Issued Patents All Time
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4658121 | Self regulating heating device employing positive temperature coefficient of resistance compositions | David A. Horsma | 1987-04-14 |
| 4560498 | Positive temperature coefficient of resistance compositions | David A. Horsma | 1985-12-24 |