Issued Patents 1989
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4876436 | PTC air heater employing triangular PTC heating elements | Noel L. W. Lawrence, Lee A. Prager | 1989-10-24 |
| 4797534 | PTC thermistor heating device | Lee A. Prager | 1989-01-10 |