Issued Patents All Time
Showing 1–3 of 3 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5632334 | Heat recovery ventilator with room air defrosting feature | Peter Karl Grinbergs | 1997-05-27 |
| D376842 | Heat recovery ventilator | John C. Franklin, Peter Karl Grinbergs | 1996-12-24 |
| 4877318 | Ultra-short optical system for binoculars | John R. Miles, by Mildred L. Miles, heir | 1989-10-31 |