E21B 4/08
Impact being obtained by gravity only
Official title: impact being obtained by gravity only, e.g. with lost-motion connection
E21B4/08 (Impact being obtained by gravity only) appears on 7 US grants and 1 published applications in this corpus.
Search patents in E21B- Granted patents
- 7
- Published applications
- 1
- Assignees
- 1
- Inventors
- 8
- Latest grant
- 30 Sep 2003
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1982 | 1 | 0 |
| 1983 | 1 | 0 |
| 1984 | 1 | 0 |
| 1985 | 0 | 0 |
| 1986 | 0 | 0 |
| 1987 | 0 | 0 |
| 1988 | 2 | 0 |
| 1989 | 0 | 0 |
| 1990 | 0 | 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 | 1 | 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 | 1 |
By publication year. Applications have been published since 2001.
Recent patents
- Assembly and method for jarring a drilling drive pipe into undersea formation30 Sep 2003US 6,626,248 B1Smith International, Inc.
- Multiple blow percussion drill assembly with rapid field maintenance and adjustment capability11 Jun 1991US 5,022,474 A
- Soil penetration and sampling system13 Sep 1988US 4,770,030 A
- Percussion drill string assembly1 Mar 1988US 4,727,944 A
- Gravity percussion drill with upper end cocking spring and method of assembly3 Apr 1984US 4,440,245 A
Most cited
By later US patents
- Soil penetration and sampling system14US 4,770,030 A1988
- Assembly and method for jarring a drilling drive pipe into undersea formation9US 6,626,248 B1Smith International, Inc. · 2003
- Well point and method of driving same4US 4,368,785 A1983
- Percussion drill string assembly3US 4,727,944 A1988
- Reciprocating drill bit2US 4,354,561 A1982