Issued Patents All Time
Showing 1–3 of 3 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5211398 | Hollow tennis racket frame with matched frequency of vibration | Masanori Takatsuka | 1993-05-18 |
| 4858928 | Racket frame | Kunimasa Muroi, Yoshinari Inagaki | 1989-08-22 |
| 4744562 | String protector for a racket | — | 1988-05-17 |