F02B 25/08
Engines with oppositely-moving reciprocating working pistons
F02B25/08 (Engines with oppositely-moving reciprocating working pistons) appears on 170 US grants and 152 published applications in this corpus.
Search patents in F02B- Granted patents
- 170
- Published applications
- 152
- Assignees
- 43
- Inventors
- 174
- Latest grant
- 23 Sep 2025
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 1 | 0 |
| 1977 | 2 | 0 |
| 1978 | 2 | 0 |
| 1979 | 0 | 0 |
| 1980 | 2 | 0 |
| 1981 | 7 | 0 |
| 1982 | 4 | 0 |
| 1983 | 1 | 0 |
| 1984 | 1 | 0 |
| 1985 | 1 | 0 |
| 1986 | 0 | 0 |
| 1987 | 1 | 0 |
| 1988 | 0 | 0 |
| 1989 | 1 | 0 |
| 1990 | 0 | 0 |
| 1991 | 2 | 0 |
| 1992 | 3 | 0 |
| 1993 | 1 | 0 |
| 1994 | 1 | 0 |
| 1995 | 1 | 0 |
| 1996 | 3 | 0 |
| 1997 | 1 | 0 |
| 1998 | 1 | 0 |
| 1999 | 0 | 0 |
| 2000 | 1 | 0 |
| 2001 | 6 | 0 |
| 2002 | 0 | 0 |
| 2003 | 1 | 3 |
| 2004 | 3 | 0 |
| 2005 | 1 | 2 |
| 2006 | 0 | 4 |
| 2007 | 3 | 4 |
| 2008 | 2 | 4 |
| 2009 | 5 | 3 |
| 2010 | 0 | 3 |
| 2011 | 1 | 9 |
| 2012 | 2 | 14 |
| 2013 | 9 | 9 |
| 2014 | 10 | 10 |
| 2015 | 10 | 10 |
| 2016 | 11 | 21 |
| 2017 | 10 | 13 |
| 2018 | 17 | 9 |
| 2019 | 12 | 10 |
| 2020 | 7 | 6 |
| 2021 | 6 | 6 |
| 2022 | 8 | 3 |
| 2023 | 1 | 4 |
| 2024 | 5 | 4 |
| 2025 | 3 | 0 |
| 2026 | 0 | 1 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Subgroups
Granted patents
Recent patents
- High-efficiency linear generator23 Sep 2025US 12,421,890 B2Mainspring Energy, Inc.
- Hydrogen opposed-piston engine24 Jun 2025US 12,338,763 B2Achates Power, Inc.
- Opposed-piston engine17 Jun 2025US 12,331,675 B2Mitsubishi Heavy Industries, Ltd.
- Opposed-piston engine1 Oct 2024US 12,104,525 B2Mitsubishi Heavy Industries, Ltd.
- Exhaust catalyst light-off in an opposed-piston engine6 Aug 2024US 12,055,111 B2Achates Power, Inc.
- Two stroke apposed pistons parallel cylinders internal combustion engine1 Oct 2026US 2026/0298132 A1
- High-efficiency linear generator29 Aug 2024US 2024/0287930 A1Mainspring Energy, Inc.
- Hydrogen opposed-piston engine4 Jul 2024US 2024/0218826 A1Achates Power, Inc.
- Opposed-piston engine9 May 2024US 2024/0151177 A1Mitsubishi Heavy Industries, Ltd.
- Exhuast catalyst light-off in an opposed-piston engine22 Feb 2024US 2024/0060455 A1Achates Power, Inc.
Most cited
By later US patents
- Internal combustion engine with a single crankshaft and having opposed cylinders with opposed pistons130US 6,170,443 B22001
- Two-stroke diesel engine55US 6,182,619 B2General Atomics Aeronautical Systems, Inc. · 2001
- Dual compression and dual expansion engine51US 5,623,894 ACaterpillar Inc. · 1997
- Internal combustion engine50US 7,469,664 B2Advanced Propulsion Technologies, Inc. · 2008
- I.C. engine having improved air or air-fuel induction system44US 4,090,479 A1978