Issued Patents 1989
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4854600 | Pressure balanced metallic S-seal | Horace P. Halling, Robert Alan Barrett | 1989-08-08 |
| 4813692 | Pressure balanced S-seal | Horace P. Halling, Robert Alan Barrett | 1989-03-21 |