Issued Patents All Time
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4360064 | Circulating valve for wells | John A. O'Connor, Warren E. Holland, Ronald D. Rogers, Fred E. Watkins, Ben D. Terral | 1982-11-23 |
| 4204690 | Sealing retaining ring assembly | Warren E. Holland, Henry P. Arendt | 1980-05-27 |