Issued Patents 1989
Showing 1–1 of 1 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4887558 | Internal-combustion engine having opposed integral annular pistons and a central shaft | — | 1989-12-19 |
Showing 1–1 of 1 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4887558 | Internal-combustion engine having opposed integral annular pistons and a central shaft | — | 1989-12-19 |