E21B 7/28
Enlarging drilled holes
Official title: Enlarging drilled holes, e.g. by counterboring
E21B7/28 (Enlarging drilled holes) appears on 689 US grants and 491 published applications in this corpus.
Search patents in E21B- Granted patents
- 689
- Published applications
- 491
- Assignees
- 246
- Inventors
- 886
- Latest grant
- 7 Jul 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 7 | 0 |
| 1977 | 14 | 0 |
| 1978 | 12 | 0 |
| 1979 | 7 | 0 |
| 1980 | 12 | 0 |
| 1981 | 12 | 0 |
| 1982 | 6 | 0 |
| 1983 | 14 | 0 |
| 1984 | 6 | 0 |
| 1985 | 9 | 0 |
| 1986 | 1 | 0 |
| 1987 | 9 | 0 |
| 1988 | 13 | 0 |
| 1989 | 8 | 0 |
| 1990 | 6 | 0 |
| 1991 | 10 | 0 |
| 1992 | 10 | 0 |
| 1993 | 10 | 0 |
| 1994 | 13 | 0 |
| 1995 | 8 | 0 |
| 1996 | 7 | 0 |
| 1997 | 7 | 0 |
| 1998 | 11 | 0 |
| 1999 | 10 | 0 |
| 2000 | 12 | 0 |
| 2001 | 14 | 3 |
| 2002 | 11 | 11 |
| 2003 | 8 | 11 |
| 2004 | 12 | 17 |
| 2005 | 6 | 10 |
| 2006 | 10 | 10 |
| 2007 | 10 | 15 |
| 2008 | 14 | 16 |
| 2009 | 7 | 12 |
| 2010 | 16 | 18 |
| 2011 | 13 | 14 |
| 2012 | 11 | 14 |
| 2013 | 13 | 20 |
| 2014 | 18 | 33 |
| 2015 | 16 | 29 |
| 2016 | 22 | 29 |
| 2017 | 34 | 32 |
| 2018 | 16 | 28 |
| 2019 | 35 | 36 |
| 2020 | 39 | 26 |
| 2021 | 31 | 25 |
| 2022 | 31 | 27 |
| 2023 | 18 | 17 |
| 2024 | 22 | 14 |
| 2025 | 18 | 14 |
| 2026 | 10 | 10 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Subgroups
Granted patents
Recent patents
- Combination shear and gouging cutting element and well construction tools made therewith7 Jul 2026US 12,674,362 B2Shear Bits, Ltd.
- Reverse circulation jet pump and reaming stabilizer26 May 2026US 12,637,914 B2
- Advanced inground operations, system and associated apparatus26 May 2026US 12,637,940 B2Merlin Technology, Inc.
- Pullback system for drilling tool7 Apr 2026US 12,595,703 B2Vermeer Manufacturing Company
- Expanding drill device10 Mar 2026US 12,571,263 B2Herrenknecht AG
- Wellbore controllable chamber-forming granular-flow mining system6 Aug 2026US 2026/0226817 A1Blueland Technology Limited
- Pullback system for drilling tool16 Jul 2026US 2026/0201752 A1Vermeer Manufacturing Company
- Earth boring reamer9 Jul 2026US 2026/0193941 A1Orvil Technologies, LLC
- Reamer for horizontal directional drilling18 Jun 2026US 2026/0168332 A1Michels Corporation
- Control system for horizontal directional drill30 Apr 2026US 2026/0117593 A1Vermeer Manufacturing Company
Most cited
By later US patents
- Method and apparatus for conversion of coal in situ366US 4,776,638 AUniversity of Kentucky Research Foundation · 1988
- Method and apparatus for replacing buried pipe209US 4,507,019 AExpand-A-Line, Incorporated · 1985
- Horizontal directional drilling machine employing inertial navigation control system and method190US 6,315,062 B1Vermeer Manufacturing Company · 2001
- Pipe splitting and spreading system147US 5,439,320 A1995
- Horizontal directional drilling machine and method employing configurable tracking system interface143US 6,484,818 B2Vermeer Manufacturing Company · 2002