0286845 A1Joy Global Underground Mining LLC
- Rock bolt17 Sep 2026US 2026/0275866 A1Sandvik Mining and Construction Australia (Production/Supply) Pty Ltd
- Drill Head Injection System for a Self-Drilling Rock Bolt Assembly10 Sep 2026US 2026/0266179 A1Oka Rock Bolt Technologies Pty Limited
- Rock bolt13 Aug 2026US 2026/0235029 A1Sandvik Mining and Construction Australia (Production/Supply) Pty Ltd
Most cited
By later US patents
- Method of rock bolting and rock bolt122US 4,511,289 AAtlas Copco Aktiebolag · 1985
- Method and installation apparatus for rock bolting121US 4,423,986 AAtlas Copco Aktiebolag · 1984
- Method of rock bolting and tube-formed expansion bolt114US 4,634,317 AAtlas Copco Aktiebolag · 1987
- Process, anchoring member, and clamping device for clamping a rod111US 5,022,791 AH. Weidmann AG · 1991
- Rock bolt system and method of rock bolting108US 5,335,736 ACommonwealth Scientific and Industrial Research Organisation · 1994