Issued Patents 1989
Showing 1–4 of 4 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4834196 | Well drilling tool | — | 1989-05-30 |
| 4811635 | Power tong improvement | — | 1989-03-14 |
| 4811798 | Drilling motor deviation tool | William N. Schoeffler | 1989-03-14 |
| 4807709 | Fluid Powered drilling jar | William N. Schoeffler | 1989-02-28 |