Issued Patents 1989
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4814665 | Center electrode structure for spark plug | Akio Sakura, Junichi Kagawa | 1989-03-21 |
| 4808135 | Center electrode structure for spark plug | Akio Sakura, Junichi Kagawa | 1989-02-28 |