Issued Patents All Time
Showing 1–3 of 3 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5156220 | Well tool with sealing means | Douglas J. Murray, Mark E. Hopmann, Ronald D. Williams | 1992-10-20 |
| 4953622 | Subterranean well casing float tool | Douglas J. Lehr, Merle L. Bell, Richard P. Rubbo | 1990-09-04 |
| 4872510 | Subterranean well casing float tool | Douglas J. Lehr, Merle L. Bell, Richard P. Rubbo | 1989-10-10 |