Issued Patents 1989
Showing 1–4 of 4 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4890266 | Acoustic range finding system | — | 1989-12-26 |
| 4885773 | Apparatus for mounting a unidirectional microphone in a hands-free telephone subset | William O. Stottlemyer | 1989-12-05 |
| 4831565 | Process control equipment for adverse environments | — | 1989-05-16 |
| 4821215 | Monitoring equipment for adverse environments | — | 1989-04-11 |