E04F 11/028
Having a central stringer
Official title: having a central stringer
E04F11/028 (Having a central stringer) appears on 11 US grants and 4 published applications in this corpus.
Search patents in E04F- Granted patents
- 11
- Published applications
- 4
- Assignees
- 5
- Inventors
- 13
- Latest grant
- 18 Mar 2025
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1978 | 1 | 0 |
| 1979 | 0 | 0 |
| 1980 | 0 | 0 |
| 1981 | 0 | 0 |
| 1982 | 1 | 0 |
| 1983 | 0 | 0 |
| 1984 | 0 | 0 |
| 1985 | 1 | 0 |
| 1986 | 0 | 0 |
| 1987 | 0 | 0 |
| 1988 | 0 | 0 |
| 1989 | 0 | 0 |
| 1990 | 0 | 0 |
| 1991 | 1 | 0 |
| 1992 | 1 | 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 | 1 |
| 2012 | 0 | 0 |
| 2013 | 0 | 0 |
| 2014 | 1 | 0 |
| 2015 | 2 | 1 |
| 2016 | 0 | 1 |
| 2017 | 0 | 0 |
| 2018 | 1 | 0 |
| 2019 | 1 | 0 |
| 2020 | 0 | 0 |
| 2021 | 0 | 0 |
| 2022 | 0 | 1 |
| 2023 | 0 | 0 |
| 2024 | 0 | 0 |
| 2025 | 1 | 0 |
By publication year. Applications have been published since 2001.
Recent patents
- Floating modular stair system18 Mar 2025US 12,252,886 B2PrimeSource Building Products, Inc.
- System and method for stair assembly and installation23 Jul 2019US 10,358,827 B1
- Open stair case with center uncut stringer26 Jun 2018US 10,006,207 B2
- Modular stairway15 Dec 2015US 9,212,491 B1
- Spiral box stair21 Jul 2015US 9,085,904 B2
Most cited
By later US patents