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Hans-Otto Friedrichs

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  • Wuppertal, DE
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Patents Grantslast 30 patents

  • Information Patent Grant

    Hydraulic advancing support frame
    • Patent number 5,961,254
    • Issue date Oct 5, 1999
    • DBT Deutsch Bergbau-Technik GmbH
    • Hans-Otto Friedrichs
    • E21 - EARTH DRILLING MINING
  • Information Patent Grant

    Hydraulic walking roof-support frame
    • Patent number 4,155,675
    • Issue date May 22, 1979
    • Hermann Hemscheidt Maschinenfabrik GmbH & Co.
    • Hans-Otto Friedrichs
    • E21 - EARTH DRILLING MINING
  • Information Patent Grant

    Hydraulic walking roof-support frame
    • Patent number 4,155,676
    • Issue date May 22, 1979
    • Hermann Hemscheidt Maschinenfabrik GmbH & Co.
    • Hans-Otto Friedrichs
    • E21 - EARTH DRILLING MINING