F01N 1/023
Helmholtz resonators
Official title: {Helmholtz resonators}
F01N1/023 (Helmholtz resonators) appears on 209 US grants and 195 published applications in this corpus.
Search patents in F01N- Granted patents
- 209
- Published applications
- 195
- Assignees
- 142
- Inventors
- 497
- Latest grant
- 28 Oct 2025
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 1 | 0 |
| 1977 | 2 | 0 |
| 1978 | 1 | 0 |
| 1979 | 1 | 0 |
| 1980 | 2 | 0 |
| 1981 | 1 | 0 |
| 1982 | 1 | 0 |
| 1983 | 1 | 0 |
| 1984 | 1 | 0 |
| 1985 | 4 | 0 |
| 1986 | 2 | 0 |
| 1987 | 0 | 0 |
| 1988 | 0 | 0 |
| 1989 | 0 | 0 |
| 1990 | 1 | 0 |
| 1991 | 2 | 0 |
| 1992 | 0 | 0 |
| 1993 | 3 | 0 |
| 1994 | 4 | 0 |
| 1995 | 1 | 0 |
| 1996 | 1 | 0 |
| 1997 | 1 | 0 |
| 1998 | 2 | 0 |
| 1999 | 3 | 0 |
| 2000 | 5 | 0 |
| 2001 | 1 | 0 |
| 2002 | 6 | 4 |
| 2003 | 4 | 2 |
| 2004 | 2 | 3 |
| 2005 | 1 | 4 |
| 2006 | 0 | 3 |
| 2007 | 5 | 5 |
| 2008 | 3 | 3 |
| 2009 | 5 | 3 |
| 2010 | 1 | 8 |
| 2011 | 3 | 7 |
| 2012 | 5 | 7 |
| 2013 | 12 | 6 |
| 2014 | 7 | 6 |
| 2015 | 2 | 8 |
| 2016 | 6 | 13 |
| 2017 | 11 | 19 |
| 2018 | 11 | 10 |
| 2019 | 14 | 19 |
| 2020 | 9 | 22 |
| 2021 | 13 | 17 |
| 2022 | 19 | 8 |
| 2023 | 12 | 9 |
| 2024 | 9 | 5 |
| 2025 | 8 | 1 |
| 2026 | 0 | 3 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Recent patents
- Sound damper28 Oct 2025US 12,454,901 B2Purem GmbH
- Dual mode muffler21 Oct 2025US 12,448,907 B2Tenneco Automotive Operating Company Inc.
- Turbo-compounded engine with exhaust duct acoustic arrangement16 Sep 2025US 12,415,611 B2Pratt & Whitney Canada Corp.
- Sound reducer, method of making same, and fluid conduit system including such a sound reducer26 Aug 2025US 12,400,627 B2Umfotec GmbH
- Exhaust sound attenuation and control system20 May 2025US 12,305,546 B2
- Muffler for Noise Reduction of Heat Dissipation Fan in Computer System27 Aug 2026US 2026/0251159 A1Celanese Mercury Holdings Inc.
- Damping Device25 Jun 2026US 2026/0177182 A1Hydac Technology GmbH
- Turbo-compounded engine with exhaust duct acoustic arrangement19 Mar 2026US 2026/0077875 A1Pratt & Whitney Canada Corp.
- Dual Mode Muffler27 Feb 2025US 2025/0067201 A1Tenneco Automotive Operating Company Inc.
- Turbo-compounded engine with exhaust duct acoustic arrangement26 Dec 2024US 2024/0425192 A1Pratt & Whitney Canada Corp.
Most cited
By later US patents
- Straight through muffler with conically-ended output passage126US 6,158,546 ATenneco Automotive Inc. · 2000
- Noise attenuator for an induction system or an exhaust system55US 6,009,705 ATennex Europe Limited · 2000
- Exhaust silencer arrangement52US 6,158,214 AJ. Eberspächer GmbH & Co. KG · 2000
- Exhaust system for internal combustion engines51US 5,388,408 ALawrence-Keech Inc. · 1995
- Ceramic filter construction and method50US 5,250,094 ADonaldson Company, Inc. · 1993