H04R 21/021
With granular resistance material
Official title: {with granular resistance material}
H04R21/021 (With granular resistance material) appears on 1 US grants and 0 published applications in this corpus.
Search patents in H04R- Granted patents
- 1
- Published applications
- 0
- Assignees
- 1
- Inventors
- 1
- Latest grant
- 27 Feb 1979
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1979 | 1 | 0 |
By publication year. Applications have been published since 2001.
Recent patents
No published applications in this class yet.
Most cited
By later US patents