TREA

John C Marshall

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  • North Bay, CA
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Patents Grantslast 30 patents

  • Information Patent Grant

    Up-hole pump-in core barrel apparatus
    • Patent number 6,425,449
    • Issue date Jul 30, 2002
    • Boart Longyear International Holdings, Inc.
    • John C. Marshall
    • E21 - EARTH DRILLING MINING
  • Information Patent Grant

    Core barrel apparatus
    • Patent number 5,934,393
    • Issue date Aug 10, 1999
    • Boart Longyear International Holdings, Inc.
    • John C Marshall
    • E21 - EARTH DRILLING MINING