Issued Patents All Time
Showing 1–6 of 6 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4588865 | Music on hold for key systems | — | 1986-05-13 |
| 4410765 | Telephone call routing and charging system | Harry O. Hansen | 1983-10-18 |
| 4346261 | Speaker phones | Levi L. Rose | 1982-08-24 |
| 4314107 | Subscriber station networks | Michael L. Tentler, Levi L. Rose | 1982-02-02 |
| 4278843 | Two-way amplifier arrangement | — | 1981-07-14 |
| 4232200 | Dialing system | Jan Synek, Harold O. Hansen | 1980-11-04 |