F01C 21/18
Arrangements for admission or discharge of the working fluid
Official title: Arrangements for admission or discharge of the working fluid, e.g. constructional features of the inlet or outlet
F01C21/18 (Arrangements for admission or discharge of the working fluid) appears on 230 US grants and 197 published applications in this corpus.
Search patents in F01C- Granted patents
- 230
- Published applications
- 197
- Assignees
- 118
- Inventors
- 411
- Latest grant
- 22 Sep 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 14 | 0 |
| 1977 | 8 | 0 |
| 1978 | 5 | 0 |
| 1979 | 1 | 0 |
| 1980 | 4 | 0 |
| 1981 | 2 | 0 |
| 1982 | 7 | 0 |
| 1983 | 4 | 0 |
| 1984 | 2 | 0 |
| 1985 | 3 | 0 |
| 1986 | 1 | 0 |
| 1987 | 2 | 0 |
| 1988 | 5 | 0 |
| 1989 | 1 | 0 |
| 1990 | 0 | 0 |
| 1991 | 0 | 0 |
| 1992 | 1 | 0 |
| 1993 | 0 | 0 |
| 1994 | 2 | 0 |
| 1995 | 2 | 0 |
| 1996 | 1 | 0 |
| 1997 | 1 | 0 |
| 1998 | 4 | 0 |
| 1999 | 1 | 0 |
| 2000 | 2 | 0 |
| 2001 | 2 | 0 |
| 2002 | 1 | 2 |
| 2003 | 2 | 1 |
| 2004 | 2 | 1 |
| 2005 | 2 | 7 |
| 2006 | 2 | 1 |
| 2007 | 0 | 0 |
| 2008 | 0 | 2 |
| 2009 | 1 | 3 |
| 2010 | 3 | 8 |
| 2011 | 1 | 7 |
| 2012 | 4 | 8 |
| 2013 | 3 | 16 |
| 2014 | 12 | 11 |
| 2015 | 12 | 21 |
| 2016 | 10 | 18 |
| 2017 | 15 | 18 |
| 2018 | 15 | 14 |
| 2019 | 11 | 10 |
| 2020 | 18 | 9 |
| 2021 | 8 | 8 |
| 2022 | 11 | 10 |
| 2023 | 5 | 5 |
| 2024 | 11 | 7 |
| 2025 | 4 | 8 |
| 2026 | 2 | 2 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Subgroups
Granted patents
Recent patents
- Two-stroke rotary engine with improved inlet and outlet ports22 Sep 2026US 12,742,390 B2LiquidPiston, Inc.
- Rotary piston machine3 Feb 2026US 12,540,572 B2
- Quieted front exhaust motor16 Dec 2025US 12,496,699 B2Ingersoll-Rand Industrial U.S., Inc.
- Rotational engine with inner and outer rings7 Oct 2025US 12,435,632 B2Duplicent, LLC
- Supercharger rotors for increased engine power output29 Jul 2025US 12,372,087 B2Brian Tooley Racing, Inc.
- Rotational Engine With Inner and Outer Rings17 Sep 2026US 2026/0275867 A1Duplicent, LLC
- Two-Stroke Rotary Engine with Improved Inlet and Outlet Ports19 Mar 2026US 2026/0078674 A1LiquidPiston, Inc.
- Rotary motor with integral fluid seal27 Nov 2025US 2025/0361808 A1Coool.Energy Ltd
- Supercharger rotors for increased engine power output20 Nov 2025US 2025/0354555 A1Brian Tooley Racing, Inc.
- Apparatus and Method Utilizing Energy Recovery Devices, Including in Fluid Separation Processes23 Oct 2025US 2025/0327435 A1Amorphic Tech Ltd
Most cited
By later US patents
- Rotary steam engine43US 4,047,856 A1977
- Rankine cycle device, expansion system and expansion machine41US 9,732,634 B2Panasonic Intellectual Property Management Co., Ltd. · 2017
- Fluid impulse torque tool30US 4,418,764 AGiken Kogyo Kabushiki Kaisha · 1983
- Air motor with offset front and rear exhausts28US 5,383,771 ASnap-on Incorporated · 1995
- Pneumatically operated rammer25US 5,340,233 AM-B-W Inc. · 1994