Issued Patents 1989
Showing 1–1 of 1 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4831778 | Upper window sash with projections for simplified sash installation and removal | Dietrich Schmidt, David Johnson | 1989-05-23 |
Showing 1–1 of 1 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4831778 | Upper window sash with projections for simplified sash installation and removal | Dietrich Schmidt, David Johnson | 1989-05-23 |