Issued Patents 1989
Showing 1–3 of 3 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4880443 | Molecular sieve oxygen concentrator with secondary oxygen purifier | Clarence F. Theis | 1989-11-14 |
| 4813979 | Secondary oxygen purifier for molecular sieve oxygen concentrator | Clarence F. Theis | 1989-03-21 |
| 4802991 | Method and apparatus for water purification | — | 1989-02-07 |