Issued Patents 1989
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4824237 | Vision and hand/eye coordination exercising and testing machine | Ronald Ratner, Glenn A. Seifert, Stephen Selwyn, Marvin Zaro | 1989-04-25 |
| 4796883 | Method and apparatus for juggling | — | 1989-01-10 |