H04R 21/028
With a fluid as resistance material
Official title: {with a fluid as resistance material}
H04R21/028 (With a fluid as resistance material) appears on 4 US grants and 2 published applications in this corpus.
Search patents in H04R- Granted patents
- 4
- Published applications
- 2
- Assignees
- 4
- Inventors
- 10
- Latest grant
- 12 May 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1998 | 1 | 0 |
| 1999 | 0 | 0 |
| 2000 | 1 | 0 |
| 2001 | 0 | 0 |
| 2002 | 0 | 0 |
| 2003 | 0 | 0 |
| 2004 | 0 | 0 |
| 2005 | 0 | 0 |
| 2006 | 0 | 0 |
| 2007 | 0 | 0 |
| 2008 | 0 | 0 |
| 2009 | 0 | 0 |
| 2010 | 0 | 0 |
| 2011 | 0 | 0 |
| 2012 | 0 | 0 |
| 2013 | 0 | 0 |
| 2014 | 0 | 0 |
| 2015 | 0 | 1 |
| 2016 | 0 | 0 |
| 2017 | 1 | 0 |
| 2018 | 0 | 0 |
| 2019 | 0 | 0 |
| 2020 | 0 | 0 |
| 2021 | 0 | 0 |
| 2022 | 0 | 0 |
| 2023 | 0 | 1 |
| 2024 | 0 | 0 |
| 2025 | 0 | 0 |
| 2026 | 1 | 0 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Recent patents
- Vibration sensor12 May 2026US 12,627,916 B2Shenzhen Shokz Co., Ltd.
- Hydraulic microphone7 Mar 2017US 9,591,413 B2Cochlear Limited
- Fluid coupled subwoofer acoustic enclosure system11 Jan 2000US 6,014,448 ASound Related Technologies, Inc.
- Environmentally sealed acoustic transducer coupling17 Mar 1998US 5,729,508 ARosemount Aerospace Inc.
Most cited
By later US patents