Issued Patents 1989
Showing 1–1 of 1 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4839037 | Tapered, spirally wound filter cartridge and method of making same | Robert A. Bertelsen | 1989-06-13 |
Showing 1–1 of 1 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4839037 | Tapered, spirally wound filter cartridge and method of making same | Robert A. Bertelsen | 1989-06-13 |