Issued Patents All Time
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 6499910 | Method for applying guidelines for visually handicapped persons | Antonius Jacob Grahmbeek | 2002-12-31 |
| 6450728 | Paving tile for guidance of blind persons | Marit Astrid Grahmbeek | 2002-09-17 |