F01L 23/00
Valves controlled by impact by piston
Official title: Valves controlled by impact by piston, e.g. in free-piston machines
F01L23/00 (Valves controlled by impact by piston) appears on 123 US grants and 17 published applications in this corpus.
Search patents in F01L- Granted patents
- 123
- Published applications
- 17
- Assignees
- 53
- Inventors
- 157
- Latest grant
- 4 Nov 2025
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 6 | 0 |
| 1977 | 8 | 0 |
| 1978 | 9 | 0 |
| 1979 | 4 | 0 |
| 1980 | 6 | 0 |
| 1981 | 2 | 0 |
| 1982 | 7 | 0 |
| 1983 | 2 | 0 |
| 1984 | 3 | 0 |
| 1985 | 4 | 0 |
| 1986 | 2 | 0 |
| 1987 | 7 | 0 |
| 1988 | 6 | 0 |
| 1989 | 4 | 0 |
| 1990 | 4 | 0 |
| 1991 | 5 | 0 |
| 1992 | 8 | 0 |
| 1993 | 2 | 0 |
| 1994 | 5 | 0 |
| 1995 | 3 | 0 |
| 1996 | 5 | 0 |
| 1997 | 1 | 0 |
| 1998 | 1 | 0 |
| 1999 | 0 | 0 |
| 2000 | 0 | 0 |
| 2001 | 2 | 0 |
| 2002 | 2 | 0 |
| 2003 | 1 | 1 |
| 2004 | 0 | 1 |
| 2005 | 1 | 0 |
| 2006 | 0 | 0 |
| 2007 | 0 | 0 |
| 2008 | 0 | 1 |
| 2009 | 0 | 2 |
| 2010 | 1 | 2 |
| 2011 | 0 | 1 |
| 2012 | 1 | 1 |
| 2013 | 0 | 1 |
| 2014 | 2 | 2 |
| 2015 | 1 | 0 |
| 2016 | 2 | 0 |
| 2017 | 2 | 2 |
| 2018 | 0 | 1 |
| 2019 | 1 | 1 |
| 2020 | 2 | 0 |
| 2021 | 0 | 0 |
| 2022 | 0 | 0 |
| 2023 | 0 | 0 |
| 2024 | 0 | 0 |
| 2025 | 1 | 1 |
By publication year. Applications have been published since 2001.
Recent patents
- Operating engine4 Nov 2025US 12,460,547 B2
- High efficiency steam engine15 Sep 2020US 10,774,645 B1Thermal Power Recovery LLC
- High efficiency steam engine having improved steam cutoff control4 Feb 2020US 10,550,737 B2Thermal Power Recovery LLC
- Air motor and pump comprising such a motor20 Aug 2019US 10,385,693 B2Exel Industries
- High efficiency steam engine and steam expander28 Nov 2017US 9,828,886 B1Thermal Power Recovery LLC
- Operating engine16 Jan 2025US 2025/0020060 A1
- Unitary actuator valve for downhole operations14 Feb 2019US 2019/0048684 A1Baker Hughes, A Ge Company, LLC
- High efficiency steam engine having improved steam cutoff control9 Aug 2018US 2018/0223703 A1Thermal Power Recovery LLC
- Air motor and pump comprising such a motor7 Dec 2017US 2017/0350247 A1Exel Industries
- An air motor11 May 2017US 2017/0130581 A1
Most cited
By later US patents
- Reciprocable device with switching mechanism51US 5,505,593 AShurflo Pump Manufacturing Co. · 1996
- Device for producing an artificial blood circulation44US 4,212,589 A1980
- Double-acting diaphragm pump and reversing mechanism therefor43US 4,682,937 AThe Coca-Cola Company · 1987
- Continuously operating piston pump39US 3,999,896 A1976
- Air valve actuator for reciprocable machine38US 5,240,390 AGraco Inc. · 1993