Issued Patents 1989
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4885573 | Diagnostic system for combustion controller | John J. Fry, George R. Hall, II | 1989-12-05 |
| 4837501 | Apparatus for measuring differential impedances | John J. Fry | 1989-06-06 |