F28F 1/04
Polygonal
Official title: polygonal, e.g. rectangular {(F28F1/022 takes precedence)}
F28F1/04 (Polygonal) appears on 218 US grants and 314 published applications in this corpus.
Search patents in F28F- Granted patents
- 218
- Published applications
- 314
- Assignees
- 173
- Inventors
- 736
- Latest grant
- 1 Sep 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 1 | 0 |
| 1977 | 0 | 0 |
| 1978 | 2 | 0 |
| 1979 | 0 | 0 |
| 1980 | 5 | 0 |
| 1981 | 0 | 0 |
| 1982 | 2 | 0 |
| 1983 | 0 | 0 |
| 1984 | 2 | 0 |
| 1985 | 0 | 0 |
| 1986 | 2 | 0 |
| 1987 | 1 | 0 |
| 1988 | 0 | 0 |
| 1989 | 2 | 0 |
| 1990 | 2 | 0 |
| 1991 | 1 | 0 |
| 1992 | 1 | 0 |
| 1993 | 0 | 0 |
| 1994 | 2 | 0 |
| 1995 | 1 | 0 |
| 1996 | 1 | 0 |
| 1997 | 1 | 0 |
| 1998 | 2 | 0 |
| 1999 | 1 | 0 |
| 2000 | 2 | 0 |
| 2001 | 2 | 0 |
| 2002 | 3 | 6 |
| 2003 | 3 | 4 |
| 2004 | 2 | 10 |
| 2005 | 5 | 6 |
| 2006 | 6 | 6 |
| 2007 | 2 | 3 |
| 2008 | 5 | 8 |
| 2009 | 2 | 6 |
| 2010 | 1 | 11 |
| 2011 | 3 | 9 |
| 2012 | 3 | 8 |
| 2013 | 5 | 13 |
| 2014 | 1 | 9 |
| 2015 | 4 | 13 |
| 2016 | 5 | 19 |
| 2017 | 6 | 26 |
| 2018 | 16 | 15 |
| 2019 | 17 | 27 |
| 2020 | 12 | 20 |
| 2021 | 17 | 18 |
| 2022 | 19 | 18 |
| 2023 | 16 | 17 |
| 2024 | 8 | 22 |
| 2025 | 15 | 13 |
| 2026 | 9 | 7 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Subgroups
Granted patents
Recent patents
- Plate with flow channel1 Sep 2026US 12,723,816 B2NHK Spring Co., Ltd.
- Wastewater heat recovery systems28 Jul 2026US 12,693,080 B2Kohler Mira Limited
- Heat exchanger7 Jul 2026US 12,674,624 B2Zhejiang Dunan Artificial Environment Co., Ltd.
- Heat exchanger and refrigeration cycle apparatus23 Jun 2026US 12,663,222 B2Mitsubishi Electric Corporation
- Heat exchanger23 Jun 2026US 12,663,223 B2Daikin Industries, Ltd.
- Highly efficient and economical fluid flat tube structure24 Sep 2026US 2026/0287092 A1
- Heat exchanger24 Sep 2026US 2026/0287275 A1Daikin Industries, Ltd.
- Flow channel structure30 Jul 2026US 2026/0218995 A1Champ Tech Optical (Foshan) Corporation
- Tubular element for a heat exchanger18 Jun 2026US 2026/0168741 A1Valeo Systemes Thermiques
- Refrigeration apparatus19 Mar 2026US 2026/0078938 A1Daikin Industries, Ltd.
Most cited
By later US patents
- Method and apparatus for operating gas turbine engine heat exchangers71US 8,387,362 B22013
- Method of manufacturing a micro-passage plate fin heat exchanger69US 5,309,637 ARockwell International Corporation · 1994
- Heat exchanger for an electronic heat pump53US 6,619,044 B2Hydrocool Pyt, Limited · 2003
- Swirl flow heat exchanger with reverse spiral configuration51US 4,883,117 ASundstrand Corporation · 1989
- Combined heat exchanger reactor50US 4,101,287 AExxon Research & Engineering Co. · 1978