Issued Patents All Time
Showing 1–3 of 3 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4283849 | Cutting unit for a dry-shaving apparatus | Manfred Engelhardt, Jochem J. de Vries, Eduard W. Tietjens | 1981-08-18 |
| 4275497 | Shaving apparatus | Manfred Engelhardt, Jochem J. de Vries, Ferdinand M. Trees, Eduard W. Tietjens, Gerrit J. Groothuis | 1981-06-30 |
| 4262416 | Shaving apparatus | Dirk J. Van Hemmen, Jochem J. de Vries | 1981-04-21 |