Issued Patents All Time
Showing 51–54 of 54 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5044443 | Method and apparatus for producing wells | Ronald K. Churchman | 1991-09-03 |
| 4945993 | Surface controlled subsurface safety valve | Rennie L. Dickson | 1990-08-07 |
| 4723606 | Surface controlled subsurface safety valve | Michael B. Vinzant, Phillip S. Sizer, Ronald K. Churchman, Rennie L. Dickson | 1988-02-09 |
| 4624315 | Subsurface safety valve with lock-open system | Rennie L. Dickson | 1986-11-25 |