Issued Patents 1989
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4836931 | Reinforced filter tube and method of making the same | Michael R. Spearman, Patrick Richard Spearman | 1989-06-06 |
| 4814033 | Method of making a reinforced filter tube | Michael R. Spearman, Patrick Richard Spearman | 1989-03-21 |