Issued Patents 1989
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4889542 | Computer air filter device and method | — | 1989-12-26 |
| 4880477 | Process of making an austempered ductile iron article | Harry A. Matrone, Philip D. Johnson | 1989-11-14 |
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4889542 | Computer air filter device and method | — | 1989-12-26 |
| 4880477 | Process of making an austempered ductile iron article | Harry A. Matrone, Philip D. Johnson | 1989-11-14 |