E21D 9/0874
With rotary drilling heads having variable diameter
Official title: {with rotary drilling heads having variable diameter}
E21D9/0874 (With rotary drilling heads having variable diameter) appears on 3 US grants and 1 published applications in this corpus.
Search patents in E21D- Granted patents
- 3
- Published applications
- 1
- Assignees
- 10
- Inventors
- 16
- Latest grant
- 21 Jan 2020
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1990 | 1 | 0 |
| 1991 | 1 | 0 |
| 1992 | 0 | 0 |
| 1993 | 0 | 0 |
| 1994 | 0 | 0 |
| 1995 | 0 | 0 |
| 1996 | 0 | 0 |
| 1997 | 0 | 0 |
| 1998 | 0 | 0 |
| 1999 | 0 | 0 |
| 2000 | 0 | 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 | 0 |
| 2010 | 0 | 0 |
| 2011 | 0 | 0 |
| 2012 | 0 | 0 |
| 2013 | 0 | 0 |
| 2014 | 0 | 0 |
| 2015 | 0 | 0 |
| 2016 | 0 | 0 |
| 2017 | 0 | 0 |
| 2018 | 0 | 0 |
| 2019 | 0 | 1 |
| 2020 | 1 | 0 |
By publication year. Applications have been published since 2001.
Recent patents
- Tunnel boring machine21 Jan 2020US 10,539,016 B2Xcmg-Kaigong Heavy Industry Nanjing Co., Ltd
- Shield tunneling with optional section and machine12 Mar 1991US 4,998,776 AKabushiki Kaisha Kobe Seiko Sho
- Control system for synchronous rotation of cutter heads, for use in shield machine3 Jul 1990US 4,939,431 ADaiho Construction Co., Ltd.
Most cited
By later US patents
- Control system for synchronous rotation of cutter heads, for use in shield machine5US 4,939,431 ADaiho Construction Co., Ltd. · 1990
- Shield tunneling with optional section and machine3US 4,998,776 AKabushiki Kaisha Kobe Seiko Sho · 1991
- Tunnel boring machine1US 10,539,016 B2Xcmg-Kaigong Heavy Industry Nanjing Co., Ltd · 2020