Issued Patents All Time
Showing 1–5 of 5 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| D297836 | Suspendable speaker | Philip H. Nelson | 1988-09-27 |
| D297011 | Plug-mounted background noise amplifier | Philip H. Nelson | 1988-08-02 |
| D280721 | Plug-mounted background noise amplifier enclosure | Philip H. Nelson | 1985-09-24 |
| D277956 | Speaker enclosure for raised floor installation | Philip H. Nelson | 1985-03-12 |
| 4450321 | Circuit for producing noise generation for sound masking | Philip H. Nelson | 1984-05-22 |