Issued Patents 1989
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4862349 | Method for extracting and/or replacing control system information in a computer operating system | David Allan Hellenga, Richard K. Hill | 1989-08-29 |
| 4854349 | Sewage draining device for recreational vehicles or the like | — | 1989-08-08 |