F04B 31/00
Free-piston pumps specially adapted for elastic fluids
Official title: Free-piston pumps specially adapted for elastic fluids; Systems incorporating such pumps (muscle-driven pumps in which the stroke is not defined by gearing F04B33/00)
F04B31/00 (Free-piston pumps specially adapted for elastic fluids) appears on 39 US grants and 42 published applications in this corpus.
Search patents in F04B- Granted patents
- 39
- Published applications
- 42
- Assignees
- 33
- Inventors
- 77
- Latest grant
- 5 May 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 1 | 0 |
| 1977 | 0 | 0 |
| 1978 | 0 | 0 |
| 1979 | 1 | 0 |
| 1980 | 2 | 0 |
| 1981 | 1 | 0 |
| 1982 | 0 | 0 |
| 1983 | 0 | 0 |
| 1984 | 1 | 0 |
| 1985 | 0 | 0 |
| 1986 | 0 | 0 |
| 1987 | 0 | 0 |
| 1988 | 1 | 0 |
| 1989 | 0 | 0 |
| 1990 | 0 | 0 |
| 1991 | 0 | 0 |
| 1992 | 0 | 0 |
| 1993 | 1 | 0 |
| 1994 | 0 | 0 |
| 1995 | 0 | 0 |
| 1996 | 1 | 0 |
| 1997 | 0 | 0 |
| 1998 | 2 | 0 |
| 1999 | 0 | 0 |
| 2000 | 0 | 0 |
| 2001 | 0 | 0 |
| 2002 | 0 | 1 |
| 2003 | 1 | 0 |
| 2004 | 0 | 1 |
| 2005 | 1 | 3 |
| 2006 | 0 | 2 |
| 2007 | 0 | 1 |
| 2008 | 1 | 0 |
| 2009 | 1 | 1 |
| 2010 | 0 | 0 |
| 2011 | 0 | 0 |
| 2012 | 1 | 0 |
| 2013 | 0 | 1 |
| 2014 | 1 | 1 |
| 2015 | 0 | 2 |
| 2016 | 0 | 3 |
| 2017 | 2 | 5 |
| 2018 | 3 | 6 |
| 2019 | 5 | 2 |
| 2020 | 4 | 2 |
| 2021 | 1 | 4 |
| 2022 | 2 | 0 |
| 2023 | 0 | 2 |
| 2024 | 2 | 3 |
| 2025 | 1 | 0 |
| 2026 | 2 | 2 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Recent patents
- Gas propulsion thrust device5 May 2026US 12,618,418 B1
- Compresser for pumping fluid having check valves aligned with fluid ports10 Mar 2026US 12,571,383 B2I-Jack Technologies Incorporated
- Device for transferring heat from a gaseous working medium29 Jul 2025US 12,372,307 B2RIMACOMP—GmbH
- Mechanical refrigeration system27 Feb 2024US 11,913,688 B2Off Technologies Stp, S.L.
- Refrigeration apparatus and operating method thereof20 Feb 2024US 11,906,206 B2Turboalgor S.R.L.
- Gas propulsion thrust device1 Oct 2026US 2026/0298134 A1
- Method for operating a linear motor compressor, and linear motor compressor13 Aug 2026US 2026/0235117 A1Burckhardt Compression AG
- Device for regulating the pressure and/or temperature of the refrigerant fluid entering a compressor of a refrigeration apparatus, respective refrigeration apparatus and method for operating said regulation device28 Nov 2024US 2024/0393021 A1Turboalgor S.R.L.
- Tire air filling device14 Nov 2024US 2024/0375460 A1Murakami Corporation
- Device for Transferring Heat from a Gaseous Working Medium29 Feb 2024US 2024/0068751 A1RIMACOMP—GmbH
Most cited
By later US patents
- Gas compressor95US 5,771,693 ANational Power PLC · 1998
- Method and apparatus for compressing a gas to a high pressure48US 7,527,482 B2Westport Power Inc. · 2009
- High pressure gas compressor38US 5,807,083 A1998
- Fluid power supply system28US 4,205,638 A1980
- Cooled spool piston compressor26US 5,238,372 AThe United States of America as represented by the Administrator of the National Aeronautics and Space Administration · 1993