B43L 21/02
Blackboard or slate cleaning devices: with means for absorbing the chalk dust
Official title: with means for absorbing the chalk dust
B43L21/02 (Blackboard or slate cleaning devices: with means for absorbing the chalk dust) appears on 23 US grants and 10 published applications in this corpus.
Search patents in B43L- Granted patents
- 23
- Published applications
- 10
- Assignees
- 5
- Inventors
- 37
- Latest grant
- 9 Apr 2024
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 1 | 0 |
| 1977 | 0 | 0 |
| 1978 | 2 | 0 |
| 1979 | 0 | 0 |
| 1980 | 0 | 0 |
| 1981 | 0 | 0 |
| 1982 | 0 | 0 |
| 1983 | 0 | 0 |
| 1984 | 1 | 0 |
| 1985 | 1 | 0 |
| 1986 | 1 | 0 |
| 1987 | 0 | 0 |
| 1988 | 1 | 0 |
| 1989 | 0 | 0 |
| 1990 | 1 | 0 |
| 1991 | 0 | 0 |
| 1992 | 0 | 0 |
| 1993 | 1 | 0 |
| 1994 | 1 | 0 |
| 1995 | 1 | 0 |
| 1996 | 1 | 0 |
| 1997 | 0 | 0 |
| 1998 | 0 | 0 |
| 1999 | 0 | 0 |
| 2000 | 1 | 0 |
| 2001 | 2 | 0 |
| 2002 | 0 | 0 |
| 2003 | 0 | 3 |
| 2004 | 1 | 0 |
| 2005 | 2 | 0 |
| 2006 | 0 | 1 |
| 2007 | 0 | 1 |
| 2008 | 1 | 1 |
| 2009 | 0 | 0 |
| 2010 | 1 | 1 |
| 2011 | 1 | 2 |
| 2012 | 0 | 0 |
| 2013 | 1 | 0 |
| 2014 | 0 | 0 |
| 2015 | 0 | 0 |
| 2016 | 0 | 0 |
| 2017 | 0 | 0 |
| 2018 | 0 | 0 |
| 2019 | 0 | 0 |
| 2020 | 0 | 0 |
| 2021 | 0 | 0 |
| 2022 | 0 | 0 |
| 2023 | 0 | 0 |
| 2024 | 1 | 1 |
By publication year. Applications have been published since 2001.
Recent patents
- Blackboard eraser cleaner9 Apr 2024US 11,951,765 B1Zhejiang University
- Apparatus erasing blackboard through areas19 Feb 2013US 8,375,505 B2National Central University
- Eraser for blackboard12 Apr 2011US 7,921,501 B2
- Vacuum eraser for blackboards30 Mar 2010US 7,685,672 B2
- Chalk-dust collecting apparatus for blackboard eraser11 Nov 2008US 7,448,112 B2Global Metal Supplier Corp.
- Blackboard eraser cleaner2 May 2024US 2024/0140131 A1Zhejiang University
- Apparatus Erasing Blackboard through Areas7 Jul 2011US 2011/0162163 A1National Central University
- Multi-function board eraser structure30 Jun 2011US 2011/0154608 A1
- Eraser for Blackboard16 Dec 2010US 2010/0313381 A1
- Chalk-dust collecting apparatus for blackboard eraser3 Jul 2008US 2008/0155778 A1Global Metal Supplier Corp.
Most cited
By later US patents