Issued Patents All Time
Showing 1–7 of 7 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| D348675 | Pay type telephone station volume control push-button switch | — | 1994-07-12 |
| D348471 | Pay type telephone station volume control push-button switch | — | 1994-07-05 |
| 5321584 | Battery and holder assembly for use with a battery operated touch pen | — | 1994-06-14 |
| 5315645 | Communication apparatus utilizing digital optical signals | — | 1994-05-24 |
| 4862494 | Anti-fraud device for use with a coin operated telephone instrument | — | 1989-08-29 |
| 4829561 | Apparatus for optically coupling a terminal unit to the public telephone network through a pay telephone instrument and the like | — | 1989-05-09 |
| 4773088 | Telephone amplifier with switchable gain control | — | 1988-09-20 |