Issued Patents All Time
Showing 1–4 of 4 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| RE37995 | Progressive cavity pump with flexible coupling | Steven K. Tetzlaff | 2003-02-18 |
| 5501580 | Progressive cavity pump with flexible coupling | Steven K. Tetzlaff | 1996-03-26 |
| 5253704 | High pressure automatic mud saver valve | Reginald J. Barrus, Theodore A. Kritikos, John Owensby | 1993-10-19 |
| 4969513 | High pressure automatic kelly valve | Reginald J. Barrus, Theodore A. Kritikos, John Owensby | 1990-11-13 |