Issued Patents 1994
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5347193 | Spark plug having an erosion resistant tip | Takafumi Oshima, Tsutomu Okayama | 1994-09-13 |
| 5320569 | Method of making a spark plug | Takafumi Oshima, Mamoru Musasa, Tsutomu Okayama | 1994-06-14 |