Issued Patents 1989
Showing 1–3 of 3 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4857792 | Circular direction vibrator | Susumu Ishizuka, Setsuo Kojima | 1989-08-15 |
| 4811592 | Specific gravity detector | Susumu Ishizuka | 1989-03-14 |
| 4811593 | Viscosity detector | Susumu Ishizuka | 1989-03-14 |