Issued Patents All Time
Showing 1–1 of 1 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4535972 | System to control the vertical movement of a drillstring | Keith K. Millheim | 1985-08-20 |
Showing 1–1 of 1 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4535972 | System to control the vertical movement of a drillstring | Keith K. Millheim | 1985-08-20 |