Issued Patents 1989
Showing 1–4 of 4 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4878464 | Pneumatic bistable electronic valve actuator | William E. Richeson | 1989-11-07 |
| 4875441 | Enhanced efficiency valve actuator | William E. Richeson | 1989-10-24 |
| 4872425 | Air powered valve actuator | William E. Richeson | 1989-10-10 |
| 4852528 | Pneumatic actuator with permanent magnet control valve latching | William E. Richeson | 1989-08-01 |