F01N 3/021
By means of filters
Official title: by means of filters
F01N3/021 (By means of filters) appears on 6,628 US grants and 7,468 published applications in this corpus.
Search patents in F01N- Granted patents
- 6,628
- Published applications
- 7,468
- Assignees
- 1,128
- Inventors
- 9,935
- Latest grant
- 29 Sep 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 6 | 0 |
| 1977 | 4 | 0 |
| 1978 | 3 | 0 |
| 1979 | 3 | 0 |
| 1980 | 8 | 0 |
| 1981 | 18 | 0 |
| 1982 | 28 | 0 |
| 1983 | 31 | 0 |
| 1984 | 30 | 0 |
| 1985 | 42 | 0 |
| 1986 | 35 | 0 |
| 1987 | 43 | 0 |
| 1988 | 26 | 0 |
| 1989 | 48 | 0 |
| 1990 | 44 | 0 |
| 1991 | 57 | 0 |
| 1992 | 45 | 0 |
| 1993 | 54 | 0 |
| 1994 | 20 | 0 |
| 1995 | 40 | 0 |
| 1996 | 25 | 0 |
| 1997 | 28 | 0 |
| 1998 | 41 | 0 |
| 1999 | 35 | 0 |
| 2000 | 31 | 0 |
| 2001 | 33 | 20 |
| 2002 | 43 | 94 |
| 2003 | 55 | 156 |
| 2004 | 110 | 233 |
| 2005 | 117 | 259 |
| 2006 | 145 | 282 |
| 2007 | 156 | 358 |
| 2008 | 151 | 387 |
| 2009 | 196 | 418 |
| 2010 | 233 | 386 |
| 2011 | 257 | 425 |
| 2012 | 318 | 315 |
| 2013 | 344 | 333 |
| 2014 | 343 | 338 |
| 2015 | 362 | 404 |
| 2016 | 304 | 309 |
| 2017 | 343 | 416 |
| 2018 | 273 | 368 |
| 2019 | 389 | 383 |
| 2020 | 338 | 372 |
| 2021 | 347 | 306 |
| 2022 | 295 | 291 |
| 2023 | 267 | 207 |
| 2024 | 203 | 186 |
| 2025 | 187 | 121 |
| 2026 | 74 | 101 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Subgroups
Granted patents
- F01N 3/023Using means for regenerating the filters3,071
- F01N 3/033In combination with other devices2,614
- F01N 3/022Characterised by specially adapted filtering structure1,604
- F01N 3/031Having means for by-passing filters318
- F01N 3/0211Arrangements for mounting filtering elements in housing315
- F01N 3/0217The filtering elements having the form of hollow cylindrical bodies100
- F01N 3/0212With one or more perforated tubes surrounded by filtering material65
- F01N 3/0215The filtering elements having the form of disks or plates54
Recent patents
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Most cited
By later US patents
- Diesel particulate trap330US 4,329,162 ACorning Glass Works · 1982
- Radio frequency process sensing, control, and diagnostics network and system267US 10,118,119 B2CTS Corporation · 2018
- Device for removal of contaminants from fluid streams235US 5,750,026 ACorning Incorporated · 1998
- Treatment of diesel exhaust gases207US 4,902,487 AJohnson Matthey PLC · 1990
- Honeycomb filter and ceramic filter assembly201US 6,669,751 B1Ibiden Co., Ltd. · 2003