Issued Patents All Time
Showing 1–3 of 3 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4536624 | Telephone answering machine interface circuit | — | 1985-08-20 |
| 4499335 | Announcement recording and message playback system for a telephone answering machine | — | 1985-02-12 |
| 4484036 | Telephone ring detector system | Bradford E. Hanscom | 1984-11-20 |