Issued Patents 1989
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4870992 | Backflow prevention device | Frank R. Irwin | 1989-10-03 |
| 4816957 | Ground line fault interrupter adapter unit | — | 1989-03-28 |
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4870992 | Backflow prevention device | Frank R. Irwin | 1989-10-03 |
| 4816957 | Ground line fault interrupter adapter unit | — | 1989-03-28 |