Issued Patents All Time
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5204579 | Ceramic insulator for spark plug structure | Takafumi Oshima, Shigeyasu Yamada | 1993-04-20 |
| 4949006 | Spark plug structure | Takafumi Oshima, Shigeyasu Yamada | 1990-08-14 |