Issued Patents 1989
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4827247 | Self-compensating projected-beam smoke detector | — | 1989-05-02 |
| 4823015 | Electrical interference free projected beam smoke detector | Aaron A. Galvin, Douglas L. Mason, Kenneth J. Leff, John N. Schide | 1989-04-18 |