F04C 18/00
Rotary-piston pumps specially adapted for elastic fluids
Official title: Rotary-piston pumps specially adapted for elastic fluids (with fluid ring or the like F04C19/00; rotary-piston pumps in which the working-fluid is exclusively displaced by one or more reciprocating pistons F04B)
F04C18/00 (Rotary-piston pumps specially adapted for elastic fluids) appears on 5,895 US grants and 5,937 published applications in this corpus.
Search patents in F04C- Granted patents
- 5,895
- Published applications
- 5,937
- Assignees
- 1,093
- Inventors
- 7,390
- Latest grant
- 6 Oct 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 15 | 0 |
| 1977 | 12 | 0 |
| 1978 | 16 | 0 |
| 1979 | 9 | 0 |
| 1980 | 15 | 0 |
| 1981 | 9 | 0 |
| 1982 | 12 | 0 |
| 1983 | 15 | 0 |
| 1984 | 38 | 0 |
| 1985 | 38 | 0 |
| 1986 | 33 | 0 |
| 1987 | 37 | 0 |
| 1988 | 34 | 0 |
| 1989 | 42 | 0 |
| 1990 | 44 | 0 |
| 1991 | 65 | 0 |
| 1992 | 66 | 0 |
| 1993 | 54 | 0 |
| 1994 | 72 | 0 |
| 1995 | 59 | 0 |
| 1996 | 77 | 0 |
| 1997 | 67 | 0 |
| 1998 | 74 | 0 |
| 1999 | 46 | 0 |
| 2000 | 114 | 0 |
| 2001 | 146 | 43 |
| 2002 | 145 | 146 |
| 2003 | 137 | 155 |
| 2004 | 120 | 187 |
| 2005 | 102 | 194 |
| 2006 | 121 | 209 |
| 2007 | 119 | 151 |
| 2008 | 96 | 219 |
| 2009 | 113 | 217 |
| 2010 | 120 | 263 |
| 2011 | 142 | 216 |
| 2012 | 189 | 198 |
| 2013 | 160 | 223 |
| 2014 | 169 | 250 |
| 2015 | 199 | 284 |
| 2016 | 192 | 278 |
| 2017 | 219 | 295 |
| 2018 | 243 | 294 |
| 2019 | 251 | 293 |
| 2020 | 243 | 327 |
| 2021 | 269 | 285 |
| 2022 | 319 | 278 |
| 2023 | 248 | 266 |
| 2024 | 371 | 231 |
| 2025 | 257 | 237 |
| 2026 | 142 | 198 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Subgroups
Granted patents
- F04C 18/02Rotary-piston pumps specially adapted for elastic fluids: of arcuate-engagement type, i.e. with3,088
- F04C 18/08Rotary-piston pumps specially adapted for elastic fluids: of intermeshing-engagement type, i.e. with1,620
- F04C 18/30Rotary-piston pumps specially adapted for elastic fluids: having the characteristics covered by1,293
- F04C 18/48Rotary-piston pumps with non-parallel axes of movement of co-operating members111
- F04C 18/22Rotary-piston pumps specially adapted for elastic fluids: of internal-axis type with equidirectional57
- F04C 18/24Rotary-piston pumps specially adapted for elastic fluids: of counter-engagement type, i.e. the8
Recent patents
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Most cited
By later US patents
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- Portable ventilator system278US 7,188,621 B2Pulmonetic Systems, Inc. · 2007
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