Issued Patents All Time
Showing 1–5 of 5 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4770721 | Process of treating steel for a vehicle suspension spring to improve sag-resistance | Toshiro Yamamoto, Ryohei KOBAYASHI, Toshio Ozone | 1988-09-13 |
| 4711675 | Process for improving the sag-resistance and hardenability of a spring steel | Toshiro Yamamoto, Ryohei KOBAYASHI, Toshio Ozone | 1987-12-08 |
| 4574016 | Method of treating steel for a vehicle suspension spring having a good sag-resistance | Toshiro Yamamoto, Ryohei KOBAYASHI, Toshio Ozone | 1986-03-04 |
| 4544406 | Spring steel having a good sag-resistance and a good hardenability | Toshiro Yamamoto, Ryohei KOBAYASHI, Toshio Ozone | 1985-10-01 |
| 4448617 | Steel for a vehicle suspension spring having good sag-resistance | Toshiro Yamamoto, Ryohei KOBAYASHI, Toshio Ozone | 1984-05-15 |