Issued Patents All Time
Showing 1–4 of 4 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 7021855 | Clamping device for clamping girders | Hans-Herlof Hardtke | 2006-04-04 |
| 5018607 | Hydraulic dashpot for pipeline systems | Hans-Herlof Hardtke | 1991-05-28 |
| 4396096 | Mechanical shock absorber | Fredrik W. de Groot | 1983-08-02 |
| 4275802 | Mechanical shock absorber | Fredrik W. de Groot | 1981-06-30 |