Issued Patents 1989
Showing 1–1 of 1 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4854953 | Air filter and module to be used for building up such a filter | Johannes Valkenburg, Ferdinand P. van der Spek | 1989-08-08 |
Showing 1–1 of 1 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4854953 | Air filter and module to be used for building up such a filter | Johannes Valkenburg, Ferdinand P. van der Spek | 1989-08-08 |