HP

Hans-Dieter Piotrowski

Overall (All Time): #1,296,002 of 4,157,543Top 35%
4
Patents All Time

Issued Patents All Time

Showing 1–4 of 4 patents

Patent #TitleCo-InventorsDate
5259464 Percussion mechanism for a drill rod unit Robert-Jan Bartels 1993-11-09
5199658 Dual-force hydraulic drive for a demolition tool Robert-Jan Bartels, Helmar Nafe 1993-04-06
5129466 Hydraulically operated striking mechanism Robert-Jan Bartels 1992-07-14
5117921 Hydraulically operated hammer drill Robert-Jan Bartels 1992-06-02