Issued Patents 1989
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4865382 | Surgeon's operating stool | — | 1989-09-12 |
| 4836302 | Apparatus and method for removing and recovering oil and/or other oil-based drilling mud additives from drill cuttings | Joe K. Heilhecker, Robert E. Williams | 1989-06-06 |