F01B 11/00
Reciprocating-piston machines or engines without rotary main shaft
Official title: Reciprocating-piston machines or engines without rotary main shaft, e.g. of free-piston type
F01B11/00 (Reciprocating-piston machines or engines without rotary main shaft) appears on 329 US grants and 180 published applications in this corpus.
Search patents in F01B- Granted patents
- 329
- Published applications
- 180
- Assignees
- 146
- Inventors
- 479
- Latest grant
- 25 Aug 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 6 | 0 |
| 1977 | 4 | 0 |
| 1978 | 10 | 0 |
| 1979 | 15 | 0 |
| 1980 | 9 | 0 |
| 1981 | 9 | 0 |
| 1982 | 9 | 0 |
| 1983 | 11 | 0 |
| 1984 | 7 | 0 |
| 1985 | 3 | 0 |
| 1986 | 2 | 0 |
| 1987 | 3 | 0 |
| 1988 | 8 | 0 |
| 1989 | 12 | 0 |
| 1990 | 6 | 0 |
| 1991 | 5 | 0 |
| 1992 | 7 | 0 |
| 1993 | 7 | 0 |
| 1994 | 2 | 0 |
| 1995 | 3 | 0 |
| 1996 | 5 | 0 |
| 1997 | 2 | 0 |
| 1998 | 5 | 0 |
| 1999 | 7 | 0 |
| 2000 | 6 | 0 |
| 2001 | 2 | 0 |
| 2002 | 1 | 3 |
| 2003 | 4 | 5 |
| 2004 | 0 | 0 |
| 2005 | 7 | 1 |
| 2006 | 1 | 5 |
| 2007 | 2 | 0 |
| 2008 | 1 | 2 |
| 2009 | 1 | 5 |
| 2010 | 2 | 8 |
| 2011 | 1 | 4 |
| 2012 | 5 | 14 |
| 2013 | 9 | 11 |
| 2014 | 7 | 10 |
| 2015 | 7 | 7 |
| 2016 | 8 | 8 |
| 2017 | 16 | 19 |
| 2018 | 10 | 6 |
| 2019 | 9 | 18 |
| 2020 | 20 | 15 |
| 2021 | 10 | 7 |
| 2022 | 14 | 19 |
| 2023 | 14 | 4 |
| 2024 | 10 | 5 |
| 2025 | 3 | 3 |
| 2026 | 2 | 1 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Subgroups
Granted patents
- F01B 11/001In which the movement in the two directions is obtained by one91
- F01B 11/007In which the movement in only one direction is obtained by a58
- F01B 11/02Equalising or cushioning devices55
- F01B 11/004In which the movement in the two directions is obtained by two41
- F01B 11/04Engines combined with reciprocatory driven devices33
- F01B 11/08Reciprocating-piston machines or engines without rotary main shaft: with direct fluid transmission18
- F01B 11/009In which the movement in two directions is obtained by two or5
Recent patents
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- Integrated linear generator system17 Feb 2026US 12,556,063 B2Mainspring Energy, Inc.
- High-efficiency linear generator23 Sep 2025US 12,421,890 B2Mainspring Energy, Inc.
- Linear electrical machine1 Jul 2025US 12,348,115 B2Libertine FPE Ltd
- Control of piston trajectory in a linear generator28 Jan 2025US 12,209,548 B2Mainspring Energy, Inc.
- Electric Power Generating Apparatus And Method Of Operating Same28 May 2026US 2026/0149396 A1NovoPower International Inc.
- Linear electrical machine16 Oct 2025US 2025/0323553 A1Libertine FPE Ltd
- Integrated linear generator system22 May 2025US 2025/0167632 A1Mainspring Energy, Inc.
- Integrated linear generator system23 Jan 2025US 2025/0030317 A1Mainspring Energy, Inc.
- High-power core system5 Sep 2024US 2024/0297553 A1Mainspring Energy, Inc.
Most cited
By later US patents
- Self-contained renewable energy system69US 4,776,171 APerry Oceanographics, Inc. · 1988
- Hydraulic intensifier63US 3,967,542 AKelsey-Hayes Company · 1976
- Reciprocable device with switching mechanism51US 5,505,593 AShurflo Pump Manufacturing Co. · 1996
- Free-piston regenerative hot gas hydraulic engine48US 4,215,548 AThe United States of America as represented by the Administrator of the National Aeronautics and Space Administration · 1980
- Internal combustion apparatus39US 4,377,991 AAnvar Agence Nationale de Valorisation de la Recherche · 1983