Issued Patents All Time
Showing 26–28 of 28 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5355959 | Differential pressure operated circulating and deflation valve | Jeffrey S. Walter, John C. Zimmerman | 1994-10-18 |
| 4962815 | Inflatable straddle packer | Roger L. Schultz | 1990-10-16 |
| 4932471 | Downhole tool, including shock absorber | Stephen E. Tilghman | 1990-06-12 |